diff --git a/crates/base-db/src/input.rs b/crates/base-db/src/input.rs
index 3936fd3555..460581f4a6 100644
--- a/crates/base-db/src/input.rs
+++ b/crates/base-db/src/input.rs
@@ -16,9 +16,7 @@ use span::{Edition, EditionedFileId};
 use triomphe::Arc;
 use vfs::{file_set::FileSet, AbsPathBuf, AnchoredPath, FileId, VfsPath};
 
-// Map from crate id to the name of the crate and path of the proc-macro. If the value is `None`,
-// then the crate for the proc-macro hasn't been build yet as the build data is missing.
-pub type ProcMacroPaths = FxHashMap<CrateId, Result<(Option<String>, AbsPathBuf), String>>;
+pub type ProcMacroPaths = FxHashMap<CrateId, Result<(String, AbsPathBuf), String>>;
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]
 pub struct SourceRootId(pub u32);
diff --git a/crates/hir-def/src/body.rs b/crates/hir-def/src/body.rs
index 9e1bff98f8..d3c134f326 100644
--- a/crates/hir-def/src/body.rs
+++ b/crates/hir-def/src/body.rs
@@ -10,7 +10,7 @@ use std::ops::{Deref, Index};
 
 use base_db::CrateId;
 use cfg::{CfgExpr, CfgOptions};
-use hir_expand::{name::Name, InFile};
+use hir_expand::{name::Name, ExpandError, InFile};
 use la_arena::{Arena, ArenaMap, Idx, RawIdx};
 use rustc_hash::FxHashMap;
 use smallvec::SmallVec;
@@ -115,8 +115,7 @@ pub struct SyntheticSyntax;
 #[derive(Debug, Eq, PartialEq)]
 pub enum BodyDiagnostic {
     InactiveCode { node: InFile<SyntaxNodePtr>, cfg: CfgExpr, opts: CfgOptions },
-    MacroError { node: InFile<AstPtr<ast::MacroCall>>, message: String },
-    UnresolvedProcMacro { node: InFile<AstPtr<ast::MacroCall>>, krate: CrateId },
+    MacroError { node: InFile<AstPtr<ast::MacroCall>>, err: ExpandError },
     UnresolvedMacroCall { node: InFile<AstPtr<ast::MacroCall>>, path: ModPath },
     UnreachableLabel { node: InFile<AstPtr<ast::Lifetime>>, name: Name },
     UndeclaredLabel { node: InFile<AstPtr<ast::Lifetime>>, name: Name },
diff --git a/crates/hir-def/src/body/lower.rs b/crates/hir-def/src/body/lower.rs
index fe5264674a..9e30aff8fe 100644
--- a/crates/hir-def/src/body/lower.rs
+++ b/crates/hir-def/src/body/lower.rs
@@ -7,7 +7,7 @@ use base_db::CrateId;
 use either::Either;
 use hir_expand::{
     name::{AsName, Name},
-    ExpandError, InFile,
+    InFile,
 };
 use intern::{sym, Interned, Symbol};
 use rustc_hash::FxHashMap;
@@ -992,20 +992,11 @@ impl ExprCollector<'_> {
             }
         };
         if record_diagnostics {
-            match &res.err {
-                Some(ExpandError::UnresolvedProcMacro(krate)) => {
-                    self.source_map.diagnostics.push(BodyDiagnostic::UnresolvedProcMacro {
-                        node: InFile::new(outer_file, syntax_ptr),
-                        krate: *krate,
-                    });
-                }
-                Some(err) => {
-                    self.source_map.diagnostics.push(BodyDiagnostic::MacroError {
-                        node: InFile::new(outer_file, syntax_ptr),
-                        message: err.to_string(),
-                    });
-                }
-                None => {}
+            if let Some(err) = res.err {
+                self.source_map.diagnostics.push(BodyDiagnostic::MacroError {
+                    node: InFile::new(outer_file, syntax_ptr),
+                    err,
+                });
             }
         }
 
diff --git a/crates/hir-def/src/data.rs b/crates/hir-def/src/data.rs
index 3a3b540c13..c3c2e51fd0 100644
--- a/crates/hir-def/src/data.rs
+++ b/crates/hir-def/src/data.rs
@@ -657,22 +657,18 @@ impl<'a> AssocItemCollector<'a> {
                             // crate failed), skip expansion like we would if it was
                             // disabled. This is analogous to the handling in
                             // `DefCollector::collect_macros`.
-                            if exp.is_dummy() {
-                                self.diagnostics.push(DefDiagnostic::unresolved_proc_macro(
+                            if let Some(err) = exp.as_expand_error(self.module_id.krate) {
+                                self.diagnostics.push(DefDiagnostic::macro_error(
                                     self.module_id.local_id,
-                                    loc.kind,
-                                    loc.def.krate,
+                                    ast_id,
+                                    (*attr.path).clone(),
+                                    err,
                                 ));
-
-                                continue 'attrs;
-                            }
-                            if exp.is_disabled() {
                                 continue 'attrs;
                             }
                         }
 
                         self.macro_calls.push((ast_id, call_id));
-
                         let res =
                             self.expander.enter_expand_id::<ast::MacroItems>(self.db, call_id);
                         self.collect_macro_items(res);
diff --git a/crates/hir-def/src/expander.rs b/crates/hir-def/src/expander.rs
index d1640ad7e5..6d8b4445f7 100644
--- a/crates/hir-def/src/expander.rs
+++ b/crates/hir-def/src/expander.rs
@@ -6,8 +6,8 @@ use base_db::CrateId;
 use cfg::CfgOptions;
 use drop_bomb::DropBomb;
 use hir_expand::{
-    attrs::RawAttrs, mod_path::ModPath, span_map::SpanMap, ExpandError, ExpandResult, HirFileId,
-    InFile, MacroCallId,
+    attrs::RawAttrs, mod_path::ModPath, span_map::SpanMap, ExpandError, ExpandErrorKind,
+    ExpandResult, HirFileId, InFile, Lookup, MacroCallId,
 };
 use limit::Limit;
 use span::SyntaxContextId;
@@ -160,26 +160,30 @@ impl Expander {
             // so don't return overflow error here to avoid diagnostics duplication.
             cov_mark::hit!(overflow_but_not_me);
             return ExpandResult::ok(None);
-        } else if self.recursion_limit.check(self.recursion_depth as usize + 1).is_err() {
-            self.recursion_depth = u32::MAX;
-            cov_mark::hit!(your_stack_belongs_to_me);
-            return ExpandResult::only_err(ExpandError::RecursionOverflow);
         }
 
         let ExpandResult { value, err } = op(self);
         let Some(call_id) = value else {
             return ExpandResult { value: None, err };
         };
+        if self.recursion_limit.check(self.recursion_depth as usize + 1).is_err() {
+            self.recursion_depth = u32::MAX;
+            cov_mark::hit!(your_stack_belongs_to_me);
+            return ExpandResult::only_err(ExpandError::new(
+                db.macro_arg_considering_derives(call_id, &call_id.lookup(db.upcast()).kind).2,
+                ExpandErrorKind::RecursionOverflow,
+            ));
+        }
 
         let macro_file = call_id.as_macro_file();
         let res = db.parse_macro_expansion(macro_file);
 
         let err = err.or(res.err);
         ExpandResult {
-            value: match err {
+            value: match &err {
                 // If proc-macro is disabled or unresolved, we want to expand to a missing expression
                 // instead of an empty tree which might end up in an empty block.
-                Some(ExpandError::UnresolvedProcMacro(_)) => None,
+                Some(e) if matches!(e.kind(), ExpandErrorKind::MissingProcMacroExpander(_)) => None,
                 _ => (|| {
                     let parse = res.value.0.cast::<T>()?;
 
diff --git a/crates/hir-def/src/lib.rs b/crates/hir-def/src/lib.rs
index e96581e1b3..66412b26a0 100644
--- a/crates/hir-def/src/lib.rs
+++ b/crates/hir-def/src/lib.rs
@@ -75,9 +75,7 @@ use base_db::{
     CrateId,
 };
 use hir_expand::{
-    builtin_attr_macro::BuiltinAttrExpander,
-    builtin_derive_macro::BuiltinDeriveExpander,
-    builtin_fn_macro::{BuiltinFnLikeExpander, EagerExpander},
+    builtin::{BuiltinAttrExpander, BuiltinDeriveExpander, BuiltinFnLikeExpander, EagerExpander},
     db::ExpandDatabase,
     eager::expand_eager_macro_input,
     impl_intern_lookup,
@@ -1436,7 +1434,10 @@ impl AsMacroCall for InFile<&ast::MacroCall> {
         });
 
         let Some((call_site, path)) = path else {
-            return Ok(ExpandResult::only_err(ExpandError::other("malformed macro invocation")));
+            return Ok(ExpandResult::only_err(ExpandError::other(
+                span_map.span_for_range(self.value.syntax().text_range()),
+                "malformed macro invocation",
+            )));
         };
 
         macro_call_as_call_id_with_eager(
diff --git a/crates/hir-def/src/macro_expansion_tests/mbe/regression.rs b/crates/hir-def/src/macro_expansion_tests/mbe/regression.rs
index 252b0bb1b5..485f72e92c 100644
--- a/crates/hir-def/src/macro_expansion_tests/mbe/regression.rs
+++ b/crates/hir-def/src/macro_expansion_tests/mbe/regression.rs
@@ -1084,7 +1084,7 @@ fn main() {
 macro_rules! concat_bytes {}
 
 fn main() {
-    let x = /* error: unexpected token in input */b"";
+    let x = /* error: unexpected token */b"";
 }
 
 "#]],
diff --git a/crates/hir-def/src/macro_expansion_tests/mod.rs b/crates/hir-def/src/macro_expansion_tests/mod.rs
index b6c6e4b397..d34f0afc3e 100644
--- a/crates/hir-def/src/macro_expansion_tests/mod.rs
+++ b/crates/hir-def/src/macro_expansion_tests/mod.rs
@@ -122,7 +122,7 @@ pub fn identity_when_valid(_attr: TokenStream, item: TokenStream) -> TokenStream
 
         let mut expn_text = String::new();
         if let Some(err) = exp.err {
-            format_to!(expn_text, "/* error: {} */", err);
+            format_to!(expn_text, "/* error: {} */", err.render_to_string(&db).0);
         }
         let (parse, token_map) = exp.value;
         if expect_errors {
diff --git a/crates/hir-def/src/nameres.rs b/crates/hir-def/src/nameres.rs
index 08a4eab1bc..8825e46336 100644
--- a/crates/hir-def/src/nameres.rs
+++ b/crates/hir-def/src/nameres.rs
@@ -145,8 +145,6 @@ struct DefMapCrateData {
     /// Side table for resolving derive helpers.
     exported_derives: FxHashMap<MacroDefId, Box<[Name]>>,
     fn_proc_macro_mapping: FxHashMap<FunctionId, ProcMacroId>,
-    /// The error that occurred when failing to load the proc-macro dll.
-    proc_macro_loading_error: Option<Box<str>>,
 
     /// Custom attributes registered with `#![register_attr]`.
     registered_attrs: Vec<Symbol>,
@@ -169,7 +167,6 @@ impl DefMapCrateData {
             extern_prelude: FxIndexMap::default(),
             exported_derives: FxHashMap::default(),
             fn_proc_macro_mapping: FxHashMap::default(),
-            proc_macro_loading_error: None,
             registered_attrs: Vec::new(),
             registered_tools: PREDEFINED_TOOLS.iter().map(|it| Symbol::intern(it)).collect(),
             unstable_features: FxHashSet::default(),
@@ -189,7 +186,6 @@ impl DefMapCrateData {
             registered_attrs,
             registered_tools,
             unstable_features,
-            proc_macro_loading_error: _,
             rustc_coherence_is_core: _,
             no_core: _,
             no_std: _,
@@ -474,10 +470,6 @@ impl DefMap {
         self.data.fn_proc_macro_mapping.get(&id).copied()
     }
 
-    pub fn proc_macro_loading_error(&self) -> Option<&str> {
-        self.data.proc_macro_loading_error.as_deref()
-    }
-
     pub fn krate(&self) -> CrateId {
         self.krate
     }
diff --git a/crates/hir-def/src/nameres/collector.rs b/crates/hir-def/src/nameres/collector.rs
index 6f435d1f58..483bffc4b2 100644
--- a/crates/hir-def/src/nameres/collector.rs
+++ b/crates/hir-def/src/nameres/collector.rs
@@ -10,9 +10,7 @@ use cfg::{CfgExpr, CfgOptions};
 use either::Either;
 use hir_expand::{
     attrs::{Attr, AttrId},
-    builtin_attr_macro::find_builtin_attr,
-    builtin_derive_macro::find_builtin_derive,
-    builtin_fn_macro::find_builtin_macro,
+    builtin::{find_builtin_attr, find_builtin_derive, find_builtin_macro},
     name::{AsName, Name},
     proc_macro::CustomProcMacroExpander,
     ExpandTo, HirFileId, InFile, MacroCallId, MacroCallKind, MacroDefId, MacroDefKind,
@@ -76,34 +74,11 @@ pub(super) fn collect_defs(db: &dyn DefDatabase, def_map: DefMap, tree_id: TreeI
     }
 
     let proc_macros = if krate.is_proc_macro {
-        match db.proc_macros().get(&def_map.krate) {
-            Some(Ok(proc_macros)) => Ok({
-                let ctx = db.syntax_context(tree_id.file_id());
-                proc_macros
-                    .iter()
-                    .enumerate()
-                    .map(|(idx, it)| {
-                        let name = Name::new_symbol(it.name.clone(), ctx);
-                        (
-                            name,
-                            if !db.expand_proc_attr_macros() {
-                                CustomProcMacroExpander::dummy()
-                            } else if it.disabled {
-                                CustomProcMacroExpander::disabled()
-                            } else {
-                                CustomProcMacroExpander::new(
-                                    hir_expand::proc_macro::ProcMacroId::new(idx as u32),
-                                )
-                            },
-                        )
-                    })
-                    .collect()
-            }),
-            Some(Err(e)) => Err(e.clone().into_boxed_str()),
-            None => Err("No proc-macros present for crate".to_owned().into_boxed_str()),
-        }
+        db.proc_macros()
+            .for_crate(def_map.krate, db.syntax_context(tree_id.file_id()))
+            .unwrap_or_default()
     } else {
-        Ok(vec![])
+        Default::default()
     };
 
     let mut collector = DefCollector {
@@ -252,10 +227,10 @@ struct DefCollector<'a> {
     mod_dirs: FxHashMap<LocalModuleId, ModDir>,
     cfg_options: &'a CfgOptions,
     /// List of procedural macros defined by this crate. This is read from the dynamic library
-    /// built by the build system, and is the list of proc. macros we can actually expand. It is
-    /// empty when proc. macro support is disabled (in which case we still do name resolution for
-    /// them).
-    proc_macros: Result<Vec<(Name, CustomProcMacroExpander)>, Box<str>>,
+    /// built by the build system, and is the list of proc-macros we can actually expand. It is
+    /// empty when proc-macro support is disabled (in which case we still do name resolution for
+    /// them). The bool signals whether the proc-macro has been explicitly disabled for name-resolution.
+    proc_macros: Box<[(Name, CustomProcMacroExpander, bool)]>,
     is_proc_macro: bool,
     from_glob_import: PerNsGlobImports,
     /// If we fail to resolve an attribute on a `ModItem`, we fall back to ignoring the attribute.
@@ -278,10 +253,6 @@ impl DefCollector<'_> {
         let attrs = item_tree.top_level_attrs(self.db, self.def_map.krate);
         let crate_data = Arc::get_mut(&mut self.def_map.data).unwrap();
 
-        if let Err(e) = &self.proc_macros {
-            crate_data.proc_macro_loading_error = Some(e.clone());
-        }
-
         let mut process = true;
 
         // Process other crate-level attributes.
@@ -608,11 +579,17 @@ impl DefCollector<'_> {
         fn_id: FunctionId,
     ) {
         let kind = def.kind.to_basedb_kind();
-        let (expander, kind) =
-            match self.proc_macros.as_ref().map(|it| it.iter().find(|(n, _)| n == &def.name)) {
-                Ok(Some(&(_, expander))) => (expander, kind),
-                _ => (CustomProcMacroExpander::dummy(), kind),
-            };
+        let (expander, kind) = match self.proc_macros.iter().find(|(n, _, _)| n == &def.name) {
+            Some(_)
+                if kind == hir_expand::proc_macro::ProcMacroKind::Attr
+                    && !self.db.expand_proc_attr_macros() =>
+            {
+                (CustomProcMacroExpander::disabled_proc_attr(), kind)
+            }
+            Some(&(_, _, true)) => (CustomProcMacroExpander::disabled(), kind),
+            Some(&(_, expander, false)) => (expander, kind),
+            None => (CustomProcMacroExpander::missing_expander(), kind),
+        };
 
         let proc_macro_id = ProcMacroLoc {
             container: self.def_map.crate_root(),
@@ -1415,25 +1392,23 @@ impl DefCollector<'_> {
                         return recollect_without(self);
                     }
 
-                    let call_id = call_id();
                     if let MacroDefKind::ProcMacro(_, exp, _) = def.kind {
                         // If there's no expander for the proc macro (e.g.
                         // because proc macros are disabled, or building the
                         // proc macro crate failed), report this and skip
                         // expansion like we would if it was disabled
-                        if exp.is_dummy() {
-                            self.def_map.diagnostics.push(DefDiagnostic::unresolved_proc_macro(
+                        if let Some(err) = exp.as_expand_error(def.krate) {
+                            self.def_map.diagnostics.push(DefDiagnostic::macro_error(
                                 directive.module_id,
-                                self.db.lookup_intern_macro_call(call_id).kind,
-                                def.krate,
+                                ast_id,
+                                (**path).clone(),
+                                err,
                             ));
                             return recollect_without(self);
                         }
-                        if exp.is_disabled() {
-                            return recollect_without(self);
-                        }
                     }
 
+                    let call_id = call_id();
                     self.def_map.modules[directive.module_id]
                         .scope
                         .add_attr_macro_invoc(ast_id, call_id);
@@ -1472,7 +1447,6 @@ impl DefCollector<'_> {
         }
         let file_id = macro_call_id.as_file();
 
-        // Then, fetch and process the item tree. This will reuse the expansion result from above.
         let item_tree = self.db.file_item_tree(file_id);
 
         let mod_dir = if macro_call_id.as_macro_file().is_include_macro(self.db.upcast()) {
@@ -2510,7 +2484,7 @@ mod tests {
             unresolved_macros: Vec::new(),
             mod_dirs: FxHashMap::default(),
             cfg_options: &CfgOptions::default(),
-            proc_macros: Ok(vec![]),
+            proc_macros: Default::default(),
             from_glob_import: Default::default(),
             skip_attrs: Default::default(),
             is_proc_macro: false,
diff --git a/crates/hir-def/src/nameres/diagnostics.rs b/crates/hir-def/src/nameres/diagnostics.rs
index e1bd6966f3..bc1617c55b 100644
--- a/crates/hir-def/src/nameres/diagnostics.rs
+++ b/crates/hir-def/src/nameres/diagnostics.rs
@@ -2,9 +2,8 @@
 
 use std::ops::Not;
 
-use base_db::CrateId;
 use cfg::{CfgExpr, CfgOptions};
-use hir_expand::{attrs::AttrId, MacroCallKind};
+use hir_expand::{attrs::AttrId, ExpandErrorKind, MacroCallKind};
 use la_arena::Idx;
 use syntax::ast;
 
@@ -17,48 +16,16 @@ use crate::{
 
 #[derive(Debug, PartialEq, Eq)]
 pub enum DefDiagnosticKind {
-    UnresolvedModule {
-        ast: AstId<ast::Module>,
-        candidates: Box<[String]>,
-    },
-    UnresolvedExternCrate {
-        ast: AstId<ast::ExternCrate>,
-    },
-    UnresolvedImport {
-        id: ItemTreeId<item_tree::Use>,
-        index: Idx<ast::UseTree>,
-    },
-    UnconfiguredCode {
-        tree: TreeId,
-        item: AttrOwner,
-        cfg: CfgExpr,
-        opts: CfgOptions,
-    },
-    /// A proc-macro that is lacking an expander, this might be due to build scripts not yet having
-    /// run or proc-macro expansion being disabled.
-    UnresolvedProcMacro {
-        ast: MacroCallKind,
-        krate: CrateId,
-    },
-    UnresolvedMacroCall {
-        ast: MacroCallKind,
-        path: ModPath,
-    },
-    UnimplementedBuiltinMacro {
-        ast: AstId<ast::Macro>,
-    },
-    InvalidDeriveTarget {
-        ast: AstId<ast::Item>,
-        id: usize,
-    },
-    MalformedDerive {
-        ast: AstId<ast::Adt>,
-        id: usize,
-    },
-    MacroDefError {
-        ast: AstId<ast::Macro>,
-        message: String,
-    },
+    UnresolvedModule { ast: AstId<ast::Module>, candidates: Box<[String]> },
+    UnresolvedExternCrate { ast: AstId<ast::ExternCrate> },
+    UnresolvedImport { id: ItemTreeId<item_tree::Use>, index: Idx<ast::UseTree> },
+    UnconfiguredCode { tree: TreeId, item: AttrOwner, cfg: CfgExpr, opts: CfgOptions },
+    UnresolvedMacroCall { ast: MacroCallKind, path: ModPath },
+    UnimplementedBuiltinMacro { ast: AstId<ast::Macro> },
+    InvalidDeriveTarget { ast: AstId<ast::Item>, id: usize },
+    MalformedDerive { ast: AstId<ast::Adt>, id: usize },
+    MacroDefError { ast: AstId<ast::Macro>, message: String },
+    MacroError { ast: AstId<ast::Item>, path: ModPath, err: ExpandErrorKind },
 }
 
 #[derive(Clone, Debug, PartialEq, Eq)]
@@ -115,6 +82,15 @@ impl DefDiagnostic {
         Self { in_module: container, kind: DefDiagnosticKind::UnresolvedImport { id, index } }
     }
 
+    pub fn macro_error(
+        container: LocalModuleId,
+        ast: AstId<ast::Item>,
+        path: ModPath,
+        err: ExpandErrorKind,
+    ) -> Self {
+        Self { in_module: container, kind: DefDiagnosticKind::MacroError { ast, path, err } }
+    }
+
     pub fn unconfigured_code(
         container: LocalModuleId,
         tree: TreeId,
@@ -128,14 +104,6 @@ impl DefDiagnostic {
         }
     }
 
-    pub fn unresolved_proc_macro(
-        container: LocalModuleId,
-        ast: MacroCallKind,
-        krate: CrateId,
-    ) -> Self {
-        Self { in_module: container, kind: DefDiagnosticKind::UnresolvedProcMacro { ast, krate } }
-    }
-
     // FIXME: Whats the difference between this and unresolved_proc_macro
     pub(crate) fn unresolved_macro_call(
         container: LocalModuleId,
diff --git a/crates/hir-expand/src/builtin.rs b/crates/hir-expand/src/builtin.rs
new file mode 100644
index 0000000000..252430e4e9
--- /dev/null
+++ b/crates/hir-expand/src/builtin.rs
@@ -0,0 +1,15 @@
+//! Builtin macros and attributes
+#[macro_use]
+mod quote;
+
+mod attr_macro;
+mod derive_macro;
+mod fn_macro;
+
+pub use self::{
+    attr_macro::{find_builtin_attr, pseudo_derive_attr_expansion, BuiltinAttrExpander},
+    derive_macro::{find_builtin_derive, BuiltinDeriveExpander},
+    fn_macro::{
+        find_builtin_macro, include_input_to_file_id, BuiltinFnLikeExpander, EagerExpander,
+    },
+};
diff --git a/crates/hir-expand/src/builtin_attr_macro.rs b/crates/hir-expand/src/builtin/attr_macro.rs
similarity index 100%
rename from crates/hir-expand/src/builtin_attr_macro.rs
rename to crates/hir-expand/src/builtin/attr_macro.rs
diff --git a/crates/hir-expand/src/builtin_derive_macro.rs b/crates/hir-expand/src/builtin/derive_macro.rs
similarity index 96%
rename from crates/hir-expand/src/builtin_derive_macro.rs
rename to crates/hir-expand/src/builtin/derive_macro.rs
index d168bad703..f560d3bfd1 100644
--- a/crates/hir-expand/src/builtin_derive_macro.rs
+++ b/crates/hir-expand/src/builtin/derive_macro.rs
@@ -9,18 +9,17 @@ use stdx::never;
 use tracing::debug;
 
 use crate::{
+    builtin::quote::{dollar_crate, quote},
+    db::ExpandDatabase,
     hygiene::span_with_def_site_ctxt,
-    name::{AsName, Name},
-    quote::dollar_crate,
+    name::{self, AsName, Name},
     span_map::ExpansionSpanMap,
-    tt,
+    tt, ExpandError, ExpandResult,
 };
 use syntax::ast::{
     self, AstNode, FieldList, HasAttrs, HasGenericParams, HasModuleItem, HasName, HasTypeBounds,
 };
 
-use crate::{db::ExpandDatabase, name, quote, ExpandError, ExpandResult};
-
 macro_rules! register_builtin {
     ( $($trait:ident => $expand:ident),* ) => {
         #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
@@ -129,13 +128,17 @@ impl VariantShape {
         }
     }
 
-    fn from(tm: &ExpansionSpanMap, value: Option<FieldList>) -> Result<Self, ExpandError> {
+    fn from(
+        call_site: Span,
+        tm: &ExpansionSpanMap,
+        value: Option<FieldList>,
+    ) -> Result<Self, ExpandError> {
         let r = match value {
             None => VariantShape::Unit,
             Some(FieldList::RecordFieldList(it)) => VariantShape::Struct(
                 it.fields()
                     .map(|it| it.name())
-                    .map(|it| name_to_token(tm, it))
+                    .map(|it| name_to_token(call_site, tm, it))
                     .collect::<Result<_, _>>()?,
             ),
             Some(FieldList::TupleFieldList(it)) => VariantShape::Tuple(it.fields().count()),
@@ -212,16 +215,17 @@ fn parse_adt(tt: &tt::Subtree, call_site: Span) -> Result<BasicAdtInfo, ExpandEr
         parser::Edition::CURRENT_FIXME,
     );
     let macro_items = ast::MacroItems::cast(parsed.syntax_node())
-        .ok_or_else(|| ExpandError::other("invalid item definition"))?;
-    let item = macro_items.items().next().ok_or_else(|| ExpandError::other("no item found"))?;
+        .ok_or_else(|| ExpandError::other(call_site, "invalid item definition"))?;
+    let item =
+        macro_items.items().next().ok_or_else(|| ExpandError::other(call_site, "no item found"))?;
     let adt = &ast::Adt::cast(item.syntax().clone())
-        .ok_or_else(|| ExpandError::other("expected struct, enum or union"))?;
+        .ok_or_else(|| ExpandError::other(call_site, "expected struct, enum or union"))?;
     let (name, generic_param_list, where_clause, shape) = match adt {
         ast::Adt::Struct(it) => (
             it.name(),
             it.generic_param_list(),
             it.where_clause(),
-            AdtShape::Struct(VariantShape::from(tm, it.field_list())?),
+            AdtShape::Struct(VariantShape::from(call_site, tm, it.field_list())?),
         ),
         ast::Adt::Enum(it) => {
             let default_variant = it
@@ -241,8 +245,8 @@ fn parse_adt(tt: &tt::Subtree, call_site: Span) -> Result<BasicAdtInfo, ExpandEr
                         .flat_map(|it| it.variants())
                         .map(|it| {
                             Ok((
-                                name_to_token(tm, it.name())?,
-                                VariantShape::from(tm, it.field_list())?,
+                                name_to_token(call_site, tm, it.name())?,
+                                VariantShape::from(call_site, tm, it.field_list())?,
                             ))
                         })
                         .collect::<Result<_, ExpandError>>()?,
@@ -357,17 +361,18 @@ fn parse_adt(tt: &tt::Subtree, call_site: Span) -> Result<BasicAdtInfo, ExpandEr
             )
         })
         .collect();
-    let name_token = name_to_token(tm, name)?;
+    let name_token = name_to_token(call_site, tm, name)?;
     Ok(BasicAdtInfo { name: name_token, shape, param_types, where_clause, associated_types })
 }
 
 fn name_to_token(
+    call_site: Span,
     token_map: &ExpansionSpanMap,
     name: Option<ast::Name>,
 ) -> Result<tt::Ident, ExpandError> {
     let name = name.ok_or_else(|| {
         debug!("parsed item has no name");
-        ExpandError::other("missing name")
+        ExpandError::other(call_site, "missing name")
     })?;
     let span = token_map.span_at(name.syntax().text_range().start());
 
diff --git a/crates/hir-expand/src/builtin_fn_macro.rs b/crates/hir-expand/src/builtin/fn_macro.rs
similarity index 92%
rename from crates/hir-expand/src/builtin_fn_macro.rs
rename to crates/hir-expand/src/builtin/fn_macro.rs
index 2725bdb768..391b891ad6 100644
--- a/crates/hir-expand/src/builtin_fn_macro.rs
+++ b/crates/hir-expand/src/builtin/fn_macro.rs
@@ -13,10 +13,10 @@ use syntax::{
 };
 
 use crate::{
+    builtin::quote::{dollar_crate, quote},
     db::ExpandDatabase,
     hygiene::{span_with_call_site_ctxt, span_with_def_site_ctxt},
-    name, quote,
-    quote::dollar_crate,
+    name,
     tt::{self, DelimSpan},
     ExpandError, ExpandResult, HirFileIdExt, Lookup as _, MacroCallId,
 };
@@ -145,7 +145,7 @@ register_builtin! {
 }
 
 fn mk_pound(span: Span) -> tt::Subtree {
-    crate::quote::IntoTt::to_subtree(
+    crate::builtin::quote::IntoTt::to_subtree(
         vec![crate::tt::Leaf::Punct(crate::tt::Punct {
             char: '#',
             spacing: crate::tt::Spacing::Alone,
@@ -463,12 +463,8 @@ fn compile_error_expand(
             span: _,
             kind: tt::LitKind::Str | tt::LitKind::StrRaw(_),
             suffix: _,
-        }))] =>
-        // FIXME: Use the span here!
-        {
-            ExpandError::other(Box::from(unescape_str(text).as_str()))
-        }
-        _ => ExpandError::other("`compile_error!` argument must be a string"),
+        }))] => ExpandError::other(span, Box::from(unescape_str(text).as_str())),
+        _ => ExpandError::other(span, "`compile_error!` argument must be a string"),
     };
 
     ExpandResult { value: quote! {span =>}, err: Some(err) }
@@ -478,7 +474,7 @@ fn concat_expand(
     _db: &dyn ExpandDatabase,
     _arg_id: MacroCallId,
     tt: &tt::Subtree,
-    _: Span,
+    call_site: Span,
 ) -> ExpandResult<tt::Subtree> {
     let mut err = None;
     let mut text = String::new();
@@ -527,7 +523,9 @@ fn concat_expand(
                     | tt::LitKind::ByteStrRaw(_)
                     | tt::LitKind::CStr
                     | tt::LitKind::CStrRaw(_)
-                    | tt::LitKind::Err(_) => err = Some(ExpandError::other("unexpected literal")),
+                    | tt::LitKind::Err(_) => {
+                        err = Some(ExpandError::other(it.span, "unexpected literal"))
+                    }
                 }
             }
             // handle boolean literals
@@ -539,7 +537,7 @@ fn concat_expand(
             }
             tt::TokenTree::Leaf(tt::Leaf::Punct(punct)) if i % 2 == 1 && punct.char == ',' => (),
             _ => {
-                err.get_or_insert(mbe::ExpandError::UnexpectedToken.into());
+                err.get_or_insert(ExpandError::other(call_site, "unexpected token"));
             }
         }
     }
@@ -551,7 +549,7 @@ fn concat_bytes_expand(
     _db: &dyn ExpandDatabase,
     _arg_id: MacroCallId,
     tt: &tt::Subtree,
-    _: Span,
+    call_site: Span,
 ) -> ExpandResult<tt::Subtree> {
     let mut bytes = String::new();
     let mut err = None;
@@ -585,20 +583,22 @@ fn concat_bytes_expand(
                         bytes.extend(text.as_str().escape_debug());
                     }
                     _ => {
-                        err.get_or_insert(mbe::ExpandError::UnexpectedToken.into());
+                        err.get_or_insert(ExpandError::other(*span, "unexpected token"));
                         break;
                     }
                 }
             }
             tt::TokenTree::Leaf(tt::Leaf::Punct(punct)) if i % 2 == 1 && punct.char == ',' => (),
             tt::TokenTree::Subtree(tree) if tree.delimiter.kind == tt::DelimiterKind::Bracket => {
-                if let Err(e) = concat_bytes_expand_subtree(tree, &mut bytes, &mut record_span) {
+                if let Err(e) =
+                    concat_bytes_expand_subtree(tree, &mut bytes, &mut record_span, call_site)
+                {
                     err.get_or_insert(e);
                     break;
                 }
             }
             _ => {
-                err.get_or_insert(mbe::ExpandError::UnexpectedToken.into());
+                err.get_or_insert(ExpandError::other(call_site, "unexpected token"));
                 break;
             }
         }
@@ -623,6 +623,7 @@ fn concat_bytes_expand_subtree(
     tree: &tt::Subtree,
     bytes: &mut String,
     mut record_span: impl FnMut(Span),
+    err_span: Span,
 ) -> Result<(), ExpandError> {
     for (ti, tt) in tree.token_trees.iter().enumerate() {
         match tt {
@@ -650,7 +651,7 @@ fn concat_bytes_expand_subtree(
             }
             tt::TokenTree::Leaf(tt::Leaf::Punct(punct)) if ti % 2 == 1 && punct.char == ',' => (),
             _ => {
-                return Err(mbe::ExpandError::UnexpectedToken.into());
+                return Err(ExpandError::other(err_span, "unexpected token"));
             }
         }
     }
@@ -672,7 +673,7 @@ fn concat_idents_expand(
             }
             tt::TokenTree::Leaf(tt::Leaf::Punct(punct)) if i % 2 == 1 && punct.char == ',' => (),
             _ => {
-                err.get_or_insert(mbe::ExpandError::UnexpectedToken.into());
+                err.get_or_insert(ExpandError::other(span, "unexpected token"));
             }
         }
     }
@@ -686,16 +687,17 @@ fn relative_file(
     call_id: MacroCallId,
     path_str: &str,
     allow_recursion: bool,
+    err_span: Span,
 ) -> Result<EditionedFileId, ExpandError> {
     let lookup = call_id.lookup(db);
     let call_site = lookup.kind.file_id().original_file_respecting_includes(db).file_id();
     let path = AnchoredPath { anchor: call_site, path: path_str };
     let res = db
         .resolve_path(path)
-        .ok_or_else(|| ExpandError::other(format!("failed to load file `{path_str}`")))?;
+        .ok_or_else(|| ExpandError::other(err_span, format!("failed to load file `{path_str}`")))?;
     // Prevent include itself
     if res == call_site && !allow_recursion {
-        Err(ExpandError::other(format!("recursive inclusion of `{path_str}`")))
+        Err(ExpandError::other(err_span, format!("recursive inclusion of `{path_str}`")))
     } else {
         Ok(EditionedFileId::new(res, db.crate_graph()[lookup.krate].edition))
     }
@@ -704,18 +706,19 @@ fn relative_file(
 fn parse_string(tt: &tt::Subtree) -> Result<(Symbol, Span), ExpandError> {
     tt.token_trees
         .first()
+        .ok_or(tt.delimiter.open.cover(tt.delimiter.close))
         .and_then(|tt| match tt {
             tt::TokenTree::Leaf(tt::Leaf::Literal(tt::Literal {
                 symbol: text,
                 span,
                 kind: tt::LitKind::Str,
                 suffix: _,
-            })) => Some((unescape_str(text), *span)),
+            })) => Ok((unescape_str(text), *span)),
             // FIXME: We wrap expression fragments in parentheses which can break this expectation
             // here
             // Remove this once we handle none delims correctly
-            tt::TokenTree::Subtree(t) if t.delimiter.kind == DelimiterKind::Parenthesis => {
-                t.token_trees.first().and_then(|tt| match tt {
+            tt::TokenTree::Subtree(tt) if tt.delimiter.kind == DelimiterKind::Parenthesis => {
+                tt.token_trees.first().and_then(|tt| match tt {
                     tt::TokenTree::Leaf(tt::Leaf::Literal(tt::Literal {
                         symbol: text,
                         span,
@@ -725,9 +728,11 @@ fn parse_string(tt: &tt::Subtree) -> Result<(Symbol, Span), ExpandError> {
                     _ => None,
                 })
             }
-            _ => None,
+            .ok_or(tt.delimiter.open.cover(tt.delimiter.close)),
+            ::tt::TokenTree::Leaf(l) => Err(*l.span()),
+            ::tt::TokenTree::Subtree(tt) => Err(tt.delimiter.open.cover(tt.delimiter.close)),
         })
-        .ok_or(mbe::ExpandError::ConversionError.into())
+        .map_err(|span| ExpandError::other(span, "expected string literal"))
 }
 
 fn include_expand(
@@ -751,7 +756,7 @@ fn include_expand(
         Some(it) => ExpandResult::ok(it),
         None => ExpandResult::new(
             tt::Subtree::empty(DelimSpan { open: span, close: span }),
-            ExpandError::other("failed to parse included file"),
+            ExpandError::other(span, "failed to parse included file"),
         ),
     }
 }
@@ -761,7 +766,8 @@ pub fn include_input_to_file_id(
     arg_id: MacroCallId,
     arg: &tt::Subtree,
 ) -> Result<EditionedFileId, ExpandError> {
-    relative_file(db, arg_id, parse_string(arg)?.0.as_str(), false)
+    let (s, span) = parse_string(arg)?;
+    relative_file(db, arg_id, s.as_str(), false, span)
 }
 
 fn include_bytes_expand(
@@ -800,7 +806,7 @@ fn include_str_expand(
     // it's unusual to `include_str!` a Rust file), but we can return an empty string.
     // Ideally, we'd be able to offer a precise expansion if the user asks for macro
     // expansion.
-    let file_id = match relative_file(db, arg_id, path.as_str(), true) {
+    let file_id = match relative_file(db, arg_id, path.as_str(), true, span) {
         Ok(file_id) => file_id,
         Err(_) => {
             return ExpandResult::ok(quote!(span =>""));
@@ -836,7 +842,10 @@ fn env_expand(
         // The only variable rust-analyzer ever sets is `OUT_DIR`, so only diagnose that to avoid
         // unnecessary diagnostics for eg. `CARGO_PKG_NAME`.
         if key.as_str() == "OUT_DIR" {
-            err = Some(ExpandError::other(r#"`OUT_DIR` not set, enable "build scripts" to fix"#));
+            err = Some(ExpandError::other(
+                span,
+                r#"`OUT_DIR` not set, enable "build scripts" to fix"#,
+            ));
         }
 
         // If the variable is unset, still return a dummy string to help type inference along.
@@ -885,7 +894,7 @@ fn quote_expand(
 ) -> ExpandResult<tt::Subtree> {
     ExpandResult::new(
         tt::Subtree::empty(tt::DelimSpan { open: span, close: span }),
-        ExpandError::other("quote! is not implemented"),
+        ExpandError::other(span, "quote! is not implemented"),
     )
 }
 
diff --git a/crates/hir-expand/src/quote.rs b/crates/hir-expand/src/builtin/quote.rs
similarity index 79%
rename from crates/hir-expand/src/quote.rs
rename to crates/hir-expand/src/builtin/quote.rs
index da02f3aaf9..5c33f817f9 100644
--- a/crates/hir-expand/src/quote.rs
+++ b/crates/hir-expand/src/builtin/quote.rs
@@ -17,22 +17,21 @@ pub(crate) fn dollar_crate(span: Span) -> tt::Ident<Span> {
 // 2. #()* pattern repetition not supported now
 //    * But we can do it manually, see `test_quote_derive_copy_hack`
 #[doc(hidden)]
-#[macro_export]
-macro_rules! __quote {
+macro_rules! quote_impl__ {
     ($span:ident) => {
         Vec::<$crate::tt::TokenTree>::new()
     };
 
     ( @SUBTREE($span:ident) $delim:ident $($tt:tt)* ) => {
         {
-            let children = $crate::__quote!($span $($tt)*);
+            let children = $crate::builtin::quote::__quote!($span $($tt)*);
             $crate::tt::Subtree {
                 delimiter: crate::tt::Delimiter {
                     kind: crate::tt::DelimiterKind::$delim,
                     open: $span,
                     close: $span,
                 },
-                token_trees: $crate::quote::IntoTt::to_tokens(children).into_boxed_slice(),
+                token_trees: $crate::builtin::quote::IntoTt::to_tokens(children).into_boxed_slice(),
             }
         }
     };
@@ -69,9 +68,9 @@ macro_rules! __quote {
     // hash variable
     ($span:ident # $first:ident $($tail:tt)* ) => {
         {
-            let token = $crate::quote::ToTokenTree::to_token($first, $span);
+            let token = $crate::builtin::quote::ToTokenTree::to_token($first, $span);
             let mut tokens = vec![token.into()];
-            let mut tail_tokens = $crate::quote::IntoTt::to_tokens($crate::__quote!($span $($tail)*));
+            let mut tail_tokens = $crate::builtin::quote::IntoTt::to_tokens($crate::builtin::quote::__quote!($span $($tail)*));
             tokens.append(&mut tail_tokens);
             tokens
         }
@@ -79,22 +78,22 @@ macro_rules! __quote {
 
     ($span:ident ## $first:ident $($tail:tt)* ) => {
         {
-            let mut tokens = $first.into_iter().map(|it| $crate::quote::ToTokenTree::to_token(it, $span)).collect::<Vec<crate::tt::TokenTree>>();
-            let mut tail_tokens = $crate::quote::IntoTt::to_tokens($crate::__quote!($span $($tail)*));
+            let mut tokens = $first.into_iter().map(|it| $crate::builtin::quote::ToTokenTree::to_token(it, $span)).collect::<Vec<crate::tt::TokenTree>>();
+            let mut tail_tokens = $crate::builtin::quote::IntoTt::to_tokens($crate::builtin::quote::__quote!($span $($tail)*));
             tokens.append(&mut tail_tokens);
             tokens
         }
     };
 
     // Brace
-    ($span:ident  { $($tt:tt)* } ) => { $crate::__quote!(@SUBTREE($span) Brace $($tt)*) };
+    ($span:ident  { $($tt:tt)* } ) => { $crate::builtin::quote::__quote!(@SUBTREE($span) Brace $($tt)*) };
     // Bracket
-    ($span:ident  [ $($tt:tt)* ] ) => { $crate::__quote!(@SUBTREE($span) Bracket $($tt)*) };
+    ($span:ident  [ $($tt:tt)* ] ) => { $crate::builtin::quote::__quote!(@SUBTREE($span) Bracket $($tt)*) };
     // Parenthesis
-    ($span:ident  ( $($tt:tt)* ) ) => { $crate::__quote!(@SUBTREE($span) Parenthesis $($tt)*) };
+    ($span:ident  ( $($tt:tt)* ) ) => { $crate::builtin::quote::__quote!(@SUBTREE($span) Parenthesis $($tt)*) };
 
     // Literal
-    ($span:ident $tt:literal ) => { vec![$crate::quote::ToTokenTree::to_token($tt, $span).into()] };
+    ($span:ident $tt:literal ) => { vec![$crate::builtin::quote::ToTokenTree::to_token($tt, $span).into()] };
     // Ident
     ($span:ident $tt:ident ) => {
         vec![ {
@@ -108,36 +107,37 @@ macro_rules! __quote {
 
     // Puncts
     // FIXME: Not all puncts are handled
-    ($span:ident -> ) => {$crate::__quote!(@PUNCT($span) '-', '>')};
-    ($span:ident & ) => {$crate::__quote!(@PUNCT($span) '&')};
-    ($span:ident , ) => {$crate::__quote!(@PUNCT($span) ',')};
-    ($span:ident : ) => {$crate::__quote!(@PUNCT($span) ':')};
-    ($span:ident ; ) => {$crate::__quote!(@PUNCT($span) ';')};
-    ($span:ident :: ) => {$crate::__quote!(@PUNCT($span) ':', ':')};
-    ($span:ident . ) => {$crate::__quote!(@PUNCT($span) '.')};
-    ($span:ident < ) => {$crate::__quote!(@PUNCT($span) '<')};
-    ($span:ident > ) => {$crate::__quote!(@PUNCT($span) '>')};
-    ($span:ident ! ) => {$crate::__quote!(@PUNCT($span) '!')};
+    ($span:ident -> ) => {$crate::builtin::quote::__quote!(@PUNCT($span) '-', '>')};
+    ($span:ident & ) => {$crate::builtin::quote::__quote!(@PUNCT($span) '&')};
+    ($span:ident , ) => {$crate::builtin::quote::__quote!(@PUNCT($span) ',')};
+    ($span:ident : ) => {$crate::builtin::quote::__quote!(@PUNCT($span) ':')};
+    ($span:ident ; ) => {$crate::builtin::quote::__quote!(@PUNCT($span) ';')};
+    ($span:ident :: ) => {$crate::builtin::quote::__quote!(@PUNCT($span) ':', ':')};
+    ($span:ident . ) => {$crate::builtin::quote::__quote!(@PUNCT($span) '.')};
+    ($span:ident < ) => {$crate::builtin::quote::__quote!(@PUNCT($span) '<')};
+    ($span:ident > ) => {$crate::builtin::quote::__quote!(@PUNCT($span) '>')};
+    ($span:ident ! ) => {$crate::builtin::quote::__quote!(@PUNCT($span) '!')};
 
     ($span:ident $first:tt $($tail:tt)+ ) => {
         {
-            let mut tokens = $crate::quote::IntoTt::to_tokens($crate::__quote!($span $first ));
-            let mut tail_tokens = $crate::quote::IntoTt::to_tokens($crate::__quote!($span $($tail)*));
+            let mut tokens = $crate::builtin::quote::IntoTt::to_tokens($crate::builtin::quote::__quote!($span $first ));
+            let mut tail_tokens = $crate::builtin::quote::IntoTt::to_tokens($crate::builtin::quote::__quote!($span $($tail)*));
 
             tokens.append(&mut tail_tokens);
             tokens
         }
     };
 }
+pub(super) use quote_impl__ as __quote;
 
 /// FIXME:
 /// It probably should implement in proc-macro
-#[macro_export]
-macro_rules! quote {
+macro_rules! quote_impl {
     ($span:ident=> $($tt:tt)* ) => {
-        $crate::quote::IntoTt::to_subtree($crate::__quote!($span $($tt)*), $span)
+        $crate::builtin::quote::IntoTt::to_subtree($crate::builtin::quote::__quote!($span $($tt)*), $span)
     }
 }
+pub(super) use quote_impl as quote;
 
 pub(crate) trait IntoTt {
     fn to_subtree(self, span: Span) -> crate::tt::Subtree;
@@ -232,6 +232,8 @@ mod tests {
     use span::{SpanAnchor, SyntaxContextId, ROOT_ERASED_FILE_AST_ID};
     use syntax::{TextRange, TextSize};
 
+    use super::quote;
+
     const DUMMY: tt::Span = tt::Span {
         range: TextRange::empty(TextSize::new(0)),
         anchor: SpanAnchor {
diff --git a/crates/hir-expand/src/change.rs b/crates/hir-expand/src/change.rs
index 08491db372..1a3dd0e7dd 100644
--- a/crates/hir-expand/src/change.rs
+++ b/crates/hir-expand/src/change.rs
@@ -25,8 +25,7 @@ impl ChangeWithProcMacros {
 
     pub fn apply(self, db: &mut (impl ExpandDatabase + SourceDatabaseExt)) {
         self.source_change.apply(db);
-        if let Some(mut proc_macros) = self.proc_macros {
-            proc_macros.shrink_to_fit();
+        if let Some(proc_macros) = self.proc_macros {
             db.set_proc_macros_with_durability(Arc::new(proc_macros), Durability::HIGH);
         }
         if let Some(target_data_layouts) = self.target_data_layouts {
diff --git a/crates/hir-expand/src/db.rs b/crates/hir-expand/src/db.rs
index e78ab2460a..01a35660a9 100644
--- a/crates/hir-expand/src/db.rs
+++ b/crates/hir-expand/src/db.rs
@@ -11,8 +11,7 @@ use triomphe::Arc;
 
 use crate::{
     attrs::{collect_attrs, AttrId},
-    builtin_attr_macro::pseudo_derive_attr_expansion,
-    builtin_fn_macro::EagerExpander,
+    builtin::pseudo_derive_attr_expansion,
     cfg_process,
     declarative::DeclarativeMacroExpander,
     fixup::{self, SyntaxFixupUndoInfo},
@@ -20,9 +19,9 @@ use crate::{
     proc_macro::ProcMacros,
     span_map::{RealSpanMap, SpanMap, SpanMapRef},
     tt, AstId, BuiltinAttrExpander, BuiltinDeriveExpander, BuiltinFnLikeExpander,
-    CustomProcMacroExpander, EagerCallInfo, ExpandError, ExpandResult, ExpandTo, ExpansionSpanMap,
-    HirFileId, HirFileIdRepr, Lookup, MacroCallId, MacroCallKind, MacroCallLoc, MacroDefId,
-    MacroDefKind, MacroFileId,
+    CustomProcMacroExpander, EagerCallInfo, EagerExpander, ExpandError, ExpandResult, ExpandTo,
+    ExpansionSpanMap, HirFileId, HirFileIdRepr, Lookup, MacroCallId, MacroCallKind, MacroCallLoc,
+    MacroDefId, MacroDefKind, MacroFileId,
 };
 /// This is just to ensure the types of smart_macro_arg and macro_arg are the same
 type MacroArgResult = (Arc<tt::Subtree>, SyntaxFixupUndoInfo, Span);
@@ -260,39 +259,38 @@ pub fn expand_speculative(
 
     // Do the actual expansion, we need to directly expand the proc macro due to the attribute args
     // Otherwise the expand query will fetch the non speculative attribute args and pass those instead.
-    let mut speculative_expansion =
-        match loc.def.kind {
-            MacroDefKind::ProcMacro(ast, expander, _) => {
-                let span = db.proc_macro_span(ast);
-                tt.delimiter = tt::Delimiter::invisible_spanned(span);
-                expander.expand(
-                    db,
-                    loc.def.krate,
-                    loc.krate,
-                    &tt,
-                    attr_arg.as_ref(),
-                    span_with_def_site_ctxt(db, span, actual_macro_call),
-                    span_with_call_site_ctxt(db, span, actual_macro_call),
-                    span_with_mixed_site_ctxt(db, span, actual_macro_call),
-                )
-            }
-            MacroDefKind::BuiltInAttr(_, it) if it.is_derive() => {
-                pseudo_derive_attr_expansion(&tt, attr_arg.as_ref()?, span)
-            }
-            MacroDefKind::Declarative(it) => db
-                .decl_macro_expander(loc.krate, it)
-                .expand_unhygienic(db, tt, loc.def.krate, span, loc.def.edition),
-            MacroDefKind::BuiltIn(_, it) => {
-                it.expand(db, actual_macro_call, &tt, span).map_err(Into::into)
-            }
-            MacroDefKind::BuiltInDerive(_, it) => {
-                it.expand(db, actual_macro_call, &tt, span).map_err(Into::into)
-            }
-            MacroDefKind::BuiltInEager(_, it) => {
-                it.expand(db, actual_macro_call, &tt, span).map_err(Into::into)
-            }
-            MacroDefKind::BuiltInAttr(_, it) => it.expand(db, actual_macro_call, &tt, span),
-        };
+    let mut speculative_expansion = match loc.def.kind {
+        MacroDefKind::ProcMacro(ast, expander, _) => {
+            let span = db.proc_macro_span(ast);
+            tt.delimiter = tt::Delimiter::invisible_spanned(span);
+            expander.expand(
+                db,
+                loc.def.krate,
+                loc.krate,
+                &tt,
+                attr_arg.as_ref(),
+                span_with_def_site_ctxt(db, span, actual_macro_call),
+                span_with_call_site_ctxt(db, span, actual_macro_call),
+                span_with_mixed_site_ctxt(db, span, actual_macro_call),
+            )
+        }
+        MacroDefKind::BuiltInAttr(_, it) if it.is_derive() => {
+            pseudo_derive_attr_expansion(&tt, attr_arg.as_ref()?, span)
+        }
+        MacroDefKind::Declarative(it) => {
+            db.decl_macro_expander(loc.krate, it).expand_unhygienic(tt, span, loc.def.edition)
+        }
+        MacroDefKind::BuiltIn(_, it) => {
+            it.expand(db, actual_macro_call, &tt, span).map_err(Into::into)
+        }
+        MacroDefKind::BuiltInDerive(_, it) => {
+            it.expand(db, actual_macro_call, &tt, span).map_err(Into::into)
+        }
+        MacroDefKind::BuiltInEager(_, it) => {
+            it.expand(db, actual_macro_call, &tt, span).map_err(Into::into)
+        }
+        MacroDefKind::BuiltInAttr(_, it) => it.expand(db, actual_macro_call, &tt, span),
+    };
 
     let expand_to = loc.expand_to();
 
@@ -736,11 +734,14 @@ fn check_tt_count(tt: &tt::Subtree) -> Result<(), ExpandResult<()>> {
     if TOKEN_LIMIT.check(count).is_err() {
         Err(ExpandResult {
             value: (),
-            err: Some(ExpandError::other(format!(
-                "macro invocation exceeds token limit: produced {} tokens, limit is {}",
-                count,
-                TOKEN_LIMIT.inner(),
-            ))),
+            err: Some(ExpandError::other(
+                tt.delimiter.open,
+                format!(
+                    "macro invocation exceeds token limit: produced {} tokens, limit is {}",
+                    count,
+                    TOKEN_LIMIT.inner(),
+                ),
+            )),
         })
     } else {
         Ok(())
diff --git a/crates/hir-expand/src/declarative.rs b/crates/hir-expand/src/declarative.rs
index 85d7521dbc..48851af3fd 100644
--- a/crates/hir-expand/src/declarative.rs
+++ b/crates/hir-expand/src/declarative.rs
@@ -1,7 +1,6 @@
 //! Compiled declarative macro expanders (`macro_rules!`` and `macro`)
-use std::sync::OnceLock;
 
-use base_db::{CrateId, VersionReq};
+use base_db::CrateId;
 use intern::sym;
 use mbe::DocCommentDesugarMode;
 use span::{Edition, MacroCallId, Span, SyntaxContextId};
@@ -13,7 +12,7 @@ use crate::{
     attrs::RawAttrs,
     db::ExpandDatabase,
     hygiene::{apply_mark, Transparency},
-    tt, AstId, ExpandError, ExpandResult, Lookup,
+    tt, AstId, ExpandError, ExpandErrorKind, ExpandResult, Lookup,
 };
 
 /// Old-style `macro_rules` or the new macros 2.0
@@ -23,9 +22,6 @@ pub struct DeclarativeMacroExpander {
     pub transparency: Transparency,
 }
 
-// FIXME: Remove this once we drop support for 1.76
-static REQUIREMENT: OnceLock<VersionReq> = OnceLock::new();
-
 impl DeclarativeMacroExpander {
     pub fn expand(
         &self,
@@ -35,29 +31,16 @@ impl DeclarativeMacroExpander {
         span: Span,
     ) -> ExpandResult<(tt::Subtree, Option<u32>)> {
         let loc = db.lookup_intern_macro_call(call_id);
-        let toolchain = db.toolchain(loc.def.krate);
-        let new_meta_vars = toolchain.as_ref().map_or(false, |version| {
-            REQUIREMENT.get_or_init(|| VersionReq::parse(">=1.76").unwrap()).matches(
-                &base_db::Version {
-                    pre: base_db::Prerelease::EMPTY,
-                    build: base_db::BuildMetadata::EMPTY,
-                    major: version.major,
-                    minor: version.minor,
-                    patch: version.patch,
-                },
-            )
-        });
         match self.mac.err() {
             Some(_) => ExpandResult::new(
                 (tt::Subtree::empty(tt::DelimSpan { open: span, close: span }), None),
-                ExpandError::MacroDefinition,
+                ExpandError::new(span, ExpandErrorKind::MacroDefinition),
             ),
             None => self
                 .mac
                 .expand(
                     &tt,
                     |s| s.ctx = apply_mark(db, s.ctx, call_id, self.transparency),
-                    new_meta_vars,
                     span,
                     loc.def.edition,
                 )
@@ -67,32 +50,18 @@ impl DeclarativeMacroExpander {
 
     pub fn expand_unhygienic(
         &self,
-        db: &dyn ExpandDatabase,
         tt: tt::Subtree,
-        krate: CrateId,
         call_site: Span,
         def_site_edition: Edition,
     ) -> ExpandResult<tt::Subtree> {
-        let toolchain = db.toolchain(krate);
-        let new_meta_vars = toolchain.as_ref().map_or(false, |version| {
-            REQUIREMENT.get_or_init(|| VersionReq::parse(">=1.76").unwrap()).matches(
-                &base_db::Version {
-                    pre: base_db::Prerelease::EMPTY,
-                    build: base_db::BuildMetadata::EMPTY,
-                    major: version.major,
-                    minor: version.minor,
-                    patch: version.patch,
-                },
-            )
-        });
         match self.mac.err() {
             Some(_) => ExpandResult::new(
                 tt::Subtree::empty(tt::DelimSpan { open: call_site, close: call_site }),
-                ExpandError::MacroDefinition,
+                ExpandError::new(call_site, ExpandErrorKind::MacroDefinition),
             ),
             None => self
                 .mac
-                .expand(&tt, |_| (), new_meta_vars, call_site, def_site_edition)
+                .expand(&tt, |_| (), call_site, def_site_edition)
                 .map(TupleExt::head)
                 .map_err(Into::into),
         }
diff --git a/crates/hir-expand/src/eager.rs b/crates/hir-expand/src/eager.rs
index 6a4e235b53..5385b44532 100644
--- a/crates/hir-expand/src/eager.rs
+++ b/crates/hir-expand/src/eager.rs
@@ -176,14 +176,19 @@ fn eager_macro_recur(
             Some(path) => match macro_resolver(&path) {
                 Some(def) => def,
                 None => {
-                    error =
-                        Some(ExpandError::other(format!("unresolved macro {}", path.display(db))));
+                    error = Some(ExpandError::other(
+                        span_map.span_at(call.syntax().text_range().start()),
+                        format!("unresolved macro {}", path.display(db)),
+                    ));
                     offset += call.syntax().text_range().len();
                     continue;
                 }
             },
             None => {
-                error = Some(ExpandError::other("malformed macro invocation"));
+                error = Some(ExpandError::other(
+                    span_map.span_at(call.syntax().text_range().start()),
+                    "malformed macro invocation",
+                ));
                 offset += call.syntax().text_range().len();
                 continue;
             }
diff --git a/crates/hir-expand/src/lib.rs b/crates/hir-expand/src/lib.rs
index c262fcae47..18da77d6ca 100644
--- a/crates/hir-expand/src/lib.rs
+++ b/crates/hir-expand/src/lib.rs
@@ -6,9 +6,7 @@
 #![cfg_attr(feature = "in-rust-tree", feature(rustc_private))]
 
 pub mod attrs;
-pub mod builtin_attr_macro;
-pub mod builtin_derive_macro;
-pub mod builtin_fn_macro;
+pub mod builtin;
 pub mod change;
 pub mod db;
 pub mod declarative;
@@ -19,7 +17,6 @@ pub mod inert_attr_macro;
 pub mod mod_path;
 pub mod name;
 pub mod proc_macro;
-pub mod quote;
 pub mod span_map;
 
 mod cfg_process;
@@ -29,7 +26,7 @@ use attrs::collect_attrs;
 use rustc_hash::FxHashMap;
 use triomphe::Arc;
 
-use std::{fmt, hash::Hash};
+use std::hash::Hash;
 
 use base_db::{salsa::InternValueTrivial, CrateId};
 use either::Either;
@@ -44,9 +41,10 @@ use syntax::{
 
 use crate::{
     attrs::AttrId,
-    builtin_attr_macro::BuiltinAttrExpander,
-    builtin_derive_macro::BuiltinDeriveExpander,
-    builtin_fn_macro::{BuiltinFnLikeExpander, EagerExpander},
+    builtin::{
+        include_input_to_file_id, BuiltinAttrExpander, BuiltinDeriveExpander,
+        BuiltinFnLikeExpander, EagerExpander,
+    },
     db::ExpandDatabase,
     mod_path::ModPath,
     proc_macro::{CustomProcMacroExpander, ProcMacroKind},
@@ -126,46 +124,79 @@ impl_intern_lookup!(
 pub type ExpandResult<T> = ValueResult<T, ExpandError>;
 
 #[derive(Debug, PartialEq, Eq, Clone, Hash)]
-pub enum ExpandError {
-    UnresolvedProcMacro(CrateId),
-    /// The macro expansion is disabled.
-    MacroDisabled,
-    MacroDefinition,
-    Mbe(mbe::ExpandError),
-    RecursionOverflow,
-    Other(Arc<Box<str>>),
-    ProcMacroPanic(Arc<Box<str>>),
+pub struct ExpandError {
+    inner: Arc<(ExpandErrorKind, Span)>,
 }
 
 impl ExpandError {
-    pub fn other(msg: impl Into<Box<str>>) -> Self {
-        ExpandError::Other(Arc::new(msg.into()))
+    pub fn new(span: Span, kind: ExpandErrorKind) -> Self {
+        ExpandError { inner: Arc::new((kind, span)) }
+    }
+    pub fn other(span: Span, msg: impl Into<Box<str>>) -> Self {
+        ExpandError { inner: Arc::new((ExpandErrorKind::Other(msg.into()), span)) }
+    }
+    pub fn kind(&self) -> &ExpandErrorKind {
+        &self.inner.0
+    }
+    pub fn span(&self) -> Span {
+        self.inner.1
+    }
+}
+
+#[derive(Debug, PartialEq, Eq, Clone, Hash)]
+pub enum ExpandErrorKind {
+    /// Attribute macro expansion is disabled.
+    ProcMacroAttrExpansionDisabled,
+    MissingProcMacroExpander(CrateId),
+    /// The macro for this call is disabled.
+    MacroDisabled,
+    /// The macro definition has errors.
+    MacroDefinition,
+    Mbe(mbe::ExpandErrorKind),
+    RecursionOverflow,
+    Other(Box<str>),
+    ProcMacroPanic(Box<str>),
+}
+
+impl ExpandError {
+    pub fn render_to_string(&self, db: &dyn ExpandDatabase) -> (String, bool) {
+        self.inner.0.render_to_string(db)
+    }
+}
+
+impl ExpandErrorKind {
+    pub fn render_to_string(&self, db: &dyn ExpandDatabase) -> (String, bool) {
+        match self {
+            ExpandErrorKind::ProcMacroAttrExpansionDisabled => {
+                ("procedural attribute macro expansion is disabled".to_owned(), false)
+            }
+            ExpandErrorKind::MacroDisabled => {
+                ("proc-macro is explicitly disabled".to_owned(), false)
+            }
+            &ExpandErrorKind::MissingProcMacroExpander(def_crate) => {
+                match db.proc_macros().get_error_for_crate(def_crate) {
+                    Some((e, hard_err)) => (e.to_owned(), hard_err),
+                    None => ("missing expander".to_owned(), true),
+                }
+            }
+            ExpandErrorKind::MacroDefinition => {
+                ("macro definition has parse errors".to_owned(), true)
+            }
+            ExpandErrorKind::Mbe(e) => (e.to_string(), true),
+            ExpandErrorKind::RecursionOverflow => {
+                ("overflow expanding the original macro".to_owned(), true)
+            }
+            ExpandErrorKind::Other(e) => ((**e).to_owned(), true),
+            ExpandErrorKind::ProcMacroPanic(e) => ((**e).to_owned(), true),
+        }
     }
 }
 
 impl From<mbe::ExpandError> for ExpandError {
     fn from(mbe: mbe::ExpandError) -> Self {
-        Self::Mbe(mbe)
+        ExpandError { inner: Arc::new((ExpandErrorKind::Mbe(mbe.inner.1.clone()), mbe.inner.0)) }
     }
 }
-
-impl fmt::Display for ExpandError {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            ExpandError::UnresolvedProcMacro(_) => f.write_str("unresolved proc-macro"),
-            ExpandError::Mbe(it) => it.fmt(f),
-            ExpandError::RecursionOverflow => f.write_str("overflow expanding the original macro"),
-            ExpandError::ProcMacroPanic(it) => {
-                f.write_str("proc-macro panicked: ")?;
-                f.write_str(it)
-            }
-            ExpandError::Other(it) => f.write_str(it),
-            ExpandError::MacroDisabled => f.write_str("macro disabled"),
-            ExpandError::MacroDefinition => f.write_str("macro definition has parse errors"),
-        }
-    }
-}
-
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct MacroCallLoc {
     pub def: MacroDefId,
@@ -277,11 +308,9 @@ impl HirFileIdExt for HirFileId {
                     let loc = db.lookup_intern_macro_call(file.macro_call_id);
                     if loc.def.is_include() {
                         if let MacroCallKind::FnLike { eager: Some(eager), .. } = &loc.kind {
-                            if let Ok(it) = builtin_fn_macro::include_input_to_file_id(
-                                db,
-                                file.macro_call_id,
-                                &eager.arg,
-                            ) {
+                            if let Ok(it) =
+                                include_input_to_file_id(db, file.macro_call_id, &eager.arg)
+                            {
                                 break it;
                             }
                         }
@@ -572,9 +601,7 @@ impl MacroCallLoc {
     ) -> Option<EditionedFileId> {
         if self.def.is_include() {
             if let MacroCallKind::FnLike { eager: Some(eager), .. } = &self.kind {
-                if let Ok(it) =
-                    builtin_fn_macro::include_input_to_file_id(db, macro_call_id, &eager.arg)
-                {
+                if let Ok(it) = include_input_to_file_id(db, macro_call_id, &eager.arg) {
                     return Some(it);
                 }
             }
diff --git a/crates/hir-expand/src/proc_macro.rs b/crates/hir-expand/src/proc_macro.rs
index 39599bfe02..26bb3a3edd 100644
--- a/crates/hir-expand/src/proc_macro.rs
+++ b/crates/hir-expand/src/proc_macro.rs
@@ -7,19 +7,8 @@ use base_db::{CrateId, Env};
 use intern::Symbol;
 use rustc_hash::FxHashMap;
 use span::Span;
-use stdx::never;
-use triomphe::Arc;
 
-use crate::{db::ExpandDatabase, tt, ExpandError, ExpandResult};
-
-#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
-pub struct ProcMacroId(u32);
-
-impl ProcMacroId {
-    pub fn new(u32: u32) -> Self {
-        ProcMacroId(u32)
-    }
-}
+use crate::{db::ExpandDatabase, tt, ExpandError, ExpandErrorKind, ExpandResult};
 
 #[derive(Copy, Clone, Eq, PartialEq, Debug, Hash)]
 pub enum ProcMacroKind {
@@ -28,7 +17,10 @@ pub enum ProcMacroKind {
     Attr,
 }
 
+/// A proc-macro expander implementation.
 pub trait ProcMacroExpander: fmt::Debug + Send + Sync + RefUnwindSafe {
+    /// Run the expander with the given input subtree, optional attribute input subtree (for
+    /// [`ProcMacroKind::Attr`]), environment variables, and span information.
     fn expand(
         &self,
         subtree: &tt::Subtree,
@@ -42,57 +34,165 @@ pub trait ProcMacroExpander: fmt::Debug + Send + Sync + RefUnwindSafe {
 
 #[derive(Debug)]
 pub enum ProcMacroExpansionError {
+    /// The proc-macro panicked.
     Panic(String),
-    /// Things like "proc macro server was killed by OOM".
+    /// The server itself errored out.
     System(String),
 }
 
-pub type ProcMacroLoadResult = Result<Vec<ProcMacro>, String>;
+pub type ProcMacroLoadResult = Result<Vec<ProcMacro>, (String, bool)>;
+type StoredProcMacroLoadResult = Result<Box<[ProcMacro]>, (Box<str>, bool)>;
 
-pub type ProcMacros = FxHashMap<CrateId, ProcMacroLoadResult>;
+#[derive(Default, Debug)]
+pub struct ProcMacrosBuilder(FxHashMap<CrateId, StoredProcMacroLoadResult>);
+impl ProcMacrosBuilder {
+    pub fn insert(&mut self, proc_macros_crate: CrateId, proc_macro: ProcMacroLoadResult) {
+        self.0.insert(
+            proc_macros_crate,
+            match proc_macro {
+                Ok(it) => Ok(it.into_boxed_slice()),
+                Err((e, hard_err)) => Err((e.into_boxed_str(), hard_err)),
+            },
+        );
+    }
+    pub fn build(mut self) -> ProcMacros {
+        self.0.shrink_to_fit();
+        ProcMacros(self.0)
+    }
+}
 
+#[derive(Default, Debug)]
+pub struct ProcMacros(FxHashMap<CrateId, StoredProcMacroLoadResult>);
+
+impl FromIterator<(CrateId, ProcMacroLoadResult)> for ProcMacros {
+    fn from_iter<T: IntoIterator<Item = (CrateId, ProcMacroLoadResult)>>(iter: T) -> Self {
+        let mut builder = ProcMacrosBuilder::default();
+        for (k, v) in iter {
+            builder.insert(k, v);
+        }
+        builder.build()
+    }
+}
+
+impl ProcMacros {
+    fn get(&self, krate: CrateId, idx: u32, err_span: Span) -> Result<&ProcMacro, ExpandError> {
+        let proc_macros = match self.0.get(&krate) {
+            Some(Ok(proc_macros)) => proc_macros,
+            Some(Err(_)) | None => {
+                return Err(ExpandError::other(
+                    err_span,
+                    "internal error: no proc macros for crate",
+                ));
+            }
+        };
+        proc_macros.get(idx as usize).ok_or_else(|| {
+                ExpandError::other(err_span,
+                    format!(
+                        "internal error: proc-macro index out of bounds: the length is {} but the index is {}",
+                        proc_macros.len(),
+                        idx
+                    )
+                )
+            }
+        )
+    }
+
+    pub fn get_error_for_crate(&self, krate: CrateId) -> Option<(&str, bool)> {
+        self.0.get(&krate).and_then(|it| it.as_ref().err()).map(|(e, hard_err)| (&**e, *hard_err))
+    }
+
+    /// Fetch the [`CustomProcMacroExpander`]s and their corresponding names for the given crate.
+    pub fn for_crate(
+        &self,
+        krate: CrateId,
+        def_site_ctx: span::SyntaxContextId,
+    ) -> Option<Box<[(crate::name::Name, CustomProcMacroExpander, bool)]>> {
+        match self.0.get(&krate) {
+            Some(Ok(proc_macros)) => Some({
+                proc_macros
+                    .iter()
+                    .enumerate()
+                    .map(|(idx, it)| {
+                        let name = crate::name::Name::new_symbol(it.name.clone(), def_site_ctx);
+                        (name, CustomProcMacroExpander::new(idx as u32), it.disabled)
+                    })
+                    .collect()
+            }),
+            _ => None,
+        }
+    }
+}
+
+/// A loaded proc-macro.
 #[derive(Debug, Clone)]
 pub struct ProcMacro {
+    /// The name of the proc macro.
     pub name: Symbol,
     pub kind: ProcMacroKind,
+    /// The expander handle for this proc macro.
     pub expander: sync::Arc<dyn ProcMacroExpander>,
+    /// Whether this proc-macro is disabled for early name resolution. Notably, the
+    /// [`Self::expander`] is still usable.
     pub disabled: bool,
 }
 
+/// A custom proc-macro expander handle. This handle together with its crate resolves to a [`ProcMacro`]
 #[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)]
 pub struct CustomProcMacroExpander {
-    proc_macro_id: ProcMacroId,
+    proc_macro_id: u32,
 }
 
 impl CustomProcMacroExpander {
-    const DUMMY_ID: u32 = !0;
+    const MISSING_EXPANDER: u32 = !0;
     const DISABLED_ID: u32 = !1;
+    const PROC_MACRO_ATTR_DISABLED: u32 = !2;
 
-    pub fn new(proc_macro_id: ProcMacroId) -> Self {
-        assert_ne!(proc_macro_id.0, Self::DUMMY_ID);
-        assert_ne!(proc_macro_id.0, Self::DISABLED_ID);
+    pub fn new(proc_macro_id: u32) -> Self {
+        assert_ne!(proc_macro_id, Self::MISSING_EXPANDER);
+        assert_ne!(proc_macro_id, Self::DISABLED_ID);
+        assert_ne!(proc_macro_id, Self::PROC_MACRO_ATTR_DISABLED);
         Self { proc_macro_id }
     }
 
-    /// A dummy expander that always errors. This is used for proc-macros that are missing, usually
-    /// due to them not being built yet.
-    pub const fn dummy() -> Self {
-        Self { proc_macro_id: ProcMacroId(Self::DUMMY_ID) }
-    }
-
-    /// The macro was not yet resolved.
-    pub const fn is_dummy(&self) -> bool {
-        self.proc_macro_id.0 == Self::DUMMY_ID
+    /// An expander that always errors due to the actual proc-macro expander missing.
+    pub const fn missing_expander() -> Self {
+        Self { proc_macro_id: Self::MISSING_EXPANDER }
     }
 
     /// A dummy expander that always errors. This expander is used for macros that have been disabled.
     pub const fn disabled() -> Self {
-        Self { proc_macro_id: ProcMacroId(Self::DISABLED_ID) }
+        Self { proc_macro_id: Self::DISABLED_ID }
+    }
+
+    /// A dummy expander that always errors. This expander is used for attribute macros when
+    /// proc-macro attribute expansion is disabled.
+    pub const fn disabled_proc_attr() -> Self {
+        Self { proc_macro_id: Self::PROC_MACRO_ATTR_DISABLED }
+    }
+
+    /// The macro-expander is missing or has yet to be build.
+    pub const fn is_missing(&self) -> bool {
+        self.proc_macro_id == Self::MISSING_EXPANDER
     }
 
     /// The macro is explicitly disabled and cannot be expanded.
     pub const fn is_disabled(&self) -> bool {
-        self.proc_macro_id.0 == Self::DISABLED_ID
+        self.proc_macro_id == Self::DISABLED_ID
+    }
+
+    /// The macro is explicitly disabled due to proc-macro attribute expansion being disabled.
+    pub const fn is_disabled_proc_attr(&self) -> bool {
+        self.proc_macro_id == Self::PROC_MACRO_ATTR_DISABLED
+    }
+
+    /// The macro is explicitly disabled due to proc-macro attribute expansion being disabled.
+    pub fn as_expand_error(&self, def_crate: CrateId) -> Option<ExpandErrorKind> {
+        match self.proc_macro_id {
+            Self::PROC_MACRO_ATTR_DISABLED => Some(ExpandErrorKind::ProcMacroAttrExpansionDisabled),
+            Self::DISABLED_ID => Some(ExpandErrorKind::MacroDisabled),
+            Self::MISSING_EXPANDER => Some(ExpandErrorKind::MissingProcMacroExpander(def_crate)),
+            _ => None,
+        }
     }
 
     pub fn expand(
@@ -107,38 +207,27 @@ impl CustomProcMacroExpander {
         mixed_site: Span,
     ) -> ExpandResult<tt::Subtree> {
         match self.proc_macro_id {
-            ProcMacroId(Self::DUMMY_ID) => ExpandResult::new(
+            Self::PROC_MACRO_ATTR_DISABLED => ExpandResult::new(
                 tt::Subtree::empty(tt::DelimSpan { open: call_site, close: call_site }),
-                ExpandError::UnresolvedProcMacro(def_crate),
+                ExpandError::new(call_site, ExpandErrorKind::ProcMacroAttrExpansionDisabled),
             ),
-            ProcMacroId(Self::DISABLED_ID) => ExpandResult::new(
+            Self::MISSING_EXPANDER => ExpandResult::new(
                 tt::Subtree::empty(tt::DelimSpan { open: call_site, close: call_site }),
-                ExpandError::MacroDisabled,
+                ExpandError::new(call_site, ExpandErrorKind::MissingProcMacroExpander(def_crate)),
             ),
-            ProcMacroId(id) => {
+            Self::DISABLED_ID => ExpandResult::new(
+                tt::Subtree::empty(tt::DelimSpan { open: call_site, close: call_site }),
+                ExpandError::new(call_site, ExpandErrorKind::MacroDisabled),
+            ),
+            id => {
                 let proc_macros = db.proc_macros();
-                let proc_macros = match proc_macros.get(&def_crate) {
-                    Some(Ok(proc_macros)) => proc_macros,
-                    Some(Err(_)) | None => {
-                        never!("Non-dummy expander even though there are no proc macros");
+                let proc_macro = match proc_macros.get(def_crate, id, call_site) {
+                    Ok(proc_macro) => proc_macro,
+                    Err(e) => {
                         return ExpandResult::new(
                             tt::Subtree::empty(tt::DelimSpan { open: call_site, close: call_site }),
-                            ExpandError::other("Internal error"),
-                        );
-                    }
-                };
-                let proc_macro = match proc_macros.get(id as usize) {
-                    Some(proc_macro) => proc_macro,
-                    None => {
-                        never!(
-                            "Proc macro index out of bounds: the length is {} but the index is {}",
-                            proc_macros.len(),
-                            id
-                        );
-                        return ExpandResult::new(
-                            tt::Subtree::empty(tt::DelimSpan { open: call_site, close: call_site }),
-                            ExpandError::other("Internal error: proc-macro index out of bounds"),
-                        );
+                            e,
+                        )
                     }
                 };
 
@@ -153,12 +242,18 @@ impl CustomProcMacroExpander {
                         ProcMacroExpansionError::System(text)
                             if proc_macro.kind == ProcMacroKind::Attr =>
                         {
-                            ExpandResult { value: tt.clone(), err: Some(ExpandError::other(text)) }
+                            ExpandResult {
+                                value: tt.clone(),
+                                err: Some(ExpandError::other(call_site, text)),
+                            }
                         }
                         ProcMacroExpansionError::System(text)
                         | ProcMacroExpansionError::Panic(text) => ExpandResult::new(
                             tt::Subtree::empty(tt::DelimSpan { open: call_site, close: call_site }),
-                            ExpandError::ProcMacroPanic(Arc::new(text.into_boxed_str())),
+                            ExpandError::new(
+                                call_site,
+                                ExpandErrorKind::ProcMacroPanic(text.into_boxed_str()),
+                            ),
                         ),
                     },
                 }
diff --git a/crates/hir/src/diagnostics.rs b/crates/hir/src/diagnostics.rs
index 72272934ab..4bb8c140a1 100644
--- a/crates/hir/src/diagnostics.rs
+++ b/crates/hir/src/diagnostics.rs
@@ -6,7 +6,6 @@
 pub use hir_ty::diagnostics::{CaseType, IncorrectCase};
 use hir_ty::{db::HirDatabase, diagnostics::BodyValidationDiagnostic, InferenceDiagnostic};
 
-use base_db::CrateId;
 use cfg::{CfgExpr, CfgOptions};
 use either::Either;
 pub use hir_def::VariantId;
@@ -15,7 +14,7 @@ use hir_expand::{name::Name, HirFileId, InFile};
 use syntax::{ast, AstPtr, SyntaxError, SyntaxNodePtr, TextRange};
 use triomphe::Arc;
 
-use crate::{AssocItem, Field, Local, MacroKind, Trait, Type};
+use crate::{AssocItem, Field, Local, Trait, Type};
 
 macro_rules! diagnostics {
     ($($diag:ident,)*) => {
@@ -90,7 +89,6 @@ diagnostics![
     UnresolvedMethodCall,
     UnresolvedModule,
     UnresolvedIdent,
-    UnresolvedProcMacro,
     UnusedMut,
     UnusedVariable,
 ];
@@ -150,23 +148,12 @@ pub struct InactiveCode {
     pub opts: CfgOptions,
 }
 
-#[derive(Debug, Clone, Eq, PartialEq)]
-pub struct UnresolvedProcMacro {
-    pub node: InFile<SyntaxNodePtr>,
-    /// If the diagnostic can be pinpointed more accurately than via `node`, this is the `TextRange`
-    /// to use instead.
-    pub precise_location: Option<TextRange>,
-    pub macro_name: Option<String>,
-    pub kind: MacroKind,
-    /// The crate id of the proc-macro this macro belongs to, or `None` if the proc-macro can't be found.
-    pub krate: CrateId,
-}
-
 #[derive(Debug, Clone, Eq, PartialEq)]
 pub struct MacroError {
     pub node: InFile<SyntaxNodePtr>,
     pub precise_location: Option<TextRange>,
     pub message: String,
+    pub error: bool,
 }
 
 #[derive(Debug, Clone, Eq, PartialEq)]
diff --git a/crates/hir/src/lib.rs b/crates/hir/src/lib.rs
index 70f4a632fb..266ef2a55c 100644
--- a/crates/hir/src/lib.rs
+++ b/crates/hir/src/lib.rs
@@ -137,7 +137,7 @@ pub use {
         hygiene::{marks_rev, SyntaxContextExt},
         inert_attr_macro::AttributeTemplate,
         name::Name,
-        proc_macro::ProcMacros,
+        proc_macro::{ProcMacros, ProcMacrosBuilder},
         tt, ExpandResult, HirFileId, HirFileIdExt, MacroFileId, MacroFileIdExt,
     },
     hir_ty::{
@@ -833,19 +833,27 @@ fn macro_call_diagnostics(
     let ValueResult { value: parse_errors, err } = &*e;
     if let Some(err) = err {
         let loc = db.lookup_intern_macro_call(macro_call_id);
-        let (node, precise_location, macro_name, kind) = precise_macro_call_location(&loc.kind, db);
-        let diag = match err {
-            &hir_expand::ExpandError::UnresolvedProcMacro(krate) => {
-                UnresolvedProcMacro { node, precise_location, macro_name, kind, krate }.into()
-            }
-            err => MacroError { node, precise_location, message: err.to_string() }.into(),
+        let file_id = loc.kind.file_id();
+        let node =
+            InFile::new(file_id, db.ast_id_map(file_id).get_erased(loc.kind.erased_ast_id()));
+        let (message, error) = err.render_to_string(db.upcast());
+        let precise_location = if err.span().anchor.file_id == file_id {
+            Some(
+                err.span().range
+                    + db.ast_id_map(err.span().anchor.file_id.into())
+                        .get_erased(err.span().anchor.ast_id)
+                        .text_range()
+                        .start(),
+            )
+        } else {
+            None
         };
-        acc.push(diag);
+        acc.push(MacroError { node, precise_location, message, error }.into());
     }
 
     if !parse_errors.is_empty() {
         let loc = db.lookup_intern_macro_call(macro_call_id);
-        let (node, precise_location, _, _) = precise_macro_call_location(&loc.kind, db);
+        let (node, precise_location) = precise_macro_call_location(&loc.kind, db);
         acc.push(
             MacroExpansionParseError { node, precise_location, errors: parse_errors.clone() }
                 .into(),
@@ -895,6 +903,19 @@ fn emit_def_diagnostic_(
             acc.push(UnresolvedExternCrate { decl: InFile::new(ast.file_id, item) }.into());
         }
 
+        DefDiagnosticKind::MacroError { ast, path, err } => {
+            let item = ast.to_ptr(db.upcast());
+            let (message, error) = err.render_to_string(db.upcast());
+            acc.push(
+                MacroError {
+                    node: InFile::new(ast.file_id, item.syntax_node_ptr()),
+                    precise_location: None,
+                    message: format!("{}: {message}", path.display(db.upcast())),
+                    error,
+                }
+                .into(),
+            )
+        }
         DefDiagnosticKind::UnresolvedImport { id, index } => {
             let file_id = id.file_id();
             let item_tree = id.item_tree(db.upcast());
@@ -991,15 +1012,8 @@ fn emit_def_diagnostic_(
                 Some(())
             })();
         }
-        DefDiagnosticKind::UnresolvedProcMacro { ast, krate } => {
-            let (node, precise_location, macro_name, kind) = precise_macro_call_location(ast, db);
-            acc.push(
-                UnresolvedProcMacro { node, precise_location, macro_name, kind, krate: *krate }
-                    .into(),
-            );
-        }
         DefDiagnosticKind::UnresolvedMacroCall { ast, path } => {
-            let (node, precise_location, _, _) = precise_macro_call_location(ast, db);
+            let (node, precise_location) = precise_macro_call_location(ast, db);
             acc.push(
                 UnresolvedMacroCall {
                     macro_call: node,
@@ -1068,7 +1082,7 @@ fn emit_def_diagnostic_(
 fn precise_macro_call_location(
     ast: &MacroCallKind,
     db: &dyn HirDatabase,
-) -> (InFile<SyntaxNodePtr>, Option<TextRange>, Option<String>, MacroKind) {
+) -> (InFile<SyntaxNodePtr>, Option<TextRange>) {
     // FIXME: maybe we actually want slightly different ranges for the different macro diagnostics
     // - e.g. the full attribute for macro errors, but only the name for name resolution
     match ast {
@@ -1080,8 +1094,6 @@ fn precise_macro_call_location(
                     .and_then(|it| it.segment())
                     .and_then(|it| it.name_ref())
                     .map(|it| it.syntax().text_range()),
-                node.path().and_then(|it| it.segment()).map(|it| it.to_string()),
-                MacroKind::ProcMacro,
             )
         }
         MacroCallKind::Derive { ast_id, derive_attr_index, derive_index, .. } => {
@@ -1110,8 +1122,6 @@ fn precise_macro_call_location(
             (
                 ast_id.with_value(SyntaxNodePtr::from(AstPtr::new(&node))),
                 token.as_ref().map(|tok| tok.text_range()),
-                token.as_ref().map(ToString::to_string),
-                MacroKind::Derive,
             )
         }
         MacroCallKind::Attr { ast_id, invoc_attr_index, .. } => {
@@ -1126,12 +1136,6 @@ fn precise_macro_call_location(
             (
                 ast_id.with_value(SyntaxNodePtr::from(AstPtr::new(&attr))),
                 Some(attr.syntax().text_range()),
-                attr.path()
-                    .and_then(|path| path.segment())
-                    .and_then(|seg| seg.name_ref())
-                    .as_ref()
-                    .map(ToString::to_string),
-                MacroKind::Attr,
             )
         }
     }
@@ -1795,20 +1799,28 @@ impl DefWithBody {
                 BodyDiagnostic::InactiveCode { node, cfg, opts } => {
                     InactiveCode { node: *node, cfg: cfg.clone(), opts: opts.clone() }.into()
                 }
-                BodyDiagnostic::MacroError { node, message } => MacroError {
-                    node: (*node).map(|it| it.into()),
-                    precise_location: None,
-                    message: message.to_string(),
+                BodyDiagnostic::MacroError { node, err } => {
+                    let (message, error) = err.render_to_string(db.upcast());
+
+                    let precise_location = if err.span().anchor.file_id == node.file_id {
+                        Some(
+                            err.span().range
+                                + db.ast_id_map(err.span().anchor.file_id.into())
+                                    .get_erased(err.span().anchor.ast_id)
+                                    .text_range()
+                                    .start(),
+                        )
+                    } else {
+                        None
+                    };
+                    MacroError {
+                        node: (*node).map(|it| it.into()),
+                        precise_location,
+                        message,
+                        error,
+                    }
+                    .into()
                 }
-                .into(),
-                BodyDiagnostic::UnresolvedProcMacro { node, krate } => UnresolvedProcMacro {
-                    node: (*node).map(|it| it.into()),
-                    precise_location: None,
-                    macro_name: None,
-                    kind: MacroKind::ProcMacro,
-                    krate: *krate,
-                }
-                .into(),
                 BodyDiagnostic::UnresolvedMacroCall { node, path } => UnresolvedMacroCall {
                     macro_call: (*node).map(|ast_ptr| ast_ptr.into()),
                     precise_location: None,
diff --git a/crates/hir/src/semantics.rs b/crates/hir/src/semantics.rs
index c053a659b3..29f98972dc 100644
--- a/crates/hir/src/semantics.rs
+++ b/crates/hir/src/semantics.rs
@@ -19,7 +19,7 @@ use hir_def::{
 };
 use hir_expand::{
     attrs::collect_attrs,
-    builtin_fn_macro::{BuiltinFnLikeExpander, EagerExpander},
+    builtin::{BuiltinFnLikeExpander, EagerExpander},
     db::ExpandDatabase,
     files::InRealFile,
     name::AsName,
diff --git a/crates/ide-diagnostics/src/handlers/macro_error.rs b/crates/ide-diagnostics/src/handlers/macro_error.rs
index 2cd6a71c00..e59b63f288 100644
--- a/crates/ide-diagnostics/src/handlers/macro_error.rs
+++ b/crates/ide-diagnostics/src/handlers/macro_error.rs
@@ -7,7 +7,10 @@ pub(crate) fn macro_error(ctx: &DiagnosticsContext<'_>, d: &hir::MacroError) ->
     // Use more accurate position if available.
     let display_range = ctx.resolve_precise_location(&d.node, d.precise_location);
     Diagnostic::new(
-        DiagnosticCode::Ra("macro-error", Severity::Error),
+        DiagnosticCode::Ra(
+            "macro-error",
+            if d.error { Severity::Error } else { Severity::WeakWarning },
+        ),
         d.message.clone(),
         display_range,
     )
@@ -45,7 +48,7 @@ macro_rules! include { () => {} }
 macro_rules! compile_error { () => {} }
 
   include!("doesntexist");
-//^^^^^^^ error: failed to load file `doesntexist`
+         //^^^^^^^^^^^^^ error: failed to load file `doesntexist`
 
   compile_error!("compile_error macro works");
 //^^^^^^^^^^^^^ error: compile_error macro works
@@ -125,7 +128,7 @@ macro_rules! env { () => {} }
 macro_rules! concat { () => {} }
 
   include!(concat!(env!("OUT_DIR"), "/out.rs"));
-//^^^^^^^ error: `OUT_DIR` not set, enable "build scripts" to fix
+                      //^^^^^^^^^ error: `OUT_DIR` not set, enable "build scripts" to fix
 "#,
         );
     }
@@ -160,20 +163,25 @@ macro_rules! include {}
 
 #[rustc_builtin_macro]
 macro_rules! compile_error {}
+#[rustc_builtin_macro]
+macro_rules! concat {}
 
 fn main() {
     // Test a handful of built-in (eager) macros:
 
     include!(invalid);
-  //^^^^^^^ error: could not convert tokens
+           //^^^^^^^ error: expected string literal
     include!("does not exist");
-  //^^^^^^^ error: failed to load file `does not exist`
+           //^^^^^^^^^^^^^^^^ error: failed to load file `does not exist`
+
+    include!(concat!("does ", "not ", "exist"));
+                  //^^^^^^^^^^^^^^^^^^^^^^^^^^ error: failed to load file `does not exist`
 
     env!(invalid);
-  //^^^ error: could not convert tokens
+       //^^^^^^^ error: expected string literal
 
     env!("OUT_DIR");
-  //^^^ error: `OUT_DIR` not set, enable "build scripts" to fix
+       //^^^^^^^^^ error: `OUT_DIR` not set, enable "build scripts" to fix
 
     compile_error!("compile_error works");
   //^^^^^^^^^^^^^ error: compile_error works
@@ -198,7 +206,7 @@ fn f() {
     m!();
 
     m!(hi);
-  //^ error: leftover tokens
+    //^ error: leftover tokens
 }
       "#,
         );
diff --git a/crates/ide-diagnostics/src/handlers/unresolved_proc_macro.rs b/crates/ide-diagnostics/src/handlers/unresolved_proc_macro.rs
deleted file mode 100644
index 7ea50c496f..0000000000
--- a/crates/ide-diagnostics/src/handlers/unresolved_proc_macro.rs
+++ /dev/null
@@ -1,45 +0,0 @@
-use hir::db::DefDatabase;
-
-use crate::{Diagnostic, DiagnosticCode, DiagnosticsContext, Severity};
-
-// Diagnostic: unresolved-proc-macro
-//
-// This diagnostic is shown when a procedural macro can not be found. This usually means that
-// procedural macro support is simply disabled (and hence is only a weak hint instead of an error),
-// but can also indicate project setup problems.
-//
-// If you are seeing a lot of "proc macro not expanded" warnings, you can add this option to the
-// `rust-analyzer.diagnostics.disabled` list to prevent them from showing. Alternatively you can
-// enable support for procedural macros (see `rust-analyzer.procMacro.attributes.enable`).
-pub(crate) fn unresolved_proc_macro(
-    ctx: &DiagnosticsContext<'_>,
-    d: &hir::UnresolvedProcMacro,
-    proc_macros_enabled: bool,
-    proc_attr_macros_enabled: bool,
-) -> Diagnostic {
-    // Use more accurate position if available.
-    let display_range = ctx.resolve_precise_location(&d.node, d.precise_location);
-
-    let config_enabled = match d.kind {
-        hir::MacroKind::Attr => proc_macros_enabled && proc_attr_macros_enabled,
-        _ => proc_macros_enabled,
-    };
-
-    let not_expanded_message = match &d.macro_name {
-        Some(name) => format!("proc macro `{name}` not expanded"),
-        None => "proc macro not expanded".to_owned(),
-    };
-    let severity = if config_enabled { Severity::Error } else { Severity::WeakWarning };
-    let def_map = ctx.sema.db.crate_def_map(d.krate);
-    let message = if config_enabled {
-        def_map.proc_macro_loading_error().unwrap_or("internal error")
-    } else {
-        match d.kind {
-            hir::MacroKind::Attr if proc_macros_enabled => "attribute macro expansion is disabled",
-            _ => "proc-macro expansion is disabled",
-        }
-    };
-    let message = format!("{not_expanded_message}: {message}");
-
-    Diagnostic::new(DiagnosticCode::Ra("unresolved-proc-macro", severity), message, display_range)
-}
diff --git a/crates/ide-diagnostics/src/lib.rs b/crates/ide-diagnostics/src/lib.rs
index 9523cc81b8..263ab74755 100644
--- a/crates/ide-diagnostics/src/lib.rs
+++ b/crates/ide-diagnostics/src/lib.rs
@@ -62,7 +62,6 @@ mod handlers {
     pub(crate) mod unresolved_macro_call;
     pub(crate) mod unresolved_method;
     pub(crate) mod unresolved_module;
-    pub(crate) mod unresolved_proc_macro;
     pub(crate) mod unused_variables;
 
     // The handlers below are unusual, the implement the diagnostics as well.
@@ -405,7 +404,6 @@ pub fn diagnostics(
             AnyDiagnostic::UnresolvedMacroCall(d) => handlers::unresolved_macro_call::unresolved_macro_call(&ctx, &d),
             AnyDiagnostic::UnresolvedMethodCall(d) => handlers::unresolved_method::unresolved_method(&ctx, &d),
             AnyDiagnostic::UnresolvedModule(d) => handlers::unresolved_module::unresolved_module(&ctx, &d),
-            AnyDiagnostic::UnresolvedProcMacro(d) => handlers::unresolved_proc_macro::unresolved_proc_macro(&ctx, &d, config.proc_macros_enabled, config.proc_attr_macros_enabled),
             AnyDiagnostic::UnusedMut(d) => match handlers::mutability_errors::unused_mut(&ctx, &d) {
                 Some(it) => it,
                 None => continue,
diff --git a/crates/ide/src/lib.rs b/crates/ide/src/lib.rs
index 34a6f154db..8cb81a9cc4 100644
--- a/crates/ide/src/lib.rs
+++ b/crates/ide/src/lib.rs
@@ -43,7 +43,6 @@ mod parent_module;
 mod references;
 mod rename;
 mod runnables;
-mod shuffle_crate_graph;
 mod signature_help;
 mod ssr;
 mod static_index;
@@ -202,10 +201,6 @@ impl AnalysisHost {
     pub fn raw_database_mut(&mut self) -> &mut RootDatabase {
         &mut self.db
     }
-
-    pub fn shuffle_crate_graph(&mut self) {
-        shuffle_crate_graph::shuffle_crate_graph(&mut self.db);
-    }
 }
 
 impl Default for AnalysisHost {
diff --git a/crates/ide/src/shuffle_crate_graph.rs b/crates/ide/src/shuffle_crate_graph.rs
deleted file mode 100644
index 453d1836e1..0000000000
--- a/crates/ide/src/shuffle_crate_graph.rs
+++ /dev/null
@@ -1,58 +0,0 @@
-use hir::{db::ExpandDatabase, ProcMacros};
-use ide_db::{
-    base_db::{salsa::Durability, CrateGraph, SourceDatabase},
-    FxHashMap, RootDatabase,
-};
-use triomphe::Arc;
-
-// Feature: Shuffle Crate Graph
-//
-// Randomizes all crate IDs in the crate graph, for debugging.
-//
-// |===
-// | Editor  | Action Name
-//
-// | VS Code | **rust-analyzer: Shuffle Crate Graph**
-// |===
-pub(crate) fn shuffle_crate_graph(db: &mut RootDatabase) {
-    let crate_graph = db.crate_graph();
-    let proc_macros = db.proc_macros();
-
-    let mut shuffled_ids = crate_graph.iter().collect::<Vec<_>>();
-
-    let mut rng = oorandom::Rand32::new(stdx::rand::seed());
-    stdx::rand::shuffle(&mut shuffled_ids, |i| rng.rand_range(0..i as u32) as usize);
-
-    let mut new_graph = CrateGraph::default();
-    let mut new_proc_macros = ProcMacros::default();
-
-    let mut map = FxHashMap::default();
-    for old_id in shuffled_ids.iter().copied() {
-        let data = &crate_graph[old_id];
-        let new_id = new_graph.add_crate_root(
-            data.root_file_id,
-            data.edition,
-            data.display_name.clone(),
-            data.version.clone(),
-            data.cfg_options.clone(),
-            data.potential_cfg_options.clone(),
-            data.env.clone(),
-            data.is_proc_macro,
-            data.origin.clone(),
-        );
-        new_proc_macros.insert(new_id, proc_macros[&old_id].clone());
-        map.insert(old_id, new_id);
-    }
-
-    for old_id in shuffled_ids.iter().copied() {
-        let data = &crate_graph[old_id];
-        for dep in &data.dependencies {
-            let mut new_dep = dep.clone();
-            new_dep.crate_id = map[&dep.crate_id];
-            new_graph.add_dep(map[&old_id], new_dep).unwrap();
-        }
-    }
-
-    db.set_crate_graph_with_durability(Arc::new(new_graph), Durability::HIGH);
-    db.set_proc_macros_with_durability(Arc::new(new_proc_macros), Durability::HIGH);
-}
diff --git a/crates/load-cargo/src/lib.rs b/crates/load-cargo/src/lib.rs
index 9ad5c68a55..8737f2246b 100644
--- a/crates/load-cargo/src/lib.rs
+++ b/crates/load-cargo/src/lib.rs
@@ -68,11 +68,14 @@ pub fn load_workspace(
     let proc_macro_server = match &load_config.with_proc_macro_server {
         ProcMacroServerChoice::Sysroot => ws
             .find_sysroot_proc_macro_srv()
-            .and_then(|it| ProcMacroServer::spawn(&it, extra_env).map_err(Into::into)),
+            .and_then(|it| ProcMacroServer::spawn(&it, extra_env).map_err(Into::into))
+            .map_err(|e| (e, true)),
         ProcMacroServerChoice::Explicit(path) => {
-            ProcMacroServer::spawn(path, extra_env).map_err(Into::into)
+            ProcMacroServer::spawn(path, extra_env).map_err(Into::into).map_err(|e| (e, true))
+        }
+        ProcMacroServerChoice::None => {
+            Err((anyhow::format_err!("proc macro server disabled"), false))
         }
-        ProcMacroServerChoice::None => Err(anyhow::format_err!("proc macro server disabled")),
     };
 
     let (crate_graph, proc_macros) = ws.to_crate_graph(
@@ -87,7 +90,7 @@ pub fn load_workspace(
     let proc_macros = {
         let proc_macro_server = match &proc_macro_server {
             Ok(it) => Ok(it),
-            Err(e) => Err(e.to_string()),
+            Err((e, hard_err)) => Err((e.to_string(), *hard_err)),
         };
         proc_macros
             .into_iter()
@@ -95,7 +98,7 @@ pub fn load_workspace(
                 (
                     crate_id,
                     path.map_or_else(
-                        |_| Err("proc macro crate is missing dylib".to_owned()),
+                        |e| Err((e, true)),
                         |(_, path)| {
                             proc_macro_server.as_ref().map_err(Clone::clone).and_then(
                                 |proc_macro_server| load_proc_macro(proc_macro_server, &path, &[]),
@@ -355,8 +358,7 @@ impl SourceRootConfig {
     }
 }
 
-/// Load the proc-macros for the given lib path, replacing all expanders whose names are in `dummy_replace`
-/// with an identity dummy expander.
+/// Load the proc-macros for the given lib path, disabling all expanders whose names are in `ignored_macros`.
 pub fn load_proc_macro(
     server: &ProcMacroServer,
     path: &AbsPath,
@@ -383,7 +385,7 @@ pub fn load_proc_macro(
         }
         Err(e) => {
             tracing::warn!("proc-macro loading for {path} failed: {e}");
-            Err(e)
+            Err((e, true))
         }
     }
 }
diff --git a/crates/mbe/src/benchmark.rs b/crates/mbe/src/benchmark.rs
index 1db2789eb3..b6db4d2e76 100644
--- a/crates/mbe/src/benchmark.rs
+++ b/crates/mbe/src/benchmark.rs
@@ -45,7 +45,7 @@ fn benchmark_expand_macro_rules() {
         invocations
             .into_iter()
             .map(|(id, tt)| {
-                let res = rules[&id].expand(&tt, |_| (), true, DUMMY, Edition::CURRENT);
+                let res = rules[&id].expand(&tt, |_| (), DUMMY, Edition::CURRENT);
                 assert!(res.err.is_none());
                 res.value.0.token_trees.len()
             })
@@ -118,7 +118,7 @@ fn invocation_fixtures(
                         },
                         token_trees: token_trees.into_boxed_slice(),
                     };
-                    if it.expand(&subtree, |_| (), true, DUMMY, Edition::CURRENT).err.is_none() {
+                    if it.expand(&subtree, |_| (), DUMMY, Edition::CURRENT).err.is_none() {
                         res.push((name.clone(), subtree));
                         break;
                     }
diff --git a/crates/mbe/src/expander.rs b/crates/mbe/src/expander.rs
index 55b89aa848..1979e5171a 100644
--- a/crates/mbe/src/expander.rs
+++ b/crates/mbe/src/expander.rs
@@ -9,13 +9,12 @@ use intern::Symbol;
 use rustc_hash::FxHashMap;
 use span::{Edition, Span};
 
-use crate::{parser::MetaVarKind, ExpandError, ExpandResult, MatchedArmIndex};
+use crate::{parser::MetaVarKind, ExpandError, ExpandErrorKind, ExpandResult, MatchedArmIndex};
 
 pub(crate) fn expand_rules(
     rules: &[crate::Rule],
     input: &tt::Subtree<Span>,
     marker: impl Fn(&mut Span) + Copy,
-    new_meta_vars: bool,
     call_site: Span,
     def_site_edition: Edition,
 ) -> ExpandResult<(tt::Subtree<Span>, MatchedArmIndex)> {
@@ -27,13 +26,8 @@ pub(crate) fn expand_rules(
             // If we find a rule that applies without errors, we're done.
             // Unconditionally returning the transcription here makes the
             // `test_repeat_bad_var` test fail.
-            let ExpandResult { value, err: transcribe_err } = transcriber::transcribe(
-                &rule.rhs,
-                &new_match.bindings,
-                marker,
-                new_meta_vars,
-                call_site,
-            );
+            let ExpandResult { value, err: transcribe_err } =
+                transcriber::transcribe(&rule.rhs, &new_match.bindings, marker, call_site);
             if transcribe_err.is_none() {
                 return ExpandResult::ok((value, Some(idx as u32)));
             }
@@ -52,7 +46,7 @@ pub(crate) fn expand_rules(
     if let Some((match_, rule, idx)) = match_ {
         // if we got here, there was no match without errors
         let ExpandResult { value, err: transcribe_err } =
-            transcriber::transcribe(&rule.rhs, &match_.bindings, marker, new_meta_vars, call_site);
+            transcriber::transcribe(&rule.rhs, &match_.bindings, marker, call_site);
         ExpandResult { value: (value, idx.try_into().ok()), err: match_.err.or(transcribe_err) }
     } else {
         ExpandResult::new(
@@ -63,7 +57,7 @@ pub(crate) fn expand_rules(
                 },
                 None,
             ),
-            ExpandError::NoMatchingRule,
+            ExpandError::new(call_site, ExpandErrorKind::NoMatchingRule),
         )
     }
 }
diff --git a/crates/mbe/src/expander/matcher.rs b/crates/mbe/src/expander/matcher.rs
index 3762d20bab..e69d7d14e2 100644
--- a/crates/mbe/src/expander/matcher.rs
+++ b/crates/mbe/src/expander/matcher.rs
@@ -70,7 +70,7 @@ use crate::{
     expander::{Binding, Bindings, ExpandResult, Fragment},
     expect_fragment,
     parser::{MetaVarKind, Op, RepeatKind, Separator},
-    ExpandError, MetaTemplate, ValueResult,
+    ExpandError, ExpandErrorKind, MetaTemplate, ValueResult,
 };
 
 impl Bindings {
@@ -510,11 +510,17 @@ fn match_loop_inner<'t>(
                     if matches!(rhs, tt::Leaf::Literal(it) if it.symbol == lhs.symbol) {
                         item.dot.next();
                     } else {
-                        res.add_err(ExpandError::UnexpectedToken);
+                        res.add_err(ExpandError::new(
+                            *rhs.span(),
+                            ExpandErrorKind::UnexpectedToken,
+                        ));
                         item.is_error = true;
                     }
                 } else {
-                    res.add_err(ExpandError::binding_error(format!("expected literal: `{lhs}`")));
+                    res.add_err(ExpandError::binding_error(
+                        src.clone().next().map_or(delim_span.close, |it| it.first_span()),
+                        format!("expected literal: `{lhs}`"),
+                    ));
                     item.is_error = true;
                 }
                 try_push!(next_items, item);
@@ -524,11 +530,17 @@ fn match_loop_inner<'t>(
                     if matches!(rhs, tt::Leaf::Ident(it) if it.sym == lhs.sym) {
                         item.dot.next();
                     } else {
-                        res.add_err(ExpandError::UnexpectedToken);
+                        res.add_err(ExpandError::new(
+                            *rhs.span(),
+                            ExpandErrorKind::UnexpectedToken,
+                        ));
                         item.is_error = true;
                     }
                 } else {
-                    res.add_err(ExpandError::binding_error(format!("expected ident: `{lhs}`")));
+                    res.add_err(ExpandError::binding_error(
+                        src.clone().next().map_or(delim_span.close, |it| it.first_span()),
+                        format!("expected ident: `{lhs}`"),
+                    ));
                     item.is_error = true;
                 }
                 try_push!(next_items, item);
@@ -538,8 +550,8 @@ fn match_loop_inner<'t>(
                 let error = if let Ok(rhs) = fork.expect_glued_punct() {
                     let first_is_single_quote = rhs[0].char == '\'';
                     let lhs = lhs.iter().map(|it| it.char);
-                    let rhs = rhs.iter().map(|it| it.char);
-                    if lhs.clone().eq(rhs) {
+                    let rhs_ = rhs.iter().map(|it| it.char);
+                    if lhs.clone().eq(rhs_) {
                         // HACK: here we use `meta_result` to pass `TtIter` back to caller because
                         // it might have been advanced multiple times. `ValueResult` is
                         // insignificant.
@@ -552,13 +564,19 @@ fn match_loop_inner<'t>(
                     if first_is_single_quote {
                         // If the first punct token is a single quote, that's a part of a lifetime
                         // ident, not a punct.
-                        ExpandError::UnexpectedToken
+                        ExpandError::new(
+                            rhs.get(1).map_or(rhs[0].span, |it| it.span),
+                            ExpandErrorKind::UnexpectedToken,
+                        )
                     } else {
                         let lhs = lhs.collect::<String>();
-                        ExpandError::binding_error(format!("expected punct: `{lhs}`"))
+                        ExpandError::binding_error(rhs[0].span, format!("expected punct: `{lhs}`"))
                     }
                 } else {
-                    ExpandError::UnexpectedToken
+                    ExpandError::new(
+                        src.clone().next().map_or(delim_span.close, |it| it.first_span()),
+                        ExpandErrorKind::UnexpectedToken,
+                    )
                 };
 
                 res.add_err(error);
@@ -651,7 +669,7 @@ fn match_loop(pattern: &MetaTemplate, src: &tt::Subtree<Span>, edition: Edition)
                 if let Some(item) = error_recover_item {
                     res.bindings = bindings_builder.build(&item);
                 }
-                res.add_err(ExpandError::UnexpectedToken);
+                res.add_err(ExpandError::new(span.open, ExpandErrorKind::UnexpectedToken));
             }
             return res;
         }
@@ -670,7 +688,7 @@ fn match_loop(pattern: &MetaTemplate, src: &tt::Subtree<Span>, edition: Edition)
                 src = it;
                 res.unmatched_tts += src.len();
             }
-            res.add_err(ExpandError::LeftoverTokens);
+            res.add_err(ExpandError::new(span.open, ExpandErrorKind::LeftoverTokens));
 
             if let Some(error_recover_item) = error_recover_item {
                 res.bindings = bindings_builder.build(&error_recover_item);
@@ -746,9 +764,10 @@ fn match_meta_var(
 ) -> ExpandResult<Option<Fragment>> {
     let fragment = match kind {
         MetaVarKind::Path => {
-            return expect_fragment(input, parser::PrefixEntryPoint::Path, edition).map(|it| {
-                it.map(|it| tt::TokenTree::subtree_or_wrap(it, delim_span)).map(Fragment::Path)
-            });
+            return expect_fragment(input, parser::PrefixEntryPoint::Path, edition, delim_span)
+                .map(|it| {
+                    it.map(|it| tt::TokenTree::subtree_or_wrap(it, delim_span)).map(Fragment::Path)
+                });
         }
         MetaVarKind::Expr => {
             // `expr` should not match underscores, let expressions, or inline const. The latter
@@ -763,37 +782,54 @@ fn match_meta_var(
                         || it.sym == sym::let_
                         || it.sym == sym::const_ =>
                 {
-                    return ExpandResult::only_err(ExpandError::NoMatchingRule)
+                    return ExpandResult::only_err(ExpandError::new(
+                        it.span,
+                        ExpandErrorKind::NoMatchingRule,
+                    ))
                 }
                 _ => {}
             };
-            return expect_fragment(input, parser::PrefixEntryPoint::Expr, edition).map(|tt| {
-                tt.map(|tt| match tt {
-                    tt::TokenTree::Leaf(leaf) => tt::Subtree {
-                        delimiter: tt::Delimiter::invisible_spanned(*leaf.span()),
-                        token_trees: Box::new([leaf.into()]),
-                    },
-                    tt::TokenTree::Subtree(mut s) => {
-                        if s.delimiter.kind == tt::DelimiterKind::Invisible {
-                            s.delimiter.kind = tt::DelimiterKind::Parenthesis;
+            return expect_fragment(input, parser::PrefixEntryPoint::Expr, edition, delim_span)
+                .map(|tt| {
+                    tt.map(|tt| match tt {
+                        tt::TokenTree::Leaf(leaf) => tt::Subtree {
+                            delimiter: tt::Delimiter::invisible_spanned(*leaf.span()),
+                            token_trees: Box::new([leaf.into()]),
+                        },
+                        tt::TokenTree::Subtree(mut s) => {
+                            if s.delimiter.kind == tt::DelimiterKind::Invisible {
+                                s.delimiter.kind = tt::DelimiterKind::Parenthesis;
+                            }
+                            s
                         }
-                        s
-                    }
-                })
-                .map(Fragment::Expr)
-            });
+                    })
+                    .map(Fragment::Expr)
+                });
         }
         MetaVarKind::Ident | MetaVarKind::Tt | MetaVarKind::Lifetime | MetaVarKind::Literal => {
+            let span = input.next_span();
             let tt_result = match kind {
                 MetaVarKind::Ident => input
                     .expect_ident()
                     .map(|ident| tt::Leaf::from(ident.clone()).into())
-                    .map_err(|()| ExpandError::binding_error("expected ident")),
-                MetaVarKind::Tt => {
-                    expect_tt(input).map_err(|()| ExpandError::binding_error("expected token tree"))
-                }
-                MetaVarKind::Lifetime => expect_lifetime(input)
-                    .map_err(|()| ExpandError::binding_error("expected lifetime")),
+                    .map_err(|()| {
+                        ExpandError::binding_error(
+                            span.unwrap_or(delim_span.close),
+                            "expected ident",
+                        )
+                    }),
+                MetaVarKind::Tt => expect_tt(input).map_err(|()| {
+                    ExpandError::binding_error(
+                        span.unwrap_or(delim_span.close),
+                        "expected token tree",
+                    )
+                }),
+                MetaVarKind::Lifetime => expect_lifetime(input).map_err(|()| {
+                    ExpandError::binding_error(
+                        span.unwrap_or(delim_span.close),
+                        "expected lifetime",
+                    )
+                }),
                 MetaVarKind::Literal => {
                     let neg = eat_char(input, '-');
                     input
@@ -808,7 +844,12 @@ fn match_meta_var(
                                 }),
                             }
                         })
-                        .map_err(|()| ExpandError::binding_error("expected literal"))
+                        .map_err(|()| {
+                            ExpandError::binding_error(
+                                span.unwrap_or(delim_span.close),
+                                "expected literal",
+                            )
+                        })
                 }
                 _ => unreachable!(),
             };
@@ -823,7 +864,7 @@ fn match_meta_var(
         MetaVarKind::Item => parser::PrefixEntryPoint::Item,
         MetaVarKind::Vis => parser::PrefixEntryPoint::Vis,
     };
-    expect_fragment(input, fragment, edition).map(|it| it.map(Fragment::Tokens))
+    expect_fragment(input, fragment, edition, delim_span).map(|it| it.map(Fragment::Tokens))
 }
 
 fn collect_vars(collector_fun: &mut impl FnMut(Symbol), pattern: &MetaTemplate) {
diff --git a/crates/mbe/src/expander/transcriber.rs b/crates/mbe/src/expander/transcriber.rs
index 4de7cccd96..286bd748cb 100644
--- a/crates/mbe/src/expander/transcriber.rs
+++ b/crates/mbe/src/expander/transcriber.rs
@@ -8,14 +8,17 @@ use tt::Delimiter;
 use crate::{
     expander::{Binding, Bindings, Fragment},
     parser::{MetaVarKind, Op, RepeatKind, Separator},
-    CountError, ExpandError, ExpandResult, MetaTemplate,
+    ExpandError, ExpandErrorKind, ExpandResult, MetaTemplate,
 };
 
 impl Bindings {
-    fn get(&self, name: &Symbol) -> Result<&Binding, ExpandError> {
+    fn get(&self, name: &Symbol, span: Span) -> Result<&Binding, ExpandError> {
         match self.inner.get(name) {
             Some(binding) => Ok(binding),
-            None => Err(ExpandError::UnresolvedBinding(Box::new(Box::from(name.as_str())))),
+            None => Err(ExpandError::new(
+                span,
+                ExpandErrorKind::UnresolvedBinding(Box::new(Box::from(name.as_str()))),
+            )),
         }
     }
 
@@ -27,10 +30,10 @@ impl Bindings {
         marker: impl Fn(&mut Span),
     ) -> Result<Fragment, ExpandError> {
         macro_rules! binding_err {
-            ($($arg:tt)*) => { ExpandError::binding_error(format!($($arg)*)) };
+            ($($arg:tt)*) => { ExpandError::binding_error(span, format!($($arg)*)) };
         }
 
-        let mut b = self.get(name)?;
+        let mut b = self.get(name, span)?;
         for nesting_state in nesting.iter_mut() {
             nesting_state.hit = true;
             b = match b {
@@ -142,10 +145,9 @@ pub(super) fn transcribe(
     template: &MetaTemplate,
     bindings: &Bindings,
     marker: impl Fn(&mut Span) + Copy,
-    new_meta_vars: bool,
     call_site: Span,
 ) -> ExpandResult<tt::Subtree<Span>> {
-    let mut ctx = ExpandCtx { bindings, nesting: Vec::new(), new_meta_vars, call_site };
+    let mut ctx = ExpandCtx { bindings, nesting: Vec::new(), call_site };
     let mut arena: Vec<tt::TokenTree<Span>> = Vec::new();
     expand_subtree(&mut ctx, template, None, &mut arena, marker)
 }
@@ -165,7 +167,6 @@ struct NestingState {
 struct ExpandCtx<'a> {
     bindings: &'a Bindings,
     nesting: Vec<NestingState>,
-    new_meta_vars: bool,
     call_site: Span,
 }
 
@@ -263,7 +264,7 @@ fn expand_subtree(
                 );
             }
             Op::Count { name, depth } => {
-                let mut binding = match ctx.bindings.get(name) {
+                let mut binding = match ctx.bindings.get(name, ctx.call_site) {
                     Ok(b) => b,
                     Err(e) => {
                         if err.is_none() {
@@ -299,29 +300,11 @@ fn expand_subtree(
                     }
                 }
 
-                let res = if ctx.new_meta_vars {
-                    count(binding, 0, depth.unwrap_or(0))
-                } else {
-                    count_old(binding, 0, *depth)
-                };
+                let res = count(binding, 0, depth.unwrap_or(0));
 
-                let c = match res {
-                    Ok(c) => c,
-                    Err(e) => {
-                        // XXX: It *might* make sense to emit a dummy integer value like `0` here.
-                        // That would type inference a bit more robust in cases like
-                        // `v[${count(t)}]` where index doesn't matter, but also could lead to
-                        // wrong infefrence for cases like `tup.${count(t)}` where index itself
-                        // does matter.
-                        if err.is_none() {
-                            err = Some(e.into());
-                        }
-                        continue;
-                    }
-                };
                 arena.push(
                     tt::Leaf::Literal(tt::Literal {
-                        symbol: Symbol::integer(c),
+                        symbol: Symbol::integer(res),
                         span: ctx.call_site,
                         suffix: None,
                         kind: tt::LitKind::Integer,
@@ -353,7 +336,7 @@ fn expand_var(
 
     match ctx.bindings.get_fragment(v, id, &mut ctx.nesting, marker) {
         Ok(it) => ExpandResult::ok(it),
-        Err(ExpandError::UnresolvedBinding(_)) => {
+        Err(e) if matches!(e.inner.1, ExpandErrorKind::UnresolvedBinding(_)) => {
             // Note that it is possible to have a `$var` inside a macro which is not bound.
             // For example:
             // ```
@@ -435,7 +418,7 @@ fn expand_repeat(
                     }
                     .into(),
                 ),
-                err: Some(ExpandError::LimitExceeded),
+                err: Some(ExpandError::new(ctx.call_site, ExpandErrorKind::LimitExceeded)),
             };
         }
 
@@ -481,16 +464,16 @@ fn expand_repeat(
     let tt = tt::Subtree {
         delimiter: tt::Delimiter::invisible_spanned(ctx.call_site),
         token_trees: buf.into_boxed_slice(),
-    }
-    .into();
+    };
 
     if RepeatKind::OneOrMore == kind && counter == 0 {
+        let span = tt.delimiter.open;
         return ExpandResult {
-            value: Fragment::Tokens(tt),
-            err: Some(ExpandError::UnexpectedToken),
+            value: Fragment::Tokens(tt.into()),
+            err: Some(ExpandError::new(span, ExpandErrorKind::UnexpectedToken)),
         };
     }
-    ExpandResult { value: Fragment::Tokens(tt), err }
+    ExpandResult { value: Fragment::Tokens(tt.into()), err }
 }
 
 fn push_fragment(ctx: &ExpandCtx<'_>, buf: &mut Vec<tt::TokenTree<Span>>, fragment: Fragment) {
@@ -557,44 +540,16 @@ fn fix_up_and_push_path_tt(
 
 /// Handles `${count(t, depth)}`. `our_depth` is the recursion depth and `count_depth` is the depth
 /// defined by the metavar expression.
-fn count(binding: &Binding, depth_curr: usize, depth_max: usize) -> Result<usize, CountError> {
+fn count(binding: &Binding, depth_curr: usize, depth_max: usize) -> usize {
     match binding {
         Binding::Nested(bs) => {
             if depth_curr == depth_max {
-                Ok(bs.len())
+                bs.len()
             } else {
                 bs.iter().map(|b| count(b, depth_curr + 1, depth_max)).sum()
             }
         }
-        Binding::Empty => Ok(0),
-        Binding::Fragment(_) | Binding::Missing(_) => Ok(1),
-    }
-}
-
-fn count_old(
-    binding: &Binding,
-    our_depth: usize,
-    count_depth: Option<usize>,
-) -> Result<usize, CountError> {
-    match binding {
-        Binding::Nested(bs) => match count_depth {
-            None => bs.iter().map(|b| count_old(b, our_depth + 1, None)).sum(),
-            Some(0) => Ok(bs.len()),
-            Some(d) => bs.iter().map(|b| count_old(b, our_depth + 1, Some(d - 1))).sum(),
-        },
-        Binding::Empty => Ok(0),
-        Binding::Fragment(_) | Binding::Missing(_) => {
-            if our_depth == 0 {
-                // `${count(t)}` is placed inside the innermost repetition. This includes cases
-                // where `t` is not a repeated fragment.
-                Err(CountError::Misplaced)
-            } else if count_depth.is_none() {
-                Ok(1)
-            } else {
-                // We've reached at the innermost repeated fragment, but the user wants us to go
-                // further!
-                Err(CountError::OutOfBounds)
-            }
-        }
+        Binding::Empty => 0,
+        Binding::Fragment(_) | Binding::Missing(_) => 1,
     }
 }
diff --git a/crates/mbe/src/lib.rs b/crates/mbe/src/lib.rs
index bd7cb3ce7a..568490d573 100644
--- a/crates/mbe/src/lib.rs
+++ b/crates/mbe/src/lib.rs
@@ -15,10 +15,11 @@ mod to_parser_input;
 mod benchmark;
 
 use span::{Edition, Span, SyntaxContextId};
-use stdx::impl_from;
 use tt::iter::TtIter;
+use tt::DelimSpan;
 
 use std::fmt;
+use std::sync::Arc;
 
 use crate::parser::{MetaTemplate, MetaVarKind, Op};
 
@@ -64,39 +65,45 @@ impl fmt::Display for ParseError {
 }
 
 #[derive(Debug, PartialEq, Eq, Clone, Hash)]
-pub enum ExpandError {
+pub struct ExpandError {
+    pub inner: Arc<(Span, ExpandErrorKind)>,
+}
+#[derive(Debug, PartialEq, Eq, Clone, Hash)]
+pub enum ExpandErrorKind {
     BindingError(Box<Box<str>>),
     UnresolvedBinding(Box<Box<str>>),
     LeftoverTokens,
-    ConversionError,
     LimitExceeded,
     NoMatchingRule,
     UnexpectedToken,
-    CountError(CountError),
 }
 
-impl_from!(CountError for ExpandError);
-
 impl ExpandError {
-    fn binding_error(e: impl Into<Box<str>>) -> ExpandError {
-        ExpandError::BindingError(Box::new(e.into()))
+    fn new(span: Span, kind: ExpandErrorKind) -> ExpandError {
+        ExpandError { inner: Arc::new((span, kind)) }
+    }
+    fn binding_error(span: Span, e: impl Into<Box<str>>) -> ExpandError {
+        ExpandError { inner: Arc::new((span, ExpandErrorKind::BindingError(Box::new(e.into())))) }
+    }
+}
+impl fmt::Display for ExpandError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.inner.1.fmt(f)
     }
 }
 
-impl fmt::Display for ExpandError {
+impl fmt::Display for ExpandErrorKind {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self {
-            ExpandError::NoMatchingRule => f.write_str("no rule matches input tokens"),
-            ExpandError::UnexpectedToken => f.write_str("unexpected token in input"),
-            ExpandError::BindingError(e) => f.write_str(e),
-            ExpandError::UnresolvedBinding(binding) => {
+            ExpandErrorKind::NoMatchingRule => f.write_str("no rule matches input tokens"),
+            ExpandErrorKind::UnexpectedToken => f.write_str("unexpected token in input"),
+            ExpandErrorKind::BindingError(e) => f.write_str(e),
+            ExpandErrorKind::UnresolvedBinding(binding) => {
                 f.write_str("could not find binding ")?;
                 f.write_str(binding)
             }
-            ExpandError::ConversionError => f.write_str("could not convert tokens"),
-            ExpandError::LimitExceeded => f.write_str("Expand exceed limit"),
-            ExpandError::LeftoverTokens => f.write_str("leftover tokens"),
-            ExpandError::CountError(e) => e.fmt(f),
+            ExpandErrorKind::LimitExceeded => f.write_str("Expand exceed limit"),
+            ExpandErrorKind::LeftoverTokens => f.write_str("leftover tokens"),
         }
     }
 }
@@ -248,11 +255,10 @@ impl DeclarativeMacro {
         &self,
         tt: &tt::Subtree<Span>,
         marker: impl Fn(&mut Span) + Copy,
-        new_meta_vars: bool,
         call_site: Span,
         def_site_edition: Edition,
     ) -> ExpandResult<(tt::Subtree<Span>, MatchedArmIndex)> {
-        expander::expand_rules(&self.rules, tt, marker, new_meta_vars, call_site, def_site_edition)
+        expander::expand_rules(&self.rules, tt, marker, call_site, def_site_edition)
     }
 }
 
@@ -355,11 +361,12 @@ impl<T: Default, E> From<Result<T, E>> for ValueResult<T, E> {
     }
 }
 
-fn expect_fragment<S: Copy + fmt::Debug>(
-    tt_iter: &mut TtIter<'_, S>,
+fn expect_fragment(
+    tt_iter: &mut TtIter<'_, Span>,
     entry_point: ::parser::PrefixEntryPoint,
     edition: ::parser::Edition,
-) -> ExpandResult<Option<tt::TokenTree<S>>> {
+    delim_span: DelimSpan<Span>,
+) -> ExpandResult<Option<tt::TokenTree<Span>>> {
     use ::parser;
     let buffer = tt::buffer::TokenBuffer::from_tokens(tt_iter.as_slice());
     let parser_input = to_parser_input::to_parser_input(edition, &buffer);
@@ -387,7 +394,10 @@ fn expect_fragment<S: Copy + fmt::Debug>(
     }
 
     let err = if error || !cursor.is_root() {
-        Some(ExpandError::binding_error(format!("expected {entry_point:?}")))
+        Some(ExpandError::binding_error(
+            buffer.begin().token_tree().map_or(delim_span.close, |tt| tt.span()),
+            format!("expected {entry_point:?}"),
+        ))
     } else {
         None
     };
diff --git a/crates/mbe/src/syntax_bridge.rs b/crates/mbe/src/syntax_bridge.rs
index ee61d7a21b..a29efdd4ef 100644
--- a/crates/mbe/src/syntax_bridge.rs
+++ b/crates/mbe/src/syntax_bridge.rs
@@ -212,15 +212,12 @@ where
 }
 
 /// Split token tree with separate expr: $($e:expr)SEP*
-pub fn parse_exprs_with_sep<S>(
-    tt: &tt::Subtree<S>,
+pub fn parse_exprs_with_sep(
+    tt: &tt::Subtree<span::Span>,
     sep: char,
-    span: S,
+    span: span::Span,
     edition: Edition,
-) -> Vec<tt::Subtree<S>>
-where
-    S: Copy + fmt::Debug,
-{
+) -> Vec<tt::Subtree<span::Span>> {
     if tt.token_trees.is_empty() {
         return Vec::new();
     }
@@ -229,7 +226,12 @@ where
     let mut res = Vec::new();
 
     while iter.peek_n(0).is_some() {
-        let expanded = crate::expect_fragment(&mut iter, parser::PrefixEntryPoint::Expr, edition);
+        let expanded = crate::expect_fragment(
+            &mut iter,
+            parser::PrefixEntryPoint::Expr,
+            edition,
+            tt::DelimSpan { open: tt.delimiter.open, close: tt.delimiter.close },
+        );
 
         res.push(match expanded.value {
             None => break,
diff --git a/crates/project-model/src/workspace.rs b/crates/project-model/src/workspace.rs
index bfbdf03835..31d1c77fd0 100644
--- a/crates/project-model/src/workspace.rs
+++ b/crates/project-model/src/workspace.rs
@@ -934,7 +934,10 @@ fn project_json_to_crate_graph(
                 if *is_proc_macro {
                     if let Some(path) = proc_macro_dylib_path.clone() {
                         let node = Ok((
-                            display_name.as_ref().map(|it| it.canonical_name().as_str().to_owned()),
+                            display_name
+                                .as_ref()
+                                .map(|it| it.canonical_name().as_str().to_owned())
+                                .unwrap_or_else(|| format!("crate{}", idx.0)),
                             path,
                         ));
                         proc_macros.insert(crate_graph_crate_id, node);
@@ -1355,8 +1358,8 @@ fn add_target_crate_root(
     );
     if let TargetKind::Lib { is_proc_macro: true } = kind {
         let proc_macro = match build_data.as_ref().map(|it| it.proc_macro_dylib_path.as_ref()) {
-            Some(it) => it.cloned().map(|path| Ok((Some(cargo_name.to_owned()), path))),
-            None => Some(Err("crate has not yet been built".to_owned())),
+            Some(it) => it.cloned().map(|path| Ok((cargo_name.to_owned(), path))),
+            None => Some(Err("proc-macro crate is missing its build data".to_owned())),
         };
         if let Some(proc_macro) = proc_macro {
             proc_macros.insert(crate_id, proc_macro);
diff --git a/crates/rust-analyzer/src/handlers/request.rs b/crates/rust-analyzer/src/handlers/request.rs
index 9bb3146322..f64c47fbfd 100644
--- a/crates/rust-analyzer/src/handlers/request.rs
+++ b/crates/rust-analyzer/src/handlers/request.rs
@@ -134,11 +134,6 @@ pub(crate) fn handle_memory_usage(state: &mut GlobalState, _: ()) -> anyhow::Res
     Ok(out)
 }
 
-pub(crate) fn handle_shuffle_crate_graph(state: &mut GlobalState, _: ()) -> anyhow::Result<()> {
-    state.analysis_host.shuffle_crate_graph();
-    Ok(())
-}
-
 pub(crate) fn handle_syntax_tree(
     snap: GlobalStateSnapshot,
     params: lsp_ext::SyntaxTreeParams,
diff --git a/crates/rust-analyzer/src/lsp/ext.rs b/crates/rust-analyzer/src/lsp/ext.rs
index 813e9fcd47..1fcb636f85 100644
--- a/crates/rust-analyzer/src/lsp/ext.rs
+++ b/crates/rust-analyzer/src/lsp/ext.rs
@@ -75,14 +75,6 @@ impl Request for MemoryUsage {
     const METHOD: &'static str = "rust-analyzer/memoryUsage";
 }
 
-pub enum ShuffleCrateGraph {}
-
-impl Request for ShuffleCrateGraph {
-    type Params = ();
-    type Result = ();
-    const METHOD: &'static str = "rust-analyzer/shuffleCrateGraph";
-}
-
 pub enum ReloadWorkspace {}
 
 impl Request for ReloadWorkspace {
diff --git a/crates/rust-analyzer/src/main_loop.rs b/crates/rust-analyzer/src/main_loop.rs
index e64095ba9e..58d73611c6 100644
--- a/crates/rust-analyzer/src/main_loop.rs
+++ b/crates/rust-analyzer/src/main_loop.rs
@@ -1018,7 +1018,6 @@ impl GlobalState {
             .on_sync_mut::<lsp_ext::ReloadWorkspace>(handlers::handle_workspace_reload)
             .on_sync_mut::<lsp_ext::RebuildProcMacros>(handlers::handle_proc_macros_rebuild)
             .on_sync_mut::<lsp_ext::MemoryUsage>(handlers::handle_memory_usage)
-            .on_sync_mut::<lsp_ext::ShuffleCrateGraph>(handlers::handle_shuffle_crate_graph)
             .on_sync_mut::<lsp_ext::RunTest>(handlers::handle_run_test)
             // Request handlers which are related to the user typing
             // are run on the main thread to reduce latency:
@@ -1054,6 +1053,7 @@ impl GlobalState {
             .on::<NO_RETRY, lsp_request::GotoDeclaration>(handlers::handle_goto_declaration)
             .on::<NO_RETRY, lsp_request::GotoImplementation>(handlers::handle_goto_implementation)
             .on::<NO_RETRY, lsp_request::GotoTypeDefinition>(handlers::handle_goto_type_definition)
+            // FIXME: This should not be tried as it contains offsets that can get outdated!
             .on::<RETRY, lsp_request::InlayHintRequest>(handlers::handle_inlay_hints)
             .on::<RETRY, lsp_request::InlayHintResolveRequest>(handlers::handle_inlay_hints_resolve)
             .on::<NO_RETRY, lsp_request::CodeLensRequest>(handlers::handle_code_lens)
diff --git a/crates/rust-analyzer/src/reload.rs b/crates/rust-analyzer/src/reload.rs
index fb16f28a14..c2463e0ebe 100644
--- a/crates/rust-analyzer/src/reload.rs
+++ b/crates/rust-analyzer/src/reload.rs
@@ -16,8 +16,7 @@
 use std::{iter, mem};
 
 use flycheck::{FlycheckConfig, FlycheckHandle};
-use hir::{db::DefDatabase, ChangeWithProcMacros, ProcMacros};
-use ide::CrateId;
+use hir::{db::DefDatabase, ChangeWithProcMacros, ProcMacros, ProcMacrosBuilder};
 use ide_db::{
     base_db::{salsa::Durability, CrateGraph, ProcMacroPaths, Version},
     FxHashMap,
@@ -371,43 +370,44 @@ impl GlobalState {
                 }
             };
 
-            let mut res = FxHashMap::default();
+            let mut builder = ProcMacrosBuilder::default();
             let chain = proc_macro_clients
                 .iter()
                 .map(|res| res.as_ref().map_err(|e| e.to_string()))
-                .chain(iter::repeat_with(|| Err("Proc macros servers are not running".into())));
+                .chain(iter::repeat_with(|| Err("proc-macro-srv is not running".into())));
             for (client, paths) in chain.zip(paths) {
-                res.extend(paths.into_iter().map(move |(crate_id, res)| {
-                    (
-                        crate_id,
-                        res.map_or_else(
-                            |_| Err("proc macro crate is missing dylib".to_owned()),
-                            |(crate_name, path)| {
-                                progress(path.to_string());
-                                client.as_ref().map_err(Clone::clone).and_then(|client| {
-                                    load_proc_macro(
-                                        client,
-                                        &path,
-                                        crate_name
-                                            .as_deref()
-                                            .and_then(|crate_name| {
-                                                ignored_proc_macros.iter().find_map(
-                                                    |(name, macros)| {
-                                                        eq_ignore_underscore(name, crate_name)
+                paths
+                    .into_iter()
+                    .map(move |(crate_id, res)| {
+                        (
+                            crate_id,
+                            res.map_or_else(
+                                |e| Err((e, true)),
+                                |(crate_name, path)| {
+                                    progress(path.to_string());
+                                    client.as_ref().map_err(|it| (it.clone(), true)).and_then(
+                                        |client| {
+                                            load_proc_macro(
+                                                client,
+                                                &path,
+                                                ignored_proc_macros
+                                                    .iter()
+                                                    .find_map(|(name, macros)| {
+                                                        eq_ignore_underscore(name, &crate_name)
                                                             .then_some(&**macros)
-                                                    },
-                                                )
-                                            })
-                                            .unwrap_or_default(),
+                                                    })
+                                                    .unwrap_or_default(),
+                                            )
+                                        },
                                     )
-                                })
-                            },
-                        ),
-                    )
-                }));
+                                },
+                            ),
+                        )
+                    })
+                    .for_each(|(krate, res)| builder.insert(krate, res));
             }
 
-            sender.send(Task::LoadProcMacros(ProcMacroProgress::End(res))).unwrap();
+            sender.send(Task::LoadProcMacros(ProcMacroProgress::End(builder.build()))).unwrap();
         });
     }
 
@@ -667,10 +667,17 @@ impl GlobalState {
             change.set_proc_macros(
                 crate_graph
                     .iter()
-                    .map(|id| (id, Err("Proc-macros have not been built yet".to_owned())))
+                    .map(|id| (id, Err(("proc-macro has not been built yet".to_owned(), true))))
                     .collect(),
             );
             self.fetch_proc_macros_queue.request_op(cause, proc_macro_paths);
+        } else {
+            change.set_proc_macros(
+                crate_graph
+                    .iter()
+                    .map(|id| (id, Err(("proc-macro expansion is disabled".to_owned(), false))))
+                    .collect(),
+            );
         }
         change.set_crate_graph(crate_graph);
         change.set_target_data_layouts(layouts);
@@ -809,12 +816,7 @@ pub fn ws_to_crate_graph(
     workspaces: &[ProjectWorkspace],
     extra_env: &FxHashMap<String, String>,
     mut load: impl FnMut(&AbsPath) -> Option<vfs::FileId>,
-) -> (
-    CrateGraph,
-    Vec<FxHashMap<CrateId, Result<(Option<String>, AbsPathBuf), String>>>,
-    Vec<Result<Arc<str>, Arc<str>>>,
-    Vec<Option<Version>>,
-) {
+) -> (CrateGraph, Vec<ProcMacroPaths>, Vec<Result<Arc<str>, Arc<str>>>, Vec<Option<Version>>) {
     let mut crate_graph = CrateGraph::default();
     let mut proc_macro_paths = Vec::default();
     let mut layouts = Vec::default();
diff --git a/crates/span/src/lib.rs b/crates/span/src/lib.rs
index 057fab89c7..b4e21d64f8 100644
--- a/crates/span/src/lib.rs
+++ b/crates/span/src/lib.rs
@@ -33,6 +33,16 @@ pub const FIXUP_ERASED_FILE_AST_ID_MARKER: ErasedFileAstId =
 
 pub type Span = SpanData<SyntaxContextId>;
 
+impl Span {
+    pub fn cover(self, other: Span) -> Span {
+        if self.anchor != other.anchor {
+            return self;
+        }
+        let range = self.range.cover(other.range);
+        Span { range, ..self }
+    }
+}
+
 /// Spans represent a region of code, used by the IDE to be able link macro inputs and outputs
 /// together. Positions in spans are relative to some [`SpanAnchor`] to make them more incremental
 /// friendly.
diff --git a/crates/test-fixture/src/lib.rs b/crates/test-fixture/src/lib.rs
index c10ff4aede..e1f40f5da0 100644
--- a/crates/test-fixture/src/lib.rs
+++ b/crates/test-fixture/src/lib.rs
@@ -1,5 +1,5 @@
 //! A set of high-level utility fixture methods to use in tests.
-use std::{iter, mem, ops::Not, str::FromStr, sync};
+use std::{iter, mem, str::FromStr, sync};
 
 use base_db::{
     CrateDisplayName, CrateGraph, CrateId, CrateName, CrateOrigin, Dependency, Env, FileChange,
@@ -11,7 +11,7 @@ use hir_expand::{
     db::ExpandDatabase,
     files::FilePosition,
     proc_macro::{
-        ProcMacro, ProcMacroExpander, ProcMacroExpansionError, ProcMacroKind, ProcMacros,
+        ProcMacro, ProcMacroExpander, ProcMacroExpansionError, ProcMacroKind, ProcMacrosBuilder,
     },
     FileRange,
 };
@@ -303,7 +303,7 @@ impl ChangeFixture {
             }
         }
 
-        let mut proc_macros = ProcMacros::default();
+        let mut proc_macros = ProcMacrosBuilder::default();
         if !proc_macro_names.is_empty() {
             let proc_lib_file = file_id;
 
@@ -354,7 +354,7 @@ impl ChangeFixture {
 
         let mut change = ChangeWithProcMacros {
             source_change,
-            proc_macros: proc_macros.is_empty().not().then_some(proc_macros),
+            proc_macros: Some(proc_macros.build()),
             toolchains: Some(iter::repeat(toolchain).take(crate_graph.len()).collect()),
             target_data_layouts: Some(
                 iter::repeat(target_data_layout).take(crate_graph.len()).collect(),
diff --git a/crates/tt/src/buffer.rs b/crates/tt/src/buffer.rs
index cd41af03c6..1319739371 100644
--- a/crates/tt/src/buffer.rs
+++ b/crates/tt/src/buffer.rs
@@ -134,6 +134,15 @@ pub enum TokenTreeRef<'a, Span> {
     Leaf(&'a Leaf<Span>, &'a TokenTree<Span>),
 }
 
+impl<'a, Span: Copy> TokenTreeRef<'a, Span> {
+    pub fn span(&self) -> Span {
+        match self {
+            TokenTreeRef::Subtree(subtree, _) => subtree.delimiter.open,
+            TokenTreeRef::Leaf(leaf, _) => *leaf.span(),
+        }
+    }
+}
+
 impl<Span: Clone> TokenTreeRef<'_, Span> {
     pub fn cloned(&self) -> TokenTree<Span> {
         match self {
diff --git a/crates/tt/src/iter.rs b/crates/tt/src/iter.rs
index c0195b835a..e96bed0319 100644
--- a/crates/tt/src/iter.rs
+++ b/crates/tt/src/iter.rs
@@ -143,6 +143,10 @@ impl<'a, S: Copy> TtIter<'a, S> {
         self.inner.as_slice().get(n)
     }
 
+    pub fn next_span(&self) -> Option<S> {
+        Some(self.inner.as_slice().first()?.first_span())
+    }
+
     pub fn as_slice(&self) -> &'a [TokenTree<S>] {
         self.inner.as_slice()
     }
diff --git a/docs/dev/lsp-extensions.md b/docs/dev/lsp-extensions.md
index a29b42a857..e559f88e23 100644
--- a/docs/dev/lsp-extensions.md
+++ b/docs/dev/lsp-extensions.md
@@ -1,5 +1,5 @@
 <!---
-lsp/ext.rs hash: f41950db4c7b3a5a
+lsp/ext.rs hash: e92e1f12229b0071
 
 If you need to change the above hash to make the test pass, please check if you
 need to adjust this doc as well and ping this issue:
@@ -789,14 +789,6 @@ Renders rust-analyzer's crate graph as an SVG image.
 
 If `full` is `true`, the graph includes non-workspace crates (crates.io dependencies as well as sysroot crates).
 
-## Shuffle Crate Graph
-
-**Method:** `rust-analyzer/shuffleCrateGraph`
-
-**Request:** `null`
-
-Shuffles the crate IDs in the crate graph, for debugging purposes.
-
 ## Expand Macro
 
 **Method:** `rust-analyzer/expandMacro`
diff --git a/editors/code/package.json b/editors/code/package.json
index da06f133d0..40552cab40 100644
--- a/editors/code/package.json
+++ b/editors/code/package.json
@@ -136,11 +136,6 @@
                 "title": "Debug ItemTree",
                 "category": "rust-analyzer (debug command)"
             },
-            {
-                "command": "rust-analyzer.shuffleCrateGraph",
-                "title": "Shuffle Crate Graph",
-                "category": "rust-analyzer (debug command)"
-            },
             {
                 "command": "rust-analyzer.memoryUsage",
                 "title": "Memory Usage (Clears Database)",
diff --git a/editors/code/src/commands.ts b/editors/code/src/commands.ts
index 773a460601..7ebc186a3e 100644
--- a/editors/code/src/commands.ts
+++ b/editors/code/src/commands.ts
@@ -100,12 +100,6 @@ export function memoryUsage(ctx: CtxInit): Cmd {
     };
 }
 
-export function shuffleCrateGraph(ctx: CtxInit): Cmd {
-    return async () => {
-        return ctx.client.sendRequest(ra.shuffleCrateGraph);
-    };
-}
-
 export function triggerParameterHints(_: CtxInit): Cmd {
     return async () => {
         const parameterHintsEnabled = vscode.workspace
diff --git a/editors/code/src/lsp_ext.ts b/editors/code/src/lsp_ext.ts
index 2a7b51eaa1..d52e314e21 100644
--- a/editors/code/src/lsp_ext.ts
+++ b/editors/code/src/lsp_ext.ts
@@ -45,7 +45,6 @@ export const rebuildProcMacros = new lc.RequestType0<null, void>("rust-analyzer/
 export const runFlycheck = new lc.NotificationType<{
     textDocument: lc.TextDocumentIdentifier | null;
 }>("rust-analyzer/runFlycheck");
-export const shuffleCrateGraph = new lc.RequestType0<null, void>("rust-analyzer/shuffleCrateGraph");
 export const syntaxTree = new lc.RequestType<SyntaxTreeParams, string, void>(
     "rust-analyzer/syntaxTree",
 );
diff --git a/editors/code/src/main.ts b/editors/code/src/main.ts
index 381c7b0571..4769fdd864 100644
--- a/editors/code/src/main.ts
+++ b/editors/code/src/main.ts
@@ -141,7 +141,6 @@ function createCommands(): Record<string, CommandFactory> {
 
         analyzerStatus: { enabled: commands.analyzerStatus },
         memoryUsage: { enabled: commands.memoryUsage },
-        shuffleCrateGraph: { enabled: commands.shuffleCrateGraph },
         reloadWorkspace: { enabled: commands.reloadWorkspace },
         rebuildProcMacros: { enabled: commands.rebuildProcMacros },
         matchingBrace: { enabled: commands.matchingBrace },