Drop support for non-syroot proc macro ABIs

crates/proc-macro-srv/src/proc_macros.rs

@@ -0,0 +1,133 @@
+//! Proc macro ABI
+
+use libloading::Library;
+use proc_macro_api::{ProcMacroKind, RustCInfo};
+
+use crate::{dylib::LoadProcMacroDylibError, tt};
+
+pub(crate) struct ProcMacros {
+    exported_macros: Vec<proc_macro::bridge::client::ProcMacro>,
+}
+
+impl From<proc_macro::bridge::PanicMessage> for crate::PanicMessage {
+    fn from(p: proc_macro::bridge::PanicMessage) -> Self {
+        Self { message: p.as_str().map(|s| s.to_string()) }
+    }
+}
+
+impl ProcMacros {
+    /// Load a new ABI.
+    ///
+    /// # Arguments
+    ///
+    /// *`lib` - The dynamic library containing the macro implementations
+    /// *`symbol_name` - The symbol name the macros can be found attributes
+    /// *`info` - RustCInfo about the compiler that was used to compile the
+    ///           macro crate. This is the information we use to figure out
+    ///           which ABI to return
+    pub fn from_lib(
+        lib: &Library,
+        symbol_name: String,
+        info: RustCInfo,
+    ) -> Result<ProcMacros, LoadProcMacroDylibError> {
+        if info.version_string == crate::RUSTC_VERSION_STRING {
+            let macros = unsafe {
+                lib.get::<&&[proc_macro::bridge::client::ProcMacro]>(symbol_name.as_bytes())
+            }?;
+
+            return Ok(Self { exported_macros: macros.to_vec() });
+        }
+
+        // if we reached this point, versions didn't match. in testing, we
+        // want that to panic - this could mean that the format of `rustc
+        // --version` no longer matches the format of the version string
+        // stored in the `.rustc` section, and we want to catch that in-tree
+        // with `x.py test`
+        if cfg!(test) {
+            panic!(
+                "sysroot ABI mismatch: dylib rustc version (read from .rustc section): {:?} != proc-macro-srv version (read from 'rustc --version'): {:?}",
+                info.version_string, crate::RUSTC_VERSION_STRING
+            );
+        }
+        Err(LoadProcMacroDylibError::AbiMismatch(info.version_string))
+    }
+
+    pub fn expand(
+        &self,
+        macro_name: &str,
+        macro_body: &tt::Subtree,
+        attributes: Option<&tt::Subtree>,
+    ) -> Result<tt::Subtree, crate::PanicMessage> {
+        let parsed_body = crate::server::TokenStream::with_subtree(macro_body.clone());
+
+        let parsed_attributes = attributes.map_or(crate::server::TokenStream::new(), |attr| {
+            crate::server::TokenStream::with_subtree(attr.clone())
+        });
+
+        for proc_macro in &self.exported_macros {
+            match proc_macro {
+                proc_macro::bridge::client::ProcMacro::CustomDerive {
+                    trait_name, client, ..
+                } if *trait_name == macro_name => {
+                    let res = client.run(
+                        &proc_macro::bridge::server::SameThread,
+                        crate::server::RustAnalyzer::default(),
+                        parsed_body,
+                        true,
+                    );
+                    return res.map(|it| it.into_subtree()).map_err(crate::PanicMessage::from);
+                }
+                proc_macro::bridge::client::ProcMacro::Bang { name, client }
+                    if *name == macro_name =>
+                {
+                    let res = client.run(
+                        &proc_macro::bridge::server::SameThread,
+                        crate::server::RustAnalyzer::default(),
+                        parsed_body,
+                        true,
+                    );
+                    return res.map(|it| it.into_subtree()).map_err(crate::PanicMessage::from);
+                }
+                proc_macro::bridge::client::ProcMacro::Attr { name, client }
+                    if *name == macro_name =>
+                {
+                    let res = client.run(
+                        &proc_macro::bridge::server::SameThread,
+                        crate::server::RustAnalyzer::default(),
+                        parsed_attributes,
+                        parsed_body,
+                        true,
+                    );
+                    return res.map(|it| it.into_subtree()).map_err(crate::PanicMessage::from);
+                }
+                _ => continue,
+            }
+        }
+
+        Err(proc_macro::bridge::PanicMessage::String("Nothing to expand".to_string()).into())
+    }
+
+    pub fn list_macros(&self) -> Vec<(String, ProcMacroKind)> {
+        self.exported_macros
+            .iter()
+            .map(|proc_macro| match proc_macro {
+                proc_macro::bridge::client::ProcMacro::CustomDerive { trait_name, .. } => {
+                    (trait_name.to_string(), ProcMacroKind::CustomDerive)
+                }
+                proc_macro::bridge::client::ProcMacro::Bang { name, .. } => {
+                    (name.to_string(), ProcMacroKind::FuncLike)
+                }
+                proc_macro::bridge::client::ProcMacro::Attr { name, .. } => {
+                    (name.to_string(), ProcMacroKind::Attr)
+                }
+            })
+            .collect()
+    }
+}
+
+#[test]
+fn test_version_check() {
+    let path = paths::AbsPathBuf::assert(crate::proc_macro_test_dylib_path());
+    let info = proc_macro_api::read_dylib_info(&path).unwrap();
+    assert_eq!(info.version_string, crate::RUSTC_VERSION_STRING);
+}