internal: Split serde derive feature into serde_derive usage

Ideally we'd not have any dependency pull in the derive feature for faster build times, once that is the case this change would have an actual effect.
See https://github.com/matklad/macro-dep-test/blob/master/README.md for context.

crates/paths/Cargo.toml

@@ -14,10 +14,9 @@ doctest = false
 
 [dependencies]
 camino.workspace = true
-serde = { workspace = true, optional = true }
 
 [features]
-serde1 = ["camino/serde1", "dep:serde"]
+serde1 = ["camino/serde1"]
 
 [lints]
 workspace = true

crates/proc-macro-api/Cargo.toml

@@ -14,6 +14,7 @@ doctest = false
 
 [dependencies]
 serde.workspace = true
+serde_derive.workspace = true
 serde_json = { workspace = true, features = ["unbounded_depth"] }
 tracing.workspace = true
 rustc-hash.workspace = true

crates/proc-macro-api/src/msg.rs

@@ -4,7 +4,8 @@ pub(crate) mod flat;
 use std::io::{self, BufRead, Write};
 
 use paths::Utf8PathBuf;
-use serde::{de::DeserializeOwned, Deserialize, Serialize};
+use serde::de::DeserializeOwned;
+use serde_derive::{Deserialize, Serialize};
 
 use crate::ProcMacroKind;
 
@@ -123,7 +124,7 @@ impl ExpnGlobals {
     }
 }
 
-pub trait Message: Serialize + DeserializeOwned {
+pub trait Message: serde::Serialize + DeserializeOwned {
     fn read<R: BufRead>(
         from_proto: ProtocolRead<R>,
         inp: &mut R,

crates/proc-macro-api/src/msg/flat.rs

@@ -39,7 +39,7 @@ use std::collections::VecDeque;
 
 use intern::Symbol;
 use rustc_hash::FxHashMap;
-use serde::{Deserialize, Serialize};
+use serde_derive::{Deserialize, Serialize};
 use span::{EditionedFileId, ErasedFileAstId, Span, SpanAnchor, SyntaxContextId, TextRange};
 
 use crate::msg::EXTENDED_LEAF_DATA;

crates/project-model/Cargo.toml

@@ -19,6 +19,7 @@ rustc-hash.workspace = true
 semver.workspace = true
 serde_json.workspace = true
 serde.workspace = true
+serde_derive.workspace = true
 tracing.workspace = true
 triomphe.workspace = true
 la-arena.workspace = true

crates/project-model/src/build_dependencies.rs

@@ -15,7 +15,7 @@ use itertools::Itertools;
 use la_arena::ArenaMap;
 use paths::{AbsPath, AbsPathBuf, Utf8PathBuf};
 use rustc_hash::{FxHashMap, FxHashSet};
-use serde::Deserialize;
+use serde::Deserialize as _;
 use toolchain::Tool;
 
 use crate::{

crates/project-model/src/cargo_workspace.rs

@@ -8,7 +8,7 @@ use cargo_metadata::{CargoOpt, MetadataCommand};
 use la_arena::{Arena, Idx};
 use paths::{AbsPath, AbsPathBuf, Utf8PathBuf};
 use rustc_hash::{FxHashMap, FxHashSet};
-use serde::Deserialize;
+use serde_derive::Deserialize;
 use serde_json::from_value;
 use span::Edition;
 use toolchain::Tool;

crates/ra-salsa/Cargo.toml

@@ -20,7 +20,7 @@ parking_lot = "0.12.1"
 rustc-hash = "2.0.0"
 smallvec = "1.0.0"
 oorandom = "11"
-triomphe = "0.1.11"
+triomphe.workspace = true
 itertools.workspace = true
 
 ra-salsa-macros = { version = "0.0.0", path = "ra-salsa-macros", package = "salsa-macros" }

crates/rust-analyzer/Cargo.toml

@@ -36,6 +36,7 @@ rayon.workspace = true
 rustc-hash.workspace = true
 serde_json = { workspace = true, features = ["preserve_order"] }
 serde.workspace = true
+serde_derive.workspace = true
 tenthash = "0.4.0"
 num_cpus = "1.15.0"
 mimalloc = { version = "0.1.30", default-features = false, optional = true }

crates/rust-analyzer/src/flycheck.rs

@@ -6,7 +6,8 @@ use std::{fmt, io, process::Command, time::Duration};
 use crossbeam_channel::{select_biased, unbounded, Receiver, Sender};
 use paths::{AbsPath, AbsPathBuf, Utf8PathBuf};
 use rustc_hash::FxHashMap;
-use serde::Deserialize;
+use serde::Deserialize as _;
+use serde_derive::Deserialize;
 
 pub(crate) use cargo_metadata::diagnostic::{
     Applicability, Diagnostic, DiagnosticCode, DiagnosticLevel, DiagnosticSpan,

crates/rust-analyzer/src/test_runner.rs

@@ -5,7 +5,8 @@ use std::process::Command;
 
 use crossbeam_channel::Sender;
 use paths::AbsPath;
-use serde::Deserialize;
+use serde::Deserialize as _;
+use serde_derive::Deserialize;
 use toolchain::Tool;
 
 use crate::{

crates/rust-analyzer/src/tracing/json.rs

@@ -54,7 +54,7 @@ where
     fn on_event(&self, _event: &Event<'_>, _ctx: Context<'_, S>) {}
 
     fn on_close(&self, id: Id, ctx: Context<'_, S>) {
-        #[derive(serde::Serialize)]
+        #[derive(serde_derive::Serialize)]
         struct JsonDataInner {
             name: &'static str,
             elapsed_ms: u128,

crates/span/src/lib.rs

@@ -262,8 +262,9 @@ pub struct MacroFileId {
 /// `MacroCallId` identifies a particular macro invocation, like
 /// `println!("Hello, {}", world)`.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub struct MacroCallId(ra_salsa::InternId);
+pub struct MacroCallId(InternId);
 
+#[cfg(feature = "ra-salsa")]
 impl ra_salsa::InternKey for MacroCallId {
     fn from_intern_id(v: ra_salsa::InternId) -> Self {
         MacroCallId(v)
@@ -362,6 +363,7 @@ mod intern_id_proxy {
     use std::fmt;
     use std::num::NonZeroU32;
 
+    #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
     pub(super) struct InternId {
         value: NonZeroU32,
     }