internal: remove unreasonable crate dependency

Proc macro expansion shouldn't know about salsa at all.

Cargo.lock

@@ -1120,7 +1120,6 @@ dependencies = [
 name = "proc_macro_api"
 version = "0.0.0"
 dependencies = [
- "base_db",
  "crossbeam-channel",
  "jod-thread",
  "log",

crates/proc_macro_api/Cargo.toml

@@ -15,17 +15,16 @@ log = "0.4.8"
 crossbeam-channel = "0.5.0"
 jod-thread = "0.1.1"
 memmap2 = "0.3.0"
-object = { version = "0.26", default-features = false, features = [
-    "std",
-    "read_core",
-    "elf",
-    "macho",
-    "pe",
-] }
 snap = "1.0"
 
 paths = { path = "../paths", version = "0.0.0" }
 tt = { path = "../tt", version = "0.0.0" }
-base_db = { path = "../base_db", version = "0.0.0" }
 stdx = { path = "../stdx", version = "0.0.0" }
 profile = { path = "../profile", version = "0.0.0" }
+# Intentionally *not* depend on anything salsa-related
+# base_db = { path = "../base_db", version = "0.0.0" }
+
+[dependencies.object]
+version = "0.26"
+default-features = false
+features = [ "std", "read_core", "elf", "macho", "pe" ]

crates/proc_macro_api/src/lib.rs

@@ -10,7 +10,6 @@ mod process;
 mod rpc;
 mod version;
 
-use base_db::{Env, ProcMacro};
 use paths::{AbsPath, AbsPathBuf};
 use std::{
     ffi::OsStr,
@@ -26,34 +25,44 @@ pub use rpc::{ExpansionResult, ExpansionTask, ListMacrosResult, ListMacrosTask,
 pub use version::{read_dylib_info, RustCInfo};
 
 #[derive(Debug, Clone)]
-struct ProcMacroProcessExpander {
+pub struct ProcMacroProcessExpander {
     process: Arc<Mutex<ProcMacroProcessSrv>>,
     dylib_path: AbsPathBuf,
     name: SmolStr,
+    kind: ProcMacroKind,
 }
 
 impl Eq for ProcMacroProcessExpander {}
 impl PartialEq for ProcMacroProcessExpander {
     fn eq(&self, other: &Self) -> bool {
         self.name == other.name
+            && self.kind == other.kind
             && self.dylib_path == other.dylib_path
             && Arc::ptr_eq(&self.process, &other.process)
     }
 }
 
-impl base_db::ProcMacroExpander for ProcMacroProcessExpander {
-    fn expand(
+impl ProcMacroProcessExpander {
+    pub fn name(&self) -> &str {
+        &self.name
+    }
+
+    pub fn kind(&self) -> ProcMacroKind {
+        self.kind
+    }
+
+    pub fn expand(
         &self,
         subtree: &Subtree,
         attr: Option<&Subtree>,
-        env: &Env,
+        env: Vec<(String, String)>,
     ) -> Result<Subtree, tt::ExpansionError> {
         let task = ExpansionTask {
             macro_body: subtree.clone(),
             macro_name: self.name.to_string(),
             attributes: attr.cloned(),
             lib: self.dylib_path.to_path_buf(),
-            env: env.iter().map(|(k, v)| (k.to_string(), v.to_string())).collect(),
+            env,
         };
 
         let result: ExpansionResult = self
@@ -86,7 +95,7 @@ impl ProcMacroClient {
         Ok(ProcMacroClient { process: Arc::new(Mutex::new(process)) })
     }
 
-    pub fn by_dylib_path(&self, dylib_path: &AbsPath) -> Vec<ProcMacro> {
+    pub fn by_dylib_path(&self, dylib_path: &AbsPath) -> Vec<ProcMacroProcessExpander> {
         let _p = profile::span("ProcMacroClient::by_dylib_path");
         match version::read_dylib_info(dylib_path) {
             Ok(info) => {
@@ -118,20 +127,11 @@ impl ProcMacroClient {
 
         macros
             .into_iter()
-            .map(|(name, kind)| {
-                let name = SmolStr::new(&name);
-                let kind = match kind {
-                    ProcMacroKind::CustomDerive => base_db::ProcMacroKind::CustomDerive,
-                    ProcMacroKind::FuncLike => base_db::ProcMacroKind::FuncLike,
-                    ProcMacroKind::Attr => base_db::ProcMacroKind::Attr,
-                };
-                let expander = Arc::new(ProcMacroProcessExpander {
-                    process: self.process.clone(),
-                    name: name.clone(),
-                    dylib_path: dylib_path.to_path_buf(),
-                });
-
-                ProcMacro { name, kind, expander }
+            .map(|(name, kind)| ProcMacroProcessExpander {
+                process: self.process.clone(),
+                name: name.into(),
+                kind,
+                dylib_path: dylib_path.to_path_buf(),
             })
             .collect()
     }

crates/rust-analyzer/Cargo.toml

@@ -52,6 +52,7 @@ vfs = { path = "../vfs", version = "0.0.0" }
 vfs-notify = { path = "../vfs-notify", version = "0.0.0" }
 cfg = { path = "../cfg", version = "0.0.0" }
 toolchain = { path = "../toolchain", version = "0.0.0" }
+tt = { path = "../tt", version = "0.0.0" }
 proc_macro_api = { path = "../proc_macro_api", version = "0.0.0" }
 
 # This should only be used in CLI

crates/rust-analyzer/src/cli/load_cargo.rs

@@ -11,7 +11,7 @@ use proc_macro_api::ProcMacroClient;
 use project_model::{CargoConfig, ProjectManifest, ProjectWorkspace, WorkspaceBuildScripts};
 use vfs::{loader::Handle, AbsPath, AbsPathBuf};
 
-use crate::reload::{ProjectFolders, SourceRootConfig};
+use crate::reload::{load_proc_macro, ProjectFolders, SourceRootConfig};
 
 // Note: Since this type is used by external tools that use rust-analyzer as a library
 // what otherwise would be `pub(crate)` has to be `pub` here instead.
@@ -69,9 +69,7 @@ pub fn load_workspace(
     });
 
     let crate_graph = ws.to_crate_graph(
-        &mut |path: &AbsPath| {
-            proc_macro_client.as_ref().map(|it| it.by_dylib_path(path)).unwrap_or_default()
-        },
+        &mut |path: &AbsPath| load_proc_macro(proc_macro_client.as_ref(), path),
         &mut |path: &AbsPath| {
             let contents = loader.load_sync(path);
             let path = vfs::VfsPath::from(path.to_path_buf());

crates/rust-analyzer/src/reload.rs

@@ -4,7 +4,9 @@ use std::{mem, sync::Arc};
 use flycheck::{FlycheckConfig, FlycheckHandle};
 use hir::db::DefDatabase;
 use ide::Change;
-use ide_db::base_db::{CrateGraph, SourceRoot, VfsPath};
+use ide_db::base_db::{
+    CrateGraph, Env, ProcMacro, ProcMacroExpander, ProcMacroKind, SourceRoot, VfsPath,
+};
 use proc_macro_api::ProcMacroClient;
 use project_model::{ProjectWorkspace, WorkspaceBuildScripts};
 use vfs::{file_set::FileSetConfig, AbsPath, AbsPathBuf, ChangeKind};
@@ -398,9 +400,8 @@ impl GlobalState {
         // Create crate graph from all the workspaces
         let crate_graph = {
             let proc_macro_client = self.proc_macro_client.as_ref();
-            let mut load_proc_macro = move |path: &AbsPath| {
-                proc_macro_client.map(|it| it.by_dylib_path(path)).unwrap_or_default()
-            };
+            let mut load_proc_macro =
+                move |path: &AbsPath| load_proc_macro(proc_macro_client, path);
 
             let vfs = &mut self.vfs.write().0;
             let loader = &mut self.loader;
@@ -587,3 +588,38 @@ impl SourceRootConfig {
             .collect()
     }
 }
+
+pub(crate) fn load_proc_macro(client: Option<&ProcMacroClient>, path: &AbsPath) -> Vec<ProcMacro> {
+    return client
+        .map(|it| it.by_dylib_path(path))
+        .unwrap_or_default()
+        .into_iter()
+        .map(expander_to_proc_macro)
+        .collect();
+
+    fn expander_to_proc_macro(expander: proc_macro_api::ProcMacroProcessExpander) -> ProcMacro {
+        let name = expander.name().into();
+        let kind = match expander.kind() {
+            proc_macro_api::ProcMacroKind::CustomDerive => ProcMacroKind::CustomDerive,
+            proc_macro_api::ProcMacroKind::FuncLike => ProcMacroKind::FuncLike,
+            proc_macro_api::ProcMacroKind::Attr => ProcMacroKind::Attr,
+        };
+        let expander = Arc::new(Expander(expander));
+        ProcMacro { name, kind, expander }
+    }
+
+    #[derive(Debug)]
+    struct Expander(proc_macro_api::ProcMacroProcessExpander);
+
+    impl ProcMacroExpander for Expander {
+        fn expand(
+            &self,
+            subtree: &tt::Subtree,
+            attrs: Option<&tt::Subtree>,
+            env: &Env,
+        ) -> Result<tt::Subtree, tt::ExpansionError> {
+            let env = env.iter().map(|(k, v)| (k.to_string(), v.to_string())).collect();
+            self.0.expand(subtree, attrs, env)
+        }
+    }
+}