feat: Add config to replace specific proc-macros with dummy expanders

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

@@ -66,7 +66,8 @@ pub fn load_workspace(
     };
 
     let crate_graph = ws.to_crate_graph(
-        &mut |path: &AbsPath| load_proc_macro(proc_macro_client.as_ref(), path),
+        &Default::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/config.rs

@@ -301,6 +301,7 @@ config_data! {
         /// Internal config, path to proc-macro server executable (typically,
         /// this is rust-analyzer itself, but we override this in tests).
         procMacro_server: Option<PathBuf>          = "null",
+        procMacro_dummies: FxHashMap<Box<str>, Box<[Box<str>]>>          = "{}",
 
         /// Command to be executed instead of 'cargo' for runnables.
         runnables_overrideCargo: Option<String> = "null",
@@ -716,6 +717,9 @@ impl Config {
         };
         Some((path, vec!["proc-macro".into()]))
     }
+    pub fn dummy_replacements(&self) -> &FxHashMap<Box<str>, Box<[Box<str>]>> {
+        &self.data.procMacro_dummies
+    }
     pub fn expand_proc_attr_macros(&self) -> bool {
         self.data.experimental_procAttrMacros
     }

crates/rust-analyzer/src/reload.rs

@@ -10,6 +10,7 @@ use ide_db::base_db::{
 };
 use proc_macro_api::{MacroDylib, ProcMacroServer};
 use project_model::{ProjectWorkspace, WorkspaceBuildScripts};
+use syntax::SmolStr;
 use vfs::{file_set::FileSetConfig, AbsPath, AbsPathBuf, ChangeKind};
 
 use crate::{
@@ -290,6 +291,9 @@ impl GlobalState {
                     }
                 },
             };
+            self.analysis_host
+                .raw_database_mut()
+                .set_enable_proc_attr_macros(self.config.expand_proc_attr_macros());
         }
 
         let watch = match files_config.watcher {
@@ -306,8 +310,9 @@ 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| load_proc_macro(proc_macro_client, path);
+            let mut load_proc_macro = move |path: &AbsPath, dummy_replace: &_| {
+                load_proc_macro(proc_macro_client, path, dummy_replace)
+            };
 
             let vfs = &mut self.vfs.write().0;
             let loader = &mut self.loader;
@@ -328,7 +333,11 @@ impl GlobalState {
 
             let mut crate_graph = CrateGraph::default();
             for ws in self.workspaces.iter() {
-                crate_graph.extend(ws.to_crate_graph(&mut load_proc_macro, &mut load));
+                crate_graph.extend(ws.to_crate_graph(
+                    self.config.dummy_replacements(),
+                    &mut load_proc_macro,
+                    &mut load,
+                ));
             }
             crate_graph
         };
@@ -505,7 +514,11 @@ impl SourceRootConfig {
     }
 }
 
-pub(crate) fn load_proc_macro(client: Option<&ProcMacroServer>, path: &AbsPath) -> Vec<ProcMacro> {
+pub(crate) fn load_proc_macro(
+    client: Option<&ProcMacroServer>,
+    path: &AbsPath,
+    dummy_replace: &[Box<str>],
+) -> Vec<ProcMacro> {
     let dylib = match MacroDylib::new(path.to_path_buf()) {
         Ok(it) => it,
         Err(err) => {
@@ -532,17 +545,25 @@ pub(crate) fn load_proc_macro(client: Option<&ProcMacroServer>, path: &AbsPath)
                 Vec::new()
             }
         })
-        .map(expander_to_proc_macro)
+        .map(|expander| expander_to_proc_macro(expander, dummy_replace))
         .collect();
 
-    fn expander_to_proc_macro(expander: proc_macro_api::ProcMacro) -> ProcMacro {
-        let name = expander.name().into();
+    fn expander_to_proc_macro(
+        expander: proc_macro_api::ProcMacro,
+        dummy_replace: &[Box<str>],
+    ) -> ProcMacro {
+        let name = SmolStr::from(expander.name());
         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));
+        let expander: Arc<dyn ProcMacroExpander> =
+            if dummy_replace.iter().any(|replace| &**replace == name) {
+                Arc::new(DummyExpander)
+            } else {
+                Arc::new(Expander(expander))
+            };
         ProcMacro { name, kind, expander }
     }
 
@@ -564,6 +585,20 @@ pub(crate) fn load_proc_macro(client: Option<&ProcMacroServer>, path: &AbsPath)
             }
         }
     }
+
+    #[derive(Debug)]
+    struct DummyExpander;
+
+    impl ProcMacroExpander for DummyExpander {
+        fn expand(
+            &self,
+            subtree: &tt::Subtree,
+            _: Option<&tt::Subtree>,
+            _: &Env,
+        ) -> Result<tt::Subtree, ProcMacroExpansionError> {
+            Ok(subtree.clone())
+        }
+    }
 }
 
 pub(crate) fn should_refresh_for_change(path: &AbsPath, change_kind: ChangeKind) -> bool {