Show proc-macro loading errors in unresolved-proc-macro diagnostics

crates/base-db/src/fixture.rs

@@ -159,7 +159,7 @@ impl ChangeFixture {
                     meta.cfg.clone(),
                     meta.cfg,
                     meta.env,
-                    Default::default(),
+                    Ok(Vec::new()),
                     false,
                     origin,
                 );
@@ -194,7 +194,7 @@ impl ChangeFixture {
                 default_cfg.clone(),
                 default_cfg,
                 Env::default(),
-                Default::default(),
+                Ok(Vec::new()),
                 false,
                 CrateOrigin::CratesIo { repo: None },
             );
@@ -231,7 +231,7 @@ impl ChangeFixture {
                 CfgOptions::default(),
                 CfgOptions::default(),
                 Env::default(),
-                Vec::new(),
+                Ok(Vec::new()),
                 false,
                 CrateOrigin::Lang(LangCrateOrigin::Core),
             );
@@ -268,7 +268,7 @@ impl ChangeFixture {
                 CfgOptions::default(),
                 CfgOptions::default(),
                 Env::default(),
-                proc_macro,
+                Ok(proc_macro),
                 true,
                 CrateOrigin::CratesIo { repo: None },
             );

crates/base-db/src/input.rs

@@ -231,6 +231,8 @@ pub enum ProcMacroExpansionError {
     System(String),
 }
 
+pub type ProcMacroLoadResult = Result<Vec<ProcMacro>, String>;
+
 #[derive(Debug, Clone)]
 pub struct ProcMacro {
     pub name: SmolStr,
@@ -254,7 +256,7 @@ pub struct CrateData {
     pub potential_cfg_options: CfgOptions,
     pub env: Env,
     pub dependencies: Vec<Dependency>,
-    pub proc_macro: Vec<ProcMacro>,
+    pub proc_macro: ProcMacroLoadResult,
     pub origin: CrateOrigin,
     pub is_proc_macro: bool,
 }
@@ -300,19 +302,19 @@ impl Dependency {
 impl CrateGraph {
     pub fn add_crate_root(
         &mut self,
-        file_id: FileId,
+        root_file_id: FileId,
         edition: Edition,
         display_name: Option<CrateDisplayName>,
         version: Option<String>,
         cfg_options: CfgOptions,
         potential_cfg_options: CfgOptions,
         env: Env,
-        proc_macro: Vec<ProcMacro>,
+        proc_macro: ProcMacroLoadResult,
         is_proc_macro: bool,
         origin: CrateOrigin,
     ) -> CrateId {
         let data = CrateData {
-            root_file_id: file_id,
+            root_file_id,
             edition,
             version,
             display_name,
@@ -628,7 +630,7 @@ mod tests {
             CfgOptions::default(),
             CfgOptions::default(),
             Env::default(),
-            Default::default(),
+            Ok(Vec::new()),
             false,
             CrateOrigin::CratesIo { repo: None },
         );
@@ -640,7 +642,7 @@ mod tests {
             CfgOptions::default(),
             CfgOptions::default(),
             Env::default(),
-            Default::default(),
+            Ok(Vec::new()),
             false,
             CrateOrigin::CratesIo { repo: None },
         );
@@ -652,7 +654,7 @@ mod tests {
             CfgOptions::default(),
             CfgOptions::default(),
             Env::default(),
-            Default::default(),
+            Ok(Vec::new()),
             false,
             CrateOrigin::CratesIo { repo: None },
         );
@@ -678,7 +680,7 @@ mod tests {
             CfgOptions::default(),
             CfgOptions::default(),
             Env::default(),
-            Default::default(),
+            Ok(Vec::new()),
             false,
             CrateOrigin::CratesIo { repo: None },
         );
@@ -690,7 +692,7 @@ mod tests {
             CfgOptions::default(),
             CfgOptions::default(),
             Env::default(),
-            Default::default(),
+            Ok(Vec::new()),
             false,
             CrateOrigin::CratesIo { repo: None },
         );
@@ -713,7 +715,7 @@ mod tests {
             CfgOptions::default(),
             CfgOptions::default(),
             Env::default(),
-            Default::default(),
+            Ok(Vec::new()),
             false,
             CrateOrigin::CratesIo { repo: None },
         );
@@ -725,7 +727,7 @@ mod tests {
             CfgOptions::default(),
             CfgOptions::default(),
             Env::default(),
-            Default::default(),
+            Ok(Vec::new()),
             false,
             CrateOrigin::CratesIo { repo: None },
         );
@@ -737,7 +739,7 @@ mod tests {
             CfgOptions::default(),
             CfgOptions::default(),
             Env::default(),
-            Default::default(),
+            Ok(Vec::new()),
             false,
             CrateOrigin::CratesIo { repo: None },
         );
@@ -760,7 +762,7 @@ mod tests {
             CfgOptions::default(),
             CfgOptions::default(),
             Env::default(),
-            Default::default(),
+            Ok(Vec::new()),
             false,
             CrateOrigin::CratesIo { repo: None },
         );
@@ -772,7 +774,7 @@ mod tests {
             CfgOptions::default(),
             CfgOptions::default(),
             Env::default(),
-            Default::default(),
+            Ok(Vec::new()),
             false,
             CrateOrigin::CratesIo { repo: None },
         );

crates/base-db/src/lib.rs

@@ -13,7 +13,7 @@ pub use crate::{
     input::{
         CrateData, CrateDisplayName, CrateGraph, CrateId, CrateName, CrateOrigin, Dependency,
         Edition, Env, LangCrateOrigin, ProcMacro, ProcMacroExpander, ProcMacroExpansionError,
-        ProcMacroId, ProcMacroKind, SourceRoot, SourceRootId,
+        ProcMacroId, ProcMacroKind, ProcMacroLoadResult, SourceRoot, SourceRootId,
     },
 };
 pub use salsa::{self, Cancelled};

crates/hir-def/src/nameres.rs

@@ -103,6 +103,8 @@ pub struct DefMap {
     /// 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<SmolStr>,
@@ -273,6 +275,7 @@ impl DefMap {
             extern_prelude: FxHashMap::default(),
             exported_derives: FxHashMap::default(),
             fn_proc_macro_mapping: FxHashMap::default(),
+            proc_macro_loading_error: None,
             prelude: None,
             root,
             modules,
@@ -305,6 +308,9 @@ impl DefMap {
     pub fn fn_as_proc_macro(&self, id: FunctionId) -> Option<ProcMacroId> {
         self.fn_proc_macro_mapping.get(&id).copied()
     }
+    pub fn proc_macro_loading_error(&self) -> Option<&str> {
+        self.proc_macro_loading_error.as_deref()
+    }
 
     pub(crate) fn krate(&self) -> CrateId {
         self.krate
@@ -460,6 +466,7 @@ impl DefMap {
             registered_attrs,
             registered_tools,
             fn_proc_macro_mapping,
+            proc_macro_loading_error: _,
             block: _,
             edition: _,
             recursion_limit: _,

crates/hir-def/src/nameres/collector.rs

@@ -74,19 +74,26 @@ pub(super) fn collect_defs(db: &dyn DefDatabase, mut def_map: DefMap, tree_id: T
     }
 
     let cfg_options = &krate.cfg_options;
-    let proc_macros = krate
-        .proc_macro
-        .iter()
-        .enumerate()
-        .map(|(idx, it)| {
-            // FIXME: a hacky way to create a Name from string.
-            let name = tt::Ident { text: it.name.clone(), id: tt::TokenId::unspecified() };
-            (
-                name.as_name(),
-                ProcMacroExpander::new(def_map.krate, base_db::ProcMacroId(idx as u32)),
-            )
-        })
-        .collect();
+    let proc_macros = match &krate.proc_macro {
+        Ok(proc_macros) => {
+            proc_macros
+                .iter()
+                .enumerate()
+                .map(|(idx, it)| {
+                    // FIXME: a hacky way to create a Name from string.
+                    let name = tt::Ident { text: it.name.clone(), id: tt::TokenId::unspecified() };
+                    (
+                        name.as_name(),
+                        ProcMacroExpander::new(def_map.krate, base_db::ProcMacroId(idx as u32)),
+                    )
+                })
+                .collect()
+        }
+        Err(e) => {
+            def_map.proc_macro_loading_error = Some(e.clone().into_boxed_str());
+            Vec::new()
+        }
+    };
     let is_proc_macro = krate.is_proc_macro;
 
     let mut collector = DefCollector {
@@ -1128,7 +1135,19 @@ impl DefCollector<'_> {
 
                     let def = match resolver(path.clone()) {
                         Some(def) if def.is_attribute() => def,
-                        _ => return true,
+                        _ => {
+                            self.def_map.diagnostics.push(DefDiagnostic::unresolved_proc_macro(
+                                directive.module_id,
+                                MacroCallKind::Attr {
+                                    ast_id,
+                                    attr_args: Default::default(),
+                                    invoc_attr_index: attr.id.ast_index,
+                                    is_derive: false,
+                                },
+                                None,
+                            ));
+                            return true;
+                        }
                     };
                     if matches!(
                         def,
@@ -1232,6 +1251,7 @@ impl DefCollector<'_> {
                             self.def_map.diagnostics.push(DefDiagnostic::unresolved_proc_macro(
                                 directive.module_id,
                                 loc.kind,
+                                Some(loc.def.krate),
                             ));
 
                             return recollect_without(self);
@@ -1283,7 +1303,11 @@ impl DefCollector<'_> {
             let diag = match err {
                 hir_expand::ExpandError::UnresolvedProcMacro => {
                     // Missing proc macros are non-fatal, so they are handled specially.
-                    DefDiagnostic::unresolved_proc_macro(module_id, loc.kind.clone())
+                    DefDiagnostic::unresolved_proc_macro(
+                        module_id,
+                        loc.kind.clone(),
+                        Some(loc.def.krate),
+                    )
                 }
                 _ => DefDiagnostic::macro_error(module_id, loc.kind.clone(), err.to_string()),
             };

crates/hir-def/src/nameres/diagnostics.rs

@@ -1,5 +1,6 @@
 //! Diagnostics emitted during DefMap construction.
 
+use base_db::CrateId;
 use cfg::{CfgExpr, CfgOptions};
 use hir_expand::MacroCallKind;
 use la_arena::Idx;
@@ -23,7 +24,7 @@ pub enum DefDiagnosticKind {
 
     UnconfiguredCode { ast: AstId<ast::Item>, cfg: CfgExpr, opts: CfgOptions },
 
-    UnresolvedProcMacro { ast: MacroCallKind },
+    UnresolvedProcMacro { ast: MacroCallKind, krate: Option<CrateId> },
 
     UnresolvedMacroCall { ast: MacroCallKind, path: ModPath },
 
@@ -81,8 +82,12 @@ impl DefDiagnostic {
         Self { in_module: container, kind: DefDiagnosticKind::UnconfiguredCode { ast, cfg, opts } }
     }
 
-    pub(super) fn unresolved_proc_macro(container: LocalModuleId, ast: MacroCallKind) -> Self {
-        Self { in_module: container, kind: DefDiagnosticKind::UnresolvedProcMacro { ast } }
+    pub(super) fn unresolved_proc_macro(
+        container: LocalModuleId,
+        ast: MacroCallKind,
+        krate: Option<CrateId>,
+    ) -> Self {
+        Self { in_module: container, kind: DefDiagnosticKind::UnresolvedProcMacro { ast, krate } }
     }
 
     pub(super) fn macro_error(

crates/hir-expand/src/proc_macro.rs

@@ -34,7 +34,15 @@ impl ProcMacroExpander {
         match self.proc_macro_id {
             Some(id) => {
                 let krate_graph = db.crate_graph();
-                let proc_macro = match krate_graph[self.krate].proc_macro.get(id.0 as usize) {
+                let proc_macros = match &krate_graph[self.krate].proc_macro {
+                    Ok(proc_macros) => proc_macros,
+                    Err(e) => {
+                        return ExpandResult::only_err(ExpandError::Other(
+                            e.clone().into_boxed_str(),
+                        ))
+                    }
+                };
+                let proc_macro = match proc_macros.get(id.0 as usize) {
                     Some(proc_macro) => proc_macro,
                     None => {
                         return ExpandResult::only_err(ExpandError::Other(

crates/hir/src/diagnostics.rs

@@ -3,6 +3,7 @@
 //!
 //! This probably isn't the best way to do this -- ideally, diagnistics should
 //! be expressed in terms of hir types themselves.
+use base_db::CrateId;
 use cfg::{CfgExpr, CfgOptions};
 use either::Either;
 use hir_def::path::ModPath;
@@ -87,6 +88,8 @@ pub struct UnresolvedProcMacro {
     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: Option<CrateId>,
 }
 
 #[derive(Debug, Clone, Eq, PartialEq)]

crates/hir/src/lib.rs

@@ -627,7 +627,7 @@ fn emit_def_diagnostic(db: &dyn HirDatabase, acc: &mut Vec<AnyDiagnostic>, diag:
             );
         }
 
-        DefDiagnosticKind::UnresolvedProcMacro { ast } => {
+        DefDiagnosticKind::UnresolvedProcMacro { ast, krate } => {
             let (node, precise_location, macro_name, kind) = match ast {
                 MacroCallKind::FnLike { ast_id, .. } => {
                     let node = ast_id.to_node(db.upcast());
@@ -689,7 +689,10 @@ fn emit_def_diagnostic(db: &dyn HirDatabase, acc: &mut Vec<AnyDiagnostic>, diag:
                     )
                 }
             };
-            acc.push(UnresolvedProcMacro { node, precise_location, macro_name, kind }.into());
+            acc.push(
+                UnresolvedProcMacro { node, precise_location, macro_name, kind, krate: *krate }
+                    .into(),
+            );
         }
 
         DefDiagnosticKind::UnresolvedMacroCall { ast, path } => {
@@ -1163,6 +1166,7 @@ impl DefWithBody {
                         precise_location: None,
                         macro_name: None,
                         kind: MacroKind::ProcMacro,
+                        krate: None,
                     }
                     .into(),
                 ),