Internal: Cleanup proc-macro error handling

crates/base-db/src/input.rs

@@ -16,9 +16,7 @@ use span::{Edition, EditionedFileId};
 use triomphe::Arc;
 use vfs::{file_set::FileSet, AbsPathBuf, AnchoredPath, FileId, VfsPath};
 
-// Map from crate id to the name of the crate and path of the proc-macro. If the value is `None`,
+pub type ProcMacroPaths = FxHashMap<CrateId, Result<(String, AbsPathBuf), String>>;
-// then the crate for the proc-macro hasn't been build yet as the build data is missing.
-pub type ProcMacroPaths = FxHashMap<CrateId, Result<(Option<String>, AbsPathBuf), String>>;
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]
 pub struct SourceRootId(pub u32);

crates/hir-def/src/body.rs

@@ -10,7 +10,7 @@ use std::ops::{Deref, Index};
 
 use base_db::CrateId;
 use cfg::{CfgExpr, CfgOptions};
-use hir_expand::{name::Name, InFile};
+use hir_expand::{name::Name, ExpandError, InFile};
 use la_arena::{Arena, ArenaMap, Idx, RawIdx};
 use rustc_hash::FxHashMap;
 use smallvec::SmallVec;
@@ -115,8 +115,7 @@ pub struct SyntheticSyntax;
 #[derive(Debug, Eq, PartialEq)]
 pub enum BodyDiagnostic {
     InactiveCode { node: InFile<SyntaxNodePtr>, cfg: CfgExpr, opts: CfgOptions },
-    MacroError { node: InFile<AstPtr<ast::MacroCall>>, message: String },
+    MacroError { node: InFile<AstPtr<ast::MacroCall>>, err: ExpandError },
-    UnresolvedProcMacro { node: InFile<AstPtr<ast::MacroCall>>, krate: CrateId },
     UnresolvedMacroCall { node: InFile<AstPtr<ast::MacroCall>>, path: ModPath },
     UnreachableLabel { node: InFile<AstPtr<ast::Lifetime>>, name: Name },
     UndeclaredLabel { node: InFile<AstPtr<ast::Lifetime>>, name: Name },

crates/hir-def/src/body/lower.rs

@@ -7,7 +7,7 @@ use base_db::CrateId;
 use either::Either;
 use hir_expand::{
     name::{AsName, Name},
-    ExpandError, InFile,
+    InFile,
 };
 use intern::{sym, Interned, Symbol};
 use rustc_hash::FxHashMap;
@@ -992,21 +992,12 @@ impl ExprCollector<'_> {
             }
         };
         if record_diagnostics {
-            match &res.err {
+            if let Some(err) = res.err {
-                Some(ExpandError::UnresolvedProcMacro(krate)) => {
-                    self.source_map.diagnostics.push(BodyDiagnostic::UnresolvedProcMacro {
-                        node: InFile::new(outer_file, syntax_ptr),
-                        krate: *krate,
-                    });
-                }
-                Some(err) => {
                 self.source_map.diagnostics.push(BodyDiagnostic::MacroError {
                     node: InFile::new(outer_file, syntax_ptr),
-                        message: err.to_string(),
+                    err,
                 });
             }
-                None => {}
-            }
         }
 
         match res.value {

crates/hir-def/src/data.rs

@@ -657,22 +657,17 @@ impl<'a> AssocItemCollector<'a> {
                             // crate failed), skip expansion like we would if it was
                             // disabled. This is analogous to the handling in
                             // `DefCollector::collect_macros`.
-                            if exp.is_dummy() {
+                            if let Some(err) = exp.as_expand_error(self.module_id.krate) {
-                                self.diagnostics.push(DefDiagnostic::unresolved_proc_macro(
+                                self.diagnostics.push(DefDiagnostic::macro_error(
                                     self.module_id.local_id,
-                                    loc.kind,
+                                    ast_id,
-                                    loc.def.krate,
+                                    err,
                                 ));
-
-                                continue 'attrs;
-                            }
-                            if exp.is_disabled() {
                                 continue 'attrs;
                             }
                         }
 
                         self.macro_calls.push((ast_id, call_id));
-
                         let res =
                             self.expander.enter_expand_id::<ast::MacroItems>(self.db, call_id);
                         self.collect_macro_items(res);

crates/hir-def/src/expander.rs

@@ -179,7 +179,7 @@ impl Expander {
             value: match err {
                 // If proc-macro is disabled or unresolved, we want to expand to a missing expression
                 // instead of an empty tree which might end up in an empty block.
-                Some(ExpandError::UnresolvedProcMacro(_)) => None,
+                Some(ExpandError::MissingProcMacroExpander(_)) => None,
                 _ => (|| {
                     let parse = res.value.0.cast::<T>()?;
 

crates/hir-def/src/lib.rs

@@ -75,9 +75,7 @@ use base_db::{
     CrateId,
 };
 use hir_expand::{
-    builtin_attr_macro::BuiltinAttrExpander,
+    builtin::{BuiltinAttrExpander, BuiltinDeriveExpander, BuiltinFnLikeExpander, EagerExpander},
-    builtin_derive_macro::BuiltinDeriveExpander,
-    builtin_fn_macro::{BuiltinFnLikeExpander, EagerExpander},
     db::ExpandDatabase,
     eager::expand_eager_macro_input,
     impl_intern_lookup,

crates/hir-def/src/macro_expansion_tests/mod.rs

@@ -122,7 +122,7 @@ pub fn identity_when_valid(_attr: TokenStream, item: TokenStream) -> TokenStream
 
         let mut expn_text = String::new();
         if let Some(err) = exp.err {
-            format_to!(expn_text, "/* error: {} */", err);
+            format_to!(expn_text, "/* error: {} */", err.render_to_string(&db).0);
         }
         let (parse, token_map) = exp.value;
         if expect_errors {

crates/hir-def/src/nameres.rs

@@ -145,8 +145,6 @@ struct DefMapCrateData {
     /// 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<Symbol>,
@@ -169,7 +167,6 @@ impl DefMapCrateData {
             extern_prelude: FxIndexMap::default(),
             exported_derives: FxHashMap::default(),
             fn_proc_macro_mapping: FxHashMap::default(),
-            proc_macro_loading_error: None,
             registered_attrs: Vec::new(),
             registered_tools: PREDEFINED_TOOLS.iter().map(|it| Symbol::intern(it)).collect(),
             unstable_features: FxHashSet::default(),
@@ -189,7 +186,6 @@ impl DefMapCrateData {
             registered_attrs,
             registered_tools,
             unstable_features,
-            proc_macro_loading_error: _,
             rustc_coherence_is_core: _,
             no_core: _,
             no_std: _,
@@ -474,10 +470,6 @@ impl DefMap {
         self.data.fn_proc_macro_mapping.get(&id).copied()
     }
 
-    pub fn proc_macro_loading_error(&self) -> Option<&str> {
-        self.data.proc_macro_loading_error.as_deref()
-    }
-
     pub fn krate(&self) -> CrateId {
         self.krate
     }

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

@@ -10,9 +10,7 @@ use cfg::{CfgExpr, CfgOptions};
 use either::Either;
 use hir_expand::{
     attrs::{Attr, AttrId},
-    builtin_attr_macro::find_builtin_attr,
+    builtin::{find_builtin_attr, find_builtin_derive, find_builtin_macro},
-    builtin_derive_macro::find_builtin_derive,
-    builtin_fn_macro::find_builtin_macro,
     name::{AsName, Name},
     proc_macro::CustomProcMacroExpander,
     ExpandTo, HirFileId, InFile, MacroCallId, MacroCallKind, MacroDefId, MacroDefKind,
@@ -76,34 +74,11 @@ pub(super) fn collect_defs(db: &dyn DefDatabase, def_map: DefMap, tree_id: TreeI
     }
 
     let proc_macros = if krate.is_proc_macro {
-        match db.proc_macros().get(&def_map.krate) {
+        db.proc_macros()
-            Some(Ok(proc_macros)) => Ok({
+            .for_crate(def_map.krate, db.syntax_context(tree_id.file_id()))
-                let ctx = db.syntax_context(tree_id.file_id());
+            .unwrap_or_default()
-                proc_macros
-                    .iter()
-                    .enumerate()
-                    .map(|(idx, it)| {
-                        let name = Name::new_symbol(it.name.clone(), ctx);
-                        (
-                            name,
-                            if !db.expand_proc_attr_macros() {
-                                CustomProcMacroExpander::dummy()
-                            } else if it.disabled {
-                                CustomProcMacroExpander::disabled()
     } else {
-                                CustomProcMacroExpander::new(
+        Default::default()
-                                    hir_expand::proc_macro::ProcMacroId::new(idx as u32),
-                                )
-                            },
-                        )
-                    })
-                    .collect()
-            }),
-            Some(Err(e)) => Err(e.clone().into_boxed_str()),
-            None => Err("No proc-macros present for crate".to_owned().into_boxed_str()),
-        }
-    } else {
-        Ok(vec![])
     };
 
     let mut collector = DefCollector {
@@ -252,10 +227,10 @@ struct DefCollector<'a> {
     mod_dirs: FxHashMap<LocalModuleId, ModDir>,
     cfg_options: &'a CfgOptions,
     /// List of procedural macros defined by this crate. This is read from the dynamic library
-    /// built by the build system, and is the list of proc. macros we can actually expand. It is
+    /// built by the build system, and is the list of proc-macros we can actually expand. It is
-    /// empty when proc. macro support is disabled (in which case we still do name resolution for
+    /// empty when proc-macro support is disabled (in which case we still do name resolution for
-    /// them).
+    /// them). The bool signals whether the proc-macro has been explicitly disabled for name-resolution.
-    proc_macros: Result<Vec<(Name, CustomProcMacroExpander)>, Box<str>>,
+    proc_macros: Box<[(Name, CustomProcMacroExpander, bool)]>,
     is_proc_macro: bool,
     from_glob_import: PerNsGlobImports,
     /// If we fail to resolve an attribute on a `ModItem`, we fall back to ignoring the attribute.
@@ -278,10 +253,6 @@ impl DefCollector<'_> {
         let attrs = item_tree.top_level_attrs(self.db, self.def_map.krate);
         let crate_data = Arc::get_mut(&mut self.def_map.data).unwrap();
 
-        if let Err(e) = &self.proc_macros {
-            crate_data.proc_macro_loading_error = Some(e.clone());
-        }
-
         let mut process = true;
 
         // Process other crate-level attributes.
@@ -608,10 +579,16 @@ impl DefCollector<'_> {
         fn_id: FunctionId,
     ) {
         let kind = def.kind.to_basedb_kind();
-        let (expander, kind) =
+        let (expander, kind) = match self.proc_macros.iter().find(|(n, _, _)| n == &def.name) {
-            match self.proc_macros.as_ref().map(|it| it.iter().find(|(n, _)| n == &def.name)) {
+            Some(_)
-                Ok(Some(&(_, expander))) => (expander, kind),
+                if kind == hir_expand::proc_macro::ProcMacroKind::Attr
-                _ => (CustomProcMacroExpander::dummy(), kind),
+                    && !self.db.expand_proc_attr_macros() =>
+            {
+                (CustomProcMacroExpander::disabled_proc_attr(), kind)
+            }
+            Some(&(_, _, true)) => (CustomProcMacroExpander::disabled(), kind),
+            Some(&(_, expander, false)) => (expander, kind),
+            None => (CustomProcMacroExpander::missing_expander(), kind),
         };
 
         let proc_macro_id = ProcMacroLoc {
@@ -1338,25 +1315,22 @@ impl DefCollector<'_> {
                         return recollect_without(self);
                     }
 
-                    let call_id = call_id();
                     if let MacroDefKind::ProcMacro(_, exp, _) = def.kind {
                         // If there's no expander for the proc macro (e.g.
                         // because proc macros are disabled, or building the
                         // proc macro crate failed), report this and skip
                         // expansion like we would if it was disabled
-                        if exp.is_dummy() {
+                        if let Some(err) = exp.as_expand_error(def.krate) {
-                            self.def_map.diagnostics.push(DefDiagnostic::unresolved_proc_macro(
+                            self.def_map.diagnostics.push(DefDiagnostic::macro_error(
                                 directive.module_id,
-                                self.db.lookup_intern_macro_call(call_id).kind,
+                                ast_id,
-                                def.krate,
+                                err,
                             ));
                             return recollect_without(self);
                         }
-                        if exp.is_disabled() {
-                            return recollect_without(self);
-                        }
                     }
 
+                    let call_id = call_id();
                     self.def_map.modules[directive.module_id]
                         .scope
                         .add_attr_macro_invoc(ast_id, call_id);
@@ -1395,7 +1369,6 @@ impl DefCollector<'_> {
         }
         let file_id = macro_call_id.as_file();
 
-        // Then, fetch and process the item tree. This will reuse the expansion result from above.
         let item_tree = self.db.file_item_tree(file_id);
 
         let mod_dir = if macro_call_id.as_macro_file().is_include_macro(self.db.upcast()) {
@@ -2433,7 +2406,7 @@ mod tests {
             unresolved_macros: Vec::new(),
             mod_dirs: FxHashMap::default(),
             cfg_options: &CfgOptions::default(),
-            proc_macros: Ok(vec![]),
+            proc_macros: Default::default(),
             from_glob_import: Default::default(),
             skip_attrs: Default::default(),
             is_proc_macro: false,

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

@@ -2,9 +2,8 @@
 
 use std::ops::Not;
 
-use base_db::CrateId;
 use cfg::{CfgExpr, CfgOptions};
-use hir_expand::{attrs::AttrId, MacroCallKind};
+use hir_expand::{attrs::AttrId, ExpandError, MacroCallKind};
 use la_arena::Idx;
 use syntax::ast;
 
@@ -17,48 +16,16 @@ use crate::{
 
 #[derive(Debug, PartialEq, Eq)]
 pub enum DefDiagnosticKind {
-    UnresolvedModule {
+    UnresolvedModule { ast: AstId<ast::Module>, candidates: Box<[String]> },
-        ast: AstId<ast::Module>,
+    UnresolvedExternCrate { ast: AstId<ast::ExternCrate> },
-        candidates: Box<[String]>,
+    UnresolvedImport { id: ItemTreeId<item_tree::Use>, index: Idx<ast::UseTree> },
-    },
+    UnconfiguredCode { tree: TreeId, item: AttrOwner, cfg: CfgExpr, opts: CfgOptions },
-    UnresolvedExternCrate {
+    UnresolvedMacroCall { ast: MacroCallKind, path: ModPath },
-        ast: AstId<ast::ExternCrate>,
+    UnimplementedBuiltinMacro { ast: AstId<ast::Macro> },
-    },
+    InvalidDeriveTarget { ast: AstId<ast::Item>, id: usize },
-    UnresolvedImport {
+    MalformedDerive { ast: AstId<ast::Adt>, id: usize },
-        id: ItemTreeId<item_tree::Use>,
+    MacroDefError { ast: AstId<ast::Macro>, message: String },
-        index: Idx<ast::UseTree>,
+    MacroError { ast: AstId<ast::Item>, err: ExpandError },
-    },
-    UnconfiguredCode {
-        tree: TreeId,
-        item: AttrOwner,
-        cfg: CfgExpr,
-        opts: CfgOptions,
-    },
-    /// A proc-macro that is lacking an expander, this might be due to build scripts not yet having
-    /// run or proc-macro expansion being disabled.
-    UnresolvedProcMacro {
-        ast: MacroCallKind,
-        krate: CrateId,
-    },
-    UnresolvedMacroCall {
-        ast: MacroCallKind,
-        path: ModPath,
-    },
-    UnimplementedBuiltinMacro {
-        ast: AstId<ast::Macro>,
-    },
-    InvalidDeriveTarget {
-        ast: AstId<ast::Item>,
-        id: usize,
-    },
-    MalformedDerive {
-        ast: AstId<ast::Adt>,
-        id: usize,
-    },
-    MacroDefError {
-        ast: AstId<ast::Macro>,
-        message: String,
-    },
 }
 
 #[derive(Clone, Debug, PartialEq, Eq)]
@@ -115,6 +82,10 @@ impl DefDiagnostic {
         Self { in_module: container, kind: DefDiagnosticKind::UnresolvedImport { id, index } }
     }
 
+    pub fn macro_error(container: LocalModuleId, ast: AstId<ast::Item>, err: ExpandError) -> Self {
+        Self { in_module: container, kind: DefDiagnosticKind::MacroError { ast, err } }
+    }
+
     pub fn unconfigured_code(
         container: LocalModuleId,
         tree: TreeId,
@@ -128,14 +99,6 @@ impl DefDiagnostic {
         }
     }
 
-    pub fn unresolved_proc_macro(
-        container: LocalModuleId,
-        ast: MacroCallKind,
-        krate: CrateId,
-    ) -> Self {
-        Self { in_module: container, kind: DefDiagnosticKind::UnresolvedProcMacro { ast, krate } }
-    }
-
     // FIXME: Whats the difference between this and unresolved_proc_macro
     pub(crate) fn unresolved_macro_call(
         container: LocalModuleId,

crates/hir-expand/src/builtin.rs

@@ -0,0 +1,14 @@
+#[macro_use]
+mod quote;
+
+mod attr_macro;
+mod derive_macro;
+mod fn_macro;
+
+pub use self::{
+    attr_macro::{find_builtin_attr, pseudo_derive_attr_expansion, BuiltinAttrExpander},
+    derive_macro::{find_builtin_derive, BuiltinDeriveExpander},
+    fn_macro::{
+        find_builtin_macro, include_input_to_file_id, BuiltinFnLikeExpander, EagerExpander,
+    },
+};

crates/hir-expand/src/builtin/derive_macro.rs

@@ -9,18 +9,18 @@ use stdx::never;
 use tracing::debug;
 
 use crate::{
+    builtin::quote::{dollar_crate, quote},
+    db::ExpandDatabase,
     hygiene::span_with_def_site_ctxt,
+    name,
     name::{AsName, Name},
-    quote::dollar_crate,
     span_map::ExpansionSpanMap,
-    tt,
+    tt, ExpandError, ExpandResult,
 };
 use syntax::ast::{
     self, AstNode, FieldList, HasAttrs, HasGenericParams, HasModuleItem, HasName, HasTypeBounds,
 };
 
-use crate::{db::ExpandDatabase, name, quote, ExpandError, ExpandResult};
-
 macro_rules! register_builtin {
     ( $($trait:ident => $expand:ident),* ) => {
         #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]

crates/hir-expand/src/builtin/fn_macro.rs

@@ -13,10 +13,10 @@ use syntax::{
 };
 
 use crate::{
+    builtin::quote::{dollar_crate, quote},
     db::ExpandDatabase,
     hygiene::{span_with_call_site_ctxt, span_with_def_site_ctxt},
-    name, quote,
+    name,
-    quote::dollar_crate,
     tt::{self, DelimSpan},
     ExpandError, ExpandResult, HirFileIdExt, Lookup as _, MacroCallId,
 };
@@ -145,7 +145,7 @@ register_builtin! {
 }
 
 fn mk_pound(span: Span) -> tt::Subtree {
-    crate::quote::IntoTt::to_subtree(
+    crate::builtin::quote::IntoTt::to_subtree(
         vec![crate::tt::Leaf::Punct(crate::tt::Punct {
             char: '#',
             spacing: crate::tt::Spacing::Alone,

crates/hir-expand/src/builtin/quote.rs

@@ -17,22 +17,21 @@ pub(crate) fn dollar_crate(span: Span) -> tt::Ident<Span> {
 // 2. #()* pattern repetition not supported now
 //    * But we can do it manually, see `test_quote_derive_copy_hack`
 #[doc(hidden)]
-#[macro_export]
+macro_rules! quote_impl__ {
-macro_rules! __quote {
     ($span:ident) => {
         Vec::<$crate::tt::TokenTree>::new()
     };
 
     ( @SUBTREE($span:ident) $delim:ident $($tt:tt)* ) => {
         {
-            let children = $crate::__quote!($span $($tt)*);
+            let children = $crate::builtin::quote::__quote!($span $($tt)*);
             $crate::tt::Subtree {
                 delimiter: crate::tt::Delimiter {
                     kind: crate::tt::DelimiterKind::$delim,
                     open: $span,
                     close: $span,
                 },
-                token_trees: $crate::quote::IntoTt::to_tokens(children).into_boxed_slice(),
+                token_trees: $crate::builtin::quote::IntoTt::to_tokens(children).into_boxed_slice(),
             }
         }
     };
@@ -69,9 +68,9 @@ macro_rules! __quote {
     // hash variable
     ($span:ident # $first:ident $($tail:tt)* ) => {
         {
-            let token = $crate::quote::ToTokenTree::to_token($first, $span);
+            let token = $crate::builtin::quote::ToTokenTree::to_token($first, $span);
             let mut tokens = vec![token.into()];
-            let mut tail_tokens = $crate::quote::IntoTt::to_tokens($crate::__quote!($span $($tail)*));
+            let mut tail_tokens = $crate::builtin::quote::IntoTt::to_tokens($crate::builtin::quote::__quote!($span $($tail)*));
             tokens.append(&mut tail_tokens);
             tokens
         }
@@ -79,22 +78,22 @@ macro_rules! __quote {
 
     ($span:ident ## $first:ident $($tail:tt)* ) => {
         {
-            let mut tokens = $first.into_iter().map(|it| $crate::quote::ToTokenTree::to_token(it, $span)).collect::<Vec<crate::tt::TokenTree>>();
+            let mut tokens = $first.into_iter().map(|it| $crate::builtin::quote::ToTokenTree::to_token(it, $span)).collect::<Vec<crate::tt::TokenTree>>();
-            let mut tail_tokens = $crate::quote::IntoTt::to_tokens($crate::__quote!($span $($tail)*));
+            let mut tail_tokens = $crate::builtin::quote::IntoTt::to_tokens($crate::builtin::quote::__quote!($span $($tail)*));
             tokens.append(&mut tail_tokens);
             tokens
         }
     };
 
     // Brace
-    ($span:ident  { $($tt:tt)* } ) => { $crate::__quote!(@SUBTREE($span) Brace $($tt)*) };
+    ($span:ident  { $($tt:tt)* } ) => { $crate::builtin::quote::__quote!(@SUBTREE($span) Brace $($tt)*) };
     // Bracket
-    ($span:ident  [ $($tt:tt)* ] ) => { $crate::__quote!(@SUBTREE($span) Bracket $($tt)*) };
+    ($span:ident  [ $($tt:tt)* ] ) => { $crate::builtin::quote::__quote!(@SUBTREE($span) Bracket $($tt)*) };
     // Parenthesis
-    ($span:ident  ( $($tt:tt)* ) ) => { $crate::__quote!(@SUBTREE($span) Parenthesis $($tt)*) };
+    ($span:ident  ( $($tt:tt)* ) ) => { $crate::builtin::quote::__quote!(@SUBTREE($span) Parenthesis $($tt)*) };
 
     // Literal
-    ($span:ident $tt:literal ) => { vec![$crate::quote::ToTokenTree::to_token($tt, $span).into()] };
+    ($span:ident $tt:literal ) => { vec![$crate::builtin::quote::ToTokenTree::to_token($tt, $span).into()] };
     // Ident
     ($span:ident $tt:ident ) => {
         vec![ {
@@ -108,36 +107,37 @@ macro_rules! __quote {
 
     // Puncts
     // FIXME: Not all puncts are handled
-    ($span:ident -> ) => {$crate::__quote!(@PUNCT($span) '-', '>')};
+    ($span:ident -> ) => {$crate::builtin::quote::__quote!(@PUNCT($span) '-', '>')};
-    ($span:ident & ) => {$crate::__quote!(@PUNCT($span) '&')};
+    ($span:ident & ) => {$crate::builtin::quote::__quote!(@PUNCT($span) '&')};
-    ($span:ident , ) => {$crate::__quote!(@PUNCT($span) ',')};
+    ($span:ident , ) => {$crate::builtin::quote::__quote!(@PUNCT($span) ',')};
-    ($span:ident : ) => {$crate::__quote!(@PUNCT($span) ':')};
+    ($span:ident : ) => {$crate::builtin::quote::__quote!(@PUNCT($span) ':')};
-    ($span:ident ; ) => {$crate::__quote!(@PUNCT($span) ';')};
+    ($span:ident ; ) => {$crate::builtin::quote::__quote!(@PUNCT($span) ';')};
-    ($span:ident :: ) => {$crate::__quote!(@PUNCT($span) ':', ':')};
+    ($span:ident :: ) => {$crate::builtin::quote::__quote!(@PUNCT($span) ':', ':')};
-    ($span:ident . ) => {$crate::__quote!(@PUNCT($span) '.')};
+    ($span:ident . ) => {$crate::builtin::quote::__quote!(@PUNCT($span) '.')};
-    ($span:ident < ) => {$crate::__quote!(@PUNCT($span) '<')};
+    ($span:ident < ) => {$crate::builtin::quote::__quote!(@PUNCT($span) '<')};
-    ($span:ident > ) => {$crate::__quote!(@PUNCT($span) '>')};
+    ($span:ident > ) => {$crate::builtin::quote::__quote!(@PUNCT($span) '>')};
-    ($span:ident ! ) => {$crate::__quote!(@PUNCT($span) '!')};
+    ($span:ident ! ) => {$crate::builtin::quote::__quote!(@PUNCT($span) '!')};
 
     ($span:ident $first:tt $($tail:tt)+ ) => {
         {
-            let mut tokens = $crate::quote::IntoTt::to_tokens($crate::__quote!($span $first ));
+            let mut tokens = $crate::builtin::quote::IntoTt::to_tokens($crate::builtin::quote::__quote!($span $first ));
-            let mut tail_tokens = $crate::quote::IntoTt::to_tokens($crate::__quote!($span $($tail)*));
+            let mut tail_tokens = $crate::builtin::quote::IntoTt::to_tokens($crate::builtin::quote::__quote!($span $($tail)*));
 
             tokens.append(&mut tail_tokens);
             tokens
         }
     };
 }
+pub(super) use quote_impl__ as __quote;
 
 /// FIXME:
 /// It probably should implement in proc-macro
-#[macro_export]
+macro_rules! quote_impl {
-macro_rules! quote {
     ($span:ident=> $($tt:tt)* ) => {
-        $crate::quote::IntoTt::to_subtree($crate::__quote!($span $($tt)*), $span)
+        $crate::builtin::quote::IntoTt::to_subtree($crate::builtin::quote::__quote!($span $($tt)*), $span)
     }
 }
+pub(super) use quote_impl as quote;
 
 pub(crate) trait IntoTt {
     fn to_subtree(self, span: Span) -> crate::tt::Subtree;
@@ -232,6 +232,8 @@ mod tests {
     use span::{SpanAnchor, SyntaxContextId, ROOT_ERASED_FILE_AST_ID};
     use syntax::{TextRange, TextSize};
 
+    use super::quote;
+
     const DUMMY: tt::Span = tt::Span {
         range: TextRange::empty(TextSize::new(0)),
         anchor: SpanAnchor {

crates/hir-expand/src/change.rs

@@ -25,8 +25,7 @@ impl ChangeWithProcMacros {
 
     pub fn apply(self, db: &mut (impl ExpandDatabase + SourceDatabaseExt)) {
         self.source_change.apply(db);
-        if let Some(mut proc_macros) = self.proc_macros {
+        if let Some(proc_macros) = self.proc_macros {
-            proc_macros.shrink_to_fit();
             db.set_proc_macros_with_durability(Arc::new(proc_macros), Durability::HIGH);
         }
         if let Some(target_data_layouts) = self.target_data_layouts {

crates/hir-expand/src/db.rs

@@ -11,8 +11,7 @@ use triomphe::Arc;
 
 use crate::{
     attrs::{collect_attrs, AttrId},
-    builtin_attr_macro::pseudo_derive_attr_expansion,
+    builtin::pseudo_derive_attr_expansion,
-    builtin_fn_macro::EagerExpander,
     cfg_process,
     declarative::DeclarativeMacroExpander,
     fixup::{self, SyntaxFixupUndoInfo},
@@ -20,9 +19,9 @@ use crate::{
     proc_macro::ProcMacros,
     span_map::{RealSpanMap, SpanMap, SpanMapRef},
     tt, AstId, BuiltinAttrExpander, BuiltinDeriveExpander, BuiltinFnLikeExpander,
-    CustomProcMacroExpander, EagerCallInfo, ExpandError, ExpandResult, ExpandTo, ExpansionSpanMap,
+    CustomProcMacroExpander, EagerCallInfo, EagerExpander, ExpandError, ExpandResult, ExpandTo,
-    HirFileId, HirFileIdRepr, Lookup, MacroCallId, MacroCallKind, MacroCallLoc, MacroDefId,
+    ExpansionSpanMap, HirFileId, HirFileIdRepr, Lookup, MacroCallId, MacroCallKind, MacroCallLoc,
-    MacroDefKind, MacroFileId,
+    MacroDefId, MacroDefKind, MacroFileId,
 };
 /// This is just to ensure the types of smart_macro_arg and macro_arg are the same
 type MacroArgResult = (Arc<tt::Subtree>, SyntaxFixupUndoInfo, Span);

crates/hir-expand/src/lib.rs

@@ -6,9 +6,7 @@
 #![cfg_attr(feature = "in-rust-tree", feature(rustc_private))]
 
 pub mod attrs;
-pub mod builtin_attr_macro;
+pub mod builtin;
-pub mod builtin_derive_macro;
-pub mod builtin_fn_macro;
 pub mod change;
 pub mod db;
 pub mod declarative;
@@ -19,7 +17,6 @@ pub mod inert_attr_macro;
 pub mod mod_path;
 pub mod name;
 pub mod proc_macro;
-pub mod quote;
 pub mod span_map;
 
 mod cfg_process;
@@ -29,7 +26,7 @@ use attrs::collect_attrs;
 use rustc_hash::FxHashMap;
 use triomphe::Arc;
 
-use std::{fmt, hash::Hash};
+use std::hash::Hash;
 
 use base_db::{salsa::InternValueTrivial, CrateId};
 use either::Either;
@@ -44,9 +41,10 @@ use syntax::{
 
 use crate::{
     attrs::AttrId,
-    builtin_attr_macro::BuiltinAttrExpander,
+    builtin::{
-    builtin_derive_macro::BuiltinDeriveExpander,
+        include_input_to_file_id, BuiltinAttrExpander, BuiltinDeriveExpander,
-    builtin_fn_macro::{BuiltinFnLikeExpander, EagerExpander},
+        BuiltinFnLikeExpander, EagerExpander,
+    },
     db::ExpandDatabase,
     mod_path::ModPath,
     proc_macro::{CustomProcMacroExpander, ProcMacroKind},
@@ -127,7 +125,8 @@ pub type ExpandResult<T> = ValueResult<T, ExpandError>;
 
 #[derive(Debug, PartialEq, Eq, Clone, Hash)]
 pub enum ExpandError {
-    UnresolvedProcMacro(CrateId),
+    ProcMacroAttrExpansionDisabled,
+    MissingProcMacroExpander(CrateId),
     /// The macro expansion is disabled.
     MacroDisabled,
     MacroDefinition,
@@ -141,6 +140,26 @@ impl ExpandError {
     pub fn other(msg: impl Into<Box<str>>) -> Self {
         ExpandError::Other(Arc::new(msg.into()))
     }
+
+    pub fn render_to_string(&self, db: &dyn ExpandDatabase) -> (String, bool) {
+        match self {
+            Self::ProcMacroAttrExpansionDisabled => {
+                ("procedural attribute macro expansion is disabled".to_owned(), false)
+            }
+            Self::MacroDisabled => ("proc-macro is explicitly disabled".to_owned(), false),
+            &Self::MissingProcMacroExpander(def_crate) => {
+                match db.proc_macros().get_error_for_crate(def_crate) {
+                    Some((e, hard_err)) => (e.to_owned(), hard_err),
+                    None => ("missing expander".to_owned(), true),
+                }
+            }
+            Self::MacroDefinition => ("macro definition has parse errors".to_owned(), true),
+            Self::Mbe(e) => (e.to_string(), true),
+            Self::RecursionOverflow => ("overflow expanding the original macro".to_owned(), true),
+            Self::Other(e) => ((***e).to_owned(), true),
+            Self::ProcMacroPanic(e) => ((***e).to_owned(), true),
+        }
+    }
 }
 
 impl From<mbe::ExpandError> for ExpandError {
@@ -148,24 +167,6 @@ impl From<mbe::ExpandError> for ExpandError {
         Self::Mbe(mbe)
     }
 }
-
-impl fmt::Display for ExpandError {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            ExpandError::UnresolvedProcMacro(_) => f.write_str("unresolved proc-macro"),
-            ExpandError::Mbe(it) => it.fmt(f),
-            ExpandError::RecursionOverflow => f.write_str("overflow expanding the original macro"),
-            ExpandError::ProcMacroPanic(it) => {
-                f.write_str("proc-macro panicked: ")?;
-                f.write_str(it)
-            }
-            ExpandError::Other(it) => f.write_str(it),
-            ExpandError::MacroDisabled => f.write_str("macro disabled"),
-            ExpandError::MacroDefinition => f.write_str("macro definition has parse errors"),
-        }
-    }
-}
-
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct MacroCallLoc {
     pub def: MacroDefId,
@@ -277,11 +278,9 @@ impl HirFileIdExt for HirFileId {
                     let loc = db.lookup_intern_macro_call(file.macro_call_id);
                     if loc.def.is_include() {
                         if let MacroCallKind::FnLike { eager: Some(eager), .. } = &loc.kind {
-                            if let Ok(it) = builtin_fn_macro::include_input_to_file_id(
+                            if let Ok(it) =
-                                db,
+                                include_input_to_file_id(db, file.macro_call_id, &eager.arg)
-                                file.macro_call_id,
+                            {
-                                &eager.arg,
-                            ) {
                                 break it;
                             }
                         }
@@ -572,9 +571,7 @@ impl MacroCallLoc {
     ) -> Option<EditionedFileId> {
         if self.def.is_include() {
             if let MacroCallKind::FnLike { eager: Some(eager), .. } = &self.kind {
-                if let Ok(it) =
+                if let Ok(it) = include_input_to_file_id(db, macro_call_id, &eager.arg) {
-                    builtin_fn_macro::include_input_to_file_id(db, macro_call_id, &eager.arg)
-                {
                     return Some(it);
                 }
             }

crates/hir-expand/src/proc_macro.rs

@@ -7,20 +7,10 @@ use base_db::{CrateId, Env};
 use intern::Symbol;
 use rustc_hash::FxHashMap;
 use span::Span;
-use stdx::never;
 use triomphe::Arc;
 
 use crate::{db::ExpandDatabase, tt, ExpandError, ExpandResult};
 
-#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
-pub struct ProcMacroId(u32);
-
-impl ProcMacroId {
-    pub fn new(u32: u32) -> Self {
-        ProcMacroId(u32)
-    }
-}
-
 #[derive(Copy, Clone, Eq, PartialEq, Debug, Hash)]
 pub enum ProcMacroKind {
     CustomDerive,
@@ -28,7 +18,10 @@ pub enum ProcMacroKind {
     Attr,
 }
 
+/// A proc-macro expander implementation.
 pub trait ProcMacroExpander: fmt::Debug + Send + Sync + RefUnwindSafe {
+    /// Run the expander with the given input subtree, optional attribute input subtree (for
+    /// [`ProcMacroKind::Attr`]), environment variables, and span information.
     fn expand(
         &self,
         subtree: &tt::Subtree,
@@ -42,57 +35,162 @@ pub trait ProcMacroExpander: fmt::Debug + Send + Sync + RefUnwindSafe {
 
 #[derive(Debug)]
 pub enum ProcMacroExpansionError {
+    /// The proc-macro panicked.
     Panic(String),
-    /// Things like "proc macro server was killed by OOM".
+    /// The server itself errored out.
     System(String),
 }
 
-pub type ProcMacroLoadResult = Result<Vec<ProcMacro>, String>;
+pub type ProcMacroLoadResult = Result<Vec<ProcMacro>, (String, bool)>;
+type StoredProcMacroLoadResult = Result<Box<[ProcMacro]>, (Box<str>, bool)>;
 
-pub type ProcMacros = FxHashMap<CrateId, ProcMacroLoadResult>;
+#[derive(Default, Debug)]
+pub struct ProcMacrosBuilder(FxHashMap<CrateId, StoredProcMacroLoadResult>);
+impl ProcMacrosBuilder {
+    pub fn insert(&mut self, proc_macros_crate: CrateId, proc_macro: ProcMacroLoadResult) {
+        self.0.insert(
+            proc_macros_crate,
+            match proc_macro {
+                Ok(it) => Ok(it.into_boxed_slice()),
+                Err((e, hard_err)) => Err((e.into_boxed_str(), hard_err)),
+            },
+        );
+    }
+    pub fn build(mut self) -> ProcMacros {
+        self.0.shrink_to_fit();
+        ProcMacros(self.0)
+    }
+}
 
+#[derive(Default, Debug)]
+pub struct ProcMacros(FxHashMap<CrateId, StoredProcMacroLoadResult>);
+
+impl FromIterator<(CrateId, ProcMacroLoadResult)> for ProcMacros {
+    fn from_iter<T: IntoIterator<Item = (CrateId, ProcMacroLoadResult)>>(iter: T) -> Self {
+        let mut builder = ProcMacrosBuilder::default();
+        for (k, v) in iter {
+            builder.insert(k, v);
+        }
+        builder.build()
+    }
+}
+
+impl ProcMacros {
+    fn get(&self, krate: CrateId, idx: u32) -> Result<&ProcMacro, ExpandError> {
+        let proc_macros = match self.0.get(&krate) {
+            Some(Ok(proc_macros)) => proc_macros,
+            Some(Err(_)) | None => {
+                return Err(ExpandError::other("internal error: no proc macros for crate"));
+            }
+        };
+        proc_macros.get(idx as usize).ok_or_else(|| {
+                ExpandError::other(
+                    format!(
+                        "internal error: proc-macro index out of bounds: the length is {} but the index is {}",
+                        proc_macros.len(),
+                        idx
+                    )
+                )
+            }
+        )
+    }
+
+    pub fn get_error_for_crate(&self, krate: CrateId) -> Option<(&str, bool)> {
+        self.0.get(&krate).and_then(|it| it.as_ref().err()).map(|(e, hard_err)| (&**e, *hard_err))
+    }
+
+    /// Fetch the [`CustomProcMacroExpander`]s and their corresponding names for the given crate.
+    pub fn for_crate(
+        &self,
+        krate: CrateId,
+        def_site_ctx: span::SyntaxContextId,
+    ) -> Option<Box<[(crate::name::Name, CustomProcMacroExpander, bool)]>> {
+        match self.0.get(&krate) {
+            Some(Ok(proc_macros)) => Some({
+                proc_macros
+                    .iter()
+                    .enumerate()
+                    .map(|(idx, it)| {
+                        let name = crate::name::Name::new_symbol(it.name.clone(), def_site_ctx);
+                        (name, CustomProcMacroExpander::new(idx as u32), it.disabled)
+                    })
+                    .collect()
+            }),
+            _ => None,
+        }
+    }
+}
+
+/// A loaded proc-macro.
 #[derive(Debug, Clone)]
 pub struct ProcMacro {
+    /// The name of the proc macro.
     pub name: Symbol,
     pub kind: ProcMacroKind,
+    /// The expander handle for this proc macro.
     pub expander: sync::Arc<dyn ProcMacroExpander>,
+    /// Whether this proc-macro is disabled for early name resolution. Notably, the
+    /// [`Self::expander`] is still usable.
     pub disabled: bool,
 }
 
+/// A custom proc-macro expander handle. This handle together with its crate resolves to a [`ProcMacro`]
 #[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)]
 pub struct CustomProcMacroExpander {
-    proc_macro_id: ProcMacroId,
+    proc_macro_id: u32,
 }
 
 impl CustomProcMacroExpander {
-    const DUMMY_ID: u32 = !0;
+    const MISSING_EXPANDER: u32 = !0;
     const DISABLED_ID: u32 = !1;
+    const PROC_MACRO_ATTR_DISABLED: u32 = !2;
 
-    pub fn new(proc_macro_id: ProcMacroId) -> Self {
+    pub fn new(proc_macro_id: u32) -> Self {
-        assert_ne!(proc_macro_id.0, Self::DUMMY_ID);
+        assert_ne!(proc_macro_id, Self::MISSING_EXPANDER);
-        assert_ne!(proc_macro_id.0, Self::DISABLED_ID);
+        assert_ne!(proc_macro_id, Self::DISABLED_ID);
+        assert_ne!(proc_macro_id, Self::PROC_MACRO_ATTR_DISABLED);
         Self { proc_macro_id }
     }
 
-    /// A dummy expander that always errors. This is used for proc-macros that are missing, usually
+    /// An expander that always errors due to the actual proc-macro expander missing.
-    /// due to them not being built yet.
+    pub const fn missing_expander() -> Self {
-    pub const fn dummy() -> Self {
+        Self { proc_macro_id: Self::MISSING_EXPANDER }
-        Self { proc_macro_id: ProcMacroId(Self::DUMMY_ID) }
-    }
-
-    /// The macro was not yet resolved.
-    pub const fn is_dummy(&self) -> bool {
-        self.proc_macro_id.0 == Self::DUMMY_ID
     }
 
     /// A dummy expander that always errors. This expander is used for macros that have been disabled.
     pub const fn disabled() -> Self {
-        Self { proc_macro_id: ProcMacroId(Self::DISABLED_ID) }
+        Self { proc_macro_id: Self::DISABLED_ID }
+    }
+
+    /// A dummy expander that always errors. This expander is used for attribute macros when
+    /// proc-macro attribute expansion is disabled.
+    pub const fn disabled_proc_attr() -> Self {
+        Self { proc_macro_id: Self::PROC_MACRO_ATTR_DISABLED }
+    }
+
+    /// The macro-expander is missing or has yet to be build.
+    pub const fn is_missing(&self) -> bool {
+        self.proc_macro_id == Self::MISSING_EXPANDER
     }
 
     /// The macro is explicitly disabled and cannot be expanded.
     pub const fn is_disabled(&self) -> bool {
-        self.proc_macro_id.0 == Self::DISABLED_ID
+        self.proc_macro_id == Self::DISABLED_ID
+    }
+
+    /// The macro is explicitly disabled due to proc-macro attribute expansion being disabled.
+    pub const fn is_disabled_proc_attr(&self) -> bool {
+        self.proc_macro_id == Self::PROC_MACRO_ATTR_DISABLED
+    }
+
+    /// The macro is explicitly disabled due to proc-macro attribute expansion being disabled.
+    pub const fn as_expand_error(&self, def_crate: CrateId) -> Option<ExpandError> {
+        match self.proc_macro_id {
+            Self::PROC_MACRO_ATTR_DISABLED => Some(ExpandError::ProcMacroAttrExpansionDisabled),
+            Self::DISABLED_ID => Some(ExpandError::MacroDisabled),
+            Self::MISSING_EXPANDER => Some(ExpandError::MissingProcMacroExpander(def_crate)),
+            _ => None,
+        }
     }
 
     pub fn expand(
@@ -107,38 +205,27 @@ impl CustomProcMacroExpander {
         mixed_site: Span,
     ) -> ExpandResult<tt::Subtree> {
         match self.proc_macro_id {
-            ProcMacroId(Self::DUMMY_ID) => ExpandResult::new(
+            Self::PROC_MACRO_ATTR_DISABLED => ExpandResult::new(
                 tt::Subtree::empty(tt::DelimSpan { open: call_site, close: call_site }),
-                ExpandError::UnresolvedProcMacro(def_crate),
+                ExpandError::ProcMacroAttrExpansionDisabled,
             ),
-            ProcMacroId(Self::DISABLED_ID) => ExpandResult::new(
+            Self::MISSING_EXPANDER => ExpandResult::new(
+                tt::Subtree::empty(tt::DelimSpan { open: call_site, close: call_site }),
+                ExpandError::MissingProcMacroExpander(def_crate),
+            ),
+            Self::DISABLED_ID => ExpandResult::new(
                 tt::Subtree::empty(tt::DelimSpan { open: call_site, close: call_site }),
                 ExpandError::MacroDisabled,
             ),
-            ProcMacroId(id) => {
+            id => {
                 let proc_macros = db.proc_macros();
-                let proc_macros = match proc_macros.get(&def_crate) {
+                let proc_macro = match proc_macros.get(def_crate, id) {
-                    Some(Ok(proc_macros)) => proc_macros,
+                    Ok(proc_macro) => proc_macro,
-                    Some(Err(_)) | None => {
+                    Err(e) => {
-                        never!("Non-dummy expander even though there are no proc macros");
                         return ExpandResult::new(
                             tt::Subtree::empty(tt::DelimSpan { open: call_site, close: call_site }),
-                            ExpandError::other("Internal error"),
+                            e,
-                        );
+                        )
-                    }
-                };
-                let proc_macro = match proc_macros.get(id as usize) {
-                    Some(proc_macro) => proc_macro,
-                    None => {
-                        never!(
-                            "Proc macro index out of bounds: the length is {} but the index is {}",
-                            proc_macros.len(),
-                            id
-                        );
-                        return ExpandResult::new(
-                            tt::Subtree::empty(tt::DelimSpan { open: call_site, close: call_site }),
-                            ExpandError::other("Internal error: proc-macro index out of bounds"),
-                        );
                     }
                 };
 

crates/hir/src/diagnostics.rs

@@ -6,7 +6,6 @@
 pub use hir_ty::diagnostics::{CaseType, IncorrectCase};
 use hir_ty::{db::HirDatabase, diagnostics::BodyValidationDiagnostic, InferenceDiagnostic};
 
-use base_db::CrateId;
 use cfg::{CfgExpr, CfgOptions};
 use either::Either;
 pub use hir_def::VariantId;
@@ -15,7 +14,7 @@ use hir_expand::{name::Name, HirFileId, InFile};
 use syntax::{ast, AstPtr, SyntaxError, SyntaxNodePtr, TextRange};
 use triomphe::Arc;
 
-use crate::{AssocItem, Field, Local, MacroKind, Trait, Type};
+use crate::{AssocItem, Field, Local, Trait, Type};
 
 macro_rules! diagnostics {
     ($($diag:ident,)*) => {
@@ -90,7 +89,6 @@ diagnostics![
     UnresolvedMethodCall,
     UnresolvedModule,
     UnresolvedIdent,
-    UnresolvedProcMacro,
     UnusedMut,
     UnusedVariable,
 ];
@@ -150,23 +148,12 @@ pub struct InactiveCode {
     pub opts: CfgOptions,
 }
 
-#[derive(Debug, Clone, Eq, PartialEq)]
-pub struct UnresolvedProcMacro {
-    pub node: InFile<SyntaxNodePtr>,
-    /// If the diagnostic can be pinpointed more accurately than via `node`, this is the `TextRange`
-    /// to use instead.
-    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: CrateId,
-}
-
 #[derive(Debug, Clone, Eq, PartialEq)]
 pub struct MacroError {
     pub node: InFile<SyntaxNodePtr>,
     pub precise_location: Option<TextRange>,
     pub message: String,
+    pub error: bool,
 }
 
 #[derive(Debug, Clone, Eq, PartialEq)]

crates/hir/src/lib.rs

@@ -137,7 +137,7 @@ pub use {
         hygiene::{marks_rev, SyntaxContextExt},
         inert_attr_macro::AttributeTemplate,
         name::Name,
-        proc_macro::ProcMacros,
+        proc_macro::{ProcMacros, ProcMacrosBuilder},
         tt, ExpandResult, HirFileId, HirFileIdExt, MacroFileId, MacroFileIdExt,
     },
     hir_ty::{
@@ -833,14 +833,10 @@ fn macro_call_diagnostics(
     let ValueResult { value: parse_errors, err } = &*e;
     if let Some(err) = err {
         let loc = db.lookup_intern_macro_call(macro_call_id);
-        let (node, precise_location, macro_name, kind) = precise_macro_call_location(&loc.kind, db);
+        let (node, precise_location, _macro_name, _kind) =
-        let diag = match err {
+            precise_macro_call_location(&loc.kind, db);
-            &hir_expand::ExpandError::UnresolvedProcMacro(krate) => {
+        let (message, error) = err.render_to_string(db.upcast());
-                UnresolvedProcMacro { node, precise_location, macro_name, kind, krate }.into()
+        acc.push(MacroError { node, precise_location, message, error }.into());
-            }
-            err => MacroError { node, precise_location, message: err.to_string() }.into(),
-        };
-        acc.push(diag);
     }
 
     if !parse_errors.is_empty() {
@@ -895,6 +891,19 @@ fn emit_def_diagnostic_(
             acc.push(UnresolvedExternCrate { decl: InFile::new(ast.file_id, item) }.into());
         }
 
+        DefDiagnosticKind::MacroError { ast, err } => {
+            let item = ast.to_ptr(db.upcast());
+            let (message, error) = err.render_to_string(db.upcast());
+            acc.push(
+                MacroError {
+                    node: InFile::new(ast.file_id, item.syntax_node_ptr()),
+                    precise_location: None,
+                    message,
+                    error,
+                }
+                .into(),
+            )
+        }
         DefDiagnosticKind::UnresolvedImport { id, index } => {
             let file_id = id.file_id();
             let item_tree = id.item_tree(db.upcast());
@@ -991,13 +1000,6 @@ fn emit_def_diagnostic_(
                 Some(())
             })();
         }
-        DefDiagnosticKind::UnresolvedProcMacro { ast, krate } => {
-            let (node, precise_location, macro_name, kind) = precise_macro_call_location(ast, db);
-            acc.push(
-                UnresolvedProcMacro { node, precise_location, macro_name, kind, krate: *krate }
-                    .into(),
-            );
-        }
         DefDiagnosticKind::UnresolvedMacroCall { ast, path } => {
             let (node, precise_location, _, _) = precise_macro_call_location(ast, db);
             acc.push(
@@ -1795,20 +1797,17 @@ impl DefWithBody {
                 BodyDiagnostic::InactiveCode { node, cfg, opts } => {
                     InactiveCode { node: *node, cfg: cfg.clone(), opts: opts.clone() }.into()
                 }
-                BodyDiagnostic::MacroError { node, message } => MacroError {
+                BodyDiagnostic::MacroError { node, err } => {
+                    let (message, error) = err.render_to_string(db.upcast());
+
+                    MacroError {
                         node: (*node).map(|it| it.into()),
                         precise_location: None,
-                    message: message.to_string(),
+                        message,
+                        error,
                     }
-                .into(),
+                    .into()
-                BodyDiagnostic::UnresolvedProcMacro { node, krate } => UnresolvedProcMacro {
-                    node: (*node).map(|it| it.into()),
-                    precise_location: None,
-                    macro_name: None,
-                    kind: MacroKind::ProcMacro,
-                    krate: *krate,
                 }
-                .into(),
                 BodyDiagnostic::UnresolvedMacroCall { node, path } => UnresolvedMacroCall {
                     macro_call: (*node).map(|ast_ptr| ast_ptr.into()),
                     precise_location: None,

crates/hir/src/semantics.rs

@@ -19,7 +19,7 @@ use hir_def::{
 };
 use hir_expand::{
     attrs::collect_attrs,
-    builtin_fn_macro::{BuiltinFnLikeExpander, EagerExpander},
+    builtin::{BuiltinFnLikeExpander, EagerExpander},
     db::ExpandDatabase,
     files::InRealFile,
     name::AsName,

crates/ide-diagnostics/src/handlers/macro_error.rs

@@ -7,7 +7,10 @@ pub(crate) fn macro_error(ctx: &DiagnosticsContext<'_>, d: &hir::MacroError) ->
     // Use more accurate position if available.
     let display_range = ctx.resolve_precise_location(&d.node, d.precise_location);
     Diagnostic::new(
-        DiagnosticCode::Ra("macro-error", Severity::Error),
+        DiagnosticCode::Ra(
+            "macro-error",
+            if d.error { Severity::Error } else { Severity::WeakWarning },
+        ),
         d.message.clone(),
         display_range,
     )

crates/ide-diagnostics/src/handlers/unresolved_proc_macro.rs

@@ -1,45 +0,0 @@
-use hir::db::DefDatabase;
-
-use crate::{Diagnostic, DiagnosticCode, DiagnosticsContext, Severity};
-
-// Diagnostic: unresolved-proc-macro
-//
-// This diagnostic is shown when a procedural macro can not be found. This usually means that
-// procedural macro support is simply disabled (and hence is only a weak hint instead of an error),
-// but can also indicate project setup problems.
-//
-// If you are seeing a lot of "proc macro not expanded" warnings, you can add this option to the
-// `rust-analyzer.diagnostics.disabled` list to prevent them from showing. Alternatively you can
-// enable support for procedural macros (see `rust-analyzer.procMacro.attributes.enable`).
-pub(crate) fn unresolved_proc_macro(
-    ctx: &DiagnosticsContext<'_>,
-    d: &hir::UnresolvedProcMacro,
-    proc_macros_enabled: bool,
-    proc_attr_macros_enabled: bool,
-) -> Diagnostic {
-    // Use more accurate position if available.
-    let display_range = ctx.resolve_precise_location(&d.node, d.precise_location);
-
-    let config_enabled = match d.kind {
-        hir::MacroKind::Attr => proc_macros_enabled && proc_attr_macros_enabled,
-        _ => proc_macros_enabled,
-    };
-
-    let not_expanded_message = match &d.macro_name {
-        Some(name) => format!("proc macro `{name}` not expanded"),
-        None => "proc macro not expanded".to_owned(),
-    };
-    let severity = if config_enabled { Severity::Error } else { Severity::WeakWarning };
-    let def_map = ctx.sema.db.crate_def_map(d.krate);
-    let message = if config_enabled {
-        def_map.proc_macro_loading_error().unwrap_or("internal error")
-    } else {
-        match d.kind {
-            hir::MacroKind::Attr if proc_macros_enabled => "attribute macro expansion is disabled",
-            _ => "proc-macro expansion is disabled",
-        }
-    };
-    let message = format!("{not_expanded_message}: {message}");
-
-    Diagnostic::new(DiagnosticCode::Ra("unresolved-proc-macro", severity), message, display_range)
-}

crates/ide-diagnostics/src/lib.rs

@@ -62,7 +62,6 @@ mod handlers {
     pub(crate) mod unresolved_macro_call;
     pub(crate) mod unresolved_method;
     pub(crate) mod unresolved_module;
-    pub(crate) mod unresolved_proc_macro;
     pub(crate) mod unused_variables;
 
     // The handlers below are unusual, the implement the diagnostics as well.
@@ -405,7 +404,6 @@ pub fn diagnostics(
             AnyDiagnostic::UnresolvedMacroCall(d) => handlers::unresolved_macro_call::unresolved_macro_call(&ctx, &d),
             AnyDiagnostic::UnresolvedMethodCall(d) => handlers::unresolved_method::unresolved_method(&ctx, &d),
             AnyDiagnostic::UnresolvedModule(d) => handlers::unresolved_module::unresolved_module(&ctx, &d),
-            AnyDiagnostic::UnresolvedProcMacro(d) => handlers::unresolved_proc_macro::unresolved_proc_macro(&ctx, &d, config.proc_macros_enabled, config.proc_attr_macros_enabled),
             AnyDiagnostic::UnusedMut(d) => match handlers::mutability_errors::unused_mut(&ctx, &d) {
                 Some(it) => it,
                 None => continue,

crates/ide/src/lib.rs

@@ -43,7 +43,6 @@ mod parent_module;
 mod references;
 mod rename;
 mod runnables;
-mod shuffle_crate_graph;
 mod signature_help;
 mod ssr;
 mod static_index;
@@ -202,10 +201,6 @@ impl AnalysisHost {
     pub fn raw_database_mut(&mut self) -> &mut RootDatabase {
         &mut self.db
     }
-
-    pub fn shuffle_crate_graph(&mut self) {
-        shuffle_crate_graph::shuffle_crate_graph(&mut self.db);
-    }
 }
 
 impl Default for AnalysisHost {

crates/ide/src/shuffle_crate_graph.rs

@@ -1,58 +0,0 @@
-use hir::{db::ExpandDatabase, ProcMacros};
-use ide_db::{
-    base_db::{salsa::Durability, CrateGraph, SourceDatabase},
-    FxHashMap, RootDatabase,
-};
-use triomphe::Arc;
-
-// Feature: Shuffle Crate Graph
-//
-// Randomizes all crate IDs in the crate graph, for debugging.
-//
-// |===
-// | Editor  | Action Name
-//
-// | VS Code | **rust-analyzer: Shuffle Crate Graph**
-// |===
-pub(crate) fn shuffle_crate_graph(db: &mut RootDatabase) {
-    let crate_graph = db.crate_graph();
-    let proc_macros = db.proc_macros();
-
-    let mut shuffled_ids = crate_graph.iter().collect::<Vec<_>>();
-
-    let mut rng = oorandom::Rand32::new(stdx::rand::seed());
-    stdx::rand::shuffle(&mut shuffled_ids, |i| rng.rand_range(0..i as u32) as usize);
-
-    let mut new_graph = CrateGraph::default();
-    let mut new_proc_macros = ProcMacros::default();
-
-    let mut map = FxHashMap::default();
-    for old_id in shuffled_ids.iter().copied() {
-        let data = &crate_graph[old_id];
-        let new_id = new_graph.add_crate_root(
-            data.root_file_id,
-            data.edition,
-            data.display_name.clone(),
-            data.version.clone(),
-            data.cfg_options.clone(),
-            data.potential_cfg_options.clone(),
-            data.env.clone(),
-            data.is_proc_macro,
-            data.origin.clone(),
-        );
-        new_proc_macros.insert(new_id, proc_macros[&old_id].clone());
-        map.insert(old_id, new_id);
-    }
-
-    for old_id in shuffled_ids.iter().copied() {
-        let data = &crate_graph[old_id];
-        for dep in &data.dependencies {
-            let mut new_dep = dep.clone();
-            new_dep.crate_id = map[&dep.crate_id];
-            new_graph.add_dep(map[&old_id], new_dep).unwrap();
-        }
-    }
-
-    db.set_crate_graph_with_durability(Arc::new(new_graph), Durability::HIGH);
-    db.set_proc_macros_with_durability(Arc::new(new_proc_macros), Durability::HIGH);
-}

crates/load-cargo/src/lib.rs

@@ -68,11 +68,14 @@ pub fn load_workspace(
     let proc_macro_server = match &load_config.with_proc_macro_server {
         ProcMacroServerChoice::Sysroot => ws
             .find_sysroot_proc_macro_srv()
-            .and_then(|it| ProcMacroServer::spawn(&it, extra_env).map_err(Into::into)),
+            .and_then(|it| ProcMacroServer::spawn(&it, extra_env).map_err(Into::into))
+            .map_err(|e| (e, true)),
         ProcMacroServerChoice::Explicit(path) => {
-            ProcMacroServer::spawn(path, extra_env).map_err(Into::into)
+            ProcMacroServer::spawn(path, extra_env).map_err(Into::into).map_err(|e| (e, true))
+        }
+        ProcMacroServerChoice::None => {
+            Err((anyhow::format_err!("proc macro server disabled"), false))
         }
-        ProcMacroServerChoice::None => Err(anyhow::format_err!("proc macro server disabled")),
     };
 
     let (crate_graph, proc_macros) = ws.to_crate_graph(
@@ -87,7 +90,7 @@ pub fn load_workspace(
     let proc_macros = {
         let proc_macro_server = match &proc_macro_server {
             Ok(it) => Ok(it),
-            Err(e) => Err(e.to_string()),
+            Err((e, hard_err)) => Err((e.to_string(), *hard_err)),
         };
         proc_macros
             .into_iter()
@@ -95,7 +98,7 @@ pub fn load_workspace(
                 (
                     crate_id,
                     path.map_or_else(
-                        |_| Err("proc macro crate is missing dylib".to_owned()),
+                        |e| Err((e, true)),
                         |(_, path)| {
                             proc_macro_server.as_ref().map_err(Clone::clone).and_then(
                                 |proc_macro_server| load_proc_macro(proc_macro_server, &path, &[]),
@@ -355,8 +358,7 @@ impl SourceRootConfig {
     }
 }
 
-/// Load the proc-macros for the given lib path, replacing all expanders whose names are in `dummy_replace`
+/// Load the proc-macros for the given lib path, disabling all expanders whose names are in `ignored_macros`.
-/// with an identity dummy expander.
 pub fn load_proc_macro(
     server: &ProcMacroServer,
     path: &AbsPath,
@@ -383,7 +385,7 @@ pub fn load_proc_macro(
         }
         Err(e) => {
             tracing::warn!("proc-macro loading for {path} failed: {e}");
-            Err(e)
+            Err((e, true))
         }
     }
 }

crates/project-model/src/workspace.rs

@@ -934,7 +934,10 @@ fn project_json_to_crate_graph(
                 if *is_proc_macro {
                     if let Some(path) = proc_macro_dylib_path.clone() {
                         let node = Ok((
-                            display_name.as_ref().map(|it| it.canonical_name().as_str().to_owned()),
+                            display_name
+                                .as_ref()
+                                .map(|it| it.canonical_name().as_str().to_owned())
+                                .unwrap_or_else(|| format!("crate{}", idx.0)),
                             path,
                         ));
                         proc_macros.insert(crate_graph_crate_id, node);
@@ -1355,8 +1358,8 @@ fn add_target_crate_root(
     );
     if let TargetKind::Lib { is_proc_macro: true } = kind {
         let proc_macro = match build_data.as_ref().map(|it| it.proc_macro_dylib_path.as_ref()) {
-            Some(it) => it.cloned().map(|path| Ok((Some(cargo_name.to_owned()), path))),
+            Some(it) => it.cloned().map(|path| Ok((cargo_name.to_owned(), path))),
-            None => Some(Err("crate has not yet been built".to_owned())),
+            None => Some(Err("proc-macro crate is missing its build data".to_owned())),
         };
         if let Some(proc_macro) = proc_macro {
             proc_macros.insert(crate_id, proc_macro);

crates/rust-analyzer/src/handlers/request.rs

@@ -134,11 +134,6 @@ pub(crate) fn handle_memory_usage(state: &mut GlobalState, _: ()) -> anyhow::Res
     Ok(out)
 }
 
-pub(crate) fn handle_shuffle_crate_graph(state: &mut GlobalState, _: ()) -> anyhow::Result<()> {
-    state.analysis_host.shuffle_crate_graph();
-    Ok(())
-}
-
 pub(crate) fn handle_syntax_tree(
     snap: GlobalStateSnapshot,
     params: lsp_ext::SyntaxTreeParams,

crates/rust-analyzer/src/lsp/ext.rs

@@ -75,14 +75,6 @@ impl Request for MemoryUsage {
     const METHOD: &'static str = "rust-analyzer/memoryUsage";
 }
 
-pub enum ShuffleCrateGraph {}
-
-impl Request for ShuffleCrateGraph {
-    type Params = ();
-    type Result = ();
-    const METHOD: &'static str = "rust-analyzer/shuffleCrateGraph";
-}
-
 pub enum ReloadWorkspace {}
 
 impl Request for ReloadWorkspace {

crates/rust-analyzer/src/main_loop.rs

@@ -1018,7 +1018,6 @@ impl GlobalState {
             .on_sync_mut::<lsp_ext::ReloadWorkspace>(handlers::handle_workspace_reload)
             .on_sync_mut::<lsp_ext::RebuildProcMacros>(handlers::handle_proc_macros_rebuild)
             .on_sync_mut::<lsp_ext::MemoryUsage>(handlers::handle_memory_usage)
-            .on_sync_mut::<lsp_ext::ShuffleCrateGraph>(handlers::handle_shuffle_crate_graph)
             .on_sync_mut::<lsp_ext::RunTest>(handlers::handle_run_test)
             // Request handlers which are related to the user typing
             // are run on the main thread to reduce latency:

crates/rust-analyzer/src/reload.rs

@@ -16,8 +16,7 @@
 use std::{iter, mem};
 
 use flycheck::{FlycheckConfig, FlycheckHandle};
-use hir::{db::DefDatabase, ChangeWithProcMacros, ProcMacros};
+use hir::{db::DefDatabase, ChangeWithProcMacros, ProcMacros, ProcMacrosBuilder};
-use ide::CrateId;
 use ide_db::{
     base_db::{salsa::Durability, CrateGraph, ProcMacroPaths, Version},
     FxHashMap,
@@ -371,43 +370,44 @@ impl GlobalState {
                 }
             };
 
-            let mut res = FxHashMap::default();
+            let mut builder = ProcMacrosBuilder::default();
             let chain = proc_macro_clients
                 .iter()
                 .map(|res| res.as_ref().map_err(|e| e.to_string()))
-                .chain(iter::repeat_with(|| Err("Proc macros servers are not running".into())));
+                .chain(iter::repeat_with(|| Err("proc-macro-srv is not running".into())));
             for (client, paths) in chain.zip(paths) {
-                res.extend(paths.into_iter().map(move |(crate_id, res)| {
+                paths
+                    .into_iter()
+                    .map(move |(crate_id, res)| {
                         (
                             crate_id,
                             res.map_or_else(
-                            |_| Err("proc macro crate is missing dylib".to_owned()),
+                                |e| Err((e, true)),
                                 |(crate_name, path)| {
                                     progress(path.to_string());
-                                client.as_ref().map_err(Clone::clone).and_then(|client| {
+                                    client.as_ref().map_err(|it| (it.clone(), true)).and_then(
+                                        |client| {
                                             load_proc_macro(
                                                 client,
                                                 &path,
-                                        crate_name
+                                                ignored_proc_macros
-                                            .as_deref()
+                                                    .iter()
-                                            .and_then(|crate_name| {
+                                                    .find_map(|(name, macros)| {
-                                                ignored_proc_macros.iter().find_map(
+                                                        eq_ignore_underscore(name, &crate_name)
-                                                    |(name, macros)| {
-                                                        eq_ignore_underscore(name, crate_name)
                                                             .then_some(&**macros)
-                                                    },
-                                                )
                                                     })
                                                     .unwrap_or_default(),
                                             )
-                                })
+                                        },
+                                    )
                                 },
                             ),
                         )
-                }));
+                    })
+                    .for_each(|(krate, res)| builder.insert(krate, res));
             }
 
-            sender.send(Task::LoadProcMacros(ProcMacroProgress::End(res))).unwrap();
+            sender.send(Task::LoadProcMacros(ProcMacroProgress::End(builder.build()))).unwrap();
         });
     }
 
@@ -667,10 +667,17 @@ impl GlobalState {
             change.set_proc_macros(
                 crate_graph
                     .iter()
-                    .map(|id| (id, Err("Proc-macros have not been built yet".to_owned())))
+                    .map(|id| (id, Err(("proc-macro has not been built yet".to_owned(), true))))
                     .collect(),
             );
             self.fetch_proc_macros_queue.request_op(cause, proc_macro_paths);
+        } else {
+            change.set_proc_macros(
+                crate_graph
+                    .iter()
+                    .map(|id| (id, Err(("proc-macro expansion is disabled".to_owned(), false))))
+                    .collect(),
+            );
         }
         change.set_crate_graph(crate_graph);
         change.set_target_data_layouts(layouts);
@@ -809,12 +816,7 @@ pub fn ws_to_crate_graph(
     workspaces: &[ProjectWorkspace],
     extra_env: &FxHashMap<String, String>,
     mut load: impl FnMut(&AbsPath) -> Option<vfs::FileId>,
-) -> (
+) -> (CrateGraph, Vec<ProcMacroPaths>, Vec<Result<Arc<str>, Arc<str>>>, Vec<Option<Version>>) {
-    CrateGraph,
-    Vec<FxHashMap<CrateId, Result<(Option<String>, AbsPathBuf), String>>>,
-    Vec<Result<Arc<str>, Arc<str>>>,
-    Vec<Option<Version>>,
-) {
     let mut crate_graph = CrateGraph::default();
     let mut proc_macro_paths = Vec::default();
     let mut layouts = Vec::default();

crates/test-fixture/src/lib.rs

@@ -1,5 +1,5 @@
 //! A set of high-level utility fixture methods to use in tests.
-use std::{iter, mem, ops::Not, str::FromStr, sync};
+use std::{iter, mem, str::FromStr, sync};
 
 use base_db::{
     CrateDisplayName, CrateGraph, CrateId, CrateName, CrateOrigin, Dependency, Env, FileChange,
@@ -11,7 +11,7 @@ use hir_expand::{
     db::ExpandDatabase,
     files::FilePosition,
     proc_macro::{
-        ProcMacro, ProcMacroExpander, ProcMacroExpansionError, ProcMacroKind, ProcMacros,
+        ProcMacro, ProcMacroExpander, ProcMacroExpansionError, ProcMacroKind, ProcMacrosBuilder,
     },
     FileRange,
 };
@@ -303,7 +303,7 @@ impl ChangeFixture {
             }
         }
 
-        let mut proc_macros = ProcMacros::default();
+        let mut proc_macros = ProcMacrosBuilder::default();
         if !proc_macro_names.is_empty() {
             let proc_lib_file = file_id;
 
@@ -354,7 +354,7 @@ impl ChangeFixture {
 
         let mut change = ChangeWithProcMacros {
             source_change,
-            proc_macros: proc_macros.is_empty().not().then_some(proc_macros),
+            proc_macros: Some(proc_macros.build()),
             toolchains: Some(iter::repeat(toolchain).take(crate_graph.len()).collect()),
             target_data_layouts: Some(
                 iter::repeat(target_data_layout).take(crate_graph.len()).collect(),

docs/dev/lsp-extensions.md

@@ -1,5 +1,5 @@
 <!---
-lsp/ext.rs hash: f41950db4c7b3a5a
+lsp/ext.rs hash: e92e1f12229b0071
 
 If you need to change the above hash to make the test pass, please check if you
 need to adjust this doc as well and ping this issue:
@@ -789,14 +789,6 @@ Renders rust-analyzer's crate graph as an SVG image.
 
 If `full` is `true`, the graph includes non-workspace crates (crates.io dependencies as well as sysroot crates).
 
-## Shuffle Crate Graph
-
-**Method:** `rust-analyzer/shuffleCrateGraph`
-
-**Request:** `null`
-
-Shuffles the crate IDs in the crate graph, for debugging purposes.
-
 ## Expand Macro
 
 **Method:** `rust-analyzer/expandMacro`

editors/code/package.json

@@ -136,11 +136,6 @@
                 "title": "Debug ItemTree",
                 "category": "rust-analyzer (debug command)"
             },
-            {
-                "command": "rust-analyzer.shuffleCrateGraph",
-                "title": "Shuffle Crate Graph",
-                "category": "rust-analyzer (debug command)"
-            },
             {
                 "command": "rust-analyzer.memoryUsage",
                 "title": "Memory Usage (Clears Database)",

editors/code/src/commands.ts

@@ -100,12 +100,6 @@ export function memoryUsage(ctx: CtxInit): Cmd {
     };
 }
 
-export function shuffleCrateGraph(ctx: CtxInit): Cmd {
-    return async () => {
-        return ctx.client.sendRequest(ra.shuffleCrateGraph);
-    };
-}
-
 export function triggerParameterHints(_: CtxInit): Cmd {
     return async () => {
         const parameterHintsEnabled = vscode.workspace

editors/code/src/lsp_ext.ts

@@ -45,7 +45,6 @@ export const rebuildProcMacros = new lc.RequestType0<null, void>("rust-analyzer/
 export const runFlycheck = new lc.NotificationType<{
     textDocument: lc.TextDocumentIdentifier | null;
 }>("rust-analyzer/runFlycheck");
-export const shuffleCrateGraph = new lc.RequestType0<null, void>("rust-analyzer/shuffleCrateGraph");
 export const syntaxTree = new lc.RequestType<SyntaxTreeParams, string, void>(
     "rust-analyzer/syntaxTree",
 );

editors/code/src/main.ts

@@ -141,7 +141,6 @@ function createCommands(): Record<string, CommandFactory> {
 
         analyzerStatus: { enabled: commands.analyzerStatus },
         memoryUsage: { enabled: commands.memoryUsage },
-        shuffleCrateGraph: { enabled: commands.shuffleCrateGraph },
         reloadWorkspace: { enabled: commands.reloadWorkspace },
         rebuildProcMacros: { enabled: commands.rebuildProcMacros },
         matchingBrace: { enabled: commands.matchingBrace },