3 files changed, 109 insertions, 45 deletions

diff --git a/crates/hir_def/src/nameres/collector.rs b/crates/hir_def/src/nameres/collector.rs
index 2ae740d0e..3ea472908 100644
--- a/crates/hir_def/src/nameres/collector.rs
+++ b/crates/hir_def/src/nameres/collector.rs
@@ -33,7 +33,10 @@ use crate::{
     },
     macro_call_as_call_id,
     nameres::{
-        diagnostics::DefDiagnostic, mod_resolution::ModDir, path_resolution::ReachedFixedPoint,
+        diagnostics::DefDiagnostic,
+        mod_resolution::ModDir,
+        path_resolution::ReachedFixedPoint,
+        proc_macro::{ProcMacroDef, ProcMacroKind},
         BuiltinShadowMode, DefMap, ModuleData, ModuleOrigin, ResolveMode,
     },
     path::{ImportAlias, ModPath, PathKind},
@@ -44,8 +47,6 @@ use crate::{
     UnresolvedMacro,
 };
 
-use super::proc_macro::{ProcMacroDef, ProcMacroKind};
-
 const GLOB_RECURSION_LIMIT: usize = 100;
 const EXPANSION_DEPTH_LIMIT: usize = 128;
 const FIXED_POINT_LIMIT: usize = 8192;
diff --git a/crates/hir_def/src/nameres/diagnostics.rs b/crates/hir_def/src/nameres/diagnostics.rs
new file mode 100644
index 000000000..8f2f0ff9f
--- /dev/null
+++ b/crates/hir_def/src/nameres/diagnostics.rs
@@ -0,0 +1,90 @@
+//! Diagnostics emitted during DefMap construction.
+
+use cfg::{CfgExpr, CfgOptions};
+use hir_expand::MacroCallKind;
+use syntax::ast;
+
+use crate::{nameres::LocalModuleId, path::ModPath, AstId};
+
+#[derive(Debug, PartialEq, Eq)]
+pub enum DefDiagnosticKind {
+    UnresolvedModule { ast: AstId<ast::Module>, candidate: String },
+
+    UnresolvedExternCrate { ast: AstId<ast::ExternCrate> },
+
+    UnresolvedImport { ast: AstId<ast::Use>, index: usize },
+
+    UnconfiguredCode { ast: AstId<ast::Item>, cfg: CfgExpr, opts: CfgOptions },
+
+    UnresolvedProcMacro { ast: MacroCallKind },
+
+    UnresolvedMacroCall { ast: AstId<ast::MacroCall>, path: ModPath },
+
+    MacroError { ast: MacroCallKind, message: String },
+}
+
+#[derive(Debug, PartialEq, Eq)]
+pub struct DefDiagnostic {
+    pub in_module: LocalModuleId,
+    pub kind: DefDiagnosticKind,
+}
+
+impl DefDiagnostic {
+    pub(super) fn unresolved_module(
+        container: LocalModuleId,
+        declaration: AstId<ast::Module>,
+        candidate: String,
+    ) -> Self {
+        Self {
+            in_module: container,
+            kind: DefDiagnosticKind::UnresolvedModule { ast: declaration, candidate },
+        }
+    }
+
+    pub(super) fn unresolved_extern_crate(
+        container: LocalModuleId,
+        declaration: AstId<ast::ExternCrate>,
+    ) -> Self {
+        Self {
+            in_module: container,
+            kind: DefDiagnosticKind::UnresolvedExternCrate { ast: declaration },
+        }
+    }
+
+    pub(super) fn unresolved_import(
+        container: LocalModuleId,
+        ast: AstId<ast::Use>,
+        index: usize,
+    ) -> Self {
+        Self { in_module: container, kind: DefDiagnosticKind::UnresolvedImport { ast, index } }
+    }
+
+    pub(super) fn unconfigured_code(
+        container: LocalModuleId,
+        ast: AstId<ast::Item>,
+        cfg: CfgExpr,
+        opts: CfgOptions,
+    ) -> Self {
+        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 macro_error(
+        container: LocalModuleId,
+        ast: MacroCallKind,
+        message: String,
+    ) -> Self {
+        Self { in_module: container, kind: DefDiagnosticKind::MacroError { ast, message } }
+    }
+
+    pub(super) fn unresolved_macro_call(
+        container: LocalModuleId,
+        ast: AstId<ast::MacroCall>,
+        path: ModPath,
+    ) -> Self {
+        Self { in_module: container, kind: DefDiagnosticKind::UnresolvedMacroCall { ast, path } }
+    }
+}
diff --git a/crates/hir_def/src/nameres/tests/diagnostics.rs b/crates/hir_def/src/nameres/tests/diagnostics.rs
index 75147d973..ec6670952 100644
--- a/crates/hir_def/src/nameres/tests/diagnostics.rs
+++ b/crates/hir_def/src/nameres/tests/diagnostics.rs
@@ -18,7 +18,7 @@ fn unresolved_import() {
         r"
         use does_exist;
         use does_not_exist;
-          //^^^^^^^^^^^^^^ unresolved import
+      //^^^^^^^^^^^^^^^^^^^ UnresolvedImport
 
         mod does_exist {}
         ",
@@ -26,40 +26,13 @@ fn unresolved_import() {
 }
 
 #[test]
-fn unresolved_import_in_use_tree() {
-    // Only the relevant part of a nested `use` item should be highlighted.
-    check_diagnostics(
-        r"
-        use does_exist::{Exists, DoesntExist};
-                               //^^^^^^^^^^^ unresolved import
-
-        use {does_not_exist::*, does_exist};
-           //^^^^^^^^^^^^^^^^^ unresolved import
-
-        use does_not_exist::{
-            a,
-          //^ unresolved import
-            b,
-          //^ unresolved import
-            c,
-          //^ unresolved import
-        };
-
-        mod does_exist {
-            pub struct Exists;
-        }
-        ",
-    );
-}
-
-#[test]
 fn unresolved_extern_crate() {
     check_diagnostics(
         r"
         //- /main.rs crate:main deps:core
         extern crate core;
           extern crate doesnotexist;
-        //^^^^^^^^^^^^^^^^^^^^^^^^^^ unresolved extern crate
+        //^^^^^^^^^^^^^^^^^^^^^^^^^^ UnresolvedExternCrate
         //- /lib.rs crate:core
         ",
     );
@@ -72,7 +45,7 @@ fn extern_crate_self_as() {
         r"
         //- /lib.rs
           extern crate doesnotexist;
-        //^^^^^^^^^^^^^^^^^^^^^^^^^^ unresolved extern crate
+        //^^^^^^^^^^^^^^^^^^^^^^^^^^ UnresolvedExternCrate
         // Should not error.
         extern crate self as foo;
         struct Foo;
@@ -88,18 +61,18 @@ fn dedup_unresolved_import_from_unresolved_crate() {
         //- /main.rs crate:main
         mod a {
             extern crate doesnotexist;
-          //^^^^^^^^^^^^^^^^^^^^^^^^^^ unresolved extern crate
+          //^^^^^^^^^^^^^^^^^^^^^^^^^^ UnresolvedExternCrate
 
             // Should not error, since we already errored for the missing crate.
             use doesnotexist::{self, bla, *};
 
             use crate::doesnotexist;
-              //^^^^^^^^^^^^^^^^^^^ unresolved import
+          //^^^^^^^^^^^^^^^^^^^^^^^^ UnresolvedImport
         }
 
         mod m {
             use super::doesnotexist;
-              //^^^^^^^^^^^^^^^^^^^ unresolved import
+          //^^^^^^^^^^^^^^^^^^^^^^^^ UnresolvedImport
         }
         ",
     );
@@ -112,7 +85,7 @@ fn unresolved_module() {
         //- /lib.rs
         mod foo;
           mod bar;
-        //^^^^^^^^ unresolved module
+        //^^^^^^^^ UnresolvedModule
         mod baz {}
         //- /foo.rs
         ",
@@ -127,16 +100,16 @@ fn inactive_item() {
         r#"
         //- /lib.rs
           #[cfg(no)] pub fn f() {}
-        //^^^^^^^^^^^^^^^^^^^^^^^^ code is inactive due to #[cfg] directives: no is disabled
+        //^^^^^^^^^^^^^^^^^^^^^^^^ UnconfiguredCode
 
           #[cfg(no)] #[cfg(no2)] mod m;
-        //^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ code is inactive due to #[cfg] directives: no and no2 are disabled
+        //^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ UnconfiguredCode
 
           #[cfg(all(not(a), b))] enum E {}
-        //^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ code is inactive due to #[cfg] directives: b is disabled
+        //^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ UnconfiguredCode
 
           #[cfg(feature = "std")] use std;
-        //^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ code is inactive due to #[cfg] directives: feature = "std" is disabled
+        //^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ UnconfiguredCode
         "#,
     );
 }
@@ -149,14 +122,14 @@ fn inactive_via_cfg_attr() {
         r#"
         //- /lib.rs
           #[cfg_attr(not(never), cfg(no))] fn f() {}
-        //^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ code is inactive due to #[cfg] directives: no is disabled
+        //^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ UnconfiguredCode
 
           #[cfg_attr(not(never), cfg(not(no)))] fn f() {}
 
           #[cfg_attr(never, cfg(no))] fn g() {}
 
           #[cfg_attr(not(never), inline, cfg(no))] fn h() {}
-        //^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ code is inactive due to #[cfg] directives: no is disabled
+        //^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ UnconfiguredCode
         "#,
     );
 }
@@ -170,7 +143,7 @@ fn unresolved_legacy_scope_macro() {
 
           m!();
           m2!();
-        //^^^^^^ unresolved macro `self::m2!`
+        //^^^^^^ UnresolvedMacroCall
         "#,
     );
 }
@@ -187,7 +160,7 @@ fn unresolved_module_scope_macro() {
 
           self::m!();
           self::m2!();
-        //^^^^^^^^^^^^ unresolved macro `self::m2!`
+        //^^^^^^^^^^^^ UnresolvedMacroCall
         "#,
     );
 }