3 files changed, 42 insertions, 11 deletions

diff --git a/crates/ide/src/diagnostics.rs b/crates/ide/src/diagnostics.rs
index 634e6a043..f7965326d 100644
--- a/crates/ide/src/diagnostics.rs
+++ b/crates/ide/src/diagnostics.rs
@@ -8,6 +8,7 @@ mod unresolved_module;
 mod unresolved_extern_crate;
 mod unresolved_import;
 mod unresolved_macro_call;
+mod unresolved_proc_macro;
 mod inactive_code;
 mod missing_fields;
 
@@ -68,6 +69,11 @@ impl Diagnostic {
         self
     }
 
+    fn severity(mut self, severity: Severity) -> Diagnostic {
+        self.severity = severity;
+        self
+    }
+
     fn error(range: TextRange, message: String) -> Self {
         Self {
             message,
@@ -178,16 +184,6 @@ pub(crate) fn diagnostics(
                     .with_code(Some(d.code())),
             );
         })
-        .on::<hir::diagnostics::UnresolvedProcMacro, _>(|d| {
-            // Use more accurate position if available.
-            let display_range = d
-                .precise_location
-                .unwrap_or_else(|| sema.diagnostics_display_range(d.display_source()).range);
-
-            // FIXME: it would be nice to tell the user whether proc macros are currently disabled
-            res.borrow_mut()
-                .push(Diagnostic::hint(display_range, d.message()).with_code(Some(d.code())));
-        })
         .on::<hir::diagnostics::UnimplementedBuiltinMacro, _>(|d| {
             let display_range = sema.diagnostics_display_range(d.display_source()).range;
             res.borrow_mut()
@@ -231,6 +227,7 @@ pub(crate) fn diagnostics(
             AnyDiagnostic::UnresolvedExternCrate(d) => unresolved_extern_crate::unresolved_extern_crate(&ctx, &d),
             AnyDiagnostic::UnresolvedImport(d) => unresolved_import::unresolved_import(&ctx, &d),
             AnyDiagnostic::UnresolvedMacroCall(d) => unresolved_macro_call::unresolved_macro_call(&ctx, &d),
+            AnyDiagnostic::UnresolvedProcMacro(d) => unresolved_proc_macro::unresolved_proc_macro(&ctx, &d),
             AnyDiagnostic::MissingFields(d) => missing_fields::missing_fields(&ctx, &d),
 
             AnyDiagnostic::InactiveCode(d) => match inactive_code::inactive_code(&ctx, &d) {
diff --git a/crates/ide/src/diagnostics/inactive_code.rs b/crates/ide/src/diagnostics/inactive_code.rs
index 52f97cb4c..afe333204 100644
--- a/crates/ide/src/diagnostics/inactive_code.rs
+++ b/crates/ide/src/diagnostics/inactive_code.rs
@@ -1,7 +1,10 @@
 use cfg::DnfExpr;
 use stdx::format_to;
 
-use crate::diagnostics::{Diagnostic, DiagnosticsContext};
+use crate::{
+    diagnostics::{Diagnostic, DiagnosticsContext},
+    Severity,
+};
 
 // Diagnostic: inactive-code
 //
@@ -27,6 +30,7 @@ pub(super) fn inactive_code(
         message,
         ctx.sema.diagnostics_display_range(d.node.clone()).range,
     )
+    .severity(Severity::WeakWarning)
     .with_unused(true);
     Some(res)
 }
diff --git a/crates/ide/src/diagnostics/unresolved_proc_macro.rs b/crates/ide/src/diagnostics/unresolved_proc_macro.rs
new file mode 100644
index 000000000..3dc6ab451
--- /dev/null
+++ b/crates/ide/src/diagnostics/unresolved_proc_macro.rs
@@ -0,0 +1,30 @@
+use crate::{
+    diagnostics::{Diagnostic, 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.enable`).
+pub(super) fn unresolved_proc_macro(
+    ctx: &DiagnosticsContext<'_>,
+    d: &hir::UnresolvedProcMacro,
+) -> Diagnostic {
+    // Use more accurate position if available.
+    let display_range = d
+        .precise_location
+        .unwrap_or_else(|| ctx.sema.diagnostics_display_range(d.node.clone()).range);
+    // FIXME: it would be nice to tell the user whether proc macros are currently disabled
+    let message = match &d.macro_name {
+        Some(name) => format!("proc macro `{}` not expanded", name),
+        None => "proc macro not expanded".to_string(),
+    };
+
+    Diagnostic::new("unresolved-proc-macro", message, display_range).severity(Severity::WeakWarning)
+}