Stop compilation if macro expansion failed

rust-lang · bors · Jul 27, 2025 · May 31, 2025 · Jul 23, 2025 · Jul 23, 2025
commit 96340f67146ff73fb3d308b848d8c7ed62888ca1
diff --git a/compiler/rustc_expand/src/base.rs b/compiler/rustc_expand/src/base.rs
@@ -1224,6 +1224,7 @@ pub struct ExtCtxt<'a> {
     pub(super) expanded_inert_attrs: MarkedAttrs,
     /// `-Zmacro-stats` data.
     pub macro_stats: FxHashMap<(Symbol, MacroKind), MacroStat>,
+    pub nb_macro_errors: usize,
 }
 
 impl<'a> ExtCtxt<'a> {
@@ -1254,6 +1255,7 @@ impl<'a> ExtCtxt<'a> {
             expanded_inert_attrs: MarkedAttrs::new(),
             buffered_early_lint: vec![],
             macro_stats: Default::default(),
+            nb_macro_errors: 0,
         }
     }
 
@@ -1315,6 +1317,12 @@ impl<'a> ExtCtxt<'a> {
         self.current_expansion.id.expansion_cause()
     }
 
+    /// This method increases the internal macro errors count and then call `trace_macros_diag`.
+    pub fn macro_error_and_trace_macros_diag(&mut self) {
+        self.nb_macro_errors += 1;
+        self.trace_macros_diag();
+    }
+
     pub fn trace_macros_diag(&mut self) {
         for (span, notes) in self.expansions.iter() {
             let mut db = self.dcx().create_note(errors::TraceMacro { span: *span });

diff --git a/compiler/rustc_expand/src/expand.rs b/compiler/rustc_expand/src/expand.rs
@@ -693,7 +693,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
             crate_name: self.cx.ecfg.crate_name,
         });
 
-        self.cx.trace_macros_diag();
+        self.cx.macro_error_and_trace_macros_diag();
         guar
     }
 
@@ -707,7 +707,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
     ) -> ErrorGuaranteed {
         let guar =
             self.cx.dcx().emit_err(WrongFragmentKind { span, kind: kind.name(), name: &mac.path });
-        self.cx.trace_macros_diag();
+        self.cx.macro_error_and_trace_macros_diag();
         guar
     }
 
@@ -1048,7 +1048,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
                 }
                 annotate_err_with_kind(&mut err, kind, span);
                 let guar = err.emit();
-                self.cx.trace_macros_diag();
+                self.cx.macro_error_and_trace_macros_diag();
                 kind.dummy(span, guar)
             }
         }

diff --git a/compiler/rustc_expand/src/mbe/macro_parser.rs b/compiler/rustc_expand/src/mbe/macro_parser.rs
@@ -299,6 +299,7 @@ enum EofMatcherPositions {
 }
 
 /// Represents the possible results of an attempted parse.
+#[derive(Debug)]
 pub(crate) enum ParseResult<T, F> {
     /// Parsed successfully.
     Success(T),

diff --git a/compiler/rustc_expand/src/mbe/macro_rules.rs b/compiler/rustc_expand/src/mbe/macro_rules.rs
@@ -280,7 +280,7 @@ fn expand_macro<'cx>(
             // Retry and emit a better error.
             let (span, guar) =
                 diagnostics::failed_to_match_macro(cx.psess(), sp, def_span, name, arg, rules);
-            cx.trace_macros_diag();
+            cx.macro_error_and_trace_macros_diag();
             DummyResult::any(span, guar)
         }
     }

diff --git a/compiler/rustc_interface/src/passes.rs b/compiler/rustc_interface/src/passes.rs
@@ -208,6 +208,10 @@ fn configure_and_expand(
         // Expand macros now!
         let krate = sess.time("expand_crate", || ecx.monotonic_expander().expand_crate(krate));
 
+        if ecx.nb_macro_errors > 0 {
+            sess.dcx().abort_if_errors();
+        }
+
         // The rest is error reporting and stats
 
         sess.psess.buffered_lints.with_lock(|buffered_lints: &mut Vec<BufferedEarlyLint>| {