Fix crash when both ExpectAndConsume and ConsumeAnyToken emit diagnostics

The DiagnosticBuilder's lifetime in parser typo recovery was overlapping with
the subsequent consume which can itself emit PP diagnostics.

Patch by Olivier Goffart!

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@201965 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Parse/Parser.cpp b/lib/Parse/Parser.cpp
index 71f5b845ddd3bc29b0e05100f584f325dfa09352..b76d430f17645fecdd9a1170386c4d905fe22f30 100644 (file)
--- a/lib/Parse/Parser.cpp
+++ b/lib/Parse/Parser.cpp
@@ -118,18 +118,20 @@ bool Parser::ExpectAndConsume(tok::TokenKind ExpectedTok, unsigned DiagID,
   // Detect common single-character typos and resume.
   if (IsCommonTypo(ExpectedTok, Tok)) {
     SourceLocation Loc = Tok.getLocation();
-    DiagnosticBuilder DB = Diag(Loc, DiagID);
-    DB << FixItHint::CreateReplacement(SourceRange(Loc),
-                                       getPunctuatorSpelling(ExpectedTok));
-    if (DiagID == diag::err_expected)
-      DB << ExpectedTok;
-    else if (DiagID == diag::err_expected_after)
-      DB << Msg << ExpectedTok;
-    else
-      DB << Msg;
-    ConsumeAnyToken();
+    {
+      DiagnosticBuilder DB = Diag(Loc, DiagID);
+      DB << FixItHint::CreateReplacement(
+                SourceRange(Loc), tok::getPunctuatorSpelling(ExpectedTok));
+      if (DiagID == diag::err_expected)
+        DB << ExpectedTok;
+      else if (DiagID == diag::err_expected_after)
+        DB << Msg << ExpectedTok;
+      else
+        DB << Msg;
+    }
 
     // Pretend there wasn't a problem.
+    ConsumeAnyToken();
     return false;
   }
 

diff --git a/test/Parser/diag-crash.c b/test/Parser/diag-crash.c
new file mode 100644 (file)
index 0000000..4f1265f
--- /dev/null
+++ b/test/Parser/diag-crash.c
@@ -0,0 +1,6 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+
+// Avoid preprocessor diag crash caused by a parser diag left in flight.
+
+int foo: // expected-error {{expected ';' after top level declarator}}
+#endif   // expected-error {{#endif without #if}}