r200815 - Don't mark decls with mismatching exception specs invalid in MS mode (PR18683)

[Hans Wennborg]

Author: hans
Date: Tue Feb  4 20:37:58 2014
New Revision: 200815

URL: http://llvm.org/viewvc/llvm-project?rev=200815&view=rev
Log:
Don't mark decls with mismatching exception specs invalid in MS mode (PR18683)

We accept these with a warning in MS mode, but we would previously mark them
invalid, causing us not to emit code for them.

Differential Revision: http://llvm-reviews.chandlerc.com/D2681

Added:
    cfe/trunk/test/CodeGenCXX/pr18661.cpp
Modified:
    cfe/trunk/lib/Sema/SemaExceptionSpec.cpp

Modified: cfe/trunk/lib/Sema/SemaExceptionSpec.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExceptionSpec.cpp?rev=200815&r1=200814&r2=200815&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaExceptionSpec.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExceptionSpec.cpp Tue Feb  4 20:37:58 2014
@@ -155,9 +155,13 @@ bool Sema::CheckEquivalentExceptionSpec(
   bool IsOperatorNew = OO == OO_New || OO == OO_Array_New;
   bool MissingExceptionSpecification = false;
   bool MissingEmptyExceptionSpecification = false;
+
   unsigned DiagID = diag::err_mismatched_exception_spec;
-  if (getLangOpts().MicrosoftExt)
+  bool ReturnValueOnError = true;
+  if (getLangOpts().MicrosoftExt) {
     DiagID = diag::warn_mismatched_exception_spec; 
+    ReturnValueOnError = false;
+  }
 
   // Check the types as written: they must match before any exception
   // specification adjustment is applied.
@@ -182,9 +186,9 @@ bool Sema::CheckEquivalentExceptionSpec(
   }
 
   // The failure was something other than an missing exception
-  // specification; return an error.
+  // specification; return an error, except in MS mode where this is a warning.
   if (!MissingExceptionSpecification)
-    return true;
+    return ReturnValueOnError;
 
   const FunctionProtoType *NewProto =
     New->getType()->castAs<FunctionProtoType>();
@@ -302,10 +306,14 @@ bool Sema::CheckEquivalentExceptionSpec(
     const FunctionProtoType *New, SourceLocation NewLoc) {
   unsigned DiagID = diag::err_mismatched_exception_spec;
   if (getLangOpts().MicrosoftExt)
-    DiagID = diag::warn_mismatched_exception_spec; 
-  return CheckEquivalentExceptionSpec(PDiag(DiagID),
-                                      PDiag(diag::note_previous_declaration),
-                                      Old, OldLoc, New, NewLoc);
+    DiagID = diag::warn_mismatched_exception_spec;
+  bool Result = CheckEquivalentExceptionSpec(PDiag(DiagID),
+      PDiag(diag::note_previous_declaration), Old, OldLoc, New, NewLoc);
+
+  // In Microsoft mode, mismatching exception specifications just cause a warning.
+  if (getLangOpts().MicrosoftExt)
+    return false;
+  return Result;
 }
 
 /// CheckEquivalentExceptionSpec - Check if the two types have compatible

Added: cfe/trunk/test/CodeGenCXX/pr18661.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/pr18661.cpp?rev=200815&view=auto
==============================================================================
--- cfe/trunk/test/CodeGenCXX/pr18661.cpp (added)
+++ cfe/trunk/test/CodeGenCXX/pr18661.cpp Tue Feb  4 20:37:58 2014
@@ -0,0 +1,14 @@
+// RUN: %clang_cc1 %s -triple %itanium_abi_triple -fcxx-exceptions -fms-extensions -emit-llvm -o - | FileCheck %s
+
+extern "C" {
+  void f();
+
+  // In MS mode we don't validate the exception specification.
+  void f() throw() {
+  }
+}
+
+// PR18661: Clang would fail to emit function definition with mismatching
+// exception specification, even though it was just treated as a warning.
+
+// CHECK: define void @f()