r316032 - Fix PR34981, a crash-on-invalid merging dllimport to an invalid redecl.

[Nico Weber via cfe-commits]

Author: nico
Date: Tue Oct 17 14:14:02 2017
New Revision: 316032

URL: http://llvm.org/viewvc/llvm-project?rev=316032&view=rev
Log:
Fix PR34981, a crash-on-invalid merging dllimport to an invalid redecl.

This is basically like r288207, just the other way round.

Modified:
    cfe/trunk/lib/Sema/SemaDecl.cpp
    cfe/trunk/test/Sema/dllimport.c

Modified: cfe/trunk/lib/Sema/SemaDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDecl.cpp?rev=316032&r1=316031&r2=316032&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDecl.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDecl.cpp Tue Oct 17 14:14:02 2017
@@ -5975,7 +5975,7 @@ static void checkDLLAttributeRedeclarati
                                            NamedDecl *NewDecl,
                                            bool IsSpecialization,
                                            bool IsDefinition) {
-  if (OldDecl->isInvalidDecl())
+  if (OldDecl->isInvalidDecl() || NewDecl->isInvalidDecl())
     return;
 
   bool IsTemplate = false;
@@ -6081,7 +6081,8 @@ static void checkDLLAttributeRedeclarati
       NewDecl->dropAttr<DLLImportAttr>();
     }
   } else if (IsInline && OldImportAttr && !IsMicrosoft) {
-    // In MinGW, seeing a function declared inline drops the dllimport attribute.
+    // In MinGW, seeing a function declared inline drops the dllimport
+    // attribute.
     OldDecl->dropAttr<DLLImportAttr>();
     NewDecl->dropAttr<DLLImportAttr>();
     S.Diag(NewDecl->getLocation(),

Modified: cfe/trunk/test/Sema/dllimport.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/dllimport.c?rev=316032&r1=316031&r2=316032&view=diff
==============================================================================
--- cfe/trunk/test/Sema/dllimport.c (original)
+++ cfe/trunk/test/Sema/dllimport.c Tue Oct 17 14:14:02 2017
@@ -211,9 +211,14 @@ __declspec(dllimport) void redecl6();
                       void redecl7();
 __declspec(dllimport) inline void redecl7() {}
 
-// PR31069: Don't crash trying to merge attributes for redeclaration of invalid decl.
+// PR31069: Don't crash trying to merge attributes for redeclaration of invalid
+// decl.
 void __declspec(dllimport) redecl8(unknowntype X); // expected-error{{unknown type name 'unknowntype'}}
 void redecl8(unknowntype X) { } // expected-error{{unknown type name 'unknowntype'}}
+// PR32021: Similarly, don't crash trying to merge attributes from a valid
+// decl to an invalid redeclaration.
+void __declspec(dllimport) redecl9(void); // expected-note{{previous declaration is here}}
+int redecl9(void) {} // expected-error{{conflicting types for 'redecl9'}}
 
 // External linkage is required.
 __declspec(dllimport) static int staticFunc(); // expected-error{{'staticFunc' must have external linkage when declared 'dllimport'}}