[PCH] Clear switch case IDs when deserializing a objc method body.

Fixes rdar://11353109 & http://llvm.org/bugs/show_bug.cgi?id=12689

llvm-svn: 156056

clang/lib/Serialization/ASTReaderDecl.cpp

@@ -629,6 +629,8 @@ void ASTDeclReader::VisitObjCMethodDecl(ObjCMethodDecl *MD) {
   if (Record[Idx++]) {
     // In practice, this won't be executed (since method definitions
     // don't occur in header files).
+    // Switch case IDs are per method body.
+    Reader.ClearSwitchCaseIDs();
     MD->setBody(Reader.ReadStmt(F));
     MD->setSelfDecl(ReadDeclAs<ImplicitParamDecl>(Record, Idx));
     MD->setCmdDecl(ReadDeclAs<ImplicitParamDecl>(Record, Idx));

clang/test/PCH/objc_methods.h

@@ -9,3 +9,19 @@
 
 // FIXME: @compatibility_alias  AliasForTestPCH TestPCH;
 
+// http://llvm.org/PR12689
+@interface PR12689
+@end
+
+@implementation PR12689
+-(void)mugi:(int)x {
+  switch(x) {
+    case 23: {}
+  }
+}
+-(void)bonk:(int)x {
+  switch(x) {
+    case 42: {}
+  }
+}
+@end