Fix for PR7911 and PR7921: make isIntegralOrEnumerationType return false

for incomplete enum types.  An incomplete enum can't really be treated as
an "integral or enumeration" type, and the incorrect treatment leads to
bad behavior for many callers.

This makes isIntegralOrEnumerationType equivalent to isIntegerType; I think
we should globally replace the latter with the former; thoughts?



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@111512 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 18 insertions, 4 deletions

diff --git a/lib/AST/Type.cpp b/lib/AST/Type.cpp
index 4ab463699c..c2fc69fd2d 100644
--- a/lib/AST/Type.cpp
+++ b/lib/AST/Type.cpp
@@ -460,10 +460,13 @@ bool Type::isIntegralOrEnumerationType() const {
   if (const BuiltinType *BT = dyn_cast<BuiltinType>(CanonicalType))
     return BT->getKind() >= BuiltinType::Bool &&
            BT->getKind() <= BuiltinType::Int128;
-  
-  if (isa<EnumType>(CanonicalType))
-    return true;
-  
+
+  // Check for a complete enum type; incomplete enum types are not properly an
+  // enumeration type in the sense required here.
+  if (const TagType *TT = dyn_cast<TagType>(CanonicalType))
+    if (TT->getDecl()->isEnum() && TT->getDecl()->isDefinition())
+      return true;
+
   return false;  
 }
 
diff --git a/test/Sema/enum.c b/test/Sema/enum.c
index 057015011e..64aa31bc4b 100644
--- a/test/Sema/enum.c
+++ b/test/Sema/enum.c
@@ -96,3 +96,9 @@ char * s = (an_enum) an_enumerator; // expected-warning {{incompatible integer t
 // PR4515
 enum PR4515 {PR4515a=1u,PR4515b=(PR4515a-2)/2};
 int CheckPR4515[PR4515b==0?1:-1];
+
+// PR7911
+extern enum PR7911T PR7911V; // expected-warning{{ISO C forbids forward references to 'enum' types}}
+void PR7911F() {
+  switch (PR7911V); // expected-error {{statement requires expression of integer type}}
+}
diff --git a/test/SemaCXX/enum.cpp b/test/SemaCXX/enum.cpp
index 0690ead250..1dc55e3916 100644
--- a/test/SemaCXX/enum.cpp
+++ b/test/SemaCXX/enum.cpp
@@ -85,3 +85,8 @@ namespace PR7051 {
 // PR7466
 enum { }; // expected-warning{{declaration does not declare anything}}
 typedef enum { }; // expected-warning{{typedef requires a name}}
+
+// PR7921
+enum PR7921E {
+    PR7921V = (PR7921E)(123) // expected-error {{expression is not an integer constant expression}}
+};