First pass at implementing C++ enum semantics: calculate (and store) an

"integer promotion" type associated with an enum decl, and use this type to
determine which type to promote to.  This type obeys C++ [conv.prom]p2 and
is therefore generally signed unless the range of the enumerators forces
it to be unsigned.

Kills off a lot of false positives from -Wsign-compare in C++, addressing
rdar://7455616




git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@90965 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 4 insertions, 1 deletions

diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
index 42c9ef948c..212dd353c3 100644
--- a/lib/AST/Decl.cpp
+++ b/lib/AST/Decl.cpp
@@ -195,9 +195,12 @@ void EnumDecl::Destroy(ASTContext& C) {
   Decl::Destroy(C);
 }
 
-void EnumDecl::completeDefinition(ASTContext &C, QualType NewType) {
+void EnumDecl::completeDefinition(ASTContext &C,
+                                  QualType NewType,
+                                  QualType NewPromotionType) {
   assert(!isDefinition() && "Cannot redefine enums!");
   IntegerType = NewType;
+  PromotionType = NewPromotionType;
   TagDecl::completeDefinition();
 }