Fix evatuated value of __builtin_object_size according to its
'type' argument when it cannot be determined which objects ptr
points to at compile time. rdar://18334276
llvm-svn: 218258
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 743e59f..0bd45da 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -6052,8 +6052,20 @@
return false;
}
- // If we can prove the base is null, lower to zero now.
- if (!Base.getLValueBase()) return Success(0, E);
+ if (!Base.getLValueBase()) {
+ // It is not possible to determine which objects ptr points to at compile time,
+ // __builtin_object_size should return (size_t) -1 for type 0 or 1
+ // and (size_t) 0 for type 2 or 3.
+ llvm::APSInt TypeIntVaue;
+ const Expr *ExprType = E->getArg(1);
+ if (!ExprType->EvaluateAsInt(TypeIntVaue, Info.Ctx))
+ return false;
+ if (TypeIntVaue == 0 || TypeIntVaue == 1)
+ return Success(-1, E);
+ if (TypeIntVaue == 2 || TypeIntVaue == 3)
+ return Success(0, E);
+ return Error(E);
+ }
QualType T = GetObjectType(Base.getLValueBase());
if (T.isNull() ||