__builtin_object_size(ptr, type) returns -1 for type = {0,1} if there are any side-effects.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@92453 91177308-0d34-0410-b5e6-96231b3b80d8

lib/AST/ExprConstant.cpp

@@ -989,7 +989,7 @@ bool IntExprEvaluator::VisitCallExpr(const CallExpr *E) {
 
     // TODO: Perhaps we should let LLVM lower this?
     if (E->getArg(0)->HasSideEffects(Info.Ctx)) {
-      if (E->getArg(1)->EvaluateAsInt(Info.Ctx).getZExtValue() == 0)
+      if (E->getArg(1)->EvaluateAsInt(Info.Ctx).getZExtValue() <= 1)
         return Success(-1ULL, E);
       return Success(0, E);
     }

test/CodeGen/object-size.c

@@ -109,3 +109,14 @@ void test16() {
   // CHECK:       %call = call i8* @__inline_strcpy_chk(i8* %tmp1, i8* getelementptr inbounds ([9 x i8]* @.str, i32 0, i32 0))
   strcpy(gp += 1, "Hi there");
 }
+
+void test17() {
+  // CHECK: store i32 -1
+  gi = __builtin_object_size(gp++, 0);
+  // CHECK: store i32 -1
+  gi = __builtin_object_size(gp++, 1);
+  // CHECK: store i32 0
+  gi = __builtin_object_size(gp++, 2);
+  // CHECK: store i32 0
+  gi = __builtin_object_size(gp++, 3);
+}