[PATCH] D12000: Bugfix - Clang handles __builtin_object_size in wrong way
Richard Smith via cfe-commits
cfe-commits at lists.llvm.org
Fri Aug 14 17:11:43 PDT 2015
rsmith added a subscriber: rsmith.
================
Comment at: lib/AST/ExprConstant.cpp:6221-6223
@@ +6220,5 @@
+ //
+ // extern struct X { char buff[32]; int a, b, c; } *p;
+ // int a = __builtin_object_size(p->buff + 4, 3); // returns 28
+ // int b = __builtin_object_size(p->buff + 4, 2); // returns 0, not 40
+ //
----------------
Please add a testcase like this (where the base object is unknown but the designator is known, and thus we can compute the Type == 1 and Type == 3 forms but not the Type == 0 and Type == 2 forms).
================
Comment at: lib/AST/ExprConstant.cpp:6243-6245
@@ +6242,5 @@
+ } else if (End.Designator.IsOnePastTheEnd) {
+ // We're already pointing at the end of the object.
+ AmountToAdd = 0;
+ }
+
----------------
Please add testcases for the pointer-to-the-end case:
int n;
static_assert(__builtin_object_size(&n + 1, 1) == 0);
struct X { int a, b, c; } x;
static_assert(__builtin_object_size(&x.a + 1, 1) == 0);
http://reviews.llvm.org/D12000
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