builtin-object-size-cxx14.cpp
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// RUN: %clang_cc1 -fsyntax-only -verify=expected,cxx14 -std=c++14 %s
// RUN: %clang_cc1 -fsyntax-only -verify -std=c++2a %s
typedef __SIZE_TYPE__ size_t;
namespace basic {
// Ensuring that __bos can be used in constexpr functions without anything
// sketchy going on...
constexpr int bos0() {
int k = 5;
char cs[10] = {};
return __builtin_object_size(&cs[k], 0);
}
constexpr int bos1() {
int k = 5;
char cs[10] = {};
return __builtin_object_size(&cs[k], 1);
}
constexpr int bos2() {
int k = 5;
char cs[10] = {};
return __builtin_object_size(&cs[k], 2);
}
constexpr int bos3() {
int k = 5;
char cs[10] = {};
return __builtin_object_size(&cs[k], 3);
}
static_assert(bos0() == sizeof(char) * 5, "");
static_assert(bos1() == sizeof(char) * 5, "");
static_assert(bos2() == sizeof(char) * 5, "");
static_assert(bos3() == sizeof(char) * 5, "");
}
namespace in_enable_if {
// The code that prompted these changes was __bos in enable_if
void copy5CharsInto(char *buf) // expected-note{{candidate}}
__attribute__((enable_if(__builtin_object_size(buf, 0) != -1 &&
__builtin_object_size(buf, 0) > 5,
"")));
// We use different EvalModes for __bos with type 0 versus 1. Ensure 1 works,
// too...
void copy5CharsIntoStrict(char *buf) // expected-note{{candidate}}
__attribute__((enable_if(__builtin_object_size(buf, 1) != -1 &&
__builtin_object_size(buf, 1) > 5,
"")));
struct LargeStruct {
int pad;
char buf[6];
int pad2;
};
struct SmallStruct {
int pad;
char buf[5];
int pad2;
};
void noWriteToBuf() {
char buf[6];
copy5CharsInto(buf);
LargeStruct large;
copy5CharsIntoStrict(large.buf);
}
void initTheBuf() {
char buf[6] = {};
copy5CharsInto(buf);
LargeStruct large = {0, {}, 0};
copy5CharsIntoStrict(large.buf);
}
int getI();
void initTheBufWithALoop() {
char buf[6] = {};
for (unsigned I = getI(); I != sizeof(buf); ++I)
buf[I] = I;
copy5CharsInto(buf);
LargeStruct large;
for (unsigned I = getI(); I != sizeof(buf); ++I)
large.buf[I] = I;
copy5CharsIntoStrict(large.buf);
}
void tooSmallBuf() {
char buf[5];
copy5CharsInto(buf); // expected-error{{no matching function for call}}
SmallStruct small;
copy5CharsIntoStrict(small.buf); // expected-error{{no matching function for call}}
}
}
namespace InvalidBase {
// Ensure this doesn't crash.
struct S { const char *name; };
S invalid_base();
constexpr size_t bos_name = __builtin_object_size(invalid_base().name, 1);
static_assert(bos_name == -1, "");
struct T { ~T(); };
T invalid_base_2();
constexpr size_t bos_dtor = __builtin_object_size(&(T&)(T&&)invalid_base_2(), 0);
static_assert(bos_dtor == -1, "");
}
// PR44268
constexpr int bos_new() { // cxx14-error {{constant expression}}
void *p = new int; // cxx14-note {{until C++20}}
return __builtin_object_size(p, 0);
}