[AIX][libcxx] AIX system headers need stdint.h and inttypes.h to be re-enterable when macro _STD_TYPES_T is defined

[xingxue]

Summary

AIX system headers need stdint.h and inttypes.h to be re-enterable when macro _STD_TYPES_T is defined so that limit macro definitions such as UINT32_MAX can be found.

[mclow.lists]

I see no tests here.

[xingxue]

Added test case stdint_h.sh.cpp.

[mclow.lists]

libcxx/include/stdint.h

17

I don't think that this will do what you want it to.
Is this a supported use case?

#include <stdint.h>
#define _STD_TYPES_T
#include <stdint.h>

[hubert.reinterpretcast]

libcxx/include/stdint.h

17

The comment is perhaps not clear. We need <stdint.h> to be re-enterable only as long as all previous inclusions have occurred while _STD_TYPES_T is defined. The effect of including <stdint.h> without defining _STD_TYPES_T is a strict superset of the effects of including <stdint.h> in other circumstances. Should we adjust the comment?

[xingxue]

Updated comments explaining the scenario of the changes.

[xingxue]

libcxx/include/stdint.h

17

Updated comments as suggested. This patch helps scenarios such as the following on AIX.

#include <sys/types.h>
#include <stdint.h>

where <sys/types.h> included in the first line defines macro _STD_TYPES_T, includes <stdint.h>, and then undefines _STD_TYPES_T. <stdint.h> included in the second line can be entered to get to macros such as UINT32_MAX. Since _STD_TYPES_T is undefined with the second inclusion, the header guard macro is defined and <stdint.h> is no longer re-enterable.

[hubert.reinterpretcast]

LGTM with minor comment.

libcxx/test/std/depr/depr.c.headers/stdint_h.sh.cpp

22

Typo:
s/_XOPEN_SOUECE/_XOPEN_SOURCE/;

[xingxue]

Addressed comments:

• Fixed typo _XOPEN_SOUECE->_XOPEN_SOURCE

[xingxue]

libcxx/test/std/depr/depr.c.headers/stdint_h.sh.cpp

22

Good catch! Fixed.

[xingxue]

Hi @mclow.lists, Do you have any further comments?

[hubert.reinterpretcast]

LGTM.

[sylvestre.ledru]

FYI, I had similar patches for Linux/Debian packaging.
Thanks!

clang/lib/Headers/inttypes.h

 \*===----------------------------------------------------------------------===*/
 
 #ifndef __CLANG_INTTYPES_H
+// AIX system headers need inttypes.h to be re-enterable while _STD_TYPES_T
+// is defined until an inclusion of it without _STD_TYPES_T occurs, in which
+// case the header guard macro is defined.
+#if !defined(_AIX) || !defined(_STD_TYPES_T)
 #define __CLANG_INTTYPES_H
+#endif
 
 #if defined(_MSC_VER) && _MSC_VER < 1800
 #error MSVC does not have inttypes.h prior to Visual Studio 2013

clang/lib/Headers/stdint.h

 \*===----------------------------------------------------------------------===*/
 
 #ifndef __CLANG_STDINT_H
+// AIX system headers need stdint.h to be re-enterable while _STD_TYPES_T
+// is defined until an inclusion of it without _STD_TYPES_T occurs, in which
+// case the header guard macro is defined.
+#if !defined(_AIX) || !defined(_STD_TYPES_T) || !defined(__STDC_HOSTED__)
 #define __CLANG_STDINT_H
+#endif
 
 /* If we're hosted, fall back to the system's stdint.h, which might have
  * additional definitions.

libcxx/include/inttypes.h

 //===----------------------------------------------------------------------===//
 
 #ifndef _LIBCPP_INTTYPES_H
+// AIX system headers need inttypes.h to be re-enterable while _STD_TYPES_T
+// is defined until an inclusion of it without _STD_TYPES_T occurs, in which
+// case the header guard macro is defined.
+#if !defined(_AIX) || !defined(_STD_TYPES_T)
 #define _LIBCPP_INTTYPES_H
+#endif // _STD_TYPES_T
 
 /*
     inttypes.h synopsis

libcxx/include/stdint.h

 //===----------------------------------------------------------------------===//
 
 #ifndef _LIBCPP_STDINT_H
+// AIX system headers need stdint.h to be re-enterable while _STD_TYPES_T
+// is defined until an inclusion of it without _STD_TYPES_T occurs, in which
+// case the header guard macro is defined.
+#if !defined(_AIX) || !defined(_STD_TYPES_T)
 #define _LIBCPP_STDINT_H
+#endif // _STD_TYPES_T
 
 /*
     stdint.h synopsis

libcxx/test/std/depr/depr.c.headers/stdint_h.sh.cpp

+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// AIX system headers need stdint.h to be re-enterable when macro _STD_TYPES_T
+// is defined. This test case tests that after including sys/types.h which
+// defines macro _STD_TYPES_T, includes stdint.h, and then undefines
+// _STD_TYPES_T, stdint.h can be entered to get to macros like UINT32_MAX.
+//
+// REQUIRES: aix
+// RUN: %compile -c
+// RUN: %compile -c -D_XOPEN_SOURCE=700
+
+// test <stdint.h>
+//
+// Test that limits macros are available when <stdint.h> is included with
+// or without macro _XOPEN_SOURCE=700.
+
+#include <sys/types.h>
+#include <stdint.h>
+
+#ifndef INT8_MIN
+#error INT8_MIN not defined
+#endif
+
+#ifndef INT16_MIN
+#error INT16_MIN not defined
+#endif
+
+#ifndef INT32_MIN
+#error INT32_MIN not defined
+#endif
+
+#ifndef INT64_MIN
+#error INT64_MIN not defined
+#endif
+
+#ifndef INT8_MAX
+#error INT8_MAX not defined
+#endif
+
+#ifndef INT16_MAX
+#error INT16_MAX not defined
+#endif
+
+#ifndef INT32_MAX
+#error INT32_MAX not defined
+#endif
+
+#ifndef INT64_MAX
+#error INT64_MAX not defined
+#endif
+
+#ifndef UINT8_MAX
+#error UINT8_MAX not defined
+#endif
+
+#ifndef UINT16_MAX
+#error UINT16_MAX not defined
+#endif
+
+#ifndef UINT32_MAX
+#error UINT32_MAX not defined
+#endif
+
+#ifndef UINT64_MAX
+#error UINT64_MAX not defined
+#endif
+
+#ifndef INT_LEAST8_MIN
+#error INT_LEAST8_MIN not defined
+#endif
+
+#ifndef INT_LEAST16_MIN
+#error INT_LEAST16_MIN not defined
+#endif
+
+#ifndef INT_LEAST32_MIN
+#error INT_LEAST32_MIN not defined
+#endif
+
+#ifndef INT_LEAST64_MIN
+#error INT_LEAST64_MIN not defined
+#endif
+
+#ifndef INT_LEAST8_MAX
+#error INT_LEAST8_MAX not defined
+#endif
+
+#ifndef INT_LEAST16_MAX
+#error INT_LEAST16_MAX not defined
+#endif
+
+#ifndef INT_LEAST32_MAX
+#error INT_LEAST32_MAX not defined
+#endif
+
+#ifndef INT_LEAST64_MAX
+#error INT_LEAST64_MAX not defined
+#endif
+
+#ifndef UINT_LEAST8_MAX
+#error UINT_LEAST8_MAX not defined
+#endif
+
+#ifndef UINT_LEAST16_MAX
+#error UINT_LEAST16_MAX not defined
+#endif
+
+#ifndef UINT_LEAST32_MAX
+#error UINT_LEAST32_MAX not defined
+#endif
+
+#ifndef UINT_LEAST64_MAX
+#error UINT_LEAST64_MAX not defined
+#endif
+
+#ifndef INT_FAST8_MIN
+#error INT_FAST8_MIN not defined
+#endif
+
+#ifndef INT_FAST16_MIN
+#error INT_FAST16_MIN not defined
+#endif
+
+#ifndef INT_FAST32_MIN
+#error INT_FAST32_MIN not defined
+#endif
+
+#ifndef INT_FAST64_MIN
+#error INT_FAST64_MIN not defined
+#endif
+
+#ifndef INT_FAST8_MAX
+#error INT_FAST8_MAX not defined
+#endif
+
+#ifndef INT_FAST16_MAX
+#error INT_FAST16_MAX not defined
+#endif
+
+#ifndef INT_FAST32_MAX
+#error INT_FAST32_MAX not defined
+#endif
+
+#ifndef INT_FAST64_MAX
+#error INT_FAST64_MAX not defined
+#endif
+
+#ifndef UINT_FAST8_MAX
+#error UINT_FAST8_MAX not defined
+#endif
+
+#ifndef UINT_FAST16_MAX
+#error UINT_FAST16_MAX not defined
+#endif
+
+#ifndef UINT_FAST32_MAX
+#error UINT_FAST32_MAX not defined
+#endif
+
+#ifndef UINT_FAST64_MAX
+#error UINT_FAST64_MAX not defined
+#endif
+
+#ifndef INTPTR_MIN
+#error INTPTR_MIN not defined
+#endif
+
+#ifndef INTPTR_MAX
+#error INTPTR_MAX not defined
+#endif
+
+#ifndef UINTPTR_MAX
+#error UINTPTR_MAX not defined
+#endif
+
+#ifndef INTMAX_MIN
+#error INTMAX_MIN not defined
+#endif
+
+#ifndef INTMAX_MAX
+#error INTMAX_MAX not defined
+#endif
+
+#ifndef UINTMAX_MAX
+#error UINTMAX_MAX not defined
+#endif
+
+#ifndef PTRDIFF_MIN
+#error PTRDIFF_MIN not defined
+#endif
+
+#ifndef PTRDIFF_MAX
+#error PTRDIFF_MAX not defined
+#endif
+
+#ifndef SIG_ATOMIC_MIN
+#error SIG_ATOMIC_MIN not defined
+#endif
+
+#ifndef SIG_ATOMIC_MAX
+#error SIG_ATOMIC_MAX not defined
+#endif
+
+#ifndef SIZE_MAX
+#error SIZE_MAX not defined
+#endif
+
+#ifndef WCHAR_MIN
+#error WCHAR_MIN not defined
+#endif
+
+#ifndef WCHAR_MAX
+#error WCHAR_MAX not defined
+#endif
+
+#ifndef WINT_MIN
+#error WINT_MIN not defined
+#endif
+
+#ifndef WINT_MAX
+#error WINT_MAX not defined
+#endif
+
+#ifndef INT8_C
+#error INT8_C not defined
+#endif
+
+#ifndef INT16_C
+#error INT16_C not defined
+#endif
+
+#ifndef INT32_C
+#error INT32_C not defined
+#endif
+
+#ifndef INT64_C
+#error INT64_C not defined
+#endif
+
+#ifndef UINT8_C
+#error UINT8_C not defined
+#endif
+
+#ifndef UINT16_C
+#error UINT16_C not defined
+#endif
+
+#ifndef UINT32_C
+#error UINT32_C not defined
+#endif
+
+#ifndef UINT64_C
+#error UINT64_C not defined
+#endif
+
+#ifndef INTMAX_C
+#error INTMAX_C not defined
+#endif
+
+#ifndef UINTMAX_C
+#error UINTMAX_C not defined
+#endif