[include] Declare __STDC_*_MACROS for C++11 compat in old libc

Declare __STDC_FORMAT_MACROS, __STDC_LIMIT_MACROS and
__STDC_CONSTANT_MACROS before including real inttypes.h/stdint.h when
the wrapper-header is included in C++11, in order to enable
the necessary macros in C99-compliant libc.

The C99 standard defined that the format macros in inttypes.h should be
defined by the C++ implementations only when __STDC_FORMAT_MACROS is
defined, and the limit and constant macros in stdint.h should be defined
only when __STDC_LIMIT_MACROS and __STDC_CONSTANT_MACROS are defined
appropriately. Following this specification, multiple old versions of
glibc up to 2.17 do not define those macros by default for C++,
rendering the libc++ headers non-compliant to the C++11 standard.

In order to achieve the necessary compliance, __STDC_FORMAT_MACROS is
defined in wrapped inttypes.h just before including the system
inttypes.h, when C++11 or newer is used. Both __STDC_LIMIT_MACROS
and __STDC_CONSTANT_MACROS are defined in newly-wrapped stdint.h. This
fixes the C++11 compliance while preserving the current behavior for
C++03.

Differential Revision: https://reviews.llvm.org/D24903

llvm-svn: 282435

libcxx/include/inttypes.h

@@ -237,6 +237,13 @@ uintmax_t wcstoumax(const wchar_t* restrict nptr, wchar_t** restrict endptr, int
 #pragma GCC system_header
 #endif
 
+/* C99 stdlib (e.g. glibc < 2.18) does not provide format macros needed
+   for C++11 unless __STDC_FORMAT_MACROS is defined
+*/
+#if defined(__cplusplus) && !defined(__STDC_FORMAT_MACROS)
+#   define __STDC_FORMAT_MACROS
+#endif
+
 #include_next <inttypes.h>
 
 #ifdef __cplusplus

libcxx/include/stdint.h

@@ -0,0 +1,121 @@
+// -*- C++ -*-
+//===---------------------------- stdint.h --------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_STDINT_H
+#define _LIBCPP_STDINT_H
+
+/*
+    stdint.h synopsis
+
+Macros:
+
+    INT8_MIN
+    INT16_MIN
+    INT32_MIN
+    INT64_MIN
+
+    INT8_MAX
+    INT16_MAX
+    INT32_MAX
+    INT64_MAX
+
+    UINT8_MAX
+    UINT16_MAX
+    UINT32_MAX
+    UINT64_MAX
+
+    INT_LEAST8_MIN
+    INT_LEAST16_MIN
+    INT_LEAST32_MIN
+    INT_LEAST64_MIN
+
+    INT_LEAST8_MAX
+    INT_LEAST16_MAX
+    INT_LEAST32_MAX
+    INT_LEAST64_MAX
+
+    UINT_LEAST8_MAX
+    UINT_LEAST16_MAX
+    UINT_LEAST32_MAX
+    UINT_LEAST64_MAX
+
+    INT_FAST8_MIN
+    INT_FAST16_MIN
+    INT_FAST32_MIN
+    INT_FAST64_MIN
+
+    INT_FAST8_MAX
+    INT_FAST16_MAX
+    INT_FAST32_MAX
+    INT_FAST64_MAX
+
+    UINT_FAST8_MAX
+    UINT_FAST16_MAX
+    UINT_FAST32_MAX
+    UINT_FAST64_MAX
+
+    INTPTR_MIN
+    INTPTR_MAX
+    UINTPTR_MAX
+
+    INTMAX_MIN
+    INTMAX_MAX
+
+    UINTMAX_MAX
+
+    PTRDIFF_MIN
+    PTRDIFF_MAX
+
+    SIG_ATOMIC_MIN
+    SIG_ATOMIC_MAX
+
+    SIZE_MAX
+
+    WCHAR_MIN
+    WCHAR_MAX
+
+    WINT_MIN
+    WINT_MAX
+
+    INT8_C(value)
+    INT16_C(value)
+    INT32_C(value)
+    INT64_C(value)
+
+    UINT8_C(value)
+    UINT16_C(value)
+    UINT32_C(value)
+    UINT64_C(value)
+
+    INTMAX_C(value)
+    UINTMAX_C(value)
+
+*/
+
+#include <__config>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+/* C99 stdlib (e.g. glibc < 2.18) does not provide macros needed
+   for C++11 unless __STDC_LIMIT_MACROS and __STDC_CONSTANT_MACROS
+   are defined
+*/
+#if defined(__cplusplus) && !defined(__STDC_LIMIT_MACROS)
+#   define __STDC_LIMIT_MACROS
+#endif
+#if defined(__cplusplus) && !defined(__STDC_CONSTANT_MACROS)
+#   define __STDC_CONSTANT_MACROS
+#endif
+
+#include_next <stdint.h>
+
+#endif  // _LIBCPP_STDINT_H