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Diffstat (limited to 'gl/m4/gnulib-common.m4')
| -rw-r--r-- | gl/m4/gnulib-common.m4 | 1434 |
1 files changed, 1434 insertions, 0 deletions
diff --git a/gl/m4/gnulib-common.m4 b/gl/m4/gnulib-common.m4 new file mode 100644 index 0000000..2426eb6 --- /dev/null +++ b/gl/m4/gnulib-common.m4 @@ -0,0 +1,1434 @@ +# gnulib-common.m4 serial 87 +dnl Copyright (C) 2007-2023 Free Software Foundation, Inc. +dnl This file is free software; the Free Software Foundation +dnl gives unlimited permission to copy and/or distribute it, +dnl with or without modifications, as long as this notice is preserved. + +AC_PREREQ([2.62]) + +# gl_COMMON +# is expanded unconditionally through gnulib-tool magic. +AC_DEFUN([gl_COMMON], [ + dnl Use AC_REQUIRE here, so that the code is expanded once only. + AC_REQUIRE([gl_00GNULIB]) + AC_REQUIRE([gl_COMMON_BODY]) + AC_REQUIRE([gl_ZZGNULIB]) +]) +AC_DEFUN([gl_COMMON_BODY], [ + AH_VERBATIM([0witness], +[/* Witness that <config.h> has been included. */ +#define _GL_CONFIG_H_INCLUDED 1 +]) + AH_VERBATIM([_GL_GNUC_PREREQ], +[/* True if the compiler says it groks GNU C version MAJOR.MINOR. */ +#if defined __GNUC__ && defined __GNUC_MINOR__ +# define _GL_GNUC_PREREQ(major, minor) \ + ((major) < __GNUC__ + ((minor) <= __GNUC_MINOR__)) +#else +# define _GL_GNUC_PREREQ(major, minor) 0 +#endif +]) + AH_VERBATIM([_Noreturn], +[/* The _Noreturn keyword of C11. */ +#ifndef _Noreturn +# if (defined __cplusplus \ + && ((201103 <= __cplusplus && !(__GNUC__ == 4 && __GNUC_MINOR__ == 7)) \ + || (defined _MSC_VER && 1900 <= _MSC_VER)) \ + && 0) + /* [[noreturn]] is not practically usable, because with it the syntax + extern _Noreturn void func (...); + would not be valid; such a declaration would only be valid with 'extern' + and '_Noreturn' swapped, or without the 'extern' keyword. However, some + AIX system header files and several gnulib header files use precisely + this syntax with 'extern'. */ +# define _Noreturn [[noreturn]] +# elif (defined __clang__ && __clang_major__ < 16 \ + && defined _GL_WORK_AROUND_LLVM_BUG_59792) + /* Compile with -D_GL_WORK_AROUND_LLVM_BUG_59792 to work around + that rare LLVM bug, though you may get many false-alarm warnings. */ +# define _Noreturn +# elif ((!defined __cplusplus || defined __clang__) \ + && (201112 <= (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) \ + || (!defined __STRICT_ANSI__ \ + && (_GL_GNUC_PREREQ (4, 7) \ + || (defined __apple_build_version__ \ + ? 6000000 <= __apple_build_version__ \ + : 3 < __clang_major__ + (5 <= __clang_minor__)))))) + /* _Noreturn works as-is. */ +# elif _GL_GNUC_PREREQ (2, 8) || defined __clang__ || 0x5110 <= __SUNPRO_C +# define _Noreturn __attribute__ ((__noreturn__)) +# elif 1200 <= (defined _MSC_VER ? _MSC_VER : 0) +# define _Noreturn __declspec (noreturn) +# else +# define _Noreturn +# endif +#endif +]) + AH_VERBATIM([isoc99_inline], +[/* Work around a bug in Apple GCC 4.0.1 build 5465: In C99 mode, it supports + the ISO C 99 semantics of 'extern inline' (unlike the GNU C semantics of + earlier versions), but does not display it by setting __GNUC_STDC_INLINE__. + __APPLE__ && __MACH__ test for Mac OS X. + __APPLE_CC__ tests for the Apple compiler and its version. + __STDC_VERSION__ tests for the C99 mode. */ +#if defined __APPLE__ && defined __MACH__ && __APPLE_CC__ >= 5465 && !defined __cplusplus && __STDC_VERSION__ >= 199901L && !defined __GNUC_STDC_INLINE__ +# define __GNUC_STDC_INLINE__ 1 +#endif]) + AH_VERBATIM([attribute], +[/* Attributes. */ +#if (defined __has_attribute \ + && (!defined __clang_minor__ \ + || (defined __apple_build_version__ \ + ? 6000000 <= __apple_build_version__ \ + : 5 <= __clang_major__))) +# define _GL_HAS_ATTRIBUTE(attr) __has_attribute (__##attr##__) +#else +# define _GL_HAS_ATTRIBUTE(attr) _GL_ATTR_##attr +# define _GL_ATTR_alloc_size _GL_GNUC_PREREQ (4, 3) +# define _GL_ATTR_always_inline _GL_GNUC_PREREQ (3, 2) +# define _GL_ATTR_artificial _GL_GNUC_PREREQ (4, 3) +# define _GL_ATTR_cold _GL_GNUC_PREREQ (4, 3) +# define _GL_ATTR_const _GL_GNUC_PREREQ (2, 95) +# define _GL_ATTR_deprecated _GL_GNUC_PREREQ (3, 1) +# define _GL_ATTR_diagnose_if 0 +# define _GL_ATTR_error _GL_GNUC_PREREQ (4, 3) +# define _GL_ATTR_externally_visible _GL_GNUC_PREREQ (4, 1) +# define _GL_ATTR_fallthrough _GL_GNUC_PREREQ (7, 0) +# define _GL_ATTR_format _GL_GNUC_PREREQ (2, 7) +# define _GL_ATTR_leaf _GL_GNUC_PREREQ (4, 6) +# define _GL_ATTR_malloc _GL_GNUC_PREREQ (3, 0) +# ifdef _ICC +# define _GL_ATTR_may_alias 0 +# else +# define _GL_ATTR_may_alias _GL_GNUC_PREREQ (3, 3) +# endif +# define _GL_ATTR_noinline _GL_GNUC_PREREQ (3, 1) +# define _GL_ATTR_nonnull _GL_GNUC_PREREQ (3, 3) +# define _GL_ATTR_nonstring _GL_GNUC_PREREQ (8, 0) +# define _GL_ATTR_nothrow _GL_GNUC_PREREQ (3, 3) +# define _GL_ATTR_packed _GL_GNUC_PREREQ (2, 7) +# define _GL_ATTR_pure _GL_GNUC_PREREQ (2, 96) +# define _GL_ATTR_returns_nonnull _GL_GNUC_PREREQ (4, 9) +# define _GL_ATTR_sentinel _GL_GNUC_PREREQ (4, 0) +# define _GL_ATTR_unused _GL_GNUC_PREREQ (2, 7) +# define _GL_ATTR_warn_unused_result _GL_GNUC_PREREQ (3, 4) +#endif + +/* Disable GCC -Wpedantic if using __has_c_attribute and this is not C23+. */ +#if (defined __has_c_attribute && _GL_GNUC_PREREQ (4, 6) \ + && (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) <= 201710) +# pragma GCC diagnostic ignored "-Wpedantic" +#endif + +/* Define if, in a function declaration, the attributes in bracket syntax + [[...]] must come before the attributes in __attribute__((...)) syntax. + If this is defined, it is best to avoid the bracket syntax, so that the + various _GL_ATTRIBUTE_* can be cumulated on the same declaration in any + order. */ +#ifdef __cplusplus +# if defined __clang__ +# define _GL_BRACKET_BEFORE_ATTRIBUTE 1 +# endif +#else +# if defined __GNUC__ && !defined __clang__ +# define _GL_BRACKET_BEFORE_ATTRIBUTE 1 +# endif +#endif +]dnl There is no _GL_ATTRIBUTE_ALIGNED; use stdalign's alignas instead. +[ +/* _GL_ATTRIBUTE_ALLOC_SIZE ((N)) declares that the Nth argument of the function + is the size of the returned memory block. + _GL_ATTRIBUTE_ALLOC_SIZE ((M, N)) declares that the Mth argument multiplied + by the Nth argument of the function is the size of the returned memory block. + */ +/* Applies to: function, pointer to function, function types. */ +#ifndef _GL_ATTRIBUTE_ALLOC_SIZE +# if _GL_HAS_ATTRIBUTE (alloc_size) +# define _GL_ATTRIBUTE_ALLOC_SIZE(args) __attribute__ ((__alloc_size__ args)) +# else +# define _GL_ATTRIBUTE_ALLOC_SIZE(args) +# endif +#endif + +/* _GL_ATTRIBUTE_ALWAYS_INLINE tells that the compiler should always inline the + function and report an error if it cannot do so. */ +/* Applies to: function. */ +#ifndef _GL_ATTRIBUTE_ALWAYS_INLINE +# if _GL_HAS_ATTRIBUTE (always_inline) +# define _GL_ATTRIBUTE_ALWAYS_INLINE __attribute__ ((__always_inline__)) +# else +# define _GL_ATTRIBUTE_ALWAYS_INLINE +# endif +#endif + +/* _GL_ATTRIBUTE_ARTIFICIAL declares that the function is not important to show + in stack traces when debugging. The compiler should omit the function from + stack traces. */ +/* Applies to: function. */ +#ifndef _GL_ATTRIBUTE_ARTIFICIAL +# if _GL_HAS_ATTRIBUTE (artificial) +# define _GL_ATTRIBUTE_ARTIFICIAL __attribute__ ((__artificial__)) +# else +# define _GL_ATTRIBUTE_ARTIFICIAL +# endif +#endif + +/* _GL_ATTRIBUTE_COLD declares that the function is rarely executed. */ +/* Applies to: functions. */ +/* Avoid __attribute__ ((cold)) on MinGW; see thread starting at + <https://lists.gnu.org/r/emacs-devel/2019-04/msg01152.html>. + Also, Oracle Studio 12.6 requires 'cold' not '__cold__'. */ +#ifndef _GL_ATTRIBUTE_COLD +# if _GL_HAS_ATTRIBUTE (cold) && !defined __MINGW32__ +# ifndef __SUNPRO_C +# define _GL_ATTRIBUTE_COLD __attribute__ ((__cold__)) +# else +# define _GL_ATTRIBUTE_COLD __attribute__ ((cold)) +# endif +# else +# define _GL_ATTRIBUTE_COLD +# endif +#endif + +/* _GL_ATTRIBUTE_CONST declares that it is OK for a compiler to omit duplicate + calls to the function with the same arguments. + This attribute is safe for a function that neither depends on nor affects + observable state, and always returns exactly once - e.g., does not loop + forever, and does not call longjmp. + (This attribute is stricter than _GL_ATTRIBUTE_PURE.) */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_CONST +# if _GL_HAS_ATTRIBUTE (const) +# define _GL_ATTRIBUTE_CONST __attribute__ ((__const__)) +# else +# define _GL_ATTRIBUTE_CONST +# endif +#endif + +/* _GL_ATTRIBUTE_DEALLOC (F, I) declares that the function returns pointers + that can be freed by passing them as the Ith argument to the + function F. + _GL_ATTRIBUTE_DEALLOC_FREE declares that the function returns pointers that + can be freed via 'free'; it can be used only after declaring 'free'. */ +/* Applies to: functions. Cannot be used on inline functions. */ +#ifndef _GL_ATTRIBUTE_DEALLOC +# if _GL_GNUC_PREREQ (11, 0) +# define _GL_ATTRIBUTE_DEALLOC(f, i) __attribute__ ((__malloc__ (f, i))) +# else +# define _GL_ATTRIBUTE_DEALLOC(f, i) +# endif +#endif +/* If gnulib's <string.h> or <wchar.h> has already defined this macro, continue + to use this earlier definition, since <stdlib.h> may not have been included + yet. */ +#ifndef _GL_ATTRIBUTE_DEALLOC_FREE +# if defined __cplusplus && defined __GNUC__ && !defined __clang__ +/* Work around GCC bug <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108231> */ +# define _GL_ATTRIBUTE_DEALLOC_FREE \ + _GL_ATTRIBUTE_DEALLOC ((void (*) (void *)) free, 1) +# else +# define _GL_ATTRIBUTE_DEALLOC_FREE \ + _GL_ATTRIBUTE_DEALLOC (free, 1) +# endif +#endif + +/* _GL_ATTRIBUTE_DEPRECATED: Declares that an entity is deprecated. + The compiler may warn if the entity is used. */ +/* Applies to: + - function, variable, + - struct, union, struct/union member, + - enumeration, enumeration item, + - typedef, + in C++ also: namespace, class, template specialization. */ +#ifndef _GL_ATTRIBUTE_DEPRECATED +# ifndef _GL_BRACKET_BEFORE_ATTRIBUTE +# ifdef __has_c_attribute +# if __has_c_attribute (__deprecated__) +# define _GL_ATTRIBUTE_DEPRECATED [[__deprecated__]] +# endif +# endif +# endif +# if !defined _GL_ATTRIBUTE_DEPRECATED && _GL_HAS_ATTRIBUTE (deprecated) +# define _GL_ATTRIBUTE_DEPRECATED __attribute__ ((__deprecated__)) +# endif +# ifndef _GL_ATTRIBUTE_DEPRECATED +# define _GL_ATTRIBUTE_DEPRECATED +# endif +#endif + +/* _GL_ATTRIBUTE_ERROR(msg) requests an error if a function is called and + the function call is not optimized away. + _GL_ATTRIBUTE_WARNING(msg) requests a warning if a function is called and + the function call is not optimized away. */ +/* Applies to: functions. */ +#if !(defined _GL_ATTRIBUTE_ERROR && defined _GL_ATTRIBUTE_WARNING) +# if _GL_HAS_ATTRIBUTE (error) +# define _GL_ATTRIBUTE_ERROR(msg) __attribute__ ((__error__ (msg))) +# define _GL_ATTRIBUTE_WARNING(msg) __attribute__ ((__warning__ (msg))) +# elif _GL_HAS_ATTRIBUTE (diagnose_if) +# define _GL_ATTRIBUTE_ERROR(msg) __attribute__ ((__diagnose_if__ (1, msg, "error"))) +# define _GL_ATTRIBUTE_WARNING(msg) __attribute__ ((__diagnose_if__ (1, msg, "warning"))) +# else +# define _GL_ATTRIBUTE_ERROR(msg) +# define _GL_ATTRIBUTE_WARNING(msg) +# endif +#endif + +/* _GL_ATTRIBUTE_EXTERNALLY_VISIBLE declares that the entity should remain + visible to debuggers etc., even with '-fwhole-program'. */ +/* Applies to: functions, variables. */ +#ifndef _GL_ATTRIBUTE_EXTERNALLY_VISIBLE +# if _GL_HAS_ATTRIBUTE (externally_visible) +# define _GL_ATTRIBUTE_EXTERNALLY_VISIBLE __attribute__ ((externally_visible)) +# else +# define _GL_ATTRIBUTE_EXTERNALLY_VISIBLE +# endif +#endif + +/* _GL_ATTRIBUTE_FALLTHROUGH declares that it is not a programming mistake if + the control flow falls through to the immediately following 'case' or + 'default' label. The compiler should not warn in this case. */ +/* Applies to: Empty statement (;), inside a 'switch' statement. */ +/* Always expands to something. */ +#ifndef _GL_ATTRIBUTE_FALLTHROUGH +# ifdef __has_c_attribute +# if __has_c_attribute (__fallthrough__) +# define _GL_ATTRIBUTE_FALLTHROUGH [[__fallthrough__]] +# endif +# endif +# if !defined _GL_ATTRIBUTE_FALLTHROUGH && _GL_HAS_ATTRIBUTE (fallthrough) +# define _GL_ATTRIBUTE_FALLTHROUGH __attribute__ ((__fallthrough__)) +# endif +# ifndef _GL_ATTRIBUTE_FALLTHROUGH +# define _GL_ATTRIBUTE_FALLTHROUGH ((void) 0) +# endif +#endif + +/* _GL_ATTRIBUTE_FORMAT ((ARCHETYPE, STRING-INDEX, FIRST-TO-CHECK)) + declares that the STRING-INDEXth function argument is a format string of + style ARCHETYPE, which is one of: + printf, gnu_printf + scanf, gnu_scanf, + strftime, gnu_strftime, + strfmon, + or the same thing prefixed and suffixed with '__'. + If FIRST-TO-CHECK is not 0, arguments starting at FIRST-TO_CHECK + are suitable for the format string. */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_FORMAT +# if _GL_HAS_ATTRIBUTE (format) +# define _GL_ATTRIBUTE_FORMAT(spec) __attribute__ ((__format__ spec)) +# else +# define _GL_ATTRIBUTE_FORMAT(spec) +# endif +#endif + +/* _GL_ATTRIBUTE_LEAF declares that if the function is called from some other + compilation unit, it executes code from that unit only by return or by + exception handling. This declaration lets the compiler optimize that unit + more aggressively. */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_LEAF +# if _GL_HAS_ATTRIBUTE (leaf) +# define _GL_ATTRIBUTE_LEAF __attribute__ ((__leaf__)) +# else +# define _GL_ATTRIBUTE_LEAF +# endif +#endif + +/* _GL_ATTRIBUTE_MALLOC declares that the function returns a pointer to freshly + allocated memory. */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_MALLOC +# if _GL_HAS_ATTRIBUTE (malloc) +# define _GL_ATTRIBUTE_MALLOC __attribute__ ((__malloc__)) +# else +# define _GL_ATTRIBUTE_MALLOC +# endif +#endif + +/* _GL_ATTRIBUTE_MAY_ALIAS declares that pointers to the type may point to the + same storage as pointers to other types. Thus this declaration disables + strict aliasing optimization. */ +/* Applies to: types. */ +/* Oracle Studio 12.6 mishandles may_alias despite __has_attribute OK. */ +#ifndef _GL_ATTRIBUTE_MAY_ALIAS +# if _GL_HAS_ATTRIBUTE (may_alias) && !defined __SUNPRO_C +# define _GL_ATTRIBUTE_MAY_ALIAS __attribute__ ((__may_alias__)) +# else +# define _GL_ATTRIBUTE_MAY_ALIAS +# endif +#endif + +/* _GL_ATTRIBUTE_MAYBE_UNUSED declares that it is not a programming mistake if + the entity is not used. The compiler should not warn if the entity is not + used. */ +/* Applies to: + - function, variable, + - struct, union, struct/union member, + - enumeration, enumeration item, + - typedef, + in C++ also: class. */ +/* In C++ and C23, this is spelled [[__maybe_unused__]]. + GCC's syntax is __attribute__ ((__unused__)). + clang supports both syntaxes. Except that with clang ≥ 6, < 10, in C++ mode, + __has_c_attribute (__maybe_unused__) yields true but the use of + [[__maybe_unused__]] nevertheless produces a warning. */ +#ifndef _GL_ATTRIBUTE_MAYBE_UNUSED +# ifndef _GL_BRACKET_BEFORE_ATTRIBUTE +# if defined __clang__ && defined __cplusplus +# if !defined __apple_build_version__ && __clang_major__ >= 10 +# define _GL_ATTRIBUTE_MAYBE_UNUSED [[__maybe_unused__]] +# endif +# elif defined __has_c_attribute +# if __has_c_attribute (__maybe_unused__) +# define _GL_ATTRIBUTE_MAYBE_UNUSED [[__maybe_unused__]] +# endif +# endif +# endif +# ifndef _GL_ATTRIBUTE_MAYBE_UNUSED +# define _GL_ATTRIBUTE_MAYBE_UNUSED _GL_ATTRIBUTE_UNUSED +# endif +#endif +/* Alternative spelling of this macro, for convenience and for + compatibility with glibc/include/libc-symbols.h. */ +#define _GL_UNUSED _GL_ATTRIBUTE_MAYBE_UNUSED +/* Earlier spellings of this macro. */ +#define _UNUSED_PARAMETER_ _GL_ATTRIBUTE_MAYBE_UNUSED + +/* _GL_ATTRIBUTE_NODISCARD declares that the caller of the function should not + discard the return value. The compiler may warn if the caller does not use + the return value, unless the caller uses something like ignore_value. */ +/* Applies to: function, enumeration, class. */ +#ifndef _GL_ATTRIBUTE_NODISCARD +# ifndef _GL_BRACKET_BEFORE_ATTRIBUTE +# if defined __clang__ && defined __cplusplus + /* With clang up to 15.0.6 (at least), in C++ mode, [[__nodiscard__]] produces + a warning. + The 1000 below means a yet unknown threshold. When clang++ version X + starts supporting [[__nodiscard__]] without warning about it, you can + replace the 1000 with X. */ +# if __clang_major__ >= 1000 +# define _GL_ATTRIBUTE_NODISCARD [[__nodiscard__]] +# endif +# elif defined __has_c_attribute +# if __has_c_attribute (__nodiscard__) +# define _GL_ATTRIBUTE_NODISCARD [[__nodiscard__]] +# endif +# endif +# endif +# if !defined _GL_ATTRIBUTE_NODISCARD && _GL_HAS_ATTRIBUTE (warn_unused_result) +# define _GL_ATTRIBUTE_NODISCARD __attribute__ ((__warn_unused_result__)) +# endif +# ifndef _GL_ATTRIBUTE_NODISCARD +# define _GL_ATTRIBUTE_NODISCARD +# endif +#endif + +/* _GL_ATTRIBUTE_NOINLINE tells that the compiler should not inline the + function. */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_NOINLINE +# if _GL_HAS_ATTRIBUTE (noinline) +# define _GL_ATTRIBUTE_NOINLINE __attribute__ ((__noinline__)) +# else +# define _GL_ATTRIBUTE_NOINLINE +# endif +#endif + +/* _GL_ATTRIBUTE_NONNULL ((N1, N2,...)) declares that the arguments N1, N2,... + must not be NULL. + _GL_ATTRIBUTE_NONNULL () declares that all pointer arguments must not be + null. */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_NONNULL +# if _GL_HAS_ATTRIBUTE (nonnull) +# define _GL_ATTRIBUTE_NONNULL(args) __attribute__ ((__nonnull__ args)) +# else +# define _GL_ATTRIBUTE_NONNULL(args) +# endif +#endif + +/* _GL_ATTRIBUTE_NONSTRING declares that the contents of a character array is + not meant to be NUL-terminated. */ +/* Applies to: struct/union members and variables that are arrays of element + type '[[un]signed] char'. */ +#ifndef _GL_ATTRIBUTE_NONSTRING +# if _GL_HAS_ATTRIBUTE (nonstring) +# define _GL_ATTRIBUTE_NONSTRING __attribute__ ((__nonstring__)) +# else +# define _GL_ATTRIBUTE_NONSTRING +# endif +#endif + +/* There is no _GL_ATTRIBUTE_NORETURN; use _Noreturn instead. */ + +/* _GL_ATTRIBUTE_NOTHROW declares that the function does not throw exceptions. + */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_NOTHROW +# if _GL_HAS_ATTRIBUTE (nothrow) && !defined __cplusplus +# define _GL_ATTRIBUTE_NOTHROW __attribute__ ((__nothrow__)) +# else +# define _GL_ATTRIBUTE_NOTHROW +# endif +#endif + +/* _GL_ATTRIBUTE_PACKED declares: + For struct members: The member has the smallest possible alignment. + For struct, union, class: All members have the smallest possible alignment, + minimizing the memory required. */ +/* Applies to: struct members, struct, union, + in C++ also: class. */ +#ifndef _GL_ATTRIBUTE_PACKED +# if _GL_HAS_ATTRIBUTE (packed) +# define _GL_ATTRIBUTE_PACKED __attribute__ ((__packed__)) +# else +# define _GL_ATTRIBUTE_PACKED +# endif +#endif + +/* _GL_ATTRIBUTE_PURE declares that It is OK for a compiler to omit duplicate + calls to the function with the same arguments if observable state is not + changed between calls. + This attribute is safe for a function that does not affect + observable state, and always returns exactly once. + (This attribute is looser than _GL_ATTRIBUTE_CONST.) */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_PURE +# if _GL_HAS_ATTRIBUTE (pure) +# define _GL_ATTRIBUTE_PURE __attribute__ ((__pure__)) +# else +# define _GL_ATTRIBUTE_PURE +# endif +#endif + +/* _GL_ATTRIBUTE_RETURNS_NONNULL declares that the function's return value is + a non-NULL pointer. */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_RETURNS_NONNULL +# if _GL_HAS_ATTRIBUTE (returns_nonnull) +# define _GL_ATTRIBUTE_RETURNS_NONNULL __attribute__ ((__returns_nonnull__)) +# else +# define _GL_ATTRIBUTE_RETURNS_NONNULL +# endif +#endif + +/* _GL_ATTRIBUTE_SENTINEL(pos) declares that the variadic function expects a + trailing NULL argument. + _GL_ATTRIBUTE_SENTINEL () - The last argument is NULL (requires C99). + _GL_ATTRIBUTE_SENTINEL ((N)) - The (N+1)st argument from the end is NULL. */ +/* Applies to: functions. */ +#ifndef _GL_ATTRIBUTE_SENTINEL +# if _GL_HAS_ATTRIBUTE (sentinel) +# define _GL_ATTRIBUTE_SENTINEL(pos) __attribute__ ((__sentinel__ pos)) +# else +# define _GL_ATTRIBUTE_SENTINEL(pos) +# endif +#endif + +/* A helper macro. Don't use it directly. */ +#ifndef _GL_ATTRIBUTE_UNUSED +# if _GL_HAS_ATTRIBUTE (unused) +# define _GL_ATTRIBUTE_UNUSED __attribute__ ((__unused__)) +# else +# define _GL_ATTRIBUTE_UNUSED +# endif +#endif + +]dnl There is no _GL_ATTRIBUTE_VISIBILITY; see m4/visibility.m4 instead. +[ +/* _GL_UNUSED_LABEL; declares that it is not a programming mistake if the + immediately preceding label is not used. The compiler should not warn + if the label is not used. */ +/* Applies to: label (both in C and C++). */ +/* Note that g++ < 4.5 does not support the '__attribute__ ((__unused__)) ;' + syntax. But clang does. */ +#ifndef _GL_UNUSED_LABEL +# if !(defined __cplusplus && !_GL_GNUC_PREREQ (4, 5)) || defined __clang__ +# define _GL_UNUSED_LABEL _GL_ATTRIBUTE_UNUSED +# else +# define _GL_UNUSED_LABEL +# endif +#endif +]) + AH_VERBATIM([c_linkage], +[/* In C++, there is the concept of "language linkage", that encompasses + name mangling and function calling conventions. + The following macros start and end a block of "C" linkage. */ +#ifdef __cplusplus +# define _GL_BEGIN_C_LINKAGE extern "C" { +# define _GL_END_C_LINKAGE } +#else +# define _GL_BEGIN_C_LINKAGE +# define _GL_END_C_LINKAGE +#endif +]) + AH_VERBATIM([async_safe], +[/* The _GL_ASYNC_SAFE marker should be attached to functions that are + signal handlers (for signals other than SIGABRT, SIGPIPE) or can be + invoked from such signal handlers. Such functions have some restrictions: + * All functions that it calls should be marked _GL_ASYNC_SAFE as well, + or should be listed as async-signal-safe in POSIX + <https://pubs.opengroup.org/onlinepubs/9699919799/functions/V2_chap02.html#tag_15_04> + section 2.4.3. Note that malloc(), sprintf(), and fwrite(), in + particular, are NOT async-signal-safe. + * All memory locations (variables and struct fields) that these functions + access must be marked 'volatile'. This holds for both read and write + accesses. Otherwise the compiler might optimize away stores to and + reads from such locations that occur in the program, depending on its + data flow analysis. For example, when the program contains a loop + that is intended to inspect a variable set from within a signal handler + while (!signal_occurred) + ; + the compiler is allowed to transform this into an endless loop if the + variable 'signal_occurred' is not declared 'volatile'. + Additionally, recall that: + * A signal handler should not modify errno (except if it is a handler + for a fatal signal and ends by raising the same signal again, thus + provoking the termination of the process). If it invokes a function + that may clobber errno, it needs to save and restore the value of + errno. */ +#define _GL_ASYNC_SAFE +]) + AH_VERBATIM([micro_optimizations], +[/* _GL_CMP (n1, n2) performs a three-valued comparison on n1 vs. n2, where + n1 and n2 are expressions without side effects, that evaluate to real + numbers (excluding NaN). + It returns + 1 if n1 > n2 + 0 if n1 == n2 + -1 if n1 < n2 + The naïve code (n1 > n2 ? 1 : n1 < n2 ? -1 : 0) produces a conditional + jump with nearly all GCC versions up to GCC 10. + This variant (n1 < n2 ? -1 : n1 > n2) produces a conditional with many + GCC versions up to GCC 9. + The better code (n1 > n2) - (n1 < n2) from Hacker's Delight § 2-9 + avoids conditional jumps in all GCC versions >= 3.4. */ +#define _GL_CMP(n1, n2) (((n1) > (n2)) - ((n1) < (n2))) +]) + dnl Hint which direction to take regarding cross-compilation guesses: + dnl When a user installs a program on a platform they are not intimately + dnl familiar with, --enable-cross-guesses=conservative is the appropriate + dnl choice. It implements the "If we don't know, assume the worst" principle. + dnl However, when an operating system developer (on a platform which is not + dnl yet known to gnulib) builds packages for their platform, they want to + dnl expose, not hide, possible platform bugs; in this case, + dnl --enable-cross-guesses=risky is the appropriate choice. + dnl Sets the variables + dnl gl_cross_guess_normal (to be used when 'yes' is good and 'no' is bad), + dnl gl_cross_guess_inverted (to be used when 'no' is good and 'yes' is bad). + AC_ARG_ENABLE([cross-guesses], + [AS_HELP_STRING([[--enable-cross-guesses={conservative|risky}]], + [specify policy for cross-compilation guesses])], + [if test "x$enableval" != xconservative && test "x$enableval" != xrisky; then + AC_MSG_WARN([invalid argument supplied to --enable-cross-guesses]) + enableval=conservative + fi + gl_cross_guesses="$enableval"], + [gl_cross_guesses=conservative]) + if test $gl_cross_guesses = risky; then + gl_cross_guess_normal="guessing yes" + gl_cross_guess_inverted="guessing no" + else + gl_cross_guess_normal="guessing no" + gl_cross_guess_inverted="guessing yes" + fi + dnl Preparation for running test programs: + dnl Tell glibc to write diagnostics from -D_FORTIFY_SOURCE=2 to stderr, not + dnl to /dev/tty, so they can be redirected to log files. Such diagnostics + dnl arise e.g., in the macros gl_PRINTF_DIRECTIVE_N, gl_SNPRINTF_DIRECTIVE_N. + LIBC_FATAL_STDERR_=1 + export LIBC_FATAL_STDERR_ +]) + +# gl_MODULE_INDICATOR_INIT_VARIABLE([variablename]) +# gl_MODULE_INDICATOR_INIT_VARIABLE([variablename], [initialvalue]) +# initializes the shell variable that indicates the presence of the given module +# as a C preprocessor expression. +AC_DEFUN([gl_MODULE_INDICATOR_INIT_VARIABLE], +[ + GL_MODULE_INDICATOR_PREFIX[]_[$1]=m4_if([$2], , [0], [$2]) + AC_SUBST(GL_MODULE_INDICATOR_PREFIX[]_[$1]) +]) + +# gl_MODULE_INDICATOR_CONDITION +# expands to a C preprocessor expression that evaluates to 1 or 0, depending +# whether a gnulib module that has been requested shall be considered present +# or not. +m4_define([gl_MODULE_INDICATOR_CONDITION], [1]) + +# gl_MODULE_INDICATOR_SET_VARIABLE([modulename]) +# sets the shell variable that indicates the presence of the given module to +# a C preprocessor expression that will evaluate to 1. +AC_DEFUN([gl_MODULE_INDICATOR_SET_VARIABLE], +[ + gl_MODULE_INDICATOR_SET_VARIABLE_AUX( + [GL_MODULE_INDICATOR_PREFIX[]_GNULIB_[]m4_translit([[$1]], + [abcdefghijklmnopqrstuvwxyz./-], + [ABCDEFGHIJKLMNOPQRSTUVWXYZ___])], + [gl_MODULE_INDICATOR_CONDITION]) +]) + +# gl_MODULE_INDICATOR_SET_VARIABLE_AUX([variable]) +# modifies the shell variable to include the gl_MODULE_INDICATOR_CONDITION. +# The shell variable's value is a C preprocessor expression that evaluates +# to 0 or 1. +AC_DEFUN([gl_MODULE_INDICATOR_SET_VARIABLE_AUX], +[ + m4_if(m4_defn([gl_MODULE_INDICATOR_CONDITION]), [1], + [ + dnl Simplify the expression VALUE || 1 to 1. + $1=1 + ], + [gl_MODULE_INDICATOR_SET_VARIABLE_AUX_OR([$1], + [gl_MODULE_INDICATOR_CONDITION])]) +]) + +# gl_MODULE_INDICATOR_SET_VARIABLE_AUX_OR([variable], [condition]) +# modifies the shell variable to include the given condition. The shell +# variable's value is a C preprocessor expression that evaluates to 0 or 1. +AC_DEFUN([gl_MODULE_INDICATOR_SET_VARIABLE_AUX_OR], +[ + dnl Simplify the expression 1 || CONDITION to 1. + if test "$[]$1" != 1; then + dnl Simplify the expression 0 || CONDITION to CONDITION. + if test "$[]$1" = 0; then + $1=$2 + else + $1="($[]$1 || $2)" + fi + fi +]) + +# gl_MODULE_INDICATOR([modulename]) +# defines a C macro indicating the presence of the given module +# in a location where it can be used. +# | Value | Value | +# | in lib/ | in tests/ | +# --------------------------------------------+---------+-----------+ +# Module present among main modules: | 1 | 1 | +# --------------------------------------------+---------+-----------+ +# Module present among tests-related modules: | 0 | 1 | +# --------------------------------------------+---------+-----------+ +# Module not present at all: | 0 | 0 | +# --------------------------------------------+---------+-----------+ +AC_DEFUN([gl_MODULE_INDICATOR], +[ + AC_DEFINE_UNQUOTED([GNULIB_]m4_translit([[$1]], + [abcdefghijklmnopqrstuvwxyz./-], + [ABCDEFGHIJKLMNOPQRSTUVWXYZ___]), + [gl_MODULE_INDICATOR_CONDITION], + [Define to a C preprocessor expression that evaluates to 1 or 0, + depending whether the gnulib module $1 shall be considered present.]) +]) + +# gl_MODULE_INDICATOR_FOR_TESTS([modulename]) +# defines a C macro indicating the presence of the given module +# in lib or tests. This is useful to determine whether the module +# should be tested. +# | Value | Value | +# | in lib/ | in tests/ | +# --------------------------------------------+---------+-----------+ +# Module present among main modules: | 1 | 1 | +# --------------------------------------------+---------+-----------+ +# Module present among tests-related modules: | 1 | 1 | +# --------------------------------------------+---------+-----------+ +# Module not present at all: | 0 | 0 | +# --------------------------------------------+---------+-----------+ +AC_DEFUN([gl_MODULE_INDICATOR_FOR_TESTS], +[ + AC_DEFINE([GNULIB_TEST_]m4_translit([[$1]], + [abcdefghijklmnopqrstuvwxyz./-], + [ABCDEFGHIJKLMNOPQRSTUVWXYZ___]), [1], + [Define to 1 when the gnulib module $1 should be tested.]) +]) + +# gl_ASSERT_NO_GNULIB_POSIXCHECK +# asserts that there will never be a need to #define GNULIB_POSIXCHECK. +# and thereby enables an optimization of configure and config.h. +# Used by Emacs. +AC_DEFUN([gl_ASSERT_NO_GNULIB_POSIXCHECK], +[ + dnl Override gl_WARN_ON_USE_PREPARE. + dnl But hide this definition from 'aclocal'. + AC_DEFUN([gl_W][ARN_ON_USE_PREPARE], []) +]) + +# gl_ASSERT_NO_GNULIB_TESTS +# asserts that there will be no gnulib tests in the scope of the configure.ac +# and thereby enables an optimization of config.h. +# Used by Emacs. +AC_DEFUN([gl_ASSERT_NO_GNULIB_TESTS], +[ + dnl Override gl_MODULE_INDICATOR_FOR_TESTS. + AC_DEFUN([gl_MODULE_INDICATOR_FOR_TESTS], []) +]) + +# Test whether <features.h> exists. +# Set HAVE_FEATURES_H. +AC_DEFUN([gl_FEATURES_H], +[ + AC_CHECK_HEADERS_ONCE([features.h]) + if test $ac_cv_header_features_h = yes; then + HAVE_FEATURES_H=1 + else + HAVE_FEATURES_H=0 + fi + AC_SUBST([HAVE_FEATURES_H]) +]) + +# gl_PROG_CC_C99 +# Modifies the value of the shell variable CC in an attempt to make $CC +# understand ISO C99 source code. +AC_DEFUN([gl_PROG_CC_C99], +[ + dnl Just use AC_PROG_CC_C99. + dnl When AC_PROG_CC_C99 and AC_PROG_CC_STDC are used together, the substituted + dnl value of CC will contain the C99 enabling options twice. But this is only + dnl a cosmetic problem. + dnl With Autoconf >= 2.70, use AC_PROG_CC since it implies AC_PROG_CC_C99; + dnl this avoids a "warning: The macro `AC_PROG_CC_C99' is obsolete." + m4_version_prereq([2.70], + [AC_REQUIRE([AC_PROG_CC])], + [AC_REQUIRE([AC_PROG_CC_C99])]) +]) + +# gl_PROG_AR_RANLIB +# Determines the values for AR, ARFLAGS, RANLIB that fit with the compiler. +# The user can set the variables AR, ARFLAGS, RANLIB if he wants to override +# the values. +AC_DEFUN([gl_PROG_AR_RANLIB], +[ + dnl Minix 3 comes with two toolchains: The Amsterdam Compiler Kit compiler + dnl as "cc", and GCC as "gcc". They have different object file formats and + dnl library formats. In particular, the GNU binutils programs ar and ranlib + dnl produce libraries that work only with gcc, not with cc. + AC_REQUIRE([AC_PROG_CC]) + dnl The '][' hides this use from 'aclocal'. + AC_BEFORE([$0], [A][M_PROG_AR]) + AC_CACHE_CHECK([for Minix Amsterdam compiler], [gl_cv_c_amsterdam_compiler], + [ + AC_EGREP_CPP([Amsterdam], + [ +#ifdef __ACK__ +Amsterdam +#endif + ], + [gl_cv_c_amsterdam_compiler=yes], + [gl_cv_c_amsterdam_compiler=no]) + ]) + + dnl Don't compete with AM_PROG_AR's decision about AR/ARFLAGS if we are not + dnl building with __ACK__. + if test $gl_cv_c_amsterdam_compiler = yes; then + if test -z "$AR"; then + AR='cc -c.a' + fi + if test -z "$ARFLAGS"; then + ARFLAGS='-o' + fi + else + dnl AM_PROG_AR was added in automake v1.11.2. AM_PROG_AR does not AC_SUBST + dnl ARFLAGS variable (it is filed into Makefile.in directly by automake + dnl script on-demand, if not specified by ./configure of course). + dnl Don't AC_REQUIRE the AM_PROG_AR otherwise the code for __ACK__ above + dnl will be ignored. Also, pay attention to call AM_PROG_AR in else block + dnl because AM_PROG_AR is written so it could re-set AR variable even for + dnl __ACK__. It may seem like its easier to avoid calling the macro here, + dnl but we need to AC_SUBST both AR/ARFLAGS (thus those must have some good + dnl default value and automake should usually know them). + dnl + dnl The '][' hides this use from 'aclocal'. + m4_ifdef([A][M_PROG_AR], [A][M_PROG_AR], [:]) + fi + + dnl In case the code above has not helped with setting AR/ARFLAGS, use + dnl Automake-documented default values for AR and ARFLAGS, but prefer + dnl ${host}-ar over ar (useful for cross-compiling). + AC_CHECK_TOOL([AR], [ar], [ar]) + if test -z "$ARFLAGS"; then + ARFLAGS='cr' + fi + + AC_SUBST([AR]) + AC_SUBST([ARFLAGS]) + if test -z "$RANLIB"; then + if test $gl_cv_c_amsterdam_compiler = yes; then + RANLIB=':' + else + dnl Use the ranlib program if it is available. + AC_PROG_RANLIB + fi + fi + AC_SUBST([RANLIB]) +]) + +# AC_C_RESTRICT +# This definition is copied from post-2.70 Autoconf and overrides the +# AC_C_RESTRICT macro from autoconf 2.60..2.70. +m4_version_prereq([2.70.1], [], [ +AC_DEFUN([AC_C_RESTRICT], +[AC_CACHE_CHECK([for C/C++ restrict keyword], [ac_cv_c_restrict], + [ac_cv_c_restrict=no + # Put '__restrict__' first, to avoid problems with glibc and non-GCC; see: + # https://lists.gnu.org/archive/html/bug-autoconf/2016-02/msg00006.html + # Put 'restrict' last, because C++ lacks it. + for ac_kw in __restrict__ __restrict _Restrict restrict; do + AC_COMPILE_IFELSE( + [AC_LANG_PROGRAM( + [[typedef int *int_ptr; + int foo (int_ptr $ac_kw ip) { return ip[0]; } + int bar (int [$ac_kw]); /* Catch GCC bug 14050. */ + int bar (int ip[$ac_kw]) { return ip[0]; } + ]], + [[int s[1]; + int *$ac_kw t = s; + t[0] = 0; + return foo (t) + bar (t); + ]])], + [ac_cv_c_restrict=$ac_kw]) + test "$ac_cv_c_restrict" != no && break + done + ]) + AH_VERBATIM([restrict], +[/* Define to the equivalent of the C99 'restrict' keyword, or to + nothing if this is not supported. Do not define if restrict is + supported only directly. */ +#undef restrict +/* Work around a bug in older versions of Sun C++, which did not + #define __restrict__ or support _Restrict or __restrict__ + even though the corresponding Sun C compiler ended up with + "#define restrict _Restrict" or "#define restrict __restrict__" + in the previous line. This workaround can be removed once + we assume Oracle Developer Studio 12.5 (2016) or later. */ +#if defined __SUNPRO_CC && !defined __RESTRICT && !defined __restrict__ +# define _Restrict +# define __restrict__ +#endif]) + case $ac_cv_c_restrict in + restrict) ;; + no) AC_DEFINE([restrict], []) ;; + *) AC_DEFINE_UNQUOTED([restrict], [$ac_cv_c_restrict]) ;; + esac +])# AC_C_RESTRICT +]) + +# gl_BIGENDIAN +# is like AC_C_BIGENDIAN, except that it can be AC_REQUIREd. +# Note that AC_REQUIRE([AC_C_BIGENDIAN]) does not work reliably because some +# macros invoke AC_C_BIGENDIAN with arguments. +AC_DEFUN([gl_BIGENDIAN], +[ + AC_C_BIGENDIAN +]) + +# A temporary file descriptor. +# Must be less than 10, because dash 0.5.8 does not support redirections +# with multi-digit file descriptors. +m4_define([GL_TMP_FD], 9) + +# gl_SILENT(command) +# executes command, but without the normal configure output. +# This is useful when you want to invoke AC_CACHE_CHECK (or AC_CHECK_FUNC etc.) +# inside another AC_CACHE_CHECK. +AC_DEFUN([gl_SILENT], +[ + exec GL_TMP_FD>&AS_MESSAGE_FD AS_MESSAGE_FD>/dev/null + $1 + exec AS_MESSAGE_FD>&GL_TMP_FD GL_TMP_FD>&- +]) + +# gl_CACHE_VAL_SILENT(cache-id, command-to-set-it) +# is like AC_CACHE_VAL(cache-id, command-to-set-it), except that it does not +# output a spurious "(cached)" mark in the midst of other configure output. +# This macro should be used instead of AC_CACHE_VAL when it is not surrounded +# by an AC_MSG_CHECKING/AC_MSG_RESULT pair. +AC_DEFUN([gl_CACHE_VAL_SILENT], +[ + gl_SILENT([ + AC_CACHE_VAL([$1], [$2]) + ]) +]) + +# gl_CONDITIONAL(conditional, condition) +# is like AM_CONDITIONAL(conditional, condition), except that it does not +# produce an error +# configure: error: conditional "..." was never defined. +# Usually this means the macro was only invoked conditionally. +# when only invoked conditionally. Instead, in that case, both the _TRUE +# and the _FALSE case are disabled. +AC_DEFUN([gl_CONDITIONAL], +[ + pushdef([AC_CONFIG_COMMANDS_PRE], [:])dnl + AM_CONDITIONAL([$1], [$2]) + popdef([AC_CONFIG_COMMANDS_PRE])dnl + if test -z "${[$1]_TRUE}" && test -z "${[$1]_FALSE}"; then + [$1]_TRUE='#' + [$1]_FALSE='#' + fi +]) + +# gl_CC_ALLOW_WARNINGS +# sets and substitutes a variable GL_CFLAG_ALLOW_WARNINGS, to a $(CC) option +# that reverts a preceding '-Werror' option, if available. +# This is expected to be '-Wno-error' on gcc, clang (except clang/MSVC), xlclang +# and empty otherwise. +AC_DEFUN([gl_CC_ALLOW_WARNINGS], +[ + AC_REQUIRE([AC_PROG_CC]) + AC_CACHE_CHECK([for C compiler option to allow warnings], + [gl_cv_cc_wallow], + [rm -f conftest* + echo 'int dummy;' > conftest.c + AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS -c conftest.c 2>conftest1.err]) >/dev/null + AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS -Wno-error -c conftest.c 2>conftest2.err]) >/dev/null + dnl Test the number of error output lines, because AIX xlc accepts the + dnl option '-Wno-error', just to produce a warning + dnl "Option -Wno-error was incorrectly specified. The option will be ignored." + dnl afterwards. + if test $? = 0 && test `wc -l < conftest1.err` = `wc -l < conftest2.err`; then + gl_cv_cc_wallow='-Wno-error' + else + gl_cv_cc_wallow=none + fi + rm -f conftest* + ]) + case "$gl_cv_cc_wallow" in + none) GL_CFLAG_ALLOW_WARNINGS='' ;; + *) GL_CFLAG_ALLOW_WARNINGS="$gl_cv_cc_wallow" ;; + esac + AC_SUBST([GL_CFLAG_ALLOW_WARNINGS]) +]) + +# gl_CXX_ALLOW_WARNINGS +# sets and substitutes a variable GL_CXXFLAG_ALLOW_WARNINGS, to a $(CC) option +# that reverts a preceding '-Werror' option, if available. +AC_DEFUN([gl_CXX_ALLOW_WARNINGS], +[ + dnl Requires AC_PROG_CXX or gl_PROG_ANSI_CXX. + if test -n "$CXX" && test "$CXX" != no; then + AC_CACHE_CHECK([for C++ compiler option to allow warnings], + [gl_cv_cxx_wallow], + [rm -f conftest* + echo 'int dummy;' > conftest.cc + AC_TRY_COMMAND([${CXX-c++} $CXXFLAGS $CPPFLAGS -c conftest.cc 2>conftest1.err]) >/dev/null + AC_TRY_COMMAND([${CXX-c++} $CXXFLAGS $CPPFLAGS -Wno-error -c conftest.cc 2>conftest2.err]) >/dev/null + dnl Test the number of error output lines, because AIX xlC accepts the + dnl option '-Wno-error', just to produce a warning + dnl "Option -Wno-error was incorrectly specified. The option will be ignored." + dnl afterwards. + if test $? = 0 && test `wc -l < conftest1.err` = `wc -l < conftest2.err`; then + gl_cv_cxx_wallow='-Wno-error' + else + gl_cv_cxx_wallow=none + fi + rm -f conftest* + ]) + case "$gl_cv_cxx_wallow" in + none) GL_CXXFLAG_ALLOW_WARNINGS='' ;; + *) GL_CXXFLAG_ALLOW_WARNINGS="$gl_cv_cxx_wallow" ;; + esac + else + GL_CXXFLAG_ALLOW_WARNINGS='' + fi + AC_SUBST([GL_CXXFLAG_ALLOW_WARNINGS]) +]) + +# gl_CC_GNULIB_WARNINGS +# sets and substitutes a variable GL_CFLAG_GNULIB_WARNINGS, to a $(CC) option +# set that enables or disables warnings as suitable for the Gnulib coding style. +AC_DEFUN([gl_CC_GNULIB_WARNINGS], +[ + AC_REQUIRE([gl_CC_ALLOW_WARNINGS]) + dnl Assume that the compiler supports -Wno-* options only if it also supports + dnl -Wno-error. + GL_CFLAG_GNULIB_WARNINGS='' + if test -n "$GL_CFLAG_ALLOW_WARNINGS"; then + dnl Enable these warning options: + dnl + dnl GCC clang + dnl -Wno-cast-qual >= 3 >= 3.9 + dnl -Wno-conversion >= 3 >= 3.9 + dnl -Wno-float-conversion >= 4.9 >= 3.9 + dnl -Wno-float-equal >= 3 >= 3.9 + dnl -Wimplicit-fallthrough >= 7 >= 3.9 + dnl -Wno-pedantic >= 4.8 >= 3.9 + dnl -Wno-sign-compare >= 3 >= 3.9 + dnl -Wno-sign-conversion >= 4.3 >= 3.9 + dnl -Wno-type-limits >= 4.3 >= 3.9 + dnl -Wno-undef >= 3 >= 3.9 + dnl -Wno-unsuffixed-float-constants >= 4.5 + dnl -Wno-unused-function >= 3 >= 3.9 + dnl -Wno-unused-parameter >= 3 >= 3.9 + dnl + cat > conftest.c <<\EOF + #if __GNUC__ >= 3 || (__clang_major__ + (__clang_minor__ >= 9) > 3) + -Wno-cast-qual + -Wno-conversion + -Wno-float-equal + -Wno-sign-compare + -Wno-undef + -Wno-unused-function + -Wno-unused-parameter + #endif + #if __GNUC__ + (__GNUC_MINOR__ >= 9) > 4 || (__clang_major__ + (__clang_minor__ >= 9) > 3) + -Wno-float-conversion + #endif + #if __GNUC__ >= 7 || (__clang_major__ + (__clang_minor__ >= 9) > 3) + -Wimplicit-fallthrough + #endif + #if __GNUC__ + (__GNUC_MINOR__ >= 8) > 4 || (__clang_major__ + (__clang_minor__ >= 9) > 3) + -Wno-pedantic + #endif + #if __GNUC__ + (__GNUC_MINOR__ >= 3) > 4 || (__clang_major__ + (__clang_minor__ >= 9) > 3) + -Wno-sign-conversion + -Wno-type-limits + #endif + #if __GNUC__ + (__GNUC_MINOR__ >= 5) > 4 + -Wno-unsuffixed-float-constants + #endif +EOF + gl_command="$CC $CFLAGS $CPPFLAGS -E conftest.c > conftest.out" + if AC_TRY_EVAL([gl_command]); then + gl_options=`grep -v '#' conftest.out` + for word in $gl_options; do + GL_CFLAG_GNULIB_WARNINGS="$GL_CFLAG_GNULIB_WARNINGS $word" + done + fi + rm -f conftest.c conftest.out + fi + AC_SUBST([GL_CFLAG_GNULIB_WARNINGS]) +]) + +dnl gl_CONDITIONAL_HEADER([foo.h]) +dnl takes a shell variable GL_GENERATE_FOO_H (with value true or false) as input +dnl and produces +dnl - an AC_SUBSTed variable FOO_H that is either a file name or empty, based +dnl on whether GL_GENERATE_FOO_H is true or false, +dnl - an Automake conditional GL_GENERATE_FOO_H that evaluates to the value of +dnl the shell variable GL_GENERATE_FOO_H. +AC_DEFUN([gl_CONDITIONAL_HEADER], +[ + m4_pushdef([gl_header_name], AS_TR_SH(m4_toupper($1))) + m4_pushdef([gl_generate_var], [GL_GENERATE_]AS_TR_SH(m4_toupper($1))) + m4_pushdef([gl_generate_cond], [GL_GENERATE_]AS_TR_SH(m4_toupper($1))) + case "$gl_generate_var" in + false) gl_header_name='' ;; + true) + dnl It is OK to use a .h file in lib/ from within tests/, but not vice + dnl versa. + if test -z "$gl_header_name"; then + gl_header_name="${gl_source_base_prefix}$1" + fi + ;; + *) echo "*** gl_generate_var is not set correctly" 1>&2; exit 1 ;; + esac + AC_SUBST(gl_header_name) + gl_CONDITIONAL(gl_generate_cond, [$gl_generate_var]) + m4_popdef([gl_generate_cond]) + m4_popdef([gl_generate_var]) + m4_popdef([gl_header_name]) +]) + +dnl Preparations for gl_CHECK_FUNCS_MACOS. +AC_DEFUN([gl_PREPARE_CHECK_FUNCS_MACOS], +[ + AC_REQUIRE([AC_CANONICAL_HOST]) + AC_REQUIRE([gl_COMPILER_CLANG]) + AC_CACHE_CHECK([for compiler option needed when checking for future declarations], + [gl_cv_compiler_check_future_option], + [case "$host_os" in + dnl This is only needed on macOS. + darwin*) + if test $gl_cv_compiler_clang = yes; then + dnl Test whether the compiler supports the option + dnl '-Werror=unguarded-availability-new'. + save_ac_compile="$ac_compile" + ac_compile="$ac_compile -Werror=unguarded-availability-new" + AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]],[[]])], + [gl_cv_compiler_check_future_option='-Werror=unguarded-availability-new'], + [gl_cv_compiler_check_future_option=none]) + ac_compile="$save_ac_compile" + else + gl_cv_compiler_check_future_option=none + fi + ;; + *) gl_cv_compiler_check_future_option=none ;; + esac + ]) +]) + +dnl Pieces of the expansion of +dnl gl_CHECK_FUNCS_ANDROID +dnl gl_CHECK_FUNCS_MACOS +dnl gl_CHECK_FUNCS_ANDROID_MACOS + +AC_DEFUN([gl_CHECK_FUNCS_DEFAULT_CASE], +[ + *) + AC_CHECK_FUNC([$1]) + [gl_cv_onwards_func_][$1]=$[ac_cv_func_][$1] + ;; +]) + +AC_DEFUN([gl_CHECK_FUNCS_CASE_FOR_ANDROID], +[ + linux*-android*) + AC_CHECK_DECL([$1], , , [$2]) + if test $[ac_cv_have_decl_][$1] = yes; then + AC_CHECK_FUNC([[$1]]) + if test $[ac_cv_func_][$1] = yes; then + [gl_cv_onwards_func_][$1]=yes + else + dnl The function is declared but does not exist. This should not + dnl happen normally. But anyway, we know that a future version + dnl of Android will have the function. + [gl_cv_onwards_func_][$1]='future OS version' + fi + else + [gl_cv_onwards_func_][$1]='future OS version' + fi + ;; +]) + +AC_DEFUN([gl_CHECK_FUNCS_CASE_FOR_MACOS], +[ + darwin*) + if test "x$gl_cv_compiler_check_future_option" != "xnone"; then + dnl Use a compile test, not a link test. + save_ac_compile="$ac_compile" + ac_compile="$ac_compile $gl_cv_compiler_check_future_option" + save_ac_compile_for_check_decl="$ac_compile_for_check_decl" + ac_compile_for_check_decl="$ac_compile_for_check_decl $gl_cv_compiler_check_future_option" + unset [ac_cv_have_decl_][$1] + AC_CHECK_DECL([$1], , , [$2]) + ac_compile="$save_ac_compile" + ac_compile_for_check_decl="$save_ac_compile_for_check_decl" + [ac_cv_func_][$1]="$[ac_cv_have_decl_][$1]" + if test $[ac_cv_func_][$1] = yes; then + [gl_cv_onwards_func_][$1]=yes + else + unset [ac_cv_have_decl_][$1] + AC_CHECK_DECL([$1], , , [$2]) + if test $[ac_cv_have_decl_][$1] = yes; then + [gl_cv_onwards_func_][$1]='future OS version' + else + [gl_cv_onwards_func_][$1]=no + fi + fi + else + AC_CHECK_FUNC([$1]) + [gl_cv_onwards_func_][$1]=$[ac_cv_func_][$1] + fi + ;; +]) + +AC_DEFUN([gl_CHECK_FUNCS_SET_RESULTS], +[ + case "$[gl_cv_onwards_func_][$1]" in + future*) [ac_cv_func_][$1]=no ;; + *) [ac_cv_func_][$1]=$[gl_cv_onwards_func_][$1] ;; + esac + if test $[ac_cv_func_][$1] = yes; then + AC_DEFINE([HAVE_]m4_translit([[$1]], + [abcdefghijklmnopqrstuvwxyz], + [ABCDEFGHIJKLMNOPQRSTUVWXYZ]), + [1], [Define to 1 if you have the `$1' function.]) + fi +]) + +dnl gl_CHECK_FUNCS_ANDROID([func], [[#include <foo.h>]]) +dnl is like AC_CHECK_FUNCS([func]), taking into account a portability problem +dnl on Android. +dnl +dnl When code is compiled on Android, it is in the context of a certain +dnl "Android API level", which indicates the minimum version of Android on +dnl which the app can be installed. In other words, you don't compile for a +dnl specific version of Android. You compile for all versions of Android, +dnl onwards from the given API level. +dnl Thus, the question "does the OS have the function func" has three possible +dnl answers: +dnl - yes, in all versions starting from the given API level, +dnl - no, in no version, +dnl - not in the given API level, but in a later version of Android. +dnl +dnl In detail, this works as follows: +dnl If func was added to Android API level, say, 28, then the libc.so has the +dnl symbol func always, whereas the header file <foo.h> declares func +dnl conditionally: +dnl #if __ANDROID_API__ >= 28 +dnl ... func (...) __INTRODUCED_IN(28); +dnl #endif +dnl Thus, when compiling with "clang -target armv7a-unknown-linux-android28", +dnl the function func is declared and exists in libc. +dnl Whereas when compiling with "clang -target armv7a-unknown-linux-android27", +dnl the function func is not declared but exists in libc. +dnl +dnl This macro sets two variables: +dnl - gl_cv_onwards_func_<func> to yes / no / "future OS version" +dnl - ac_cv_func_<func> to yes / no / no +dnl The first variable allows to distinguish all three cases. +dnl The second variable is set, so that an invocation +dnl gl_CHECK_FUNCS_ANDROID([func], [[#include <foo.h>]]) +dnl can be used as a drop-in replacement for +dnl AC_CHECK_FUNCS([func]). +AC_DEFUN([gl_CHECK_FUNCS_ANDROID], +[ + AC_REQUIRE([AC_CANONICAL_HOST]) + AC_CACHE_CHECK([for [$1]], + [[gl_cv_onwards_func_][$1]], + [gl_SILENT([ + case "$host_os" in + gl_CHECK_FUNCS_CASE_FOR_ANDROID([$1], [$2]) + gl_CHECK_FUNCS_DEFAULT_CASE([$1]) + esac + ]) + ]) + gl_CHECK_FUNCS_SET_RESULTS([$1]) +]) + +dnl gl_CHECK_FUNCS_MACOS([func], [[#include <foo.h>]]) +dnl is like AC_CHECK_FUNCS([func]), taking into account a portability problem +dnl on macOS. +dnl +dnl When code is compiled on macOS, it is in the context of a certain minimum +dnl macOS version, that can be set through the option '-mmacosx-version-min='. +dnl In other words, you don't compile for a specific version of macOS. You +dnl compile for all versions of macOS, onwards from the given version. +dnl Thus, the question "does the OS have the function func" has three possible +dnl answers: +dnl - yes, in all versions starting from the given version, +dnl - no, in no version, +dnl - not in the given version, but in a later version of macOS. +dnl +dnl In detail, this works as follows: +dnl If func was added to, say, macOS version 13, then the libc has the +dnl symbol func always, whereas the header file <foo.h> declares func +dnl conditionally with a special availability attribute: +dnl ... func (...) __attribute__((availability(macos,introduced=13.0))); +dnl Thus, when compiling with "clang mmacosx-version-min=13", there is no +dnl warning about the use of func, and the resulting binary +dnl - runs fine on macOS 13, +dnl - aborts with a dyld "Symbol not found" message on macOS 12. +dnl Whereas, when compiling with "clang mmacosx-version-min=12", there is a +dnl warning: 'func' is only available on macOS 13.0 or newer +dnl [-Wunguarded-availability-new], +dnl and the resulting binary +dnl - runs fine on macOS 13, +dnl - crashes with a SIGSEGV (signal 11) on macOS 12. +dnl +dnl This macro sets two variables: +dnl - gl_cv_onwards_func_<func> to yes / no / "future OS version" +dnl - ac_cv_func_<func> to yes / no / no +dnl The first variable allows to distinguish all three cases. +dnl The second variable is set, so that an invocation +dnl gl_CHECK_FUNCS_MACOS([func], [[#include <foo.h>]]) +dnl can be used as a drop-in replacement for +dnl AC_CHECK_FUNCS([func]). +AC_DEFUN([gl_CHECK_FUNCS_MACOS], +[ + AC_REQUIRE([AC_CANONICAL_HOST]) + AC_REQUIRE([gl_PREPARE_CHECK_FUNCS_MACOS]) + AC_CACHE_CHECK([for [$1]], + [[gl_cv_onwards_func_][$1]], + [gl_SILENT([ + case "$host_os" in + gl_CHECK_FUNCS_CASE_FOR_MACOS([$1], [$2]) + gl_CHECK_FUNCS_DEFAULT_CASE([$1]) + esac + ]) + ]) + gl_CHECK_FUNCS_SET_RESULTS([$1]) +]) + +dnl gl_CHECK_FUNCS_ANDROID_MACOS([func], [[#include <foo.h>]]) +dnl is like AC_CHECK_FUNCS([func]), taking into account a portability problem +dnl on Android and on macOS. +dnl It is the combination of gl_CHECK_FUNCS_ANDROID and gl_CHECK_FUNCS_MACOS. +AC_DEFUN([gl_CHECK_FUNCS_ANDROID_MACOS], +[ + AC_REQUIRE([AC_CANONICAL_HOST]) + AC_REQUIRE([gl_PREPARE_CHECK_FUNCS_MACOS]) + AC_CACHE_CHECK([for [$1]], + [[gl_cv_onwards_func_][$1]], + [gl_SILENT([ + case "$host_os" in + gl_CHECK_FUNCS_CASE_FOR_ANDROID([$1], [$2]) + gl_CHECK_FUNCS_CASE_FOR_MACOS([$1], [$2]) + gl_CHECK_FUNCS_DEFAULT_CASE([$1]) + esac + ]) + ]) + gl_CHECK_FUNCS_SET_RESULTS([$1]) +]) + +dnl Expands to some code for use in .c programs that, on native Windows, defines +dnl the Microsoft deprecated alias function names to the underscore-prefixed +dnl actual function names. With this macro, these function names are available +dnl without linking with '-loldnames' and without generating warnings. +dnl Usage: Use it after all system header files are included. +dnl #include <...> +dnl #include <...> +dnl ]GL_MDA_DEFINES[ +dnl ... +AC_DEFUN([GL_MDA_DEFINES],[ +AC_REQUIRE([_GL_MDA_DEFINES]) +[$gl_mda_defines] +]) +AC_DEFUN([_GL_MDA_DEFINES], +[gl_mda_defines=' +#if defined _WIN32 && !defined __CYGWIN__ +#define access _access +#define chdir _chdir +#define chmod _chmod +#define close _close +#define creat _creat +#define dup _dup +#define dup2 _dup2 +#define ecvt _ecvt +#define execl _execl +#define execle _execle +#define execlp _execlp +#define execv _execv +#define execve _execve +#define execvp _execvp +#define execvpe _execvpe +#define fcloseall _fcloseall +#define fcvt _fcvt +#define fdopen _fdopen +#define fileno _fileno +#define gcvt _gcvt +#define getcwd _getcwd +#define getpid _getpid +#define getw _getw +#define isatty _isatty +#define j0 _j0 +#define j1 _j1 +#define jn _jn +#define lfind _lfind +#define lsearch _lsearch +#define lseek _lseek +#define memccpy _memccpy +#define mkdir _mkdir +#define mktemp _mktemp +#define open _open +#define putenv _putenv +#define putw _putw +#define read _read +#define rmdir _rmdir +#define strdup _strdup +#define swab _swab +#define tempnam _tempnam +#define tzset _tzset +#define umask _umask +#define unlink _unlink +#define utime _utime +#define wcsdup _wcsdup +#define write _write +#define y0 _y0 +#define y1 _y1 +#define yn _yn +#endif +' +]) |