From a0a70329033f3f88de500b8f098e989247dd8f91 Mon Sep 17 00:00:00 2001 From: Dustin Sallings Date: Mon, 15 Feb 2010 15:53:52 -0800 Subject: Backporting AC_PROG_CC_C99 macro for redhat. RedHat 5.4 (and CentOS) ship with 2.59 which doesn't have the AC_PROG_CC_C99 macro necessary for detecting C99 flags for the compiler. --- m4/c99-backport.m4 | 188 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 188 insertions(+) create mode 100644 m4/c99-backport.m4 (limited to 'm4') diff --git a/m4/c99-backport.m4 b/m4/c99-backport.m4 new file mode 100644 index 0000000..0812584 --- /dev/null +++ b/m4/c99-backport.m4 @@ -0,0 +1,188 @@ +# AC_PROG_CC_C99 ([ACTION-IF-AVAILABLE], [ACTION-IF-UNAVAILABLE]) +# ---------------------------------------------------------------- +# If the C compiler is not in ISO C99 mode by default, try to add an +# option to output variable CC to make it so. This macro tries +# various options that select ISO C99 on some system or another. It +# considers the compiler to be in ISO C99 mode if it handles _Bool, +# // comments, flexible array members, inline, long long int, mixed +# code and declarations, named initialization of structs, restrict, +# va_copy, varargs macros, variable declarations in for loops and +# variable length arrays. +AC_DEFUN([AC_PROG_CC_C99], +[AC_C_STD_TRY([c99], +[[#include +#include +#include +#include +#include + +// Check varargs macros. These examples are taken from C99 6.10.3.5. +#define debug(...) fprintf (stderr, __VA_ARGS__) +#define showlist(...) puts (#__VA_ARGS__) +#define report(test,...) ((test) ? puts (#test) : printf (__VA_ARGS__)) +static void +test_varargs_macros (void) +{ + int x = 1234; + int y = 5678; + debug ("Flag"); + debug ("X = %d\n", x); + showlist (The first, second, and third items.); + report (x>y, "x is %d but y is %d", x, y); +} + +// Check long long types. +#define BIG64 18446744073709551615ull +#define BIG32 4294967295ul +#define BIG_OK (BIG64 / BIG32 == 4294967297ull && BIG64 % BIG32 == 0) +#if !BIG_OK + your preprocessor is broken; +#endif +#if BIG_OK +#else + your preprocessor is broken; +#endif +static long long int bignum = -9223372036854775807LL; +static unsigned long long int ubignum = BIG64; + +struct incomplete_array +{ + int datasize; + double data[]; +}; + +struct named_init { + int number; + const wchar_t *name; + double average; +}; + +typedef const char *ccp; + +static inline int +test_restrict (ccp restrict text) +{ + // See if C++-style comments work. + // Iterate through items via the restricted pointer. + // Also check for declarations in for loops. + for (unsigned int i = 0; *(text+i) != '\0'; ++i) + continue; + return 0; +} + +// Check varargs and va_copy. +static void +test_varargs (const char *format, ...) +{ + va_list args; + va_start (args, format); + va_list args_copy; + va_copy (args_copy, args); + + const char *str; + int number; + float fnumber; + + while (*format) + { + switch (*format++) + { + case 's': // string + str = va_arg (args_copy, const char *); + break; + case 'd': // int + number = va_arg (args_copy, int); + break; + case 'f': // float + fnumber = va_arg (args_copy, double); + break; + default: + break; + } + } + va_end (args_copy); + va_end (args); +} +]], +[[ + // Check bool. + _Bool success = false; + + // Check restrict. + if (test_restrict ("String literal") == 0) + success = true; + char *restrict newvar = "Another string"; + + // Check varargs. + test_varargs ("s, d' f .", "string", 65, 34.234); + test_varargs_macros (); + + // Check flexible array members. + struct incomplete_array *ia = + malloc (sizeof (struct incomplete_array) + (sizeof (double) * 10)); + ia->datasize = 10; + for (int i = 0; i < ia->datasize; ++i) + ia->data[i] = i * 1.234; + + // Check named initializers. + struct named_init ni = { + .number = 34, + .name = L"Test wide string", + .average = 543.34343, + }; + + ni.number = 58; + + int dynamic_array[ni.number]; + dynamic_array[ni.number - 1] = 543; + + // work around unused variable warnings + return (!success || bignum == 0LL || ubignum == 0uLL || newvar[0] == 'x' + || dynamic_array[ni.number - 1] != 543); +]], +dnl Try +dnl GCC -std=gnu99 (unused restrictive modes: -std=c99 -std=iso9899:1999) +dnl AIX -qlanglvl=extc99 (unused restrictive mode: -qlanglvl=stdc99) +dnl Intel ICC -c99 +dnl IRIX -c99 +dnl Solaris (unused because it causes the compiler to assume C99 semantics for +dnl library functions, and this is invalid before Solaris 10: -xc99) +dnl Tru64 -c99 +dnl with extended modes being tried first. +[[-std=gnu99 -c99 -qlanglvl=extc99]], [$1], [$2])[]dnl +])# AC_PROG_CC_C99 + +# AC_C_STD_TRY(STANDARD, TEST-PROLOGUE, TEST-BODY, OPTION-LIST, +# ACTION-IF-AVAILABLE, ACTION-IF-UNAVAILABLE) +# -------------------------------------------------------------- +# Check whether the C compiler accepts features of STANDARD (e.g `c89', `c99') +# by trying to compile a program of TEST-PROLOGUE and TEST-BODY. If this fails, +# try again with each compiler option in the space-separated OPTION-LIST; if one +# helps, append it to CC. If eventually successful, run ACTION-IF-AVAILABLE, +# else ACTION-IF-UNAVAILABLE. +AC_DEFUN([AC_C_STD_TRY], +[AC_MSG_CHECKING([for $CC option to accept ISO ]m4_translit($1, [c], [C])) +AC_CACHE_VAL(ac_cv_prog_cc_$1, +[ac_cv_prog_cc_$1=no +ac_save_CC=$CC +AC_LANG_CONFTEST([AC_LANG_PROGRAM([$2], [$3])]) +for ac_arg in '' $4 +do + CC="$ac_save_CC $ac_arg" + _AC_COMPILE_IFELSE([], [ac_cv_prog_cc_$1=$ac_arg]) + test "x$ac_cv_prog_cc_$1" != "xno" && break +done +rm -f conftest.$ac_ext +CC=$ac_save_CC +])# AC_CACHE_VAL +case "x$ac_cv_prog_cc_$1" in + x) + AC_MSG_RESULT([none needed]) ;; + xno) + AC_MSG_RESULT([unsupported]) ;; + *) + CC="$CC $ac_cv_prog_cc_$1" + AC_MSG_RESULT([$ac_cv_prog_cc_$1]) ;; +esac +AS_IF([test "x$ac_cv_prog_cc_$1" != xno], [$5], [$6]) +])# AC_C_STD_TRY -- cgit v1.2.1