From 86d78ef50e0195f8181f2b0bd9540f4ddfb73480 Mon Sep 17 00:00:00 2001 From: Andres Freund Date: Thu, 16 Aug 2018 01:32:05 -0700 Subject: [PATCH] Try to enable C99 in configure, but do not rely on it (yet). Based on recent discussion it seems possible that we might start to rely on more of C99. A prerequisite for that is enabling support for that on used compilers. Let's see on which buildfarm members autoconf's AC_PROG_CC_C99() is sufficient to do so. There's probably at least one member where the compiler is too old, but that'd probably be OK. If we go for this permanently we'd likely want to clean out / up a few other configure tests. Note this does not touch the msvc build infrastructure, which'd need separate treatment. Discussion: https://postgr.es/m/20180815222401.kxsupl5zie2jgi4x@alap3.anarazel.de --- configure | 177 +++++++++++++++++++++++++++++++++++++++++++++++++++ configure.in | 1 + 2 files changed, 178 insertions(+) diff --git a/configure b/configure index 067fc43e4e..1aaca9ab5c 100755 --- a/configure +++ b/configure @@ -4425,6 +4425,183 @@ ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5' ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5' ac_compiler_gnu=$ac_cv_c_compiler_gnu + { $as_echo "$as_me:${as_lineno-$LINENO}: checking for $CC option to accept ISO C99" >&5 +$as_echo_n "checking for $CC option to accept ISO C99... " >&6; } +if ${ac_cv_prog_cc_c99+:} false; then : + $as_echo_n "(cached) " >&6 +else + ac_cv_prog_cc_c99=no +ac_save_CC=$CC +cat confdefs.h - <<_ACEOF >conftest.$ac_ext +/* end confdefs.h. */ +#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); +} + +int +main () +{ + + // 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); + + ; + return 0; +} +_ACEOF +for ac_arg in '' -std=gnu99 -std=c99 -c99 -AC99 -D_STDC_C99= -qlanglvl=extc99 +do + CC="$ac_save_CC $ac_arg" + if ac_fn_c_try_compile "$LINENO"; then : + ac_cv_prog_cc_c99=$ac_arg +fi +rm -f core conftest.err conftest.$ac_objext + test "x$ac_cv_prog_cc_c99" != "xno" && break +done +rm -f conftest.$ac_ext +CC=$ac_save_CC + +fi +# AC_CACHE_VAL +case "x$ac_cv_prog_cc_c99" in + x) + { $as_echo "$as_me:${as_lineno-$LINENO}: result: none needed" >&5 +$as_echo "none needed" >&6; } ;; + xno) + { $as_echo "$as_me:${as_lineno-$LINENO}: result: unsupported" >&5 +$as_echo "unsupported" >&6; } ;; + *) + CC="$CC $ac_cv_prog_cc_c99" + { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_prog_cc_c99" >&5 +$as_echo "$ac_cv_prog_cc_c99" >&6; } ;; +esac +if test "x$ac_cv_prog_cc_c99" != xno; then : + +fi + + ac_ext=cpp ac_cpp='$CXXCPP $CPPFLAGS' ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5' diff --git a/configure.in b/configure.in index 49257e5301..24372b6cee 100644 --- a/configure.in +++ b/configure.in @@ -358,6 +358,7 @@ case $template in esac AC_PROG_CC([$pgac_cc_list]) +AC_PROG_CC_C99() AC_PROG_CXX([$pgac_cxx_list]) # Check if it's Intel's compiler, which (usually) pretends to be gcc,