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| author | Simon McVittie <smcv@collabora.com> | 2018-11-15 17:40:33 +0000 |
|---|---|---|
| committer | Simon McVittie <smcv@collabora.com> | 2018-11-19 11:27:25 +0000 |
| commit | 6278951f6deb4a2a3b2177dfaaa64bd64fa13701 (patch) | |
| tree | 6257fe7384ffce9e9811cdc79bcb7dc61d486d65 /configure.ac | |
| parent | c018e0b1b28107cac6d243295b7afa8939fdbdcd (diff) | |
| download | dbus-6278951f6deb4a2a3b2177dfaaa64bd64fa13701.tar.gz | |
Don't check how to copy a va_list if we already have va_copy()
If we already have ISO C va_copy() or its non-standard counterpart
__va_copy(), then there's no need to do an AC_RUN_IFELSE or its
CMake equivalent to detect whether "args2 = args1" or "*args2 = *args1"
works. AC_RUN_IFELSE is problematic during cross-compilation, where the
program cannot be run (you have to know in advance that the test program
will be run and what its result will be), so we want to avoid it whenever
possible.
Signed-off-by: Simon McVittie <smcv@collabora.com>
Diffstat (limited to 'configure.ac')
| -rw-r--r-- | configure.ac | 70 |
1 files changed, 34 insertions, 36 deletions
diff --git a/configure.ac b/configure.ac index 89337836..fa542290 100644 --- a/configure.ac +++ b/configure.ac @@ -563,42 +563,40 @@ else if test "x$dbus_cv___va_copy" = "xyes"; then fi fi -if test -n "$dbus_va_copy_func"; then - AC_DEFINE_UNQUOTED(DBUS_VA_COPY,$dbus_va_copy_func,[A 'va_copy' style function]) -fi - -AC_LANG_PUSH(C) -AC_CACHE_CHECK([whether va_lists can be copied by value], - dbus_cv_va_val_copy, - [AC_RUN_IFELSE([AC_LANG_PROGRAM( -[[ - #include <stdarg.h> - #include <stdlib.h> -]], -[[ - static void f (int i, ...) { - va_list args1, args2; - va_start (args1, i); - args2 = args1; - if (va_arg (args2, int) != 42 || va_arg (args1, int) != 42) - exit (1); - va_end (args1); va_end (args2); - } - int main() { - f (0, 42); - return 0; - } -]])], - [dbus_cv_va_val_copy=yes], - [dbus_cv_va_val_copy=no], - [dbus_cv_va_val_copy=yes]) -]) -AC_LANG_POP(C) - -if test "x$dbus_cv_va_val_copy" = "xno"; then - AC_DEFINE(DBUS_VA_COPY_AS_ARRAY,1, ['va_lists' cannot be copies as values]) -fi - +AS_IF([test -n "$dbus_va_copy_func"], + [AC_DEFINE_UNQUOTED([DBUS_VA_COPY], [$dbus_va_copy_func], [A 'va_copy' style function])], + [ + AC_LANG_PUSH([C]) + AC_CACHE_CHECK([whether va_lists can be copied by value], + [dbus_cv_va_val_copy], + [AC_RUN_IFELSE([ + AC_LANG_PROGRAM([[ + #include <stdarg.h> + #include <stdlib.h> + ]], + [[ + static void f (int i, ...) { + va_list args1, args2; + va_start (args1, i); + args2 = args1; + if (va_arg (args2, int) != 42 || va_arg (args1, int) != 42) + exit (1); + va_end (args1); va_end (args2); + } + int main() { + f (0, 42); + return 0; + } + ]]) + ], + [dbus_cv_va_val_copy=yes], + [dbus_cv_va_val_copy=no], + [dbus_cv_va_val_copy=yes]) + ]) + AC_LANG_POP([C]) + AS_IF([test "x$dbus_cv_va_val_copy" = "xno"], + [AC_DEFINE([DBUS_VA_COPY_AS_ARRAY], 1, [Define if 'va_list' cannot be copied as a value])]) + ]) #### Atomic integers |