diff options
Diffstat (limited to 'configure.ac')
| -rw-r--r-- | configure.ac | 31 |
1 files changed, 28 insertions, 3 deletions
diff --git a/configure.ac b/configure.ac index 15b4ba4c..cf226b29 100644 --- a/configure.ac +++ b/configure.ac @@ -768,6 +768,29 @@ AC_CHECK_MEMBERS([ AC_SYS_LARGEFILE AC_C_BIGENDIAN +# __attribute__((__constructor__)) can be used for one-time initializations. +# Use -Werror because some compilers accept unknown attributes and just +# give a warning. If it works this should give no warnings, even +# clang -Weverything should be fine. +# dnl This doesn't need AC_LANG_SOURCE, minimal code is enough. +AC_MSG_CHECKING([if __attribute__((__constructor__)) can be used]) +have_func_attribute_constructor=no +OLD_CFLAGS="$CFLAGS" +CFLAGS="$CFLAGS -Werror" +AC_COMPILE_IFELSE([ + __attribute__((__constructor__)) + static void my_constructor_func(void) { return; } +], [ + AC_DEFINE([HAVE_FUNC_ATTRIBUTE_CONSTRUCTOR], [1], + [Define to 1 if __attribute__((__constructor__)) + is supported for functions.]) + have_func_attribute_constructor=yes + AC_MSG_RESULT([yes]) +], [ + AC_MSG_RESULT([no]) +]) +CFLAGS="$OLD_CFLAGS" + ############################################################################### # Checks for library functions. @@ -1005,9 +1028,11 @@ if test x$tuklib_cv_cpucores_method = xunknown; then echo "No supported method to detect the number of CPU cores." fi -if test "x$enable_threads$enable_small" = xnoyes; then +if test "x$enable_threads$enable_small$have_func_attribute_constructor" \ + = xnoyesno; then echo echo "NOTE:" - echo "liblzma will be thread unsafe due the combination" - echo "of --disable-threads --enable-small." + echo "liblzma will be thread-unsafe due to the combination" + echo "of --disable-threads --enable-small when using a compiler" + echo "that doesn't support __attribute__((__constructor__))." fi |