diff options
Diffstat (limited to 'm4/manywarnings.m4')
| -rw-r--r-- | m4/manywarnings.m4 | 32 |
1 files changed, 25 insertions, 7 deletions
diff --git a/m4/manywarnings.m4 b/m4/manywarnings.m4 index 2760efb3f27..f3cb23be1cd 100644 --- a/m4/manywarnings.m4 +++ b/m4/manywarnings.m4 @@ -1,4 +1,4 @@ -# manywarnings.m4 serial 4 +# manywarnings.m4 serial 5 dnl Copyright (C) 2008-2012 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, @@ -35,14 +35,12 @@ AC_DEFUN([gl_MANYWARN_COMPLEMENT], # make sure your gcc understands it. AC_DEFUN([gl_MANYWARN_ALL_GCC], [ - dnl First, check if -Wno-missing-field-initializers is needed. - dnl -Wmissing-field-initializers is implied by -W, but that issues - dnl warnings with GCC version before 4.7, for the common idiom - dnl of initializing types on the stack to zero, using { 0, } + dnl First, check for some issues that only occur when combining multiple + dnl gcc warning categories. AC_REQUIRE([AC_PROG_CC]) if test -n "$GCC"; then - dnl First, check -W -Werror -Wno-missing-field-initializers is supported + dnl Check if -W -Werror -Wno-missing-field-initializers is supported dnl with the current $CC $CFLAGS $CPPFLAGS. AC_MSG_CHECKING([whether -Wno-missing-field-initializers is supported]) AC_CACHE_VAL([gl_cv_cc_nomfi_supported], [ @@ -77,8 +75,24 @@ AC_DEFUN([gl_MANYWARN_ALL_GCC], ]) AC_MSG_RESULT([$gl_cv_cc_nomfi_needed]) fi + + dnl Next, check if -Werror -Wuninitialized is useful with the + dnl user's choice of $CFLAGS; some versions of gcc warn that it + dnl has no effect if -O is not also used + AC_MSG_CHECKING([whether -Wuninitialized is supported]) + AC_CACHE_VAL([gl_cv_cc_uninitialized_supported], [ + gl_save_CFLAGS="$CFLAGS" + CFLAGS="$CFLAGS -Werror -Wuninitialized" + AC_COMPILE_IFELSE( + [AC_LANG_PROGRAM([[]], [[]])], + [gl_cv_cc_uninitialized_supported=yes], + [gl_cv_cc_uninitialized_supported=no]) + CFLAGS="$gl_save_CFLAGS"]) + AC_MSG_RESULT([$gl_cv_cc_uninitialized_supported]) + fi + # List all gcc warning categories. gl_manywarn_set= for gl_manywarn_item in \ -W \ @@ -197,10 +211,14 @@ AC_DEFUN([gl_MANYWARN_ALL_GCC], gl_manywarn_set="$gl_manywarn_set $gl_manywarn_item" done - # Disable the missing-field-initializers warning if needed + # Disable specific options as needed. if test "$gl_cv_cc_nomfi_needed" = yes; then gl_manywarn_set="$gl_manywarn_set -Wno-missing-field-initializers" fi + if test "$gl_cv_cc_uninitialized_supported" = no; then + gl_manywarn_set="$gl_manywarn_set -Wno-uninitialized" + fi + $1=$gl_manywarn_set ]) |