diff options
Diffstat (limited to 'm4/compiler_options.m4')
| -rw-r--r-- | m4/compiler_options.m4 | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/m4/compiler_options.m4 b/m4/compiler_options.m4 new file mode 100644 index 0000000000..3d2e4dbefc --- /dev/null +++ b/m4/compiler_options.m4 @@ -0,0 +1,110 @@ +AC_DEFUN([_NM_COMPILER_FLAG], [ + CFLAGS_SAVED="$CFLAGS" + CFLAGS="$CFLAGS $GLIB_CFLAGS -Werror $1" + AC_MSG_CHECKING([whether $1 works as expected]) + + AC_COMPILE_IFELSE([AC_LANG_SOURCE([[]])], [ + AC_COMPILE_IFELSE([AC_LANG_SOURCE([[$2]])], [ + AC_MSG_RESULT(yes) + CFLAGS="$CFLAGS_SAVED" + $3 + ],[ + AC_MSG_RESULT(no) + CFLAGS="$CFLAGS_SAVED" + $4 + ]) + ],[ + AC_MSG_RESULT(not supported) + CFLAGS="$CFLAGS_SAVED" + ]) +]) + +dnl Check whether a particular compiler flag is supported, +dnl add it to CFLAGS if it is +AC_DEFUN([NM_COMPILER_FLAG], [ + _NM_COMPILER_FLAG([$1], [], [ + CFLAGS="$CFLAGS $1" + $2 + ], [$3]) +]) + +dnl Check whether a particular warning is not emitted with code provided, +dnl disable it in CFLAGS if the check fails. +AC_DEFUN([NM_COMPILER_WARNING], [ + _NM_COMPILER_FLAG([-W$1], [$2], [CFLAGS="$CFLAGS -W$1"], [CFLAGS="$CFLAGS -Wno-$1"]) +]) + +AC_DEFUN([NM_COMPILER_WARNINGS], +[AC_ARG_ENABLE(more-warnings, + AS_HELP_STRING([--enable-more-warnings], [Possible values: no/yes/error]), + set_more_warnings="$enableval",set_more_warnings=yes) +AC_MSG_CHECKING(for more warnings) +if test "$GCC" = "yes" -a "$set_more_warnings" != "no"; then + AC_MSG_RESULT(yes) + + dnl This is enabled in clang by default, makes little sense, + dnl and causes the build to abort with -Werror. + CFLAGS_SAVED="$CFLAGS" + CFLAGS="$CFLAGS -Qunused-arguments" + AC_COMPILE_IFELSE([AC_LANG_SOURCE([])], [], CFLAGS="$CFLAGS_SAVED") + unset CFLAGS_SAVED + + dnl clang only warns about unknown warnings, unless + dnl called with "-Werror=unknown-warning-option" + dnl Test if the compiler supports that, and if it does + dnl attach it to the CFLAGS. + NM_COMPILER_WARNING([unknown-warning-option], []) + + CFLAGS_MORE_WARNINGS="-Wall -std=gnu89" + + if test "x$set_more_warnings" = xerror; then + CFLAGS_MORE_WARNINGS="$CFLAGS_MORE_WARNINGS -Werror" + fi + + for option in -Wshadow -Wmissing-declarations -Wmissing-prototypes \ + -Wdeclaration-after-statement -Wformat-security \ + -Wfloat-equal -Wno-unused-parameter -Wno-sign-compare \ + -Wno-duplicate-decl-specifier \ + -Wstrict-prototypes \ + -fno-strict-aliasing -Wno-unused-but-set-variable \ + -Wundef -Wimplicit-function-declaration \ + -Wpointer-arith -Winit-self \ + -Wmissing-include-dirs -Wno-pragmas; do + dnl GCC 4.4 does not warn when checking for -Wno-* flags (https://gcc.gnu.org/wiki/FAQ#wnowarning) + _NM_COMPILER_FLAG([$(printf '%s' "$option" | sed 's/^-Wno-/-W/')], [], + [CFLAGS_MORE_WARNINGS="$CFLAGS_MORE_WARNINGS $option"], []) + done + unset option + + dnl Disable warnings triggered by known compiler problems + + dnl https://bugzilla.gnome.org/show_bug.cgi?id=745821 + NM_COMPILER_WARNING([unknown-attributes], [#include <glib.h>]) + + dnl https://bugzilla.gnome.org/show_bug.cgi?id=744473 + NM_COMPILER_WARNING([typedef-redefinition], [#include <gio/gio.h>]) + + dnl https://llvm.org/bugs/show_bug.cgi?id=21614 + NM_COMPILER_WARNING([array-bounds], + [#include <string.h>] + [void f () { strcmp ("something", "0"); }] + ) + + dnl https://llvm.org/bugs/show_bug.cgi?id=22949 + NM_COMPILER_WARNING([parentheses-equality], + [#include <sys/wait.h>] + [void f () { if (WIFCONTINUED(0)) return; }] + ) + + dnl systemd-dhcp's log_internal macro and our handle_warn are sometimes + dnl used in void context,u sometimes in int. Makes clang unhappy. + NM_COMPILER_WARNING([unused-value], + [#define yolo ({ (666 + 666); })] + [int f () { int i = yolo; yolo; return i; }] + ) + + CFLAGS="$CFLAGS_MORE_WARNINGS $CFLAGS" +else + AC_MSG_RESULT(no) +fi +]) |