# warnings.m4 serial 19 dnl Copyright (C) 2008-2024 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, dnl with or without modifications, as long as this notice is preserved. dnl From Simon Josefsson AC_PREREQ([2.64]) # gl_COMPILER_OPTION_IF(OPTION, [IF-SUPPORTED], [IF-NOT-SUPPORTED], # [PROGRAM = AC_LANG_PROGRAM()]) # ----------------------------------------------------------------- # Check if the compiler supports OPTION when compiling PROGRAM. # # The effects of this macro depend on the current language (_AC_LANG). AC_DEFUN([gl_COMPILER_OPTION_IF], [ AS_VAR_PUSHDEF([gl_Warn], [gl_cv_warn_[]_AC_LANG_ABBREV[]_$1])dnl AS_VAR_PUSHDEF([gl_Flags], [_AC_LANG_PREFIX[]FLAGS])dnl AS_LITERAL_IF([$1], [m4_pushdef([gl_Positive], m4_bpatsubst([$1], [^-Wno-], [-W]))], [gl_positive="$1" case $gl_positive in -Wno-*) gl_positive=-W`expr "X$gl_positive" : 'X-Wno-\(.*\)'` ;; esac m4_pushdef([gl_Positive], [$gl_positive])])dnl AC_CACHE_CHECK([whether _AC_LANG compiler handles $1], [gl_Warn], [ gl_save_compiler_FLAGS="$gl_Flags" AS_VAR_APPEND(m4_defn([gl_Flags]), [" $gl_unknown_warnings_are_errors ]m4_defn([gl_Positive])["]) AC_LINK_IFELSE([m4_default([$4], [AC_LANG_PROGRAM([[]])])], [AS_VAR_SET([gl_Warn], [yes])], [AS_VAR_SET([gl_Warn], [no])]) gl_Flags="$gl_save_compiler_FLAGS" ]) AS_VAR_IF(gl_Warn, [yes], [$2], [$3]) m4_popdef([gl_Positive])dnl AS_VAR_POPDEF([gl_Flags])dnl AS_VAR_POPDEF([gl_Warn])dnl ]) # gl_UNKNOWN_WARNINGS_ARE_ERRORS # ------------------------------ # Clang doesn't complain about unknown warning options unless one also # specifies -Wunknown-warning-option -Werror. Detect this. # # The effects of this macro depend on the current language (_AC_LANG). AC_DEFUN([gl_UNKNOWN_WARNINGS_ARE_ERRORS], [_AC_LANG_DISPATCH([$0], _AC_LANG, $@)]) # Specialization for _AC_LANG = C. This macro can be AC_REQUIREd. AC_DEFUN([gl_UNKNOWN_WARNINGS_ARE_ERRORS(C)], [ AC_LANG_PUSH([C]) gl_UNKNOWN_WARNINGS_ARE_ERRORS_IMPL AC_LANG_POP([C]) ]) # Specialization for _AC_LANG = C++. This macro can be AC_REQUIREd. AC_DEFUN([gl_UNKNOWN_WARNINGS_ARE_ERRORS(C++)], [ AC_LANG_PUSH([C++]) gl_UNKNOWN_WARNINGS_ARE_ERRORS_IMPL AC_LANG_POP([C++]) ]) # Specialization for _AC_LANG = Objective C. This macro can be AC_REQUIREd. AC_DEFUN([gl_UNKNOWN_WARNINGS_ARE_ERRORS(Objective C)], [ AC_LANG_PUSH([Objective C]) gl_UNKNOWN_WARNINGS_ARE_ERRORS_IMPL AC_LANG_POP([Objective C]) ]) AC_DEFUN([gl_UNKNOWN_WARNINGS_ARE_ERRORS_IMPL], [gl_COMPILER_OPTION_IF([-Werror -Wunknown-warning-option], [gl_unknown_warnings_are_errors='-Wunknown-warning-option -Werror'], [gl_unknown_warnings_are_errors=])]) # gl_WARN_ADD(OPTION, [VARIABLE = WARN_CFLAGS/WARN_CXXFLAGS], # [PROGRAM = AC_LANG_PROGRAM()]) # ----------------------------------------------------------- # Adds OPTION to VARIABLE (which defaults to WARN_CFLAGS or WARN_CXXFLAGS) # if the compiler supports it when compiling PROGRAM. # # If VARIABLE is a variable name, AC_SUBST it. # # The effects of this macro depend on the current language (_AC_LANG). # # Example: gl_WARN_ADD([-Wparentheses]). AC_DEFUN([gl_WARN_ADD], [AC_REQUIRE([gl_UNKNOWN_WARNINGS_ARE_ERRORS(]_AC_LANG[)]) gl_COMPILER_OPTION_IF([$1], [AS_VAR_APPEND(m4_if([$2], [], [[WARN_]_AC_LANG_PREFIX[FLAGS]], [[$2]]), [" $1"])], [], [$3]) m4_ifval([$2], [AS_LITERAL_IF([$2], [AC_SUBST([$2])])], [AC_SUBST([WARN_]_AC_LANG_PREFIX[FLAGS])])dnl ]) # gl_CC_INHIBIT_WARNINGS # sets and substitutes a variable GL_CFLAG_INHIBIT_WARNINGS, to a $(CC) option # that reverts all preceding -W* options, if available. # This is expected to be '-w' at least on gcc, clang, AIX xlc, xlclang, Sun cc, # "compile cl" (MSVC), "compile clang-cl" (MSVC-compatible clang). Or it can be # empty. AC_DEFUN([gl_CC_INHIBIT_WARNINGS], [ AC_REQUIRE([AC_PROG_CC]) AC_CACHE_CHECK([for C compiler option to inhibit all warnings], [gl_cv_cc_winhibit], [rm -f conftest* echo 'int dummy;' > conftest.c AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS -c conftest.c 2>conftest1.err]) >/dev/null AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS -w -c conftest.c 2>conftest2.err]) >/dev/null if test $? = 0 && test `wc -l < conftest1.err` = `wc -l < conftest2.err`; then gl_cv_cc_winhibit='-w' else gl_cv_cc_winhibit=none fi rm -f conftest* ]) case "$gl_cv_cc_winhibit" in none) GL_CFLAG_INHIBIT_WARNINGS='' ;; *) GL_CFLAG_INHIBIT_WARNINGS="$gl_cv_cc_winhibit" dnl If all warnings are inhibited, there's no point in having the GCC dnl analyzer enabled. This saves RAM requirements and CPU consumption. gl_WARN_ADD([-fno-analyzer], [GL_CFLAG_INHIBIT_WARNINGS]) ;; esac AC_SUBST([GL_CFLAG_INHIBIT_WARNINGS]) ]) # gl_CXX_INHIBIT_WARNINGS # sets and substitutes a variable GL_CXXFLAG_INHIBIT_WARNINGS, to a $(CC) option # that reverts all preceding -W* options, if available. AC_DEFUN([gl_CXX_INHIBIT_WARNINGS], [ dnl Requires AC_PROG_CXX or gl_PROG_ANSI_CXX. if test -n "$CXX" && test "$CXX" != no; then AC_CACHE_CHECK([for C++ compiler option to inhibit all warnings], [gl_cv_cxx_winhibit], [rm -f conftest* echo 'int dummy;' > conftest.cc AC_TRY_COMMAND([${CXX-c++} $CXXFLAGS $CPPFLAGS -c conftest.cc 2>conftest1.err]) >/dev/null AC_TRY_COMMAND([${CXX-c++} $CXXFLAGS $CPPFLAGS -w -c conftest.cc 2>conftest2.err]) >/dev/null if test $? = 0 && test `wc -l < conftest1.err` = `wc -l < conftest2.err`; then gl_cv_cxx_winhibit='-w' else gl_cv_cxx_winhibit=none fi rm -f conftest* ]) case "$gl_cv_cxx_winhibit" in none) GL_CXXFLAG_INHIBIT_WARNINGS='' ;; *) GL_CXXFLAG_INHIBIT_WARNINGS="$gl_cv_cxx_winhibit" dnl If all warnings are inhibited, there's no point in having the GCC dnl analyzer enabled. This saves RAM requirements and CPU consumption. gl_WARN_ADD([-fno-analyzer], [GL_CXXFLAG_INHIBIT_WARNINGS]) ;; esac else GL_CXXFLAG_INHIBIT_WARNINGS='' fi AC_SUBST([GL_CXXFLAG_INHIBIT_WARNINGS]) ]) # Local Variables: # mode: autoconf # End: