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Diffstat (limited to 'gl/m4/warnings.m4')
| -rw-r--r-- | gl/m4/warnings.m4 | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/gl/m4/warnings.m4 b/gl/m4/warnings.m4 new file mode 100644 index 0000000..9433cb5 --- /dev/null +++ b/gl/m4/warnings.m4 @@ -0,0 +1,176 @@ +# warnings.m4 serial 19 +dnl Copyright (C) 2008-2023 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: |