diff options
Diffstat (limited to 'm4/ax_compiler_flags_ldflags.m4')
| -rw-r--r-- | m4/ax_compiler_flags_ldflags.m4 | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/m4/ax_compiler_flags_ldflags.m4 b/m4/ax_compiler_flags_ldflags.m4 new file mode 100644 index 0000000..f393ba4 --- /dev/null +++ b/m4/ax_compiler_flags_ldflags.m4 @@ -0,0 +1,75 @@ +# ============================================================================= +# http://www.gnu.org/software/autoconf-archive/ax_compiler_flags_ldflags.html +# ============================================================================= +# +# SYNOPSIS +# +# AX_COMPILER_FLAGS_LDFLAGS([VARIABLE], [IS-RELEASE], [EXTRA-BASE-FLAGS], [EXTRA-YES-FLAGS]) +# +# DESCRIPTION +# +# Add warning flags for the linker to VARIABLE, which defaults to +# WARN_LDFLAGS. VARIABLE is AC_SUBST-ed by this macro, but must be +# manually added to the LDFLAGS variable for each target in the code base. +# +# This macro depends on the environment set up by AX_COMPILER_FLAGS. +# Specifically, it uses the value of $ax_enable_compile_warnings to decide +# which flags to enable. +# +# LICENSE +# +# Copyright (c) 2014, 2015 Philip Withnall <philip@tecnocode.co.uk> +# +# Copying and distribution of this file, with or without modification, are +# permitted in any medium without royalty provided the copyright notice +# and this notice are preserved. This file is offered as-is, without any +# warranty. + +#serial 4 + +AC_DEFUN([AX_COMPILER_FLAGS_LDFLAGS],[ + AX_REQUIRE_DEFINED([AX_APPEND_COMPILE_FLAGS]) + AX_REQUIRE_DEFINED([AX_APPEND_FLAG]) + AX_REQUIRE_DEFINED([AX_CHECK_COMPILE_FLAG]) + + # Variable names + m4_define(ax_warn_ldflags_variable, + [m4_normalize(ifelse([$1],,[WARN_LDFLAGS],[$1]))]) + + # Always pass -Werror=unknown-warning-option to get Clang to fail on bad + # flags, otherwise they are always appended to the warn_ldflags variable, + # and Clang warns on them for every compilation unit. + # If this is passed to GCC, it will explode, so the flag must be enabled + # conditionally. + AX_CHECK_COMPILE_FLAG([-Werror=unknown-warning-option],[ + ax_compiler_flags_test="-Werror=unknown-warning-option" + ],[ + ax_compiler_flags_test="" + ]) + + # Base flags + AX_APPEND_COMPILE_FLAGS([ dnl + -Wl,--no-as-needed dnl + $3 dnl + ],ax_warn_ldflags_variable,[$ax_compiler_flags_test]) + + AS_IF([test "$ax_enable_compile_warnings" != "no"],[ + # "yes" flags + AX_APPEND_COMPILE_FLAGS([$4 $5 $6 $7], + ax_warn_ldflags_variable, + [$ax_compiler_flags_test]) + ]) + AS_IF([test "$ax_enable_compile_warnings" = "error"],[ + # "error" flags; -Werror has to be appended unconditionally because + # it's not possible to test for + # + # suggest-attribute=format is disabled because it gives too many false + # positives + AX_APPEND_COMPILE_FLAGS([ dnl + -Wl,--fatal-warnings dnl + ],ax_warn_ldflags_variable,[$ax_compiler_flags_test]) + ]) + + # Substitute the variables + AC_SUBST(ax_warn_ldflags_variable) +])dnl AX_COMPILER_FLAGS |