| 1 | # =========================================================================== |
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| 2 | # https://www.gnu.org/software/autoconf-archive/ax_check_link_flag.html |
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| 3 | # =========================================================================== |
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| 4 | # |
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| 5 | # SYNOPSIS |
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| 6 | # |
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| 7 | # AX_CHECK_LINK_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS], [INPUT]) |
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| 8 | # |
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| 9 | # DESCRIPTION |
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| 10 | # |
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| 11 | # Check whether the given FLAG works with the linker or gives an error. |
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| 12 | # (Warnings, however, are ignored) |
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| 13 | # |
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| 14 | # ACTION-SUCCESS/ACTION-FAILURE are shell commands to execute on |
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| 15 | # success/failure. |
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| 16 | # |
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| 17 | # If EXTRA-FLAGS is defined, it is added to the linker's default flags |
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| 18 | # when the check is done. The check is thus made with the flags: "LDFLAGS |
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| 19 | # EXTRA-FLAGS FLAG". This can for example be used to force the linker to |
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| 20 | # issue an error when a bad flag is given. |
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| 21 | # |
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| 22 | # INPUT gives an alternative input source to AC_LINK_IFELSE. |
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| 23 | # |
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| 24 | # NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this |
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| 25 | # macro in sync with AX_CHECK_{PREPROC,COMPILE}_FLAG. |
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| 26 | # |
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| 27 | # LICENSE |
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| 28 | # |
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| 29 | # Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de> |
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| 30 | # Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com> |
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| 31 | # |
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| 32 | # Copying and distribution of this file, with or without modification, are |
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| 33 | # permitted in any medium without royalty provided the copyright notice |
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| 34 | # and this notice are preserved. This file is offered as-is, without any |
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| 35 | # warranty. |
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| 36 | |
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| 37 | #serial 6 |
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| 38 | |
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| 39 | AC_DEFUN([AX_CHECK_LINK_FLAG], |
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| 40 | [AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF |
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| 41 | AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_ldflags_$4_$1])dnl |
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| 42 | AC_CACHE_CHECK([whether the linker accepts $1], CACHEVAR, [ |
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| 43 | ax_check_save_flags=$LDFLAGS |
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| 44 | LDFLAGS="$LDFLAGS $4 $1" |
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| 45 | AC_LINK_IFELSE([m4_default([$5],[AC_LANG_PROGRAM()])], |
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| 46 | [AS_VAR_SET(CACHEVAR,[yes])], |
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| 47 | [AS_VAR_SET(CACHEVAR,[no])]) |
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| 48 | LDFLAGS=$ax_check_save_flags]) |
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| 49 | AS_VAR_IF(CACHEVAR,yes, |
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| 50 | [m4_default([$2], :)], |
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| 51 | [m4_default([$3], :)]) |
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| 52 | AS_VAR_POPDEF([CACHEVAR])dnl |
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| 53 | ])dnl AX_CHECK_LINK_FLAGS |
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