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author | John Zaitseff <J.Zaitseff@zap.org.au> | 2018-08-06 14:27:17 +1000 |
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committer | Peter Simons <simons@cryp.to> | 2019-02-14 10:07:16 +0100 |
commit | 3984a74baaf4f85a313b0b9bd8d2709f736c7a73 (patch) | |
tree | 450498d117cc42a5fa97f560664555eeebc4b344 /m4/ax_prepend_flag.m4 | |
parent | fc51f04b63b105822ea798b96bcd607c6d2f7212 (diff) | |
download | autoconf-archive-3984a74baaf4f85a313b0b9bd8d2709f736c7a73.tar.gz |
ax_prepend_flag.m4: New macro AX_PREPEND_FLAG
The AX_PREPEND_FLAG macro adds a flag to the front of a flags shell
variable, similar to how AX_APPEND_FLAG adds such flags to the end. It
should be used when adding compiler options that are position dependent:
where those options that were previously defined (such as by the user on
the command line) should override thoses added with AX_PREPEND_FLAG.
Diffstat (limited to 'm4/ax_prepend_flag.m4')
-rw-r--r-- | m4/ax_prepend_flag.m4 | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/m4/ax_prepend_flag.m4 b/m4/ax_prepend_flag.m4 new file mode 100644 index 0000000..db58186 --- /dev/null +++ b/m4/ax_prepend_flag.m4 @@ -0,0 +1,51 @@ +# =========================================================================== +# https://www.gnu.org/software/autoconf-archive/ax_prepend_flag.html +# =========================================================================== +# +# SYNOPSIS +# +# AX_PREPEND_FLAG(FLAG, [FLAGS-VARIABLE]) +# +# DESCRIPTION +# +# FLAG is added to the front of the FLAGS-VARIABLE shell variable, with a +# space added in between. +# +# If FLAGS-VARIABLE is not specified, the current language's flags (e.g. +# CFLAGS) is used. FLAGS-VARIABLE is not changed if it already contains +# FLAG. If FLAGS-VARIABLE is unset in the shell, it is set to exactly +# FLAG. +# +# NOTE: Implementation based on AX_APPEND_FLAG. +# +# LICENSE +# +# Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de> +# Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com> +# Copyright (c) 2018 John Zaitseff <J.Zaitseff@zap.org.au> +# +# 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 1 + +AC_DEFUN([AX_PREPEND_FLAG], +[dnl +AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_SET_IF +AS_VAR_PUSHDEF([FLAGS], [m4_default($2,_AC_LANG_PREFIX[FLAGS])]) +AS_VAR_SET_IF(FLAGS,[ + AS_CASE([" AS_VAR_GET(FLAGS) "], + [*" $1 "*], [AC_RUN_LOG([: FLAGS already contains $1])], + [ + FLAGS="$1 $FLAGS" + AC_RUN_LOG([: FLAGS="$FLAGS"]) + ]) + ], + [ + AS_VAR_SET(FLAGS,[$1]) + AC_RUN_LOG([: FLAGS="$FLAGS"]) + ]) +AS_VAR_POPDEF([FLAGS])dnl +])dnl AX_PREPEND_FLAG |