-dnl Copyright © 2012 Nick Bowler
+dnl Copyright © 2012, 2014 Nick Bowler
dnl
-dnl Base definitions for dxcommon.
+dnl Base directory handling for dxcommon.
dnl
dnl License WTFPL2: Do What The Fuck You Want To Public License, version 2.
dnl This is free software: you are free to do what the fuck you want to.
dnl There is NO WARRANTY, to the extent permitted by law.
-m4_pattern_forbid([^_?DX_])
+AC_PREREQ([2.64])
-dnl DX_INIT([directory])
-dnl
-dnl Sets the directory of the dxcommon checkout, which is used by other macros
-dnl to find any source files that they may need. If this file was included
-dnl from its original location using m4_include, which normally happens when
-dnl using aclocal, then the directory will be determined automatically (and
-dnl this macro does not need to be called in configure.ac at all). Otherwise,
-dnl this should be called prior to any other dxcommon macro.
+m4_pattern_forbid([^_?DX_])
+dnl _DX_BASE_FILE
+dnl
+dnl This macro identifies the filename of this file, used to automatically
+dnl determine the dxcommon base directory. It is a literal string, thus it
+dnl should not be expanded directly; use m4_defn([_DX_BASE_FILE]) instead.
m4_define([_DX_BASE_FILE], __file__)
-AC_DEFUN_ONCE([DX_INIT], [dnl
-dnl Care must be taken to avoid spurious expansions of things that look like
-dnl macros in the filename; this is made especially difficult since
-dnl m4_bpatsubst does not expand to a quoted string.
-m4_define([_DX_BASEDIR], m4_if([$1], [],
- [m4_bpatsubst(m4_dquote(m4_defn([_DX_BASE_FILE])),
- [/m4/[^/]*\.m4\(.\)$], [\1])],
- [[$1]]))
+dnl _DX_SET_BASEDIR([directory])
+dnl
+dnl Defines the macro _DX_BASEDIR to the dxcommon base directory. If the
+dnl argument is empty, the base directory will be determined automatically.
+dnl Otherwise, the base directory is set to the argument (which is not
+dnl subject to macro expansion).
+dnl
+dnl Quoting here is tricky as we must avoid macro expansion of _DX_BASE_FILE,
+dnl but m4_bpatsubst does not quote its result. The resulting _DX_BASEDIR
+dnl macro is a literal string, thus it should not be expanded directly; use
+dnl m4_defn([_DX_BASEDIR]) instead.
+m4_define([_DX_SET_BASEDIR], [m4_do(
+ [m4_define([_DX_BASEDIR], m4_ifval([$1], [[$1]],
+ [m4_bpatsubst(m4_dquote(m4_defn([_DX_BASE_FILE])),
+ [/m4/[^/]*\.m4\(.\)$], [\1])]))],
+ [_DX_STAMP])])
-dnl Include the stamp file, which will cause a failure at autoconf time
-dnl if it does not exist in the checkout. We circumvent m4_include to
-dnl avoid warnings about multiple inclusions.
-m4_pushdef([m4_include], [m4_builtin([include], $][@)])
-m4_include(m4_defn([_DX_BASEDIR])[/m4/dx-stamp.m4])
-m4_popdef([m4_include])
-_DX_STAMP_DUMMY
+dnl Include the stamp file to force failure at autoconf time if it does
+dnl not exist in the checkout. We circumvent m4_include to avoid warnings
+dnl about multiple inclusions.
+m4_define([_DX_STAMP], [m4_do(
+ [m4_pushdef([m4_include], [m4_builtin([include], $][@)])],
+ [m4_include(m4_defn([_DX_BASEDIR])[/m4/dx-stamp.m4])],
+ [m4_popdef([m4_include])])])
-dnl Autoconf scripts should use the DX_BASEDIR m4 macro instead of the
-dnl AC_SUBSTed shell variable, but we use the same name for the macro since
-dnl it means the same thing as the substituted variable.
+dnl DX_INIT(directory)
+dnl
+dnl Sets the dxcommon base directory, which is used by other macros to
+dnl find any source files that they may need. It is not normally necessary
+dnl to use this macro. If it used, it must be expanded prior to any other
+dnl dxcommon macro. Otherwise, the base directory will be determined
+dnl automatically.
+dnl
+dnl The directory argument is a literal string, not subject to macro expansion.
dnl
dnl Autoconf versions <= 2.69 have a bug which causes the first argument of
-dnl AC_SUBST to be expanded as a macro when using the two-argument form. So
-dnl until we require a newer version of autoconf, we must use the one-argument
-dnl form of AC_SUBST.
+dnl AC_SUBST to be expanded as a macro when using the two-argument form. This
+dnl bug has been fixed upstream but as of September, 2014 there is no release
+dnl which includes the fix.
+AC_DEFUN_ONCE([DX_INIT], [m4_do(
+ [_DX_SET_BASEDIR([$1])],
+ [AC_SUBST([DX_BASEDIR])],
+ [AC_CONFIG_COMMANDS_PRE(
+ [[DX_BASEDIR]="AS_ESCAPE(m4_dquote(m4_defn([_DX_BASEDIR])))"])])])
-[DX_BASEDIR]="AS_ESCAPE(m4_dquote(m4_defn([_DX_BASEDIR])))"
-m4_pushdef([m4_pattern_allow])
-AC_SUBST([DX_BASEDIR])
-m4_popdef([m4_pattern_allow])
-])
-
-AC_DEFUN([DX_BASEDIR], [dnl
-AC_REQUIRE([DX_INIT])dnl
-m4_defn([_DX_BASEDIR])dnl
-])
+dnl DX_BASEDIR
+dnl
+dnl This macro expands to the dxcommon base directory, as a quoted string.
+AC_DEFUN([DX_BASEDIR], [m4_ignore(DX_INIT())m4_defn([_DX_BASEDIR])])
projects / dxcommon.git / blobdiff