3 # Copyright © 2011-2014, 2020-2022 Nick Bowler
5 # Prepare the Gnulib tree for inclusion into a non-recursive automake build.
6 # While the output of gnulib-tool is "include"-able if the --makefile-name
7 # option is used, it is still not suitable for non-recursive use for a couple
8 # reasons; chief among them is that filenames are not relative to the top
11 # This script postprocesses the gnulib-tool output to produce something
12 # that is intended to be suitable for inclusion into such non-recursive
13 # build environments. Since the integration involves both configure.ac
14 # and Makefile.am, the output must be included into _both_. Supposing
15 # the output is written to lib/gnulib.mk, you would add:
17 # m4_include([lib/gnulib.mk]) # to configure.ac, after any call to gl_INIT
18 # include $(top_srcdir)/lib/gnulib.mk # to Makefile.am
20 # You must also arrange for the Gnulib-generated header files to be built
21 # before the object files which depend on them; the most robust way to do
22 # this is by explicit prerequisites, for example:
25 # $(foo_OBJECTS): $(gnulib_headers)
27 # The $(gnulib_headers) variable will expand to GNU-make order-only
28 # prerequisites when available, avoiding spurious incremental rebuilds when
29 # unused headers are changed. If this feature is not available, it will
30 # expand to ordinary prerequisites. It is therefore only appropriate for
31 # use in target prerequisites; the $(gnulib_raw_headers) variable may be
32 # used in other contexts when only the list of header files is required.
34 # This script also provides machinery for Gnulib symbol renaming via the
35 # glconfig.mk Makefile.am snippet; use of this feature is optional.
37 # Most of the specific transformations are documented below.
39 # License WTFPL2: Do What The Fuck You Want To Public License, version 2.
40 # This is free software: you are free to do what the fuck you want to.
41 # There is NO WARRANTY, to the extent permitted by law.
49 my $use_libtool = undef;
50 my $for_library = undef;
54 Getopt::Long::Configure("gnu_getopt", "no_auto_abbrev");
56 "o|output=s" => \$output,
57 "i|input=s" => \$input,
58 "library" => sub { $for_library = 1; },
59 "program" => sub { $for_library = 0; },
62 open STDOUT, ">", $output or die "$output: $!\n" if (defined $output);
63 open STDIN, "<", $input or die "$input: $!\n" if (defined $input);
65 my $printed_header = 0;
68 # Hashes to record make variables used in the automake source. The allvars
69 # hash contains variables actually assigned in the Makefile, sourcevars
70 # contains variables used as filenames. Keys are the variable name, and
71 # the value is always set to 1.
72 my (%allvars, %sourcevars);
81 $file =~ m|(?:.+/)?([^/]+)/?|;
88 if ($word =~ /^\$\(([[:word:].]+)\)$/) {
89 # Don't touch variables now, but record them for later.
91 } elsif ($word =~ /^\$\((?:top_)?(?:srcdir|builddir)\)/) {
92 # Do nothing. Generic transformation will take care of
93 # $(srcdir) and $(builddir).
94 } elsif ($word =~ /^[[:word:].+\/-]+$/) {
95 # Mangle the filename. Assume that all relevant files start
96 # with a non-dot (so we don't transform suffix rules) and
97 # contain at least one dot (so we don't transform phony rules).
98 $word = "lib/$word" if ($word =~ /^[^.]+\./);
100 print STDERR "$0:$line: warning: unrecognized source file: $word\n";
106 sub mangle_variable {
109 $raw =~ /([^=]+=)[[:space:]]*(.*)/s;
110 my ($left, @right) = ($1, split(/[[:space:]]+/, $2));
112 return join(" ", ($left, map(mangle_file($_), @right))) . "\n";
118 $raw =~ /([^:]+):[[:space:]]*(.*)/s;
119 my @left = split(/[[:space:]]+/, $1);
120 my @right = split(/[[:space:]]+/, $2);
122 @left = map(mangle_file($_), @left);
123 @right = map(mangle_file($_), @right);
125 return join(" ", @left) . ": " . join(" ", @right) . "\n";
131 # Combine line splices.
139 if (!$printed_header) {
140 print "# Postprocessed by ", basename($0), "\n\n";
142 # BEGIN AUTOMAKE/M4 POLYGLOT \
143 m4_unquote(m4_argn([2], [
144 .PHONY: # Automake code follows
146 # This trick should define gnulib_orderonly to | iff we're using GNU make.
147 gnulib_make_features = $(.FEATURES)
148 gnulib_have_orderonly = $(findstring order-only,${gnulib_make_features})
149 gnulib_orderonly = $(gnulib_have_orderonly:order-only=|)
150 gnulib_core_headers =
151 gnulib_raw_headers = $(gnulib_core_headers)
152 gnulib_headers = $(gnulib_orderonly) $(gnulib_raw_headers)
154 # Oddly, gnulib tries to add to MOSTLYCLEANDIRS (which is *not* an automake
155 # variable) without defining it.
163 # Locate the libgnu definition to determine whether or not the user is
164 # using libtool mode in gnulib-tool. Default to program mode if they
165 # are not, which will avoid pulling in the glsym dependencies.
167 # Convert noinst to EXTRA, that way libgnu will not be built unless
168 # something actually depends on it (which is typically the case).
169 if (/^noinst_LIBRARIES.*libgnu.a/) {
174 if (/^noinst_LTLIBRARIES.*libgnu.la/) {
180 # For some reason, gnulib-tool adds core dumps to "make mostlyclean".
181 # Since these files are (hopefully!) not created by make, they should
183 drop if (/^MOSTLYCLEANFILES.*core/);
185 # Some modules set AM_CPPFLAGS/AM_CFLAGS/etc. in a manner that is not
186 # useful for non-recursive builds. Strip them out.
187 drop if (/^(AM_CPPFLAGS|AM_CFLAGS)/);
189 # We don't care about upstream warning flags that just result in adding
190 # massive amounts of additional build rules for no reason.
192 s/ *\$\(GL_CFLAG_GNULIB_WARNINGS\)// if /_CFLAGS\s*=/;
195 # Drop superfluous CFLAGS assignments (which may be created by above
197 drop if /_CFLAGS\s*=\s*\$\(AM_CFLAGS\)\s*$/;
199 # Library dependencies are added automatically to libgnu.la by
200 # gnulib-tool. Unfortunately, this means that everything linking
201 # against libgnu.la is forced to pull in the same deps, even if they're
202 # unneeded. Furthermore, a libtool linker flag reordering bug prevents
203 # --as-needed from stripping out the useless deps, so it's better to
204 # handle them all manually.
207 # Current uses of SUFFIXES in gnulib are pointless since Automake will
208 # figure it out all on its own. Strip it out.
209 drop if (/SUFFIXES/);
211 # Rewrite automake hook targets to be more generic.
212 if (s/^(.*)-local:/\1-gnulib:/) {
213 print ".PHONY: $1-gnulib\n";
214 print "$1-local: $1-gnulib\n";
218 # We need to mangle filenames in make variables; prepending a lib/ on
219 # relative paths. The following should catch all variable assignments
220 # that need mangling.
221 if (/^([[:word:]]+)[[:space:]]*\+?=/) {
224 if ($1 =~ /(_SOURCES|CLEANFILES|EXTRA_DIST|[[:upper:]]+_H)$/) {
225 $_ = mangle_variable($_);
229 # BUILT_SOURCES has similar problems to recursive make: inadequate
230 # dependencies lead to incorrect builds. Collect them into an
231 # ordinary variable so we can deal with them later.
232 s/BUILT_SOURCES/gnulib_core_headers/;
234 # Targets are similar to variables: the target and its dependencies
235 # need to be mangled.
237 $_ = mangle_target($_);
240 # MKDIR_P commands need to be fixed up; in principle Gnulib could also
241 # be patched here to use $(@D) instead (and thus automatically benefit
242 # from the target being fixed up), but this will do for now.
243 s/^(\t.*\$\(MKDIR_P\)) ([[:alnum:]]+)$/\1 lib\/\2/;
245 # When using conditional-dependencies, *CLEANFILES can end up
246 # depending on the configuration. This means that "make distclean"
247 # may not actually delete everything if the configuration changes
248 # after building the package. Stash all the variables for later so
249 # they can be moved outside of any conditional.
250 if (/(CLEANFILES|CLEANDIRS)[[:space:]]*\+=/) {
251 push(@cleanfiles, $_);
255 # Change t-$@ to $@-t as the former will break if $@ has a directory
259 # Finally, $(srcdir), $(builddir) and %reldir% need to be fixed up.
260 s:\$\(srcdir\):\$\(top_srcdir\)/lib:g;
261 s:\$\(builddir\):\$\(top_builddir\)/lib:g;
263 } continue { s/(\n.)/\\\1/g; print; };
265 print <<'EOF' if ($use_libtool);
266 gnulib_lt_objects = $(libgnu_la_OBJECTS) $(gl_LTLIBOBJS)
267 gnulib_objects = $(gnulib_lt_objects)
268 gnulib_all_symfiles = $(gnulib_lt_objects:.lo=.glsym)
269 $(gnulib_objects): $(gnulib_headers)
271 print <<'EOF' if (!$use_libtool);
272 gnulib_objects = $(libgnu_a_OBJECTS) $(gl_LIBOBJS)
273 gnulib_all_symfiles = $(gnulib_objects:.@OBJEXT@=.glsym)
274 $(gnulib_objects): $(gnulib_headers)
281 ], [dnl M4 code follows
283 AC_SUBST([GLSRC], [lib])
284 AC_CONFIG_LIBOBJ_DIR([lib])
286 AC_DEFUN_ONCE([DX_GLSYM_PREFIX],
287 [AC_REQUIRE([DX_AUTOMAKE_COMPAT])AC_REQUIRE([DX_EXPORTED_SH])dnl
288 AC_SUBST([GLSYM_PREFIX], [$1])dnl
289 AC_SUBST([gnulib_symfiles], ['$(gnulib_all_symfiles)'])])
292 print <<'EOF' if ($for_library);
293 AC_CONFIG_COMMANDS_PRE([DX_GLSYM_PREFIX([${PACKAGE}__])])
297 m4_foreach([gl_objvar], [[gl_LIBOBJS], [gl_LTLIBOBJS]], [dnl
298 set x $gl_objvar; shift
300 while test ${#} -gt 0; do
301 gl_objvar="$gl_objvar lib/${1}"; shift
306 # Some filenames are AC_SUBSTed by the Gnulib macros, and thus we need to
307 # prepend lib/ if and only if they're not empty. Unfortunately, make is not
308 # powerful to do this, so we need to put this transformation into configure
309 # itself by defining a new autoconf macro.
311 foreach (keys %sourcevars) {
312 print "$_=\${$_:+lib/\$$_}\n" unless $allvars{$_};
319 # END AUTOMAKE/M4 POLYGLOT