build: Inline perl prototypes in sources

Prototypes allows us to avoid using the '&foo' invocation form when
invoking a subroutine before its definition.  Previously those
prototypes were generated to prevent them from falling out-of-sync
with actual definitions.  Now we provide a 'check-perl-protos' lint
script to ensure that this is not the case.  This has the same
benefits as generating prototypes while simplifying the
bootstrap/build process.

* bin/gen-perl-protos: Remove.
* bin/Makefile.inc: Adapt.
* bootstrap: Likewise.
* bin/aclocal.in: Inline prototypes.
* bin/automake.in: Likewise.
* maintainer/check-perl-protos: New lint script.
* maintainer/syntax-checks.mk (sc_perl_protos): New target.
(syntax_check_rules): Add it.

7 files changed, 136 insertions, 49 deletions

diff --git a/bin/Makefile.inc b/bin/Makefile.inc
index 62dd483d9..c63f670b8 100644
--- a/bin/Makefile.inc
+++ b/bin/Makefile.inc
@@ -61,19 +61,15 @@ uninstall-hook:
 # $(datadir) or other do_subst'ituted variables change.
 %D%/automake: %D%/automake.in
 %D%/aclocal: %D%/aclocal.in
-%D%/automake %D%/aclocal: Makefile %D%/gen-perl-protos
+%D%/automake %D%/aclocal: Makefile
 	$(AM_V_GEN)rm -f $@ $@-t $@-t2 \
 	  && $(MKDIR_P) $(@D) \
 ## Common substitutions.
 	  && in=$@.in && $(do_subst) <$(srcdir)/$$in >$@-t \
-## Auto-compute prototypes of perl subroutines.
-	  && $(PERL) -w $(srcdir)/%D%/gen-perl-protos $@-t > $@-t2 \
-	  && mv -f $@-t2 $@-t \
 ## We can't use '$(generated_file_finalize)' here, because currently
 ## Automake contains occurrences of unexpanded @substitutions@ in
 ## comments, and that is perfectly legit.
 	  && chmod a+x,a-w $@-t && mv -f $@-t $@
-EXTRA_DIST += %D%/gen-perl-protos
 
 %D%/aclocal-$(APIVERSION): %D%/aclocal
 	$(AM_V_GEN) rm -f $@; \
diff --git a/bin/aclocal.in b/bin/aclocal.in
index 738996f39..64fd66233 100644
--- a/bin/aclocal.in
+++ b/bin/aclocal.in
@@ -173,7 +173,26 @@ use constant SCAN_M4_DIRS_ERROR => 2;
 
 # Prototypes for all subroutines.
 
-#! Prototypes here will automatically be generated by the build system.
+sub add_file ($);
+sub add_macro ($);
+sub check_acinclude ();
+sub install_file ($$);
+sub list_compare (\@\@);
+sub parse_ACLOCAL_PATH ();
+sub parse_arguments ();
+sub reset_maps ();
+sub scan_configure ();
+sub scan_configure_dep ($);
+sub scan_file ($$$);
+sub scan_m4_dirs ($$@);
+sub scan_m4_files ();
+sub strip_redundant_includes (%);
+sub trace_used_macros ();
+sub unlink_tmp (;$);
+sub usage ($);
+sub version ();
+sub write_aclocal ($@);
+sub xmkdir_p ($);
 
 ################################################################
 
diff --git a/bin/automake.in b/bin/automake.in
index ad86cf4a8..3433d3de7 100644
--- a/bin/automake.in
+++ b/bin/automake.in
@@ -80,8 +80,61 @@ use Carp;
 ## Subroutine prototypes.  ##
 ## ----------------------- ##
 
-#! Prototypes here will automatically be generated by the build system.
-
+sub append_exeext (&$);
+sub check_gnits_standards ();
+sub check_gnu_standards ();
+sub check_trailing_slash ($\$);
+sub check_typos ();
+sub define_files_variable ($\@$$);
+sub define_standard_variables ();
+sub define_verbose_libtool ();
+sub define_verbose_texinfo ();
+sub do_check_merge_target ();
+sub get_number_of_threads ();
+sub handle_compile ();
+sub handle_data ();
+sub handle_dist ();
+sub handle_emacs_lisp ();
+sub handle_factored_dependencies ();
+sub handle_footer ();
+sub handle_gettext ();
+sub handle_headers ();
+sub handle_install ();
+sub handle_java ();
+sub handle_languages ();
+sub handle_libraries ();
+sub handle_libtool ();
+sub handle_ltlibraries ();
+sub handle_makefiles_serial ();
+sub handle_man_pages ();
+sub handle_minor_options ();
+sub handle_options ();
+sub handle_programs ();
+sub handle_python ();
+sub handle_scripts ();
+sub handle_silent ();
+sub handle_subdirs ();
+sub handle_tags ();
+sub handle_targets ();
+sub handle_tests ();
+sub handle_tests_dejagnu ();
+sub handle_texinfo ();
+sub handle_user_recursion ();
+sub initialize_per_input ();
+sub lang_lex_finish ();
+sub lang_sub_obj ();
+sub lang_vala_finish ();
+sub lang_yacc_finish ();
+sub locate_aux_dir ();
+sub parse_arguments ();
+sub scan_aclocal_m4 ();
+sub scan_autoconf_files ();
+sub silent_flag ();
+sub transform ($\%);
+sub transform_token ($\%$);
+sub usage ();
+sub version ();
+sub yacc_lex_finish_helper ();
 
 ## ----------- ##
 ## Constants.  ##
diff --git a/bin/gen-perl-protos b/bin/gen-perl-protos
deleted file mode 100755
index 215d275b8..000000000
--- a/bin/gen-perl-protos
+++ /dev/null
@@ -1,36 +0,0 @@
-#!/usr/bin/env perl
-#
-# Copyright (C) 2013-2017 Free Software Foundation, Inc.
-#
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; either version 3, or (at your option)
-# any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-use warnings;
-use strict;
-
-my @lines = <>;
-my @protos = map { /^(sub \w+\s*\(.*\))/ ? ("$1;") : () } @lines;
-
-while (defined ($_ = shift @lines))
-  {
-    if (/^#!.* prototypes/i)
-      {
-        print "# BEGIN AUTOMATICALLY GENERATED PROTOTYPES\n";
-        print join ("\n", sort @protos) . "\n";
-        print "# END AUTOMATICALLY GENERATED PROTOTYPES\n";
-      }
-    else
-      {
-        print;
-      }
-  }
diff --git a/bootstrap b/bootstrap
index d0766d4c8..1382a9fe8 100755
--- a/bootstrap
+++ b/bootstrap
@@ -103,11 +103,8 @@ dosubst automake-$APIVERSION/Automake/Config.in \
 dosubst m4/amversion.in m4/amversion.m4
 
 # Create temporary replacement for aclocal and automake.
-for p in bin/aclocal bin/automake; do
-  dosubst $p.in $p.tmp
-  $PERL -w bin/gen-perl-protos $p.tmp > $p.tmp2
-  mv -f $p.tmp2 $p.tmp
-done
+dosubst bin/aclocal.in bin/aclocal.tmp
+dosubst bin/automake.in bin/automake.tmp
 
 # Create required makefile snippets.
 $PERL ./gen-testsuite-part > t/testsuite-part.tmp
diff --git a/maintainer/check-perl-protos b/maintainer/check-perl-protos
new file mode 100755
index 000000000..b1d6a72b5
--- /dev/null
+++ b/maintainer/check-perl-protos
@@ -0,0 +1,50 @@
+#!/usr/bin/env perl
+#
+# Copyright (C) 2017 Free Software Foundation, Inc.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+use warnings;
+use strict;
+
+my @lines = <>;
+my %forwards = map { /^sub (\w+)\s*\((.*)\);$/ ? ("$1" => "$2") : () } @lines;
+my %subs = map { /^sub (\w+)\s*\((.*)\)$/ ? ("$1" => "$2") : () } @lines;
+my $error_count = 0;
+
+# $subs{"foo"} = "$$";
+# $subs{"bar"} = "@";
+# $forwards{"bar"} = "\$";
+
+# Check that every subroutine has a matching forward declaration with
+# the same prototype.
+foreach my $sub (keys (%subs))
+  {
+    # XXX: The location of the subroutine is not reported.
+    if (grep { $sub eq $_ } keys (%forwards))
+      {
+	if ($forwards{$sub} ne $subs{$sub})
+	  {
+	    $error_count += 1;
+	    warn ("prototype mismatch for \"$sub\" subroutine\n");
+	  }
+      }
+    else
+      {
+	$error_count += 1;
+	warn ("missing prototype for \"$sub\" subroutine\n");
+      }
+  }
+
+exit (($error_count == 0) ? 0 : 1);
diff --git a/maintainer/syntax-checks.mk b/maintainer/syntax-checks.mk
index c8b074008..07a12ab6f 100644
--- a/maintainer/syntax-checks.mk
+++ b/maintainer/syntax-checks.mk
@@ -51,6 +51,7 @@ sc_mkinstalldirs \
 sc_pre_normal_post_install_uninstall \
 sc_perl_no_undef \
 sc_perl_no_split_regex_space \
+sc_perl_protos \
 sc_cd_in_backquotes \
 sc_cd_relative_dir \
 sc_perl_at_uscore_in_scalar_context \
@@ -102,6 +103,13 @@ sc_sanity_gnu_grep:
 .PHONY: sc_sanity_gnu_grep
 $(syntax_check_rules): sc_sanity_gnu_grep
 
+# Check that every subroutine in perl scripts has a corresponding
+# prototype
+sc_perl_protos:
+	$(AM_V_GEN)$(srcdir)/maintainer/check-perl-protos \
+	  <$(srcdir)/bin/aclocal.in && \
+	$(srcdir)/maintainer/check-perl-protos <$(srcdir)/bin/automake.in
+
 # These check avoids accidental configure substitutions in the source.
 # There are exactly 8 lines that should be modified from automake.in to
 # automake, and 9 lines that should be modified from aclocal.in to