Merge branch 'ab/simplify-perl-makefile'

The build procedure for perl/ part has been greatly simplified by
weaning ourselves off of MakeMaker.

* ab/simplify-perl-makefile:
  perl: treat PERLLIB_EXTRA as an extra path again
  perl: avoid *.pmc and fix Error.pm further
  Makefile: replace perl/Makefile.PL with simple make rules

14 files changed, 106 insertions, 198 deletions

diff --git a/INSTALL b/INSTALL
index ffb071e9f0..808e07b659 100644
--- a/INSTALL
+++ b/INSTALL
@@ -84,9 +84,24 @@ Issues of note:
 
 	GIT_EXEC_PATH=`pwd`
 	PATH=`pwd`:$PATH
-	GITPERLLIB=`pwd`/perl/blib/lib
+	GITPERLLIB=`pwd`/perl/build/lib
 	export GIT_EXEC_PATH PATH GITPERLLIB
 
+ - By default (unless NO_PERL is provided) Git will ship various perl
+   scripts & libraries it needs. However, for simplicity it doesn't
+   use the ExtUtils::MakeMaker toolchain to decide where to place the
+   perl libraries. Depending on the system this can result in the perl
+   libraries not being where you'd like them if they're expected to be
+   used by things other than Git itself.
+
+   Manually supplying a perllibdir prefix should fix this, if this is
+   a problem you care about, e.g.:
+
+       prefix=/usr perllibdir=/usr/$(/usr/bin/perl -MConfig -wle 'print substr $Config{installsitelib}, 1 + length $Config{siteprefixexp}')
+
+   Will result in e.g. perllibdir=/usr/share/perl/5.26.1 on Debian,
+   perllibdir=/usr/share/perl5 (which we'd use by default) on CentOS.
+
  - Git is reasonably self-sufficient, but does depend on a few external
    programs and libraries.  Git can be used without most of them by adding
    the approriate "NO_<LIBRARY>=YesPlease" to the make command line or
diff --git a/Makefile b/Makefile
index 1a9b23b679..37e02cec1b 100644
--- a/Makefile
+++ b/Makefile
@@ -294,9 +294,6 @@ all::
 #
 # Define PERL_PATH to the path of your Perl binary (usually /usr/bin/perl).
 #
-# Define NO_PERL_MAKEMAKER if you cannot use Makefiles generated by perl's
-# MakeMaker (e.g. using ActiveState under Cygwin).
-#
 # Define NO_PERL if you do not want Perl scripts or libraries at all.
 #
 # Define PYTHON_PATH to the path of your Python binary (often /usr/bin/python
@@ -479,6 +476,7 @@ gitexecdir = libexec/git-core
 mergetoolsdir = $(gitexecdir)/mergetools
 sharedir = $(prefix)/share
 gitwebdir = $(sharedir)/gitweb
+perllibdir = $(sharedir)/perl5
 localedir = $(sharedir)/locale
 template_dir = share/git-core/templates
 htmldir = $(prefix)/share/doc/git-doc
@@ -492,7 +490,7 @@ mandir_relative = $(patsubst $(prefix)/%,%,$(mandir))
 infodir_relative = $(patsubst $(prefix)/%,%,$(infodir))
 htmldir_relative = $(patsubst $(prefix)/%,%,$(htmldir))
 
-export prefix bindir sharedir sysconfdir gitwebdir localedir
+export prefix bindir sharedir sysconfdir gitwebdir perllibdir localedir
 
 CC = cc
 AR = ar
@@ -1543,9 +1541,6 @@ ifdef SHA1_MAX_BLOCK_SIZE
 	LIB_OBJS += compat/sha1-chunked.o
 	BASIC_CFLAGS += -DSHA1_MAX_BLOCK_SIZE="$(SHA1_MAX_BLOCK_SIZE)"
 endif
-ifdef NO_PERL_MAKEMAKER
-	export NO_PERL_MAKEMAKER
-endif
 ifdef NO_HSTRERROR
 	COMPAT_CFLAGS += -DNO_HSTRERROR
 	COMPAT_OBJS += compat/hstrerror.o
@@ -1732,8 +1727,10 @@ ETC_GITATTRIBUTES_SQ = $(subst ','\'',$(ETC_GITATTRIBUTES))
 DESTDIR_SQ = $(subst ','\'',$(DESTDIR))
 bindir_SQ = $(subst ','\'',$(bindir))
 bindir_relative_SQ = $(subst ','\'',$(bindir_relative))
+mandir_SQ = $(subst ','\'',$(mandir))
 mandir_relative_SQ = $(subst ','\'',$(mandir_relative))
 infodir_relative_SQ = $(subst ','\'',$(infodir_relative))
+perllibdir_SQ = $(subst ','\'',$(perllibdir))
 localedir_SQ = $(subst ','\'',$(localedir))
 gitexecdir_SQ = $(subst ','\'',$(gitexecdir))
 template_dir_SQ = $(subst ','\'',$(template_dir))
@@ -1844,9 +1841,6 @@ ifndef NO_TCLTK
 	$(QUIET_SUBDIR0)git-gui $(QUIET_SUBDIR1) gitexecdir='$(gitexec_instdir_SQ)' all
 	$(QUIET_SUBDIR0)gitk-git $(QUIET_SUBDIR1) all
 endif
-ifndef NO_PERL
-	$(QUIET_SUBDIR0)perl $(QUIET_SUBDIR1) PERL_PATH='$(PERL_PATH_SQ)' prefix='$(prefix_SQ)' localedir='$(localedir_SQ)' all
-endif
 	$(QUIET_SUBDIR0)templates $(QUIET_SUBDIR1) SHELL_PATH='$(SHELL_PATH_SQ)' PERL_PATH='$(PERL_PATH_SQ)'
 
 please_set_SHELL_PATH_to_a_more_modern_shell:
@@ -1928,7 +1922,8 @@ common-cmds.h: $(wildcard Documentation/git-*.txt)
 
 SCRIPT_DEFINES = $(SHELL_PATH_SQ):$(DIFF_SQ):$(GIT_VERSION):\
 	$(localedir_SQ):$(NO_CURL):$(USE_GETTEXT_SCHEME):$(SANE_TOOL_PATH_SQ):\
-	$(gitwebdir_SQ):$(PERL_PATH_SQ):$(SANE_TEXT_GREP):$(PAGER_ENV)
+	$(gitwebdir_SQ):$(PERL_PATH_SQ):$(SANE_TEXT_GREP):$(PAGER_ENV):\
+	$(perllibdir_SQ)
 define cmd_munge_script
 $(RM) $@ $@+ && \
 sed -e '1s|#!.*/sh|#!$(SHELL_PATH_SQ)|' \
@@ -1972,23 +1967,12 @@ git.res: git.rc GIT-VERSION-FILE
 $(SCRIPT_PERL_GEN): GIT-BUILD-OPTIONS
 
 ifndef NO_PERL
-$(SCRIPT_PERL_GEN): perl/perl.mak
-
-perl/perl.mak: perl/PM.stamp
-
-perl/PM.stamp: FORCE
-	@$(FIND) perl -type f -name '*.pm' | sort >$@+ && \
-	$(PERL_PATH) -V >>$@+ && \
-	{ cmp $@+ $@ >/dev/null 2>/dev/null || mv $@+ $@; } && \
-	$(RM) $@+
-
-perl/perl.mak: GIT-CFLAGS GIT-PREFIX perl/Makefile perl/Makefile.PL
-	$(QUIET_SUBDIR0)perl $(QUIET_SUBDIR1) PERL_PATH='$(PERL_PATH_SQ)' prefix='$(prefix_SQ)' $(@F)
+$(SCRIPT_PERL_GEN):
 
-PERL_DEFINES = $(PERL_PATH_SQ):$(PERLLIB_EXTRA_SQ)
-$(SCRIPT_PERL_GEN): % : %.perl perl/perl.mak GIT-PERL-DEFINES GIT-VERSION-FILE
+PERL_DEFINES = $(PERL_PATH_SQ):$(PERLLIB_EXTRA_SQ):$(perllibdir_SQ)
+$(SCRIPT_PERL_GEN): % : %.perl GIT-PERL-DEFINES GIT-VERSION-FILE
 	$(QUIET_GEN)$(RM) $@ $@+ && \
-	INSTLIBDIR=`MAKEFLAGS= $(MAKE) -C perl -s --no-print-directory instlibdir` && \
+	INSTLIBDIR='$(perllibdir_SQ)' && \
 	INSTLIBDIR_EXTRA='$(PERLLIB_EXTRA_SQ)' && \
 	INSTLIBDIR="$$INSTLIBDIR$${INSTLIBDIR_EXTRA:+:$$INSTLIBDIR_EXTRA}" && \
 	sed -e '1{' \
@@ -2312,6 +2296,21 @@ endif
 po/build/locale/%/LC_MESSAGES/git.mo: po/%.po
 	$(QUIET_MSGFMT)mkdir -p $(dir $@) && $(MSGFMT) -o $@ $<
 
+LIB_PERL := $(wildcard perl/Git.pm perl/Git/*.pm perl/Git/*/*.pm perl/Git/*/*/*.pm)
+LIB_PERL_GEN := $(patsubst perl/%.pm,perl/build/lib/%.pm,$(LIB_PERL))
+
+ifndef NO_PERL
+all:: $(LIB_PERL_GEN)
+endif
+
+perl/build/lib/%.pm: perl/%.pm
+	$(QUIET_GEN)mkdir -p $(dir $@) && \
+	sed -e 's|@@LOCALEDIR@@|$(localedir_SQ)|g' < $< > $@
+
+perl/build/man/man3/Git.3pm: perl/Git.pm
+	$(QUIET_GEN)mkdir -p $(dir $@) && \
+	pod2man $< $@
+
 FIND_SOURCE_FILES = ( \
 	git ls-files \
 		'*.[hcS]' \
@@ -2572,7 +2571,9 @@ ifndef NO_GETTEXT
 	(cd '$(DESTDIR_SQ)$(localedir_SQ)' && umask 022 && $(TAR) xof -)
 endif
 ifndef NO_PERL
-	$(MAKE) -C perl prefix='$(prefix_SQ)' DESTDIR='$(DESTDIR_SQ)' install
+	$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(perllibdir_SQ)'
+	(cd perl/build/lib && $(TAR) cf - .) | \
+	(cd '$(DESTDIR_SQ)$(perllibdir_SQ)' && umask 022 && $(TAR) xof -)
 	$(MAKE) -C gitweb install
 endif
 ifndef NO_TCLTK
@@ -2622,12 +2623,17 @@ endif
 install-gitweb:
 	$(MAKE) -C gitweb install
 
-install-doc:
+install-doc: install-man-perl
 	$(MAKE) -C Documentation install
 
-install-man:
+install-man: install-man-perl
 	$(MAKE) -C Documentation install-man
 
+install-man-perl: perl/build/man/man3/Git.3pm
+	$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(mandir_SQ)/man3'
+	(cd perl/build/man/man3 && $(TAR) cf - .) | \
+	(cd '$(DESTDIR_SQ)$(mandir_SQ)/man3' && umask 022 && $(TAR) xof -)
+
 install-html:
 	$(MAKE) -C Documentation install-html
 
@@ -2719,7 +2725,7 @@ clean: profile-clean coverage-clean
 	$(MAKE) -C Documentation/ clean
 ifndef NO_PERL
 	$(MAKE) -C gitweb clean
-	$(MAKE) -C perl clean
+	$(RM) -r perl/build/
 endif
 	$(MAKE) -C templates/ clean
 	$(MAKE) -C t/ clean
diff --git a/contrib/examples/git-difftool.perl b/contrib/examples/git-difftool.perl
index df59bdfe97..fb0fd0b84b 100755
--- a/contrib/examples/git-difftool.perl
+++ b/contrib/examples/git-difftool.perl
@@ -13,7 +13,7 @@
 use 5.008;
 use strict;
 use warnings;
-use Error qw(:try);
+use Git::Error qw(:try);
 use File::Basename qw(dirname);
 use File::Copy;
 use File::Find;
diff --git a/git-send-email.perl b/git-send-email.perl
index 340b5c8482..bbf4deaa0d 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -26,7 +26,7 @@ use Text::ParseWords;
 use Term::ANSIColor;
 use File::Temp qw/ tempdir tempfile /;
 use File::Spec::Functions qw(catdir catfile);
-use Error qw(:try);
+use Git::Error qw(:try);
 use Cwd qw(abs_path cwd);
 use Git;
 use Git::I18N;
diff --git a/perl/.gitignore b/perl/.gitignore
index 0f1fc27f86..84c048a73c 100644
--- a/perl/.gitignore
+++ b/perl/.gitignore
@@ -1,8 +1 @@
-perl.mak
-perl.mak.old
-MYMETA.json
-MYMETA.yml
-blib
-blibdirs
-pm_to_blib
-PM.stamp
+/build/
diff --git a/perl/Git.pm b/perl/Git.pm
index 65e6b32a0f..9d60d7948b 100644
--- a/perl/Git.pm
+++ b/perl/Git.pm
@@ -101,7 +101,7 @@ increase notwithstanding).
 
 
 use Carp qw(carp croak); # but croak is bad - throw instead
-use Error qw(:try);
+use Git::Error qw(:try);
 use Cwd qw(abs_path cwd);
 use IPC::Open2 qw(open2);
 use Fcntl qw(SEEK_SET SEEK_CUR);
diff --git a/perl/Git/Error.pm b/perl/Git/Error.pm
new file mode 100644
index 0000000000..09bbc97390
--- /dev/null
+++ b/perl/Git/Error.pm
@@ -0,0 +1,46 @@
+package Git::Error;
+use 5.008;
+use strict;
+use warnings;
+
+=head1 NAME
+
+Git::Error - Wrapper for the L<Error> module, in case it's not installed
+
+=head1 DESCRIPTION
+
+Wraps the import function for the L<Error> module.
+
+This module is only intended to be used for code shipping in the
+C<git.git> repository. Use it for anything else at your peril!
+
+=cut
+
+sub import {
+    shift;
+    my $caller = caller;
+
+    eval {
+	require Error;
+	1;
+    } or do {
+	my $error = $@ || "Zombie Error";
+
+	my $Git_Error_pm_path = $INC{"Git/Error.pm"} || die "BUG: Should have our own path from %INC!";
+
+	require File::Basename;
+	my $Git_Error_pm_root = File::Basename::dirname($Git_Error_pm_path) || die "BUG: Can't figure out lib/Git dirname from '$Git_Error_pm_path'!";
+
+	require File::Spec;
+	my $Git_pm_FromCPAN_root = File::Spec->catdir($Git_Error_pm_root, 'FromCPAN');
+	die "BUG: '$Git_pm_FromCPAN_root' should be a directory!" unless -d $Git_pm_FromCPAN_root;
+
+	local @INC = ($Git_pm_FromCPAN_root, @INC);
+	require Error;
+    };
+
+    unshift @_, $caller;
+    goto &Error::import;
+}
+
+1;
diff --git a/perl/private-Error.pm b/perl/Git/FromCPAN/Error.pm
index 6098135ae2..6098135ae2 100644
--- a/perl/private-Error.pm
+++ b/perl/Git/FromCPAN/Error.pm
diff --git a/perl/Git/I18N.pm b/perl/Git/I18N.pm
index 836a5c2382..dba96fff0a 100644
--- a/perl/Git/I18N.pm
+++ b/perl/Git/I18N.pm
@@ -18,7 +18,7 @@ our @EXPORT_OK = @EXPORT;
 
 sub __bootstrap_locale_messages {
 	our $TEXTDOMAIN = 'git';
-	our $TEXTDOMAINDIR = $ENV{GIT_TEXTDOMAINDIR} || '++LOCALEDIR++';
+	our $TEXTDOMAINDIR = $ENV{GIT_TEXTDOMAINDIR} || '@@LOCALEDIR@@';
 
 	require POSIX;
 	POSIX->import(qw(setlocale));
diff --git a/perl/Makefile b/perl/Makefile
deleted file mode 100644
index f657de20e3..0000000000
--- a/perl/Makefile
+++ /dev/null
@@ -1,90 +0,0 @@
-#
-# Makefile for perl support modules and routine
-#
-makfile:=perl.mak
-modules =
-
-PERL_PATH_SQ = $(subst ','\'',$(PERL_PATH))
-prefix_SQ = $(subst ','\'',$(prefix))
-localedir_SQ = $(subst ','\'',$(localedir))
-
-ifndef V
-	QUIET = @
-endif
-
-all install instlibdir: $(makfile)
-	$(QUIET)$(MAKE) -f $(makfile) $@
-
-clean:
-	$(QUIET)test -f $(makfile) && $(MAKE) -f $(makfile) $@ || exit 0
-	$(RM) ppport.h
-	$(RM) $(makfile)
-	$(RM) $(makfile).old
-	$(RM) PM.stamp
-
-$(makfile): PM.stamp
-
-ifdef NO_PERL_MAKEMAKER
-instdir_SQ = $(subst ','\'',$(prefix)/lib)
-
-modules += Git
-modules += Git/I18N
-modules += Git/IndexInfo
-modules += Git/Packet
-modules += Git/SVN
-modules += Git/SVN/Memoize/YAML
-modules += Git/SVN/Fetcher
-modules += Git/SVN/Editor
-modules += Git/SVN/GlobSpec
-modules += Git/SVN/Log
-modules += Git/SVN/Migration
-modules += Git/SVN/Prompt
-modules += Git/SVN/Ra
-modules += Git/SVN/Utils
-
-$(makfile): ../GIT-CFLAGS Makefile
-	echo all: private-Error.pm Git.pm Git/I18N.pm > $@
-	set -e; \
-	for i in $(modules); \
-	do \
-		if test $$i = $${i%/*}; \
-		then \
-			subdir=; \
-		else \
-			subdir=/$${i%/*}; \
-		fi; \
-		echo '	$(RM) blib/lib/'$$i'.pm' >> $@; \
-		echo '	mkdir -p blib/lib'$$subdir >> $@; \
-		echo '	cp '$$i'.pm blib/lib/'$$i'.pm' >> $@; \
-	done
-	echo '	$(RM) blib/lib/Error.pm' >> $@
-	'$(PERL_PATH_SQ)' -MError -e 'exit($$Error::VERSION < 0.15009)' || \
-	echo '	cp private-Error.pm blib/lib/Error.pm' >> $@
-	echo install: >> $@
-	set -e; \
-	for i in $(modules); \
-	do \
-		if test $$i = $${i%/*}; \
-		then \
-			subdir=; \
-		else \
-			subdir=/$${i%/*}; \
-		fi; \
-		echo '	$(RM) "$$(DESTDIR)$(instdir_SQ)/'$$i'.pm"' >> $@; \
-		echo '	mkdir -p "$$(DESTDIR)$(instdir_SQ)'$$subdir'"' >> $@; \
-		echo '	cp '$$i'.pm "$$(DESTDIR)$(instdir_SQ)/'$$i'.pm"' >> $@; \
-	done
-	echo '	$(RM) "$$(DESTDIR)$(instdir_SQ)/Error.pm"' >> $@
-	'$(PERL_PATH_SQ)' -MError -e 'exit($$Error::VERSION < 0.15009)' || \
-	echo '	cp private-Error.pm "$$(DESTDIR)$(instdir_SQ)/Error.pm"' >> $@
-	echo instlibdir: >> $@
-	echo '	echo $(instdir_SQ)' >> $@
-else
-$(makfile): Makefile.PL ../GIT-CFLAGS
-	$(PERL_PATH) $< PREFIX='$(prefix_SQ)' INSTALL_BASE='' --localedir='$(localedir_SQ)'
-endif
-
-# this is just added comfort for calling make directly in perl dir
-# (even though GIT-CFLAGS aren't used yet. If ever)
-../GIT-CFLAGS:
-	$(MAKE) -C .. GIT-CFLAGS
diff --git a/perl/Makefile.PL b/perl/Makefile.PL
deleted file mode 100644
index 3f29ba98a6..0000000000
--- a/perl/Makefile.PL
+++ /dev/null
@@ -1,62 +0,0 @@
-use strict;
-use warnings;
-use ExtUtils::MakeMaker;
-use Getopt::Long;
-use File::Find;
-
-# Don't forget to update the perl/Makefile, too.
-# Don't forget to test with NO_PERL_MAKEMAKER=YesPlease
-
-# Sanity: die at first unknown option
-Getopt::Long::Configure qw/ pass_through /;
-
-my $localedir = '';
-GetOptions("localedir=s" => \$localedir);
-
-sub MY::postamble {
-	return <<'MAKE_FRAG';
-instlibdir:
-	@echo '$(INSTALLSITELIB)'
-
-ifneq (,$(DESTDIR))
-ifeq (0,$(shell expr '$(MM_VERSION)' '>' 6.10))
-$(error ExtUtils::MakeMaker version "$(MM_VERSION)" is older than 6.11 and so \
-	is likely incompatible with the DESTDIR mechanism.  Try setting \
-	NO_PERL_MAKEMAKER=1 instead)
-endif
-endif
-
-MAKE_FRAG
-}
-
-# Find all the .pm files in "Git/" and Git.pm
-my %pm;
-find sub {
-	return unless /\.pm$/;
-
-	# sometimes File::Find prepends a ./  Strip it.
-	my $pm_path = $File::Find::name;
-	$pm_path =~ s{^\./}{};
-
-	$pm{$pm_path} = '$(INST_LIBDIR)/'.$pm_path;
-}, "Git", "Git.pm";
-
-
-# We come with our own bundled Error.pm. It's not in the set of default
-# Perl modules so install it if it's not available on the system yet.
-if ( !eval { require Error } || $Error::VERSION < 0.15009) {
-	$pm{'private-Error.pm'} = '$(INST_LIBDIR)/Error.pm';
-}
-
-# redirect stdout, otherwise the message "Writing perl.mak for Git"
-# disrupts the output for the target 'instlibdir'
-open STDOUT, ">&STDERR";
-
-WriteMakefile(
-	NAME            => 'Git',
-	VERSION_FROM    => 'Git.pm',
-	PM		=> \%pm,
-	PM_FILTER	=> qq[\$(PERL) -pe "s<\\Q++LOCALEDIR++\\E><$localedir>"],
-	MAKEFILE	=> 'perl.mak',
-	INSTALLSITEMAN3DIR => '$(SITEPREFIX)/share/man/man3'
-);
diff --git a/t/perf/aggregate.perl b/t/perf/aggregate.perl
index 5c439f6bc2..3a0917fa61 100755
--- a/t/perf/aggregate.perl
+++ b/t/perf/aggregate.perl
@@ -1,6 +1,6 @@
 #!/usr/bin/perl
 
-use lib '../../perl/blib/lib';
+use lib '../../perl/build/lib';
 use strict;
 use warnings;
 use JSON;
diff --git a/t/test-lib.sh b/t/test-lib.sh
index 9a0a21f49a..9af19055b3 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -939,7 +939,7 @@ then
 	fi
 fi
 
-GITPERLLIB="$GIT_BUILD_DIR"/perl/blib/lib:"$GIT_BUILD_DIR"/perl/blib/arch/auto/Git
+GITPERLLIB="$GIT_BUILD_DIR"/perl/build/lib
 export GITPERLLIB
 test -d "$GIT_BUILD_DIR"/templates/blt || {
 	error "You haven't built things yet, have you?"
diff --git a/wrap-for-bin.sh b/wrap-for-bin.sh
index 22b6e4948f..5842408817 100644
--- a/wrap-for-bin.sh
+++ b/wrap-for-bin.sh
@@ -14,7 +14,7 @@ else
 	GIT_TEMPLATE_DIR='@@BUILD_DIR@@/templates/blt'
 	export GIT_TEMPLATE_DIR
 fi
-GITPERLLIB='@@BUILD_DIR@@/perl/blib/lib'"${GITPERLLIB:+:$GITPERLLIB}"
+GITPERLLIB='@@BUILD_DIR@@/perl/build/lib'"${GITPERLLIB:+:$GITPERLLIB}"
 GIT_TEXTDOMAINDIR='@@BUILD_DIR@@/po/build/locale'
 PATH='@@BUILD_DIR@@/bin-wrappers:'"$PATH"