[PATCH 1/4] Makefile: extract perl-related rules to make them available from other dirs

[Matthieu Moy <Matthieu.Moy@imag.fr>]

The final goal is to make it easy to write Git commands in perl in the
contrib/ directory. It is currently possible to do so, but without the
benefits of Git's Makefile: adapt first line with $(PERL_PATH),
hardcode the path to Git.pm, ...

We make the perl-related part of the Makefile available from directories
other than the toplevel so that:

* Developers can include it, to avoid code duplication

* Users can get a consistent behavior of "make install"

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
---
 Makefile | 46 +---------------------------------------------
 perl.mak | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+), 45 deletions(-)
 create mode 100644 perl.mak

diff --git a/Makefile b/Makefile
index 731b6a8..f39d4a9 100644
--- a/Makefile
+++ b/Makefile
@@ -573,14 +573,10 @@ BINDIR_PROGRAMS_NO_X += git-cvsserver
 ifndef SHELL_PATH
 	SHELL_PATH = /bin/sh
 endif
-ifndef PERL_PATH
-	PERL_PATH = /usr/bin/perl
-endif
 ifndef PYTHON_PATH
 	PYTHON_PATH = /usr/bin/python
 endif
 
-export PERL_PATH
 export PYTHON_PATH
 
 LIB_FILE = libgit.a
@@ -1441,10 +1437,6 @@ ifeq ($(TCLTK_PATH),)
 NO_TCLTK = NoThanks
 endif
 
-ifeq ($(PERL_PATH),)
-NO_PERL = NoThanks
-endif
-
 ifeq ($(PYTHON_PATH),)
 NO_PYTHON = NoThanks
 endif
@@ -1522,7 +1514,6 @@ prefix_SQ = $(subst ','\'',$(prefix))
 gitwebdir_SQ = $(subst ','\'',$(gitwebdir))
 
 SHELL_PATH_SQ = $(subst ','\'',$(SHELL_PATH))
-PERL_PATH_SQ = $(subst ','\'',$(PERL_PATH))
 PYTHON_PATH_SQ = $(subst ','\'',$(PYTHON_PATH))
 TCLTK_PATH_SQ = $(subst ','\'',$(TCLTK_PATH))
 DIFF_SQ = $(subst ','\'',$(DIFF))
@@ -1715,9 +1706,6 @@ $(SCRIPT_LIB) : % : %.sh GIT-SCRIPT-DEFINES
 	$(QUIET_GEN)$(cmd_munge_script) && \
 	mv $@+ $@
 
-ifndef NO_PERL
-$(patsubst %.perl,%,$(SCRIPT_PERL)): perl/perl.mak
-
 perl/perl.mak: perl/PM.stamp
 
 perl/PM.stamp: FORCE
@@ -1728,39 +1716,7 @@ perl/PM.stamp: FORCE
 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)
 
-$(patsubst %.perl,%,$(SCRIPT_PERL)): % : %.perl GIT-VERSION-FILE
-	$(QUIET_GEN)$(RM) $@ $@+ && \
-	INSTLIBDIR=`MAKEFLAGS= $(MAKE) -C perl -s --no-print-directory instlibdir` && \
-	sed -e '1{' \
-	    -e '	s|#!.*perl|#!$(PERL_PATH_SQ)|' \
-	    -e '	h' \
-	    -e '	s=.*=use lib (split(/$(pathsep)/, $$ENV{GITPERLLIB} || "'"$$INSTLIBDIR"'"));=' \
-	    -e '	H' \
-	    -e '	x' \
-	    -e '}' \
-	    -e 's/@@GIT_VERSION@@/$(GIT_VERSION)/g' \
-	    $@.perl >$@+ && \
-	chmod +x $@+ && \
-	mv $@+ $@
-
-
-.PHONY: gitweb
-gitweb:
-	$(QUIET_SUBDIR0)gitweb $(QUIET_SUBDIR1) all
-
-git-instaweb: git-instaweb.sh gitweb GIT-SCRIPT-DEFINES
-	$(QUIET_GEN)$(cmd_munge_script) && \
-	chmod +x $@+ && \
-	mv $@+ $@
-else # NO_PERL
-$(patsubst %.perl,%,$(SCRIPT_PERL)) git-instaweb: % : unimplemented.sh
-	$(QUIET_GEN)$(RM) $@ $@+ && \
-	sed -e '1s|#!.*/sh|#!$(SHELL_PATH_SQ)|' \
-	    -e 's|@@REASON@@|NO_PERL=$(NO_PERL)|g' \
-	    unimplemented.sh >$@+ && \
-	chmod +x $@+ && \
-	mv $@+ $@
-endif # NO_PERL
+include perl.mak
 
 ifndef NO_PYTHON
 $(patsubst %.py,%,$(SCRIPT_PYTHON)): GIT-CFLAGS GIT-PREFIX GIT-PYTHON-VARS
diff --git a/perl.mak b/perl.mak
new file mode 100644
index 0000000..8bbeef3
--- /dev/null
+++ b/perl.mak
@@ -0,0 +1,49 @@
+# Rules to build Git commands written in perl
+
+ifndef PERL_PATH
+	PERL_PATH = /usr/bin/perl
+endif
+export PERL_PATH
+PERL_PATH_SQ = $(subst ','\'',$(PERL_PATH))
+
+ifeq ($(PERL_PATH),)
+NO_PERL = NoThanks
+endif
+
+ifndef NO_PERL
+$(patsubst %.perl,%,$(SCRIPT_PERL)): perl/perl.mak
+
+
+$(patsubst %.perl,%,$(SCRIPT_PERL)): % : %.perl GIT-VERSION-FILE
+	$(QUIET_GEN)$(RM) $@ $@+ && \
+	INSTLIBDIR=`MAKEFLAGS= $(MAKE) -C perl -s --no-print-directory instlibdir` && \
+	sed -e '1{' \
+	    -e '	s|#!.*perl|#!$(PERL_PATH_SQ)|' \
+	    -e '	h' \
+	    -e '	s=.*=use lib (split(/$(pathsep)/, $$ENV{GITPERLLIB} || "'"$$INSTLIBDIR"'"));=' \
+	    -e '	H' \
+	    -e '	x' \
+	    -e '}' \
+	    -e 's/@@GIT_VERSION@@/$(GIT_VERSION)/g' \
+	    $@.perl >$@+ && \
+	chmod +x $@+ && \
+	mv $@+ $@
+
+
+.PHONY: gitweb
+gitweb:
+	$(QUIET_SUBDIR0)gitweb $(QUIET_SUBDIR1) all
+
+git-instaweb: git-instaweb.sh gitweb GIT-SCRIPT-DEFINES
+	$(QUIET_GEN)$(cmd_munge_script) && \
+	chmod +x $@+ && \
+	mv $@+ $@
+else # NO_PERL
+$(patsubst %.perl,%,$(SCRIPT_PERL)) git-instaweb: % : unimplemented.sh
+	$(QUIET_GEN)$(RM) $@ $@+ && \
+	sed -e '1s|#!.*/sh|#!$(SHELL_PATH_SQ)|' \
+	    -e 's|@@REASON@@|NO_PERL=$(NO_PERL)|g' \
+	    unimplemented.sh >$@+ && \
+	chmod +x $@+ && \
+	mv $@+ $@
+endif # NO_PERL
-- 
1.8.1.2.526.gf51a757