# [PATCH 0/5] Makefile: add missing header dependency rules

27 messages from 2010-01-23 to 2010-01-31. Participants: Jonathan Nieder, Junio C Hamano.
Thread: https://gitlist.dev/t/22357

## Jonathan Nieder, 2010-01-23 14:42

Subject: [PATCH 0/5] Makefile: add missing header dependency rules
Message-ID: <20100123144201.GA11903@progeny.tock>
URL: https://gitlist.dev/e/20100123144201.GA11903%40progeny.tock

```
Hi,

As a side-effect of generating dependency rules during the build
locally, it is possible to sanity-check the existing hard-coded
header file dependencies. [1]  Now the original topic of that thread [2]
can be addressed without collateral damage.

That is what patches 1 and 2 do.  The remaining patches are small
clean-ups that decrease the amount of dependencies again.

These patches are independent of the jn/makefile topic.  I sent them
before, but I screwed up the sender so nobody received them.  Anyway,
perhaps they could be useful.

Jonathan Nieder (5):
  Makefile: add missing header file dependencies
  Makefile: make sure test helpers are rebuilt when headers change
  Makefile: remove wt-status.h from LIB_H
  Makefile: clean up http-walker.o dependency rules
  Makefile: drop */*.h dependency rule

 Makefile |   58 +++++++++++++++++++++++++++++++++++++---------------------
 1 files changed, 37 insertions(+), 21 deletions(-)

[1] http://thread.gmane.org/gmane.comp.version-control.git/133872/focus=136257
[2] http://thread.gmane.org/gmane.comp.version-control.git/133872/focus=133884

```

## Jonathan Nieder, 2010-01-23 14:43

Subject: [PATCH 1/5] Makefile: add missing header file dependencies
Message-ID: <20100123144320.GB11903@progeny.tock>
URL: https://gitlist.dev/e/20100123144320.GB11903%40progeny.tock
In-Reply-To: <20100123144201.GA11903@progeny.tock>

```
LIB_H is missing exec_cmd.h and color.h.  cache.h includes
SHA1_HEADER, and thus so does almost everything else, so add that
to LIB_H, too.  xdiff-interface.h is not included by any header
files, but so many source files use xdiff that it is simplest to
include it in LIB_H, too.

xdiff-interface.o uses the xdiff library heavily; let it depend
on all xdiff headers to avoid needing to keep track of which
headers it uses.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
 Makefile |   19 ++++++++++++++++++-
 1 files changed, 18 insertions(+), 1 deletions(-)

diff --git a/Makefile b/Makefile
index fd7f51e..2a408d7 100644
--- a/Makefile
+++ b/Makefile
@@ -447,6 +447,7 @@ LIB_H += blob.h
 LIB_H += builtin.h
 LIB_H += cache.h
 LIB_H += cache-tree.h
+LIB_H += color.h
 LIB_H += commit.h
 LIB_H += compat/bswap.h
 LIB_H += compat/cygwin.h
@@ -457,6 +458,7 @@ LIB_H += delta.h
 LIB_H += diffcore.h
 LIB_H += diff.h
 LIB_H += dir.h
+LIB_H += exec_cmd.h
 LIB_H += fsck.h
 LIB_H += git-compat-util.h
 LIB_H += graph.h
@@ -499,6 +501,8 @@ LIB_H += unpack-trees.h
 LIB_H += userdiff.h
 LIB_H += utf8.h
 LIB_H += wt-status.h
+LIB_H += xdiff-interface.h
+LIB_H += xdiff/xdiff.h
 
 LIB_OBJS += abspath.o
 LIB_OBJS += advice.o
@@ -1281,10 +1285,12 @@ endif
 ifdef BLK_SHA1
 	SHA1_HEADER = "block-sha1/sha1.h"
 	LIB_OBJS += block-sha1/sha1.o
+	LIB_H += block-sha1/sha1.h
 else
 ifdef PPC_SHA1
 	SHA1_HEADER = "ppc/sha1.h"
 	LIB_OBJS += ppc/sha1.o ppc/sha1ppc.o
+	LIB_H += ppc/sha1.h
 else
 	SHA1_HEADER = <openssl/sha.h>
 	EXTLIBS += $(LIB_4_CRYPTO)
@@ -1637,14 +1643,25 @@ git-remote-curl$X: remote-curl.o http.o http-walker.o $(GITLIBS)
 
 $(LIB_OBJS) $(BUILTIN_OBJS): $(LIB_H)
 $(patsubst git-%$X,%.o,$(PROGRAMS)) git.o: $(LIB_H) $(wildcard */*.h)
+builtin-branch.o builtin-checkout.o builtin-clone.o builtin-reset.o branch.o: branch.h
+builtin-bundle.o bundle.o transport.o: bundle.h
+builtin-bisect--helper.o builtin-rev-list.o bisect.o: bisect.h
+builtin-clone.o builtin-fetch-pack.o transport.o: fetch-pack.h
+builtin-send-pack.o transport.o: send-pack.h
+builtin-log.o builtin-shortlog.o: shortlog.h
 builtin-revert.o wt-status.o: wt-status.h
+builtin-prune.o builtin-reflog.o reachable.o: reachable.h
+builtin-tar-tree.o archive-tar.o: tar.h
+builtin-pack-objects.o: thread-utils.h
+http-fetch.o http-walker.o remote-curl.o transport.o walker.o: walker.h
 
 $(LIB_FILE): $(LIB_OBJS)
 	$(QUIET_AR)$(RM) $@ && $(AR) rcs $@ $(LIB_OBJS)
 
 XDIFF_OBJS=xdiff/xdiffi.o xdiff/xprepare.o xdiff/xutils.o xdiff/xemit.o \
 	xdiff/xmerge.o xdiff/xpatience.o
-$(XDIFF_OBJS): xdiff/xinclude.h xdiff/xmacros.h xdiff/xdiff.h xdiff/xtypes.h \
+xdiff-interface.o $(XDIFF_OBJS): xdiff/xinclude.h \
+	xdiff/xmacros.h xdiff/xdiff.h xdiff/xtypes.h \
 	xdiff/xutils.h xdiff/xprepare.h xdiff/xdiffi.h xdiff/xemit.h
 
 $(XDIFF_LIB): $(XDIFF_OBJS)
-- 
1.6.6.rc2

```

## Jonathan Nieder, 2010-01-23 14:44

Subject: [PATCH 2/5] Makefile: make sure test helpers are rebuilt when headers change
Message-ID: <20100123144415.GC11903@progeny.tock>
URL: https://gitlist.dev/e/20100123144415.GC11903%40progeny.tock
In-Reply-To: <20100123144201.GA11903@progeny.tock>

```
It is not worth the bother to maintain an up-to-date list of
which headers each test helper uses, so depend on $(LIB_H) to
catch them all.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
Verified (a few weeks ago) with 'make CHECK_HEADER_DEPENDENCIES=1'.

 Makefile |   32 ++++++++++++++++----------------
 1 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/Makefile b/Makefile
index 2a408d7..448d552 100644
--- a/Makefile
+++ b/Makefile
@@ -384,6 +384,18 @@ SCRIPTS = $(patsubst %.sh,%,$(SCRIPT_SH)) \
 # Empty...
 EXTRA_PROGRAMS =
 
+TEST_PROGRAMS += test-chmtime$X
+TEST_PROGRAMS += test-ctype$X
+TEST_PROGRAMS += test-date$X
+TEST_PROGRAMS += test-delta$X
+TEST_PROGRAMS += test-dump-cache-tree$X
+TEST_PROGRAMS += test-genrandom$X
+TEST_PROGRAMS += test-match-trees$X
+TEST_PROGRAMS += test-parse-options$X
+TEST_PROGRAMS += test-path-utils$X
+TEST_PROGRAMS += test-sha1$X
+TEST_PROGRAMS += test-sigchain$X
+
 # ... and all the rest that could be moved out of bindir to gitexecdir
 PROGRAMS += $(EXTRA_PROGRAMS)
 PROGRAMS += git-fast-import$X
@@ -695,6 +707,8 @@ BUILTIN_OBJS += builtin-verify-pack.o
 BUILTIN_OBJS += builtin-verify-tag.o
 BUILTIN_OBJS += builtin-write-tree.o
 
+TEST_OBJS := $(patsubst test-%$X,test-%.o,$(TEST_PROGRAMS))
+
 GITLIBS = $(LIB_FILE) $(XDIFF_LIB)
 EXTLIBS =
 
@@ -1641,7 +1655,7 @@ git-remote-curl$X: remote-curl.o http.o http-walker.o $(GITLIBS)
 	$(QUIET_LINK)$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) \
 		$(LIBS) $(CURL_LIBCURL) $(EXPAT_LIBEXPAT)
 
-$(LIB_OBJS) $(BUILTIN_OBJS): $(LIB_H)
+$(LIB_OBJS) $(BUILTIN_OBJS) $(TEST_OBJS): $(LIB_H)
 $(patsubst git-%$X,%.o,$(PROGRAMS)) git.o: $(LIB_H) $(wildcard */*.h)
 builtin-branch.o builtin-checkout.o builtin-clone.o builtin-reset.o branch.o: branch.h
 builtin-bundle.o bundle.o transport.o: bundle.h
@@ -1732,18 +1746,6 @@ endif
 
 ### Testing rules
 
-TEST_PROGRAMS += test-chmtime$X
-TEST_PROGRAMS += test-ctype$X
-TEST_PROGRAMS += test-date$X
-TEST_PROGRAMS += test-delta$X
-TEST_PROGRAMS += test-dump-cache-tree$X
-TEST_PROGRAMS += test-genrandom$X
-TEST_PROGRAMS += test-match-trees$X
-TEST_PROGRAMS += test-parse-options$X
-TEST_PROGRAMS += test-path-utils$X
-TEST_PROGRAMS += test-sha1$X
-TEST_PROGRAMS += test-sigchain$X
-
 all:: $(TEST_PROGRAMS)
 
 # GNU make supports exporting all variables by "export" without parameters.
@@ -1763,9 +1765,7 @@ test-delta$X: diff-delta.o patch-delta.o
 
 test-parse-options$X: parse-options.o
 
-test-parse-options.o: parse-options.h
-
-.PRECIOUS: $(patsubst test-%$X,test-%.o,$(TEST_PROGRAMS))
+.PRECIOUS: $(TEST_OBJS)
 
 test-%$X: test-%.o $(GITLIBS)
 	$(QUIET_LINK)$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) $(LIBS)
-- 
1.6.6.rc2

```

## Jonathan Nieder, 2010-01-23 14:44

Subject: [PATCH 3/5] Makefile: remove wt-status.h from LIB_H
Message-ID: <20100123144448.GD11903@progeny.tock>
URL: https://gitlist.dev/e/20100123144448.GD11903%40progeny.tock
In-Reply-To: <20100123144201.GA11903@progeny.tock>

```
A list of the few translation units using this header is
half-populated already.  Including the dependency on this header
twice (once explicitly, once through LIB_H) makes it difficult to
figure out where future headers should be added to the Makefile.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
I imagine the 'status' output is not used widely enough to consider it
a library header yet, but I could be easily convinced otherwise.
More important is to avoid the confusing double-dependency.

 Makefile |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index 448d552..7da52a3 100644
--- a/Makefile
+++ b/Makefile
@@ -512,7 +512,6 @@ LIB_H += tree-walk.h
 LIB_H += unpack-trees.h
 LIB_H += userdiff.h
 LIB_H += utf8.h
-LIB_H += wt-status.h
 LIB_H += xdiff-interface.h
 LIB_H += xdiff/xdiff.h
 
@@ -1663,7 +1662,7 @@ builtin-bisect--helper.o builtin-rev-list.o bisect.o: bisect.h
 builtin-clone.o builtin-fetch-pack.o transport.o: fetch-pack.h
 builtin-send-pack.o transport.o: send-pack.h
 builtin-log.o builtin-shortlog.o: shortlog.h
-builtin-revert.o wt-status.o: wt-status.h
+builtin-commit.o builtin-revert.o wt-status.o: wt-status.h
 builtin-prune.o builtin-reflog.o reachable.o: reachable.h
 builtin-tar-tree.o archive-tar.o: tar.h
 builtin-pack-objects.o: thread-utils.h
-- 
1.6.6.rc2

```

## Jonathan Nieder, 2010-01-23 14:45

Subject: [PATCH 4/5] Makefile: clean up http-walker.o dependency rules
Message-ID: <20100123144510.GE11903@progeny.tock>
URL: https://gitlist.dev/e/20100123144510.GE11903%40progeny.tock
In-Reply-To: <20100123144201.GA11903@progeny.tock>

```
http-walker.o depends on http.h twice: once in the rule listing
files that use http.h, and again in the rule explaining how to
build it.  Messy.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
 Makefile |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/Makefile b/Makefile
index 7da52a3..eb225c6 100644
--- a/Makefile
+++ b/Makefile
@@ -1628,7 +1628,7 @@ http.o: http.c GIT-CFLAGS
 	$(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) -DGIT_USER_AGENT='"git/$(GIT_VERSION)"' $<
 
 ifdef NO_EXPAT
-http-walker.o: http-walker.c http.h GIT-CFLAGS
+http-walker.o: http-walker.c GIT-CFLAGS
 	$(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) -DNO_EXPAT $<
 endif
 
-- 
1.6.6.rc2

```

## Jonathan Nieder, 2010-01-23 14:45

Subject: [PATCH 5/5] Makefile: drop dependency on $(wildcard */*.h)
Message-ID: <20100123144552.GF11903@progeny.tock>
URL: https://gitlist.dev/e/20100123144552.GF11903%40progeny.tock
In-Reply-To: <20100123144201.GA11903@progeny.tock>

```
The files this pulls in are already pulled in by other dependency
rules (some recently added).

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
 Makefile |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/Makefile b/Makefile
index eb225c6..d6ebc9d 100644
--- a/Makefile
+++ b/Makefile
@@ -1655,7 +1655,7 @@ git-remote-curl$X: remote-curl.o http.o http-walker.o $(GITLIBS)
 		$(LIBS) $(CURL_LIBCURL) $(EXPAT_LIBEXPAT)
 
 $(LIB_OBJS) $(BUILTIN_OBJS) $(TEST_OBJS): $(LIB_H)
-$(patsubst git-%$X,%.o,$(PROGRAMS)) git.o: $(LIB_H) $(wildcard */*.h)
+$(patsubst git-%$X,%.o,$(PROGRAMS)) git.o: $(LIB_H)
 builtin-branch.o builtin-checkout.o builtin-clone.o builtin-reset.o branch.o: branch.h
 builtin-bundle.o bundle.o transport.o: bundle.h
 builtin-bisect--helper.o builtin-rev-list.o bisect.o: bisect.h
-- 
1.6.6.rc2

```

## Junio C Hamano, 2010-01-25 04:44

Subject: Re: [PATCH 0/5] Makefile: add missing header dependency rules
Message-ID: <7v3a1u6bfz.fsf@alter.siamese.dyndns.org>
URL: https://gitlist.dev/e/7v3a1u6bfz.fsf%40alter.siamese.dyndns.org
In-Reply-To: <20100123144201.GA11903@progeny.tock>

```
Jonathan Nieder <jrnieder@gmail.com> writes:
> These patches are independent of the jn/makefile topic.  I sent them
> before, but I screwed up the sender so nobody received them.  Anyway,
> perhaps they could be useful.

I found all of them sensible but it seems to be based on version that is a
bit behind...

```

## Jonathan Nieder, 2010-01-26 15:43

Subject: [PATCH 00/12] Re: Makefile: add missing header dependency rules
Message-ID: <20100126154357.GA4895@progeny.tock>
URL: https://gitlist.dev/e/20100126154357.GA4895%40progeny.tock
In-Reply-To: <7v3a1u6bfz.fsf@alter.siamese.dyndns.org>

```
Junio C Hamano wrote:
> Jonathan Nieder <jrnieder@gmail.com> writes:

>> These patches are independent of the jn/makefile topic.  I sent them
>> before, but I screwed up the sender so nobody received them.  Anyway,
>> perhaps they could be useful.
>
> I found all of them sensible but it seems to be based on version that is a
> bit behind...

Thanks.  Patches 1-5 below are those I sent before, rebased against
maint.  Since last time, remote-curl.o gained a few more dependencies,
which are included.

The remainder of this series is based on a merge of master and
patches 1-5:

 Patch 6 adds another missing header dependency rule.  It is not
 included with the others because it applies to master, not maint.

 Patches 7-12 revisit the topic of generating header dependency
 rules on the fly.  I updated them to produce patches 1-6, so I
 thought, why not get some feedback on their present state?

Patch 7 clumps the header dependency rules together.  I think this
makes them more readable; more importantly, later this will allow
ifdef'ing them out later in one fell swoop.

Patches 8-9 and 11 list all targets that can depend on headers in a
new OBJECTS variable, for use in patches 10 and 12.

Patch 10 generates header dependency rules on the fly.  The resulting
dependency rules contain no useless dependencies (unlike the
hard-coded ones where almost everything depends on $(LIB_H)), so this
might be interesting to people wishing to speed up the
edit-compile-run cycle.

This only works with gcc.  It should be possible to teach the relevant
options to clink.pl if there is demand, but not SCO cc.

Patch 12 is what I am most interested in: it uses the computed
dependencies to check that the hard-coded dependency rules are
correct.  In the long term, maybe we will be able to get rid of the
hard-coded header dep rules altogether; in the short term, I am hoping
this checker can be useful for avoiding problems with the hard-coded
rules without spending too much human time on it.

Enjoy,
Jonathan Nieder (12):
  Makefile: add missing header file dependencies
  Makefile: make sure test helpers are rebuilt when headers change
  Makefile: remove wt-status.h from LIB_H
  Makefile: clean up http-walker.o dependency rules
  Makefile: drop dependency on $(wildcard */*.h)
  Makefile: transport.o depends on branch.h now
  Makefile: rearrange dependency rules
  Makefile: disable default implicit rules
  Makefile: list generated object files in OBJECTS macro
  Makefile: lazily compute header dependencies
  Makefile: list standalone program object files in PROGRAM_OBJS
  Teach Makefile to check header dependencies

```

## Jonathan Nieder, 2010-01-26 15:44

Subject: [PATCH 01/12] Makefile: add missing header file dependencies
Message-ID: <20100126154446.GB4895@progeny.tock>
URL: https://gitlist.dev/e/20100126154446.GB4895%40progeny.tock
In-Reply-To: <20100126154357.GA4895@progeny.tock>

```
LIB_H is missing exec_cmd.h and color.h.  cache.h includes
SHA1_HEADER, and thus so does almost everything else, so add that
to LIB_H, too.  xdiff-interface.h is not included by any header
files, but so many source files use xdiff that it is simplest to
include it in LIB_H, too.

xdiff-interface.o uses the xdiff library heavily; let it depend
on all xdiff headers to avoid needing to keep track of which
headers it uses.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
 Makefile |   23 ++++++++++++++++++++---
 1 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/Makefile b/Makefile
index fd7f51e..bad8f80 100644
--- a/Makefile
+++ b/Makefile
@@ -447,6 +447,7 @@ LIB_H += blob.h
 LIB_H += builtin.h
 LIB_H += cache.h
 LIB_H += cache-tree.h
+LIB_H += color.h
 LIB_H += commit.h
 LIB_H += compat/bswap.h
 LIB_H += compat/cygwin.h
@@ -457,6 +458,7 @@ LIB_H += delta.h
 LIB_H += diffcore.h
 LIB_H += diff.h
 LIB_H += dir.h
+LIB_H += exec_cmd.h
 LIB_H += fsck.h
 LIB_H += git-compat-util.h
 LIB_H += graph.h
@@ -499,6 +501,8 @@ LIB_H += unpack-trees.h
 LIB_H += userdiff.h
 LIB_H += utf8.h
 LIB_H += wt-status.h
+LIB_H += xdiff-interface.h
+LIB_H += xdiff/xdiff.h
 
 LIB_OBJS += abspath.o
 LIB_OBJS += advice.o
@@ -1281,10 +1285,12 @@ endif
 ifdef BLK_SHA1
 	SHA1_HEADER = "block-sha1/sha1.h"
 	LIB_OBJS += block-sha1/sha1.o
+	LIB_H += block-sha1/sha1.h
 else
 ifdef PPC_SHA1
 	SHA1_HEADER = "ppc/sha1.h"
 	LIB_OBJS += ppc/sha1.o ppc/sha1ppc.o
+	LIB_H += ppc/sha1.h
 else
 	SHA1_HEADER = <openssl/sha.h>
 	EXTLIBS += $(LIB_4_CRYPTO)
@@ -1620,9 +1626,9 @@ git-imap-send$X: imap-send.o $(GITLIBS)
 	$(QUIET_LINK)$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) \
 		$(LIBS) $(OPENSSL_LINK) $(OPENSSL_LIBSSL)
 
-http.o http-walker.o http-push.o: http.h
+http.o http-walker.o http-push.o remote-curl.o: http.h
 
-http.o http-walker.o: $(LIB_H)
+http.o http-walker.o remote-curl.o: $(LIB_H)
 
 git-http-fetch$X: revision.o http.o http-walker.o http-fetch.o $(GITLIBS)
 	$(QUIET_LINK)$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) \
@@ -1637,14 +1643,25 @@ git-remote-curl$X: remote-curl.o http.o http-walker.o $(GITLIBS)
 
 $(LIB_OBJS) $(BUILTIN_OBJS): $(LIB_H)
 $(patsubst git-%$X,%.o,$(PROGRAMS)) git.o: $(LIB_H) $(wildcard */*.h)
+builtin-branch.o builtin-checkout.o builtin-clone.o builtin-reset.o branch.o: branch.h
+builtin-bundle.o bundle.o transport.o: bundle.h
+builtin-bisect--helper.o builtin-rev-list.o bisect.o: bisect.h
+builtin-clone.o builtin-fetch-pack.o transport.o: fetch-pack.h
+builtin-send-pack.o transport.o: send-pack.h
+builtin-log.o builtin-shortlog.o: shortlog.h
+builtin-prune.o builtin-reflog.o reachable.o: reachable.h
 builtin-revert.o wt-status.o: wt-status.h
+builtin-tar-tree.o archive-tar.o: tar.h
+builtin-pack-objects.o: thread-utils.h
+http-fetch.o http-walker.o remote-curl.o transport.o walker.o: walker.h
 
 $(LIB_FILE): $(LIB_OBJS)
 	$(QUIET_AR)$(RM) $@ && $(AR) rcs $@ $(LIB_OBJS)
 
 XDIFF_OBJS=xdiff/xdiffi.o xdiff/xprepare.o xdiff/xutils.o xdiff/xemit.o \
 	xdiff/xmerge.o xdiff/xpatience.o
-$(XDIFF_OBJS): xdiff/xinclude.h xdiff/xmacros.h xdiff/xdiff.h xdiff/xtypes.h \
+xdiff-interface.o $(XDIFF_OBJS): \
+	xdiff/xinclude.h xdiff/xmacros.h xdiff/xdiff.h xdiff/xtypes.h \
 	xdiff/xutils.h xdiff/xprepare.h xdiff/xdiffi.h xdiff/xemit.h
 
 $(XDIFF_LIB): $(XDIFF_OBJS)
-- 
1.6.6

```

## Jonathan Nieder, 2010-01-26 15:45

Subject: [PATCH 02/12] Makefile: make sure test helpers are rebuilt when headers change
Message-ID: <20100126154554.GC4895@progeny.tock>
URL: https://gitlist.dev/e/20100126154554.GC4895%40progeny.tock
In-Reply-To: <20100126154357.GA4895@progeny.tock>

```
It is not worth the bother to maintain an up-to-date list of
which headers each test helper uses, so depend on $(LIB_H) to
catch them all.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
This applies to maint.  Please let me know if you are interested
in the corresponding patch for master.

 Makefile |   32 ++++++++++++++++----------------
 1 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/Makefile b/Makefile
index bad8f80..1670ee8 100644
--- a/Makefile
+++ b/Makefile
@@ -402,6 +402,18 @@ PROGRAMS += git-upload-pack$X
 PROGRAMS += git-var$X
 PROGRAMS += git-http-backend$X
 
+TEST_PROGRAMS += test-chmtime$X
+TEST_PROGRAMS += test-ctype$X
+TEST_PROGRAMS += test-date$X
+TEST_PROGRAMS += test-delta$X
+TEST_PROGRAMS += test-dump-cache-tree$X
+TEST_PROGRAMS += test-genrandom$X
+TEST_PROGRAMS += test-match-trees$X
+TEST_PROGRAMS += test-parse-options$X
+TEST_PROGRAMS += test-path-utils$X
+TEST_PROGRAMS += test-sha1$X
+TEST_PROGRAMS += test-sigchain$X
+
 # List built-in command $C whose implementation cmd_$C() is not in
 # builtin-$C.o but is linked in as part of some other command.
 BUILT_INS += $(patsubst builtin-%.o,git-%$X,$(BUILTIN_OBJS))
@@ -695,6 +707,8 @@ BUILTIN_OBJS += builtin-verify-pack.o
 BUILTIN_OBJS += builtin-verify-tag.o
 BUILTIN_OBJS += builtin-write-tree.o
 
+TEST_OBJS := $(patsubst test-%$X,test-%.o,$(TEST_PROGRAMS))
+
 GITLIBS = $(LIB_FILE) $(XDIFF_LIB)
 EXTLIBS =
 
@@ -1642,7 +1656,7 @@ git-remote-curl$X: remote-curl.o http.o http-walker.o $(GITLIBS)
 		$(LIBS) $(CURL_LIBCURL) $(EXPAT_LIBEXPAT)
 
 $(LIB_OBJS) $(BUILTIN_OBJS): $(LIB_H)
-$(patsubst git-%$X,%.o,$(PROGRAMS)) git.o: $(LIB_H) $(wildcard */*.h)
+$(patsubst git-%$X,%.o,$(PROGRAMS)) $(TEST_OBJS) git.o: $(LIB_H) $(wildcard */*.h)
 builtin-branch.o builtin-checkout.o builtin-clone.o builtin-reset.o branch.o: branch.h
 builtin-bundle.o bundle.o transport.o: bundle.h
 builtin-bisect--helper.o builtin-rev-list.o bisect.o: bisect.h
@@ -1732,18 +1746,6 @@ endif
 
 ### Testing rules
 
-TEST_PROGRAMS += test-chmtime$X
-TEST_PROGRAMS += test-ctype$X
-TEST_PROGRAMS += test-date$X
-TEST_PROGRAMS += test-delta$X
-TEST_PROGRAMS += test-dump-cache-tree$X
-TEST_PROGRAMS += test-genrandom$X
-TEST_PROGRAMS += test-match-trees$X
-TEST_PROGRAMS += test-parse-options$X
-TEST_PROGRAMS += test-path-utils$X
-TEST_PROGRAMS += test-sha1$X
-TEST_PROGRAMS += test-sigchain$X
-
 all:: $(TEST_PROGRAMS)
 
 # GNU make supports exporting all variables by "export" without parameters.
@@ -1763,9 +1765,7 @@ test-delta$X: diff-delta.o patch-delta.o
 
 test-parse-options$X: parse-options.o
 
-test-parse-options.o: parse-options.h
-
-.PRECIOUS: $(patsubst test-%$X,test-%.o,$(TEST_PROGRAMS))
+.PRECIOUS: $(TEST_OBJS)
 
 test-%$X: test-%.o $(GITLIBS)
 	$(QUIET_LINK)$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) $(LIBS)
-- 
1.6.6

```

## Jonathan Nieder, 2010-01-26 15:46

Subject: [PATCH 03/12] Makefile: remove wt-status.h from LIB_H
Message-ID: <20100126154616.GD4895@progeny.tock>
URL: https://gitlist.dev/e/20100126154616.GD4895%40progeny.tock
In-Reply-To: <20100126154357.GA4895@progeny.tock>

```
A list of the few translation units using this header is
half-populated already.  Including the dependency on this header
twice (once explicitly, once through LIB_H) makes it difficult to
figure out where future headers should be added to the Makefile.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
 Makefile |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index 1670ee8..8cf6383 100644
--- a/Makefile
+++ b/Makefile
@@ -512,7 +512,6 @@ LIB_H += tree-walk.h
 LIB_H += unpack-trees.h
 LIB_H += userdiff.h
 LIB_H += utf8.h
-LIB_H += wt-status.h
 LIB_H += xdiff-interface.h
 LIB_H += xdiff/xdiff.h
 
@@ -1664,7 +1663,7 @@ builtin-clone.o builtin-fetch-pack.o transport.o: fetch-pack.h
 builtin-send-pack.o transport.o: send-pack.h
 builtin-log.o builtin-shortlog.o: shortlog.h
 builtin-prune.o builtin-reflog.o reachable.o: reachable.h
-builtin-revert.o wt-status.o: wt-status.h
+builtin-commit.o builtin-revert.o wt-status.o: wt-status.h
 builtin-tar-tree.o archive-tar.o: tar.h
 builtin-pack-objects.o: thread-utils.h
 http-fetch.o http-walker.o remote-curl.o transport.o walker.o: walker.h
-- 
1.6.6

```

## Jonathan Nieder, 2010-01-26 15:46

Subject: [PATCH 04/12] Makefile: clean up http-walker.o dependency rules
Message-ID: <20100126154637.GE4895@progeny.tock>
URL: https://gitlist.dev/e/20100126154637.GE4895%40progeny.tock
In-Reply-To: <20100126154357.GA4895@progeny.tock>

```
http-walker.o depends on http.h twice: once in the rule listing
files that use http.h, and again in the rule explaining how to
build it.  Messy.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
 Makefile |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/Makefile b/Makefile
index 8cf6383..593801a 100644
--- a/Makefile
+++ b/Makefile
@@ -1628,7 +1628,7 @@ http.o: http.c GIT-CFLAGS
 	$(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) -DGIT_USER_AGENT='"git/$(GIT_VERSION)"' $<
 
 ifdef NO_EXPAT
-http-walker.o: http-walker.c http.h GIT-CFLAGS
+http-walker.o: http-walker.c GIT-CFLAGS
 	$(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) -DNO_EXPAT $<
 endif
 
-- 
1.6.6

```

## Jonathan Nieder, 2010-01-26 15:46

Subject: [PATCH 05/12] Makefile: drop dependency on $(wildcard */*.h)
Message-ID: <20100126154659.GF4895@progeny.tock>
URL: https://gitlist.dev/e/20100126154659.GF4895%40progeny.tock
In-Reply-To: <20100126154357.GA4895@progeny.tock>

```
The files this pulls in are already pulled in by other dependency
rules (some recently added).

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
 Makefile |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/Makefile b/Makefile
index 593801a..98810b2 100644
--- a/Makefile
+++ b/Makefile
@@ -1655,7 +1655,7 @@ git-remote-curl$X: remote-curl.o http.o http-walker.o $(GITLIBS)
 		$(LIBS) $(CURL_LIBCURL) $(EXPAT_LIBEXPAT)
 
 $(LIB_OBJS) $(BUILTIN_OBJS): $(LIB_H)
-$(patsubst git-%$X,%.o,$(PROGRAMS)) $(TEST_OBJS) git.o: $(LIB_H) $(wildcard */*.h)
+$(patsubst git-%$X,%.o,$(PROGRAMS)) $(TEST_OBJS) git.o: $(LIB_H)
 builtin-branch.o builtin-checkout.o builtin-clone.o builtin-reset.o branch.o: branch.h
 builtin-bundle.o bundle.o transport.o: bundle.h
 builtin-bisect--helper.o builtin-rev-list.o bisect.o: bisect.h
-- 
1.6.6

```

## Jonathan Nieder, 2010-01-26 15:47

Subject: [PATCH 06/12] Makefile: transport.o depends on branch.h now
Message-ID: <20100126154725.GG4895@progeny.tock>
URL: https://gitlist.dev/e/20100126154725.GG4895%40progeny.tock
In-Reply-To: <20100126154357.GA4895@progeny.tock>

```
Since commit e9fcd1e2 (Add push --set-upstream, 2010-01-16),
transport.c uses branch.h.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
 Makefile |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/Makefile b/Makefile
index 59a46e2..5678991 100644
--- a/Makefile
+++ b/Makefile
@@ -1719,7 +1719,7 @@ $(REMOTE_CURL_PRIMARY): remote-curl.o http.o http-walker.o $(GITLIBS)
 
 $(LIB_OBJS) $(BUILTIN_OBJS): $(LIB_H)
 $(patsubst git-%$X,%.o,$(PROGRAMS)) $(TEST_OBJS) git.o: $(LIB_H)
-builtin-branch.o builtin-checkout.o builtin-clone.o builtin-reset.o branch.o: branch.h
+builtin-branch.o builtin-checkout.o builtin-clone.o builtin-reset.o branch.o transport.o: branch.h
 builtin-bundle.o bundle.o transport.o: bundle.h
 builtin-bisect--helper.o builtin-rev-list.o bisect.o: bisect.h
 builtin-clone.o builtin-fetch-pack.o transport.o: fetch-pack.h
-- 
1.6.6

```

## Jonathan Nieder, 2010-01-26 15:49

Subject: [PATCH 07/12] Makefile: rearrange dependency rules
Message-ID: <20100126154933.GH4895@progeny.tock>
URL: https://gitlist.dev/e/20100126154933.GH4895%40progeny.tock
In-Reply-To: <20100126154357.GA4895@progeny.tock>

```
Put rules listing dependencies of compiled objects (.o files) on
header files (.h files) in one place, to make them easier to
compare and modify all at once.

Add a GIT_OBJS variable listing objects that depend on LIB_H,
for similar reasons.

No change in build-time behavior intended.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
 Makefile |   49 +++++++++++++++++++++++++------------------------
 1 files changed, 25 insertions(+), 24 deletions(-)

diff --git a/Makefile b/Makefile
index 5678991..84ce137 100644
--- a/Makefile
+++ b/Makefile
@@ -1666,6 +1666,12 @@ git.o git.spec \
 	$(patsubst %.perl,%,$(SCRIPT_PERL)) \
 	: GIT-VERSION-FILE
 
+GIT_OBJS := $(LIB_OBJS) $(BUILTIN_OBJS) $(TEST_OBJS) \
+	git.o http.o http-walker.o remote-curl.o \
+	$(patsubst git-%$X,%.o,$(PROGRAMS))
+XDIFF_OBJS = xdiff/xdiffi.o xdiff/xprepare.o xdiff/xutils.o xdiff/xemit.o \
+	xdiff/xmerge.o xdiff/xpatience.o
+
 %.o: %.c GIT-CFLAGS
 	$(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) $<
 %.s: %.c GIT-CFLAGS FORCE
@@ -1673,6 +1679,25 @@ git.o git.spec \
 %.o: %.S GIT-CFLAGS
 	$(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) $<
 
+$(GIT_OBJS): $(LIB_H)
+builtin-branch.o builtin-checkout.o builtin-clone.o builtin-reset.o branch.o transport.o: branch.h
+builtin-bundle.o bundle.o transport.o: bundle.h
+builtin-bisect--helper.o builtin-rev-list.o bisect.o: bisect.h
+builtin-clone.o builtin-fetch-pack.o transport.o: fetch-pack.h
+builtin-send-pack.o transport.o: send-pack.h
+builtin-log.o builtin-shortlog.o: shortlog.h
+builtin-prune.o builtin-reflog.o reachable.o: reachable.h
+builtin-commit.o builtin-revert.o wt-status.o: wt-status.h
+builtin-tar-tree.o archive-tar.o: tar.h
+builtin-pack-objects.o: thread-utils.h
+http-fetch.o http-walker.o remote-curl.o transport.o walker.o: walker.h
+http.o http-walker.o http-push.o remote-curl.o: http.h
+
+
+xdiff-interface.o $(XDIFF_OBJS): \
+	xdiff/xinclude.h xdiff/xmacros.h xdiff/xdiff.h xdiff/xtypes.h \
+	xdiff/xutils.h xdiff/xprepare.h xdiff/xdiffi.h xdiff/xemit.h
+
 exec_cmd.s exec_cmd.o: ALL_CFLAGS += \
 	'-DGIT_EXEC_PATH="$(gitexecdir_SQ)"' \
 	'-DBINDIR="$(bindir_relative_SQ)"' \
@@ -1696,10 +1721,6 @@ git-imap-send$X: imap-send.o $(GITLIBS)
 	$(QUIET_LINK)$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) \
 		$(LIBS) $(OPENSSL_LINK) $(OPENSSL_LIBSSL)
 
-http.o http-walker.o http-push.o remote-curl.o: http.h
-
-http.o http-walker.o remote-curl.o: $(LIB_H)
-
 git-http-fetch$X: revision.o http.o http-walker.o http-fetch.o $(GITLIBS)
 	$(QUIET_LINK)$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) \
 		$(LIBS) $(CURL_LIBCURL)
@@ -1717,29 +1738,9 @@ $(REMOTE_CURL_PRIMARY): remote-curl.o http.o http-walker.o $(GITLIBS)
 	$(QUIET_LINK)$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) \
 		$(LIBS) $(CURL_LIBCURL) $(EXPAT_LIBEXPAT)
 
-$(LIB_OBJS) $(BUILTIN_OBJS): $(LIB_H)
-$(patsubst git-%$X,%.o,$(PROGRAMS)) $(TEST_OBJS) git.o: $(LIB_H)
-builtin-branch.o builtin-checkout.o builtin-clone.o builtin-reset.o branch.o transport.o: branch.h
-builtin-bundle.o bundle.o transport.o: bundle.h
-builtin-bisect--helper.o builtin-rev-list.o bisect.o: bisect.h
-builtin-clone.o builtin-fetch-pack.o transport.o: fetch-pack.h
-builtin-send-pack.o transport.o: send-pack.h
-builtin-log.o builtin-shortlog.o: shortlog.h
-builtin-prune.o builtin-reflog.o reachable.o: reachable.h
-builtin-commit.o builtin-revert.o wt-status.o: wt-status.h
-builtin-tar-tree.o archive-tar.o: tar.h
-builtin-pack-objects.o: thread-utils.h
-http-fetch.o http-walker.o remote-curl.o transport.o walker.o: walker.h
-
 $(LIB_FILE): $(LIB_OBJS)
 	$(QUIET_AR)$(RM) $@ && $(AR) rcs $@ $(LIB_OBJS)
 
-XDIFF_OBJS=xdiff/xdiffi.o xdiff/xprepare.o xdiff/xutils.o xdiff/xemit.o \
-	xdiff/xmerge.o xdiff/xpatience.o
-xdiff-interface.o $(XDIFF_OBJS): \
-	xdiff/xinclude.h xdiff/xmacros.h xdiff/xdiff.h xdiff/xtypes.h \
-	xdiff/xutils.h xdiff/xprepare.h xdiff/xdiffi.h xdiff/xemit.h
-
 $(XDIFF_LIB): $(XDIFF_OBJS)
 	$(QUIET_AR)$(RM) $@ && $(AR) rcs $@ $(XDIFF_OBJS)
 
-- 
1.6.6

```

## Jonathan Nieder, 2010-01-26 15:51

Subject: [PATCH 08/12] Makefile: disable default implicit rules
Message-ID: <20100126155124.GI4895@progeny.tock>
URL: https://gitlist.dev/e/20100126155124.GI4895%40progeny.tock
In-Reply-To: <20100126154357.GA4895@progeny.tock>

```
The git makefile never uses any default implicit rules.
Unfortunately, if a prerequisite for one of the intended rules is
missing, a default rule can be used in its place:

	$ make var.s
	    CC var.s
	$ rm var.c
	$ make var.o
	    as   -o var.o var.s

Avoiding the default rules avoids this hard-to-debug behavior.
It also should speed things up a little in the normal case.

Future patches may restrict the scope of the %.o: %.c pattern.
This patch would then ensure that for targets not listed, we do
not fall back to the default rule.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
Sadly, this does not really speed things up in the normal case.
I am not sure why, but make needs the -r option to avoid
considering the default rules, even though clearing the .SUFFIXES:
guarantees it will never use them.

 Makefile |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/Makefile b/Makefile
index 84ce137..60ef711 100644
--- a/Makefile
+++ b/Makefile
@@ -1672,6 +1672,8 @@ GIT_OBJS := $(LIB_OBJS) $(BUILTIN_OBJS) $(TEST_OBJS) \
 XDIFF_OBJS = xdiff/xdiffi.o xdiff/xprepare.o xdiff/xutils.o xdiff/xemit.o \
 	xdiff/xmerge.o xdiff/xpatience.o
 
+.SUFFIXES:
+
 %.o: %.c GIT-CFLAGS
 	$(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) $<
 %.s: %.c GIT-CFLAGS FORCE
-- 
1.6.6

```

## Jonathan Nieder, 2010-01-26 15:52

Subject: [PATCH 09/12] Makefile: list generated object files in OBJECTS
Message-ID: <20100126155211.GJ4895@progeny.tock>
URL: https://gitlist.dev/e/20100126155211.GJ4895%40progeny.tock
In-Reply-To: <20100126154357.GA4895@progeny.tock>

```
Set the OBJECTS variable to a comprehensive list of all object
file targets.  To make sure it is truly comprehensive, restrict
the scope of the %.o pattern rule to only generate objects in
this list.

Attempts to build other object files will fail loudly:

	$ touch foo.c
	$ make foo.o
	make: *** No rule to make target `foo.o'.  Stop.

providing a reminder to add the new object to the OBJECTS list.

The new variable is otherwise unused.  The intent is for later
patches to take advantage of it.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
 Makefile |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index 60ef711..0e4e8ff 100644
--- a/Makefile
+++ b/Makefile
@@ -1671,14 +1671,19 @@ GIT_OBJS := $(LIB_OBJS) $(BUILTIN_OBJS) $(TEST_OBJS) \
 	$(patsubst git-%$X,%.o,$(PROGRAMS))
 XDIFF_OBJS = xdiff/xdiffi.o xdiff/xprepare.o xdiff/xutils.o xdiff/xemit.o \
 	xdiff/xmerge.o xdiff/xpatience.o
+OBJECTS := $(GIT_OBJS) $(XDIFF_OBJS)
+
+ASM_SRC := $(wildcard $(OBJECTS:o=S))
+ASM_OBJ := $(ASM_SRC:S=o)
+C_OBJ := $(filter-out $(ASM_OBJ),$(OBJECTS))
 
 .SUFFIXES:
 
-%.o: %.c GIT-CFLAGS
+$(C_OBJ): %.o: %.c GIT-CFLAGS
 	$(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) $<
 %.s: %.c GIT-CFLAGS FORCE
 	$(QUIET_CC)$(CC) -S $(ALL_CFLAGS) $<
-%.o: %.S GIT-CFLAGS
+$(ASM_OBJ): %.o: %.S GIT-CFLAGS
 	$(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) $<
 
 $(GIT_OBJS): $(LIB_H)
-- 
1.6.6

```

## Jonathan Nieder, 2010-01-26 15:52

Subject: [PATCH 10/12] Makefile: lazily compute header dependencies
Message-ID: <20100126155249.GK4895@progeny.tock>
URL: https://gitlist.dev/e/20100126155249.GK4895%40progeny.tock
In-Reply-To: <20100126154357.GA4895@progeny.tock>

```
Use the gcc -MMD -MP -MF options to generate dependency rules as
a byproduct when building .o files if the
COMPUTE_HEADER_DEPENDENCIES variable is defined.  That variable
is left undefined by default for now.

As each object file is built, write a makefile fragment
containing its dependencies in the deps/ subdirectory of its
containing directory.  The deps/ directories should be generated
if they are missing at the start of each build.  So let each
object file depend on $(missing_dep_dirs), which lists only the
directories of this kind that are missing to avoid needlessly
regenerating files when the directories' timestamps change.

gcc learned the -MMD -MP -MF options in version 3.0, so most gcc
users should have them by now.

The dependencies this option computes are more specific than the
rough estimates hard-coded in the Makefile, greatly speeding up
rebuilds when only a little-used header file has changed.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
 .gitignore |    1 +
 Makefile   |   49 ++++++++++++++++++++++++++++++++++++++++++++-----
 2 files changed, 45 insertions(+), 5 deletions(-)

diff --git a/.gitignore b/.gitignore
index 8df8f88..7b3acb7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -177,6 +177,7 @@
 *.exe
 *.[aos]
 *.py[co]
+*.o.d
 *+
 /config.mak
 /autom4te.cache
diff --git a/Makefile b/Makefile
index 0e4e8ff..2e75f05 100644
--- a/Makefile
+++ b/Makefile
@@ -217,6 +217,10 @@ all::
 #   DEFAULT_EDITOR='~/bin/vi',
 #   DEFAULT_EDITOR='$GIT_FALLBACK_EDITOR',
 #   DEFAULT_EDITOR='"C:\Program Files\Vim\gvim.exe" --nofork'
+#
+# Define COMPUTE_HEADER_DEPENDENCIES if your compiler supports the -MMD option
+# and you want to avoid rebuilding objects when an unrelated header file
+# changes.
 
 GIT-VERSION-FILE: FORCE
 	@$(SHELL_PATH) ./GIT-VERSION-GEN
@@ -1677,14 +1681,48 @@ ASM_SRC := $(wildcard $(OBJECTS:o=S))
 ASM_OBJ := $(ASM_SRC:S=o)
 C_OBJ := $(filter-out $(ASM_OBJ),$(OBJECTS))
 
+ifdef COMPUTE_HEADER_DEPENDENCIES
+dep_dirs := $(addsuffix deps,$(sort $(dir $(OBJECTS))))
+$(dep_dirs):
+	mkdir -p $@
+
+missing_dep_dirs := $(filter-out $(wildcard $(dep_dirs)),$(dep_dirs))
+else
+dep_dirs =
+missing_dep_dirs =
+endif
+
 .SUFFIXES:
 
-$(C_OBJ): %.o: %.c GIT-CFLAGS
-	$(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) $<
+$(C_OBJ): %.o: %.c GIT-CFLAGS $(missing_dep_dirs)
+	$(QUIET_CC)$(CC) -o $*.o -c $(dep_args) $(ALL_CFLAGS) $<
 %.s: %.c GIT-CFLAGS FORCE
 	$(QUIET_CC)$(CC) -S $(ALL_CFLAGS) $<
-$(ASM_OBJ): %.o: %.S GIT-CFLAGS
-	$(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) $<
+$(ASM_OBJ): %.o: %.S GIT-CFLAGS $(missing_dep_dirs)
+	$(QUIET_CC)$(CC) -o $*.o -c $(dep_args) $(ALL_CFLAGS) $<
+
+ifdef COMPUTE_HEADER_DEPENDENCIES
+# Take advantage of gcc's on-the-fly dependency generation
+# See <http://gcc.gnu.org/gcc-3.0/features.html>.
+dep_files := $(wildcard $(foreach f,$(OBJECTS),$(dir f)deps/$(notdir $f).d))
+ifneq ($(dep_files),)
+include $(dep_files)
+endif
+
+dep_file = $(dir $@)deps/$(notdir $@).d
+dep_args = -MF $(dep_file) -MMD -MP
+else
+dep_args =
+
+# Dependencies on header files, for platforms that do not support
+# the gcc -MMD option.
+#
+# Dependencies on automatically generated headers such as common-cmds.h
+# should _not_ be included here, since they are necessary even when
+# building an object for the first time.
+#
+# XXX. Please check occasionally that these include all dependencies
+# gcc detects!
 
 $(GIT_OBJS): $(LIB_H)
 builtin-branch.o builtin-checkout.o builtin-clone.o builtin-reset.o branch.o transport.o: branch.h
@@ -1700,10 +1738,10 @@ builtin-pack-objects.o: thread-utils.h
 http-fetch.o http-walker.o remote-curl.o transport.o walker.o: walker.h
 http.o http-walker.o http-push.o remote-curl.o: http.h
 
-
 xdiff-interface.o $(XDIFF_OBJS): \
 	xdiff/xinclude.h xdiff/xmacros.h xdiff/xdiff.h xdiff/xtypes.h \
 	xdiff/xutils.h xdiff/xprepare.h xdiff/xdiffi.h xdiff/xemit.h
+endif
 
 exec_cmd.s exec_cmd.o: ALL_CFLAGS += \
 	'-DGIT_EXEC_PATH="$(gitexecdir_SQ)"' \
@@ -2011,6 +2049,7 @@ clean:
 	$(RM) $(ALL_PROGRAMS) $(BUILT_INS) git$X
 	$(RM) $(TEST_PROGRAMS)
 	$(RM) -r bin-wrappers
+	$(RM) -r $(dep_dirs)
 	$(RM) *.spec *.pyc *.pyo */*.pyc */*.pyo common-cmds.h TAGS tags cscope*
 	$(RM) -r autom4te.cache
 	$(RM) config.log config.mak.autogen config.mak.append config.status config.cache
-- 
1.6.6

```

## Jonathan Nieder, 2010-01-26 15:54

Subject: [PATCH 11/12] Makefile: list standalone program object files in PROGRAM_OBJS
Message-ID: <20100126155423.GL4895@progeny.tock>
URL: https://gitlist.dev/e/20100126155423.GL4895%40progeny.tock
In-Reply-To: <20100126154357.GA4895@progeny.tock>

```
Because of new commands like git-remote-http, the OBJECTS list
contains fictitious objects such as remote-http.o.  Thus any
out-of-tree rules that require all $(OBJECTS) to be buildable
are broken.  Add a list of real program objects to avoid this
problem.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
Preparing for patch 12.

 Makefile |   24 +++++++++++++++---------
 1 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/Makefile b/Makefile
index 2e75f05..ceaae1c 100644
--- a/Makefile
+++ b/Makefile
@@ -341,6 +341,7 @@ COMPAT_CFLAGS =
 COMPAT_OBJS =
 LIB_H =
 LIB_OBJS =
+PROGRAM_OBJS =
 PROGRAMS =
 SCRIPT_PERL =
 SCRIPT_PYTHON =
@@ -390,12 +391,15 @@ EXTRA_PROGRAMS =
 
 # ... and all the rest that could be moved out of bindir to gitexecdir
 PROGRAMS += $(EXTRA_PROGRAMS)
-PROGRAMS += git-fast-import$X
-PROGRAMS += git-imap-send$X
-PROGRAMS += git-shell$X
-PROGRAMS += git-show-index$X
-PROGRAMS += git-upload-pack$X
-PROGRAMS += git-http-backend$X
+
+PROGRAM_OBJS += fast-import.o
+PROGRAM_OBJS += imap-send.o
+PROGRAM_OBJS += shell.o
+PROGRAM_OBJS += show-index.o
+PROGRAM_OBJS += upload-pack.o
+PROGRAM_OBJS += http-backend.o
+
+PROGRAMS += $(patsubst %.o,git-%$X,$(PROGRAM_OBJS))
 
 TEST_PROGRAMS_NEED_X += test-chmtime
 TEST_PROGRAMS_NEED_X += test-ctype
@@ -1139,10 +1143,12 @@ else
 	REMOTE_CURL_PRIMARY = git-remote-http$X
 	REMOTE_CURL_ALIASES = git-remote-https$X git-remote-ftp$X git-remote-ftps$X
 	REMOTE_CURL_NAMES = $(REMOTE_CURL_PRIMARY) $(REMOTE_CURL_ALIASES)
+	PROGRAM_OBJS += http-fetch.o
 	PROGRAMS += $(REMOTE_CURL_NAMES) git-http-fetch$X
 	curl_check := $(shell (echo 070908; curl-config --vernum) | sort -r | sed -ne 2p)
 	ifeq "$(curl_check)" "070908"
 		ifndef NO_EXPAT
+			PROGRAM_OBJS += http-push.o
 			PROGRAMS += git-http-push$X
 		endif
 	endif
@@ -1163,6 +1169,7 @@ endif
 EXTLIBS += -lz
 
 ifndef NO_POSIX_ONLY_PROGRAMS
+	PROGRAM_OBJS += daemon.o
 	PROGRAMS += git-daemon$X
 endif
 ifndef NO_OPENSSL
@@ -1670,9 +1677,8 @@ git.o git.spec \
 	$(patsubst %.perl,%,$(SCRIPT_PERL)) \
 	: GIT-VERSION-FILE
 
-GIT_OBJS := $(LIB_OBJS) $(BUILTIN_OBJS) $(TEST_OBJS) \
-	git.o http.o http-walker.o remote-curl.o \
-	$(patsubst git-%$X,%.o,$(PROGRAMS))
+GIT_OBJS := $(LIB_OBJS) $(BUILTIN_OBJS) $(PROGRAM_OBJS) $(TEST_OBJS) \
+	git.o http.o http-walker.o remote-curl.o
 XDIFF_OBJS = xdiff/xdiffi.o xdiff/xprepare.o xdiff/xutils.o xdiff/xemit.o \
 	xdiff/xmerge.o xdiff/xpatience.o
 OBJECTS := $(GIT_OBJS) $(XDIFF_OBJS)
-- 
1.6.6

```

## Jonathan Nieder, 2010-01-26 15:57

Subject: [PATCH 12/12] Teach Makefile to check header dependencies
Message-ID: <20100126155714.GM4895@progeny.tock>
URL: https://gitlist.dev/e/20100126155714.GM4895%40progeny.tock
In-Reply-To: <20100126154357.GA4895@progeny.tock>

```
Add a target to use the gcc-generated makefile snippets for
dependencies on header files to check the hard-coded dependencies.

With this patch applied, if any dependencies are missing, then

	make clean
	make COMPUTE_HEADER_DEPENDENCIES=YesPlease
	make CHECK_HEADER_DEPENDENCIES=YesPlease

will produce an error message like the following:

	CHECK fast-import.o
	missing dependencies: exec_cmd.h
	make: *** [fast-import.o] Error 1

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
That’s the end of the series.  Thanks for reading.

 Makefile |   95 ++++++++++++++++++++++++++++++++++++++++++++++++++++----------
 1 files changed, 80 insertions(+), 15 deletions(-)

diff --git a/Makefile b/Makefile
index ceaae1c..be357a8 100644
--- a/Makefile
+++ b/Makefile
@@ -221,6 +221,9 @@ all::
 # Define COMPUTE_HEADER_DEPENDENCIES if your compiler supports the -MMD option
 # and you want to avoid rebuilding objects when an unrelated header file
 # changes.
+#
+# Define CHECK_HEADER_DEPENDENCIES to check for problems in the hard-coded
+# dependency rules.
 
 GIT-VERSION-FILE: FORCE
 	@$(SHELL_PATH) ./GIT-VERSION-GEN
@@ -1088,6 +1091,14 @@ endif
 -include config.mak.autogen
 -include config.mak
 
+ifdef CHECK_HEADER_DEPENDENCIES
+USE_COMPUTED_HEADER_DEPENDENCIES =
+endif
+
+ifdef COMPUTE_HEADER_DEPENDENCIES
+USE_COMPUTED_HEADER_DEPENDENCIES = YesPlease
+endif
+
 ifdef SANE_TOOL_PATH
 SANE_TOOL_PATH_SQ = $(subst ','\'',$(SANE_TOOL_PATH))
 BROKEN_PATH_FIX = 's|^\# @@BROKEN_PATH_FIX@@$$|git_broken_path_fix $(SANE_TOOL_PATH_SQ)|'
@@ -1683,9 +1694,7 @@ XDIFF_OBJS = xdiff/xdiffi.o xdiff/xprepare.o xdiff/xutils.o xdiff/xemit.o \
 	xdiff/xmerge.o xdiff/xpatience.o
 OBJECTS := $(GIT_OBJS) $(XDIFF_OBJS)
 
-ASM_SRC := $(wildcard $(OBJECTS:o=S))
-ASM_OBJ := $(ASM_SRC:S=o)
-C_OBJ := $(filter-out $(ASM_OBJ),$(OBJECTS))
+dep_files := $(foreach f,$(OBJECTS),$(dir $f)deps/$(notdir $f).d)
 
 ifdef COMPUTE_HEADER_DEPENDENCIES
 dep_dirs := $(addsuffix deps,$(sort $(dir $(OBJECTS))))
@@ -1693,33 +1702,89 @@ $(dep_dirs):
 	mkdir -p $@
 
 missing_dep_dirs := $(filter-out $(wildcard $(dep_dirs)),$(dep_dirs))
-else
+dep_file = $(dir $@)deps/$(notdir $@).d
+dep_args = -MF $(dep_file) -MMD -MP
+ifdef CHECK_HEADER_DEPENDENCIES
+$(error cannot compute header dependencies outside a normal build. \
+Please unset CHECK_HEADER_DEPENDENCIES and try again)
+endif
+endif
+
+ifndef COMPUTE_HEADER_DEPENDENCIES
+ifndef CHECK_HEADER_DEPENDENCIES
 dep_dirs =
 missing_dep_dirs =
+dep_args =
+endif
+endif
+
+ifdef CHECK_HEADER_DEPENDENCIES
+ifndef PRINT_HEADER_DEPENDENCIES
+missing_deps = $(filter-out $(notdir $^), \
+	$(notdir $(shell $(MAKE) -s $@ \
+		CHECK_HEADER_DEPENDENCIES=YesPlease \
+		USE_COMPUTED_HEADER_DEPENDENCIES=YesPlease \
+		PRINT_HEADER_DEPENDENCIES=YesPlease)))
+endif
 endif
 
+ASM_SRC := $(wildcard $(OBJECTS:o=S))
+ASM_OBJ := $(ASM_SRC:S=o)
+C_OBJ := $(filter-out $(ASM_OBJ),$(OBJECTS))
+
 .SUFFIXES:
 
+ifdef PRINT_HEADER_DEPENDENCIES
+$(C_OBJ): %.o: %.c FORCE
+	echo $^
+$(ASM_OBJ): %.o: %.S FORCE
+	echo $^
+
+ifndef CHECK_HEADER_DEPENDENCIES
+$(error cannot print header dependencies during a normal build. \
+Please set CHECK_HEADER_DEPENDENCIES and try again)
+endif
+endif
+
+ifndef PRINT_HEADER_DEPENDENCIES
+ifdef CHECK_HEADER_DEPENDENCIES
+$(C_OBJ): %.o: %.c $(dep_files) FORCE
+	@set -e; echo CHECK $@; \
+	missing_deps="$(missing_deps)"; \
+	if test "$$missing_deps"; \
+	then \
+		echo missing dependencies: $$missing_deps; \
+		false; \
+	fi
+$(ASM_OBJ): %.o: %.S $(dep_files) FORCE
+	@set -e; echo CHECK $@; \
+	missing_deps="$(missing_deps)"; \
+	if test "$$missing_deps"; \
+	then \
+		echo missing dependencies: $$missing_deps; \
+		false; \
+	fi
+endif
+endif
+
+ifndef CHECK_HEADER_DEPENDENCIES
 $(C_OBJ): %.o: %.c GIT-CFLAGS $(missing_dep_dirs)
 	$(QUIET_CC)$(CC) -o $*.o -c $(dep_args) $(ALL_CFLAGS) $<
-%.s: %.c GIT-CFLAGS FORCE
-	$(QUIET_CC)$(CC) -S $(ALL_CFLAGS) $<
 $(ASM_OBJ): %.o: %.S GIT-CFLAGS $(missing_dep_dirs)
 	$(QUIET_CC)$(CC) -o $*.o -c $(dep_args) $(ALL_CFLAGS) $<
+endif
 
-ifdef COMPUTE_HEADER_DEPENDENCIES
+%.s: %.c GIT-CFLAGS FORCE
+	$(QUIET_CC)$(CC) -S $(ALL_CFLAGS) $<
+
+ifdef USE_COMPUTED_HEADER_DEPENDENCIES
 # Take advantage of gcc's on-the-fly dependency generation
 # See <http://gcc.gnu.org/gcc-3.0/features.html>.
-dep_files := $(wildcard $(foreach f,$(OBJECTS),$(dir f)deps/$(notdir $f).d))
-ifneq ($(dep_files),)
-include $(dep_files)
+dep_files_present := $(wildcard $(dep_files))
+ifneq ($(dep_files_present),)
+include $(dep_files_present)
 endif
-
-dep_file = $(dir $@)deps/$(notdir $@).d
-dep_args = -MF $(dep_file) -MMD -MP
 else
-dep_args =
-
 # Dependencies on header files, for platforms that do not support
 # the gcc -MMD option.
 #
-- 
1.6.6

```

## Jonathan Nieder, 2010-01-26 16:19

Subject: Re: [PATCH 00/12] Re: Makefile: add missing header dependency rules
Message-ID: <20100126161954.GA5550@progeny.tock>
URL: https://gitlist.dev/e/20100126161954.GA5550%40progeny.tock
In-Reply-To: <20100126154357.GA4895@progeny.tock>

```
Jonathan Nieder wrote:

> The remainder of this series is based on a merge of master and
> patches 1-5:
[...]
> Jonathan Nieder (12):
>   Makefile: add missing header file dependencies
>   Makefile: make sure test helpers are rebuilt when headers change
>   Makefile: remove wt-status.h from LIB_H
>   Makefile: clean up http-walker.o dependency rules
>   Makefile: drop dependency on $(wildcard */*.h)
>   Makefile: transport.o depends on branch.h now
>   Makefile: rearrange dependency rules
>   Makefile: disable default implicit rules
>   Makefile: list generated object files in OBJECTS macro
>   Makefile: lazily compute header dependencies
>   Makefile: list standalone program object files in PROGRAM_OBJS
>   Teach Makefile to check header dependencies

For those would like to avoid redoing the conflict resolution (and
who wouldn’t?), this series is also available in the git repository
at

  git://repo.or.cz/git/jrn.git autodep

If you’re interested, please take a look around and try it out.  I’d
be happy to hear about any bugs you find.

Thanks again,
Jonathan

```

## Jonathan Nieder, 2010-01-27 09:07

Subject: [PATCH v2 11/12] Makefile: list standalone program object files in PROGRAM_OBJS
Message-ID: <20100127090423.GA28252@progeny.tock>
URL: https://gitlist.dev/e/20100127090423.GA28252%40progeny.tock
In-Reply-To: <20100126155423.GL4895@progeny.tock>

```
Because of new commands like git-remote-http, the OBJECTS list
contains fictitious objects such as remote-http.o.  Thus any
out-of-tree rules that require all $(OBJECTS) to be buildable
are broken.  Add a list of real program objects to avoid this
problem.

To avoid duplication of effort, calculate the command list in
the PROGRAMS variable using the expansion of PROGRAM_OBJS.
This calculation occurs at the time $(PROGRAMS) is expanded,
so later additions to PROGRAM_OBJS will be reflected in it,
provided they occur before the build rules begin on line 1489.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
The previous version of this patch had a bug: I assumed that

	PROGRAMS += $(patsubst %.o,git-%$X,$(PROGRAM_OBJS))

would add to PROGRAMS a list of command names derived from the value
of PROGRAM_OBJS at the time that line is first read; but in fact, what
matters is the value of PROGRAM_OBJS at expansion time.

More importantly, my process had a bug: I didn’t try 'make install'
before sending.  Sorry about that.  Here’s a fixed patch, at least.

I have pushed out this fix to

  git://repo.or.cz/git/jrn.git autodep-rebased
  git://repo.or.cz/git/jrn.git autodep

The former has been rerolled to include the fixed patch 11; the
latter includes a fixup commit at the end.

Thanks to Junio for the report.

 Makefile |   28 ++++++++++++++++------------
 1 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/Makefile b/Makefile
index df36173..630687f 100644
--- a/Makefile
+++ b/Makefile
@@ -341,6 +341,7 @@ COMPAT_CFLAGS =
 COMPAT_OBJS =
 LIB_H =
 LIB_OBJS =
+PROGRAM_OBJS =
 PROGRAMS =
 SCRIPT_PERL =
 SCRIPT_PYTHON =
@@ -390,12 +391,15 @@ EXTRA_PROGRAMS =
 
 # ... and all the rest that could be moved out of bindir to gitexecdir
 PROGRAMS += $(EXTRA_PROGRAMS)
-PROGRAMS += git-fast-import$X
-PROGRAMS += git-imap-send$X
-PROGRAMS += git-shell$X
-PROGRAMS += git-show-index$X
-PROGRAMS += git-upload-pack$X
-PROGRAMS += git-http-backend$X
+
+PROGRAM_OBJS += fast-import.o
+PROGRAM_OBJS += imap-send.o
+PROGRAM_OBJS += shell.o
+PROGRAM_OBJS += show-index.o
+PROGRAM_OBJS += upload-pack.o
+PROGRAM_OBJS += http-backend.o
+
+PROGRAMS += $(patsubst %.o,git-%$X,$(PROGRAM_OBJS))
 
 TEST_PROGRAMS_NEED_X += test-chmtime
 TEST_PROGRAMS_NEED_X += test-ctype
@@ -1139,11 +1143,12 @@ else
 	REMOTE_CURL_PRIMARY = git-remote-http$X
 	REMOTE_CURL_ALIASES = git-remote-https$X git-remote-ftp$X git-remote-ftps$X
 	REMOTE_CURL_NAMES = $(REMOTE_CURL_PRIMARY) $(REMOTE_CURL_ALIASES)
-	PROGRAMS += $(REMOTE_CURL_NAMES) git-http-fetch$X
+	PROGRAM_OBJS += http-fetch.o
+	PROGRAMS += $(REMOTE_CURL_NAMES)
 	curl_check := $(shell (echo 070908; curl-config --vernum) | sort -r | sed -ne 2p)
 	ifeq "$(curl_check)" "070908"
 		ifndef NO_EXPAT
-			PROGRAMS += git-http-push$X
+			PROGRAM_OBJS += http-push.o
 		endif
 	endif
 	ifndef NO_EXPAT
@@ -1163,7 +1168,7 @@ endif
 EXTLIBS += -lz
 
 ifndef NO_POSIX_ONLY_PROGRAMS
-	PROGRAMS += git-daemon$X
+	PROGRAM_OBJS += daemon.o
 endif
 ifndef NO_OPENSSL
 	OPENSSL_LIBSSL = -lssl
@@ -1670,9 +1675,8 @@ git.o git.spec \
 	$(patsubst %.perl,%,$(SCRIPT_PERL)) \
 	: GIT-VERSION-FILE
 
-GIT_OBJS := $(LIB_OBJS) $(BUILTIN_OBJS) $(TEST_OBJS) \
-	git.o http.o http-walker.o remote-curl.o \
-	$(patsubst git-%$X,%.o,$(PROGRAMS))
+GIT_OBJS := $(LIB_OBJS) $(BUILTIN_OBJS) $(PROGRAM_OBJS) $(TEST_OBJS) \
+	git.o http.o http-walker.o remote-curl.o
 XDIFF_OBJS = xdiff/xdiffi.o xdiff/xprepare.o xdiff/xutils.o xdiff/xemit.o \
 	xdiff/xmerge.o xdiff/xpatience.o
 OBJECTS := $(GIT_OBJS) $(XDIFF_OBJS)
-- 
1.6.6

```

## Junio C Hamano, 2010-01-31 20:42

Subject: Re: [PATCH 12/12] Teach Makefile to check header dependencies
Message-ID: <7viqaic8gs.fsf@alter.siamese.dyndns.org>
URL: https://gitlist.dev/e/7viqaic8gs.fsf%40alter.siamese.dyndns.org
In-Reply-To: <20100126155714.GM4895@progeny.tock>

```
Jonathan Nieder <jrnieder@gmail.com> writes:

> Add a target to use the gcc-generated makefile snippets for
> dependencies on header files to check the hard-coded dependencies.
>
> With this patch applied, if any dependencies are missing, then
>
> 	make clean
> 	make COMPUTE_HEADER_DEPENDENCIES=YesPlease
> 	make CHECK_HEADER_DEPENDENCIES=YesPlease
>
> will produce an error message like the following:
>
> 	CHECK fast-import.o
> 	missing dependencies: exec_cmd.h
> 	make: *** [fast-import.o] Error 1
>
> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
> ---
> That’s the end of the series.  Thanks for reading.

Thanks.

Three observations:

 * "make distclean" should remove $(dep_files);

 * "deps/" should probably be ".depend/" or something less distracting;

 * I wish CHECK_HEADER_DEPENDENCIES pointed out unnecessary dependencies
   hardcoded in the Makefile.

-- >8 --
Subject: [PATCH] Makefile: "make distclean" should remove dependency files

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 Makefile |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/Makefile b/Makefile
index 45b1f54..8578b31 100644
--- a/Makefile
+++ b/Makefile
@@ -2110,7 +2110,7 @@ dist-doc:
 ### Cleaning rules
 
 distclean: clean
-	$(RM) configure
+	$(RM) configure $(dep_files)
 
 clean:
 	$(RM) *.o block-sha1/*.o ppc/*.o compat/*.o compat/*/*.o xdiff/*.o \
-- 
1.7.0.rc1.141.gd3fd2

```

## Jonathan Nieder, 2010-01-31 21:14

Subject: Re: [PATCH 12/12] Teach Makefile to check header dependencies
Message-ID: <20100131211429.GA4550@progeny.tock>
URL: https://gitlist.dev/e/20100131211429.GA4550%40progeny.tock
In-Reply-To: <7viqaic8gs.fsf@alter.siamese.dyndns.org>

```
Junio C Hamano wrote:

> Thanks.
> 
> Three observations:
> 
>  * "make distclean" should remove $(dep_files);

It removes $(dep_dirs) in "make clean".  Do you think they should be
kept around?  Or is this about when COMPUTE_HEADER_DEPENDENCIES is
turned off but .o.d files remain?

>  * "deps/" should probably be ".depend/" or something less distracting;

Good idea.

>  * I wish CHECK_HEADER_DEPENDENCIES pointed out unnecessary dependencies
>    hardcoded in the Makefile.

That would not be hard to do, but wouldn’t the $(GIT_OBJS): $(LIB_H)
rule create a lot of noise?

How about if it checks for duplicate dependencies and unnecessary
dependencies that are not in LIB_H?

> -- >8 --
> Subject: [PATCH] Makefile: "make distclean" should remove dependency files
> 
> Signed-off-by: Junio C Hamano <gitster@pobox.com>
> ---
>  Makefile |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/Makefile b/Makefile
> index 45b1f54..8578b31 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -2110,7 +2110,7 @@ dist-doc:
>  ### Cleaning rules
>  
>  distclean: clean
> -	$(RM) configure
> +	$(RM) configure $(dep_files)

This couldn’t hurt, but I wonder whether it is necessary; see above.

Thanks for the feedback,
Jonathan

```

## Jonathan Nieder, 2010-01-31 21:23

Subject: [PATCH 13/12] Makefile: tuck away generated makefile fragments in .depend
Message-ID: <20100131212353.GA4636@progeny.tock>
URL: https://gitlist.dev/e/20100131212353.GA4636%40progeny.tock
In-Reply-To: <7viqaic8gs.fsf@alter.siamese.dyndns.org>

```
When building with COMPUTE_HEADER_DEPENDENCIES on, save
dependency information to .depend/ instead of deps/ so it does
not show up in ‘ls’ output.  Otherwise, the extra directories can
be distracting.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
Junio C Hamano wrote:

>  * "deps/" should probably be ".depend/" or something less distracting;

Good idea.  Here goes...

 Makefile |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/Makefile b/Makefile
index 45b1f54..c939139 100644
--- a/Makefile
+++ b/Makefile
@@ -1692,15 +1692,15 @@ XDIFF_OBJS = xdiff/xdiffi.o xdiff/xprepare.o xdiff/xutils.o xdiff/xemit.o \
 	xdiff/xmerge.o xdiff/xpatience.o
 OBJECTS := $(GIT_OBJS) $(XDIFF_OBJS)
 
-dep_files := $(foreach f,$(OBJECTS),$(dir $f)deps/$(notdir $f).d)
+dep_files := $(foreach f,$(OBJECTS),$(dir $f).depend/$(notdir $f).d)
 
 ifdef COMPUTE_HEADER_DEPENDENCIES
-dep_dirs := $(addsuffix deps,$(sort $(dir $(OBJECTS))))
+dep_dirs := $(addsuffix .depend,$(sort $(dir $(OBJECTS))))
 $(dep_dirs):
 	mkdir -p $@
 
 missing_dep_dirs := $(filter-out $(wildcard $(dep_dirs)),$(dep_dirs))
-dep_file = $(dir $@)deps/$(notdir $@).d
+dep_file = $(dir $@).depend/$(notdir $@).d
 dep_args = -MF $(dep_file) -MMD -MP
 ifdef CHECK_HEADER_DEPENDENCIES
 $(error cannot compute header dependencies outside a normal build. \
-- 
1.7.0.rc1

```

## Junio C Hamano, 2010-01-31 21:26

Subject: Re: [PATCH 12/12] Teach Makefile to check header dependencies
Message-ID: <7vaavuc6f4.fsf@alter.siamese.dyndns.org>
URL: https://gitlist.dev/e/7vaavuc6f4.fsf%40alter.siamese.dyndns.org
In-Reply-To: <20100131211429.GA4550@progeny.tock>

```
Jonathan Nieder <jrnieder@gmail.com> writes:

> Junio C Hamano wrote:
> ...
>> Three observations:
>> 
>>  * "make distclean" should remove $(dep_files);
>
> It removes $(dep_dirs) in "make clean".  Do you think they should be
> kept around?  Or is this about when COMPUTE_HEADER_DEPENDENCIES is
> turned off but .o.d files remain?

Yes, the last one.  After playing around, with or without COMPUTE/CHECK,
and then making a final build, it would be nice if "make distclean"
removed all the intermediate build products without the same special
"debug build" options (and without COMPUTE, dep_dirs is empty so nothing
is removed).  It is also fine if "make clean" did so.

>>  * I wish CHECK_HEADER_DEPENDENCIES pointed out unnecessary dependencies
>>    hardcoded in the Makefile.
>
> That would not be hard to do, but wouldn’t the $(GIT_OBJS): $(LIB_H)
> rule create a lot of noise?
>
> How about if it checks for duplicate dependencies and unnecessary
> dependencies that are not in LIB_H?

That would be ideal, I think.

```

## Jonathan Nieder, 2010-01-31 21:37

Subject: [PATCH 14/12] Makefile: always remove .depend directories on 'make clean'
Message-ID: <20100131213725.GB4636@progeny.tock>
URL: https://gitlist.dev/e/20100131213725.GB4636%40progeny.tock
In-Reply-To: <7vaavuc6f4.fsf@alter.siamese.dyndns.org>

```
Even if COMPUTE_HEADER_DEPENDENCIES is not set, some .o.d files
might be lying around from previous builds when it was.  This
is especially likely because using the CHECK_HEADER_DEPENDENCIES
feature requires building sometimes with COMPUTE... on and
sometimes with it off.  At the end of such an exercise, to get
a blank slate, the user ought to be able to just run 'make clean'.
Make it so.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
Junio C Hamano wrote:

> Yes, the last one.  After playing around, with or without COMPUTE/CHECK,
> and then making a final build, it would be nice if "make distclean"
> removed all the intermediate build products without the same special
> "debug build" options (and without COMPUTE, dep_dirs is empty so nothing
> is removed).

Another good idea. :)

 Makefile |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/Makefile b/Makefile
index c939139..93e1a92 100644
--- a/Makefile
+++ b/Makefile
@@ -1693,9 +1693,9 @@ XDIFF_OBJS = xdiff/xdiffi.o xdiff/xprepare.o xdiff/xutils.o xdiff/xemit.o \
 OBJECTS := $(GIT_OBJS) $(XDIFF_OBJS)
 
 dep_files := $(foreach f,$(OBJECTS),$(dir $f).depend/$(notdir $f).d)
+dep_dirs := $(addsuffix .depend,$(sort $(dir $(OBJECTS))))
 
 ifdef COMPUTE_HEADER_DEPENDENCIES
-dep_dirs := $(addsuffix .depend,$(sort $(dir $(OBJECTS))))
 $(dep_dirs):
 	mkdir -p $@
 
-- 
1.7.0.rc1

```