Compiling git with makepp patch

  Hi,

getting ready for the release of makepp version 2.0, I'm testing it for 
building various popular open source software.

Git has been giving our promise of Gnu make compatibility a hard time.  I have 
just checked in a series of small fixes, many which were needed to compile 
Git.  This includes things like:

    * accepting an action-prefix of +
    * implementing the cosmetic --no-print-directory directory option, which
      in your usage is essential
    * smarter MAKEFLAGS handling, because you unset it several times, but we
      have more options, some must reach the submake
    * allow special variables like $@ outside of rules — this used to be an error

There are however two things which I can hardly hope to fix:

GIT-VERSION-FILE: FORCE
      @$(SHELL_PATH) ./GIT-VERSION-GEN
-include GIT-VERSION-FILE
.PHONY: FORCE

I don't know why you depend on a phony that has no rule — I also had to make 
that possible.  The file needs to be built immediately so that it can be 
included, before reading the rest of the makefile.  But the dependency is only 
known to be phony after running the rule.  Here you have a hen-egg problem, 
where I have no clue how Gnu make can cope (this is the one case where it 
requires .PHONY).  Anyway, makepp needs the phony declaration before.

The other thing caused me quite a headache before I understood:

PERL_PATH_SQ  = $(subst ','\'',$(PERL_PATH))#'

I suppose you added the comment for Emacs' syntax highlighting, to have an 
even number of unescaped quotes.  The problem is makepp parses this line just 
like Emacs, so it doesn't find the comment, adding in the #' at the point of 
use, which completely screws the sed command.  (You might want to apply my fix 
to a few other makefiles, which have SQ variables, albeit without the syntax 
highlighting workaround, so they are only visually defect.)

coralament / best Grötens / liebe Grüße / best regards / elkorajn salutojn
Daniel Pfeiffer

-- 
lerne / learn / apprends / lär dig / ucz się    Esperanto:
                     http://lernu.net   /http://ikurso.net

Daniel Pfeiffer wrote:

[Attachment: git-makepp.patch]

Please read Documentation/SubmittingPatches for next time.

There are however two things which I can hardly hope to fix:

[...]

PERL_PATH_SQ  = $(subst ','\'',$(PERL_PATH))#'

[...] makepp parses this line just like Emacs, so it doesn't find
the comment, adding in the #' at the point of use, which completely
screws the sed command.

[...]

 # Shell quote;
-bindir_SQ = $(subst ','\'',$(bindir))#'
-gitwebdir_SQ = $(subst ','\'',$(gitwebdir))#'
-gitwebstaticdir_SQ = $(subst ','\'',$(gitwebdir)/static)#'
-SHELL_PATH_SQ = $(subst ','\'',$(SHELL_PATH))#'
-PERL_PATH_SQ  = $(subst ','\'',$(PERL_PATH))#'
-DESTDIR_SQ    = $(subst ','\'',$(DESTDIR))#'
+Q='
+# ' This comment is only to appease IDEs like Emacs.
+# The comment is on a new line, else makepp would see it as a quoted hash.
+bindir_SQ = $(subst $Q,'\'',$(bindir))
+gitwebdir_SQ = $(subst $Q,'\'',$(gitwebdir))
+gitwebstaticdir_SQ = $(subst $Q,'\'',$(gitwebdir)/static)
+SHELL_PATH_SQ = $(subst $Q,'\'',$(SHELL_PATH))
+PERL_PATH_SQ  = $(subst $Q,'\'',$(PERL_PATH))
+DESTDIR_SQ    = $(subst $Q,'\'',$(DESTDIR))

Confusingly, you talk about comments above, but the real issue is that
your makepp apparently gives the ' special meaning.  For once "info
make" and "man 1p make" on my system agree on the semantics of ': none
at all.  From the latter:

  Early proposals stated that an "unquoted" number sign  was  treated  as  the
  start of a comment. The make utility does not pay any attention to quotes. A
  number sign starts a comment regardless of its surroundings.

So can you quote chapter and verse to show that there is anything to
fix?

-- 
Thomas Rast
trast@{inf,student}.ethz.ch

Thomas Rast [off-list ref] writes:

Daniel Pfeiffer wrote:

quoted

[Attachment: git-makepp.patch]

Please read Documentation/SubmittingPatches for next time.

quoted

There are however two things which I can hardly hope to fix:

[...]

quoted

PERL_PATH_SQ  = $(subst ','\'',$(PERL_PATH))#'

[...] makepp parses this line just like Emacs, so it doesn't find
the comment, adding in the #' at the point of use, which completely
screws the sed command.

[...]

quoted

 # Shell quote;
-bindir_SQ = $(subst ','\'',$(bindir))#'
-gitwebdir_SQ = $(subst ','\'',$(gitwebdir))#'
-gitwebstaticdir_SQ = $(subst ','\'',$(gitwebdir)/static)#'
-SHELL_PATH_SQ = $(subst ','\'',$(SHELL_PATH))#'
-PERL_PATH_SQ  = $(subst ','\'',$(PERL_PATH))#'
-DESTDIR_SQ    = $(subst ','\'',$(DESTDIR))#'
+Q='
+# ' This comment is only to appease IDEs like Emacs.
+# The comment is on a new line, else makepp would see it as a quoted hash.
+bindir_SQ = $(subst $Q,'\'',$(bindir))
+gitwebdir_SQ = $(subst $Q,'\'',$(gitwebdir))
+gitwebstaticdir_SQ = $(subst $Q,'\'',$(gitwebdir)/static)
+SHELL_PATH_SQ = $(subst $Q,'\'',$(SHELL_PATH))
+PERL_PATH_SQ  = $(subst $Q,'\'',$(PERL_PATH))
+DESTDIR_SQ    = $(subst $Q,'\'',$(DESTDIR))

Confusingly, you talk about comments above, but the real issue is that
your makepp apparently gives the ' special meaning.  For once "info
make" and "man 1p make" on my system agree on the semantics of ': none
at all.  From the latter:

  Early proposals stated that an "unquoted" number sign  was  treated  as  the
  start of a comment. The make utility does not pay any attention to quotes. A
  number sign starts a comment regardless of its surroundings.

So can you quote chapter and verse to show that there is anything to
fix?

Nevertheless using

  Q='
  SQ='\''
  bindir_SQ = $(subst $Q,$(SQ),$(bindir))

could make substitution more clear ('make' behavior nothwithstanding).

-- 
Jakub Narebski
Poland
ShadeHawk on #git

On Sun, Aug 22, 2010 at 22:31, Daniel Pfeiffer [off-list ref] wrote:

Git has been giving our promise of Gnu make compatibility a hard
time.

Aside from our bugs you can't make that promise if projects like Git
need patches to work with makepp :)

The other thing caused me quite a headache before I understood:

PERL_PATH_SQ  = $(subst ','\'',$(PERL_PATH))#'

I suppose you added the comment for Emacs' syntax highlighting, to have an
even number of unescaped quotes.

That was added by John 'Warthog9' Hawley, I wonder if that also came
with a M-x report-emacs-bug, e.g. cperl-mode deals with that case,
sounds like an easy-to-fix bug in makefile-gmake-mode.

The problem is makepp parses this line
just like Emacs, so it doesn't find the comment, adding in the #' at the
point of use, which completely screws the sed command.  (You might want to
apply my fix to a few other makefiles, which have SQ variables, albeit
without the syntax highlighting workaround, so they are only visually
defect.)

The reason Emacs has issues is because it uses an ad-hoc regexp based
parser that favours speed above correctness for syntax
highlighting.

I'm surprised you've gotten this far with makepp if you don't tokenize
comments and throw their contents away.

Hi,

Daniel Pfeiffer wrote:

.PHONY: FORCE

I don't know why you depend on a phony that has no rule — I also had
to make that possible.

Surely the name explains it. :)

The file needs to be built immediately so
that it can be included, before reading the rest of the makefile.
But the dependency is only known to be phony after running the rule.
Here you have a hen-egg problem, where I have no clue how Gnu make
can cope (this is the one case where it requires .PHONY).

GNU make, unlike, say, pmake, reads all the rules before it runs
anything iirc.  So you can have

 -include foo

 foo:
	echo bar: >foo
	echo '	echo hi' >>foo

and it will cope okay.

Anyway, the git makefile is very far from topologically sorted; if
you are suggesting we change that, that's fine with me, as long as
the new rule is somehow justified and consistent.

Hope that helps,
Jonathan

  la 08/24/2010 06:32 AM Jonathan Nieder skribis:

Hi,

Daniel Pfeiffer wrote:

quoted

The file needs to be built immediately so
that it can be included, before reading the rest of the makefile.
But the dependency is only known to be phony after running the rule.
Here you have a hen-egg problem, where I have no clue how Gnu make
can cope (this is the one case where it requires .PHONY).

GNU make, unlike, say, pmake, reads all the rules before it runs
anything iirc.  So you can have

  -include foo

  foo:
	echo bar:>foo
	echo '	echo hi'>>foo

and it will cope okay.

While that is not the usual use-case for -include, the file might very well 
define some macros, and the rest of the makefile, indeed the foo-rule itself 
might depend on those macros.  Better to have things in a clear order!

Anyway, the git makefile is very far from topologically sorted; if
you are suggesting we change that, that's fine with me, as long as
the new rule is somehow justified and consistent.

coralament / best Grötens / liebe Grüße / best regards / elkorajn salutojn
Daniel Pfeiffer

-- 
lerne / learn / apprends / lär dig / ucz się    Esperanto:
                     http://lernu.net  /  http://ikurso.net

  la 08/23/2010 10:27 PM Ævar Arnfjörð Bjarmason skribis:

On Sun, Aug 22, 2010 at 22:31, Daniel Pfeiffer[off-list ref]  wrote:

quoted

Git has been giving our promise of Gnu make compatibility a hard
time.

Aside from our bugs you can't make that promise if projects like Git
need patches to work with makepp :)

Just two little things in your big makefiles.  The compatibility is just an 
added bonus, we have many other real strengths in makepp.

quoted

The other thing caused me quite a headache before I understood:

PERL_PATH_SQ  = $(subst ','\'',$(PERL_PATH))#'

I suppose you added the comment for Emacs' syntax highlighting, to have an
even number of unescaped quotes.

That was added by John 'Warthog9' Hawley, I wonder if that also came
with a M-x report-emacs-bug, e.g. cperl-mode deals with that case,
sounds like an easy-to-fix bug in makefile-gmake-mode.

Hardly, if you look at my example below!

quoted

The problem is makepp parses this line
just like Emacs, so it doesn't find the comment, adding in the #' at the
point of use, which completely screws the sed command.  (You might want to
apply my fix to a few other makefiles, which have SQ variables, albeit
without the syntax highlighting workaround, so they are only visually
defect.)

The reason Emacs has issues is because it uses an ad-hoc regexp based
parser that favours speed above correctness for syntax
highlighting.

Well, gmake rules are very twisted:  a and b don't do the same thing, because 
file functions shall respect quoting (though to my mind that should then be 
only one funny file name, which gmake gets wrong, splitting it up anyway), and 
c causes gmake to choke:

all: a b
a:
     echo : $(dir 'a # b/c/d') :

B = 'a # b/c/d'
b:
     echo : $(dir $B) :

C = $(dir 'a # b/c/d')
c:
     echo : $C :

I'm surprised you've gotten this far with makepp if you don't tokenize
comments and throw their contents away.

There are a few subtle differences, which mostly don't hurt.

coralament / best Grötens / liebe Grüße / best regards / elkorajn salutojn
Daniel Pfeiffer

-- 
lerne / learn / apprends / lär dig / ucz się    Esperanto:
                     http://lernu.net  /  http://ikurso.net

  la 08/23/2010 09:47 AM Thomas Rast skribis:

Daniel Pfeiffer wrote:

quoted

  # Shell quote;
-bindir_SQ = $(subst ','\'',$(bindir))#'
-gitwebdir_SQ = $(subst ','\'',$(gitwebdir))#'
-gitwebstaticdir_SQ = $(subst ','\'',$(gitwebdir)/static)#'
-SHELL_PATH_SQ = $(subst ','\'',$(SHELL_PATH))#'
-PERL_PATH_SQ  = $(subst ','\'',$(PERL_PATH))#'
-DESTDIR_SQ    = $(subst ','\'',$(DESTDIR))#'
+Q='
+# ' This comment is only to appease IDEs like Emacs.
+# The comment is on a new line, else makepp would see it as a quoted hash.
+bindir_SQ = $(subst $Q,'\'',$(bindir))
+gitwebdir_SQ = $(subst $Q,'\'',$(gitwebdir))
+gitwebstaticdir_SQ = $(subst $Q,'\'',$(gitwebdir)/static)
+SHELL_PATH_SQ = $(subst $Q,'\'',$(SHELL_PATH))
+PERL_PATH_SQ  = $(subst $Q,'\'',$(PERL_PATH))
+DESTDIR_SQ    = $(subst $Q,'\'',$(DESTDIR))

Confusingly, you talk about comments above, but the real issue is that
your makepp apparently gives the ' special meaning.  For once "info
make" and "man 1p make" on my system agree on the semantics of ': none
at all.  From the latter:

   Early proposals stated that an "unquoted" number sign  was  treated  as  the
   start of a comment. The make utility does not pay any attention to quotes. A
   number sign starts a comment regardless of its surroundings.

If you look at the example I just sent to Ævar, that contains examples of how 
crazy the situation really is in gmake.  What you cite here is wrong!

So can you quote chapter and verse to show that there is anything to
fix?

Well, I pointed you to makepp, which is subtly different from gmake, which you 
could.  If you choose not to use it, please yourself!

coralament / best Grötens / liebe Grüße / best regards / elkorajn salutojn
Daniel Pfeiffer

-- 
lerne / learn / apprends / lär dig / ucz się    Esperanto:
                     http://lernu.net  /  http://ikurso.net