Re: 3DLDF (fwd)

[Alexandre Duret-Lutz]

I don't know CWEB, so my answers may not always make sense.

>>> "Laurence" == Laurence Finston <address@hidden> writes:

[...]

 Laurence> I've written 3DLDF in C++ using CWEB, so my source
 Laurence> files are transfor.web, points.web, etc. When they
 Laurence> are ctangled, they produce transfor.c, points.c,
 Laurence> etc. In addition, ctangle generates header files
 Laurence> transfor.h, points.h, etc., from the CWEB files. CWEB
 Laurence> files that are processed later can depend on header
 Laurence> files generated from CWEB files that were processed
 Laurence> before.

Tools that output multiple files are generally handled 
using rules a-la `bison -d'.

  .y.c:
          bison -d ...
  parser.h: parser.c
  ## Recover from the removal of parser.h
          @if test -f $@; then : else \
             rm -f parser.c; \
             $(MAKE) parser.c; \
          fi

However you need to list all A.h/A.c couples if you do this.

Another possibility is to use a stamp file to represent the
output of the tool.  (Above parser.c was used for this purpose.)

  .web.wstamp:
          $(CTANGLE) $<  # Or whatever the syntax is.

  .wstamp.h:
  ## Recover from the removal of $@
          @if test -f $@; then : else \
             rm -f $<; \
             $(MAKE) $<; \
          fi

  .wstamp.c:
  ## Recover from the removal of $@
          @if test -f $@; then : else \
             rm -f $<; \
             $(MAKE) $<; \
          fi

With the above rules, you should be able to write

  bin_PROGRAMS = foo
  foo_SOURCES = a.web b.web c.web
  BUILT_SOURCES = $(foo_SOURCES:.web=.h)
  DISTCLEANFILES = $(BUILT_SOURCES) $(foo_SOURCES:.web=.c)

Automake knows that .web files can be translated into .wstamp
files and then into .c files, so it will output the rules to
translate .c files into .o files.

The BUILT_SOURCES part ensure that all .h files are built
before .c files get compiled.

[...]

 Laurence> To solve this problem, I've written a second program,
 Laurence> LDF3DCPL, which manages retangling, recompilation,
[...]
 Laurence> It uses diff to determine whether a header file has
 Laurence> changed since its last version, and procedes
 Laurence> accordingly.  

Such a program should replace $(CTANGLES) in the above rules.
Also any renaming from .c to .cxx should be performed there.

[...]

 Laurence> I was unable to call the executables "3DLDF" and
 Laurence> "3DLDFcpl", because the variables (or are they
 Laurence> macros?) "3DLDF_SOURCES" and "3DLDFcpl_SOURCES"
 Laurence> caused errors in Automake.

POSIX call them Makefile macros.  We prefer to talk about
Makefile variables and use the work macro for Autoconf macros.

The errors you have probably indicate you are using Automake 1.4.
Please upgrade.  We are at 1.7.9 now, and the
  foo_SOURCES = a.web b.web c.web
line above assume you have a sufficiently recent version.
-- 
Alexandre Duret-Lutz