Re: LEX/YACC definitions header

[Alexandre Duret-Lutz]

Hi Alan,

>>> "Alan" == Alan Larkin <address@hidden> writes:

[...]

 Alan> AM_CPPFLAGS = -I"C:/Program Files/Java/j2sdk1.4.1_01/include" 
-I"C:/Program Files/Java/j2sdk1.4.1_01/include/win32"

 Alan> AM_YFLAGS = --defines=$(@:.c++=.hpp) -y

 Alan> lib_LTLIBRARIES = libforrest.la
 Alan> libforrest_la_SOURCES = \
 Alan> ...
 Alan> ForrestLexer.l \
 Alan> ForrestParser.y++ \

[...]

 Alan> ForrestParser.hpp: ForrestParser.y++ # ???

Automake should output this dependency for you.  (But it won't
be called ForrestParser.hpp -- see below).

[...]

 Alan> ForrestLexer.l:7:29: ForrestParser.hpp: No such file or directory
 Alan> [... copious quantities of errors from ForrestLexer.c]

 Alan> How do I write my .am so that ForrestParser.hpp is
 Alan> generated? 

Using the Automake rules to build parsers you can't.  However,
what you can do is to use

AM_YFLAGS = -d

which should produce ForresParser.c++ and ForrestParser.h (not .hpp).

Note that Automake recognizes -d but not --define (the latter
isn't portable anyway).  There is a discussion about using
`AM_YFLAGS = -d' in the manual, don't miss the note about
BUILT_SOURCES.

AFAICT should not need `-y', since this is already added to YACC
by AC_PROG_YACC when needed.


If naming the parser ForrestParser.h instead ForrestParser.hpp
is unacceptable, you can always write your own rule to build it.
I.e.,

Instead of 

  my_SOURCES = ... parser.y ...

Use something like

  my_SOURCES = ... parser.c ...
  EXTRA_DIST = parser.y
  parser.c: parser.y
          $(YACC) ...

etc.


Finally there have been a thread about C++ scanners lately
(no idea if it's your case)
http://sources.redhat.com/ml/automake/2003-02/msg00014.html


 Alan> I define AM_PROG_LEX and AC_PROG_YACC in
 Alan> configure.in. Thats all I need there in order to make the
 Alan> parser right?

Yep.  Generally you should expect Automake to complain when a
macro is missing from configure.ac.  (If you find out it didn't
complain for something, please do complain to address@hidden
If automake find out that you didn't complain because it didn't
complain, it won't complain either -- please don't complain for this.)

 Alan> Also, while I have you, whats the correct way to get rid
 Alan> of that hard coded inclusion of the Java include
 Alan> directory?

You could write a configure check that will fill CPPFLAGS (for
instance using a --with-jave-include option), or let your users
fill CPPFLAGS themselves when they run ./configure.
-- 
Alexandre Duret-Lutz