maint.mk: avoid to match non-cast expressions in free calls

[jemarch]

Hi.

While using main.mk in the GNU PDF sources, I found that the rule
matching casts in `free' calls wrongly recognizes constructions like:

    free ((*data)->foo);

as a cast.

The actual regexp used to match a cast is:

     '\<free *\( *\('

I extended it to take care about parenthesized expressions with
following C operators:

     '\<free *\( *\([^\)]+\) *[^ -+*=/%.]'

Strangely enough, that regexp works fine when called from the command
line and from a custom makefile:

-- makefile.foo

C_SOURCES ?= $(shell find . -name '*.[chly]')

all:
        @grep -nE '\<free *\( *\([^\)]+\) *[^ -+*=/%.]' $(C_SOURCES) \
        && { echo foo 1>&2 ; exit 1; } || :

-- end of makefile.foo

But it doesnt work when used in the `sc_cast_of_argument_to_free' in
`maint.mk'.

Executing 

grep -nE '\<free *\( *\([^\)]+\) *[^ -+*=/%.]' ./pdf.c ./pdf.h ./pdf_base.h 
./pdf_obj.c ./pdf_obj.h ./pdf_stm.c ./pdf_stm.h ./pdf_stm_f_a85.c 
./pdf_stm_f_a85.h ./pdf_stm_f_ahex.c ./pdf_stm_f_ahex.h ./pdf_stm_f_flate.c 
./pdf_stm_f_flate.h ./pdf_stm_f_null.c ./pdf_stm_f_null.h ./pdf_stm_f_pred.c 
./pdf_stm_f_pred.h ./pdf_stm_f_rl.c ./pdf_stm_f_rl.h ./pdf_stm_file.c 
./pdf_stm_file.h ./pdf_stm_mem.c ./pdf_stm_mem.h ./pdf_xref.c ./pdf_xref.h 
./pdf_date.h ./pdf_date.c ./pdf_lexer.h ./pdf_rectangle.h ./pdf_rectangle.c 
./pdf_function.h ./pdf_function.c ./pdf_stm_f_fax.h ./pdf_lexer.c 
./pdf_stm_f_fax.c ./pdf_stm_f_lzw.h ./pdf_stm_f_lzw.c ./config.h ./pdf_base.c 
./pdf_parser.c ./pdf_parser.h  &&   \
          { echo 'maint.mk: don'\''t cast free argument' 1>&2;          \
            exit 1; } || :

in the command line also works.

I am somewhat lost :)
     

address@hidden:~/gnu/src/gnulib/build-aux$ cvs diff -u maint.mk
cvs diff: CVS password file /home/jemarch/.cvspass does not exist - creating a 
new file
Index: maint.mk
===================================================================
RCS file: /cvsroot/gnulib/gnulib/build-aux/maint.mk,v
retrieving revision 1.9
diff -u -r1.9 maint.mk
--- maint.mk    6 Aug 2007 14:06:55 -0000       1.9
+++ maint.mk    20 Sep 2007 14:01:37 -0000
@@ -39,7 +39,7 @@
 
 # Casting arguments to free is never necessary.
 sc_cast_of_argument_to_free:
-       @grep -nE '\<free *\( *\(' $(C_SOURCES) &&                      \
+       @grep -nE '\<free *\( *\([^\)]+\) *[^ -+*=/%.]' $(C_SOURCES) && \
          { echo '$(ME): don'\''t cast free argument' 1>&2;             \
            exit 1; } || :