[bug-recutils] portability fixes

[Bruno Haible]

Hi José,

The use of gnulib in recutils-1.0/lib/ indicates that the package is meant to
work also on platforms other than glibc systems, right?

When I try to build it on a MacOS X 10.5 system, I get this error:

libtool: compile:  gcc -DHAVE_CONFIG_H -I. -I../lib 
-DLOCALEDIR=\"/Users/bruno/data/local-macos/share/locale\" -DREMOTE_DESCRIPTORS 
-Wall -I/Users/bruno/data/local-macos/include -Wall -fno-strict-aliasing -g -O2 
-MT rec-field-name.lo -MD -MP -MF .deps/rec-field-name.Tpo -c rec-field-name.c  
-fno-common -DPIC -o .libs/rec-field-name.o
rec-field-name.c:28:20: error: malloc.h: No such file or directory
make[2]: *** [rec-field-name.lo] Error 1

Fix: Change rec-field-name.c to include <stdlib.h> instead of malloc.h.
Likewise for rec-field.c, rec-fex.c, rec-parser.c, rec-record.c, rec-rset.c,
rec-sex.c, rec-writer.c.

Then this error:

libtool: link: gcc -Wall -fno-strict-aliasing -g -O2 -o .libs/recinf recutl.o 
recinf.o  ../lib/.libs/libgnu.a -L/Users/bruno/data/local-macos/lib 
../src/.libs/librec.dylib /Users/bruno/data/local-macos/lib/libintl.dylib 
/Users/bruno/data/local-macos/lib/libiconv.dylib -lc -lcurl
Undefined symbols:
  "_open_memstream", referenced from:
      _recutl_eval_field_expression in recutl.o
ld: symbol(s) not found
collect2: ld returned 1 exit status
make[1]: *** [recinf] Error 1
make: *** [all-recursive] Error 1

This is because the function open_memstream(), and also fmemopen() which is
used in rec-parser.c, exist only on glibc, Cygwin 1.7, and AIX 7.1:

$ ./show-portability open_memstream
libc                aix-7.1.0
libc                cygwin-1.7
libc                glibc-2.3.6
MISSING in          aix-4.3.2 aix-5.1.0 aix-5.2.0 aix-5.3.0a aix-6.1.0 beos 
cygwin-1.5 freebsd-5.2.1 freebsd-6.0 freebsd-6.4 hpux-10.20 hpux-11.00 
hpux-11.11 hpux-11.23 hpux-11.31 interix-3.5 irix-5.3 irix-6.5 macosx-10.3 
macosx-10.4 macosx-10.5 mingw netbsd-3.0 netbsd-5.0.1 netbsd-5.0 nsk-G06 
openbsd-3.8 osf1-4.0d osf1-5.1a pips solaris-2.10 solaris-2.11_2010_11 
solaris-2.4 solaris-2.5.1 solaris-2.6 solaris-2.7 solaris-2.8 solaris-2.9

$ ./show-portability fmemopen
libc                aix-7.1.0
libc                cygwin-1.7
libc                glibc-2.3.6
MISSING in          aix-4.3.2 aix-5.1.0 aix-5.2.0 aix-5.3.0a aix-6.1.0 beos 
cygwin-1.5 freebsd-5.2.1 freebsd-6.0 freebsd-6.4 hpux-10.20 hpux-11.00 
hpux-11.11 hpux-11.23 hpux-11.31 interix-3.5 irix-5.3 irix-6.5 macosx-10.3 
macosx-10.4 macosx-10.5 mingw netbsd-3.0 netbsd-5.0.1 netbsd-5.0 nsk-G06 
openbsd-3.8 osf1-4.0d osf1-5.1a pips solaris-2.10 solaris-2.11_2010_11 
solaris-2.4 solaris-2.5.1 solaris-2.6 solaris-2.7 solaris-2.8 solaris-2.9

See also the gnulib documentation:
http://www.gnu.org/software/gnulib/manual/html_node/open_005fmemstream.html
http://www.gnu.org/software/gnulib/manual/html_node/fmemopen.html

And no, gnulib cannot create a replacement for these functions, because the
'FILE' type is simply not extensible and the stream functions are hardcoded
in many systems.

For open_memstream(), how about using an explicit in-memory buffer, that
is grown through x2nrealloc when needed?

For fmemopen(), I would suggest to change the rec_parser_s type so that
it contains a FILE * for reading from a file and a
'const char *buf; const char *bufend;' for reading from a buffer in memory.

Bruno