Re: [PATCH] GDB64 ppc64 compile error patch

[Kevin Buettner <kevinb at redhat dot com>]

On Wed, 7 Apr 2004 14:37:30 -0500 (CDT)
Manoj Iyer <manjo@austin.ibm.com> wrote:

> 
> This patch fixes compile error when gdb is built as a 64bit binary on a
> PPC64 platform. ELF_NGREG  ELF_NFPREG and ELF_NVRREG are members of an
> enum, but they are also defined in a headerfile, so compiler issues error.
> 
> gcc -c -m64  -mminimal-toc  -I. -I. -I./config
> -DLOCALEDIR="\"/usr/local/share/locale\"" -DHAVE_CONFIG_H
> -I./../include/opcode -I./../readline/.. -I../bfd -I./../bfd
> -I./../include -I../intl -I./../intl  -DMI_OUT=1 -Wimplicit -Wreturn-type
> -Wcomment -Wtrigraphs -Wformat -Wparentheses -Wpointer-arith
> -Wuninitialized -Wformat-nonliteral -Wunused-label -Wunused-function
> ppc-linux-tdep.c
> cc1: warning: -Wuninitialized is not supported without -O
> ppc-linux-tdep.c:956: error: parse error before numeric constant
> make[1]: *** [ppc-linux-tdep.o] Error 1
> make[1]: Leaving directory `/root/manjo/April07/xxx/new/src/gdb'
> make: *** [all-gdb] Error 2
> 
> This is because ELF_NGREG  ELF_NFPREG and ELF_NVRREG are defined in header
> files
> 
> /usr/include/sys/procfs.h:#define ELF_NFPREG      33      /* includes
> fpscr */
> /usr/include/sys/procfs.h:typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
> /usr/include/asm-ppc/elf.h:#define ELF_NFPREG   33      /* includes fpscr
> */
> /usr/include/asm-ppc/elf.h:typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
> /usr/include/asm-ppc64/elf.h:#define ELF_NFPREG 33      /* includes fpscr
> */
> /usr/include/asm-ppc64/elf.h:typedef elf_fpreg_t
> elf_fpregset_t[ELF_NFPREG];
> 
> and the enum
> 
> enum {
>    ELF_NGREG = 48,
>    ELF_NFPREG = 33,
>    ELF_NVRREG = 33
>  };
> 
> causes the compiler to interpret ELF_NFPREG = 33, as 33 = 33, etc.
> 
> The patch attached fixes this error.

Thanks for the patch.  Before I apply it (or make other changes to
avoid the problem), I'd like to have a better understanding of
precisely what is going wrong.

A cursory inspection of the sources doesn't give any clue about how
any of the header files that you mention above are being included in
ppc-linux-tdep.c.  If we could figure out how the offending system
header is being included and prevent its inclusion, we could avoid
redefining the enum constants as macros.  IMO, that would be a
preferable course of action since we don't want system headers
tainting any *-tdep.c code anyway.

Kevin