Things have definitely improved.  After applying sum1.diff (I'm running Fedora, which is not a Debian derivative), I was able to build gpc configured as follows:

SRCDIR=../gcc-4.3.5
$SRCDIR/configure --program-suffix=-4.3.5 --disable-shared \
                  --enable-languages=pascal --disable-multilib \
                  --disable-mapped-location

But when running "make check", I get the following:

cc -DHAVE_CONFIG_H -g -O2 -I.. -I../../../gcc-4.3.5/libiberty/testsuite/../../include  -o test-demangle \
../../../gcc-4.3.5/libiberty/testsuite/test-demangle.c ../libiberty.a
../../../gcc-4.3.5/libiberty/testsuite/test-demangle.c:49:1: error: conflicting types for ‘getline’
   49 | getline(buf)
      | ^~~~~~~
In file included from ../../../gcc-4.3.5/libiberty/testsuite/test-demangle.c:26:
/usr/include/stdio.h:616:18: note: previous declaration of ‘getline’ was here
  616 | extern __ssize_t getline (char **__restrict __lineptr,
      |                  ^~~~~~~
../../../gcc-4.3.5/libiberty/testsuite/test-demangle.c: In function ‘protect_end’:
../../../gcc-4.3.5/libiberty/testsuite/test-demangle.c:105:21: warning: implicit declaration of function ‘getpagesize’ [-Wimplicit-function-declaration]
  105 |   size_t pagesize = getpagesize();
 
Cause for concern?

I am going to go ahead and install and see if I can build SAV.

John L. Ries
26215 197th Ave. SE
Covington, WA  98042
(435) 867-8885


On Sat, May 16, 2020 at 6:34 AM Waldek Hebisch <hebisch@math.uni.wroc.pl> wrote:
On Sun, May 10, 2020 at 07:18:01PM -0700, John Ries wrote:
> The error messages are:
>
> ../../gcc-4.3.5/gcc/toplev.c:545:1: error: redefinition of ???floor_log2???
>   545 | floor_log2 (unsigned HOST_WIDE_INT x)
>       | ^~~~~~~~~~
> In file included from ../../gcc-4.3.5/gcc/toplev.c:58:
> ../../gcc-4.3.5/gcc/toplev.h:177:1: note: previous definition of
> ???floor_log2??? wa
> s here
>   177 | floor_log2 (unsigned HOST_WIDE_INT x)
>       | ^~~~~~~~~~
> ../../gcc-4.3.5/gcc/toplev.c:580:1: error: redefinition of ???exact_log2???
>   580 | exact_log2 (unsigned HOST_WIDE_INT x)
>       | ^~~~~~~~~~
> In file included from ../../gcc-4.3.5/gcc/toplev.c:58:
> ../../gcc-4.3.5/gcc/toplev.h:183:1: note: previous definition of
> ???exact_log2??? wa
> s here
>   183 | exact_log2 (unsigned HOST_WIDE_INT x)
>       | ^~~~~~~~~~
>
> There is probably a GCC flag to allow such duplicate definitions, but I
> haven't found it yet (apparently, it isn't -Wnoduplicate-decl-specifier).
> I'm using the GCC 4.3.5 codebase and building with GCC 9.3.1 under Fedora
> 31 (x86_64).
>
> I'm running configure as follows:
>
> SRCDIR=../gcc-4.3.5
> export CFLAGS ="-fkeep-inline-functions -W -Wall -Wwrite-strings \
>                 -Wstrict-prototypes -Wmissing-prototypes \
>                 -Wold-style-definition -Wmissing-format-attribute \
>                 -pedantic -Wno-long-long -Wno-variadic-macros \
>                 -Wno-overlength-strings -fno-common \
>                 -Wnoduplicate-decl-specifier"
>
> $SRCDIR/configure --program-suffix=-4.3.5 --disable-shared \
>                   --enable-languages=pascal
>
> The definition of CFLAGS was my attempt to allow the code to compile.  It
> made no difference.
>
> Any ideas as to how to proceed would be greatly appreciated.

To compile with gcc-4.3.6 on Debian 10 I need two attached patches.
First one fixes to problem above and a few other problems.

The second patch is a gross hack, to work around major breakage
due to changes in Debian.  Namely, Debian moved several critical
files to archtecture specific subdirectories.  For example,
instead of

/usr/lib/crti.o

there is

/usr/lib/x86_64-linux-gnu/crti.o

(or analogous thing for different architecture).  Notably,
compilation of GPC is affected by location of C include files.
If most C include files are in

/usr/include/x86_64-linux-gnu

then your system is affected.  ATM I do not know which distributions
use this scheme and which switched to Debian way.  The
second patch somewhat handles this issue.  It is unstatisfactory,
as it hardcodes 'x86_64-linux-gnu' and there is some (small ???)
breakage when compiling C files (this affects mixed Pascal and C
projects).  Anyway, with both patches applied I can compile
GPC on top of gcc-4.3.6 in Debian 10 using configure line:

../gcc-4.3.6.nn2/configure --enable-languages=c,pascal --disable-multilib --disable-mapped-location

Note that I always compile in directory separate from sources,
that is reason for '../' at the start. '.nn2' suffix is to
indicate that this is patched gcc (with two attached patches and
gcc-4.3.5 patch).


--
                              Waldek Hebisch