Go32-v2 native woes

["Pierre Muller" <pierre.muller@ics-cnrs.unistra.fr>]

  There are again internal-error problems
with go32v2 native about registers that are 
not correct.

  Current CVS gives this:

Breakpoint 2 at 0xc485: file ../../src/gdb/cli/cli-cmds.c, line 223.
(top-gdb) set prompt top>
#Note top> is an older gdb that works fine.
top> r ./gdb
Starting program: e:/cygwin/usr/local/src/gdbcvs/djcvsbuild/gdb/gdb.exe
./gdb
GNU gdb (GDB) 7.1.50.20100405-cvs
Copyright (C) 2010 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later
<http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "--host=i586-pc-msdosdjgpp --target=djgpp".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...

Breakpoint 1, internal_error (
    file=0xe6d70 "../../src/gdb/target-descriptions.c", line=1140,
    string=0xe6d55 "%s: Assertion `%s' failed.") at
../../src/gdb/utils.c:1050
1050      va_start (ap, string);
top> bt
#0  internal_error (file=0xe6d70 "../../src/gdb/target-descriptions.c",
    line=1140, string=0xe6d55 "%s: Assertion `%s' failed.")
    at ../../src/gdb/utils.c:1050
#1  0x000e8cf2 in tdesc_use_registers (gdbarch=0x46eda0,
target_desc=0x3ed480,
    early_data=0x46fd90) at ../../src/gdb/target-descriptions.c:1140
#2  0x0013a17c in i386_gdbarch_init (info=..., arches=0x0)
    at ../../src/gdb/i386-tdep.c:6699
#3  0x0004dbd6 in gdbarch_find_by_info (info=...)
    at ../../src/gdb/gdbarch.c:3979
#4  0x00088785 in set_gdbarch_from_file (abfd=0x42c0a0)
    at ../../src/gdb/arch-utils.c:552
#5  0x00017c8b in exec_file_attach (filename=0x3eaeb8 "./gdb", from_tty=1)
    at ../../src/gdb/exec.c:296
#6  0x000256dd in catch_command_errors (command=0x179e7 <exec_file_attach>,
    arg=0x3eaeb8 "./gdb", from_tty=1, mask=6) at
../../src/gdb/exceptions.c:525
#7  0x00002a2a in captured_main (data=0x3ea208) at ../../src/gdb/main.c:808
#8  0x00025649 in catch_errors (func=0x1dfa <captured_main>,
    func_args=0x3ea208, errstring=0x1b94 "", mask=6)
    at ../../src/gdb/exceptions.c:510
#9  0x00002d72 in gdb_main (args=0x3ea208) at ../../src/gdb/main.c:916
#10 0x0000180d in main (argc=2, argv=0x3eaed8) at ../../src/gdb/gdb.c:33
top> f 1
#1  0x000e8cf2 in tdesc_use_registers (gdbarch=0x46eda0,
target_desc=0x3ed480,
    early_data=0x46fd90) at ../../src/gdb/target-descriptions.c:1140
1140      gdb_assert (VEC_length (tdesc_arch_reg, data->arch_regs) <=
num_regs);

top> p num_regs
$1 = 32
top> p *data.arch_regs
$2 = {num = 33, alloc = 36, vec = {{reg = 0x3ed6d8, type = 0x0}}}
top>

  The additional reg in arch_regs seems to come from
i386_validate_tdesc_p function:
 /* Need to include %mxcsr, so add one.  */
   num_regs += tdep->num_xmm_regs + 1;

Adding this condition 
if (tdep->num_xmm_regs)
removes the problem above,
but I get another error later:
Breakpoint 1 at 0x479d: file ../../src/gdb/utils.c, line 1050.
Breakpoint 2 at 0xc485: file ../../src/gdb/cli/cli-cmds.c, line 223.
(top-gdb) start
Temporary breakpoint 3 at 0x17d4: file ../../src/gdb/gdb.c, line 28.
Starting program: e:/cygwin/usr/local/src/gdbcvs/djcvsbuild/gdb/gdb.exe

Temporary breakpoint 3, main (argc=1, argv=0x3eae78) at
../../src/gdb/gdb.c:28
28        memset (&args, 0, sizeof args);
(top-gdb) inf reg
eax            0x10     16
ecx            0x0      0
edx            0x100    256
ebx            0x3f6    1014
esp            0x3ea1f0 0x3ea1f0
ebp            0x3ea220 0x3ea220
esi            0x54     84
edi            0x36a258 3580504
eip            0x17d4   0x17d4 <main+28>
eflags         0x3206   [ PF IF #12 #13 ]
cs             0x28f    655
ss             0x297    663
ds             0x297    663
es             0x297    663
fs             0x2a7    679
gs             0x2a7    679

Breakpoint 1, internal_error (file=0x1286ab "../../src/gdb/go32-nat.c",
    line=546, string=0x128680 "Invalid register no. %d in fetch_register.")
    at ../../src/gdb/utils.c:1050
1050      va_start (ap, string);

  GDB is trying to display register 32 which is normally "xmm0"
and thus should not be displayed for go32v2.
  
  I was not able o fix that second problem :(

Pierre Muller
Pascal language support maintainer for GDB
and old-DOS lover ...