Call for volunteer: dwarf2 testing

[Paul Romanyszyn]

Eric Pouech wrote:

> running a 16 bit application from bug Bug 5493
>
>> now gives an a continuous list of 
>> fixme:dbghelp_dwarf:dwarf2_compute_location Unhandled attr op: 75
>> instead of continuous page faulting between on the lookup.
>> What traces do you need and I will add them to that bug.
>>
> does the attached patch help ?
> A+
>
>------------------------------------------------------------------------
>
>>From nobody Mon Sep 17 00:00:00 2001
>From: Eric Pouech <eric.pouech at wanadoo.fr>
>Date: Sat, 1 Jul 2006 11:38:10 +0200
>Subject: [PATCH] [DbgHelp]: dwarf & variable with const values
>
>- properly handle variable with const value (ie without
>  location) in dwarf code
>
>---
>
> dlls/dbghelp/dwarf.c |   10 +++++++---
> 1 files changed, 7 insertions(+), 3 deletions(-)
>
>5d683a5bfdb679fe617ced7b9070756c29d45a85
>diff --git a/dlls/dbghelp/dwarf.c b/dlls/dbghelp/dwarf.c
>index 01250a5..a618986 100644
>--- a/dlls/dbghelp/dwarf.c
>+++ b/dlls/dbghelp/dwarf.c
>@@ -1050,20 +1050,20 @@ static void dwarf2_parse_variable(dwarf2
>                                   dwarf2_debug_info_t* di)
> {
>     struct symt* param_type;
>-    union attribute loc;
>+    union attribute name, loc, value;
>     BOOL is_pmt = di->abbrev->tag == DW_TAG_formal_parameter;
> 
>     TRACE("%s, for %s\n", dwarf2_debug_ctx(subpgm->ctx), dwarf2_debug_di(di));
> 
>     param_type = dwarf2_lookup_type(subpgm->ctx, di);
>-    if (dwarf2_find_attribute(di, DW_AT_location, &loc))
>+    dwarf2_find_name(subpgm->ctx, di, &name, "parameter");
>+    if (dwarf2_find_attribute(di, DW_AT_location, &loc) && loc.block)
>     {
>         union attribute name;
>         union attribute ext;
>         long offset;
>         int in_reg;
> 
>-        dwarf2_find_name(subpgm->ctx, di, &name, "parameter");
>         offset = dwarf2_compute_location(subpgm->ctx, loc.block, &in_reg);
> 	TRACE("found parameter %s/%ld (reg=%d) at %s\n",
>               name.string, offset, in_reg, dwarf2_debug_ctx(subpgm->ctx));
>@@ -1094,6 +1094,10 @@ static void dwarf2_parse_variable(dwarf2
>             break;
>         }
>     }
>+    if (dwarf2_find_attribute(di, DW_AT_const_value, &value))
>+    {
>+        FIXME("NIY (const value %08lx for %s\n", value.uvalue, name.string);
>+    }
>     if (is_pmt && subpgm->func && subpgm->func->type)
>         symt_add_function_signature_parameter(subpgm->ctx->module,
>                                               (struct symt_function_signature*)subpgm->func->type,
>  
>
This app is downloadable and takes only a few steps to reproduce.

Recompiled with that patch using the CFLAGS="$CFLAGS -gdwarf-2" ./configure
and this it the console output

wine: Unhandled page fault on read access to 0x00001d88 at address 
0x18e7:0x000018d2 (thread 0010), starting debugger...
WineDbg starting on pid 0xa
Unhandled exception: page fault on read access to 0x00001d88 in 16-bit 
code (18e7:18d2).
fixme:dbghelp:addr_to_linear Failed to linearize address 101a:00009f0d 
(mode 0)
In 16 bit mode.
Register dump:
 CS:18e7 SS:1b37 DS:191f ES:1a6f FS:003b GS:0033
 IP:18d2 SP:540e BP:5416 FLAGS:0206(   - 00      - RIP1)
 AX:500e BX:5422 CX:0000 DX:0000 SI:0000 DI:1c10
Stack dump:
0x1b37:0x540e:  1c10 0000 18e7 1b37 5485 153b 1a9f 0000
0x1b37:0x541e:  0032 0000 5436 0944 18e7 1270 1ba7 0008
0x1b37:0x542e:  1d5c 0000 0032 1b37 5441 1481 1ab7 0008
0323: sel=191f base=7fe30818 limit=00002d9f 16-bit rw-
034d: sel=1a6f base=7deac750 limit=00001fff 16-bit rw-
fixme:ntdll:RtlNtStatusToDosErrorNoTeb no mapping for c0000119
Backtrace:
=>1 0x18e7:0x18d2 (0x18e7:0x18d2)
  2 0x1a9f:0x153b (0x1a9f:0x153b)
  3 0x101a:0x9f0d (0x101a:0x9f0d)
  4 0x1aef:0x1cdf (0x1aef:0x1cdf)
  5 0x1aef:0x1b9e (0x1aef:0x1b9e)
  6 0x1b17:0x1447 (0x1b17:0x1447)
fixme:dbghelp:elf_load_debug_info_from_map Alpha-support for Dwarf2 
information for kernel32<elf>
fixme:dbghelp_dwarf:dwarf2_compute_location Unhandled attr op: 75
wine: Unhandled page fault on read access to 0x55ac7760 at address 
0x7faba0f8 (thread 0012), starting debugger...
WineDbg starting on pid 0x11
Unhandled exception: page fault on read access to 0x55ac7760 in 32-bit 
code (0x7faba0f8).
fixme:dbghelp:elf_load_debug_info_from_map Alpha-support for Dwarf2 
information for dbghelp<elf>
fixme:dbghelp_dwarf:dwarf2_compute_location Unhandled attr op: 75
wine: Unhandled page fault on read access to 0x55ac7760 at address 
0x7faba0f8 (thread 0014), starting debugger...
WineDbg starting on pid 0x13
Unhandled exception: page fault on read access to 0x55ac7760 in 32-bit 
code (0x7faba0f8).
fixme:dbghelp:elf_load_debug_info_from_map Alpha-support for Dwarf2 
information for dbghelp<elf>
fixme:dbghelp_dwarf:dwarf2_compute_location Unhandled attr op: 75
wine: Unhandled page fault on read access to 0x55ac7760 at address 
0x7faba0f8 (thread 0016), starting debugger...
WineDbg starting on pid 0x15
Unhandled exception: page fault on read access to 0x55ac7760 in 32-bit 
code (0x7faba0f8).
fixme:dbghelp:elf_load_debug_info_from_map Alpha-support for Dwarf2 
information for dbghelp<elf>
fixme:dbghelp_dwarf:dwarf2_compute_location Unhandled attr op: 75
wine: Unhandled page fault on read access to 0x55ac7760 at address 
0x7faba0f8 (thread 0018), starting debugger...
WineDbg starting on pid 0x17
Unhandled exception: page fault on read access to 0x55ac7760 in 32-bit 
code (0x7faba0f8).
....
continues until ctrl C