dbghelp: merge dwarf code from ntdll/signal_x86_64.c

[Eric Pouech]

André Hentschel a écrit :
> thanks Eric Pouech for the reviews
> ---
>  dlls/dbghelp/dwarf.c |  229 +++++++++++++++++++++++++++++++++++++++++---------
>  dlls/dbghelp/dwarf.h |   15 ++++
>  2 files changed, 204 insertions(+), 40 deletions(-)
>
> diff --git a/dlls/dbghelp/dwarf.c b/dlls/dbghelp/dwarf.c
> index 48e6351..d7f4f50 100644
> --- a/dlls/dbghelp/dwarf.c
> +++ b/dlls/dbghelp/dwarf.c
> @@ -241,6 +241,13 @@ static DWORD64 dwarf2_get_u8(const unsigned char* ptr)
>      return *(const UINT64*)ptr;
>  }
>  
> +static DWORD64 dwarf2_parse_u8(dwarf2_traverse_context_t* ctx)
> +{
> +    unsigned long uvalue = dwarf2_get_u8(ctx->data);
> +    ctx->data += 8;
> +    return uvalue;
> +}
> +
>  static unsigned long dwarf2_get_leb128_as_unsigned(const unsigned char* ptr, const unsigned char** end)
>  {
>      unsigned long ret = 0;
> @@ -344,6 +351,58 @@ static unsigned long dwarf2_parse_addr(dwarf2_traverse_context_t* ctx)
>      return ret;
>  }
>  
> +static ULONG_PTR dwarf2_get_ptr( const unsigned char **p, unsigned char encoding, unsigned word_size)
> +{
> +    ULONG_PTR base;
> +
> +    if (encoding == DW_EH_PE_omit) return 0;
> +
> +    switch (encoding & 0xf0)
> +    {
> +    case DW_EH_PE_abs:
> +        base = 0;
> +        break;
> +    case DW_EH_PE_pcrel:
> +        base = (ULONG_PTR)*p;
>   
I'm afraid I've got some further comments
this is wrong, as it implies that the underlying ELF section (relative 
to p) is mapped at same address between the process dbghelp is working 
on (it has been mapped by the ELF loader) and where dbghelp has mapped 
some ELF sections (likely in another process)

a proper fix will require some extra work

I've started doing it
So either so you do it properly, or you drop the EH frame support out of 
this patch

A+

-- 
Eric Pouech
"The problem with designing something completely foolproof is to underestimate the ingenuity of a complete idiot." (Douglas Adams)