Re: [PP?] [PATCH] gdb: z80: Guard against missing symtab in skip_prologue

[Simon Marchi <simark@simark.ca>]

On 6/3/26 8:11 AM, Ronald Hecht wrote:
> |Hi, this is the patch from PR tdep/34198. It fixes an internal
> segmentation fault in z80_skip_prologue when setting "break main" on
> some Z80 binaries. "break *main" works, which points at the
> prologue/SAL path. Regression-tested manually with the reproducer from
> the PR. Thanks, Ronald
> https://sourceware.org/bugzilla/show_bug.cgi?id=34198 |
> diff --git a/gdb/z80-tdep.c b/gdb/z80-tdep.c
> index f7e207d02ec3..f2e9b09e3b91 100644
> --- a/gdb/z80-tdep.c
> +++ b/gdb/z80-tdep.c
> @@ -495,12 +495,17 @@ z80_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc)
>    if (prologue_end != 0)
>      {
>        struct symtab_and_line prologue_sal = find_sal_for_pc (func_addr, 0);
> -      struct compunit_symtab *compunit = prologue_sal.symtab->compunit ();
> -      const char *debug_format = compunit->debugformat ();
> -
> -      if (debug_format != NULL &&
> -         !strncasecmp ("dwarf", debug_format, strlen("dwarf")))
> -       return std::max (pc, prologue_end);
> +      if (prologue_sal.symtab != nullptr)
> +       {
> +         struct compunit_symtab *compunit = prologue_sal.symtab->compunit ();
> +         if (compunit != nullptr)

symtab->compunit() can't return nullptr, so I wouldn't add this check
(that method should be modified to return a reference, to make it
clear).

The patch looks good otherwise.  Would you be ok with me pushing your
patch with that change?

Simon