Re: [PATCH] gdb: restore nullptr check in compunit_symtab::find_call_site

[Tom de Vries <tdevries@suse.de>]

On 12/3/24 16:52, Simon Marchi wrote:
> Commit de2b4ab50de ("Convert dwarf2_cu::call_site_htab to new hash
> table") removed this nullptr check for no good reason.  This causes a
> crash if `m_call_site_htab` is not set, as shown in PR 32410.  My guess
> is that when doing this change, I tried to make `m_call_site_htab` not a
> pointer, removed this check, then realized it wasn't so obvious, and
> forgot to re-add the check.
> 

Hi Simon,

thanks for the quick fix.

I've tested it with the test-case on which the PR was reported, and gdb 
no longer crashes.  The test-case still produces two FAILs, but that 
looks unrelated.

LGTM.

Approved-By: Tom de Vries <tdevries@suse.de>

Thanks,
- Tom

> Change-Id: I455e00cdc0519dfb412dc7826d17a839b77aae69
> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32410
> ---
>   gdb/symtab.c | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/gdb/symtab.c b/gdb/symtab.c
> index edc19ff5c155..30c22dcea38c 100644
> --- a/gdb/symtab.c
> +++ b/gdb/symtab.c
> @@ -396,6 +396,9 @@ linetable_entry::pc (const struct objfile *objfile) const
>   call_site *
>   compunit_symtab::find_call_site (CORE_ADDR pc) const
>   {
> +  if (m_call_site_htab == nullptr)
> +    return nullptr;
> +
>     CORE_ADDR delta = this->objfile ()->text_section_offset ();
>   
>     if (auto it = m_call_site_htab->find (static_cast<unrelocated_addr> (pc - delta));
> 
> base-commit: d556cf2ec79ed5afbbdd523484954c6a520b5b73