On 10/1/21 3:09 PM, Simon Marchi wrote:
> 
> 
> On 2021-10-01 08:33, Tom de Vries via Gdb-patches wrote:
>> From: Simon Marchi <simon.marchi@polymtl.ca>
>>
>> In read_call_site_scope we have:
>> ...
>>   call_site_local.pc = pc;
>>   slot = htab_find_slot (cu->call_site_htab, &call_site_local, INSERT);
>> ...
>>
>> The call passes a call_site pointer as element.  OTOH, the hashtab is created
>> using hash_f == core_addr_hash and eq_f == core_addr_eq, so the element
>> will be accessed through a CORE_ADDR pointer.
>>
>> This is not wrong (at least in C), given that pc is the first field in
>> call_site.
>>
>> Nevertheless, as in call_site_for_pc, make the htab_find_slot call match the
>> used hash_f and eq_f by using &pc instead:
>> ...
>>   slot = htab_find_slot (cu->call_site_htab, &pc, INSERT);
>> ...
>>
>> Tested on x86_64-linux.
>>
>> Co-Authored-By: Tom de Vries <tdevries@suse.de>
>> ---
>>  gdb/dwarf2/read.c | 5 ++---
>>  gdb/gdbtypes.h    | 4 +---
>>  2 files changed, 3 insertions(+), 6 deletions(-)
>>
>> diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
>> index 00aa64dd0ab..23870c04e74 100644
>> --- a/gdb/dwarf2/read.c
>> +++ b/gdb/dwarf2/read.c
>> @@ -13341,7 +13341,7 @@ read_call_site_scope (struct die_info *die, struct dwarf2_cu *cu)
>>    struct gdbarch *gdbarch = objfile->arch ();
>>    CORE_ADDR pc, baseaddr;
>>    struct attribute *attr;
>> -  struct call_site *call_site, call_site_local;
>> +  struct call_site *call_site;
>>    void **slot;
>>    int nparams;
>>    struct die_info *child_die;
>> @@ -13369,8 +13369,7 @@ read_call_site_scope (struct die_info *die, struct dwarf2_cu *cu)
>>      cu->call_site_htab = htab_create_alloc_ex (16, core_addr_hash, core_addr_eq,
>>  					       NULL, &objfile->objfile_obstack,
>>  					       hashtab_obstack_allocate, NULL);
>> -  call_site_local.pc = pc;
>> -  slot = htab_find_slot (cu->call_site_htab, &call_site_local, INSERT);
>> +  slot = htab_find_slot (cu->call_site_htab, &pc, INSERT);
>>    if (*slot != NULL)
>>      {
>>        complaint (_("Duplicate PC %s for DW_TAG_call_site "
>> diff --git a/gdb/gdbtypes.h b/gdb/gdbtypes.h
>> index 2a641122aec..84b751e82e3 100644
>> --- a/gdb/gdbtypes.h
>> +++ b/gdb/gdbtypes.h
>> @@ -1783,9 +1783,7 @@ struct call_site_parameter
>>  
>>  struct call_site
>>    {
>> -    /* * Address of the first instruction after this call.  It must be
>> -       the first field as we overload core_addr_hash and core_addr_eq
>> -       for it.  */
> 
> Ah, I had not seen this comment.  So it was on purpose.  Still, I think
> that it makes it more confusing than anything.  The patch LGTM.

And, this follow-up commit reverts everything except the comment.

Any comments?

Thanks,
- Tom