[PATCH 1/4] [gdb/symtab] Fix htab_find_slot call in read_call_site_scope

Tom de Vries via Gdb-patches
2021-10-01T12:33:50Z

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. */
+ /* Address of the first instruction after this call. */

CORE_ADDR pc;

base-commit: e4860c08f990675c9b3535ab18cc7ff21e2a5639
--
2.26.2