Fix compile warning in symtab.c

My compiler (g++ 8.2) can't tell that *bsc_ptr and *slot_ptr are
only used in the cases when it does get initialized. Just initialize
the vars earlier to avoid the warning, there does not seem to be a
downside to it.

../../gdb/symtab.c: In function ‘block_symbol lookup_static_symbol(const char*, domain_enum)’:
../../gdb/symtab.c:1366:11: warning: ‘slot’ may be used uninitialized in this function [-Wmaybe-uninitialized]
     xfree (slot->value.not_found.name);
     ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../gdb/symtab.c:2578:29: note: ‘slot’ was declared here
   struct symbol_cache_slot *slot;
                             ^~~~
../../gdb/symtab.c:1405:3: warning: ‘bsc’ may be used uninitialized in this function [-Wmaybe-uninitialized]
   if (bsc == NULL)
   ^~
../../gdb/symtab.c:2577:30: note: ‘bsc’ was declared here
   struct block_symbol_cache *bsc;
                              ^~~
../../gdb/symtab.c: In function ‘block_symbol lookup_global_symbol(const char*, const block*, domain_enum)’:
../../gdb/symtab.c:1366:11: warning: ‘slot’ may be used uninitialized in this function [-Wmaybe-uninitialized]
     xfree (slot->value.not_found.name);
     ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../gdb/symtab.c:2658:29: note: ‘slot’ was declared here
   struct symbol_cache_slot *slot;
                             ^~~~
../../gdb/symtab.c:1409:14: warning: ‘bsc’ may be used uninitialized in this function [-Wmaybe-uninitialized]
       ++bsc->collisions;
         ~~~~~^~~~~~~~~~
../../gdb/symtab.c:2657:30: note: ‘bsc’ was declared here
   struct block_symbol_cache *bsc;
                              ^~~

gdb/ChangeLog:

2019-08-22  Christian Biesinger  <cbiesinger@google.com>

	* symtab.c (symbol_cache_lookup): Always initialize *bsc_ptr and *slot_ptr.
This commit is contained in:
Christian Biesinger 2019-08-09 14:25:15 -05:00
parent 6d5554a605
commit d0509ba443
2 changed files with 10 additions and 6 deletions

View File

@ -1,3 +1,8 @@
2019-08-22 Christian Biesinger <cbiesinger@google.com>
* symtab.c (symbol_cache_lookup): Always initialize *bsc_ptr and
*slot_ptr.
2019-08-23 Sergio Durigan Junior <sergiodj@redhat.com>
* configure.ac: Don't check for 'dlfcn.h' (moved to

View File

@ -1297,9 +1297,8 @@ set_symbol_cache_size_handler (const char *args, int from_tty,
The result is the symbol if found, SYMBOL_LOOKUP_FAILED if a previous lookup
failed (and thus this one will too), or NULL if the symbol is not present
in the cache.
If the symbol is not present in the cache, then *BSC_PTR and *SLOT_PTR are
set to the cache and slot of the symbol to save the result of a full lookup
attempt. */
*BSC_PTR and *SLOT_PTR are set to the cache and slot of the symbol, which
can be used to save the result of a full lookup attempt. */
static struct block_symbol
symbol_cache_lookup (struct symbol_cache *cache,
@ -1326,6 +1325,9 @@ symbol_cache_lookup (struct symbol_cache *cache,
hash = hash_symbol_entry (objfile_context, name, domain);
slot = bsc->symbols + hash % bsc->size;
*bsc_ptr = bsc;
*slot_ptr = slot;
if (eq_symbol_entry (slot, objfile_context, name, domain))
{
if (symbol_lookup_debug)
@ -1343,9 +1345,6 @@ symbol_cache_lookup (struct symbol_cache *cache,
/* Symbol is not present in the cache. */
*bsc_ptr = bsc;
*slot_ptr = slot;
if (symbol_lookup_debug)
{
fprintf_unfiltered (gdb_stdlog,