gdb/macro-table.diff

137 lines
5.5 KiB
Diff

2007-09-21 Jim Blandy <jimb@codesourcery.com>
* macrotab.h (new_macro_table): Document that removing information
from an obstack/bcache-managed macro table leaks memory.
* macrotab.c (macro_free, macro_bcache_free): Instead of asserting
that data is never freed in obstack/bcache-managed macro tables,
just leak the storage.
(macro_undef): If we're undefining a macro at exactly the same
source location that we defined it, simply remove the definition
altogether.
diff -r 77afe7ffac2f gdb/macrotab.c
--- a/gdb/macrotab.c Fri Sep 21 14:38:59 2007 -0700
+++ b/gdb/macrotab.c Fri Sep 21 17:32:52 2007 -0700
@@ -87,8 +87,14 @@ static void
static void
macro_free (void *object, struct macro_table *t)
{
- gdb_assert (! t->obstack);
- xfree (object);
+ if (t->obstack)
+ /* There are cases where we need to remove entries from a macro
+ table, even when reading debugging information. This should be
+ rare, and there's no easy way to free arbitrary data from an
+ obstack, so we just leak it. */
+ ;
+ else
+ xfree (object);
}
@@ -120,12 +126,18 @@ macro_bcache_str (struct macro_table *t,
/* Free a possibly bcached object OBJ. That is, if the macro table T
- has a bcache, it's an error; otherwise, xfree OBJ. */
+ has a bcache, do nothing; otherwise, xfree OBJ. */
static void
macro_bcache_free (struct macro_table *t, void *obj)
{
- gdb_assert (! t->bcache);
- xfree (obj);
+ if (t->bcache)
+ /* There are cases where we need to remove entries from a macro
+ table, even when reading debugging information. This should be
+ rare, and there's no easy way to free data from a bcache, so we
+ just leak it. */
+ ;
+ else
+ xfree (obj);
}
@@ -781,25 +793,39 @@ macro_undef (struct macro_source_file *s
if (n)
{
- /* This function is the only place a macro's end-of-scope
- location gets set to anything other than "end of the
- compilation unit" (i.e., end_file is zero). So if this macro
- already has its end-of-scope set, then we're probably seeing
- a second #undefinition for the same #definition. */
struct macro_key *key = (struct macro_key *) n->key;
- if (key->end_file)
+ /* If we're removing a definition at exactly the same point that
+ we defined it, then just delete the entry altogether. GCC
+ 4.1.2 will generate DWARF that says to do this if you pass it
+ arguments like '-DFOO -UFOO -DFOO=2'. */
+ if (source == key->start_file
+ && line == key->start_line)
+ splay_tree_remove (source->table->definitions, n->key);
+
+ else
{
- complaint (&symfile_complaints,
- _("macro '%s' is #undefined twice, at %s:%d and %s:%d"), name,
- source->filename, line, key->end_file->filename,
- key->end_line);
+ /* This function is the only place a macro's end-of-scope
+ location gets set to anything other than "end of the
+ compilation unit" (i.e., end_file is zero). So if this
+ macro already has its end-of-scope set, then we're
+ probably seeing a second #undefinition for the same
+ #definition. */
+ if (key->end_file)
+ {
+ complaint (&symfile_complaints,
+ _("macro '%s' is #undefined twice,"
+ " at %s:%d and %s:%d"),
+ name,
+ source->filename, line,
+ key->end_file->filename, key->end_line);
+ }
+
+ /* Whether or not we've seen a prior #undefinition, wipe out
+ the old ending point, and make this the ending point. */
+ key->end_file = source;
+ key->end_line = line;
}
-
- /* Whatever the case, wipe out the old ending point, and
- make this the ending point. */
- key->end_file = source;
- key->end_line = line;
}
else
{
diff -r 77afe7ffac2f gdb/macrotab.h
--- a/gdb/macrotab.h Fri Sep 21 14:38:59 2007 -0700
+++ b/gdb/macrotab.h Fri Sep 21 17:32:52 2007 -0700
@@ -152,15 +152,15 @@ struct macro_source_file
amongst compilation units in an executable file; if BCACHE is zero,
don't cache these things.
- Note that, if either OBSTACK or BCACHE are non-zero, then you
- should only ever add information the macro table --- you should
- never remove things from it. You'll get an error if you try. At
- the moment, since we only provide obstacks and bcaches for macro
- tables for symtabs, this restriction makes a nice sanity check.
- Obstacks and bcaches are pretty much grow-only structures anyway.
- However, if we find that it's occasionally useful to delete things
- even from the symtab's tables, and the storage leak isn't a
- problem, this restriction could be lifted. */
+ Note that, if either OBSTACK or BCACHE are non-zero, then removing
+ information from the table may leak memory. Neither obstacks nor
+ bcaches really allow you to remove information, so although we can
+ update the data structure to record the change, we can't free the
+ old data. At the moment, since we only provide obstacks and
+ bcaches for macro tables for symtabs, this isn't a problem; only
+ odd debugging information makes a definition and then deletes it at
+ the same source location (although 'gcc -DFOO -UFOO -DFOO=2' does
+ do that in GCC 4.1.2.). */
struct macro_table *new_macro_table (struct obstack *obstack,
struct bcache *bcache);