This is the mail archive of the
gdb-patches@sources.redhat.com
mailing list for the GDB project.
[rfa] set processing_current_prefix properly (PR gdb/1520)
- From: David Carlton <carlton at kealia dot com>
- To: gdb-patches at sources dot redhat dot com
- Cc: Elena Zannoni <ezannoni at redhat dot com>, Jim Blandy <jimb at redhat dot com>, Daniel Jacobowitz <drow at mvista dot com>, Michael Elizabeth Chastain<mec at shout dot net>
- Date: Mon, 19 Jan 2004 14:43:04 -0800
- Subject: [rfa] set processing_current_prefix properly (PR gdb/1520)
This is a fix for PR gdb/1520, a namespace problem with GCC 3.4. The
problem was that, if we have this situation:
namespace N {
void foo() { }
}
then the compiler I had been using generated dies as following in its
DWARF 2 output:
1: DW_TAG_namespace:
2: DW_TAG_subprogram:
// Definition of N::foo
whereas GCC head does:
1: DW_TAG_namespace:
2: DW_TAG_subprogram:
// Declaration for N::foo
3: DW_TAG_subprogram:
DW_AT_specification: reference to die #2
// Definition of N::foo.
So I've added code to notice if a die representing a function's
definition has a specification located elsewhere; if so, it looks at
that specification to discover the current enclosing class/namespace.
(Probably there are other places where we need to do this; hopefully,
after a bit more experience, we'll find a less ad-hoc way of handling
this issue.)
It also fixes an inconsistency in my last patch - I had tried to
maintain the invariant that processing_current_prefix was always
non-NULL (i.e. was an actual string, albeit possibly an empty one),
but I was using determine_prefix in ways that violated that invariant.
Tested on i686-pc-linux-gnu, DWARF 2, with GCC 3.2, GCC 3.2 +
DW_TAG_namespace patch, GCC 2.95.3, and GCC head. No regressions;
fixes lots of FAILs in gdb.cp/namespace.exp with GCC head. (From now
on, I'll probably stop testing with my patched GCC 3.2 and switch to
using a GCC snapshot generating DW_TAG_namespace, so I don't miss
problems like this.)
Okay to commit?
David Carlton
carlton@kealia.com
2004-01-19 David Carlton <carlton@kealia.com>
Patch for PR c++/1520:
* dwarf2read.c (read_func_scope): Set processing_current_prefix
properly if we have a specification die.
(possibly_determine_prefix): Rename from determine_prefix.
(determine_prefix): Like the old determine_prefix, but never
returns NULL.
Index: dwarf2read.c
===================================================================
RCS file: /cvs/src/src/gdb/dwarf2read.c,v
retrieving revision 1.122
diff -u -p -r1.122 dwarf2read.c
--- dwarf2read.c 17 Jan 2004 05:35:47 -0000 1.122
+++ dwarf2read.c 19 Jan 2004 20:20:13 -0000
@@ -774,6 +774,8 @@ static void read_type_die (struct die_in
static char *determine_prefix (struct die_info *die);
+static char *possibly_determine_prefix (struct die_info *die);
+
static char *typename_concat (const char *prefix, const char *suffix);
static char *class_name (struct die_info *die);
@@ -2180,6 +2182,8 @@ read_func_scope (struct die_info *die, s
struct die_info *child_die;
struct attribute *attr;
char *name;
+ const char *previous_prefix = processing_current_prefix;
+ struct cleanup *back_to = NULL;
name = dwarf2_linkage_name (die);
@@ -2188,6 +2192,18 @@ read_func_scope (struct die_info *die, s
if (name == NULL || !dwarf2_get_pc_bounds (die, &lowpc, &highpc, cu))
return;
+ if (cu_language == language_cplus)
+ {
+ struct die_info *spec_die = die_specification (die);
+
+ if (spec_die != NULL)
+ {
+ char *specification_prefix = determine_prefix (spec_die);
+ processing_current_prefix = specification_prefix;
+ back_to = make_cleanup (xfree, specification_prefix);
+ }
+ }
+
lowpc += baseaddr;
highpc += baseaddr;
@@ -2238,6 +2254,10 @@ read_func_scope (struct die_info *die, s
symbols go in the file symbol list. */
if (outermost_context_p ())
list_in_scope = &file_symbols;
+
+ processing_current_prefix = previous_prefix;
+ if (back_to != NULL)
+ do_cleanups (back_to);
}
/* Process all the DIES contained within a lexical block scope. Start
@@ -5942,12 +5962,23 @@ read_type_die (struct die_info *die, str
do_cleanups (back_to);
}
+/* Return the name of the namespace/class that DIE is defined within,
+ or "" if we can't tell. The caller should xfree the result. */
+
+static char *
+determine_prefix (struct die_info *die)
+{
+ char *prefix = possibly_determine_prefix (die);
+
+ return prefix ? prefix : xstrdup ("");
+}
+
/* Return the name of the namespace/class that DIE is defined
within, or NULL if we can't tell. The caller should xfree the
result. */
static char *
-determine_prefix (struct die_info *die)
+possibly_determine_prefix (struct die_info *die)
{
struct die_info *parent;
@@ -5962,7 +5993,7 @@ determine_prefix (struct die_info *die)
}
else
{
- char *parent_prefix = determine_prefix (parent);
+ char *parent_prefix = possibly_determine_prefix (parent);
char *retval;
switch (parent->tag) {