Attached suggestion patch how to deal with the most common "errno" symbol
for the most common under-ggdb3 compiled programs.
+Original patch hooked into target_translate_tls_address. But its inferior
+call invalidates `struct frame *' in the callers - RH BZ 690908.
2007-11-03 Jan Kratochvil <jan.kratochvil@redhat.com>
<81a2> DW_AT_name : (indirect string, offset: 0x280e): __errno_location
<81a8> DW_AT_MIPS_linkage_name: (indirect string, offset: 0x2808): *__GI___errno_location
-Index: gdb-6.8.50.20090802/gdb/gdbtypes.c
-===================================================================
---- gdb-6.8.50.20090802.orig/gdb/gdbtypes.c 2009-08-03 09:50:57.000000000 +0200
-+++ gdb-6.8.50.20090802/gdb/gdbtypes.c 2009-08-03 15:42:51.000000000 +0200
-@@ -3769,6 +3769,9 @@ gdbtypes_post_init (struct gdbarch *gdba
- = arch_type (gdbarch, TYPE_CODE_INTERNAL_FUNCTION, 0,
- "<internal function>");
-
-+ builtin_type->nodebug_text_symbol_errno_location
-+ = lookup_function_type (lookup_pointer_type (builtin_type->builtin_int));
-+
- return builtin_type;
- }
-
-Index: gdb-6.8.50.20090802/gdb/gdbtypes.h
-===================================================================
---- gdb-6.8.50.20090802.orig/gdb/gdbtypes.h 2009-08-03 09:50:57.000000000 +0200
-+++ gdb-6.8.50.20090802/gdb/gdbtypes.h 2009-08-03 15:40:02.000000000 +0200
-@@ -1128,6 +1128,8 @@ struct builtin_type
-
- /* This type is used to represent a GDB internal function. */
- struct type *internal_fn;
-+
-+ struct type *nodebug_text_symbol_errno_location;
- };
-
- /* Return the type table for the specified architecture. */
-Index: gdb-6.8.50.20090802/gdb/parse.c
-===================================================================
---- gdb-6.8.50.20090802.orig/gdb/parse.c 2009-08-03 09:50:57.000000000 +0200
-+++ gdb-6.8.50.20090802/gdb/parse.c 2009-08-03 15:41:54.000000000 +0200
-@@ -510,7 +510,11 @@ write_exp_msymbol (struct minimal_symbol
- case mst_text:
- case mst_file_text:
- case mst_solib_trampoline:
-- write_exp_elt_type (objfile_type (objfile)->nodebug_text_symbol);
-+ if (builtin_type (gdbarch)->nodebug_text_symbol_errno_location != NULL
-+ && strcmp (SYMBOL_LINKAGE_NAME (msymbol), "__errno_location") == 0)
-+ write_exp_elt_type (builtin_type (gdbarch)->nodebug_text_symbol_errno_location);
-+ else
-+ write_exp_elt_type (objfile_type (objfile)->nodebug_text_symbol);
- break;
+--- a/gdb/printcmd.c
++++ b/gdb/printcmd.c
+@@ -967,6 +967,8 @@ print_command_1 (char *exp, int inspect, int voidprint)
- case mst_data:
-Index: gdb-6.8.50.20090802/gdb/target.c
-===================================================================
---- gdb-6.8.50.20090802.orig/gdb/target.c 2009-08-03 12:38:47.000000000 +0200
-+++ gdb-6.8.50.20090802/gdb/target.c 2009-08-03 12:49:33.000000000 +0200
-@@ -933,6 +933,25 @@ pop_all_targets (int quitting)
- pop_all_targets_above (dummy_stratum, quitting);
- }
-
-+static int
-+resolve_errno (void *arg)
-+{
-+ CORE_ADDR *arg_addr = arg;
-+ struct expression *expr;
-+ struct cleanup *old_chain = 0;
-+ struct value *val;
-+
-+ expr = parse_expression ("__errno_location()");
-+ old_chain = make_cleanup (free_current_contents, &expr);
-+ val = evaluate_expression (expr);
-+ *arg_addr = value_as_address (val);
-+ release_value (val);
-+ value_free (val);
-+ do_cleanups (old_chain);
-+
-+ return 1;
-+}
-+
- /* Using the objfile specified in OBJFILE, find the address for the
- current thread's thread-local storage with offset OFFSET. */
- CORE_ADDR
-@@ -1023,7 +1042,28 @@ target_translate_tls_address (struct obj
- /* It wouldn't be wrong here to try a gdbarch method, too; finding
- TLS is an ABI-specific thing. But we don't do that yet. */
- else
-- error (_("Cannot find thread-local variables on this target"));
-+ {
-+ struct minimal_symbol *msymbol;
-+
-+ msymbol = lookup_minimal_symbol ("errno", NULL, NULL);
-+ if (msymbol != NULL
-+ && SYMBOL_VALUE_ADDRESS (msymbol) == offset
-+ && (SYMBOL_OBJ_SECTION (msymbol)->objfile == objfile
-+ || (objfile->separate_debug_objfile != NULL
-+ && SYMBOL_OBJ_SECTION (msymbol)->objfile
-+ == objfile->separate_debug_objfile)
-+ || (objfile->separate_debug_objfile_backlink != NULL
-+ && SYMBOL_OBJ_SECTION (msymbol)->objfile
-+ == objfile->separate_debug_objfile_backlink)))
-+ {
-+ if (!catch_errors (resolve_errno, (void *) &addr, "",
-+ RETURN_MASK_ALL))
-+ error (_("TLS symbol `errno' not resolved for non-TLS program."
-+ " You should compile the program with `gcc -pthread'."));
-+ }
-+ else
-+ error (_("Cannot find thread-local variables on this target"));
-+ }
-
- return addr;
- }
-Index: gdb-6.8.50.20090802/gdb/testsuite/gdb.dwarf2/dw2-errno.c
+ if (exp && *exp)
+ {
++ if (strcmp (exp, "errno") == 0)
++ exp = "*((int *(*) (void)) __errno_location) ()";
+ expr = parse_expression (exp);
+ old_chain = make_cleanup (free_current_contents, &expr);
+ cleanup = 1;
+Index: gdb-7.2/gdb/testsuite/gdb.dwarf2/dw2-errno.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
-+++ gdb-6.8.50.20090802/gdb/testsuite/gdb.dwarf2/dw2-errno.c 2009-08-03 12:49:33.000000000 +0200
++++ gdb-7.2/gdb/testsuite/gdb.dwarf2/dw2-errno.c 2011-03-29 10:55:35.000000000 +0200
@@ -0,0 +1,28 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+
+ return 0; /* breakpoint */
+}
-Index: gdb-6.8.50.20090802/gdb/testsuite/gdb.dwarf2/dw2-errno.exp
+Index: gdb-7.2/gdb/testsuite/gdb.dwarf2/dw2-errno.exp
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
-+++ gdb-6.8.50.20090802/gdb/testsuite/gdb.dwarf2/dw2-errno.exp 2009-08-03 12:49:33.000000000 +0200
-@@ -0,0 +1,67 @@
++++ gdb-7.2/gdb/testsuite/gdb.dwarf2/dw2-errno.exp 2011-03-29 10:55:35.000000000 +0200
+@@ -0,0 +1,60 @@
+# Copyright 2007 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
-+if $tracelevel then {
-+ strace $tracelevel
-+}
-+
-+set prms_id 0
-+set bug_id 0
-+
+set testfile dw2-errno
+set srcfile ${testfile}.c
+set binfile ${objdir}/${subdir}/${testfile}