gdb/

Fix internal error on breaking at a multi-locations caller source line.
	* breakpoint.c (parse_breakpoint_sals): Set EXPLICIT_PC for the `break'
	command with no parameters.

gdb/testsuite/
	* gdb.cp/expand-sals.exp, gdb.cp/expand-sals.cc: New.

gdb/ChangeLog

@@ -1,3 +1,9 @@
+2009-05-11  Joel Brobecker <brobecker@adacore.com>
+
+	Fix internal error on breaking at a multi-locations caller source line.
+	* breakpoint.c (parse_breakpoint_sals): Set EXPLICIT_PC for the `break'
+	command with no parameters.
+
 2009-05-11  Pedro Alves  <pedro@codesourcery.com>
 
 	* linux-nat.c (enum sigchld_state): Delete.

gdb/breakpoint.c

@@ -5494,6 +5494,14 @@ parse_breakpoint_sals (char **address,
 	  sal.line = default_breakpoint_line;
 	  sal.symtab = default_breakpoint_symtab;
 	  sal.section = find_pc_overlay (sal.pc);
+
+	  /* "break" without arguments is equivalent to "break *PC" where PC is
+	     the default_breakpoint_address.  So make sure to set
+	     sal.explicit_pc to prevent GDB from trying to expand the list of
+	     sals to include all other instances with the same symtab and line.
+	   */
+	  sal.explicit_pc = 1;
+
 	  sals->sals[0] = sal;
 	  sals->nelts = 1;
 	}

gdb/testsuite/ChangeLog

@@ -1,3 +1,7 @@
+2009-05-11  Jan Kratochvil  <jan.kratochvil@redhat.com>
+
+	* gdb.cp/expand-sals.exp, gdb.cp/expand-sals.cc: New.
+
 2009-04-30  Doug Evans  <dje@google.com>
 
 	* gdb.threads/watchthreads2.exp: New testcase.

gdb/testsuite/gdb.cp/expand-sals.cc

@@ -0,0 +1,53 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright (C) 2009 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+int
+func ()
+{
+  return 42;	/* func-line */
+}
+
+volatile int global_x;
+
+class A
+{
+public:
+  A ()
+    {
+      global_x = func ();	/* caller-line */
+    }
+};
+
+/* class B is here just to make the `func' calling line above having multiple
+   instances - multiple locations.  Template cannot be used as its instances
+   would have different function names which get discarded by GDB
+   expand_line_sal_maybe.  */
+
+class B : public A
+{
+};
+
+int
+main (void)
+{
+  A a;
+  B b;
+
+  return 0;	/* exit-line */
+}

gdb/testsuite/gdb.cp/expand-sals.exp

@@ -0,0 +1,58 @@
+# Copyright 2009 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# 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 { [skip_cplus_tests] } { continue }
+
+set srcfile expand-sals.cc
+if { [prepare_for_testing expand-sals.exp expand-sals $srcfile {debug c++}] } {
+    return -1
+}
+if ![runto_main] {
+    return -1
+}
+
+gdb_breakpoint [gdb_get_line_number "exit-line"]
+
+gdb_breakpoint [gdb_get_line_number "func-line"]
+gdb_continue_to_breakpoint "func" ".*func-line.*"
+
+gdb_test "up" "caller-line.*"
+
+# PC should not be now at the boundary of source lines to make the original bug
+# exploitable.  The GLOBAL_X variable exists in the source for this purpose.
+
+# Original problem was an internal error here.
+set test "break"
+gdb_test_multiple $test $test {
+    -re "Breakpoint \[0-9\]+ at .*, line \[0-9\]+\\. \\(\[2-9\] locations\\)\r\n$gdb_prompt $" {
+	fail $test
+    }
+    -re "Breakpoint \[0-9\]+ at .*, line \[0-9\]+\\.\r\n$gdb_prompt $" {
+	pass $test
+    }
+}
+
+gdb_continue_to_breakpoint "caller" ".*caller-line.*"
+
+# Test GDB caught this return call and not the next one through B::B()
+gdb_test "bt" \
+	 "#0 \[^\r\n\]* A \[^\r\n\]*\r\n#1 \[^\r\n\]* main \[^\r\n\]*" \
+	 "bt from A"
+
+gdb_continue_to_breakpoint "next caller func" ".*func-line.*"
+
+# Verify GDB really could not catch any other breakpoint location.
+
+gdb_continue_to_breakpoint "uncaught return" ".*exit-line.*"