Re: hbreak.exp: Test hardware breakpoints

["Maciej W. Rozycki" <macro at mips dot com>]

On Sat, 29 Sep 2007, Daniel Jacobowitz wrote:

> Well, that didn't work out as well as I'd hoped.
> 
> Maciej posted a patch to test hardware breakpoints.  It passes on
> i386-linux, using current HEAD GDB.  I wanted to see what would happen
> when the test was run against gdbserver, which does not support
> hardware breakpoints on i386 (yet).  We encountered the long-standing
> bug that nm-i386.h overrides target.h using #define; this means that
> a native i386 GDB incorrectly tries to use ptrace even when connected
> to a remote target.
> 
> I saw two ways to test: build a cross debugger or fix the bug.  I
> fixed the bug.  Unfortunately that broke the test:
> 
> (gdb) hbreak main
> No hardware breakpoint support in the target.
> UNSUPPORTED: gdb.base/hbreak.exp: hardware breakpoints
> 
> This is "target exec", since we have not yet started the program.
> While we were using #define to override GDB's defaults, this worked;
> every target, even exec, claimed to support watchpoints.  Now that
> only "target child" supports hardware watchpoints, you can't insert
> hardware breakpoints before the program is running.
> 
> This is the status quo on other targets too.
> 
> How do you all feel about leaving the hbreak-before-run problem for
> another day, and adjusting the test to start the program running
> before trying hbreak?
> 
> I've attached the patch I used.
> 
> -- 
> Daniel Jacobowitz
> CodeSourcery
> 
> 2007-09-29  Daniel Jacobowitz  <dan@codesourcery.com>
> 
> 	* Makefile.in (i386-nat.o): Update.
> 	* amd64-linux-nat.c (_initialize_amd64_linux_nat): Call
> 	i386_use_watchpoints.
> 	* i386-linux-nat.c (_initialize_i386_linux_nat): Call
> 	i386_use_watchpoints.
> 	* i386-nat.c (i386_stopped_data_address): Take two arguments.
> 	(i386_stopped_by_watchpoint): Update call.
> 	(i386_can_use_hw_breakpoint, i386_use_watchpoints): New.
> 	* config/i386/nm-i386.h: Conditionalize definitions on
> 	! I386_WATCHPOINTS_IN_TARGET_VECTOR.
> 	(i386_use_watchpoints): Declare.
> 	(i386_stopped_data_address): Update.
> 	(CHILD_POST_STARTUP_INFERIOR): Remove obsolete definition.
> 	* config/i386/nm-linux.h (I386_WATCHPOINTS_IN_TARGET_VECTOR): Define.
> 	* config/i386/nm-linux64.h (I386_WATCHPOINTS_IN_TARGET_VECTOR): Define.

 Daniel, have you got any further with this patch you proposed?  I can see 
it has not been included in the tree.

 Here is my gdb.base/hbreak.exp test case again, updated according to your 
suggestion so that hardware breakpoints are only inserted once the target 
has been placed into the execution mode.  It passes on i386-linux natively 
and with the mipsisa32-sde-elf target using the 
mips-sim-sde32/-EB/-march=mips32r2 and mips-sim-sde32/-EL/-march=mips32r2 
boards.  It reports the cases correctly as unsupported on mips-linux 
natively and with the mipsisa32-sde-elf target using the 
mips-sim-sde32/-EB/-march=mips32r2 and mips-sim-sde32/-EL/-march=mips32r2 
boards.

2008-02-27  Maciej W. Rozycki  <macro@mips.com>

	* gdb.base/hbreak.exp: New test for "hbreak" and "thbreak".

 Can you please run it on your gdbserver configuration of concern and then 
let me know if it is OK to apply?

  Maciej

14591.diff
Index: binutils-quilt/src/gdb/testsuite/gdb.base/hbreak.exp
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ binutils-quilt/src/gdb/testsuite/gdb.base/hbreak.exp	2008-02-27 14:34:27.000000000 +0000
@@ -0,0 +1,900 @@
+#   Copyright 1988, 1990, 1991, 1992, 1994, 1995, 1996, 1997, 1998, 1999,
+#   2000, 2002, 2003, 2007, 2008 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/>.
+
+# Please email any bugs, comments, and/or additions to this file to:
+# bug-gdb@prep.ai.mit.edu
+
+# Based on break.exp by Rob Savoye. (rob@cygnus.com)
+# Only one hardware breakpoint is set at a time as targets may limit
+# the number of ones available.
+
+if $tracelevel then {
+    strace $tracelevel
+}
+
+
+#
+# test running programs
+#
+set prms_id 0
+set bug_id 0
+
+set testfile "break"
+set srcfile ${testfile}.c
+set srcfile1 ${testfile}1.c
+set binfile ${objdir}/${subdir}/${testfile}
+
+if  { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}0.o" object {debug nowarnings}] != "" } {
+     untested hbreak.exp
+     return -1
+}
+
+if  { [gdb_compile "${srcdir}/${subdir}/${srcfile1}" "${binfile}1.o" object {debug nowarnings}] != "" } {
+     untested hbreak.exp
+     return -1
+}
+
+if  { [gdb_compile "${binfile}0.o ${binfile}1.o" "${binfile}" executable {debug nowarnings}] != "" } {
+     untested hbreak.exp
+     return -1
+}
+
+if [get_compiler_info ${binfile}] {
+    return -1
+}
+
+gdb_exit
+gdb_start
+gdb_reinitialize_dir $srcdir/$subdir
+gdb_load ${binfile}
+
+if ![runto_main] then {
+    fail "cannot run to main"
+    return
+}
+delete_breakpoints
+
+#
+# Test whether the target supports hardware breakpoints at all.
+#
+send_gdb "hbreak main\n"
+gdb_expect {
+    -re "No hardware breakpoint support in the target.*$" {
+	unsupported "hardware breakpoints"
+	return
+    }
+    -re "Hardware assisted breakpoint.*at.* file .*$srcfile, line.*$" {
+	pass "hardware breakpoint support"
+    }
+    -re ".*$gdb_prompt $" {
+	fail "hardware breakpoint support"
+    }
+    timeout {
+	fail "hardware breakpoint support (timeout)"
+    }
+}
+delete_breakpoints
+
+#
+# Test simple hardware breakpoint setting commands
+#
+
+#
+# test break at function
+#
+gdb_test "hbreak main" \
+    "Hardware assisted breakpoint.*at.* file .*$srcfile, line.*" \
+    "hardware breakpoint function"
+delete_breakpoints
+
+#
+# test break at quoted function
+#
+gdb_test "hbreak \"marker2\"" \
+    "Hardware assisted breakpoint.*at.* file .*$srcfile1, line.*" \
+    "hardware breakpoint quoted function"
+delete_breakpoints
+
+#
+# test break at function in file
+#
+gdb_test "hbreak $srcfile:factorial" \
+    "Hardware assisted breakpoint.*at.* file .*$srcfile, line.*" \
+    "hardware breakpoint function in file"
+delete_breakpoints
+
+set bp_location1 [gdb_get_line_number "set breakpoint 1 here"]
+
+#
+# test break at line number
+#
+# Note that the default source file is the last one whose source text
+# was printed.  For native debugging, before we've executed the
+# program, this is the file containing main, but for remote debugging,
+# it's wherever the processor was stopped when we connected to the
+# board.  So, to be sure, we do a list command.
+#
+gdb_test "list main" \
+    ".*main \\(argc, argv, envp\\).*" \
+    "use `list' to establish default source file"
+gdb_test "hbreak $bp_location1" \
+    "Hardware assisted breakpoint.*at.* file .*$srcfile, line $bp_location1\\." \
+    "hardware breakpoint line number"
+delete_breakpoints
+
+set bp_location2 [gdb_get_line_number "set breakpoint 2 here"]
+
+#
+# test break at line number in file
+#
+gdb_test "hbreak $srcfile:$bp_location2" \
+    "Hardware assisted breakpoint.*at.* file .*$srcfile, line $bp_location2\\." \
+    "hardware breakpoint line number in file"
+delete_breakpoints
+
+set bp_location3 [gdb_get_line_number "set breakpoint 3 here"]
+set bp_location4 [gdb_get_line_number "set breakpoint 4 here"]
+
+#
+# Test putting a break at the start of a multi-line if conditional.
+# Verify the breakpoint was put at the start of the conditional.
+#
+gdb_test "hbreak multi_line_if_conditional" \
+    "Hardware assisted breakpoint.*at.* file .*$srcfile, line $bp_location3\\." \
+    "hardware breakpoint at start of multi line if conditional"
+delete_breakpoints
+
+gdb_test "hbreak multi_line_while_conditional" \
+    "Hardware assisted breakpoint.*at.* file .*$srcfile, line $bp_location4\\." \
+    "hardware breakpoint at start of multi line while conditional"
+
+set bp_location5 [gdb_get_line_number "set breakpoint 5 here"]
+set bp_location6 [gdb_get_line_number "set breakpoint 6 here"]
+
+#
+# check to see what breakpoints are set
+#
+if [target_info exists gdb_stub] {
+    set main_line $bp_location5
+} else {
+    set main_line $bp_location6
+}
+
+if {$hp_aCC_compiler} {
+    set proto "\\(int\\)"
+} else {
+    set proto ""
+}
+
+set bp_location7 [gdb_get_line_number "set breakpoint 7 here"]
+set bp_location8 [gdb_get_line_number "set breakpoint 8 here" $srcfile1]
+set bp_location9 [gdb_get_line_number "set breakpoint 9 here" $srcfile1]
+
+gdb_test "info break" \
+    "Num     Type\[ \]+Disp Enb Address\[ \]+What.*
+\[0-9\]+\[\t \]+hw breakpoint  keep y.* in multi_line_while_conditional at .*$srcfile:$bp_location4" \
+    "hardware breakpoint info"
+delete_breakpoints
+
+# FIXME: The rest of this test doesn't work with anything that can't
+# handle arguments.
+# Huh? There doesn't *appear* to be anything that passes arguments
+# below.
+if [istarget "mips-idt-*"] then {
+    return
+}
+
+#
+# run until the breakpoint at main is hit. For non-stubs-using targets.
+#
+gdb_test "hbreak main" \
+    "Hardware assisted breakpoint.*at.* file .*$srcfile, line.*" \
+    "hardware breakpoint function (2)"
+gdb_run_cmd
+gdb_expect {
+    -re "Breakpoint \[0-9\]+,.*main .*argc.*argv.* at .*$srcfile:$bp_location6.*$bp_location6\[\t \]+if .argc.* \{.*$gdb_prompt $" {
+	pass "run until function breakpoint"
+    }
+    -re "$gdb_prompt $" {
+	fail "run until function breakpoint"
+    }
+    timeout {
+	fail "run until function breakpoint (timeout)"
+    }
+}
+delete_breakpoints
+
+#
+# run until the breakpoint at a line number
+#
+gdb_test "hbreak $bp_location1" \
+    "Hardware assisted breakpoint.*at.* file .*$srcfile, line $bp_location1\\." \
+    "hardware breakpoint line number (2)"
+gdb_test continue "Continuing\\..*Breakpoint \[0-9\]+, main \\(argc=.*, argv=.*, envp=.*\\) at .*$srcfile:$bp_location1.*$bp_location1\[\t \]+printf.*factorial.*" \
+			"run until breakpoint set at a line number"
+delete_breakpoints
+
+#
+# Run until the breakpoint set in a function in a file
+#
+gdb_test "hbreak $srcfile:factorial" \
+    "Hardware assisted breakpoint.*at.* file .*$srcfile, line.*" \
+    "hardware breakpoint function in file (2)"
+for {set i 6} {$i >= 1} {incr i -1} {
+	gdb_test continue "Continuing\\..*Breakpoint \[0-9\]+, factorial \\(value=$i\\) at .*$srcfile:$bp_location7.*$bp_location7\[\t \]+.*if .value > 1. \{.*" \
+			"run until file:function($i) breakpoint"
+}
+delete_breakpoints
+
+#
+# Run until the breakpoint set at a quoted function
+#
+gdb_test "hbreak \"marker2\"" \
+    "Hardware assisted breakpoint.*at.* file .*$srcfile1, line.*" \
+    "hardware breakpoint quoted function (2)"
+gdb_test continue "Continuing\\..*Breakpoint \[0-9\]+, (0x\[0-9a-f\]+ in )?marker2 \\(a=43\\) at .*$srcfile1:($bp_location8|$bp_location9).*" \
+		"run until quoted breakpoint"
+delete_breakpoints
+#
+# run until the file:function breakpoint at a line number in a file
+#
+gdb_test "hbreak $srcfile:$bp_location2" \
+    "Hardware assisted breakpoint.*at.* file .*$srcfile, line $bp_location2\\." \
+    "hardware breakpoint line number in file (2)"
+gdb_test continue "Continuing\\..*Breakpoint \[0-9\]+, main \\(argc=.*, argv=.*, envp=.*\\) at .*$srcfile:$bp_location2.*$bp_location2\[\t \]+argc = \\(argc == 12345\\);.*" \
+		"run until file:linenum breakpoint"
+delete_breakpoints
+
+# Test break at offset +1
+set bp_location10 [gdb_get_line_number "set breakpoint 10 here"]
+
+gdb_test "hbreak +1" \
+    "Hardware assisted breakpoint.*at.* file .*$srcfile, line $bp_location10\\." \
+    "hardware breakpoint offset +1"
+
+# Check to see if breakpoint is hit when stepped onto
+
+gdb_test "step" \
+    ".*Breakpoint \[0-9\]+, main \\(argc=.*, argv=.*, envp=.*\\) at .*$srcfile:$bp_location10.*$bp_location10\[\t \]+return argc;.*breakpoint 10 here.*" \
+    "step onto hardware breakpoint"
+delete_breakpoints
+
+# Check to see if breakpoint can be set on ending brace of function
+set bp_location10a [gdb_get_line_number "set breakpoint 10a here"]
+
+gdb_test "hbreak $bp_location10a" \
+    "Hardware assisted breakpoint.*at.* file .*$srcfile, line $bp_location10a\\." \
+    "setting hardware breakpoint at }"
+
+gdb_test "continue" \
+    ".*Breakpoint \[0-9\]+, main \\(argc=.*, argv=.*, envp=.*\\) at .*$srcfile:$bp_location10a.*$bp_location10a\[\t \]+}.*breakpoint 10a here.*" \
+    "continue to hardware breakpoint at }"
+
+#
+# delete all breakpoints so we can start over, course this can be a test too
+#
+delete_breakpoints
+
+#
+# test temporary breakpoint at function
+#
+
+gdb_test "thbreak main" \
+    "Hardware assisted breakpoint.*at.* file .*$srcfile, line.*" \
+    "temporary hardware breakpoint function"
+delete_breakpoints
+
+#
+# test break at function in file
+#
+
+gdb_test "thbreak $srcfile:factorial" \
+    "Hardware assisted breakpoint.*at.* file .*$srcfile, line.*" \
+    "temporary hardware breakpoint function in file"
+delete_breakpoints
+
+#
+# test break at line number
+#
+send_gdb "thbreak $bp_location1\n"
+gdb_expect {
+    -re "Hardware assisted breakpoint.*at.* file .*$srcfile, line $bp_location1.*$gdb_prompt $" {
+	pass "temporary hardware breakpoint line number #1"
+    }
+    -re ".*$gdb_prompt $" {
+	fail "temporary hardware breakpoint line number #1"
+    }
+    timeout {
+	fail "temporary hardware breakpoint line number #1 (timeout)"
+    }
+}
+delete_breakpoints
+
+gdb_test "thbreak $bp_location6" \
+    "Hardware assisted breakpoint.*at.* file .*$srcfile, line $bp_location6.*" \
+    "temporary hardware breakpoint line number #2"
+delete_breakpoints
+
+#
+# test break at line number in file
+#
+send_gdb "thbreak $srcfile:$bp_location2\n"
+gdb_expect {
+    -re "Hardware assisted breakpoint.*at.* file .*$srcfile, line $bp_location2.*$gdb_prompt $" {
+	pass "temporary hardware breakpoint line number in file #1"
+    }
+    -re ".*$gdb_prompt $" {
+	fail "temporary hardware breakpoint line number in file #1"
+    }
+    timeout {
+	fail "temporary hardware breakpoint line number in file #1 (timeout)"
+    }
+}
+delete_breakpoints
+
+set bp_location11 [gdb_get_line_number "set breakpoint 11 here"]
+gdb_test "thbreak $srcfile:$bp_location11" \
+    "Hardware assisted breakpoint.*at.* file .*$srcfile, line $bp_location11.*" \
+    "temporary hardware breakpoint line number in file #2"
+
+#
+# check to see what breakpoints are set (temporary this time)
+#
+gdb_test "info break" "Num     Type.*Disp Enb Address.*What.*\[\r\n\]
+\[0-9\]+\[\t \]+hw breakpoint  del.*y.*in main at .*$srcfile:$bp_location11.*" \
+    "temporary hardware breakpoint info"
+
+
+#***********
+
+if ![runto_main] then {
+    fail "cannot run to main"
+    return
+}
+delete_breakpoints
+
+# Verify that GDB responds gracefully when asked to set a breakpoint
+# on a nonexistent source line.
+#
+send_gdb "hbreak 999\n"
+gdb_expect {
+    -re "No line 999 in file .*$gdb_prompt $" {
+	pass "hardware break on non-existent source line"
+    }
+    -re "$gdb_prompt $" {
+	fail "hardware break on non-existent source line"
+    }
+    timeout {
+	fail "(timeout) hardware break on non-existent source line"
+    }
+}
+
+# Run to the desired default location. If not positioned here, the
+# tests below don't work.
+#
+gdb_test "until $bp_location1" "main .* at .*:$bp_location1.*" "until bp_location1"
+
+
+# Verify that GDB allows one to just say "break", which is treated
+# as the "default" breakpoint.  Note that GDB gets cute when printing
+# the informational message about other breakpoints at the same
+# location.  We'll hit that bird with this stone too.
+#
+send_gdb "hbreak\n"
+gdb_expect {
+    -re "Hardware assisted breakpoint \[0-9\]*.*$gdb_prompt $" {
+	pass "hardware break on default location"
+    }
+    -re "$gdb_prompt $" {
+	fail "hardware break on default location"
+    }
+    timeout {
+	fail "(timeout) hardware break on default location, 1st time"
+    }
+}
+
+# Verify that a "silent" breakpoint can be set, and that GDB is indeed
+# "silent" about its triggering.
+#
+if ![runto_main] then {
+    fail "cannot run to main"
+    return
+}
+delete_breakpoints
+
+send_gdb "hbreak $bp_location1\n"
+gdb_expect {
+    -re "Hardware assisted breakpoint (\[0-9\]*) at .*, line $bp_location1.*$gdb_prompt $" {
+	pass "set to-be-silent hardware break bp_location1"
+    }
+    -re "$gdb_prompt $" {
+	fail "set to-be-silent hardware break bp_location1"
+    }
+    timeout {
+	fail "(timeout) set to-be-silent break bp_location1"
+    }
+}
+
+send_gdb "commands $expect_out(1,string)\n"
+send_gdb "silent\n"
+send_gdb "end\n"
+gdb_expect {
+    -re ".*$gdb_prompt $" {
+	pass "set silent hardware break bp_location1"
+    }
+    timeout {
+	fail "(timeout) set silent hardware break bp_location1"
+    }
+}
+
+send_gdb "info break $expect_out(1,string)\n"
+gdb_expect {
+    -re "\[0-9\]*\[ \t\]*hw breakpoint.*:$bp_location1\r\n\[ \t\]*silent.*$gdb_prompt $" {
+	pass "info silent hardware break bp_location1"
+    }
+    -re "$gdb_prompt $" {
+	fail "info silent hardware break bp_location1"
+    }
+    timeout {
+	fail "(timeout) info silent hardware break bp_location1"
+    }
+}
+send_gdb "continue\n"
+gdb_expect {
+    -re "Continuing.\r\n$gdb_prompt $" {
+	pass "hit silent hardware break bp_location1"
+    }
+    -re "$gdb_prompt $" {
+	fail "hit silent hardware break bp_location1"
+    }
+    timeout {
+	fail "(timeout) hit silent hardware break bp_location1"
+    }
+}
+send_gdb "bt\n"
+gdb_expect {
+    -re "#0  main .* at .*:$bp_location1.*$gdb_prompt $" {
+	pass "stopped for silent hardware break bp_location1"
+    }
+    -re "$gdb_prompt $" {
+	fail "stopped for silent hardware break bp_location1"
+    }
+    timeout {
+	fail "(timeout) stopped for hardware silent break bp_location1"
+    }
+}
+
+# Verify that GDB can at least parse a breakpoint with the
+# "thread" keyword.  (We won't attempt to test here that a
+# thread-specific breakpoint really triggers appropriately.
+# The gdb.threads subdirectory contains tests for that.)
+#
+set bp_location12 [gdb_get_line_number "set breakpoint 12 here"]
+send_gdb "hbreak $bp_location12 thread 999\n"
+gdb_expect {
+    -re "Unknown thread 999.*$gdb_prompt $" {
+	pass "thread-specific hardware breakpoint on non-existent thread disallowed"
+    }
+    -re "$gdb_prompt $" {
+	fail "thread-specific hardware breakpoint on non-existent thread disallowed"
+    }
+    timeout {
+	fail "(timeout) thread-specific hardware breakpoint on non-existent thread disallowed"
+    }
+}
+send_gdb "hbreak $bp_location12 thread foo\n"
+gdb_expect {
+    -re "Junk after thread keyword..*$gdb_prompt $" {
+	pass "thread-specific hardware breakpoint on bogus thread ID disallowed"
+    }
+    -re "$gdb_prompt $" {
+	fail "thread-specific hardware breakpoint on bogus thread ID disallowed"
+    }
+    timeout {
+	fail "(timeout) thread-specific hardware breakpoint on bogus thread ID disallowed"
+    }
+}
+
+# Verify that GDB responds gracefully to a breakpoint command with
+# trailing garbage.
+#
+send_gdb "hbreak $bp_location12 foo\n"
+gdb_expect {
+    -re "Junk at end of arguments..*$gdb_prompt $" {
+	pass "hardware breakpoint with trailing garbage disallowed"
+    }
+    -re "$gdb_prompt $" {
+	fail "hardware breakpoint with trailing garbage disallowed"
+    }
+    timeout {
+	fail "(timeout) hardware breakpoint with trailing garbage disallowed"
+    }
+}
+
+# Verify that GDB responds gracefully to a "clear" command that has
+# no matching breakpoint.  (First, get us off the current source line,
+# which we know has a breakpoint.)
+#
+send_gdb "next\n"
+gdb_expect {
+    -re ".*$gdb_prompt $" {
+	pass "step over hardware breakpoint"
+    }
+    timeout {
+	fail "(timeout) step over hardware breakpoint"
+    }
+}
+send_gdb "clear 81\n"
+gdb_expect {
+    -re "No breakpoint at 81..*$gdb_prompt $" {
+	pass "clear line has no breakpoint disallowed"
+    }
+    -re "$gdb_prompt $" {
+	fail "clear line has no breakpoint disallowed"
+    }
+    timeout {
+	fail "(timeout) clear line has no breakpoint disallowed"
+    }
+}
+send_gdb "clear\n"
+gdb_expect {
+    -re "No breakpoint at this line..*$gdb_prompt $" {
+	pass "clear current line has no breakpoint disallowed"
+    }
+    -re "$gdb_prompt $" {
+	fail "clear current line has no breakpoint disallowed"
+    }
+    timeout {
+	fail "(timeout) clear current line has no breakpoint disallowed"
+    }
+}
+delete_breakpoints
+
+# Verify that a breakpoint can be set via a convenience variable.
+#
+send_gdb "set \$foo=$bp_location11\n"
+gdb_expect {
+    -re "$gdb_prompt $" {
+	pass "set convenience variable \$foo to bp_location11"
+    }
+    timeout {
+	fail "(timeout) set convenience variable \$foo to bp_location11"
+    }
+}
+send_gdb "hbreak \$foo\n"
+gdb_expect {
+    -re "Hardware assisted breakpoint (\[0-9\]*) at .*, line $bp_location11.*$gdb_prompt $" {
+	pass "set hardware breakpoint via convenience variable"
+    }
+    -re "$gdb_prompt $" {
+	fail "set hardware breakpoint via convenience variable"
+    }
+    timeout {
+	fail "(timeout) set hardware breakpoint via convenience variable"
+    }
+}
+delete_breakpoints
+
+# Verify that GDB responds gracefully to an attempt to set a
+# breakpoint via a convenience variable whose type is not integer.
+#
+send_gdb "set \$foo=81.5\n"
+gdb_expect {
+    -re "$gdb_prompt $" {
+	pass "set convenience variable \$foo to 81.5"
+    }
+    timeout {
+	fail "(timeout) set convenience variable \$foo to 81.5"
+    }
+}
+send_gdb "hbreak \$foo\n"
+gdb_expect {
+    -re "Convenience variables used in line specs must have integer values..*$gdb_prompt $" {
+	pass "set hardware breakpoint via non-integer convenience variable disallowed"
+    }
+    -re "$gdb_prompt $" {
+	fail "set hardware breakpoint via non-integer convenience variable disallowed"
+    }
+    timeout {
+	fail "(timeout) set hardware breakpoint via non-integer convenience variable disallowed"
+    }
+}
+
+# Verify that we can set and trigger a breakpoint in a user-called function.
+#
+send_gdb "hbreak marker2\n"
+gdb_expect {
+    -re "Hardware assisted breakpoint (\[0-9\]*) at .*, line ($bp_location8|$bp_location9).*$gdb_prompt $" {
+	pass "set hardware breakpoint on to-be-called function"
+    }
+    -re "$gdb_prompt $" {
+	fail "set hardware breakpoint on to-be-called function"
+    }
+    timeout {
+	fail "(timeout) set hardware breakpoint on to-be-called function"
+    }
+}
+send_gdb "print marker2(99)\n"
+gdb_expect {
+    -re "The program being debugged stopped while in a function called from GDB.\r\nWhen the function .marker2$proto. is done executing, GDB will silently\r\nstop .instead of continuing to evaluate the expression containing\r\nthe function call...*$gdb_prompt $" {
+	pass "hit hardware breakpoint on called function"
+    }
+    -re "$gdb_prompt $" {
+	fail "hit hardware breakpoint on called function"
+    }
+    timeout {
+	fail "(timeout) hit hardware breakpoint on called function"
+    }
+}
+
+# As long as we're stopped (breakpointed) in a called function,
+# verify that we can successfully backtrace & such from here.
+#
+send_gdb "bt\n"
+gdb_expect {
+    -re "#0\[ \t\]*($hex in )?marker2.*:($bp_location8|$bp_location9)\r\n#1.*_sr4export.*$gdb_prompt $" {
+	pass "backtrace while in called function"
+    }
+    -re "#0\[ \t\]*($hex in )?marker2.*:($bp_location8|$bp_location9)\r\n#1.*function called from gdb.*$gdb_prompt $" {
+	pass "backtrace while in called function"
+    }
+    -re "$gdb_prompt $" {
+	fail "backtrace while in called function"
+    }
+    timeout {
+	fail "(timeout) backtrace while in called function"
+    }
+}
+
+# Return from the called function.  For remote targets, it's important to do
+# this before runto_main, which otherwise may silently stop on the dummy
+# breakpoint inserted by GDB at the program's entry point.
+#
+send_gdb "finish\n"
+gdb_expect {
+    -re "Run till exit from .*marker2.* at .*($bp_location8|$bp_location9)\r\n.* in _sr4export.*$gdb_prompt $" {
+	pass "finish from called function"
+    }
+    -re "Run till exit from .*marker2.* at .*($bp_location8|$bp_location9)\r\n.*function called from gdb.*$gdb_prompt $" {
+	pass "finish from called function"
+    }
+    -re "Run till exit from .*marker2.* at .*($bp_location8|$bp_location9)\r\n.*Value returned.*$gdb_prompt $" {
+	pass "finish from called function"
+    }
+    -re "$gdb_prompt $" {
+	fail "finish from called function"
+    }
+    timeout {
+	fail "(timeout) finish from called function"
+    }
+}
+
+#********
+
+
+#
+# Test "next" over recursive function call.
+#
+
+proc test_next_with_recursion {} {
+    global gdb_prompt
+    global decimal
+    global binfile
+
+    gdb_test "kill" "" "kill program" "Kill the program being debugged.*y or n. $" "y"
+    delete_breakpoints
+
+    if ![runto_main] then {
+	fail "cannot run to main"
+	return
+    }
+    delete_breakpoints
+
+    gdb_test "hbreak factorial" \
+	"Hardware assisted breakpoint $decimal at .*" \
+	"hardware break at factorial"
+
+    # Run until we call factorial with 6
+
+    gdb_run_cmd
+    gdb_expect {
+	-re "Break.* factorial .value=6. .*$gdb_prompt $" {}
+	-re ".*$gdb_prompt $" {
+	    fail "run to factorial(6)";
+	    gdb_suppress_tests;
+	}
+	timeout {
+	    fail "run to factorial(6) (timeout)";
+	    gdb_suppress_tests;
+	}
+    }
+
+    # Continue until we call factorial recursively with 5.
+
+    if [gdb_test "continue" \
+	"Continuing.*Break.* factorial .value=5. .*" \
+	"continue to factorial(5)"] then { gdb_suppress_tests }
+
+    # Do a backtrace just to confirm how many levels deep we are.
+
+    if [gdb_test "backtrace" \
+	"#0\[ \t\]+ factorial .value=5..*" \
+	"backtrace from factorial(5)"] then { gdb_suppress_tests }
+
+    # Now a "next" should position us at the recursive call, which
+    # we will be performing with 4.
+
+    if [gdb_test "next" \
+	".* factorial .value - 1.;.*" \
+	"next to recursive call"] then { gdb_suppress_tests }
+
+    # Disable the breakpoint at the entry to factorial by deleting them all.
+    # The "next" should run until we return to the next line from this
+    # recursive call to factorial with 4.
+    # Buggy versions of gdb will stop instead at the innermost frame on
+    # the line where we are trying to "next" to.
+
+    delete_breakpoints
+
+    if [istarget "mips*tx39-*"] {
+	set timeout 60
+    }
+    # We used to set timeout here for all other targets as well.  This
+    # is almost certainly wrong.  The proper timeout depends on the
+    # target system in use, and how we communicate with it, so there
+    # is no single value appropriate for all targets.  The timeout
+    # should be established by the Dejagnu config file(s) for the
+    # board, and respected by the test suite.
+    #
+    # For example, if I'm running GDB over an SSH tunnel talking to a
+    # portmaster in California talking to an ancient 68k board running
+    # a crummy ROM monitor (a situation I can only wish were
+    # hypothetical), then I need a large timeout.  But that's not the
+    # kind of knowledge that belongs in this file.
+
+    gdb_test next "\[0-9\]*\[\t \]+return \\(value\\);.*" \
+	    "next over recursive call"
+
+    # OK, we should be back in the same stack frame we started from.
+    # Do a backtrace just to confirm.
+
+    set result [gdb_test "backtrace" \
+	    "#0\[ \t\]+ factorial .value=120.*\r\n#1\[ \t\]+ \[0-9a-fx\]+ in factorial .value=6..*" \
+	    "backtrace from factorial(5.1)"]
+    if { $result != 0 } { gdb_suppress_tests }
+
+    if [target_info exists gdb,noresults] { gdb_suppress_tests }
+    gdb_continue_to_end "recursive next test"
+    gdb_stop_suppressing_tests;
+}
+
+test_next_with_recursion
+
+
+#********
+
+# build a new file with optimization enabled so that we can try breakpoints
+# on targets with optimized prologues
+
+set binfileo2 ${objdir}/${subdir}/${testfile}o2
+
+if  { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}O0.o" object {debug nowarnings optimize=-O2}] != "" } {
+     untested hbreak.exp
+     return -1
+}
+
+if  { [gdb_compile "${srcdir}/${subdir}/${srcfile1}" "${binfile}O1.o" object {debug nowarnings optimize=-O2}] != "" } {
+     untested hbreak.exp
+     return -1
+}
+
+if  { [gdb_compile "${binfile}O0.o ${binfile}O1.o" "${binfileo2}" executable {debug nowarnings}] != "" } {
+     untested hbreak.exp
+     return -1
+}
+
+if [get_compiler_info ${binfileo2}] {
+    return -1
+}
+
+gdb_exit
+gdb_start
+gdb_reinitialize_dir $srcdir/$subdir
+gdb_load ${binfileo2}
+
+if ![runto_main] then {
+    fail "cannot run to main"
+    return
+}
+delete_breakpoints
+
+#
+# test break at function
+#
+gdb_test "hbreak main" \
+    "Hardware assisted breakpoint.*at.* file .*, line.*" \
+    "hardware breakpoint function, optimized file"
+
+#
+# run until the breakpoint at main is hit. For non-stubs-using targets.
+#
+gdb_run_cmd
+gdb_expect {
+    -re "Breakpoint \[0-9\]+,.*main .*argc.*argv.* at .*$srcfile:$bp_location6.*$bp_location6\[\t \]+if .argc.* \{.*$gdb_prompt $" {
+	pass "run until function breakpoint, optimized file"
+    }
+    -re "Breakpoint \[0-9\]+,.*main .*argc.*argv.* at .*$gdb_prompt $" {
+	pass "run until function breakpoint, optimized file (code motion)"
+    }
+    -re "$gdb_prompt $" {
+	fail "run until function breakpoint, optimized file"
+    }
+    timeout {
+	fail "run until function breakpoint, optimized file (timeout)"
+    }
+}
+delete_breakpoints
+
+#
+# test break at function
+#
+gdb_test "hbreak marker4" \
+    "Hardware assisted breakpoint.*at.* file .*$srcfile1, line.*" \
+    "hardware breakpoint small function, optimized file"
+
+#
+# run until the breakpoint at a small function
+#
+
+#
+# Add a second pass pattern.  The behavior differs here between stabs
+# and dwarf for one-line functions.  Stabs preserves two line symbols
+# (one before the prologue and one after) with the same line number,
+# but dwarf regards these as duplicates and discards one of them.
+# Therefore the address after the prologue (where the breakpoint is)
+# has no exactly matching line symbol, and GDB reports the breakpoint
+# as if it were in the middle of a line rather than at the beginning.
+
+set bp_location13 [gdb_get_line_number "set breakpoint 13 here" $srcfile1]
+set bp_location14 [gdb_get_line_number "set breakpoint 14 here" $srcfile1]
+send_gdb "continue\n"
+gdb_expect {
+    -re "Breakpoint $decimal, marker4 \\(d=177601976\\) at .*$srcfile1:$bp_location13\[\r\n\]+$bp_location13\[\t \]+void marker4.*" {
+	pass "run until breakpoint set at small function, optimized file"
+    }
+    -re "Breakpoint $decimal, $hex in marker4 \\(d=177601976\\) at .*$srcfile1:$bp_location13\[\r\n\]+$bp_location13\[\t \]+void marker4.*" {
+	pass "run until breakpoint set at small function, optimized file"
+    }
+    -re "Breakpoint $decimal, marker4 \\(d=177601976\\) at .*$srcfile1:$bp_location14\[\r\n\]+$bp_location14\[\t \]+void marker4.*" {
+	# marker4() is defined at line 46 when compiled with -DPROTOTYPES
+	pass "run until breakpoint set at small function, optimized file (line bp_location14)"
+    }
+    -re ".*$gdb_prompt " {
+	fail "run until breakpoint set at small function, optimized file"
+    }
+    timeout {
+	fail "run until breakpoint set at small function, optimized file (timeout)"
+    }
+}
+
+
+# Reset the default arguments for VxWorks
+if [istarget "*-*-vxworks*"] {
+    set timeout 10
+    verbose "Timeout is now $timeout seconds" 2
+    send_gdb "set args main\n"
+    gdb_expect -re ".*$gdb_prompt $" {}
+}