[binutils-gdb] [gdb/testsuite] Fix ERROR in gdb.base/watchpoint-unaligned.exp

[Tom de Vries <vries@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=3c71833c67492ff23bf7f59b25720f06c5a4956f

commit 3c71833c67492ff23bf7f59b25720f06c5a4956f
Author: Tom de Vries <tdevries@suse.de>
Date:   Thu Aug 4 19:54:38 2022 +0200

    [gdb/testsuite] Fix ERROR in gdb.base/watchpoint-unaligned.exp
    
    In PR23888 an error is reported:
    ...
    ERROR: tcl error sourcing watchpoint-unaligned.exp.
    ERROR: expected boolean value but got ""
        while executing
    "if {$wpnum} {
    ...
    
    This presumably happens when:
    - skip_hw_watchpoint_tests returns 0 meaning hw watchpoints are supported
    - gdb fails to set a hw watchpoint and instead sets a sw watchpoint
    
    That particular situation is handled for arm:
    ...
        -re "Watchpoint (\[0-9\]+): .*\r\n$gdb_prompt $" {
            if {[istarget "arm*-*-*"]} {
                untested $test
                set wpnum 0
            }
        }
    ...
    but not for any other targets so wpnum remains "", triggering the ERROR.
    
    Possibly this has been fixed for powerpc by commit 8d4e4d13afb ("gdb Power 9
    add test for HW watchpoint support."), but it's still possible for other
    targets.
    
    Fix this by:
    - initializing wpnum to 0 instead of ""
    - signalling the failure to set a hw watchpoint by a fail
    
    Tested on x86_64-linux, also by adding:
    ...
    gdb_test_no_output "set can-use-hw-watchpoints 0"
    ...
    and verifying that it triggers the fail.
    
    Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=23888

Diff:
---
 gdb/testsuite/gdb.base/watchpoint-unaligned.exp | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/gdb/testsuite/gdb.base/watchpoint-unaligned.exp b/gdb/testsuite/gdb.base/watchpoint-unaligned.exp
index 4dbd3692995..00c6ebcf4eb 100644
--- a/gdb/testsuite/gdb.base/watchpoint-unaligned.exp
+++ b/gdb/testsuite/gdb.base/watchpoint-unaligned.exp
@@ -157,15 +157,17 @@ if ![runto_main] {
 }
 gdb_breakpoint [gdb_get_line_number "final_return"] "Breakpoint $decimal at $hex" "final_return"
 set test {watch data.u.size8twice[1]}
-set wpnum ""
+set wpnum 0
 gdb_test_multiple $test $test {
     -re "Hardware watchpoint (\[0-9\]+): .*\r\n$gdb_prompt $" {
 	set wpnum $expect_out(1,string)
+	pass $gdb_test_name
     }
     -re "Watchpoint (\[0-9\]+): .*\r\n$gdb_prompt $" {
 	if {[istarget "arm*-*-*"]} {
-	    untested $test
-	    set wpnum 0
+	    untested $gdb_test_name
+	} else {
+	    fail $gdb_test_name
 	}
     }
 }