[binutils-gdb] gdb/testsuite: fix race in gdb.server/multi-ui-errors.exp

[binutils-gdb] gdb/testsuite: fix race in gdb.server/multi-ui-errors.exp

[Andrew Burgess]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=cbd9efbbc0414b71d47020958b5fbeff25504f15

commit cbd9efbbc0414b71d47020958b5fbeff25504f15
Author: Andrew Burgess <aburgess@redhat.com>
Date:   Wed May 24 17:18:52 2023 +0100

    gdb/testsuite: fix race in gdb.server/multi-ui-errors.exp
    
    After this commit:
    
      commit ed32754a8c7919feffc6ddb66ff1c532e4a4d1cd
      Date:   Thu Mar 9 10:45:03 2023 +0100
    
          [gdb/testsuite] Fix gdb.server/multi-ui-errors.exp for remote target
    
    I noticed the occasional failure in gdb.server/multi-ui-errors.exp,
    which looked like this:
    
      (gdb) PASS: gdb.server/multi-ui-errors.exp: interact with GDB's main UI
      interrupt
      (gdb)
      Program received signal SIGINT, Interrupt.
      0x00007ffff7d501e7 in nanosleep () from /lib64/libc.so.6
      FAIL: gdb.server/multi-ui-errors.exp: interrupt (timeout)
      PASS: gdb.server/multi-ui-errors.exp: interrupt arrived
      p server_pid
      $1 = 718174
      (gdb) PASS: gdb.server/multi-ui-errors.exp: p server_pid
    
    This is triggered by this code in gdb.server/multi-ui-errors.exp:
    
        gdb_test "interrupt"
    
        gdb_test_multiple "" "interrupt arrived" {
            -re "Program received signal SIGINT, Interrupt\\.\r\n" {
                pass $gdb_test_name
            }
        }
    
    The problem here is that the first interrupt will trigger the prompt
    to be printed, and then, after some time the inferior will be
    interrupted.
    
    However the default pattern for gdb_test includes a '$' end anchor.
    If expect sees the prompt with nothing following it then everything is
    fine, and the test passes.
    
    However, if the interrupt is quick and so what expect sees is this:
    
      (gdb)
      Program received signal SIGINT, Interrupt.
      0x00007ffff7d501e7 in nanosleep () from /lib64/libc.so.6
    
    In this case the end anchor means that the gdb_test fails to match,
    and eventually times out.
    
    Fix this by passing -no-prompt-anchor to gdb_test.
    
    Reviewed-By: Tom de Vries <tdevries@suse.de>

Diff:
---
 gdb/testsuite/gdb.server/multi-ui-errors.exp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gdb/testsuite/gdb.server/multi-ui-errors.exp b/gdb/testsuite/gdb.server/multi-ui-errors.exp
index af83614fe55..47ded35bc86 100644
--- a/gdb/testsuite/gdb.server/multi-ui-errors.exp
+++ b/gdb/testsuite/gdb.server/multi-ui-errors.exp
@@ -106,7 +106,7 @@ with_spawn_id $gdb_main_spawn_id {
 # Get the gdbserver PID.
 set gdbserver_pid 0
 with_spawn_id $gdb_main_spawn_id {
-    gdb_test "interrupt"
+    gdb_test -no-prompt-anchor "interrupt"
 
     gdb_test_multiple "" "interrupt arrived" {
 	-re "Program received signal SIGINT, Interrupt\\.\r\n" {