[PATCH 6/6] Fix racy output matching in gdb.tui/tui-completion.exp

[PATCH 6/6] Fix racy output matching in gdb.tui/tui-completion.exp

[Pedro Alves]

'make check-read1 TESTS="gdb.tui/tui-completion.exp"' exposes this test race:

  (gdb) PASS: gdb.tui/completion.exp: set max-completions unlimited
  layout ^G
  asm    next   prev   regs   split  src
  (gdb) FAIL: gdb.tui/completion.exp: completion of layout names: tab completion
  Quit
  (gdb) PASS: gdb.tui/completion.exp: completion of layout names: quit command input
  focus ^G
  cmd   next  prev  src
  (gdb) FAIL: gdb.tui/completion.exp: completion of focus command: tab completion
  Quit

This is caused by expecting "$gdb_prompt layout $".
gdb_test_multiple's internal prompt regexp can match first if expect's
internal buffer is filled with partial output.  Fix that by splitting
the gdb_test_multiple in question in two.  Since the same problem/code
appears twice in the file, factor out a common procedure.

gdb/testsuite/ChangeLog:
yyyy-mm-dd  Pedro Alves  <palves@redhat.com>

	* gdb.tui/tui-completion.exp (test_tab_completion): New procedure,
	factored out from ...
	(top level): ... here, and adjusted to avoid expecting beyond the
	prompt in a single gdb_test_multiple.
---
 gdb/testsuite/gdb.tui/completion.exp | 36 +++++++++++++++++-------------------
 1 file changed, 17 insertions(+), 19 deletions(-)

diff --git a/gdb/testsuite/gdb.tui/completion.exp b/gdb/testsuite/gdb.tui/completion.exp
index ac5d5f2..f53a244 100644
--- a/gdb/testsuite/gdb.tui/completion.exp
+++ b/gdb/testsuite/gdb.tui/completion.exp
@@ -22,12 +22,20 @@ if {[skip_tui_tests] || [target_info exists gdb,nointerrupts]} {
 
 gdb_test_no_output "set max-completions unlimited"
 
-with_test_prefix "completion of layout names" {
+# TAB-complete INPUT_LINE, and expect EXPECTED_RE as completion match
+# output.
+proc test_tab_completion {input_line expected_re} {
+    global gdb_prompt
+
     set test "tab completion"
-    send_gdb "layout\t\t\t"
+    send_gdb "$input_line\t\t\t"
     gdb_test_multiple "" "$test" {
-	-re "asm *next *prev *regs *split *src *\r\n$gdb_prompt layout $" {
-	    pass "$test"
+	-re "$expected_re\r\n$gdb_prompt " {
+	    gdb_test_multiple "" "$test" {
+		-re "^$input_line$" {
+		    pass "$test"
+		}
+	    }
 	}
     }
     send_gdb "\003"
@@ -39,20 +47,10 @@ with_test_prefix "completion of layout names" {
     }
 }
 
-with_test_prefix "completion of focus command" {
-    set test "tab completion"
-    send_gdb "focus \t\t"
-    gdb_test_multiple "" "$test" {
-	-re "cmd *next *prev *src *\r\n$gdb_prompt focus $" {
-	    pass "$test"
-	}
-    }
+with_test_prefix "completion of layout names" {
+    test_tab_completion "layout" "asm *next *prev *regs *split *src *"
+}
 
-    send_gdb "\003"
-    set test "quit command input"
-    gdb_test_multiple "" "$test" {
-	-re "$gdb_prompt $" {
-	    pass "$test"
-	}
-    }
+with_test_prefix "completion of focus command" {
+    test_tab_completion "focus" "cmd *next *prev *src *"
 }
-- 
2.5.5

[PATCH 5/6] Fix racy output matching in gdb.base/multi-attach.exp, gdb.server/ext-{attach, restart, ext-run}.exp

[Pedro Alves]

This commit fixes this same problem in several places:

  (gdb) PASS: gdb.multi/multi-attach.exp: backtrace 2
  kill
  Kill the program being debugged? (y or n) y
  (gdb) FAIL: gdb.multi/multi-attach.exp: kill inferior 2 (got interactive prompt)

This is just another case of the gdb_test_multiple's internal "got
interactive prompt" pattern matching because the testcase misses
matching enough.

gdb/testsuite/ChangeLog:
yyyy-mm-dd  Pedro Alves  <palves@redhat.com>

	* gdb.multi/multi-attach.exp ("kill" test): Match the whole query
	output.
	* gdb.server/ext-attach.exp ("kill" test): Likewise.
	* gdb.server/ext-restart.exp ("kill" test): Likewise.
	* gdb.server/ext-run.exp ("kill" test): Likewise.
	* gdb.server/ext-wrapper.exp ("kill" test): Likewise.
---
 gdb/testsuite/gdb.multi/multi-attach.exp | 4 ++--
 gdb/testsuite/gdb.server/ext-attach.exp  | 2 +-
 gdb/testsuite/gdb.server/ext-restart.exp | 2 +-
 gdb/testsuite/gdb.server/ext-run.exp     | 2 +-
 gdb/testsuite/gdb.server/ext-wrapper.exp | 2 +-
 5 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/gdb/testsuite/gdb.multi/multi-attach.exp b/gdb/testsuite/gdb.multi/multi-attach.exp
index 4240ff7..9397f85 100644
--- a/gdb/testsuite/gdb.multi/multi-attach.exp
+++ b/gdb/testsuite/gdb.multi/multi-attach.exp
@@ -51,9 +51,9 @@ gdb_test "attach $testpid2" \
     "attach to program 2"
 gdb_test "backtrace" ".*main.*" "backtrace 2"
 
-gdb_test "kill" "" "kill inferior 2" "Kill the program being debugged.*" "y"
+gdb_test "kill" "" "kill inferior 2" "Kill the program being debugged. .y or n. " "y"
 gdb_test "inferior 1" ".*Switching to inferior 1.*"
-gdb_test "kill" "" "kill inferior 1" "Kill the program being debugged.*" "y"
+gdb_test "kill" "" "kill inferior 1" "Kill the program being debugged. .y or n. " "y"
 
 kill_wait_spawned_process $test_spawn_id1
 kill_wait_spawned_process $test_spawn_id2
diff --git a/gdb/testsuite/gdb.server/ext-attach.exp b/gdb/testsuite/gdb.server/ext-attach.exp
index f3e992a..881c636 100644
--- a/gdb/testsuite/gdb.server/ext-attach.exp
+++ b/gdb/testsuite/gdb.server/ext-attach.exp
@@ -68,7 +68,7 @@ gdb_test "attach $testpid" \
     "attach to remote program 2"
 gdb_test "backtrace" ".*main.*" "backtrace 2"
 
-gdb_test "kill" "" "kill" "Kill the program being debugged.*" "y"
+gdb_test "kill" "" "kill" "Kill the program being debugged. .y or n. " "y"
 gdb_test_no_output "monitor exit"
 
 kill_wait_spawned_process $test_spawn_id
diff --git a/gdb/testsuite/gdb.server/ext-restart.exp b/gdb/testsuite/gdb.server/ext-restart.exp
index 44c9b1f..d28ce47 100644
--- a/gdb/testsuite/gdb.server/ext-restart.exp
+++ b/gdb/testsuite/gdb.server/ext-restart.exp
@@ -60,6 +60,6 @@ with_test_prefix "restart" {
     }
 }
 
-gdb_test "kill" "" "kill" "Kill the program being debugged.*" "y"
+gdb_test "kill" "" "kill" "Kill the program being debugged. .y or n. " "y"
 
 gdb_test_no_output "monitor exit"
diff --git a/gdb/testsuite/gdb.server/ext-run.exp b/gdb/testsuite/gdb.server/ext-run.exp
index cdb1695..d8b3e92 100644
--- a/gdb/testsuite/gdb.server/ext-run.exp
+++ b/gdb/testsuite/gdb.server/ext-run.exp
@@ -61,7 +61,7 @@ if { [istarget *-*-linux*] } {
     }
 }
 
-gdb_test "kill" "" "kill" "Kill the program being debugged.*" "y"
+gdb_test "kill" "" "kill" "Kill the program being debugged. .y or n. " "y"
 
 gdb_load $binfile
 gdb_test "monitor help" "The following monitor commands.*" \
diff --git a/gdb/testsuite/gdb.server/ext-wrapper.exp b/gdb/testsuite/gdb.server/ext-wrapper.exp
index 8b1af7b..b195ae7 100644
--- a/gdb/testsuite/gdb.server/ext-wrapper.exp
+++ b/gdb/testsuite/gdb.server/ext-wrapper.exp
@@ -65,6 +65,6 @@ with_test_prefix "restart" {
     gdb_test "print d" "\\$${decimal} = ${hex} \"1\".*"
 }
 
-gdb_test "kill" "" "kill" "Kill the program being debugged.*" "y"
+gdb_test "kill" "" "kill" "Kill the program being debugged. .y or n. " "y"
 
 gdb_test_no_output "monitor exit"
-- 
2.5.5

[PATCH 4/6] Fix racy output matching in gdb.base/cpcompletion.exp

[Pedro Alves]

With:

 $ make check-read1 TESTS="gdb.cp/cpcompletion.exp"

we get (from gdb.log):

 (gdb) complete break Foo::
 break Foo::Foo()
 break Foo::Foofoo()
 break Foo::get_foo()
 break Foo::set_foo(int)
 break Foo::~Foo()
 (gdb) FAIL: gdb.cp/cpcompletion.exp: complete class methods (Foo not found)

The problem is that the
  "break ${class}::\[A-Za-z0-9_~\]+"
regexp patches partial input, like:
  break Foo::F
  break Foo::Fo
  break Foo::Foo
etc.

Fix that by expecting each whole line.

gdb/testsuite/ChangeLog:
yyyy-mm-dd  Pedro Alves  <palves@redhat.com>

	* gdb.cp/cpcompletion.exp (test_class_complete): Tighten regex to
	match till end of line.
---
 gdb/testsuite/gdb.cp/cpcompletion.exp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gdb/testsuite/gdb.cp/cpcompletion.exp b/gdb/testsuite/gdb.cp/cpcompletion.exp
index d4da1d2..c7883ee 100644
--- a/gdb/testsuite/gdb.cp/cpcompletion.exp
+++ b/gdb/testsuite/gdb.cp/cpcompletion.exp
@@ -26,7 +26,7 @@ proc test_class_complete {class expr name matches} {
     gdb_test_multiple $cmd $name {
 	"break ${class}::main" { fail "$name (saw global symbol)" }
 	$cmd { exp_continue }
-	-re "break ${class}::\[A-Za-z0-9_~\]+" {
+	-re "break ${class}::\[^\r\n\]*\r\n" {
 	    set str $expect_out(0,string)
 	    scan $str "break ${class}::%\[^(\]" method
 	    lappend seen $method
-- 
2.5.5

[PATCH 1/6] Fix racy output matching in gdb.asm/asm-source.exp

[Pedro Alves]

Testing with:
 $ make check-read1 TESTS="gdb.asm/asm-source.exp"

Exposes a testcase bug that can result in racy fails:

 (gdb) PASS: gdb.asm/asm-source.exp: next over foo3
 return
 Make selected stack frame return now? (y or n) y
 n
 #0  main () at /home/pedro/gdb/mygit/src/gdb/testsuite/gdb.asm/asmsrc1.s:53
 53              gdbasm_exit0
 (gdb) FAIL: gdb.asm/asm-source.exp: return from foo2 (got interactive prompt)
 n

The problem is that the "return now\?.*" regex can match partial
output like this:

 "Make selected stack frame return no"

and then we send the 'y' too early, and then the next time around we
hit gdb_test_multiple's internal "got interactive prompt" regex.

Also, note we match "return no" instead of "return now" because the
regex is missing one quote level.

gdb/testsuite/ChangeLog:
yyyy-mm-dd  Pedro Alves  <palves@redhat.com>

	* gdb.asm/asm-source.exp ("kill" test): Match the whole query
	output.  Fix '?' match.
---
 gdb/testsuite/gdb.asm/asm-source.exp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gdb/testsuite/gdb.asm/asm-source.exp b/gdb/testsuite/gdb.asm/asm-source.exp
index 138609a..47717a2 100644
--- a/gdb/testsuite/gdb.asm/asm-source.exp
+++ b/gdb/testsuite/gdb.asm/asm-source.exp
@@ -435,7 +435,7 @@ gdb_test "next" "$line_foo2_leave\[ \t\]+gdbasm_leave" "next over foo3"
 # Like "finish", "return" command also can return to the caller
 # line again or the statement after, depending on the architecture.
 gdb_test_multiple "return" "return from foo2" {
-    -re "Make (foo2|selected stack frame) return now\?.*" {
+    -re "Make (foo2|selected stack frame) return now\\? .y or n. " {
         send_gdb "y\n"
         exp_continue
     }
-- 
2.5.5

[PATCH 2/6] Fix racy output matching in gdb.base/completion.exp

[Pedro Alves]

Testing with:
 $ make check-read1 TESTS="gdb.base/completion.exp"

Exposes a testcase bug that can result in racy fails:

  FAIL: gdb.base/completion.exp: command-name completion limiting using tab character
  ERROR: Undefined command "".
  FAIL: gdb.base/completion.exp: symbol-name completion limiting using tab character
  FAIL: gdb.base/completion.exp: symbol-name completion limiting using complete command

testsuite/gdb.log shows:

  (gdb) PASS: gdb.base/completion.exp: set max-completions 5
  p^G
  passcount     path          print         print-object  printf
  *** List may be truncated, max-completions reached. ***
  (gdb) FAIL: gdb.base/completion.exp: command-name completion limiting using tab character
  pcomplete p
  Undefined command: "pcomplete".  Try "help".
  (gdb) ERROR: Undefined command "".

The problem is that the expect buffer can get filled with partial
output that ends in the gdb prompt, and so the default FAIL inside
gdb_test_multiple matches.

Fix that by splitting the gdb_test_multiple in two stages.  Since that
is done in more than one place in the testcase, move the otherwise
duplicate code to helper procedures.

gdb/testsuite/ChangeLog:
yyyy-mm-dd  Pedro Alves  <palves@redhat.com>

	* gdb.base/completion.exp (ignore_and_resync, test_tab_complete):
	New procedures, factored out from ...
	(top level): ... here, and adjusted to avoid expecting beyond the
	prompt in one go.
---
 gdb/testsuite/gdb.base/completion.exp | 86 ++++++++++++++---------------------
 1 file changed, 34 insertions(+), 52 deletions(-)

diff --git a/gdb/testsuite/gdb.base/completion.exp b/gdb/testsuite/gdb.base/completion.exp
index f03bfc3e..9c7c17a 100644
--- a/gdb/testsuite/gdb.base/completion.exp
+++ b/gdb/testsuite/gdb.base/completion.exp
@@ -863,36 +863,45 @@ gdb_test "complete break $srcfile:ma" "break\.c:main"
 
 gdb_test_no_output "set max-completions 5"
 
-set test "command-name completion limiting using tab character"
-send_gdb "p\t"
-gdb_test_multiple "" "$test" {
-    -re "^p\\\x07$" {
-	send_gdb "\t"
-	gdb_test_multiple "" "$test" {
-	    -re "List may be truncated, max-completions reached.*\r\n$gdb_prompt p$" {
-		# Complete the command and ignore the output to resync
-		# gdb for the next test.
-		send_gdb "\n"
-		gdb_test_multiple "" "$test" {
-		    -re "$gdb_prompt $" {
-			pass "$test"
-		    }
+proc ignore_and_resync {cmd result test} {
+    global gdb_prompt
+
+    gdb_test_multiple "" "$test" {
+	-re "^${cmd}$" {
+	    # Complete the command and ignore the output
+	    # to resync gdb for the next test.
+	    send_gdb "\n"
+	    gdb_test_multiple "" "$test" {
+		-re "$gdb_prompt $" {
+		    $result $test
 		}
 	    }
-	    -re "$gdb_prompt p$" {
-		# Complete the command and ignore the output to resync
-		# gdb for the next test.
-		send_gdb "\n"
-		gdb_test_multiple "" "$test" {
-		    -re "$gdb_prompt $" {
-			fail "$test"
-		    }
+	}
+    }
+}
+
+proc test_tab_complete {cmd test} {
+    global gdb_prompt
+
+    send_gdb "${cmd}\t"
+    gdb_test_multiple "" "$test" {
+	-re "^${cmd}\\\x07$" {
+	    send_gdb "\t"
+	    gdb_test_multiple "" "$test" {
+		-re "List may be truncated, max-completions reached.*\r\n$gdb_prompt " {
+		    ignore_and_resync $cmd pass $test
+		}
+		-re "$gdb_prompt " {
+		    ignore_and_resync $cmd fail $test
 		}
 	    }
-        }
+	}
     }
 }
 
+test_tab_complete "p" \
+    "command-name completion limiting using tab character"
+
 set test "command-name completion limiting using complete command"
 send_gdb "complete p\n"
 gdb_test_multiple "" "$test" {
@@ -903,35 +912,8 @@ gdb_test_multiple "" "$test" {
 
 gdb_test_no_output "set max-completions 3"
 
-set test "symbol-name completion limiting using tab character"
-send_gdb "p marker\t"
-gdb_test_multiple "" "$test" {
-    -re "^p marker\\\x07$" {
-	send_gdb "\t"
-	gdb_test_multiple "" "$test" {
-	    -re "List may be truncated, max-completions reached.*\r\n$gdb_prompt p marker$" {
-		# Complete the command and ignore the output to resync
-		# gdb for the next test.
-		send_gdb "\n"
-		gdb_test_multiple "" "$test" {
-		    -re "$gdb_prompt $" {
-			pass "$test"
-		    }
-		}
-	    }
-	    -re "$gdb_prompt p marker$" {
-		# Complete the command and ignore the output to resync
-		# gdb for the next test.
-		send_gdb "\n"
-		gdb_test_multiple "" "$test" {
-		    -re "$gdb_prompt $" {
-			fail "$test"
-		    }
-		}
-	    }
-        }
-    }
-}
+test_tab_complete "p marker" \
+    "symbol-name completion limiting using tab character"
 
 set test "symbol-name completion limiting using complete command"
 send_gdb "complete p mark\n"
-- 
2.5.5

[PATCH 0/6] Fix several cases of racy output matching

[Pedro Alves]

After <https://sourceware.org/ml/gdb-patches/2017-10/msg00751.html>, I
had the bright idea of running the whole testsuite with "make
check-read1", and that exposed a number of problems.

This fixes a good chunk of those.  (There are more in at least gdb.mi/
and gdb.python/.)

Pedro Alves (6):
  Fix racy output matching in gdb.asm/asm-source.exp
  Fix racy output matching in gdb.base/completion.exp
  Fix racy output matching in gdb.base/memattr.exp
  Fix racy output matching in gdb.base/cpcompletion.exp
  Fix racy output matching in gdb.base/multi-attach.exp,
    gdb.server/ext-{attach, restart, ext-run}.exp
  Fix racy output matching in gdb.tui/tui-completion.exp

 gdb/testsuite/gdb.asm/asm-source.exp     |  2 +-
 gdb/testsuite/gdb.base/completion.exp    | 86 +++++++++++++-------------------
 gdb/testsuite/gdb.base/memattr.exp       | 12 ++---
 gdb/testsuite/gdb.cp/cpcompletion.exp    |  2 +-
 gdb/testsuite/gdb.multi/multi-attach.exp |  4 +-
 gdb/testsuite/gdb.server/ext-attach.exp  |  2 +-
 gdb/testsuite/gdb.server/ext-restart.exp |  2 +-
 gdb/testsuite/gdb.server/ext-run.exp     |  2 +-
 gdb/testsuite/gdb.server/ext-wrapper.exp |  2 +-
 gdb/testsuite/gdb.tui/completion.exp     | 36 +++++++------
 10 files changed, 65 insertions(+), 85 deletions(-)

-- 
2.5.5

[PATCH 3/6] Fix racy output matching in gdb.base/memattr.exp

[Pedro Alves]

Testing with:
 $ make check-read1 TESTS="gdb.base/memattr.exp"


Exposes a testcase bug that can result in racy fails:

  info mem
  Using user-defined memory regions.
  Num Enb Low Addr           High Addr          Attrs
  1   y   0x0000000000601060 0x0000000000601160 wo nocache
  2   y   0x0000000000601180 0x0000000000601280 ro nocache
  4   y   0x0000000000601280 0x0000000000601380 rw nocache
  3   y   0x0000000000601380 0x0000000000601480 rw nocache
  5   y   0x0000000000601480 0x0000000000601580 rw nocache
  (gdb) FAIL: gdb.base/memattr.exp: info mem (1)

The problem is that:

  "Attrs\[^\n\r]*.."

matches:

  "Attrs \r"

when the output buffer is filled with partial output like this:

  "info mem\r\nUsing user-defined memory regions.\r\nNum Enb Low Addr           High Addr          Attrs \r"

gdb/testsuite/ChangeLog:
yyyy-mm-dd  Pedro Alves  <palves@redhat.com>

	* gdb.base/memattr.exp: Tighten regexes to match the end line.
---
 gdb/testsuite/gdb.base/memattr.exp | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/gdb/testsuite/gdb.base/memattr.exp b/gdb/testsuite/gdb.base/memattr.exp
index 48f0496..88eb51c 100644
--- a/gdb/testsuite/gdb.base/memattr.exp
+++ b/gdb/testsuite/gdb.base/memattr.exp
@@ -114,30 +114,30 @@ set see4 0
 set see5 0
 
 set info_mem_header_pattern \
-    "info mem.*Num\[ \t\]+Enb\[ \t\]+Low\[ \t\]+Addr\[ \t\]+High\[ \t\]+Addr\[ \t\]+Attrs\[^\n\r]*.."
+    "info mem.*Num\[ \t\]+Enb\[ \t\]+Low\[ \t\]+Addr\[ \t\]+High\[ \t\]+Addr\[ \t\]+Attrs\[^\r\n\]*\r\n"
 
 gdb_test_multiple "info mem" "info mem(1)" {
     -re ${info_mem_header_pattern} {
 	# Discard the header.
 	exp_continue
     }
-    -re "^1   y  \[ \t\]+$hex $hex wo nocache \[^\r\n\]*.." {
+    -re "^1   y  \[ \t\]+$hex $hex wo nocache \[^\r\n\]*\r\n" {
 	set see1 1
 	exp_continue
     }
-    -re "^2   y  \[ \t\]+$hex $hex ro nocache \[^\r\n\]*.." {
+    -re "^2   y  \[ \t\]+$hex $hex ro nocache \[^\r\n\]*\r\n" {
 	set see2 1
 	exp_continue
     }
-    -re "^3   y  \[ \t\]+$hex $hex rw nocache \[^\r\n\]*.." {
+    -re "^3   y  \[ \t\]+$hex $hex rw nocache \[^\r\n\]*\r\n" {
 	set see3 1
 	exp_continue
     }
-    -re "^4   y  \[ \t\]+$hex $hex rw nocache \[^\r\n\]*.." {
+    -re "^4   y  \[ \t\]+$hex $hex rw nocache \[^\r\n\]*\r\n" {
 	set see4 1
 	exp_continue
     }
-    -re "^5   y  \[ \t\]+$hex $hex rw nocache \[^\r\n\]*.." {
+    -re "^5   y  \[ \t\]+$hex $hex rw nocache \[^\r\n\]*\r\n" {
 	set see5 1
 	exp_continue
     }
-- 
2.5.5

Re: [PATCH 0/6] Fix several cases of racy output matching

[Pedro Alves]

On 10/26/2017 06:42 PM, Pedro Alves wrote:
> After <https://sourceware.org/ml/gdb-patches/2017-10/msg00751.html>, I
> had the bright idea of running the whole testsuite with "make
> check-read1", and that exposed a number of problems.
> 
> This fixes a good chunk of those.  (There are more in at least gdb.mi/
> and gdb.python/.)
> 
> Pedro Alves (6):
>   Fix racy output matching in gdb.asm/asm-source.exp
>   Fix racy output matching in gdb.base/completion.exp
>   Fix racy output matching in gdb.base/memattr.exp
>   Fix racy output matching in gdb.base/cpcompletion.exp
>   Fix racy output matching in gdb.base/multi-attach.exp,
>     gdb.server/ext-{attach, restart, ext-run}.exp
>   Fix racy output matching in gdb.tui/tui-completion.exp

I've pushed these in now.

Thanks,
Pedro Alves

Re: [PATCH 6/6] Fix racy output matching in gdb.tui/tui-completion.exp

[Simon Marchi]

On 2017-10-26 01:42 PM, Pedro Alves wrote:
> 'make check-read1 TESTS="gdb.tui/tui-completion.exp"' exposes this test race:
> 
>   (gdb) PASS: gdb.tui/completion.exp: set max-completions unlimited
>   layout ^G
>   asm    next   prev   regs   split  src
>   (gdb) FAIL: gdb.tui/completion.exp: completion of layout names: tab completion
>   Quit
>   (gdb) PASS: gdb.tui/completion.exp: completion of layout names: quit command input
>   focus ^G
>   cmd   next  prev  src
>   (gdb) FAIL: gdb.tui/completion.exp: completion of focus command: tab completion
>   Quit
> 
> This is caused by expecting "$gdb_prompt layout $".
> gdb_test_multiple's internal prompt regexp can match first if expect's
> internal buffer is filled with partial output.  Fix that by splitting
> the gdb_test_multiple in question in two.  Since the same problem/code
> appears twice in the file, factor out a common procedure.
> 
> gdb/testsuite/ChangeLog:
> yyyy-mm-dd  Pedro Alves  <palves@redhat.com>
> 
> 	* gdb.tui/tui-completion.exp (test_tab_completion): New procedure,
> 	factored out from ...
> 	(top level): ... here, and adjusted to avoid expecting beyond the
> 	prompt in a single gdb_test_multiple.
> ---
>  gdb/testsuite/gdb.tui/completion.exp | 36 +++++++++++++++++-------------------
>  1 file changed, 17 insertions(+), 19 deletions(-)
> 
> diff --git a/gdb/testsuite/gdb.tui/completion.exp b/gdb/testsuite/gdb.tui/completion.exp
> index ac5d5f2..f53a244 100644
> --- a/gdb/testsuite/gdb.tui/completion.exp
> +++ b/gdb/testsuite/gdb.tui/completion.exp
> @@ -22,12 +22,20 @@ if {[skip_tui_tests] || [target_info exists gdb,nointerrupts]} {
>  
>  gdb_test_no_output "set max-completions unlimited"
>  
> -with_test_prefix "completion of layout names" {
> +# TAB-complete INPUT_LINE, and expect EXPECTED_RE as completion match
> +# output.
> +proc test_tab_completion {input_line expected_re} {
> +    global gdb_prompt
> +
>      set test "tab completion"
> -    send_gdb "layout\t\t\t"
> +    send_gdb "$input_line\t\t\t"
>      gdb_test_multiple "" "$test" {
> -	-re "asm *next *prev *regs *split *src *\r\n$gdb_prompt layout $" {
> -	    pass "$test"
> +	-re "$expected_re\r\n$gdb_prompt " {
> +	    gdb_test_multiple "" "$test" {
> +		-re "^$input_line$" {
> +		    pass "$test"
> +		}
> +	    }
>  	}
>      }
>      send_gdb "\003"
> @@ -39,20 +47,10 @@ with_test_prefix "completion of layout names" {
>      }
>  }
>  
> -with_test_prefix "completion of focus command" {
> -    set test "tab completion"
> -    send_gdb "focus \t\t"
> -    gdb_test_multiple "" "$test" {
> -	-re "cmd *next *prev *src *\r\n$gdb_prompt focus $" {
> -	    pass "$test"
> -	}
> -    }
> +with_test_prefix "completion of layout names" {
> +    test_tab_completion "layout" "asm *next *prev *regs *split *src *"
> +}
>  
> -    send_gdb "\003"
> -    set test "quit command input"
> -    gdb_test_multiple "" "$test" {
> -	-re "$gdb_prompt $" {
> -	    pass "$test"
> -	}
> -    }
> +with_test_prefix "completion of focus command" {
> +    test_tab_completion "focus" "cmd *next *prev *src *"
>  }
> 

Hi Pedro,

I am seeing a failure in this test (gdb.tui/completion.exp), I pushed
this patch to fix it.

commit 71774bc994e3f2a09c3b1988dbf2e99b86f53e2e
Author: Simon Marchi <simon.marchi@ericsson.com>
Date:   Wed Nov 15 11:07:02 2017 -0500

    Fix gdb.tui/completion.exp test

    When I run it locally, the test gdb.tui/completion.exp test fails
    because of a timeout:

    Running /home/emaisin/src/binutils-gdb/gdb/testsuite/gdb.tui/completion.exp ...
    FAIL: gdb.tui/completion.exp: completion of layout names: tab completion (timeout)

    The problem seems to be this regex, which confirms that after doing
    layout<TAB>, "layout" is printed again after the gdb prompt:

      -re "^$input_line$"

    The problem is that there's a trailing space in the output after
    "layout".  Since the regex has an anchored end (the $), it doesn't
    match.  Adding a space fixes the test.

    gdb/testsuite/ChangeLog:

    	* gdb.tui/completionn.exp (test_tab_completion): Add space in
    	regex.

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 8c57179..bb8dd79 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2017-11-15  Simon Marchi  <simon.marchi@ericsson.com>
+
+	* gdb.tui/completionn.exp (test_tab_completion): Add space in
+	regex.
+
 2017-11-13  Simon Marchi  <simon.marchi@polymtl.ca>

 	* gdb.opt/inline-locals.exp: Remove trailing parentheses from
diff --git a/gdb/testsuite/gdb.tui/completion.exp b/gdb/testsuite/gdb.tui/completion.exp
index f53a244..426b6bf 100644
--- a/gdb/testsuite/gdb.tui/completion.exp
+++ b/gdb/testsuite/gdb.tui/completion.exp
@@ -32,7 +32,7 @@ proc test_tab_completion {input_line expected_re} {
     gdb_test_multiple "" "$test" {
 	-re "$expected_re\r\n$gdb_prompt " {
 	    gdb_test_multiple "" "$test" {
-		-re "^$input_line$" {
+		-re "^$input_line $" {
 		    pass "$test"
 		}
 	    }

Re: [PATCH 6/6] Fix racy output matching in gdb.tui/tui-completion.exp

[Pedro Alves]

On 11/15/2017 04:08 PM, Simon Marchi wrote:

> Hi Pedro,
> 
> I am seeing a failure in this test (gdb.tui/completion.exp), I pushed
> this patch to fix it.
> 

Thanks.  Guess I only tested with "make check-read1", which masks
this problem, because the regex matches as soon at the 't' in
"layout" is consumed.  Kind of ironic.  :-P

Sorry about that.

Thanks,
Pedro Alves