Introduce gdb_interact in testsuite

gdb_interact is a small utility that we have found quite useful to debug
test cases.

Putting gdb_interact in a test suspends it and allows to interact with
gdb to inspect whatever you want. You can then type ">>>" to resume the
test execution. Of course, this is only for gdb devs. It wouldn't make
sense to leave a gdb_interact permanently in a test case.

When starting the interaction with the user, the script prints this
banner:

+------------------------------------------+
| Script interrupted, you can now interact |
| with by gdb. Type >>> to continue.       |
+------------------------------------------+

Notes:
* When gdb is launched, the gdb_spawn_id variable (lib/gdb.exp) is
  assigned -1. Given the name, I would expect it to contain the gdb
  expect spawn id, which is needed for interact. I changed all places
  that set gdb_spawn_id to -1 to set it to the actual gdb spawn id
  instead.

* When entering the "interact" mode, the last (gdb) prompt is already
  eaten by expect, so it doesn't show up on the terminal. Subsequent
  prompts do appear though. We tried to print "(gdb)" just before the
  interact to replace it. However, it could be misleading if you are
  debugging an MI test case, it makes you think that you are typing in a
  CLI prompt, when in reality it's MI. In the end I decided that since
  the feature is for developers who know what they're doing and that one
  is normally consciously using gdb_interact, the script doesn't need
  to babysit the user.

* There are probably some quirks depending on where in the script
  gdb_interact appears (e.g. it could interfere with following
  commands and make them fail), but it works for most cases. Quirks can
  always be fixed later.

The idea and original implementation was contributed by Anders
Granlund, a colleague of mine. Thanks to him.

gdb/testsuite/ChangeLog:

	* gdb.base/statistics.exp: Assign spawn id to gdb_spawn_id.
	* gdb.base/valgrind-db-attach.exp: Same.
	* gdb.base/valgrind-infcall.exp: Same.
	* lib/mi-support.exp (default_mi_gdb_start): Same.
	* lib/prompt.exp (default_prompt_gdb_start): Same.
	* lib/gdb.exp (default_gdb_spawn): Same.
	(gdb_interact): New.

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index b01a4c9eb32fef7bbaacf6154fd32ba3a9fdcef0..faf84932089a0ec548eea6c8dd5adb9716d7fadb 100644 (file)
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,15 @@
+2015-01-22  Anders Granlund  <anders.granlund@ericsson.com>
+           Simon Marchi  <simon.marchi@ericsson.com>
+
+       * gdb.base/statistics.exp: Assign spawn id to gdb_spawn_id.
+       * gdb.base/valgrind-db-attach.exp: Same.
+       * gdb.base/valgrind-infcall.exp: Same.
+       * lib/mi-support.exp (default_mi_gdb_start): Same.
+       * lib/prompt.exp (default_prompt_gdb_start): Same.
+       * lib/gdb.exp (default_gdb_spawn): Same.
+       (gdb_interact): New.
+
+
 2015-01-22  Jan Kratochvil  <jan.kratochvil@redhat.com>
 
        * gdb.compile/compile.exp (pointer to jit function): New test.

diff --git a/gdb/testsuite/gdb.base/statistics.exp b/gdb/testsuite/gdb.base/statistics.exp
index bbb0a694142761bf588a27003962dc358e92cd61..dcdf5c5c98f8651ba79a54ae2393d02c403bf069 100644 (file)
--- a/gdb/testsuite/gdb.base/statistics.exp
+++ b/gdb/testsuite/gdb.base/statistics.exp
@@ -24,6 +24,6 @@ if { $res < 0 || $res == "" } {
     perror "Spawning $GDB failed."
     return
 }
-set gdb_spawn_id -1
+set gdb_spawn_id $res
 gdb_test "" "Startup time: \[0-9.\]+ \\(cpu\\), \[0-9.\]+ \\(wall\\)\r\nSpace used: \[0-9.\]+ \\(\\+\[0-9.\]+ during startup\\)" "startup time and space"
 gdb_exit

diff --git a/gdb/testsuite/gdb.base/valgrind-db-attach.exp b/gdb/testsuite/gdb.base/valgrind-db-attach.exp
index 3055d19c9fa648311f23005138049657e750d54e..89db22c8eb962b4a0ff4988570d7a46fd1c865a3 100644 (file)
--- a/gdb/testsuite/gdb.base/valgrind-db-attach.exp
+++ b/gdb/testsuite/gdb.base/valgrind-db-attach.exp
@@ -41,7 +41,7 @@ if { $res < 0 || $res == "" } {
 }
 pass $test
 # Declare GDB now as running.
-set gdb_spawn_id -1
+set gdb_spawn_id $res
 
 # GDB spawned by `valgrind --db-attach=yes' stops already after the startup is
 # executed, like with non-extended gdbserver.  It is also not correct to

diff --git a/gdb/testsuite/gdb.base/valgrind-infcall.exp b/gdb/testsuite/gdb.base/valgrind-infcall.exp
index ad81e91ce9dee95489f1811fb3fa722dfaf53110..3d3fdd3c587c7713205b576eafd4b681677285c2 100644 (file)
--- a/gdb/testsuite/gdb.base/valgrind-infcall.exp
+++ b/gdb/testsuite/gdb.base/valgrind-infcall.exp
@@ -33,7 +33,7 @@ if { $res < 0 || $res == "" } {
 }
 pass $test
 # Declare GDB now as running.
-set gdb_spawn_id -1
+set gdb_spawn_id $res
 
 # GDB started by vgdb stops already after the startup is executed, like with
 # non-extended gdbserver.  It is also not correct to run/attach the inferior.

diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index d3a3350a253f9a674c94f519bcda99cd9cdd2529..a6f200fa2158577035013700be11a1b3b8742555 100644 (file)
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -1444,7 +1444,8 @@ proc default_gdb_spawn { } {
        perror "Spawning $GDB failed."
        return 1
     }
-    set gdb_spawn_id -1
+
+    set gdb_spawn_id $res
     return 0
 }
 
@@ -1516,6 +1517,24 @@ proc default_gdb_start { } {
     return 0
 }
 
+# Utility procedure to give user control of the gdb prompt in a script. It is
+# meant to be used for debugging test cases, and should not be left in the
+# test cases code.
+
+proc gdb_interact { } {
+    global gdb_spawn_id
+    set spawn_id $gdb_spawn_id
+
+    send_user "+------------------------------------------+\n"
+    send_user "| Script interrupted, you can now interact |\n"
+    send_user "| with by gdb. Type >>> to continue.       |\n"
+    send_user "+------------------------------------------+\n"
+
+    interact {
+       ">>>" return
+    }
+}
+
 # Examine the output of compilation to determine whether compilation
 # failed or not.  If it failed determine whether it is due to missing
 # compiler or due to compiler error.  Report pass, fail or unsupported

diff --git a/gdb/testsuite/lib/mi-support.exp b/gdb/testsuite/lib/mi-support.exp
index f1b9c2b6ee32bc871666ac316fdbf9ec6cb18a8c..20546f64bef844804246c24b8517fb21f5480571 100644 (file)
--- a/gdb/testsuite/lib/mi-support.exp
+++ b/gdb/testsuite/lib/mi-support.exp
@@ -191,7 +191,7 @@ proc default_mi_gdb_start { args } {
            return -1
        }
     }
-    set gdb_spawn_id -1
+    set gdb_spawn_id $res
 
     # FIXME: mi output does not go through pagers, so these can be removed.
     # force the height to "unlimited", so no pagers get used

diff --git a/gdb/testsuite/lib/prompt.exp b/gdb/testsuite/lib/prompt.exp
index 198252476ace4677ffd5e2a795456134ee46a005..a9696a44505115e2a39f67a52e32217e9bf8c0ba 100644 (file)
--- a/gdb/testsuite/lib/prompt.exp
+++ b/gdb/testsuite/lib/prompt.exp
@@ -78,7 +78,7 @@ proc default_prompt_gdb_start { } {
            return -1
        }
     }
-    set gdb_spawn_id -1
+    set gdb_spawn_id $res
     return 0
 }