[RFA/doco] (Ada) provide the exception message when hitting an exception catchpoint
Joel Brobecker
brobecker@adacore.com
Fri Nov 17 21:20:00 GMT 2017
Hello,
This patch enhances the debugger to print the exception message, when
available, as part of an exception catchpoint hit notification (both
GDB/CLI and GDB/MI). For instance, with the following code...
procedure A is
begin
raise Constraint_Error with "hello world";
end A;
... instead of printing...
Catchpoint 1, CONSTRAINT_ERROR at 0x000000000040245c in a () at a.adb:3
... it now prints:
Catchpoint 1, CONSTRAINT_ERROR (hello world) at 0x000000000040245c in a ()
^^^^^^^^^^^^^
This enhancement requires runtime support. If not present, the debugger
just behaves as before.
In GDB/MI mode, if the exception message is available, it is provided
as an extra field named "exception-message" in the catchpoint notification:
*stopped,bkptno="1",[...],exception-name="CONSTRAINT_ERROR",
exception-message="hello world",[...]
gdb/ChangeLog:
* ada-lang.c (ada_exception_message_1, ada_exception_message):
New functions.
(print_it_exception): If available, display the exception
message as well.
NEWS: Document new feature.
gdb/doc/ChangeLog:
* gdb.texinfo (GDB/MI Ada Exception Information): Document
new "exception-message" field.
gdb/testsuite/ChangeLog:
* gdb.ada/catch_ex.exp, gdb.ada/mi_catch_ex.exp,
gdb.ada/mi_ex_cond.exp: Accept optional exception message in
when hitting an exception catchpoint.
Tested on x86_64-linux, no regression.
Are the NEWS and doc/gdb.texinfo changes OK to commit?
Thank you,
--
Joel
---
gdb/NEWS | 5 +++
gdb/ada-lang.c | 81 +++++++++++++++++++++++++++++++++++
gdb/doc/gdb.texinfo | 4 +-
gdb/testsuite/gdb.ada/catch_ex.exp | 8 ++--
gdb/testsuite/gdb.ada/mi_catch_ex.exp | 10 ++---
gdb/testsuite/gdb.ada/mi_ex_cond.exp | 2 +-
6 files changed, 99 insertions(+), 11 deletions(-)
diff --git a/gdb/NEWS b/gdb/NEWS
index dc070fa..5928bd6 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -52,6 +52,11 @@
variables that are to be set or unset from GDB. These variables
will affect the environment to be passed to the inferior.
+* When catching an Ada exception raised with a message, GDB now prints
+ the message in the catchpoint hit notification. In GDB/MI mode, that
+ information is provided as an extra field named "exception-message"
+ in the *stopped notification.
+
* New remote packets
QEnvironmentHexEncoded
diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c
index 33c4e8e..3265c21 100644
--- a/gdb/ada-lang.c
+++ b/gdb/ada-lang.c
@@ -12105,6 +12105,73 @@ ada_exception_name_addr_1 (enum ada_exception_catchpoint_kind ex,
return 0; /* Should never be reached. */
}
+/* Assuming the inferior is stopped at an exception catchpoint,
+ return the message which was associated to the exception, if
+ available. Return NULL if the message could not be retrieved.
+
+ The caller must xfree the string after use.
+
+ Note: The exception message can be associated to an exception
+ either through the use of the Raise_Exception function, or
+ more simply (Ada 2005 and later), via:
+
+ raise Exception_Name with "exception message";
+
+ */
+
+static char *
+ada_exception_message_1 (void)
+{
+ struct value *e_msg_val;
+ char *e_msg = NULL;
+ int e_msg_len;
+ struct cleanup *cleanups;
+
+ /* For runtimes that support this feature, the exception message
+ is passed as an unbounded string argument called "message". */
+ e_msg_val = parse_and_eval ("message");
+ if (e_msg_val == NULL)
+ return NULL; /* Exception message not supported. */
+
+ e_msg_val = ada_coerce_to_simple_array (e_msg_val);
+ gdb_assert (e_msg_val != NULL);
+ e_msg_len = TYPE_LENGTH (value_type (e_msg_val));
+
+ /* If the message string is empty, then treat it as if there was
+ no exception message. */
+ if (e_msg_len <= 0)
+ return NULL;
+
+ e_msg = (char *) xmalloc (e_msg_len + 1);
+ cleanups = make_cleanup (xfree, e_msg);
+ read_memory_string (value_address (e_msg_val), e_msg, e_msg_len + 1);
+ e_msg[e_msg_len] = '\0';
+
+ discard_cleanups (cleanups);
+ return e_msg;
+}
+
+/* Same as ada_exception_message_1, except that all exceptions are
+ contained here (returning NULL instead). */
+
+static char *
+ada_exception_message (void)
+{
+ char *e_msg = NULL; /* Avoid a spurious uninitialized warning. */
+
+ TRY
+ {
+ e_msg = ada_exception_message_1 ();
+ }
+ CATCH (e, RETURN_MASK_ERROR)
+ {
+ e_msg = NULL;
+ }
+ END_CATCH
+
+ return e_msg;
+}
+
/* Same as ada_exception_name_addr_1, except that it intercepts and contains
any error that ada_exception_name_addr_1 might cause to be thrown.
When an error is intercepted, a warning with the error message is printed,
@@ -12340,6 +12407,7 @@ print_it_exception (enum ada_exception_catchpoint_kind ex, bpstat bs)
{
struct ui_out *uiout = current_uiout;
struct breakpoint *b = bs->breakpoint_at;
+ char *exception_message;
annotate_catchpoint (b->number);
@@ -12405,6 +12473,19 @@ print_it_exception (enum ada_exception_catchpoint_kind ex, bpstat bs)
uiout->text ("failed assertion");
break;
}
+
+ exception_message = ada_exception_message ();
+ if (exception_message != NULL)
+ {
+ struct cleanup *cleanups = make_cleanup (xfree, exception_message);
+
+ uiout->text (" (");
+ uiout->field_string ("exception-message", exception_message);
+ uiout->text (")");
+
+ do_cleanups (cleanups);
+ }
+
uiout->text (" at ");
ada_find_printable_frame (get_current_frame ());
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 29d4789..430db0f 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -27183,7 +27183,9 @@ thread was last seen on. This field is optional.
Whenever a @code{*stopped} record is emitted because the program
stopped after hitting an exception catchpoint (@pxref{Set Catchpoints}),
@value{GDBN} provides the name of the exception that was raised via
-the @code{exception-name} field.
+the @code{exception-name} field. Also, for exceptions that were raised
+with an exception message, @value{GDBN} provides that message via
+the @code{exception-message} field.
@c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@node GDB/MI Simple Examples
diff --git a/gdb/testsuite/gdb.ada/catch_ex.exp b/gdb/testsuite/gdb.ada/catch_ex.exp
index 5313e77..3797601 100644
--- a/gdb/testsuite/gdb.ada/catch_ex.exp
+++ b/gdb/testsuite/gdb.ada/catch_ex.exp
@@ -62,13 +62,13 @@ gdb_test "info break" \
"info break, catch all Ada exceptions"
set catchpoint_msg \
- "Catchpoint $any_nb, CONSTRAINT_ERROR at $any_addr in foo \\\(\\\).*at .*foo.adb:$any_nb"
+ "Catchpoint $any_nb, CONSTRAINT_ERROR (\\\(foo\\.adb:$decimal explicit raise\\\) )?at $any_addr in foo \\\(\\\).*at .*foo.adb:$any_nb"
gdb_test "continue" \
"Continuing\.$eol$catchpoint_msg$eol.*SPOT1" \
"continuing to first exception"
set catchpoint_msg \
- "Catchpoint $any_nb, PROGRAM_ERROR at $any_addr in foo \\\(\\\).*at .*foo.adb:$any_nb"
+ "Catchpoint $any_nb, PROGRAM_ERROR (\\\(foo\\.adb:$decimal explicit raise\\\) )?at $any_addr in foo \\\(\\\).*at .*foo.adb:$any_nb"
gdb_test "continue" \
"Continuing\.$eol$catchpoint_msg$eol.*SPOT2" \
"continuing to second exception"
@@ -116,7 +116,7 @@ gdb_test "info break" \
"info break, second run"
set catchpoint_msg \
- "Catchpoint $any_nb, PROGRAM_ERROR at $any_addr in foo \\\(\\\).*at .*foo.adb:$any_nb"
+ "Catchpoint $any_nb, PROGRAM_ERROR (\\\(foo.adb:$decimal explicit raise\\\) )?at $any_addr in foo \\\(\\\).*at .*foo.adb:$any_nb"
gdb_test "continue" \
"Continuing\.$eol$catchpoint_msg$eol.*SPOT2" \
"continuing to Program_Error exception"
@@ -157,7 +157,7 @@ gdb_test "tcatch exception" \
"Temporary catchpoint $any_nb: all Ada exceptions"
set temp_catchpoint_msg \
- "Temporary catchpoint $any_nb, CONSTRAINT_ERROR at $any_addr in foo \\\(\\\).*at .*foo.adb:$any_nb"
+ "Temporary catchpoint $any_nb, CONSTRAINT_ERROR (\\\(.*\\\) )?at $any_addr in foo \\\(\\\).*at .*foo.adb:$any_nb"
gdb_test "continue" \
"Continuing\.$eol$temp_catchpoint_msg$eol.*SPOT1" \
"continuing to temporary catchpoint"
diff --git a/gdb/testsuite/gdb.ada/mi_catch_ex.exp b/gdb/testsuite/gdb.ada/mi_catch_ex.exp
index c9dd616..2ca3b6c 100644
--- a/gdb/testsuite/gdb.ada/mi_catch_ex.exp
+++ b/gdb/testsuite/gdb.ada/mi_catch_ex.exp
@@ -80,7 +80,7 @@ mi_gdb_test "-catch-exception" \
# Continue to caught exception.
-proc continue_to_exception { exception_name test } {
+proc continue_to_exception { exception_name exception_message test } {
global hex any_nb
mi_send_resuming_command "exec-continue" "$test"
@@ -97,18 +97,18 @@ proc continue_to_exception { exception_name test } {
# Now MI stream output.
mi_expect_stop \
- "breakpoint-hit\",disp=\"keep\",bkptno=\"$any_nb\",exception-name=\"$exception_name" \
+ "breakpoint-hit\",disp=\"keep\",bkptno=\"$any_nb\",exception-name=\"$exception_name(\",exception-message=\"$exception_message)?" \
"foo" "" ".*" ".*" \
".*" \
$test
}
continue_to_exception \
- "CONSTRAINT_ERROR" \
+ "CONSTRAINT_ERROR" "foo\\.adb:$decimal explicit raise" \
"continue until CE caught by all-exceptions catchpoint"
continue_to_exception \
- "PROGRAM_ERROR" \
+ "PROGRAM_ERROR" "foo\\.adb:$decimal explicit raise" \
"continue until PE caught by all-exceptions catchpoint"
################################################
@@ -143,7 +143,7 @@ mi_gdb_test "-catch-exception -u" \
"catch unhandled exceptions"
mi_execute_to "exec-continue" \
- "breakpoint-hit\",disp=\"keep\",bkptno=\"$any_nb\",exception-name=\"PROGRAM_ERROR" \
+ "breakpoint-hit\",disp=\"keep\",bkptno=\"$any_nb\",exception-name=\"PROGRAM_ERROR(\",exception-message=\"foo\\.adb:$decimal explicit raise)?" \
"foo" "" ".*" ".*" \
".*" \
"continue to exception catchpoint hit"
diff --git a/gdb/testsuite/gdb.ada/mi_ex_cond.exp b/gdb/testsuite/gdb.ada/mi_ex_cond.exp
index 78765be..369f155 100644
--- a/gdb/testsuite/gdb.ada/mi_ex_cond.exp
+++ b/gdb/testsuite/gdb.ada/mi_ex_cond.exp
@@ -81,7 +81,7 @@ mi_gdb_test "-catch-exception -c \"i = 2\" -e constraint_error" \
mi_run_cmd
mi_expect_stop \
- "breakpoint-hit\",disp=\"keep\",bkptno=\"$any_nb\",exception-name=\"CONSTRAINT_ERROR" \
+ "breakpoint-hit\",disp=\"keep\",bkptno=\"$any_nb\",exception-name=\"CONSTRAINT_ERROR(\",exception-message=\"foo\\.adb:$decimal explicit raise)?" \
"foo" "" ".*" ".*" \
".*" \
"run to exception catchpoint hit"
--
2.1.4
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