(Ada) Add gdb-mi support for stopping at start of exception handler.

Following my previous commit which add support for stopping at start of
exception handler, this commit adds required gdb-mi support for this
feature.

gdb/ChangeLog:

    * mi/mi-cmd-catch.c (mi_cmd_catch_handlers): New function.
    * mi/mi-cmds.c (mi_cmds): Add catch-handlers command.
    * mi/mi-cmds.h (mi_cmd_catch_handlers): Add external declaration.
    * NEWS: Document "-catch-handlers" command.

gdb/doc/ChangeLog:

    * gdb.texinfo (Ada Exception gdb/mi Catchpoints): Add
    documentation for new "-catch-handlers" command.

gdb/testsuite/ChangeLog:

    * gdb.ada/mi_catch_ex_hand.exp: New testcase.
    * gdb.ada/mi_catch_ex_hand/foo.adb: New file.

Tested on x86_64-linux.

2 files changed, 170 insertions, 0 deletions

diff --git a/gdb/testsuite/gdb.ada/mi_catch_ex_hand.exp b/gdb/testsuite/gdb.ada/mi_catch_ex_hand.exp
new file mode 100644
index 0000000..5ea4fa8
--- /dev/null
+++ b/gdb/testsuite/gdb.ada/mi_catch_ex_hand.exp
@@ -0,0 +1,137 @@
+# Copyright 2011-2018 Free Software Foundation, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+load_lib "ada.exp"
+
+standard_ada_testfile foo
+
+if {[gdb_compile_ada "${srcfile}" "${binfile}" executable [list debug additional_flags=-gnata ]] != "" } {
+  return -1
+}
+
+# A global variable used to simplify the maintenance of some of
+# the regular expressions below.
+set eol "\[\r\n\]+"
+
+# Before going any further, verify that we can insert exception
+# handlers catchpoints...  That way, we won't have to do this while
+# doing the actual GDB/MI testing.
+
+clean_restart ${testfile}
+
+if ![runto_main] then {
+   fail "cannot run to main, testcase aborted"
+   return 0
+}
+
+set msg "insert catchpoint on all Ada exceptions handlers"
+gdb_test_multiple "catch handlers" $msg {
+    -re "Catchpoint $decimal: all Ada exceptions handlers$eol$gdb_prompt $" {
+	pass $msg
+    }
+    -re "Your Ada runtime appears to be missing some debugging information.*\[\r\n\]+$gdb_prompt $" {
+	# If the runtime was not built with enough debug information,
+	# or if it was stripped, we can not test exception
+	# catchpoints.
+	unsupported $msg
+	return -1
+    }
+}
+
+# Now, we can start the GDB/MI testing itself...
+
+load_lib mi-support.exp
+set MIFLAGS "-i=mi"
+
+gdb_exit
+if [mi_gdb_start] {
+    continue
+}
+
+#############################################
+# 1. Try catching all exceptions handlers.  #
+#############################################
+
+if ![mi_run_to_main] then {
+   fail "cannot run to main, testcase aborted"
+   return 0
+}
+
+mi_gdb_test "-catch-handlers" \
+            "\\^done,bkptno=\"$decimal\",bkpt={.*disp=\"keep\",enabled=\"y\",addr=\"$hex\",what=\"all Ada exceptions handlers\",.*}" \
+            "catch all exceptions handlers"
+
+# Continue to exception handler.
+
+proc continue_to_exception_handler { test line } {
+
+    global decimal
+
+    mi_send_resuming_command "exec-continue" "$test"
+
+    # Now MI stream output.
+    mi_expect_stop \
+	"breakpoint-hit\",disp=\"keep\",bkptno=\"$decimal\",exception-name=\"exception\"?" \
+	"foo" "" ".*" "$line" \
+	".*" \
+        $test
+}
+
+# We don't have the exception name info when stopping at the exception handlers
+# catchpoints so we use source line to check if the inferior stops at the
+# right location.
+
+set bp_ce_location [gdb_get_line_number "BREAK1" ${testdir}/foo.adb]
+continue_to_exception_handler \
+    "continue until CE handling caught by all-exceptions handlers catchpoint" \
+    "$bp_ce_location"
+
+set bp_pe_location [gdb_get_line_number "BREAK2" ${testdir}/foo.adb]
+continue_to_exception_handler \
+    "continue until PE handling caught by all-exceptions handlers catchpoint" \
+    "$bp_pe_location"
+
+##########################################################
+# 2. Try catching only some of the exceptions handlers.  #
+##########################################################
+
+# Here is the scenario:
+#  - Restart the debugger from scratch, runto_main
+#  - We'll catch only "Constraint_Error handlers"
+#  - continue, we should stop at the Constraint_Error exception handler
+#  - continue, we should not stop at the Program_Error exception handler
+#    but exit instead.
+
+if ![mi_run_to_main] then {
+   fail "cannot run to main, testcase aborted"
+   return 0
+}
+
+mi_gdb_test "-catch-handlers -e Constraint_Error" \
+            "\\^done,bkptno=\"$decimal\",bkpt={.*disp=\"keep\",enabled=\"y\",addr=\"$hex\",what=\"`Constraint_Error' Ada exception handlers\",.*}" \
+            "catch Constraint_Error"
+
+mi_execute_to "exec-continue" \
+              "breakpoint-hit\",disp=\"keep\",bkptno=\"$decimal\",exception-name=\"exception\"?" \
+              "foo" "" ".*" "$bp_ce_location" \
+              ".*" \
+              "continue to exception catchpoint hit"
+
+# Exit the inferior.
+mi_send_resuming_command "exec-continue" "continuing to inferior exit"
+mi_expect_stop "exited-normally" "" "" "" "" "" "exit normally"
+
+mi_gdb_exit
+return 0
diff --git a/gdb/testsuite/gdb.ada/mi_catch_ex_hand/foo.adb b/gdb/testsuite/gdb.ada/mi_catch_ex_hand/foo.adb
new file mode 100644
index 0000000..da701a3
--- /dev/null
+++ b/gdb/testsuite/gdb.ada/mi_catch_ex_hand/foo.adb
@@ -0,0 +1,33 @@
+--  Copyright 2007-2018 Free Software Foundation, Inc.
+--
+--  This program is free software; you can redistribute it and/or modify
+--  it under the terms of the GNU General Public License as published by
+--  the Free Software Foundation; either version 3 of the License, or
+--  (at your option) any later version.
+--
+--  This program is distributed in the hope that it will be useful,
+--  but WITHOUT ANY WARRANTY; without even the implied warranty of
+--  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+--  GNU General Public License for more details.
+--
+--  You should have received a copy of the GNU General Public License
+--  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+procedure Foo is
+begin
+
+   begin
+      raise Constraint_Error;
+   exception
+      when Constraint_Error => -- BREAK1
+         null;
+   end;
+
+   begin
+      raise Program_Error;
+   exception
+      when Program_Error => -- BREAK2
+         null;
+   end;
+
+end Foo;