Implement gdb.execute_mi

This adds a new Python function, gdb.execute_mi, that can be used to
invoke an MI command but get the output as a Python object, rather
than a string.  This is done by implementing a new ui_out subclass
that builds a Python object.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=11688
Reviewed-By: Eli Zaretskii <eliz@gnu.org>

2 files changed, 59 insertions, 0 deletions

diff --git a/gdb/testsuite/gdb.python/py-exec-mi.exp b/gdb/testsuite/gdb.python/py-exec-mi.exp
new file mode 100644
index 0000000..09c4877
--- /dev/null
+++ b/gdb/testsuite/gdb.python/py-exec-mi.exp
@@ -0,0 +1,32 @@
+# Copyright (C) 2023 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/>.
+
+# Test gdb.execute_mi.
+
+load_lib gdb-python.exp
+require allow_python_tests
+
+clean_restart
+
+gdb_test_no_output "source ${srcdir}/${subdir}/py-mi-cmd.py" \
+    "load python file"
+
+gdb_test "python run_execute_mi_tests()" "PASS"
+
+# Be sure to test a command implemented as CLI command, as those fetch
+# the args.
+gdb_test_no_output "python gdb.execute_mi('-exec-arguments', 'a', 'b', 'c')" \
+    "set arguments"
+
+gdb_test "show args" ".*\"a b c\"."
diff --git a/gdb/testsuite/gdb.python/py-mi-cmd.py b/gdb/testsuite/gdb.python/py-mi-cmd.py
index c7bf5b7..2c86c90 100644
--- a/gdb/testsuite/gdb.python/py-mi-cmd.py
+++ b/gdb/testsuite/gdb.python/py-mi-cmd.py
@@ -118,3 +118,30 @@ def free_invoke(obj, args):
 # these as a Python function which is then called from the exp script.
 def run_exception_tests():
     print("PASS")
+
+
+# Run some execute_mi tests.  This is easier to do from Python.
+def run_execute_mi_tests():
+    # Install the command.
+    cmd = pycmd1("-pycmd")
+    # Pass in a representative subset of the pycmd1 keys, and then
+    # check that the result via MI is the same as the result via a
+    # direct Python call.  Note that some results won't compare as
+    # equal -- for example, a Python MI command can return a tuple,
+    # but that will be translated to a Python list.
+    for name in ("int", "str", "dct"):
+        expect = cmd.invoke([name])
+        got = gdb.execute_mi("-pycmd", name)
+        if expect != got:
+            print("FAIL: saw " + repr(got) + ", but expected " + repr(expect))
+            return
+    ok = False
+    try:
+        gdb.execute_mi("-pycmd", "exp")
+    # Due to the "denaturation" problem, we have to expect a gdb.error
+    # here and not a gdb.GdbError.
+    except gdb.error:
+        ok = True
+    if not ok:
+        print("FAIL: did not throw exception")
+    print("PASS")