[lldb] [llgs server] Support creating core dumps on NetBSD

Add a new SaveCore() process method that can be used to request a core
dump.  This is currently implemented on NetBSD via the PT_DUMPCORE
ptrace(2) request, and enabled via 'savecore' extension.

Protocol-wise, a new qSaveCore packet is introduced.  It accepts zero
or more semicolon-separated key:value options, invokes the core dump
and returns a key:value response.  Currently the only option supported
is "path-hint", and the return value contains the "path" actually used.
The support for the feature is exposed via qSaveCore qSupported feature.

Differential Revision: https://reviews.llvm.org/D101285

1 files changed, 52 insertions, 0 deletions

diff --git a/lldb/test/API/tools/lldb-server/TestGdbRemoteSaveCore.py b/lldb/test/API/tools/lldb-server/TestGdbRemoteSaveCore.py
new file mode 100644
index 000000000000..405a73bcdba8
--- /dev/null
+++ b/lldb/test/API/tools/lldb-server/TestGdbRemoteSaveCore.py
@@ -0,0 +1,52 @@
+import gdbremote_testcase
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+
+import binascii
+import os
+
+class TestGdbSaveCore(gdbremote_testcase.GdbRemoteTestCaseBase):
+    mydir = TestBase.compute_mydir(__file__)
+
+    def coredump_test(self, core_path=None, expect_path=None):
+        self.build()
+        self.set_inferior_startup_attach()
+        procs = self.prep_debug_monitor_and_inferior()
+        self.add_qSupported_packets()
+        ret = self.expect_gdbremote_sequence()
+        self.assertIn("qSaveCore+", ret["qSupported_response"])
+        self.reset_test_sequence()
+
+        packet = "$qSaveCore"
+        if core_path is not None:
+            packet += ";path-hint:{}".format(
+                binascii.b2a_hex(core_path.encode()).decode())
+
+        self.test_sequence.add_log_lines([
+            "read packet: {}#00".format(packet),
+            {"direction": "send", "regex": "[$]core-path:([0-9a-f]+)#.*",
+             "capture": {1: "path"}},
+        ], True)
+        ret = self.expect_gdbremote_sequence()
+        out_path = binascii.a2b_hex(ret["path"].encode()).decode()
+        if expect_path is not None:
+            self.assertEqual(out_path, expect_path)
+
+        target = self.dbg.CreateTarget(None)
+        process = target.LoadCore(out_path)
+        self.assertTrue(process, PROCESS_IS_VALID)
+        self.assertEqual(process.GetProcessID(), procs["inferior"].pid)
+
+    @skipUnlessPlatform(oslist=["netbsd"])
+    def test_netbsd_path(self):
+        core = lldbutil.append_to_process_working_directory(self, "core")
+        self.coredump_test(core, core)
+
+    @skipUnlessPlatform(oslist=["netbsd"])
+    def test_netbsd_no_path(self):
+        self.coredump_test()
+
+    @skipUnlessPlatform(oslist=["netbsd"])
+    def test_netbsd_bad_path(self):
+        self.coredump_test("/dev/null/cantwritehere")