SERVER-41167 Write mongo type pretty printers for LLDB

2 files changed, 163 insertions, 0 deletions

diff --git a/.lldbinit b/.lldbinit
new file mode 100644
index 00000000000..a6c588a6cc9
--- /dev/null
+++ b/.lldbinit
@@ -0,0 +1,5 @@
+# To use our LLDB extensions add the following to the file ~/.lldbinit:
+#
+#     settings set target.load-cwd-lldbinit true
+#
+command script import buildscripts/lldb/lldb_printers.py
\ No newline at end of file
diff --git a/buildscripts/lldb/lldb_printers.py b/buildscripts/lldb/lldb_printers.py
new file mode 100644
index 00000000000..669c65ef647
--- /dev/null
+++ b/buildscripts/lldb/lldb_printers.py
@@ -0,0 +1,158 @@
+"""LLDB Pretty-printers for MongoDB.
+
+To import script in lldb, run:
+
+   command script import buildscripts/lldb/lldb_printers.py
+
+This file must maintain Python 2 and 3 compatibility until Apple
+upgrades to Python 3 and updates their LLDB to use it.
+"""
+from __future__ import print_function
+
+import string
+import struct
+import sys
+import uuid
+
+import lldb
+
+try:
+    import bson
+    import collections
+    from bson import json_util
+    from bson.codec_options import CodecOptions
+except ImportError as err:
+    print("Warning: Could not load bson library for Python {}.".format(sys.version))
+    print("Check with the pip command if pymongo 3.x is installed.")
+    bson = None
+
+
+def __lldb_init_module(debugger, dict):
+    ############################
+    # register pretty printers #
+    ############################
+    debugger.HandleCommand("type summary add -s 'A${*var.__ptr_.__value_}' -x '^std::__1::unique_ptr<.+>$'")
+    debugger.HandleCommand("type summary add mongo::BSONObj -F lldb_printers.BSONObjPrinter")
+    debugger.HandleCommand("type summary add mongo::Status -F lldb_printers.StatusPrinter")
+    debugger.HandleCommand("type summary add mongo::StatusWith -F lldb_printers.StatusWithPrinter")
+    debugger.HandleCommand("type summary add mongo::StringData -F lldb_printers.StringDataPrinter")
+    debugger.HandleCommand("type summary add mongo::UUID -F lldb_printers.UUIDPrinter")
+    debugger.HandleCommand("type summary add --summary-string '${var.m_pathname}' 'boost::filesystem::path'")
+    debugger.HandleCommand("type synthetic add -x '^boost::optional<.+>$' --python-class lldb_printers.OptionalPrinter")
+    debugger.HandleCommand("type synthetic add -x '^std::unique_ptr<.+>$' --python-class lldb_printers.UniquePtrPrinter")
+
+
+#############################
+# Pretty Printer Defintions #
+#############################
+
+def StatusPrinter(valobj, *args):
+    err = valobj.GetChildMemberWithName("_error")
+    code = err.\
+        GetChildMemberWithName("code").\
+        GetValue()
+    if code is None:
+        return "Status::OK()"
+    reason = err.\
+        GetChildMemberWithName("reason").\
+        GetSummary()
+    return "Status({}, {})".format(code, reason)
+
+
+def StatusWithPrinter(valobj, *args):
+    status = valobj.GetChildMemberWithName("_status")
+    code = status.GetChildMemberWithName("_error").\
+        GetChildMemberWithName("code").\
+        GetValue()
+    if code is None:
+        return "StatusWith(OK, {})".format(valobj.GetChildMemberWithName("_t").GetValue())
+    rep = StatusPrinter(status)
+    return rep.replace("Status", "StatusWith", 1)
+
+
+def StringDataPrinter(valobj, *args):
+    ptr = valobj.GetChildMemberWithName("_data").GetValueAsUnsigned()
+    size1 = valobj.GetChildMemberWithName("_size").GetValueAsUnsigned(0)
+    return '"{}"'.format(valobj.GetProcess().ReadMemory(ptr, size1, lldb.SBError()).encode("utf-8"))
+
+
+def BSONObjPrinter(valobj, *args):
+    ptr = valobj.GetChildMemberWithName("_objdata").GetValueAsUnsigned()
+    size = struct.unpack("<I", valobj.GetProcess().ReadMemory(ptr, 4, lldb.SBError()))[0]
+    if size < 5 or size > 17 * 1024 * 1024:
+        return
+    buf = bson.BSON(bytes(valobj.GetProcess().ReadMemory(ptr, size, lldb.SBError())))
+    buf_str = buf.decode()
+    obj = json_util.dumps(buf_str, indent=4)
+    # If the object is huge then just dump it as one line
+    if obj.count("\n") > 1000:
+        return json_util.dumps(buf_str)
+    # Otherwise try to be nice and pretty print the JSON
+    return obj
+
+
+def UUIDPrinter(valobj, *args):
+    char_array = valobj.GetChildMemberWithName("_uuid").GetChildAtIndex(0)
+    raw_bytes = [x.GetValueAsUnsigned() for x in char_array]
+    uuid_hex_bytes = [hex(b)[2:].zfill(2) for b in raw_bytes]
+    return str(uuid.UUID("".join(uuid_hex_bytes)))
+
+
+class UniquePtrPrinter:
+    def __init__(self, valobj, dict):
+        self.valobj = valobj
+        self.update()
+
+    def num_children(self):
+        return 1
+
+    def get_child_index(self, name):
+        if name == "ptr":
+            return 0
+        else:
+            return None
+
+    def get_child_at_index(self, index):
+        if index == 0:
+            return self.valobj.GetChildMemberWithName("__ptr_").GetChildMemberWithName("__value_").Dereference()
+        else:
+            return None
+
+    def has_children():
+        return True
+
+    def update(self):
+        pass
+
+
+class OptionalPrinter:
+    def __init__(self, valobj, dict):
+        self.valobj = valobj
+        self.update()
+
+    def num_children(self):
+        return 1
+
+    def get_child_index(self, name):
+        if name == "value":
+            return 0
+        else:
+            return None
+
+    def get_child_at_index(self, index):
+        if index == 0:
+            return self.value
+        else:
+            return None
+
+    def has_children():
+        return True
+
+    def update(self):
+        self.is_init = self.valobj.GetChildMemberWithName("m_initialized").GetValueAsUnsigned() != 0
+        self.value = None
+        if self.is_init:
+            temp_type = self.valobj.GetType().GetTemplateArgumentType(0)
+            storage = self.valobj.GetChildMemberWithName("m_storage")
+            self.value = storage.Cast(temp_type)
+