[lldb] Add a print_flags command (#7358)

misc/lldb_rb/commands/print_flags_command.py

@@ -0,0 +1,31 @@
+import lldb
+import re
+
+from lldb_rb.constants import *
+from lldb_rb.rb_base_command import RbBaseCommand
+
+class PrintFlagsCommand(RbBaseCommand):
+    program = "print_flags"
+
+    help_string = "Print out the individial flags of an RVALUE object in human readable format"
+
+    # call is where our command logic will be implemented
+    def call(self, debugger, command, exe_ctx, result):
+        rclass_t = self.target.FindFirstType("struct RBasic")
+        rcass_ptr = self.target.EvaluateExpression(command).Cast(rclass_t.GetPointerType())
+        obj_flags = rcass_ptr.GetValueForExpressionPath("->flags").GetValueAsUnsigned()
+
+        flags = [
+            "RUBY_FL_WB_PROTECTED", "RUBY_FL_PROMOTED0", "RUBY_FL_PROMOTED1", "RUBY_FL_FINALIZE",
+            "RUBY_FL_SHAREABLE", "RUBY_FL_EXIVAR", "RUBY_FL_FREEZE",
+            "RUBY_FL_USER0", "RUBY_FL_USER1", "RUBY_FL_USER2", "RUBY_FL_USER3", "RUBY_FL_USER4",
+            "RUBY_FL_USER5", "RUBY_FL_USER6", "RUBY_FL_USER7", "RUBY_FL_USER8", "RUBY_FL_USER9",
+            "RUBY_FL_USER10", "RUBY_FL_USER11", "RUBY_FL_USER12", "RUBY_FL_USER13", "RUBY_FL_USER14",
+            "RUBY_FL_USER15", "RUBY_FL_USER16", "RUBY_FL_USER17", "RUBY_FL_USER18"
+        ]
+
+        types_index = {v: k for k, v in self.ruby_globals.items() if re.match(r'RUBY_T_', k)}
+        print("TYPE: {}".format(types_index[obj_flags & self.ruby_globals["RUBY_T_MASK"]]))
+        for flag in flags:
+            output = "{} : {}".format(flag, "1" if (obj_flags & self.ruby_globals[flag]) else "0")
+            print(output, file=result)

misc/lldb_rb/rb_base_command.py

@@ -34,14 +34,13 @@ class RbBaseCommand:
                 if name.startswith("RUBY_T_"):
                     value_types.append(name)
         g["value_types"] = value_types
+        return g
 
     def __init__(self, debugger, _internal_dict):
+        self.ruby_globals = RbBaseCommand.lldb_init(debugger)
         self.internal_dict = _internal_dict
 
     def __call__(self, debugger, command, exe_ctx, result):
-        if not ("RUBY_Qfalse" in globals()):
-            RbBaseCommand.lldb_init(debugger)
-
         self.build_environment(debugger)
         self.call(debugger, command, exe_ctx, result)