[Lldb-commits] [lldb] [lldb] Add a compiler/interpreter of LLDB data formatter bytecode to lldb/examples (PR #113398)

[Jonas Devlieghere via lldb-commits]

================
@@ -0,0 +1,167 @@
+"""
+This is the llvm::Optional data formatter from llvm/utils/lldbDataFormatters.py
+with the implementation replaced by bytecode.
+"""
+
+from __future__ import annotations
+from formatter_bytecode import *
+import lldb
+
+
+def __lldb_init_module(debugger, internal_dict):
+    debugger.HandleCommand(
+        "type synthetic add -w llvm "
+        f"-l {__name__}.MyOptionalSynthProvider "
+        '-x "^MyOptional<.+>$"'
+    )
+    debugger.HandleCommand(
+        "type summary add -w llvm "
+        f"-e -F {__name__}.MyOptionalSummaryProvider "
+        '-x "^MyOptional<.+>$"'
+    )
+
+
+def stringify(bytecode: bytearray) -> str:
+    s = ""
+    in_hex = False
+    for b in bytecode:
+        if (b < 32 or b > 127 or chr(b) in ['"', "`", "'"]) or (
+            in_hex
+            and chr(b).lower()
+            in [
+                "a",
+                "b",
+                "c",
+                "d",
+                "e",
+                "f",
+                "0",
+                "1",
+                "2",
+                "3",
+                "4",
+                "5",
+                "6",
+                "7",
+                "8",
+                "9",
+            ]
+        ):
+            s += r"\x" + hex(b)[2:]
+            in_hex = True
+        else:
+            s += chr(b)
+            in_hex = False
+    return s
+
+
+def evaluate(assembler: str, data: list):
+    bytecode = compile(assembler)
+    trace = True
+    if trace:
+        print(
+            "Compiled to {0} bytes of bytecode:\n{1}".format(
+                len(bytecode), stringify(bytecode)
+            )
+        )
+    result = interpret(bytecode, [], data, False)  # trace)
+    if trace:
+        print("--> {0}".format(result))
+    return result
+
+
+# def GetOptionalValue(valobj):
+#    storage = valobj.GetChildMemberWithName("Storage")
+#    if not storage:
+#        storage = valobj
+#
+#    failure = 2
+#    hasVal = storage.GetChildMemberWithName("hasVal").GetValueAsUnsigned(failure)
+#    if hasVal == failure:
+#        return "<could not read MyOptional>"
+#
+#    if hasVal == 0:
+#        return None
+#
+#    underlying_type = storage.GetType().GetTemplateArgumentType(0)
+#    storage = storage.GetChildMemberWithName("value")
+#    return storage.Cast(underlying_type)
----------------
JDevlieghere wrote:

I was suggesting to remove it since you have the individual bits, but maybe it's good to have the whole thing there too, to get a sense of how the full formatter works. 

https://github.com/llvm/llvm-project/pull/113398