Fix: Dynamo log always emits ANSI color codes into torch_compile_debug/torchdynamo/debug.log due to colored=True in lazy_format_graph_code (#167823)

Summary:
Added ANSI escape sequence handling and a custom logging formatter.

Please refer to pytorch/pytorch#167812 for detailed background explanation.

This PR adds a format for log_file_handler in dynamo logger to filter ANSI codes.

Before this change, log in debug.log:

```
  def forward(self, L_x_: "�[31mi64�[0m�[34m[]�[0m�[2m�[34m[]�[0m�[2m�[32mcpu�[0m"):
      l_x_ = L_x_

      �[2m# File: /Users/bytedance/Downloads/Repo/pytorch/mydebug1.py:11 in forward, code: a = torch.ones(2, x.item())�[0m
      item: "Sym(s20 + 5)" = l_x_.item();  �[2ml_x_ = None�[0m
      a: "�[31mf32�[0m�[34m[2, s20 + 5]�[0m�[2m�[34m[Max(1, s20 + 5), 1]�[0m�[2m�[32mcpu�[0m" = torch.ones(�[34m2�[0m, item)

      �[2m# File: /Users/bytedance/Downloads/Repo/pytorch/mydebug1.py:12 in forward, code: b = torch.ones(3, y.item() + 5)�[0m
      b: "�[31mf32�[0m�[34m[3, s20 + 5]�[0m�[2m�[34m[Max(1, s20 + 5), 1]�[0m�[2m�[32mcpu�[0m" = torch.ones(�[34m3�[0m, item);  �[2mitem = None�[0m

      �[2m# File: /Users/bytedance/Downloads/Repo/pytorch/mydebug1.py:13 in forward, code: res = torch.cat([a, b], dim=0)�[0m
      res: "�[31mf32�[0m�[34m[5, s20 + 5]�[0m�[2m�[34m[Max(1, s20 + 5), 1]�[0m�[2m�[32mcpu�[0m" = torch.cat([a, b], dim = �[34m0�[0m);  �[2ma = b = None�[0m

      �[2m# File: /Users/bytedance/Downloads/Repo/pytorch/mydebug1.py:14 in forward, code: return res.sum()�[0m
      sum_1: "�[31mf32�[0m�[34m[]�[0m�[2m�[34m[]�[0m�[2m�[32mcpu�[0m" = res.sum();  �[2mres = None�[0m
      return (sum_1,)
```

After this change, log in debug.log:
```
  def forward(self, L_x_: "i64[][]cpu"):
      l_x_ = L_x_

      # File: /Users/bytedance/Downloads/Repo/pytorch/mydebug1.py:11 in forward, code: a = torch.ones(2, x.item())
      item: "Sym(s20 + 5)" = l_x_.item();  l_x_ = None
      a: "f32[2, s20 + 5][Max(1, s20 + 5), 1]cpu" = torch.ones(2, item)

      # File: /Users/bytedance/Downloads/Repo/pytorch/mydebug1.py:12 in forward, code: b = torch.ones(3, y.item() + 5)
      b: "f32[3, s20 + 5][Max(1, s20 + 5), 1]cpu" = torch.ones(3, item);  item = None

      # File: /Users/bytedance/Downloads/Repo/pytorch/mydebug1.py:13 in forward, code: res = torch.cat([a, b], dim=0)
      res: "f32[5, s20 + 5][Max(1, s20 + 5), 1]cpu" = torch.cat([a, b], dim = 0);  a = b = None

      # File: /Users/bytedance/Downloads/Repo/pytorch/mydebug1.py:14 in forward, code: return res.sum()
      sum_1: "f32[][]cpu" = res.sum();  res = None
      return (sum_1,)
```

X-link: pytorch/pytorch#167823
Approved by: https://github.com/angelayi

Reviewed By: yangw-dev

Differential Revision: D87297668

fbshipit-source-id: 1d2b6d08cc2a068954107515b564bf7f1c9f6e42

Author: generatedunixname499836121

userbenchmark/dynamo/dynamobench/_dynamo/utils.py

@@ -903,11 +903,33 @@ def reset_graph_break_dup_checker() -> None:
     graph_break_dup_warning_checker.reset()
 
 
+# Matches ANSI escape sequences (CSI)
+ANSI_ESCAPE_PATTERN = re.compile(
+    r"""
+    \x1B            # ESC
+    \[              # [
+    [0-?]*          # Parameter bytes
+    [ -/]*          # Intermediate bytes
+    [@-~]           # Final byte
+    """,
+    re.VERBOSE,
+)
+
+
+class StripAnsiFormatter(logging.Formatter):
+    """Logging formatter that strips ANSI escape codes."""
+
+    def format(self, record):
+        msg = super().format(record)
+        return ANSI_ESCAPE_PATTERN.sub("", msg)
+
+
 def add_file_handler() -> contextlib.ExitStack:
     log_path = os.path.join(get_debug_dir(), "torchdynamo")
     os.makedirs(log_path, exist_ok=True)
 
     log_file_handler = logging.FileHandler(os.path.join(log_path, "debug.log"))
+    log_file_handler.setFormatter(StripAnsiFormatter("%(message)s"))
     logger = logging.getLogger("torch._dynamo")
     logger.addHandler(log_file_handler)