fix: rm functions_for_code usage in code origins [backport 2.21] (#13568)

Backport a6520bc from #13539 to 2.21.

Remove the call to `functions_for_code` from code origins. For
Python3.11+ we'll use the fully qualified name stored on the Code
Object:


https://docs.python.org/3/reference/datamodel.html#codeobject.co_qualname

For older version, we'll fall back to the function name.

refs: DEBUG-3967

## Checklist
- [x] PR author has checked that all the criteria below are met
- The PR description includes an overview of the change
- The PR description articulates the motivation for the change
- The change includes tests OR the PR description describes a testing
strategy
- The PR description notes risks associated with the change, if any
- Newly-added code is easy to change
- The change follows the [library release note
guidelines](https://ddtrace.readthedocs.io/en/stable/releasenotes.html)
- The change includes or references documentation updates if necessary
- Backport labels are set (if
[applicable](https://ddtrace.readthedocs.io/en/latest/contributing.html#backporting))

## Reviewer Checklist
- [x] Reviewer has checked that all the criteria below are met 
- Title is accurate
- All changes are related to the pull request's stated goal
- Avoids breaking
[API](https://ddtrace.readthedocs.io/en/stable/versioning.html#interfaces)
changes
- Testing strategy adequately addresses listed risks
- Newly-added code is easy to change
- Release note makes sense to a user of the library
- If necessary, author has acknowledged and discussed the performance
implications of this PR as reported in the benchmarks PR comment
- Backport labels are set in a manner that is consistent with the
[release branch maintenance
policy](https://ddtrace.readthedocs.io/en/latest/contributing.html#backporting)

Co-authored-by: Tyler Finethy <[email protected]>

Author: github-actions[bot]

ddtrace/debugging/_origin/span.py

@@ -28,7 +28,6 @@
 from ddtrace.internal import core
 from ddtrace.internal.packages import is_user_code
 from ddtrace.internal.safety import _isinstance
-from ddtrace.internal.utils.inspection import functions_for_code
 from ddtrace.internal.wrapping.context import WrappingContext
 from ddtrace.settings.code_origin import config as co_config
 from ddtrace.trace import Span
@@ -217,12 +216,17 @@ def on_span_start(self, span: Span) -> None:
 
                 span.set_tag_str(f"_dd.code_origin.frames.{n}.file", filename)
                 span.set_tag_str(f"_dd.code_origin.frames.{n}.line", str(code.co_firstlineno))
+
+                # Get the module and function name from the frame and code object. In Python3.11+ qualname
+                # is available, otherwise we'll fallback to the unqualified name.
                 try:
-                    (f,) = functions_for_code(code)
-                    span.set_tag_str(f"_dd.code_origin.frames.{n}.type", f.__module__)
-                    span.set_tag_str(f"_dd.code_origin.frames.{n}.method", f.__qualname__)
-                except ValueError:
-                    continue
+                    name = code.co_qualname  # type: ignore[attr-defined]
+                except AttributeError:
+                    name = code.co_name
+
+                mod = frame.f_globals.get("__name__")
+                span.set_tag_str(f"_dd.code_origin.frames.{n}.type", mod) if mod else None
+                span.set_tag_str(f"_dd.code_origin.frames.{n}.method", name) if name else None
 
                 # TODO[gab]: This will be enabled as part of the live debugger/distributed debugging
                 # if ld_config.enabled:

releasenotes/notes/fix-co-performance-4199f97341fa4aa7.yaml

@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    dynamic instrumentation: Fixed an issue with a GC-based lookup for code origin resolution resulting in high
+    performance overhead.