gh-102114: Make dis print more concise tracebacks for syntax errors in str inputs (#102115)

Author: chgnrdv

Lib/dis.py

@@ -64,10 +64,10 @@ def _try_compile(source, name):
        expect code objects
     """
     try:
-        c = compile(source, name, 'eval')
+        return compile(source, name, 'eval')
     except SyntaxError:
-        c = compile(source, name, 'exec')
-    return c
+        pass
+    return compile(source, name, 'exec')
 
 def dis(x=None, *, file=None, depth=None, show_caches=False, adaptive=False):
     """Disassemble classes, methods, functions, and other compiled objects.

Lib/test/test_dis.py

@@ -1067,6 +1067,13 @@ def check(expected, **kwargs):
         check(dis_nested_2, depth=None)
         check(dis_nested_2)
 
+    def test__try_compile_no_context_exc_on_error(self):
+        # see gh-102114
+        try:
+            dis._try_compile(")", "")
+        except Exception as e:
+            self.assertIsNone(e.__context__)
+
     @staticmethod
     def code_quicken(f, times=ADAPTIVE_WARMUP_DELAY):
         for _ in range(times):

Misc/NEWS.d/next/Library/2023-02-21-14-57-34.gh-issue-102114.uUDQzb.rst

@@ -0,0 +1 @@
+Functions in the :mod:`dis` module that accept a source code string as argument now print a more concise traceback when the string contains a syntax or indentation error.