gh-152132: Fix Py_RunMain() to return an exit code

Include/errcode.h

@@ -6,7 +6,7 @@
 // the parser only returns E_EOF when it hits EOF immediately, and it
 // never returns E_OK.
 //
-// The public PyRun_InteractiveOneObjectEx() function can return E_EOF,
+// The public PyRun_InteractiveOneObject() function can return E_EOF,
 // same as its variants:
 //
 // * PyRun_InteractiveOneObject()
@@ -38,6 +38,7 @@ extern "C" {
 #define E_BADSINGLE      27      /* Ill-formed single statement input */
 #define E_INTERACT_STOP  28      /* Interactive mode stopped tokenization */
 #define E_COLUMNOVERFLOW 29      /* Column offset overflow */
+#define E_EXITCODE       30      /* (internal) got SystemExit, use exitcode */
 
 #ifdef __cplusplus
 }

Include/internal/pycore_pylifecycle.h

@@ -109,7 +109,11 @@ extern int _Py_LegacyLocaleDetected(int warn);
 PyAPI_FUNC(char*) _Py_SetLocaleFromEnv(int category);
 
 // Export for special main.c string compiling with source tracebacks
-int _PyRun_SimpleStringFlagsWithName(const char *command, const char* name, PyCompilerFlags *flags);
+extern int _PyRun_SimpleString(
+    const char *command,
+    const char* name,
+    PyCompilerFlags *flags,
+    int *exitcode);
 
 
 /* interpreter config */

Include/internal/pycore_pythonrun.h

@@ -8,22 +8,25 @@ extern "C" {
 #  error "this header requires Py_BUILD_CORE define"
 #endif
 
-extern int _PyRun_SimpleFileObject(
+extern int _PyRun_SimpleFile(
     FILE *fp,
     PyObject *filename,
     int closeit,
-    PyCompilerFlags *flags);
+    PyCompilerFlags *flags,
+    int *exitcode);
 
-extern int _PyRun_AnyFileObject(
+extern int _PyRun_AnyFile(
     FILE *fp,
     PyObject *filename,
     int closeit,
-    PyCompilerFlags *flags);
+    PyCompilerFlags *flags,
+    int *exitcode);
 
-extern int _PyRun_InteractiveLoopObject(
+extern int _PyRun_InteractiveLoop(
     FILE *fp,
     PyObject *filename,
-    PyCompilerFlags *flags);
+    PyCompilerFlags *flags,
+    int *exitcode);
 
 extern int _PyObject_SupportedAsScript(PyObject *);
 extern const char* _Py_SourceAsString(

Lib/test/test_embed.py

@@ -68,6 +68,9 @@
 if not os.path.isfile(os.path.join(STDLIB_INSTALL, 'os.py')):
     STDLIB_INSTALL = None
 
+CODE_EXITCODE_123 = 'raise SystemExit(123)'
+
+
 def debug_build(program):
     program = os.path.basename(program)
     name = os.path.splitext(program)[0]
@@ -140,12 +143,16 @@ def run_embedded_interpreter(self, *args, env=None,
             env = env.copy()
             env['SYSTEMROOT'] = os.environ['SYSTEMROOT']
 
-        p = subprocess.Popen(cmd,
-                             stdout=subprocess.PIPE,
-                             stderr=subprocess.PIPE,
-                             universal_newlines=True,
-                             env=env,
-                             cwd=cwd)
+        kwargs = dict(
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+            universal_newlines=True,
+            env=env,
+            cwd=cwd,
+        )
+        if input is not None:
+            kwargs['stdin'] = subprocess.PIPE
+        p = subprocess.Popen(cmd, **kwargs)
         try:
             (out, err) = p.communicate(input=input, timeout=timeout)
         except:
@@ -590,6 +597,43 @@ def _nogil_filtered_err(err: str, mod_name: str) -> str:
         ]
         return "\n".join(filtered_err_lines)
 
+    def check_program_exitcode(self, *args, check_stderr=True, **kwargs):
+        out, err = self.run_embedded_interpreter(*args, **kwargs)
+        self.assertEqual(out.rstrip(), 'ok! Py_RunMain() returned 123')
+        if check_stderr:
+            self.assertEqual(err, '')
+
+    def test_init_run_main_code_exitcode(self):
+        code = CODE_EXITCODE_123
+        self.check_program_exitcode("test_init_run_main_code_exitcode", code)
+
+    def test_init_run_main_script_exitcode(self):
+        with tempfile.TemporaryDirectory() as tmpdir:
+            filename = os.path.join(tmpdir, 'script.py')
+            with open(filename, 'w') as fp:
+                fp.write(CODE_EXITCODE_123)
+
+            self.check_program_exitcode("test_init_run_main_script_exitcode",
+                                        filename)
+
+    def test_init_run_main_interactive_exitcode(self):
+        code = CODE_EXITCODE_123
+        self.check_program_exitcode("test_init_run_main_interactive_exitcode",
+                                    input=code,
+                                    check_stderr=False)
+
+    def test_init_run_main_module_exitcode(self):
+        with tempfile.TemporaryDirectory() as tmpdir:
+            modname = '_testembed_testmodule'
+            filename = os.path.join(tmpdir, modname + '.py')
+            with open(filename, 'x', encoding='utf8') as fp:
+                fp.write(CODE_EXITCODE_123)
+
+            env = dict(os.environ)
+            env['PYTHONPATH'] = tmpdir
+            self.check_program_exitcode("test_init_run_main_module_exitcode",
+                                        modname, env=env)
+
 
 def config_dev_mode(preconfig, config):
     preconfig['allocator'] = PYMEM_ALLOCATOR_DEBUG

Misc/NEWS.d/next/C_API/2026-07-07-21-25-09.gh-issue-152132.fXTUSD.rst

@@ -0,0 +1,3 @@
+Fix :c:func:`Py_RunMain` to return an exit code, rather than calling
+:c:func:`Py_Exit`, when running a script, a command, or the REPL. Patch by
+Victor Stinner.