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

Fix Py_RunMain() to return an exit code, rather than calling
Py_Exit(), when running a script, a command, or the REPL.

Changes:

* Add E_EXITCODE return value to <errcode.h> header.
* Add exitcode parameter to internal functions: _PyRun_SimpleFile(),
  _PyRun_AnyFile() and _PyRun_InteractiveLoop().
* Add unit tests.
* pymain_repl() now displays the error if PySys_Audit() or import
  _pyrepl failed.

Author: vstinner

Include/errcode.h

@@ -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 +597,40 @@ def _nogil_filtered_err(err: str, mod_name: str) -> str:
         ]
         return "\n".join(filtered_err_lines)
 
+    def test_init_run_main_code_exitcode(self):
+        env = dict(os.environ)
+        env['TEST_CODE'] = CODE_EXITCODE_123
+        self.run_embedded_interpreter("test_init_run_main_code_exitcode",
+                                      env=env)
+
+    def test_init_run_main_script_exitcode(self):
+        filename = os.path.abspath(os_helper.TESTFN + '.py')
+        with open(filename, 'x', encoding='utf8') as fp:
+            fp.write(CODE_EXITCODE_123)
+        self.addCleanup(os_helper.unlink, filename)
+
+        env = dict(os.environ)
+        env['TEST_SCRIPT'] = filename
+        self.run_embedded_interpreter("test_init_run_main_script_exitcode",
+                                      env=env)
+
+    def test_init_run_main_interactive_exitcode(self):
+        code = CODE_EXITCODE_123
+        self.run_embedded_interpreter("test_init_run_main_interactive_exitcode",
+                                      input=code)
+
+    def test_init_run_main_module_exitcode(self):
+        modname = '_testembed_testmodule'
+        filename = os.path.abspath(modname + '.py')
+        with open(filename, 'x', encoding='utf8') as fp:
+            fp.write(CODE_EXITCODE_123)
+        self.addCleanup(os_helper.unlink, filename)
+
+        env = dict(os.environ)
+        env['TEST_MODULE'] = modname
+        self.run_embedded_interpreter("test_init_run_main_module_exitcode",
+                                      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.