diff --git a/Include/internal/pycore_compile.h b/Include/internal/pycore_compile.h index c18e04bf67a5df..1c60834fa2058c 100644 --- a/Include/internal/pycore_compile.h +++ b/Include/internal/pycore_compile.h @@ -49,7 +49,8 @@ extern int _PyAST_Preprocess( PyObject *filename, int optimize, int ff_features, - int syntax_check_only); + int syntax_check_only, + int enable_warnings); typedef struct { diff --git a/Lib/test/test_ast/test_ast.py b/Lib/test/test_ast/test_ast.py index 1e6f60074308e2..500831ec5c80c3 100644 --- a/Lib/test/test_ast/test_ast.py +++ b/Lib/test/test_ast/test_ast.py @@ -1057,61 +1057,6 @@ def test_repr_large_input_crash(self): r"Exceeds the limit \(\d+ digits\)"): repr(ast.Constant(value=eval(source))) - def test_pep_765_warnings(self): - srcs = [ - textwrap.dedent(""" - def f(): - try: - pass - finally: - return 42 - """), - textwrap.dedent(""" - for x in y: - try: - pass - finally: - break - """), - textwrap.dedent(""" - for x in y: - try: - pass - finally: - continue - """), - ] - for src in srcs: - with self.assertWarnsRegex(SyntaxWarning, 'finally'): - ast.parse(src) - - def test_pep_765_no_warnings(self): - srcs = [ - textwrap.dedent(""" - try: - pass - finally: - def f(): - return 42 - """), - textwrap.dedent(""" - try: - pass - finally: - for x in y: - break - """), - textwrap.dedent(""" - try: - pass - finally: - for x in y: - continue - """), - ] - for src in srcs: - ast.parse(src) - def test_tstring(self): # Test AST structure for simple t-string tree = ast.parse('t"Hello"') diff --git a/Lib/test/test_compile.py b/Lib/test/test_compile.py index bc8ef93cb8f9de..846d38ae561fc5 100644 --- a/Lib/test/test_compile.py +++ b/Lib/test/test_compile.py @@ -1745,6 +1745,66 @@ def test_compile_warning_in_finally(self): self.assertEqual(wm.category, SyntaxWarning) self.assertIn("\"is\" with 'int' literal", str(wm.message)) + @support.subTests('src', [ + textwrap.dedent(""" + def f(): + try: + pass + finally: + return 42 + """), + textwrap.dedent(""" + for x in y: + try: + pass + finally: + break + """), + textwrap.dedent(""" + for x in y: + try: + pass + finally: + continue + """), + ]) + def test_pep_765_warnings(self, src): + with self.assertWarnsRegex(SyntaxWarning, 'finally'): + compile(src, '', 'exec') + with warnings.catch_warnings(): + warnings.simplefilter("error") + tree = ast.parse(src) + with self.assertWarnsRegex(SyntaxWarning, 'finally'): + compile(tree, '', 'exec') + + @support.subTests('src', [ + textwrap.dedent(""" + try: + pass + finally: + def f(): + return 42 + """), + textwrap.dedent(""" + try: + pass + finally: + for x in y: + break + """), + textwrap.dedent(""" + try: + pass + finally: + for x in y: + continue + """), + ]) + def test_pep_765_no_warnings(self, src): + with warnings.catch_warnings(): + warnings.simplefilter("error") + compile(src, '', 'exec') + class TestBooleanExpression(unittest.TestCase): class Value: diff --git a/Lib/test/test_pyrepl/test_interact.py b/Lib/test/test_pyrepl/test_interact.py index 1a3146da8eadc8..fd4530ebc004aa 100644 --- a/Lib/test/test_pyrepl/test_interact.py +++ b/Lib/test/test_pyrepl/test_interact.py @@ -1,5 +1,6 @@ import contextlib import io +import warnings import unittest from unittest.mock import patch from textwrap import dedent @@ -273,3 +274,28 @@ def test_incomplete_statement(self): code = "if foo:" console = InteractiveColoredConsole(namespace, filename="") self.assertTrue(_more_lines(console, code)) + + +class TestWarnings(unittest.TestCase): + def test_pep_765_warning(self): + """ + Test that a SyntaxWarning emitted from the + AST optimizer is only shown once in the REPL. + """ + # gh-131927 + console = InteractiveColoredConsole() + code = dedent("""\ + def f(): + try: + return 1 + finally: + return 2 + """) + + with warnings.catch_warnings(record=True) as caught: + warnings.simplefilter("always") + console.runsource(code) + + count = sum("'return' in a 'finally' block" in str(w.message) + for w in caught) + self.assertEqual(count, 1) diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-10-06-10-03-37.gh-issue-139640.gY5oTb2.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-10-06-10-03-37.gh-issue-139640.gY5oTb2.rst new file mode 100644 index 00000000000000..b147b430ccccf5 --- /dev/null +++ b/Misc/NEWS.d/next/Core_and_Builtins/2025-10-06-10-03-37.gh-issue-139640.gY5oTb2.rst @@ -0,0 +1,3 @@ +:func:`ast.parse` no longer emits syntax warnings for +``return``/``break``/``continue`` in ``finally`` (see :pep:`765`) -- they are +only emitted during compilation. diff --git a/Python/ast_preprocess.c b/Python/ast_preprocess.c index 44d3075098be75..fe6fd9479d1531 100644 --- a/Python/ast_preprocess.c +++ b/Python/ast_preprocess.c @@ -19,6 +19,7 @@ typedef struct { int optimize; int ff_features; int syntax_check_only; + int enable_warnings; _Py_c_array_t cf_finally; /* context for PEP 765 check */ int cf_finally_used; @@ -78,7 +79,7 @@ control_flow_in_finally_warning(const char *kw, stmt_ty n, _PyASTPreprocessState static int before_return(_PyASTPreprocessState *state, stmt_ty node_) { - if (state->cf_finally_used > 0) { + if (state->enable_warnings && state->cf_finally_used > 0) { ControlFlowInFinallyContext *ctx = get_cf_finally_top(state); if (ctx->in_finally && ! ctx->in_funcdef) { if (!control_flow_in_finally_warning("return", node_, state)) { @@ -92,7 +93,7 @@ before_return(_PyASTPreprocessState *state, stmt_ty node_) static int before_loop_exit(_PyASTPreprocessState *state, stmt_ty node_, const char *kw) { - if (state->cf_finally_used > 0) { + if (state->enable_warnings && state->cf_finally_used > 0) { ControlFlowInFinallyContext *ctx = get_cf_finally_top(state); if (ctx->in_finally && ! ctx->in_loop) { if (!control_flow_in_finally_warning(kw, node_, state)) { @@ -968,7 +969,7 @@ astfold_type_param(type_param_ty node_, PyArena *ctx_, _PyASTPreprocessState *st int _PyAST_Preprocess(mod_ty mod, PyArena *arena, PyObject *filename, int optimize, - int ff_features, int syntax_check_only) + int ff_features, int syntax_check_only, int enable_warnings) { _PyASTPreprocessState state; memset(&state, 0, sizeof(_PyASTPreprocessState)); @@ -976,6 +977,7 @@ _PyAST_Preprocess(mod_ty mod, PyArena *arena, PyObject *filename, int optimize, state.optimize = optimize; state.ff_features = ff_features; state.syntax_check_only = syntax_check_only; + state.enable_warnings = enable_warnings; if (_Py_CArray_Init(&state.cf_finally, sizeof(ControlFlowInFinallyContext), 20) < 0) { return -1; } diff --git a/Python/compile.c b/Python/compile.c index 8070d3f03760ef..e2f1c7e8eb5bce 100644 --- a/Python/compile.c +++ b/Python/compile.c @@ -136,7 +136,7 @@ compiler_setup(compiler *c, mod_ty mod, PyObject *filename, c->c_optimize = (optimize == -1) ? _Py_GetConfig()->optimization_level : optimize; c->c_save_nested_seqs = false; - if (!_PyAST_Preprocess(mod, arena, filename, c->c_optimize, merged, 0)) { + if (!_PyAST_Preprocess(mod, arena, filename, c->c_optimize, merged, 0, 1)) { return ERROR; } c->c_st = _PySymtable_Build(mod, filename, &c->c_future); @@ -1502,7 +1502,7 @@ _PyCompile_AstPreprocess(mod_ty mod, PyObject *filename, PyCompilerFlags *cf, if (optimize == -1) { optimize = _Py_GetConfig()->optimization_level; } - if (!_PyAST_Preprocess(mod, arena, filename, optimize, flags, no_const_folding)) { + if (!_PyAST_Preprocess(mod, arena, filename, optimize, flags, no_const_folding, 0)) { return -1; } return 0;