From bc94cf7e254e43318223553a7959115573c679a5 Mon Sep 17 00:00:00 2001 From: Irit Katriel <1055913+iritkatriel@users.noreply.github.com> Date: Fri, 26 Jul 2024 14:39:56 +0100 Subject: [PATCH] gh-122245: move checks for writes and shadowing of __debug__ to symtable (#122246) --- Doc/whatsnew/3.14.rst | 5 + Lib/test/test_syntax.py | 79 ++++++++++++++++ ...-07-24-22-39-07.gh-issue-122245.LVa9v8.rst | 4 + Python/compile.c | 76 --------------- Python/symtable.c | 92 +++++++++++++++++-- 5 files changed, 173 insertions(+), 83 deletions(-) create mode 100644 Misc/NEWS.d/next/Core and Builtins/2024-07-24-22-39-07.gh-issue-122245.LVa9v8.rst diff --git a/Doc/whatsnew/3.14.rst b/Doc/whatsnew/3.14.rst index bd8bdcb6732..d2ba7ada767 100644 --- a/Doc/whatsnew/3.14.rst +++ b/Doc/whatsnew/3.14.rst @@ -80,6 +80,11 @@ Other Language Changes command line option. For example, ``python -O -c 'assert await 1'`` now produces a :exc:`SyntaxError`. (Contributed by Jelle Zijlstra in :gh:`121637`.) +* Writes to ``__debug__`` are now detected even if the code is optimized + away by the :option:`-O` command line option. For example, + ``python -O -c 'assert (__debug__ := 1)'`` now produces a + :exc:`SyntaxError`. (Contributed by Irit Katriel in :gh:`122245`.) + * Added class methods :meth:`float.from_number` and :meth:`complex.from_number` to convert a number to :class:`float` or :class:`complex` type correspondingly. They raise an error if the argument is a string. diff --git a/Lib/test/test_syntax.py b/Lib/test/test_syntax.py index cdeb26adf34..4421d03a6d2 100644 --- a/Lib/test/test_syntax.py +++ b/Lib/test/test_syntax.py @@ -59,6 +59,18 @@ SyntaxError: cannot assign to __debug__ Traceback (most recent call last): SyntaxError: cannot assign to __debug__ +>>> def __debug__(): pass +Traceback (most recent call last): +SyntaxError: cannot assign to __debug__ + +>>> async def __debug__(): pass +Traceback (most recent call last): +SyntaxError: cannot assign to __debug__ + +>>> class __debug__: pass +Traceback (most recent call last): +SyntaxError: cannot assign to __debug__ + >>> del __debug__ Traceback (most recent call last): SyntaxError: cannot delete __debug__ @@ -786,6 +798,9 @@ SyntaxError: cannot assign to __debug__ >>> __debug__: int Traceback (most recent call last): SyntaxError: cannot assign to __debug__ +>>> x.__debug__: int +Traceback (most recent call last): +SyntaxError: cannot assign to __debug__ >>> f(a=) Traceback (most recent call last): SyntaxError: expected argument value expression @@ -1182,6 +1197,24 @@ Missing ':' before suites: Traceback (most recent call last): SyntaxError: expected ':' + >>> match x: + ... case a, __debug__, b: + ... pass + Traceback (most recent call last): + SyntaxError: cannot assign to __debug__ + + >>> match x: + ... case a, b, *__debug__: + ... pass + Traceback (most recent call last): + SyntaxError: cannot assign to __debug__ + + >>> match x: + ... case Foo(a, __debug__=1, b=2): + ... pass + Traceback (most recent call last): + SyntaxError: cannot assign to __debug__ + >>> if x = 3: ... pass Traceback (most recent call last): @@ -1275,6 +1308,15 @@ Custom error messages for try blocks that are not followed by except/finally Traceback (most recent call last): SyntaxError: expected 'except' or 'finally' block +Custom error message for __debug__ as exception variable + + >>> try: + ... pass + ... except TypeError as __debug__: + ... pass + Traceback (most recent call last): + SyntaxError: cannot assign to __debug__ + Custom error message for try block mixing except and except* >>> try: @@ -1522,6 +1564,19 @@ Specialized indentation errors: Traceback (most recent call last): IndentationError: expected an indented block after class definition on line 1 + >>> class C(__debug__=42): ... + Traceback (most recent call last): + SyntaxError: cannot assign to __debug__ + + >>> class Meta(type): + ... def __new__(*args, **kwargs): + ... pass + + >>> class C(metaclass=Meta, __debug__=42): + ... pass + Traceback (most recent call last): + SyntaxError: cannot assign to __debug__ + >>> match something: ... pass Traceback (most recent call last): @@ -1708,6 +1763,26 @@ SyntaxError: Did you mean to use 'from ... import ...' instead? Traceback (most recent call last): SyntaxError: Did you mean to use 'from ... import ...' instead? +>>> import __debug__ +Traceback (most recent call last): +SyntaxError: cannot assign to __debug__ + +>>> import a as __debug__ +Traceback (most recent call last): +SyntaxError: cannot assign to __debug__ + +>>> import a.b.c as __debug__ +Traceback (most recent call last): +SyntaxError: cannot assign to __debug__ + +>>> from a import __debug__ +Traceback (most recent call last): +SyntaxError: cannot assign to __debug__ + +>>> from a import b as __debug__ +Traceback (most recent call last): +SyntaxError: cannot assign to __debug__ + # Check that we dont raise the "trailing comma" error if there is more # input to the left of the valid part that we parsed. @@ -2186,6 +2261,10 @@ Invalid expressions in type scopes: ... SyntaxError: yield expression cannot be used within a type alias + >>> type __debug__ = int + Traceback (most recent call last): + SyntaxError: cannot assign to __debug__ + >>> class A[T]((x := 3)): ... Traceback (most recent call last): ... diff --git a/Misc/NEWS.d/next/Core and Builtins/2024-07-24-22-39-07.gh-issue-122245.LVa9v8.rst b/Misc/NEWS.d/next/Core and Builtins/2024-07-24-22-39-07.gh-issue-122245.LVa9v8.rst new file mode 100644 index 00000000000..453c45e2f7a --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2024-07-24-22-39-07.gh-issue-122245.LVa9v8.rst @@ -0,0 +1,4 @@ +Detection of writes to ``__debug__`` is moved from the compiler's codegen +stage to the symtable. This means that these errors now detected even in +code that is optimized away before codegen (such as assertions with the +:option:`-O` command line option.) diff --git a/Python/compile.c b/Python/compile.c index 9707759c99c..d07a435bdf8 100644 --- a/Python/compile.c +++ b/Python/compile.c @@ -1954,55 +1954,6 @@ compiler_default_arguments(struct compiler *c, location loc, return funcflags; } -static bool -forbidden_name(struct compiler *c, location loc, identifier name, - expr_context_ty ctx) -{ - if (ctx == Store && _PyUnicode_EqualToASCIIString(name, "__debug__")) { - compiler_error(c, loc, "cannot assign to __debug__"); - return true; - } - if (ctx == Del && _PyUnicode_EqualToASCIIString(name, "__debug__")) { - compiler_error(c, loc, "cannot delete __debug__"); - return true; - } - return false; -} - -static int -compiler_check_debug_one_arg(struct compiler *c, arg_ty arg) -{ - if (arg != NULL) { - if (forbidden_name(c, LOC(arg), arg->arg, Store)) { - return ERROR; - } - } - return SUCCESS; -} - -static int -compiler_check_debug_args_seq(struct compiler *c, asdl_arg_seq *args) -{ - if (args != NULL) { - for (Py_ssize_t i = 0, n = asdl_seq_LEN(args); i < n; i++) { - RETURN_IF_ERROR( - compiler_check_debug_one_arg(c, asdl_seq_GET(args, i))); - } - } - return SUCCESS; -} - -static int -compiler_check_debug_args(struct compiler *c, arguments_ty args) -{ - RETURN_IF_ERROR(compiler_check_debug_args_seq(c, args->posonlyargs)); - RETURN_IF_ERROR(compiler_check_debug_args_seq(c, args->args)); - RETURN_IF_ERROR(compiler_check_debug_one_arg(c, args->vararg)); - RETURN_IF_ERROR(compiler_check_debug_args_seq(c, args->kwonlyargs)); - RETURN_IF_ERROR(compiler_check_debug_one_arg(c, args->kwarg)); - return SUCCESS; -} - static int wrap_in_stopiteration_handler(struct compiler *c) { @@ -2267,7 +2218,6 @@ compiler_function(struct compiler *c, stmt_ty s, int is_async) type_params = s->v.FunctionDef.type_params; } - RETURN_IF_ERROR(compiler_check_debug_args(c, args)); RETURN_IF_ERROR(compiler_decorators(c, decos)); firstlineno = s->lineno; @@ -2910,8 +2860,6 @@ compiler_lambda(struct compiler *c, expr_ty e) arguments_ty args = e->v.Lambda.args; assert(e->kind == Lambda_kind); - RETURN_IF_ERROR(compiler_check_debug_args(c, args)); - location loc = LOC(e); funcflags = compiler_default_arguments(c, loc, args); if (funcflags == -1) { @@ -4086,10 +4034,6 @@ compiler_nameop(struct compiler *c, location loc, !_PyUnicode_EqualToASCIIString(name, "True") && !_PyUnicode_EqualToASCIIString(name, "False")); - if (forbidden_name(c, loc, name, ctx)) { - return ERROR; - } - mangled = compiler_maybe_mangle(c, name); if (!mangled) { return ERROR; @@ -4878,10 +4822,6 @@ validate_keywords(struct compiler *c, asdl_keyword_seq *keywords) if (key->arg == NULL) { continue; } - location loc = LOC(key); - if (forbidden_name(c, loc, key->arg, Store)) { - return ERROR; - } for (Py_ssize_t j = i + 1; j < nkeywords; j++) { keyword_ty other = ((keyword_ty)asdl_seq_GET(keywords, j)); if (other->arg && !PyUnicode_Compare(key->arg, other->arg)) { @@ -6135,9 +6075,6 @@ compiler_visit_expr(struct compiler *c, expr_ty e) ADDOP_NAME(c, loc, LOAD_ATTR, e->v.Attribute.attr, names); break; case Store: - if (forbidden_name(c, loc, e->v.Attribute.attr, e->v.Attribute.ctx)) { - return ERROR; - } ADDOP_NAME(c, loc, STORE_ATTR, e->v.Attribute.attr, names); break; case Del: @@ -6331,9 +6268,6 @@ compiler_annassign(struct compiler *c, stmt_ty s) } switch (targ->kind) { case Name_kind: - if (forbidden_name(c, loc, targ->v.Name.id, Store)) { - return ERROR; - } /* If we have a simple name in a module or class, store annotation. */ if (s->v.AnnAssign.simple && (c->u->u_scope_type == COMPILER_SCOPE_MODULE || @@ -6365,9 +6299,6 @@ compiler_annassign(struct compiler *c, stmt_ty s) } break; case Attribute_kind: - if (forbidden_name(c, loc, targ->v.Attribute.attr, Store)) { - return ERROR; - } if (!s->v.AnnAssign.value && check_ann_expr(c, targ->v.Attribute.value) < 0) { return ERROR; @@ -6631,9 +6562,6 @@ pattern_helper_store_name(struct compiler *c, location loc, ADDOP(c, loc, POP_TOP); return SUCCESS; } - if (forbidden_name(c, loc, n, Store)) { - return ERROR; - } // Can't assign to the same name twice: int duplicate = PySequence_Contains(pc->stores, n); RETURN_IF_ERROR(duplicate); @@ -6791,10 +6719,6 @@ validate_kwd_attrs(struct compiler *c, asdl_identifier_seq *attrs, asdl_pattern_ Py_ssize_t nattrs = asdl_seq_LEN(attrs); for (Py_ssize_t i = 0; i < nattrs; i++) { identifier attr = ((identifier)asdl_seq_GET(attrs, i)); - location loc = LOC((pattern_ty) asdl_seq_GET(patterns, i)); - if (forbidden_name(c, loc, attr, Store)) { - return ERROR; - } for (Py_ssize_t j = i + 1; j < nattrs; j++) { identifier other = ((identifier)asdl_seq_GET(attrs, j)); if (!PyUnicode_Compare(attr, other)) { diff --git a/Python/symtable.c b/Python/symtable.c index c4508cac7f5..a5fa7588785 100644 --- a/Python/symtable.c +++ b/Python/symtable.c @@ -1495,8 +1495,57 @@ error: } static int -symtable_add_def(struct symtable *st, PyObject *name, int flag, _Py_SourceLocation loc) +check_name(struct symtable *st, PyObject *name, _Py_SourceLocation loc, + expr_context_ty ctx) { + if (ctx == Store && _PyUnicode_EqualToASCIIString(name, "__debug__")) { + PyErr_SetString(PyExc_SyntaxError, "cannot assign to __debug__"); + SET_ERROR_LOCATION(st->st_filename, loc); + return 0; + } + if (ctx == Del && _PyUnicode_EqualToASCIIString(name, "__debug__")) { + PyErr_SetString(PyExc_SyntaxError, "cannot delete __debug__"); + SET_ERROR_LOCATION(st->st_filename, loc); + return 0; + } + return 1; +} + +static int +check_keywords(struct symtable *st, asdl_keyword_seq *keywords) +{ + for (Py_ssize_t i = 0; i < asdl_seq_LEN(keywords); i++) { + keyword_ty key = ((keyword_ty)asdl_seq_GET(keywords, i)); + if (key->arg && !check_name(st, key->arg, LOCATION(key), Store)) { + return 0; + } + } + return 1; +} + +static int +check_kwd_patterns(struct symtable *st, pattern_ty p) +{ + assert(p->kind == MatchClass_kind); + asdl_identifier_seq *kwd_attrs = p->v.MatchClass.kwd_attrs; + asdl_pattern_seq *kwd_patterns = p->v.MatchClass.kwd_patterns; + for (Py_ssize_t i = 0; i < asdl_seq_LEN(kwd_attrs); i++) { + _Py_SourceLocation loc = LOCATION(asdl_seq_GET(kwd_patterns, i)); + if (!check_name(st, asdl_seq_GET(kwd_attrs, i), loc, Store)) { + return 0; + } + } + return 1; +} + +static int +symtable_add_def_ctx(struct symtable *st, PyObject *name, int flag, + _Py_SourceLocation loc, expr_context_ty ctx) +{ + int write_mask = DEF_PARAM | DEF_LOCAL | DEF_IMPORT; + if ((flag & write_mask) && !check_name(st, name, loc, ctx)) { + return 0; + } if ((flag & DEF_TYPE_PARAM) && st->st_cur->ste_mangled_names != NULL) { if(PySet_Add(st->st_cur->ste_mangled_names, name) < 0) { return 0; @@ -1505,6 +1554,14 @@ symtable_add_def(struct symtable *st, PyObject *name, int flag, _Py_SourceLocati return symtable_add_def_helper(st, name, flag, st->st_cur, loc); } +static int +symtable_add_def(struct symtable *st, PyObject *name, int flag, + _Py_SourceLocation loc) +{ + return symtable_add_def_ctx(st, name, flag, loc, + flag == USE ? Load : Store); +} + static int symtable_enter_type_param_block(struct symtable *st, identifier name, void *ast, int has_defaults, int has_kwdefaults, @@ -1757,6 +1814,9 @@ symtable_visit_stmt(struct symtable *st, stmt_ty s) VISIT_SEQ(st, type_param, s->v.ClassDef.type_params); } VISIT_SEQ(st, expr, s->v.ClassDef.bases); + if (!check_keywords(st, s->v.ClassDef.keywords)) { + VISIT_QUIT(st, 0); + } VISIT_SEQ(st, keyword, s->v.ClassDef.keywords); if (!symtable_enter_block(st, s->v.ClassDef.name, ClassBlock, (void *)s, LOCATION(s))) { @@ -1871,10 +1931,11 @@ symtable_visit_stmt(struct symtable *st, stmt_ty s) VISIT(st, expr, s->v.AnnAssign.value); } break; - case AugAssign_kind: + case AugAssign_kind: { VISIT(st, expr, s->v.AugAssign.target); VISIT(st, expr, s->v.AugAssign.value); break; + } case For_kind: VISIT(st, expr, s->v.For.target); VISIT(st, expr, s->v.For.iter); @@ -2311,6 +2372,9 @@ symtable_visit_expr(struct symtable *st, expr_ty e) case Call_kind: VISIT(st, expr, e->v.Call.func); VISIT_SEQ(st, expr, e->v.Call.args); + if (!check_keywords(st, e->v.Call.keywords)) { + VISIT_QUIT(st, 0); + } VISIT_SEQ_WITH_NULL(st, keyword, e->v.Call.keywords); break; case FormattedValue_kind: @@ -2326,6 +2390,9 @@ symtable_visit_expr(struct symtable *st, expr_ty e) break; /* The following exprs can be assignment targets. */ case Attribute_kind: + if (!check_name(st, e->v.Attribute.attr, LOCATION(e), e->v.Attribute.ctx)) { + VISIT_QUIT(st, 0); + } VISIT(st, expr, e->v.Attribute.value); break; case Subscript_kind: @@ -2344,9 +2411,11 @@ symtable_visit_expr(struct symtable *st, expr_ty e) VISIT(st, expr, e->v.Slice.step); break; case Name_kind: - if (!symtable_add_def(st, e->v.Name.id, - e->v.Name.ctx == Load ? USE : DEF_LOCAL, LOCATION(e))) + if (!symtable_add_def_ctx(st, e->v.Name.id, + e->v.Name.ctx == Load ? USE : DEF_LOCAL, + LOCATION(e), e->v.Name.ctx)) { VISIT_QUIT(st, 0); + } /* Special-case super: it counts as a use of __class__ */ if (e->v.Name.ctx == Load && _PyST_IsFunctionLike(st->st_cur) && @@ -2472,19 +2541,26 @@ symtable_visit_pattern(struct symtable *st, pattern_ty p) break; case MatchStar_kind: if (p->v.MatchStar.name) { - symtable_add_def(st, p->v.MatchStar.name, DEF_LOCAL, LOCATION(p)); + if (!symtable_add_def(st, p->v.MatchStar.name, DEF_LOCAL, LOCATION(p))) { + VISIT_QUIT(st, 0); + } } break; case MatchMapping_kind: VISIT_SEQ(st, expr, p->v.MatchMapping.keys); VISIT_SEQ(st, pattern, p->v.MatchMapping.patterns); if (p->v.MatchMapping.rest) { - symtable_add_def(st, p->v.MatchMapping.rest, DEF_LOCAL, LOCATION(p)); + if (!symtable_add_def(st, p->v.MatchMapping.rest, DEF_LOCAL, LOCATION(p))) { + VISIT_QUIT(st, 0); + } } break; case MatchClass_kind: VISIT(st, expr, p->v.MatchClass.cls); VISIT_SEQ(st, pattern, p->v.MatchClass.patterns); + if (!check_kwd_patterns(st, p)) { + VISIT_QUIT(st, 0); + } VISIT_SEQ(st, pattern, p->v.MatchClass.kwd_patterns); break; case MatchAs_kind: @@ -2492,7 +2568,9 @@ symtable_visit_pattern(struct symtable *st, pattern_ty p) VISIT(st, pattern, p->v.MatchAs.pattern); } if (p->v.MatchAs.name) { - symtable_add_def(st, p->v.MatchAs.name, DEF_LOCAL, LOCATION(p)); + if (!symtable_add_def(st, p->v.MatchAs.name, DEF_LOCAL, LOCATION(p))) { + VISIT_QUIT(st, 0); + } } break; case MatchOr_kind: