diff options
| -rw-r--r-- | Lib/test/test_ast.py | 6 | ||||
| -rw-r--r-- | Python/ast.c | 48 |
2 files changed, 33 insertions, 21 deletions
diff --git a/Lib/test/test_ast.py b/Lib/test/test_ast.py index 925bb88..1f4257b 100644 --- a/Lib/test/test_ast.py +++ b/Lib/test/test_ast.py @@ -1627,7 +1627,11 @@ class ASTValidatorTests(unittest.TestCase): ), ast.MatchOr( [pattern_1, pattern_x, ast.MatchSingleton('xxx')] - ) + ), + ast.MatchAs(name="_"), + ast.MatchStar(name="x"), + ast.MatchSequence([ast.MatchStar("_")]), + ast.MatchMapping([], [], rest="_"), ] def test_match_validation_pattern(self): diff --git a/Python/ast.c b/Python/ast.c index 0a306c0..2113124 100644 --- a/Python/ast.c +++ b/Python/ast.c @@ -20,7 +20,7 @@ static int validate_patterns(struct validator *, asdl_pattern_seq *, int); static int _validate_nonempty_seq(asdl_seq *, const char *, const char *); static int validate_stmt(struct validator *, stmt_ty); static int validate_expr(struct validator *, expr_ty, expr_context_ty); -static int validate_pattern(struct validator *, pattern_ty); +static int validate_pattern(struct validator *, pattern_ty, int); static int validate_name(PyObject *name) @@ -493,7 +493,17 @@ validate_pattern_match_value(struct validator *state, expr_ty exp) } static int -validate_pattern(struct validator *state, pattern_ty p) +validate_capture(PyObject *name) +{ + if (_PyUnicode_EqualToASCIIString(name, "_")) { + PyErr_Format(PyExc_ValueError, "can't capture name '_' in patterns"); + return 0; + } + return validate_name(name); +} + +static int +validate_pattern(struct validator *state, pattern_ty p, int star_ok) { int ret = -1; if (++state->recursion_depth > state->recursion_limit) { @@ -501,8 +511,6 @@ validate_pattern(struct validator *state, pattern_ty p) "maximum recursion depth exceeded during compilation"); return 0; } - // Coming soon: https://bugs.python.org/issue43897 (thanks Batuhan)! - // TODO: Ensure no subnodes use "_" as an ordinary identifier switch (p->kind) { case MatchValue_kind: ret = validate_pattern_match_value(state, p->v.MatchValue.value); @@ -525,7 +533,7 @@ validate_pattern(struct validator *state, pattern_ty p) break; } - if (p->v.MatchMapping.rest && !validate_name(p->v.MatchMapping.rest)) { + if (p->v.MatchMapping.rest && !validate_capture(p->v.MatchMapping.rest)) { ret = 0; break; } @@ -575,16 +583,16 @@ validate_pattern(struct validator *state, pattern_ty p) else { PyErr_SetString(PyExc_ValueError, "MatchClass cls field can only contain Name or Attribute nodes."); - state->recursion_depth--; - return 0; + ret = 0; + break; } } for (Py_ssize_t i = 0; i < asdl_seq_LEN(p->v.MatchClass.kwd_attrs); i++) { PyObject *identifier = asdl_seq_GET(p->v.MatchClass.kwd_attrs, i); if (!validate_name(identifier)) { - state->recursion_depth--; - return 0; + ret = 0; + break; } } @@ -596,10 +604,15 @@ validate_pattern(struct validator *state, pattern_ty p) ret = validate_patterns(state, p->v.MatchClass.kwd_patterns, /*star_ok=*/0); break; case MatchStar_kind: - ret = p->v.MatchStar.name == NULL || validate_name(p->v.MatchStar.name); + if (!star_ok) { + PyErr_SetString(PyExc_ValueError, "can't use MatchStar here"); + ret = 0; + break; + } + ret = p->v.MatchStar.name == NULL || validate_capture(p->v.MatchStar.name); break; case MatchAs_kind: - if (p->v.MatchAs.name && !validate_name(p->v.MatchAs.name)) { + if (p->v.MatchAs.name && !validate_capture(p->v.MatchAs.name)) { ret = 0; break; } @@ -609,10 +622,10 @@ validate_pattern(struct validator *state, pattern_ty p) else if (p->v.MatchAs.name == NULL) { PyErr_SetString(PyExc_ValueError, "MatchAs must specify a target name if a pattern is given"); - return 0; + ret = 0; } else { - ret = validate_pattern(state, p->v.MatchAs.pattern); + ret = validate_pattern(state, p->v.MatchAs.pattern, /*star_ok=*/0); } break; case MatchOr_kind: @@ -759,7 +772,7 @@ validate_stmt(struct validator *state, stmt_ty stmt) } for (i = 0; i < asdl_seq_LEN(stmt->v.Match.cases); i++) { match_case_ty m = asdl_seq_GET(stmt->v.Match.cases, i); - if (!validate_pattern(state, m->pattern) + if (!validate_pattern(state, m->pattern, /*star_ok=*/0) || (m->guard && !validate_expr(state, m->guard, Load)) || !validate_body(state, m->body, "match_case")) { return 0; @@ -894,12 +907,7 @@ validate_patterns(struct validator *state, asdl_pattern_seq *patterns, int star_ Py_ssize_t i; for (i = 0; i < asdl_seq_LEN(patterns); i++) { pattern_ty pattern = asdl_seq_GET(patterns, i); - if (pattern->kind == MatchStar_kind && !star_ok) { - PyErr_SetString(PyExc_ValueError, - "Can't use MatchStar within this sequence of patterns"); - return 0; - } - if (!validate_pattern(state, pattern)) { + if (!validate_pattern(state, pattern, star_ok)) { return 0; } } |