diff options
Diffstat (limited to 'Python/ast.c')
| -rw-r--r-- | Python/ast.c | 109 |
1 files changed, 74 insertions, 35 deletions
diff --git a/Python/ast.c b/Python/ast.c index f155366..a2b69f5 100644 --- a/Python/ast.c +++ b/Python/ast.c @@ -329,6 +329,19 @@ static int set_context(expr_ty e, expr_context_ty ctx, const node *n) { asdl_seq *s = NULL; + /* If a particular expression type can't be used for assign / delete, + set expr_name to its name and an error message will be generated. + */ + const char* expr_name = NULL; + + /* The ast defines augmented store and load contexts, but the + implementation here doesn't actually use them. The code may be + a little more complex than necessary as a result. It also means + that expressions in an augmented assignment have no context. + Consider restructuring so that augmented assignment uses + set_context(), too + */ + assert(ctx != AugStore && ctx != AugLoad); switch (e->kind) { case Attribute_kind: @@ -358,30 +371,50 @@ set_context(expr_ty e, expr_context_ty ctx, const node *n) e->v.Tuple.ctx = ctx; s = e->v.Tuple.elts; break; + case Lambda_kind: + expr_name = "lambda"; + break; case Call_kind: - if (ctx == Store) - return ast_error(n, "can't assign to function call"); - else if (ctx == Del) - return ast_error(n, "can't delete function call"); - else - return ast_error(n, "unexpected operation on function call"); + expr_name = "function call"; break; + case BoolOp_kind: case BinOp_kind: - return ast_error(n, "can't assign to operator"); + case UnaryOp_kind: + expr_name = "operator"; + break; case GeneratorExp_kind: - return ast_error(n, "assignment to generator expression " - "not possible"); + expr_name = "generator expression"; + break; + case ListComp_kind: + expr_name = "list comprehension"; + break; + case Dict_kind: case Num_kind: case Str_kind: - return ast_error(n, "can't assign to literal"); - default: { - char buf[300]; - PyOS_snprintf(buf, sizeof(buf), - "unexpected expression in assignment %d (line %d)", - e->kind, e->lineno); - return ast_error(n, buf); - } + expr_name = "literal"; + break; + case Compare_kind: + expr_name = "comparison"; + break; + case Repr_kind: + expr_name = "repr"; + break; + default: + PyErr_Format(PyExc_SystemError, + "unexpected expression in assignment %d (line %d)", + e->kind, e->lineno); + return 0; } + /* Check for error string set by switch */ + if (expr_name) { + char buf[300]; + PyOS_snprintf(buf, sizeof(buf), + "can't %s %s", + ctx == Store ? "assign to" : "delete", + expr_name); + return ast_error(n, buf); + } + /* If the LHS is a list or tuple, we need to set the assignment context for all the tuple elements. */ @@ -699,12 +732,8 @@ ast_for_decorator(struct compiling *c, const node *n) expr_ty name_expr; REQ(n, decorator); - - if ((NCH(n) < 3 && NCH(n) != 5 && NCH(n) != 6) - || TYPE(CHILD(n, 0)) != AT || TYPE(RCHILD(n, -1)) != NEWLINE) { - ast_error(n, "Invalid decorator node"); - return NULL; - } + REQ(CHILD(n, 0), AT); + REQ(RCHILD(n, -1), NEWLINE); name_expr = ast_for_dotted_name(c, CHILD(n, 1)); if (!name_expr) @@ -1610,7 +1639,7 @@ ast_for_call(struct compiling *c, const node *n, expr_ty func) } } if (ngens > 1 || (ngens && (nargs || nkeywords))) { - ast_error(n, "Generator expression must be parenthesised " + ast_error(n, "Generator expression must be parenthesized " "if not sole argument"); return NULL; } @@ -1779,18 +1808,28 @@ ast_for_expr_stmt(struct compiling *c, const node *n) if (!expr1) return NULL; - if (expr1->kind == GeneratorExp_kind) { - ast_error(ch, "augmented assignment to generator " - "expression not possible"); - return NULL; + // TODO(jhylton): Figure out why set_context() can't be used here. + switch (expr1->kind) { + case GeneratorExp_kind: + ast_error(ch, "augmented assignment to generator " + "expression not possible"); + return NULL; + case Name_kind: { + const char *var_name = PyString_AS_STRING(expr1->v.Name.id); + if (var_name[0] == 'N' && !strcmp(var_name, "None")) { + ast_error(ch, "assignment to None"); + return NULL; + } + break; + } + case Attribute_kind: + case Subscript_kind: + break; + default: + ast_error(ch, "illegal expression for augmented " + "assignment"); + return NULL; } - if (expr1->kind == Name_kind) { - char *var_name = PyString_AS_STRING(expr1->v.Name.id); - if (var_name[0] == 'N' && !strcmp(var_name, "None")) { - ast_error(ch, "assignment to None"); - return NULL; - } - } ch = CHILD(n, 2); if (TYPE(ch) == testlist) |