diff options
Diffstat (limited to 'gcc/cp/parser.c')
| -rw-r--r-- | gcc/cp/parser.c | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c index e1b320ab1ab..d437cc5e623 100644 --- a/gcc/cp/parser.c +++ b/gcc/cp/parser.c @@ -4207,6 +4207,144 @@ cp_parser_statement_expr (cp_parser *parser) /* Expressions [gram.expr] */ + +/* A helper function for cp_parser_fold_operator. Consume the token + and return the matched tree CODE. */ +static inline int +cp_parser_match_fold_op (cp_parser *parser, int code) +{ + cp_lexer_consume_token (parser->lexer); + return code; +} + +/* Parse a fold-operator. + + fold-operator: + - * / % ^ & | = < > << >> + = -= *= /= %= ^= &= |= <<= >>= + == != <= >= && || , .* ->* + + This returns the tree code corresponding to the matched operator + as an int. When the current token matches a compound assignment + opertor, the resulting tree code is the negative value of the + non-assignment operator. */ + +static int +cp_parser_fold_operator (cp_parser *parser) +{ + cp_token* token = cp_lexer_peek_token (parser->lexer); + switch (token->type) + { + case CPP_PLUS: return cp_parser_match_fold_op (parser, PLUS_EXPR); + case CPP_MINUS: return cp_parser_match_fold_op (parser, MINUS_EXPR); + case CPP_MULT: return cp_parser_match_fold_op (parser, MULT_EXPR); + case CPP_DIV: return cp_parser_match_fold_op (parser, TRUNC_DIV_EXPR); + case CPP_MOD: return cp_parser_match_fold_op (parser, TRUNC_MOD_EXPR); + case CPP_XOR: return cp_parser_match_fold_op (parser, BIT_XOR_EXPR); + case CPP_AND: return cp_parser_match_fold_op (parser, BIT_AND_EXPR); + case CPP_OR: return cp_parser_match_fold_op (parser, BIT_IOR_EXPR); + case CPP_LSHIFT: return cp_parser_match_fold_op (parser, LSHIFT_EXPR); + case CPP_RSHIFT: return cp_parser_match_fold_op (parser, RSHIFT_EXPR); + + case CPP_EQ: return cp_parser_match_fold_op (parser, -NOP_EXPR); + case CPP_PLUS_EQ: return cp_parser_match_fold_op (parser, -PLUS_EXPR); + case CPP_MINUS_EQ: return cp_parser_match_fold_op (parser, -MINUS_EXPR); + case CPP_MULT_EQ: return cp_parser_match_fold_op (parser, -MULT_EXPR); + case CPP_DIV_EQ: return cp_parser_match_fold_op (parser, -TRUNC_DIV_EXPR); + case CPP_MOD_EQ: return cp_parser_match_fold_op (parser, -TRUNC_MOD_EXPR); + case CPP_XOR_EQ: return cp_parser_match_fold_op (parser, -BIT_XOR_EXPR); + case CPP_AND_EQ: return cp_parser_match_fold_op (parser, -BIT_AND_EXPR); + case CPP_OR_EQ: return cp_parser_match_fold_op (parser, -BIT_IOR_EXPR); + case CPP_LSHIFT_EQ: return cp_parser_match_fold_op (parser, -LSHIFT_EXPR); + case CPP_RSHIFT_EQ: return cp_parser_match_fold_op (parser, -RSHIFT_EXPR); + + case CPP_EQ_EQ: return cp_parser_match_fold_op (parser, EQ_EXPR); + case CPP_NOT_EQ: return cp_parser_match_fold_op (parser, NE_EXPR); + case CPP_LESS: return cp_parser_match_fold_op (parser, LT_EXPR); + case CPP_GREATER: return cp_parser_match_fold_op (parser, GT_EXPR); + case CPP_LESS_EQ: return cp_parser_match_fold_op (parser, LE_EXPR); + case CPP_GREATER_EQ: return cp_parser_match_fold_op (parser, GE_EXPR); + + case CPP_AND_AND: return cp_parser_match_fold_op (parser, TRUTH_ANDIF_EXPR); + case CPP_OR_OR: return cp_parser_match_fold_op (parser, TRUTH_ORIF_EXPR); + + case CPP_COMMA: return cp_parser_match_fold_op (parser, COMPOUND_EXPR); + + case CPP_DOT_STAR: return cp_parser_match_fold_op (parser, DOTSTAR_EXPR); + case CPP_DEREF_STAR: return cp_parser_match_fold_op (parser, MEMBER_REF); + + default: return ERROR_MARK; + } +} + +/* Parse a fold-expression. + + fold-expression: + ( ... folding-operator cast-expression) + ( cast-expression folding-operator ... ) + ( cast-expression folding operator ... folding-operator cast-expression) + + Note that the '(' and ')' are matched in primary expression. */ + +static tree +cp_parser_fold_expression (cp_parser *parser) { + cp_id_kind pidk; + + // Left fold + if (cp_lexer_next_token_is (parser->lexer, CPP_ELLIPSIS)) + { + cp_lexer_consume_token (parser->lexer); + int op = cp_parser_fold_operator (parser); + if (op == ERROR_MARK) + { + cp_parser_error (parser, "expected cast-expression"); + return error_mark_node; + } + + tree expr = cp_parser_cast_expression (parser, false, false, false, &pidk); + if (expr == error_mark_node) + return error_mark_node; + return finish_left_unary_fold_expr (expr, op); + } + + tree expr1 = cp_parser_cast_expression (parser, false, false, false, &pidk); + if (expr1 == error_mark_node) + return error_mark_node; + + const cp_token* token = cp_lexer_peek_token (parser->lexer); + int op = cp_parser_fold_operator (parser); + if (op == ERROR_MARK) + { + cp_parser_error (parser, "expected cast-expression"); + return error_mark_node; + } + + if (cp_lexer_next_token_is_not (parser->lexer, CPP_ELLIPSIS)) + { + cp_parser_error (parser, "expected ..."); + return error_mark_node; + } + cp_lexer_consume_token (parser->lexer); + + // Right fold + if (cp_lexer_next_token_is (parser->lexer, CPP_CLOSE_PAREN)) + return finish_right_unary_fold_expr (expr1, op); + + if (cp_lexer_next_token_is_not (parser->lexer, token->type)) + { + error ("mismatched fold-operator in cast expression"); + return error_mark_node; + } + cp_lexer_consume_token (parser->lexer); + + // Binary left or right fold + tree expr2 = cp_parser_cast_expression (parser, false, false, false, &pidk); + if (expr2 == error_mark_node) + return error_mark_node; + tree t = finish_binary_fold_expr (expr1, expr2, op); + return t; +} + /* Parse a primary-expression. primary-expression: @@ -4413,6 +4551,16 @@ cp_parser_primary_expression (cp_parser *parser, = parser->greater_than_is_operator_p; parser->greater_than_is_operator_p = true; + // Try to parse a fold-expression. + cp_parser_parse_tentatively (parser); + tree fold = cp_parser_fold_expression (parser); + if (cp_parser_parse_definitely (parser)) + { + if (!cp_parser_require (parser, CPP_CLOSE_PAREN, RT_CLOSE_PAREN)) + cp_parser_skip_to_end_of_statement (parser); + return fold; + } + /* Parse the parenthesized expression. */ expr = cp_parser_expression (parser, idk, cast_p, decltype_p); /* Let the front end know that this expression was |