diff options
Diffstat (limited to 'gcc/c-parser.c')
| -rw-r--r-- | gcc/c-parser.c | 74 |
1 files changed, 65 insertions, 9 deletions
diff --git a/gcc/c-parser.c b/gcc/c-parser.c index 5293547..1e32b5b 100644 --- a/gcc/c-parser.c +++ b/gcc/c-parser.c @@ -280,6 +280,8 @@ typedef struct c_parser GTY(()) /* True if we're processing a pragma, and shouldn't automatically consume CPP_PRAGMA_EOL. */ BOOL_BITFIELD in_pragma : 1; + /* True if we're parsing the outermost block of an if statement. */ + BOOL_BITFIELD in_if_block : 1; /* True if we want to lex an untranslated string. */ BOOL_BITFIELD lex_untranslated_string : 1; /* Objective-C specific parser/lexer information. */ @@ -3541,6 +3543,20 @@ c_parser_compound_statement_nostart (c_parser *parser) c_parser_error (parser, "expected declaration or statement"); return; } + else if (c_parser_next_token_is_keyword (parser, RID_ELSE)) + { + if (parser->in_if_block) + { + error ("%H""expected %<}%> before %<else%>", &loc); + return; + } + else + { + error ("%H%<else%> without a previous %<if%>", &loc); + c_parser_consume_token (parser); + continue; + } + } else { statement: @@ -3740,6 +3756,8 @@ c_parser_statement_after_labels (c_parser *parser) { location_t loc = c_parser_peek_token (parser)->location; tree stmt = NULL_TREE; + bool in_if_block = parser->in_if_block; + parser->in_if_block = false; switch (c_parser_peek_token (parser)->type) { case CPP_OPEN_BRACE: @@ -3873,6 +3891,8 @@ c_parser_statement_after_labels (c_parser *parser) earlier? */ if (stmt && CAN_HAVE_LOCATION_P (stmt)) SET_EXPR_LOCATION (stmt, loc); + + parser->in_if_block = in_if_block; } /* Parse a parenthesized condition from an if, do or while statement. @@ -3906,11 +3926,13 @@ c_parser_c99_block_statement (c_parser *parser) return c_end_compound_stmt (block, flag_isoc99); } -/* Parse the body of an if statement or the else half thereof. This - is just parsing a statement but (a) it is a block in C99, (b) we - track whether the body is an if statement for the sake of - -Wparentheses warnings, (c) we handle an empty body specially for - the sake of -Wempty-body warnings. */ +/* Parse the body of an if statement. This is just parsing a + statement but (a) it is a block in C99, (b) we track whether the + body is an if statement for the sake of -Wparentheses warnings, (c) + we handle an empty body specially for the sake of -Wempty-body + warnings, and (d) we call parser_compound_statement directly + because c_parser_statement_after_labels resets + parser->in_if_block. */ static tree c_parser_if_body (c_parser *parser, bool *if_p) @@ -3923,8 +3945,37 @@ c_parser_if_body (c_parser *parser, bool *if_p) c_parser_label (parser); *if_p = c_parser_next_token_is_keyword (parser, RID_IF); if (c_parser_next_token_is (parser, CPP_SEMICOLON)) - add_stmt (build_empty_stmt ()); - c_parser_statement_after_labels (parser); + { + add_stmt (build_empty_stmt ()); + c_parser_consume_token (parser); + } + else if (c_parser_next_token_is (parser, CPP_OPEN_BRACE)) + add_stmt (c_parser_compound_statement (parser)); + else + c_parser_statement_after_labels (parser); + return c_end_compound_stmt (block, flag_isoc99); +} + +/* Parse the else body of an if statement. This is just parsing a + statement but (a) it is a block in C99, (b) we handle an empty body + specially for the sake of -Wempty-body warnings. */ + +static tree +c_parser_else_body (c_parser *parser) +{ + tree block = c_begin_compound_stmt (flag_isoc99); + while (c_parser_next_token_is_keyword (parser, RID_CASE) + || c_parser_next_token_is_keyword (parser, RID_DEFAULT) + || (c_parser_next_token_is (parser, CPP_NAME) + && c_parser_peek_2nd_token (parser)->type == CPP_COLON)) + c_parser_label (parser); + if (c_parser_next_token_is (parser, CPP_SEMICOLON)) + { + add_stmt (build_empty_stmt ()); + c_parser_consume_token (parser); + } + else + c_parser_statement_after_labels (parser); return c_end_compound_stmt (block, flag_isoc99); } @@ -3941,18 +3992,23 @@ c_parser_if_statement (c_parser *parser) tree block; location_t loc; tree cond; - bool first_if = false, second_if = false; + bool first_if = false; tree first_body, second_body; + bool in_if_block; + gcc_assert (c_parser_next_token_is_keyword (parser, RID_IF)); c_parser_consume_token (parser); block = c_begin_compound_stmt (flag_isoc99); loc = c_parser_peek_token (parser)->location; cond = c_parser_paren_condition (parser); + in_if_block = parser->in_if_block; + parser->in_if_block = true; first_body = c_parser_if_body (parser, &first_if); + parser->in_if_block = in_if_block; if (c_parser_next_token_is_keyword (parser, RID_ELSE)) { c_parser_consume_token (parser); - second_body = c_parser_if_body (parser, &second_if); + second_body = c_parser_else_body (parser); } else second_body = NULL_TREE; |