diff options
Diffstat (limited to 'src/parse-gram.y')
| -rw-r--r-- | src/parse-gram.y | 29 |
1 files changed, 25 insertions, 4 deletions
diff --git a/src/parse-gram.y b/src/parse-gram.y index f79b0e92..514b5d79 100644 --- a/src/parse-gram.y +++ b/src/parse-gram.y @@ -56,10 +56,28 @@ static char const *char_name (char); static int current_prec = 0; static location current_lhs_location; static named_ref *current_lhs_named_ref; - static symbol *current_lhs; + static symbol *current_lhs_symbol; static symbol_class current_class = unknown_sym; static uniqstr current_type = NULL; + /** Set the new current left-hand side symbol, possibly common + * to several right-hand side parts of rule. + */ + static + void + current_lhs(symbol *sym, location loc, named_ref *ref) + { + current_lhs_symbol = sym; + current_lhs_location = loc; + /* In order to simplify memory management, named references for lhs + are always assigned by deep copy into the current symbol_list + node. This is because a single named-ref in the grammar may + result in several uses when the user factors lhs between several + rules using "|". Therefore free the parser's original copy. */ + free (current_lhs_named_ref); + current_lhs_named_ref = ref; + } + #define YYTYPE_INT16 int_fast16_t #define YYTYPE_INT8 int_fast8_t #define YYTYPE_UINT16 uint_fast16_t @@ -569,8 +587,11 @@ rules_or_grammar_declaration: ; rules: - id_colon named_ref.opt { current_lhs = $1; current_lhs_location = @1; - current_lhs_named_ref = $2; } rhses.1 + id_colon named_ref.opt { current_lhs ($1, @1, $2); } rhses.1 + { + /* Free the current lhs. */ + current_lhs (0, @1, 0); + } ; rhses.1: @@ -581,7 +602,7 @@ rhses.1: rhs: /* Nothing. */ - { grammar_current_rule_begin (current_lhs, current_lhs_location, + { grammar_current_rule_begin (current_lhs_symbol, current_lhs_location, current_lhs_named_ref); } | rhs symbol named_ref.opt { grammar_current_rule_symbol_append ($2, @2, $3); } |