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Actually handle the yytable zero value correctly this time.

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* data/bison.m4 (b4_integral_parser_tables_map): Don't mention
zero values in the YYTABLE comments.
* data/glr.c (yytable_value_is_error): Don't check for zero
value.
* data/lalr1.cc (yy_table_value_is_error_): Likewise.
* data/yacc.c (yytable_value_is_error): Likewise.
* data/lalr1.java (yy_table_value_is_error_): Likewise.
(yysyntax_error): Fix typo in code: use yytable_ not yycheck_.
* src/tables.h: In header comments, explain why it's useless to
check for a zero value in yytable.
This commit is contained in:
Joel E. Denny
2009-08-26 02:40:38 -04:00
parent f2b30bdf37
commit aa0cb40d61
10 changed files with 353 additions and 332 deletions
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633
src/parse-gram.c
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File diff suppressed because it is too large Load Diff

6
src/parse-gram.h
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@@ -1,4 +1,4 @@
/* A Bison parser, made by GNU Bison 2.4.388-53f03. */
/* A Bison parser, made by GNU Bison 2.4.390-0aaa. */
/* Interface for Bison's Yacc-like parsers in C
@@ -157,7 +157,7 @@
#if ! defined YYSTYPE && ! defined YYSTYPE_IS_DECLARED
typedef union YYSTYPE
{
/* Line 1609 of yacc.c */
/* Line 1608 of yacc.c */
#line 94 "parse-gram.y"
symbol *symbol;
@@ -171,7 +171,7 @@ typedef union YYSTYPE
named_ref *named_ref;
/* Line 1609 of yacc.c */
/* Line 1608 of yacc.c */
#line 176 "src/parse-gram.h"
} YYSTYPE;
# define YYSTYPE_IS_TRIVIAL 1

2
src/tables.c
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@@ -126,7 +126,7 @@ static int table_size = 32768;
base_number *table;
base_number *check;
/* The value used in TABLE to denote explicit syntax errors
(%nonassoc), a negative infinite. First defaults to ACTION_NUMBER_MININUM,
(%nonassoc), a negative infinite. First defaults to ACTION_NUMBER_MINIMUM,
but in order to keep small tables, renumbered as TABLE_ERROR, which
is the smallest (non error) value minus 1. */
base_number table_ninf = 0;

14
src/tables.h
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@@ -48,7 +48,7 @@
YYFINAL = the state number of the termination state.
YYTABLE = a vector filled with portions for different uses, found
via YYPACT and YYPGOTO.
via YYPACT and YYPGOTO, described below.
YYLAST ( = high) the number of the last element of YYTABLE, i.e.,
sizeof (YYTABLE) - 1.
@@ -87,7 +87,7 @@
If the value is negative, it is minus a rule number to reduce by.
If the value is zero or YYTABLE_NINF, it's a syntax error.
If the value is YYTABLE_NINF, it's a syntax error.
YYPGOTO[I] = the index in YYTABLE of the portion describing what to
do after reducing a rule that derives variable I + NTOKENS. This
@@ -99,6 +99,16 @@
YYCHECK[YYPGOTO[I] + S] != S), then the default state (that is,
YYDEFGOTO[I]) should be used instead of YYTABLE. Otherwise,
YYTABLE[YYPGOTO[I] + S] is the state to go to even if YYPGOTO[I] < 0.
When the above YYPACT, YYPGOTO, and YYCHECK tests determine that a
value from YYTABLE should be used, that value is never zero, so it is
useless to check for zero. When those tests indicate that the value
from YYDEFACT or YYDEFGOTO should be used instead, the value from
YYTABLE *might* be zero, which, as a consequence of the way in which
the tables are constructed, also happens to indicate that YYDEFACT or
YYDEFGOTO should be used. However, the YYTABLE value cannot be
trusted when the YYDEFACT or YYDEFGOTO value should be used. In
summary, forget about zero values in YYTABLE.
*/
extern int nvectors;