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Some code and documentation improvements.

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* data/c.m4 (b4_table_value_equals): New macro to capture
some repeated code.
* data/glr.c (yyis_pact_ninf): Use it here.
(yyis_table_ninf): Likewise.
(yyreportSyntaxError): Improve internal comments.
* data/yacc.c (yyis_pact_ninf): New macro copied from glr.c.
Use it everywhere possible.
(yyis_table_ninf): Likewise.
(yysyntax_error): Improve internal comments.
* data/lalr1.cc (yysyntax_error_): Likewise.
* data/lalr1.java (yysyntax_error): Likewise.
* src/tables.h: Improve comments about yypact, yytable, etc.
This commit is contained in:
Joel E. Denny
2009-08-25 01:12:37 -04:00
parent e6c849d82a
commit 8741288212
7 changed files with 56 additions and 15 deletions
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10
data/c.m4
View File

@@ -157,6 +157,16 @@ m4_define([b4_int_type_for],
[b4_int_type($1_min, $1_max)])
# b4_table_value_equals(TABLE, VALUE, LITERAL)
# --------------------------------------------
# Without inducing a comparison warning from the compiler, check if the
# literal value LITERAL equals VALUE from table TABLE, which must have
# TABLE_min and TABLE_max defined.
m4_define([b4_table_value_equals],
[m4_if(m4_eval($3 < m4_indir([b4_]$1[_min])
|| m4_indir([b4_]$1[_max]) < $3), [1],
[[YYID (0)]],
[[((]$2[) == (]$3[))]])])
## ---------##
## Values. ##

11
data/glr.c
View File

@@ -954,9 +954,7 @@ yylhsNonterm (yyRuleNum yyrule)
}
#define yyis_pact_ninf(yystate) \
]m4_if(m4_eval(b4_pact_ninf < b4_pact_min), [1],
[0],
[((yystate) == YYPACT_NINF)])[
]b4_table_value_equals([[pact]], [[yystate]], [b4_pact_ninf])[
/** True iff LR state STATE has only a default reduction (regardless
* of token). */
@@ -974,9 +972,7 @@ yydefaultAction (yyStateNum yystate)
}
#define yyis_table_ninf(yytable_value) \
]m4_if(m4_eval(b4_table_ninf < b4_table_min), [1],
[YYID (0)],
[((yytable_value) == YYTABLE_NINF)])[
]b4_table_value_equals([[table]], [[yytable_value]], [b4_table_ninf])[
/** Set *YYACTION to the action to take in YYSTATE on seeing YYTOKEN.
* Result R means
@@ -2048,7 +2044,8 @@ yyreportSyntaxError (yyGLRStack* yystackp]b4_user_formals[)
char const *yyarg[YYERROR_VERBOSE_ARGS_MAXIMUM];
/* Start YYX at -YYN if negative to avoid negative indexes in
YYCHECK. */
YYCHECK. In other words, skip the first -YYN actions for this
state because they are default actions. */
int yyxbegin = yyn < 0 ? -yyn : 0;
/* Stay within bounds of both yycheck and yytname. */

3
data/lalr1.cc
View File

@@ -954,7 +954,8 @@ b4_error_verbose_if([state_type yystate, int yytoken],
if (yypact_ninf_ < yyn && yyn <= yylast_)
{
/* Start YYX at -YYN if negative to avoid negative indexes in
YYCHECK. */
YYCHECK. In other words, skip the first -YYN actions for this
state because they are default actions. */
int yyxbegin = yyn < 0 ? -yyn : 0;
/* Stay within bounds of both yycheck and yytname. */

3
data/lalr1.java
View File

@@ -735,7 +735,8 @@ m4_popdef([b4_at_dollar])])dnl
StringBuffer res;
/* Start YYX at -YYN if negative to avoid negative indexes in
YYCHECK. */
YYCHECK. In other words, skip the first -YYN actions for this
state because they are default actions. */
int yyxbegin = yyn < 0 ? -yyn : 0;
/* Stay within bounds of both yycheck and yytname. */

15
data/yacc.c
View File

@@ -525,8 +525,14 @@ static const ]b4_int_type_for([b4_toknum])[ yytoknum[] =
#define YYPACT_NINF ]b4_pact_ninf[
#define yyis_pact_ninf(yystate) \
]b4_table_value_equals([[pact]], [[yystate]], [b4_pact_ninf])[
#define YYTABLE_NINF ]b4_table_ninf[
#define yyis_table_ninf(yytable_value) \
]b4_table_value_equals([[table]], [[yytable_value]], [b4_table_ninf])[
]b4_parser_tables_define[
#define yyerrok (yyerrstatus = 0)
@@ -848,7 +854,8 @@ yysyntax_error (char *yyresult, int yystate, int yytoken)
char const *yyarg[YYERROR_VERBOSE_ARGS_MAXIMUM];
/* Start YYX at -YYN if negative to avoid negative indexes in
YYCHECK. */
YYCHECK. In other words, skip the first -YYN actions for this
state because they are default actions. */
int yyxbegin = yyn < 0 ? -yyn : 0;
/* Stay within bounds of both yycheck and yytname. */
@@ -1271,7 +1278,7 @@ yybackup:
/* First try to decide what to do without reference to lookahead token. */
yyn = yypact[yystate];
if (yyn == YYPACT_NINF)
if (yyis_pact_ninf (yyn))
goto yydefault;
/* Not known => get a lookahead token if don't already have one. */
@@ -1321,7 +1328,7 @@ yyread_pushed_token:]])[
yyn = yytable[yyn];
if (yyn <= 0)
{
if (yyn == 0 || yyn == YYTABLE_NINF)
if (yyn == 0 || yyis_table_ninf (yyn))
goto yyerrlab;
yyn = -yyn;
goto yyreduce;
@@ -1505,7 +1512,7 @@ yyerrlab1:
for (;;)
{
yyn = yypact[yystate];
if (yyn != YYPACT_NINF)
if (!yyis_pact_ninf (yyn))
{
yyn += YYTERROR;
if (0 <= yyn && yyn <= YYLAST && yycheck[yyn] == YYTERROR)