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Fix bug that mistakes braced code in a declaration in the rules section

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to be a rule action.  Mentioned at
<http://lists.gnu.org/archive/html/bison-patches/2006-06/msg00105.html>.
* src/scan-gram.l: Move midrule action detection from the start of the
scanning of any braced code to...
* src/parse-gram.y (rhs): ... the parsing of braced code as a rule
action.  For readability, use $2 and @2 rather than the equivalent
global variables.
* tests/regression.at (Braced code in declaration in rules section):
New test to catch the error fixed by the above patch.

Work on code readability some.
* src/scan-code.l (current_rule): Get rid of this misleading and
redundant declaration: it's actually extern'ed in reader.h.
(YY_DECL, code_lex, handle_action_dollar, handle_action_at,
translate_action): Add a rule argument and use it instead of the global
current_rule.
(translate_rule_action): This already receives current_rule through an
argument, so pass it on to translate_action instead of assigning
current_rule to current_rule.
(translate_symbol_action, translate_code): Pass rule = NULL to
translate_action.
This commit is contained in:
Joel E. Denny
2006-06-24 06:51:27 +00:00
parent 34f98f46ee
commit 4210cd0bfc
6 changed files with 146 additions and 44 deletions
Download Patch File Download Diff File Expand all files Collapse all files

25
ChangeLog
View File

@@ -1,3 +1,28 @@
2006-06-24 Joel E. Denny <jdenny@ces.clemson.edu>
Fix bug that mistakes braced code in a declaration in the rules section
to be a rule action. Mentioned at
<http://lists.gnu.org/archive/html/bison-patches/2006-06/msg00105.html>.
* src/scan-gram.l: Move midrule action detection from the start of the
scanning of any braced code to...
* src/parse-gram.y (rhs): ... the parsing of braced code as a rule
action. For readability, use $2 and @2 rather than the equivalent
global variables.
* tests/regression.at (Braced code in declaration in rules section):
New test to catch the error fixed by the above patch.
Work on code readability some.
* src/scan-code.l (current_rule): Get rid of this misleading and
redundant declaration: it's actually extern'ed in reader.h.
(YY_DECL, code_lex, handle_action_dollar, handle_action_at,
translate_action): Add a rule argument and use it instead of the global
current_rule.
(translate_rule_action): This already receives current_rule through an
argument, so pass it on to translate_action instead of assigning
current_rule to current_rule.
(translate_symbol_action, translate_code): Pass rule = NULL to
translate_action.
2006-06-23 Joel E. Denny <jdenny@ces.clemson.edu>
Rename %before-definitions to %start-header and %after-definitions to

33
src/parse-gram.c
View File

@@ -654,8 +654,8 @@ static const yytype_uint16 yyrline[] =
305, 309, 323, 324, 328, 350, 350, 355, 355, 360,
370, 385, 386, 387, 391, 392, 397, 398, 403, 407,
412, 418, 424, 435, 436, 445, 446, 452, 453, 454,
461, 461, 465, 466, 467, 472, 473, 475, 478, 480,
482, 495, 497, 506, 511, 512, 517, 526, 531, 533
461, 461, 465, 466, 467, 472, 473, 475, 481, 483,
485, 498, 500, 509, 514, 515, 520, 529, 534, 536
};
#endif
@@ -2173,32 +2173,35 @@ yyreduce:
case 77:
#line 476 "parse-gram.y"
{ grammar_current_rule_action_append (gram_last_string,
gram_last_braced_code_loc); }
{
if (current_rule && current_rule->action)
grammar_midrule_action ();
grammar_current_rule_action_append ((yyvsp[(2) - (2)].chars), (yylsp[(2) - (2)]));
}
break;
case 78:
#line 479 "parse-gram.y"
#line 482 "parse-gram.y"
{ grammar_current_rule_prec_set ((yyvsp[(3) - (3)].symbol), (yylsp[(3) - (3)])); }
break;
case 79:
#line 481 "parse-gram.y"
#line 484 "parse-gram.y"
{ grammar_current_rule_dprec_set ((yyvsp[(3) - (3)].integer), (yylsp[(3) - (3)])); }
break;
case 80:
#line 483 "parse-gram.y"
#line 486 "parse-gram.y"
{ grammar_current_rule_merge_set ((yyvsp[(3) - (3)].uniqstr), (yylsp[(3) - (3)])); }
break;
case 81:
#line 496 "parse-gram.y"
#line 499 "parse-gram.y"
{ (yyval.symbol) = symbol_from_uniqstr ((yyvsp[(1) - (1)].uniqstr), (yylsp[(1) - (1)])); }
break;
case 82:
#line 498 "parse-gram.y"
#line 501 "parse-gram.y"
{
(yyval.symbol) = symbol_get (char_name ((yyvsp[(1) - (1)].character)), (yylsp[(1) - (1)]));
symbol_class_set ((yyval.symbol), token_sym, (yylsp[(1) - (1)]), false);
@@ -2207,12 +2210,12 @@ yyreduce:
break;
case 83:
#line 506 "parse-gram.y"
#line 509 "parse-gram.y"
{ (yyval.symbol) = symbol_from_uniqstr ((yyvsp[(1) - (1)].uniqstr), (yylsp[(1) - (1)])); }
break;
case 86:
#line 518 "parse-gram.y"
#line 521 "parse-gram.y"
{
(yyval.symbol) = symbol_get (quotearg_style (c_quoting_style, (yyvsp[(1) - (1)].chars)), (yylsp[(1) - (1)]));
symbol_class_set ((yyval.symbol), token_sym, (yylsp[(1) - (1)]), false);
@@ -2220,12 +2223,12 @@ yyreduce:
break;
case 87:
#line 527 "parse-gram.y"
#line 530 "parse-gram.y"
{ (yyval.chars) = (yyvsp[(1) - (1)].chars); }
break;
case 89:
#line 534 "parse-gram.y"
#line 537 "parse-gram.y"
{
muscle_code_grow ("epilogue", translate_code ((yyvsp[(2) - (2)].chars), (yylsp[(2) - (2)])), (yylsp[(2) - (2)]));
gram_scanner_last_string_free ();
@@ -2234,7 +2237,7 @@ yyreduce:
/* Line 1274 of yacc.c. */
#line 2238 "parse-gram.c"
#line 2241 "parse-gram.c"
default: break;
}
YY_SYMBOL_PRINT ("-> $$ =", yyr1[yyn], &yyval, &yyloc);
@@ -2454,7 +2457,7 @@ yyreturn:
}
#line 540 "parse-gram.y"
#line 543 "parse-gram.y"

7
src/parse-gram.y
View File

@@ -473,8 +473,11 @@ rhs:
| rhs symbol
{ grammar_current_rule_symbol_append ($2, @2); }
| rhs "{...}"
{ grammar_current_rule_action_append (gram_last_string,
gram_last_braced_code_loc); }
{
if (current_rule && current_rule->action)
grammar_midrule_action ();
grammar_current_rule_action_append ($2, @2);
}
| rhs "%prec" symbol
{ grammar_current_rule_prec_set ($3, @3); }
| rhs "%dprec" INT

47
src/scan-code.l
View File

@@ -45,18 +45,16 @@
/* The current calling start condition: SC_RULE_ACTION or
SC_SYMBOL_ACTION. */
# define YY_DECL const char *code_lex (int sc_context)
# define YY_DECL const char *code_lex (int sc_context, symbol_list *rule)
YY_DECL;
#define YY_USER_ACTION location_compute (loc, &loc->end, yytext, yyleng);
static void handle_action_dollar (char *cp, location dollar_loc);
static void handle_action_at (char *cp, location at_loc);
static void handle_action_dollar (symbol_list *rule, char *cp,
location dollar_loc);
static void handle_action_at (symbol_list *rule, char *cp, location at_loc);
static location the_location;
static location *loc = &the_location;
/* The rule being processed. */
symbol_list *current_rule;
%}
/* C and C++ comments in code. */
%x SC_COMMENT SC_LINE_COMMENT
@@ -153,8 +151,8 @@ splice (\\[ \f\t\v]*\n)*
<SC_RULE_ACTION>
{
"$"("<"{tag}">")?(-?[0-9]+|"$") handle_action_dollar (yytext, *loc);
"@"(-?[0-9]+|"$") handle_action_at (yytext, *loc);
"$"("<"{tag}">")?(-?[0-9]+|"$") handle_action_dollar (rule, yytext, *loc);
"@"(-?[0-9]+|"$") handle_action_at (rule, yytext, *loc);
"$" {
warn_at (*loc, _("stray `$'"));
@@ -238,11 +236,11 @@ int max_left_semantic_context = 0;
`------------------------------------------------------------------*/
static void
handle_action_dollar (char *text, location dollar_loc)
handle_action_dollar (symbol_list *rule, char *text, location dollar_loc)
{
const char *type_name = NULL;
char *cp = text + 1;
int rule_length = symbol_list_length (current_rule->next);
int rule_length = symbol_list_length (rule->next);
/* Get the type name if explicit. */
if (*cp == '<')
@@ -257,15 +255,15 @@ handle_action_dollar (char *text, location dollar_loc)
if (*cp == '$')
{
if (!type_name)
type_name = symbol_list_n_type_name_get (current_rule, dollar_loc, 0);
type_name = symbol_list_n_type_name_get (rule, dollar_loc, 0);
if (!type_name && typed)
complain_at (dollar_loc, _("$$ of `%s' has no declared type"),
current_rule->sym->tag);
rule->sym->tag);
if (!type_name)
type_name = "";
obstack_fgrow1 (&obstack_for_string,
"]b4_lhs_value([%s])[", type_name);
current_rule->used = true;
rule->used = true;
}
else
{
@@ -279,16 +277,16 @@ handle_action_dollar (char *text, location dollar_loc)
max_left_semantic_context = 1-n;
if (!type_name && n > 0)
type_name =
symbol_list_n_type_name_get (current_rule, dollar_loc, n);
symbol_list_n_type_name_get (rule, dollar_loc, n);
if (!type_name && typed)
complain_at (dollar_loc, _("$%d of `%s' has no declared type"),
n, current_rule->sym->tag);
n, rule->sym->tag);
if (!type_name)
type_name = "";
obstack_fgrow3 (&obstack_for_string,
"]b4_rhs_value(%d, %d, [%s])[",
rule_length, n, type_name);
symbol_list_n_used_set (current_rule, n, true);
symbol_list_n_used_set (rule, n, true);
}
else
complain_at (dollar_loc, _("integer out of range: %s"), quote (text));
@@ -302,10 +300,10 @@ handle_action_dollar (char *text, location dollar_loc)
`------------------------------------------------------*/
static void
handle_action_at (char *text, location at_loc)
handle_action_at (symbol_list *rule, char *text, location at_loc)
{
char *cp = text + 1;
int rule_length = symbol_list_length (current_rule->next);
int rule_length = symbol_list_length (rule->next);
locations_flag = true;
if (*cp == '$')
@@ -337,7 +335,7 @@ handle_action_at (char *text, location at_loc)
INITIAL), the processing is different. */
static const char *
translate_action (int sc_context, const char *a, location l)
translate_action (int sc_context, symbol_list *rule, const char *a, location l)
{
const char *res;
static bool initialized = false;
@@ -352,29 +350,28 @@ translate_action (int sc_context, const char *a, location l)
loc->start = loc->end = l.start;
yy_switch_to_buffer (yy_scan_string (a));
res = code_lex (sc_context);
res = code_lex (sc_context, rule);
yy_delete_buffer (YY_CURRENT_BUFFER);
return res;
}
const char *
translate_rule_action (symbol_list *r, const char *a, location l)
translate_rule_action (symbol_list *rule, const char *a, location l)
{
current_rule = r;
return translate_action (SC_RULE_ACTION, a, l);
return translate_action (SC_RULE_ACTION, rule, a, l);
}
const char *
translate_symbol_action (const char *a, location l)
{
return translate_action (SC_SYMBOL_ACTION, a, l);
return translate_action (SC_SYMBOL_ACTION, NULL, a, l);
}
const char *
translate_code (const char *a, location l)
{
return translate_action (INITIAL, a, l);
return translate_action (INITIAL, NULL, a, l);
}
/*-----------------------------------------------.

2
src/scan-gram.l
View File

@@ -243,8 +243,6 @@ splice (\\[ \f\t\v]*\n)*
/* Code in between braces. */
"{" {
if (current_rule && current_rule->action)
grammar_midrule_action ();
STRING_GROW;
braces_level = 0;
code_start = loc->start;

76
tests/regression.at
View File

@@ -1004,3 +1004,79 @@ AT_CLEANUP
AT_CHECK_EXPECT2()
AT_CHECK_EXPECT2([%glr-parser])
AT_CHECK_EXPECT2([%skeleton "lalr1.cc"])
## --------------------------------------------- ##
## Braced code in declaration in rules section. ##
## --------------------------------------------- ##
AT_SETUP([Braced code in declaration in rules section])
# Bison once mistook braced code in a declaration in the rules section to be a
# rule action.
AT_DATA_GRAMMAR([input.y],
[[%{
#include <stdio.h>
void yyerror (char const *msg);
int yylex (void);
%}
%error-verbose
%%
start:
{
printf ("Bison would once convert this action to a midrule because of the"
" subsequent braced code.\n");
}
;
%destructor { fprintf (stderr, "DESTRUCTOR\n"); } 'a';
%printer { fprintf (yyoutput, "PRINTER"); } 'a';
%%
void
yyerror (char const *msg)
{
fprintf (stderr, "%s\n", msg);
}
int
yylex (void)
{
return 'a';
}
int
main (void)
{
yydebug = 1;
return !yyparse ();
}
]])
AT_CHECK([bison -t -o input.c input.y])
AT_COMPILE([input])
AT_PARSER_CHECK([./input], 0,
[[Bison would once convert this action to a midrule because of the subsequent braced code.
]],
[[Starting parse
Entering state 0
Reducing stack by rule 1 (line 22):
-> $$ = nterm start ()
Stack now 0
Entering state 1
Reading a token: Next token is token 'a' (PRINTER)
syntax error, unexpected 'a', expecting $end
Error: popping nterm start ()
Stack now 0
Cleanup: discarding lookahead token 'a' (PRINTER)
DESTRUCTOR
Stack now 0
]])
AT_CLEANUP