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Remove the so called hairy (semantic) parsers.

Browse Source 
* src/system.h (EXT_GUARD_C, EXT_STYPE_H): Remove.
* src/gram.h, src/gram.c (semantic_parser): Remove.
(rule_t): Remove the guard and guard_line members.
* src/lex.h (token_t): remove tok_guard.
* src/options.c (option_table): Remove %guard and %semantic_parser
support.
* src/output.c, src/output.h (guards_output): Remove.
(prepare): Adjust.
(token_definitions_output): Don't output the `T'
tokens (???).
(output_skeleton): Don't output the guards.
* src/files.c, src/files.c (attrsfile): Remove.
* src/reader.c (symbol_list): Remove the guard and guard_line
members.
Adjust dependencies.
(parse_guard): Remove.
* data/bison.hairy: Remove.
* doc/bison.texinfo (Environment Variables): Remove occurrences of
BISON_HAIRY.
This commit is contained in:
Akim Demaille
2002-05-02 15:06:46 +00:00
parent 64bd62a1be
commit fdbcd8e289
21 changed files with 49 additions and 512 deletions
Download Patch File Download Diff File Expand all files Collapse all files

24
ChangeLog
View File

@@ -1,3 +1,27 @@
2002-05-02 Akim Demaille <akim@epita.fr>
Remove the so called hairy (semantic) parsers.
* src/system.h (EXT_GUARD_C, EXT_STYPE_H): Remove.
* src/gram.h, src/gram.c (semantic_parser): Remove.
(rule_t): Remove the guard and guard_line members.
* src/lex.h (token_t): remove tok_guard.
* src/options.c (option_table): Remove %guard and %semantic_parser
support.
* src/output.c, src/output.h (guards_output): Remove.
(prepare): Adjust.
(token_definitions_output): Don't output the `T'
tokens (???).
(output_skeleton): Don't output the guards.
* src/files.c, src/files.c (attrsfile): Remove.
* src/reader.c (symbol_list): Remove the guard and guard_line
members.
Adjust dependencies.
(parse_guard): Remove.
* data/bison.hairy: Remove.
* doc/bison.texinfo (Environment Variables): Remove occurrences of
BISON_HAIRY.
2002-05-02 Akim Demaille <akim@epita.fr>
* src/reader.c (copy_at, copy_dollarm parse_braces, parse_action)

4
NEWS
View File

@@ -55,6 +55,10 @@ Changes in version 1.49b:
%token YYEOF 0
or
%token YYEOF 0 "end of file"
* Semantic parser
This old option, which has been broken for ages, is removed.
Changes in version 1.35, 2002-03-25:

1
TODO
View File

@@ -214,7 +214,6 @@ Show reductions. []
** %no-lines [ok]
** %no-parser []
** %pure-parser []
** %semantic-parser []
** %token-table []
** Options which could use parse_dquoted_param ().
Maybe transfered in lex.c.

4
data/Makefile.am
View File

@@ -1,4 +1,4 @@
## Copyright 2002 Free Software Foundation, Inc.
## Copyright (C) 2002 Free Software Foundation, Inc.
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
@@ -15,7 +15,7 @@
## Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
## 02111-1307 USA
dist_pkgdata_DATA = bison.simple bison.hairy bison.c++
dist_pkgdata_DATA = bison.simple bison.c++
m4sugardir = $(pkgdatadir)/m4sugar
dist_m4sugar_DATA = m4sugar/m4sugar.m4 m4sugar/version.m4

336
data/bison.hairy
View File

@@ -1,336 +0,0 @@
%%{section} %%{output-prefix} %%{output-infix} %%".c"
/* -*- C -*- */
/* YYERROR and YYCOST are set by guards. If yyerror is set to a
nonzero value by a guard, the reduction with which the guard is
associated is not performed, and the error recovery mechanism is
invoked. Yycost indicates the cost of performing the reduction
given the attributes of the symbols. */
static int yyerror;
static int yycost;
/* YYMAXDEPTH indicates the size of the parser's state and value
stacks. */
#ifndef YYMAXDEPTH
# define YYMAXDEPTH 500
#endif
/* YYMAXRULES must be at least as large as the number of rules that
could be placed in the rule queue. That number could be determined
from the grammar and the size of the stack, but, as yet, it is not.
*/
#ifndef YYMAXRULES
# define YYMAXRULES 100
#endif
#ifndef YYMAXBACKUP
# define YYMAXBACKUP 100
#endif
/* The state stack. */
static short yyss[YYMAXDEPTH];
/* The semantic value stack. */
static YYSTYPE yyvs[YYMAXDEPTH];
/* The location stack. */
static YYLTYPE yyls[YYMAXDEPTH];
/* The rule queue. */
static short yyrq[YYMAXRULES];
/* The lookahead symbol. */
static int yychar;
/* the semantic value of the lookahead symbol. */
static YYSTYPE yylval;
/* the semantic value for the state at the top of the state stack. */
static YYSTYPE yytval;
/* the variable used to return semantic values from the action
routines. */
static YYSTYPE yyval;
/* location data for the lookahead symbol. */
static YYLTYPE yylloc;
/* location data for the state at the top of the state stack. */
static YYLTYPE yytloc;
static int yynunlexed;
static short yyunchar[YYMAXBACKUP];
static YYSTYPE yyunval[YYMAXBACKUP];
static YYLTYPE yyunloc[YYMAXBACKUP];
/* a pointer to the top of the state stack; only set during error
recovery. */
static short *yygssp;
/* a pointer to the top of the value stack; only set during error
recovery. */
static YYSTYPE *yygvsp;
/* a pointer to the top of the location stack; only set during error
recovery. */
static YYLTYPE *yyglsp;
/*--------------------------------------------------------------------.
| Yyget is an interface between the parser and the lexical analyzer. |
| It is costly to provide such an interface, but it avoids requiring |
| the lexical analyzer to be able to back up the scan. |
`--------------------------------------------------------------------*/
static inline void
yyget (void)
{
if (yynunlexed > 0)
{
yynunlexed--;
yychar = yyunchar[yynunlexed];
yylval = yyunval[yynunlexed];
yylloc = yyunloc[yynunlexed];
}
else if (yychar <= 0)
yychar = 0;
else
{
yychar = yylex ();
if (yychar < 0)
yychar = 0;
else
yychar = YYTRANSLATE (yychar);
}
}
static inline void
yyunlex (int chr, YYSTYPE val, YYLTYPE loc)
{
yyunchar[yynunlexed] = chr;
yyunval[yynunlexed] = val;
yyunloc[yynunlexed] = loc;
yynunlexed++;
}
static inline void
yyrestore (short *first, short *last)
{
short *ssp;
short *rp;
int symbol;
int state;
int tvalsaved;
ssp = yygssp;
yyunlex (yychar, yylval, yylloc);
tvalsaved = 0;
while (first != last)
{
symbol = yystos[*ssp];
if (symbol < YYNTBASE)
{
yyunlex (symbol, yytval, yytloc);
tvalsaved = 1;
ssp--;
}
ssp--;
if (first == yyrq)
first = yyrq + YYMAXRULES;
first--;
for (rp = yyrhs + yyprhs[*first]; symbol = *rp; rp++)
{
if (symbol < YYNTBASE)
state = yytable[yypact[*ssp] + symbol];
else
{
state = yypgoto[symbol - YYNTBASE] + *ssp;
if (state >= 0 && state <= YYLAST && yycheck[state] == *ssp)
state = yytable[state];
else
state = yydefgoto[symbol - YYNTBASE];
}
*++ssp = state;
}
}
if (!tvalsaved && ssp > yyss)
{
yyunlex (yystos[*ssp], yytval, yytloc);
ssp--;
}
yygssp = ssp;
}
int
yyparse (void)
{
int yystate;
int yyn;
short *yyssp;
short *yyrq0;
short *yyptr;
YYSTYPE *yyvsp;
int yylen;
YYLTYPE *yylsp;
short *yyrq1;
short *yyrq2;
yystate = 0;
yyssp = yyss - 1;
yyvsp = yyvs - 1;
yylsp = yyls - 1;
yyrq0 = yyrq;
yyrq1 = yyrq0;
yyrq2 = yyrq0;
yychar = yylex ();
if (yychar < 0)
yychar = 0;
else
yychar = YYTRANSLATE (yychar);
yynewstate:
if (yyssp >= yyss + YYMAXDEPTH - 1)
{
yyabort ("Parser Stack Overflow");
YYABORT;
}
*++yyssp = yystate;
yyresume:
yyn = yypact[yystate];
if (yyn == YYFLAG)
goto yydefault;
yyn += yychar;
if (yyn < 0 || yyn > YYLAST || yycheck[yyn] != yychar)
goto yydefault;
yyn = yytable[yyn];
if (yyn < 0)
{
yyn = -yyn;
goto yyreduce;
}
else if (yyn == 0)
goto yyerrlab;
yystate = yyn;
yyptr = yyrq2;
while (yyptr != yyrq1)
{
yyn = *yyptr++;
yylen = yyr2[yyn];
yyvsp -= yylen;
yylsp -= yylen;
yyguard (yyn, yyvsp, yylsp);
if (yyerror)
goto yysemerr;
yyaction (yyn, yyvsp, yylsp);
*++yyvsp = yyval;
yylsp++;
if (yylen == 0)
{
yylsp->first_line = yytloc.first_line;
yylsp->first_column = yytloc.first_column;
yylsp->last_line = (yylsp - 1)->last_line;
yylsp->last_column = (yylsp - 1)->last_column;
yylsp->text = 0;
}
else
{
yylsp->last_line = (yylsp + yylen - 1)->last_line;
yylsp->last_column = (yylsp + yylen - 1)->last_column;
}
if (yyptr == yyrq + YYMAXRULES)
yyptr = yyrq;
}
if (yystate == YYFINAL)
YYACCEPT;
yyrq2 = yyptr;
yyrq1 = yyrq0;
*++yyvsp = yytval;
*++yylsp = yytloc;
yytval = yylval;
yytloc = yylloc;
yyget ();
goto yynewstate;
yydefault:
yyn = yydefact[yystate];
if (yyn == 0)
goto yyerrlab;
yyreduce:
*yyrq0++ = yyn;
if (yyrq0 == yyrq + YYMAXRULES)
yyrq0 = yyrq;
if (yyrq0 == yyrq2)
{
yyabort ("Parser Rule Queue Overflow");
YYABORT;
}
yyssp -= yyr2[yyn];
yyn = yyr1[yyn];
yystate = yypgoto[yyn - YYNTBASE] + *yyssp;
if (yystate >= 0 && yystate <= YYLAST && yycheck[yystate] == *yyssp)
yystate = yytable[yystate];
else
yystate = yydefgoto[yyn - YYNTBASE];
goto yynewstate;
yysemerr:
*--yyptr = yyn;
yyrq2 = yyptr;
yyvsp += yyr2[yyn];
yyerrlab:
yygssp = yyssp;
yygvsp = yyvsp;
yyglsp = yylsp;
yyrestore (yyrq0, yyrq2);
yyrecover ();
yystate = *yygssp;
yyssp = yygssp;
yyvsp = yygvsp;
yyrq0 = yyrq;
yyrq1 = yyrq0;
yyrq2 = yyrq0;
goto yyresume;
}
%%{actions}

4
data/bison.simple
View File

@@ -116,8 +116,8 @@ m4_divert(0)dnl
/* This is the parser code that is written into each bison parser when
the %semantic_parser declaration is not specified in the grammar.
It was written by Richard Stallman by simplifying the hairy parser
used when %semantic_parser is specified. */
It was written by Richard Stallman by simplifying the original so
called ``semantic'' parser. */
/* All symbols defined below should begin with yy or YY, to avoid
infringing on user name space. This should be done even for local

8
doc/bison.texinfo
View File

@@ -5233,7 +5233,6 @@ the output graph filename.
@node Environment Variables
@section Environment Variables
@cindex environment variables
@cindex BISON_HAIRY
@cindex BISON_SIMPLE
Here is a list of environment variables which affect the way Bison
@@ -5241,18 +5240,11 @@ runs.
@table @samp
@item BISON_SIMPLE
@itemx BISON_HAIRY
Much of the parser generated by Bison is copied verbatim from a file
called @file{bison.simple}. If Bison cannot find that file, or if you
would like to direct Bison to use a different copy, setting the
environment variable @code{BISON_SIMPLE} to the path of the file will
cause Bison to use that copy instead.
When the @samp{%semantic-parser} declaration is used, Bison copies from
a file called @file{bison.hairy} instead. The location of this file can
also be specified or overridden in a similar fashion, with the
@code{BISON_HAIRY} environment variable.
@end table
@node Option Cross Key

3
src/files.c
View File

@@ -53,7 +53,6 @@ char *spec_defines_file = NULL; /* for --defines. */
char *parser_file_name = NULL;
char *infile = NULL;
char *attrsfile = NULL;
static char *full_base_name = NULL;
@@ -436,6 +435,4 @@ compute_output_file_names (void)
spec_graph_file = stringappend (short_base_name, ".vcg");
spec_verbose_file = stringappend (short_base_name, EXT_OUTPUT);
attrsfile = stringappend (short_base_name, EXT_STYPE_H);
}

1
src/files.h
View File

@@ -57,7 +57,6 @@ extern struct obstack post_prologue_obstack;
extern struct obstack output_obstack;
extern char *infile;
extern char *attrsfile;
void compute_output_file_names PARAMS((void));

2
src/gram.c
View File

@@ -45,8 +45,6 @@ token_number_t start_symbol = 0;
int max_user_token_number = 256;
int semantic_parser = 0;
int pure_parser = 0;

10
src/gram.h
View File

@@ -47,7 +47,7 @@
Therefore 0 cannot be used, since it would be both the rule number
0, and the token EOF).
Actions and guards are accessed via the rule number.
Actions are accessed via the rule number.
The rules themselves are described by several arrays: amongst which
RITEM, and RULES.
@@ -150,9 +150,6 @@ typedef struct rule_s
const char *action;
int action_line;
const char *guard;
int guard_line;
} rule_t;
extern struct rule_s *rules;
@@ -166,11 +163,6 @@ extern symbol_t **symbols;
extern token_number_t *token_translations;
extern int max_user_token_number;
/* SEMANTIC_PARSER is nonzero if the input file says to use the hairy
parser that provides for semantic error recovery. If it is zero,
the yacc-compatible simplified parser is used. */
extern int semantic_parser;
/* PURE_PARSER is nonzero if should generate a parser that is all pure
and reentrant. */

1
src/lex.h
View File

@@ -36,7 +36,6 @@ typedef enum token_e
tok_percent_left_curly,
tok_token,
tok_nterm,
tok_guard,
tok_type,
tok_union,
tok_start,

2
src/options.c
View File

@@ -83,7 +83,6 @@ const struct option_table_struct option_table[] =
DRTV ("term", no, NULL, tok_token)
DRTV ("nterm", no, NULL, tok_nterm)
DRTV ("type", no, NULL, tok_type)
DRTV ("guard", no, NULL, tok_guard)
DRTV ("union", no, NULL, tok_union)
DRTV ("expect", no, NULL, tok_expect)
DRTV ("thong", no, NULL, tok_thong)
@@ -104,7 +103,6 @@ const struct option_table_struct option_table[] =
BOTH ("name-prefix", required, &spec_name_prefix, tok_stropt, 'p')
DRTV ("define", no, NULL, tok_define)
DRTV ("semantic-parser",no, &semantic_parser, tok_intopt)
DRTV ("pure-parser", no, &pure_parser, tok_intopt)
/*

39
src/output.c
View File

@@ -568,30 +568,6 @@ actions_output (FILE *out)
}
/*----------------------------.
| Output the guards to OOUT. |
`----------------------------*/
void
guards_output (FILE *out)
{
int rule;
for (rule = 1; rule < nrules + 1; ++rule)
if (rules[rule].guard)
{
fprintf (out, " case %d:\n", rule);
if (!no_lines_flag)
fprintf (out, muscle_find ("linef"),
rules[rule].guard_line,
quotearg_style (c_quoting_style,
muscle_find ("filename")));
fprintf (out, "{ %s; }\n break;\n\n",
rules[rule].guard);
}
}
/*---------------------------------------.
| Output the tokens definition to OOUT. |
`---------------------------------------*/
@@ -629,10 +605,6 @@ token_definitions_output (FILE *out)
fprintf (out, "%s [[[%s]], [%d]]",
first ? "" : ",\n", symbol->tag, number);
if (semantic_parser)
/* FIXME: This is probably wrong, and should be just as
above. --akim. */
fprintf (out, "# define T%s\t%d\n", symbol->tag, symbol->number);
first = 0;
}
}
@@ -1020,10 +992,6 @@ output_skeleton (void)
actions_output (out);
fputs ("]])\n\n", out);
fputs ("m4_define([b4_guards], \n[[", out);
guards_output (out);
fputs ("]])\n\n", out);
fputs ("m4_define([b4_tokens], \n[", out);
token_definitions_output (out);
fputs ("])\n\n", out);
@@ -1099,12 +1067,7 @@ prepare (void)
/* Find the right skeleton file. */
if (!skeleton)
{
if (semantic_parser)
skeleton = "bison.hairy";
else
skeleton = "bison.simple";
}
skeleton = "bison.simple";
/* Parse the skeleton file and output the needed parsers. */
muscle_insert ("skeleton", skeleton);

1
src/output.h
View File

@@ -27,7 +27,6 @@ extern int error_verbose;
void output PARAMS ((void));
void actions_output PARAMS ((FILE *out));
void guards_output PARAMS ((FILE *out));
void token_definitions_output PARAMS ((FILE *out));
extern struct obstack muscle_obstack;

51
src/reader.c
View File

@@ -45,9 +45,6 @@ typedef struct symbol_list
const char *action;
int action_line;
/* The guard is attached to the LHS of a rule. */
const char *guard;
int guard_line;
symbol_t *ruleprec;
} symbol_list;
@@ -80,8 +77,6 @@ symbol_list_new (symbol_t *sym)
res->line = lineno;
res->action = NULL;
res->action_line = 0;
res->guard = NULL;
res->guard_line = 0;
res->ruleprec = NULL;
return res;
}
@@ -1273,9 +1268,7 @@ read_declarations (void)
| values in the current rule so far, which says where to find `$0' |
| with respect to the top of the stack. |
| |
| This routine is used both for actions and guards. Only |
| ACTION_OBSTACK is used, but this is fine, since we use only |
| pointers to relevant portions inside this obstack. |
| This routine is used for actions. |
`------------------------------------------------------------------*/
static void
@@ -1341,18 +1334,6 @@ parse_action (symbol_list *rule, int rule_length)
rule->action = obstack_finish (&action_obstack);
}
static void
parse_guard (symbol_list *rule, int rule_length)
{
token_t t = lex ();
if (t != tok_left_curly)
complain (_("invalid %s declaration"), "%guard");
rule->guard_line = lineno;
parse_braces (rule, rule_length);
rule->guard = obstack_finish (&action_obstack);
}
/*-------------------------------------------------------------------.
@@ -1384,8 +1365,8 @@ gensym (void)
| null pointer instead of a symbol to terminate the rule. The next |
| symbol is the lhs of the following rule. |
| |
| All guards and actions are copied out to the appropriate files, |
| labelled by the rule number they apply to. |
| All actions are copied out, labelled by the rule number they apply |
| to. |
| |
| Bison used to allow some %directives in the rules sections, but |
| this is no longer consider appropriate: (i) the documented grammar |
@@ -1582,15 +1563,6 @@ readgram (void)
t = lex ();
}
if (t == tok_guard)
{
if (!semantic_parser)
complain (_("%%guard present but %%semantic_parser not specified"));
parse_guard (crule, rulelength);
t = lex ();
}
if (t == tok_left_curly)
{
/* This case never occurs -wjh */
@@ -1791,8 +1763,6 @@ packgram (void)
rules[ruleno].useful = TRUE;
rules[ruleno].action = p->action;
rules[ruleno].action_line = p->action_line;
rules[ruleno].guard = p->guard;
rules[ruleno].guard_line = p->guard_line;
p = p->next;
while (p && p->sym)
@@ -1829,13 +1799,12 @@ packgram (void)
ritem_print (stderr);
}
/*-------------------------------------------------------------------.
| Read in the grammar specification and record it in the format |
| described in gram.h. All guards are copied into the GUARD_OBSTACK |
| and all actions into ACTION_OBSTACK, in each case forming the body |
| of a C function (YYGUARD or YYACTION) which contains a switch |
| statement to decide which guard or action to execute. |
`-------------------------------------------------------------------*/
/*------------------------------------------------------------------.
| Read in the grammar specification and record it in the format |
| described in gram.h. All actions are copied into ACTION_OBSTACK, |
| in each case forming the body of a C function (YYACTION) which |
| contains a switch statement to decide which action to execute. |
`------------------------------------------------------------------*/
void
reader (void)
@@ -1889,7 +1858,7 @@ reader (void)
}
/* Read in the grammar, build grammar in list form. Write out
guards and actions. */
actions. */
readgram ();
/* Some C code is given at the end of the grammar file. */
read_additionnal_code ();

5
src/reader.h
View File

@@ -24,10 +24,7 @@
#include "symtab.h"
/* Read in the grammar specification and record it in the format
described in gram.h. All guards are copied into the FGUARD file
and all actions into FACTION, in each case forming the body of a C
function (YYGUARD or YYACTION) which contains a switch statement to
decide which guard or action to execute. */
described in gram.h. */
void reader PARAMS ((void));

6
src/system.h
View File

@@ -238,21 +238,15 @@ do { \
/* VMS. */
# define EXT_TAB "_tab"
# define EXT_OUTPUT ".output"
# define EXT_STYPE_H "_stype"
# define EXT_GUARD_C "_guard"
#else /* ! VMS */
# ifdef MSDOS
/* MS DOS. */
# define EXT_TAB "_tab"
# define EXT_OUTPUT ".out"
# define EXT_STYPE_H ".sth"
# define EXT_GUARD_C ".guc"
# else /* ! MSDOS */
/* Standard. */
# define EXT_TAB ".tab"
# define EXT_OUTPUT ".output"
# define EXT_STYPE_H ".stype"
# define EXT_GUARD_C ".guard"
# endif /* ! MSDOS */
#endif /* ! VMS */

5
tests/Makefile.am
View File

@@ -1,7 +1,7 @@
## Process this file with automake to create Makefile.in.
## Makefile for Bison testsuite.
## Copyright 2000, 2001, 2002 Free Software Foundation, Inc.
## Copyright (C) 2000, 2001, 2002 Free Software Foundation, Inc.
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
@@ -49,8 +49,7 @@ TESTSUITE_AT = \
output.at sets.at reduce.at \
synclines.at headers.at actions.at conflicts.at \
calc.at \
torture.at existing.at regression.at \
semantic.at
torture.at existing.at regression.at
TESTSUITE = $(srcdir)/testsuite

47
tests/semantic.at
View File

@@ -1,47 +0,0 @@
# Bison Semantic Parsers. -*- Autotest -*-
# Copyright 2001 Free Software Foundation, Inc.
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2, or (at your option)
# any later version.
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
# 02111-1307, USA.
AT_BANNER([[Semantic Parsers.]])
# Well, nothing, or almost, is known about semantic parsers. For the
# time being, just make sure we still parse them properly.
## ---------------- ##
## Parsing Guards. ##
## ---------------- ##
AT_SETUP([Parsing Guards])
AT_DATA([input.y],
[[%semantic-parser
%union {
int ival;
}
%token <ival> INT
%type <ival> exp
%%
exp: exp '+' exp { $$ = $1 + $3 }
| exp '/' exp %guard { if ($3 == 0) yyerror = 1 } { $$ = $1 / $3 }
| INT;
%%
]])
AT_CHECK([bison -v input.y -o input.c], 0, ignore, ignore)
AT_CLEANUP

3
tests/testsuite.at
View File

@@ -61,6 +61,3 @@ m4_include([existing.at])
# Some old bugs.
m4_include([regression.at])
# Exercising bison.hairy, before it gets really removed...
m4_include([semantic.at])