/* Bison Grammar Parser -*- C -*-
Copyright (C) 2002 Free Software Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
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 of the License, 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
*/
%debug
%defines
%locations
%pure-parser
// %error-verbose
%defines
%name-prefix="gram_"
%{
#include "system.h"
#include "complain.h"
#include "muscle_tab.h"
#include "files.h"
#include "getargs.h"
#include "output.h"
#include "symlist.h"
#include "gram.h"
#include "reader.h"
#include "conflicts.h"
/* Produce verbose parse errors. */
#define YYERROR_VERBOSE 1
#define YYLLOC_DEFAULT(Current, Rhs, N) \
do { \
if (N) \
{ \
Current.first_column = Rhs[1].first_column; \
Current.first_line = Rhs[1].first_line; \
Current.last_column = Rhs[N].last_column; \
Current.last_line = Rhs[N].last_line; \
} \
else \
{ \
Current = Rhs[0]; \
} \
} while (0)
/* Pass the control structure to YYPARSE and YYLEX. */
#define YYPARSE_PARAM gram_control
#define YYLEX_PARAM gram_control
/* YYPARSE receives GRAM_CONTROL as a void *. Provide a
correctly typed access to it. */
#define yycontrol ((gram_control_t *) gram_control)
/* Request detailed parse error messages, and pass them to GRAM_ERROR.
FIXME: depends on the undocumented availability of YYLLOC.t */
#undef yyerror
#define yyerror(Msg) \
gram_error (&yylloc, Msg)
#define YYPRINT(File, Type, Value) \
yyprint (File, Type, &Value)
static void yyprint (FILE *file, int type, const yystype *value);
symbol_class current_class = unknown_sym;
char *current_type = 0;
symbol_t *current_lhs;
location_t current_lhs_location;
assoc_t current_assoc;
int current_prec = 0;
braced_code_t current_braced_code = action_braced_code;
%}
/* Only NUMBERS have a value. */
%union
{
symbol_t *symbol;
symbol_list_t *list;
int integer;
char *string;
assoc_t assoc;
};
/* Define the tokens together with their human representation. */
%token GRAM_EOF 0 "end of file"
%token STRING "string"
%token CHARACTER "character"
%token INT "integer"
%token PERCENT_TOKEN "%token"
%token PERCENT_NTERM "%nterm"
%token PERCENT_TYPE "%type"
%token PERCENT_DESTRUCTOR "%destructor"
%token PERCENT_PRINTER "%printer"
%token PERCENT_UNION "%union"
%token PERCENT_LEFT "%left"
%token PERCENT_RIGHT "%right"
%token PERCENT_NONASSOC "%nonassoc"
%token PERCENT_EXPECT "%expect"
%token PERCENT_START "%start"
%token PERCENT_PREC "%prec"
%token PERCENT_DPREC "%dprec"
%token PERCENT_MERGE "%merge"
%token PERCENT_VERBOSE "%verbose"
%token PERCENT_ERROR_VERBOSE "%error-verbose"
%token PERCENT_OUTPUT "%output"
%token PERCENT_FILE_PREFIX "%file-prefix"
%token PERCENT_NAME_PREFIX "%name-prefix"
%token PERCENT_DEFINE "%define"
%token PERCENT_PURE_PARSER "%pure-parser"
%token PERCENT_GLR_PARSER "%glr-parser"
%token PERCENT_DEFINES "%defines"
%token PERCENT_YACC "%yacc"
%token PERCENT_DEBUG "%debug"
%token PERCENT_LOCATIONS "%locations"
%token PERCENT_NO_LINES "%no-lines"
%token PERCENT_SKELETON "%skeleton"
%token PERCENT_TOKEN_TABLE "%token-table"
%token TYPE "type"
%token EQUAL "="
%token SEMICOLON ";"
%token COLON ":"
%token PIPE "|"
%token ID "identifier"
%token PERCENT_PERCENT "%%"
%token PROLOGUE "%{...%}"
%token EPILOGUE "epilogue"
%token BRACED_CODE "{...}"
%type <string> CHARACTER TYPE STRING string_content
BRACED_CODE PROLOGUE EPILOGUE epilogue.opt action
%type <integer> INT
%type <symbol> ID symbol string_as_id
%type <assoc> precedence_declarator
%type <list> symbols.1
%%
input:
declarations "%%" grammar epilogue.opt
{
yycontrol->errcode = 0;
epilogue_set ($4, @4);
}
;
/*------------------------------------.
| Declarations: before the first %%. |
`------------------------------------*/
declarations:
/* Nothing */
| declarations declaration semi_colon.opt
;
declaration:
grammar_declaration
| PROLOGUE { prologue_augment ($1, @1); }
| "%debug" { debug_flag = 1; }
| "%define" string_content string_content { muscle_insert ($2, $3); }
| "%defines" { defines_flag = 1; }
| "%error-verbose" { error_verbose = 1; }
| "%expect" INT { expected_conflicts = $2; }
| "%file-prefix" "=" string_content { spec_file_prefix = $3; }
| "%locations" { locations_flag = 1; }
| "%name-prefix" "=" string_content { spec_name_prefix = $3; }
| "%no-lines" { no_lines_flag = 1; }
| "%output" "=" string_content { spec_outfile = $3; }
| "%pure-parser" { pure_parser = 1; }
| "%glr-parser" { glr_parser = 1; }
| "%skeleton" string_content { skeleton = $2; }
| "%token-table" { token_table_flag = 1; }
| "%verbose" { report_flag = 1; }
| "%yacc" { yacc_flag = 1; }
;
grammar_declaration:
precedence_declaration
| symbol_declaration
| "%start" symbol
{
grammar_start_symbol_set ($2, @2);
}
| "%union" BRACED_CODE
{
typed = 1;
MUSCLE_INSERT_INT ("stype_line", @2.first_line);
muscle_insert ("stype", $2);
}
| "%destructor"
{ current_braced_code = destructor_braced_code; }
BRACED_CODE symbols.1
{
symbol_list_t *list;
for (list = $4; list; list = list->next)
symbol_destructor_set (list->sym, $3, @3);
symbol_list_free ($4);
current_braced_code = action_braced_code;
}
| "%printer"
{ current_braced_code = printer_braced_code; }
BRACED_CODE symbols.1
{
symbol_list_t *list;
for (list = $4; list; list = list->next)
symbol_printer_set (list->sym, $3, list->location);
symbol_list_free ($4);
current_braced_code = action_braced_code;
}
;
symbol_declaration:
"%nterm" { current_class = nterm_sym; } symbol_defs.1
{
current_class = unknown_sym;
current_type = NULL;
}
| "%token" { current_class = token_sym; } symbol_defs.1
{
current_class = unknown_sym;
current_type = NULL;
}
| "%type" TYPE symbols.1
{
symbol_list_t *list;
for (list = $3; list; list = list->next)
symbol_type_set (list->sym, $2, @2);
symbol_list_free ($3);
}
;
precedence_declaration:
precedence_declarator type.opt symbols.1
{
symbol_list_t *list;
++current_prec;
for (list = $3; list; list = list->next)
{
symbol_type_set (list->sym, current_type, @2);
symbol_precedence_set (list->sym, current_prec, $1, @1);
}
symbol_list_free ($3);
current_type = NULL;
}
;
precedence_declarator:
"%left" { $$ = left_assoc; }
| "%right" { $$ = right_assoc; }
| "%nonassoc" { $$ = non_assoc; }
;
type.opt:
/* Nothing. */ { current_type = NULL;}
| TYPE { current_type = $1; }
;
/* One or more nonterminals to be %typed. */
symbols.1:
symbol { $$ = symbol_list_new ($1, @1); }
| symbols.1 symbol { $$ = symbol_list_prepend ($1, $2, @2); }
;
/* One token definition. */
symbol_def:
TYPE
{
current_type = $1;
}
| ID
{
symbol_class_set ($1, current_class, @1);
symbol_type_set ($1, current_type, @1);
}
| ID INT
{
symbol_class_set ($1, current_class, @1);
symbol_type_set ($1, current_type, @1);
symbol_user_token_number_set ($1, $2, @2);
}
| ID string_as_id
{
symbol_class_set ($1, current_class, @1);
symbol_type_set ($1, current_type, @1);
symbol_make_alias ($1, $2, @$);
}
| ID INT string_as_id
{
symbol_class_set ($1, current_class, @1);
symbol_type_set ($1, current_type, @1);
symbol_user_token_number_set ($1, $2, @2);
symbol_make_alias ($1, $3, @$);
}
;
/* One or more symbol definitions. */
symbol_defs.1:
symbol_def
{;}
| symbol_defs.1 symbol_def
{;}
;
/*------------------------------------------.
| The grammar section: between the two %%. |
`------------------------------------------*/
grammar:
rules_or_grammar_declaration
| grammar rules_or_grammar_declaration
;
/* As a Bison extension, one can use the grammar declarations in the
body of the grammar. But to remain LALR(1), they must be ended
with a semi-colon. */
rules_or_grammar_declaration:
rules
| grammar_declaration ";"
{
if (yacc_flag)
complain_at (@$, _("POSIX forbids declarations in the grammar"));
}
| error ";"
{
yyerrok;
}
;
rules:
ID ":" { current_lhs = $1; current_lhs_location = @1; } rhses.1 ";"
{;}
;
rhses.1:
rhs { grammar_rule_end (@1); }
| rhses.1 "|" rhs { grammar_rule_end (@3); }
;
rhs:
/* Nothing. */
{ grammar_rule_begin (current_lhs, current_lhs_location); }
| rhs symbol
{ grammar_current_rule_symbol_append ($2, @2); }
| rhs action
{ grammar_current_rule_action_append ($2, @2); }
| rhs "%prec" symbol
{ grammar_current_rule_prec_set ($3, @3); }
| rhs "%dprec" INT
{ grammar_current_rule_dprec_set ($3, @3); }
| rhs "%merge" TYPE
{ grammar_current_rule_merge_set ($3, @3); }
;
symbol:
ID { $$ = $1; }
| string_as_id { $$ = $1; }
| CHARACTER { $$ = symbol_get ($1, @1); }
;
action:
BRACED_CODE
{ $$ = $1; }
;
/* A string used as an ID: we have to keep the quotes. */
string_as_id:
STRING
{
$$ = symbol_get ($1, @1);
symbol_class_set ($$, token_sym, @1);
}
;
/* A string used for its contents. Strip the quotes. */
string_content:
STRING
{
$$ = $1 + 1;
$$[strlen ($$) - 1] = '\0';
};
epilogue.opt:
/* Nothing. */
{
$$ = xstrdup ("");
}
| "%%" EPILOGUE
{
$$ = $2;
}
;
semi_colon.opt:
/* Nothing. */
| ";"
;
%%
/*------------------------------------------------------------------.
| When debugging the parser, display tokens' locations and values. |
`------------------------------------------------------------------*/
static void
yyprint (FILE *file,
int type, const yystype *value)
{
fputc (' ', file);
switch (type)
{
case CHARACTER:
fprintf (file, " = '%s'", value->string);
break;
case ID:
fprintf (file, " = %s", value->symbol->tag);
break;
case INT:
fprintf (file, " = %d", value->integer);
break;
case STRING:
fprintf (file, " = \"%s\"", value->string);
break;
case TYPE:
fprintf (file, " = <%s>", value->string);
break;
case BRACED_CODE:
case PROLOGUE:
case EPILOGUE:
fprintf (file, " = {{ %s }}", value->string);
break;
}
}
void
gram_error (location_t *yylloc, const char *msg)
{
complain_at (*yylloc, "%s", msg);
}