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29d29c8fff612552f253342caa5fcee70b713490
bison/src/reader.c
Akim Demaille 30171f79ab * src/LR0.c (new_state): Recognize the final state by the fact it 
is reached by eoftoken.
(insert_start_shifting_state, insert_eof_shifting_state)
(insert_accepting_state, augment_automaton): Remove, since now
these states are automatically computed from the initial state.
(generate_states): Adjust.
* src/print.c: When reporting a rule number to the user, substract
1, so that the axiom rule is rule 0, and the first user rule is 1.
* src/reduce.c: Likewise.
* src/print_graph.c (print_core): For the time being, just as for
the report, depend upon --trace-flags to dump the full set of
items.
* src/reader.c (readgram): Once the grammar read, insert the rule
0: `$axiom: START-SYMBOL $'.
* tests/set.at: Adjust: rule 0 is now displayed, and since the
number of the states has changed (the final state is no longer
necessarily the last), catch up.
2001-12-27 18:13:47 +00:00

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/* Input parser for bison
Copyright 1984, 1986, 1989, 1992, 1998, 2000, 2001
Free Software Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
Bison 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.
Bison 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 Bison; see the file COPYING. If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include "system.h"
#include "quotearg.h"
#include "quote.h"
#include "getargs.h"
#include "files.h"
#include "symtab.h"
#include "options.h"
#include "lex.h"
#include "gram.h"
#include "complain.h"
#include "output.h"
#include "reader.h"
#include "conflicts.h"
#include "muscle_tab.h"
typedef struct symbol_list
{
struct symbol_list *next;
bucket *sym;
int line;
/* The action is attached to the LHS of a rule. */
const char *action;
int action_line;
/* The guard is attached to the LHS of a rule. */
const char *guard;
int guard_line;
bucket *ruleprec;
} symbol_list;
int lineno;
char **tags;
short *user_toknums;
static symbol_list *grammar;
static int start_flag;
static bucket *startval;
/* Nonzero if components of semantic values are used, implying
they must be unions. */
static int value_components_used;
/* Nonzero if %union has been seen. */
static int typed;
/* Incremented for each %left, %right or %nonassoc seen */
static int lastprec;
static bucket *errtoken = NULL;
static bucket *undeftoken = NULL;
static bucket *eoftoken = NULL;
static bucket *axiom = NULL;
static symbol_list *
symbol_list_new (bucket *sym)
{
symbol_list *res = XMALLOC (symbol_list, 1);
res->next = NULL;
res->sym = sym;
res->line = lineno;
res->action = NULL;
res->action_line = 0;
res->guard = NULL;
res->guard_line = 0;
res->ruleprec = NULL;
return res;
}
/*===================\
| Low level lexing. |
\===================*/
static void
skip_to_char (int target)
{
int c;
if (target == '\n')
complain (_(" Skipping to next \\n"));
else
complain (_(" Skipping to next %c"), target);
do
c = skip_white_space ();
while (c != target && c != EOF);
if (c != EOF)
ungetc (c, finput);
}
/*---------------------------------------------------------.
| Read a signed integer from STREAM and return its value. |
`---------------------------------------------------------*/
static inline int
read_signed_integer (FILE *stream)
{
int c = getc (stream);
int sign = 1;
int n = 0;
if (c == '-')
{
c = getc (stream);
sign = -1;
}
while (isdigit (c))
{
n = 10 * n + (c - '0');
c = getc (stream);
}
ungetc (c, stream);
return sign * n;
}
/*--------------------------------------------------------------.
| Get the data type (alternative in the union) of the value for |
| symbol N in rule RULE. |
`--------------------------------------------------------------*/
static char *
get_type_name (int n, symbol_list *rule)
{
int i;
symbol_list *rp;
if (n < 0)
{
complain (_("invalid $ value"));
return NULL;
}
rp = rule;
i = 0;
while (i < n)
{
rp = rp->next;
if (rp == NULL || rp->sym == NULL)
{
complain (_("invalid $ value"));
return NULL;
}
i++;
}
return rp->sym->type_name;
}
/*------------------------------------------------------------.
| Dump the string from FIN to OOUT if non null. MATCH is the |
| delimiter of the string (either ' or "). |
`------------------------------------------------------------*/
static inline void
copy_string2 (FILE *fin, struct obstack *oout, int match, int store)
{
int c;
if (store)
obstack_1grow (oout, match);
c = getc (fin);
while (c != match)
{
if (c == EOF)
fatal (_("unterminated string at end of file"));
if (c == '\n')
{
complain (_("unterminated string"));
ungetc (c, fin);
c = match; /* invent terminator */
continue;
}
obstack_1grow (oout, c);
if (c == '\\')
{
c = getc (fin);
if (c == EOF)
fatal (_("unterminated string at end of file"));
obstack_1grow (oout, c);
if (c == '\n')
lineno++;
}
c = getc (fin);
}
if (store)
obstack_1grow (oout, c);
}
/* FIXME. */
static inline void
copy_string (FILE *fin, struct obstack *oout, int match)
{
copy_string2 (fin, oout, match, 1);
}
/* FIXME. */
static inline void
copy_identifier (FILE *fin, struct obstack *oout)
{
int c;
while (isalnum (c = getc (fin)) || c == '_')
obstack_1grow (oout, c);
ungetc (c, fin);
}
/*------------------------------------------------------------------.
| Dump the wannabee comment from IN to OOUT. In fact we just saw a |
| `/', which might or might not be a comment. In any case, copy |
| what we saw. |
`------------------------------------------------------------------*/
static inline void
copy_comment (FILE *fin, struct obstack *oout)
{
int cplus_comment;
int ended;
int c;
/* We read a `/', output it. */
obstack_1grow (oout, '/');
switch ((c = getc (fin)))
{
case '/':
cplus_comment = 1;
break;
case '*':
cplus_comment = 0;
break;
default:
ungetc (c, fin);
return;
}
obstack_1grow (oout, c);
c = getc (fin);
ended = 0;
while (!ended)
{
if (!cplus_comment && c == '*')
{
while (c == '*')
{
obstack_1grow (oout, c);
c = getc (fin);
}
if (c == '/')
{
obstack_1grow (oout, c);
ended = 1;
}
}
else if (c == '\n')
{
lineno++;
obstack_1grow (oout, c);
if (cplus_comment)
ended = 1;
else
c = getc (fin);
}
else if (c == EOF)
fatal (_("unterminated comment"));
else
{
obstack_1grow (oout, c);
c = getc (fin);
}
}
}
/*-----------------------------------------------------------------.
| FIN is pointing to a location (i.e., a `@'). Output to OOUT a |
| reference to this location. STACK_OFFSET is the number of values |
| in the current rule so far, which says where to find `$0' with |
| respect to the top of the stack. |
`-----------------------------------------------------------------*/
static inline void
copy_at (FILE *fin, struct obstack *oout, int stack_offset)
{
int c;
c = getc (fin);
if (c == '$')
{
obstack_sgrow (oout, "yyloc");
locations_flag = 1;
}
else if (isdigit (c) || c == '-')
{
int n;
ungetc (c, fin);
n = read_signed_integer (fin);
if (n > stack_offset)
complain (_("invalid value: %s%d"), "@", n);
else
{
/* Offset is always 0 if parser has already popped the stack
pointer. */
obstack_fgrow1 (oout, "yylsp[%d]",
n - (semantic_parser ? 0 : stack_offset));
locations_flag = 1;
}
}
else
{
char buf[] = "@c";
buf[1] = c;
complain (_("%s is invalid"), quote (buf));
}
}
/*-------------------------------------------------------------------.
| FIN is pointing to a wannabee semantic value (i.e., a `$'). |
| |
| Possible inputs: $[<TYPENAME>]($|integer) |
| |
| Output to OOUT a reference to this semantic value. STACK_OFFSET is |
| the number of values in the current rule so far, which says where |
| to find `$0' with respect to the top of the stack. |
`-------------------------------------------------------------------*/
static inline void
copy_dollar (FILE *fin, struct obstack *oout,
symbol_list *rule, int stack_offset)
{
int c = getc (fin);
const char *type_name = NULL;
/* Get the type name if explicit. */
if (c == '<')
{
read_type_name (fin);
type_name = token_buffer;
value_components_used = 1;
c = getc (fin);
}
if (c == '$')
{
obstack_sgrow (oout, "yyval");
if (!type_name)
type_name = get_type_name (0, rule);
if (type_name)
obstack_fgrow1 (oout, ".%s", type_name);
if (!type_name && typed)
complain (_("$$ of `%s' has no declared type"),
rule->sym->tag);
}
else if (isdigit (c) || c == '-')
{
int n;
ungetc (c, fin);
n = read_signed_integer (fin);
if (n > stack_offset)
complain (_("invalid value: %s%d"), "$", n);
else
{
if (!type_name && n > 0)
type_name = get_type_name (n, rule);
/* Offset is always 0 if parser has already popped the stack
pointer. */
obstack_fgrow1 (oout, "yyvsp[%d]",
n - (semantic_parser ? 0 : stack_offset));
if (type_name)
obstack_fgrow1 (oout, ".%s", type_name);
if (!type_name && typed)
complain (_("$%d of `%s' has no declared type"),
n, rule->sym->tag);
}
}
else
{
char buf[] = "$c";
buf[1] = c;
complain (_("%s is invalid"), quote (buf));
}
}
/*-------------------------------------------------------------------.
| Copy the contents of a `%{ ... %}' into the definitions file. The |
| `%{' has already been read. Return after reading the `%}'. |
`-------------------------------------------------------------------*/
static void
copy_definition (void)
{
int c;
/* -1 while reading a character if prev char was %. */
int after_percent;
if (!no_lines_flag)
{
obstack_fgrow2 (&attrs_obstack, muscle_find ("linef"),
lineno, quotearg_style (c_quoting_style,
muscle_find ("filename")));
}
after_percent = 0;
c = getc (finput);
for (;;)
{
switch (c)
{
case '\n':
obstack_1grow (&attrs_obstack, c);
lineno++;
break;
case '%':
after_percent = -1;
break;
case '\'':
case '"':
copy_string (finput, &attrs_obstack, c);
break;
case '/':
copy_comment (finput, &attrs_obstack);
break;
case EOF:
fatal ("%s", _("unterminated `%{' definition"));
default:
obstack_1grow (&attrs_obstack, c);
}
c = getc (finput);
if (after_percent)
{
if (c == '}')
return;
obstack_1grow (&attrs_obstack, '%');
}
after_percent = 0;
}
}
/*-------------------------------------------------------------------.
| Parse what comes after %token or %nterm. For %token, WHAT_IS is |
| token_sym and WHAT_IS_NOT is nterm_sym. For %nterm, the arguments |
| are reversed. |
`-------------------------------------------------------------------*/
static void
parse_token_decl (symbol_class what_is, symbol_class what_is_not)
{
token_t token = tok_undef;
char *typename = NULL;
/* The symbol being defined. */
struct bucket *symbol = NULL;
/* After `%token' and `%nterm', any number of symbols maybe be
defined. */
for (;;)
{
int tmp_char = ungetc (skip_white_space (), finput);
/* `%' (for instance from `%token', or from `%%' etc.) is the
only valid means to end this declaration. */
if (tmp_char == '%')
return;
if (tmp_char == EOF)
fatal (_("Premature EOF after %s"), token_buffer);
token = lex ();
if (token == tok_comma)
{
symbol = NULL;
continue;
}
if (token == tok_typename)
{
typename = xstrdup (token_buffer);
value_components_used = 1;
symbol = NULL;
}
else if (token == tok_identifier && *symval->tag == '\"' && symbol)
{
if (symval->alias)
warn (_("symbol `%s' used more than once as a literal string"),
symval->tag);
else if (symbol->alias)
warn (_("symbol `%s' given more than one literal string"),
symbol->tag);
else
{
symval->class = token_sym;
symval->type_name = typename;
symval->user_token_number = symbol->user_token_number;
symbol->user_token_number = SALIAS;
symval->alias = symbol;
symbol->alias = symval;
/* symbol and symval combined are only one symbol */
nsyms--;
}
symbol = NULL;
}
else if (token == tok_identifier)
{
int oldclass = symval->class;
symbol = symval;
if (symbol->class == what_is_not)
complain (_("symbol %s redefined"), symbol->tag);
symbol->class = what_is;
if (what_is == nterm_sym && oldclass != nterm_sym)
symbol->value = nvars++;
if (typename)
{
if (symbol->type_name == NULL)
symbol->type_name = typename;
else if (strcmp (typename, symbol->type_name) != 0)
complain (_("type redeclaration for %s"), symbol->tag);
}
}
else if (symbol && token == tok_number)
{
symbol->user_token_number = numval;
/* User defined EOF token? */
if (numval == 0)
eoftoken = symbol;
}
else
{
complain (_("`%s' is invalid in %s"),
token_buffer,
(what_is == token_sym) ? "%token" : "%nterm");
skip_to_char ('%');
}
}
}
/*------------------------------.
| Parse what comes after %start |
`------------------------------*/
static void
parse_start_decl (void)
{
if (start_flag)
complain (_("multiple %s declarations"), "%start");
if (lex () != tok_identifier)
complain (_("invalid %s declaration"), "%start");
else
{
start_flag = 1;
startval = symval;
}
}
/*-----------------------------------------------------------.
| read in a %type declaration and record its information for |
| get_type_name to access |
`-----------------------------------------------------------*/
static void
parse_type_decl (void)
{
char *name;
if (lex () != tok_typename)
{
complain ("%s", _("%type declaration has no <typename>"));
skip_to_char ('%');
return;
}
name = xstrdup (token_buffer);
for (;;)
{
token_t t;
int tmp_char = ungetc (skip_white_space (), finput);
if (tmp_char == '%')
return;
if (tmp_char == EOF)
fatal (_("Premature EOF after %s"), token_buffer);
t = lex ();
switch (t)
{
case tok_comma:
case tok_semicolon:
break;
case tok_identifier:
if (symval->type_name == NULL)
symval->type_name = name;
else if (strcmp (name, symval->type_name) != 0)
complain (_("type redeclaration for %s"), symval->tag);
break;
default:
complain (_("invalid %%type declaration due to item: %s"),
token_buffer);
skip_to_char ('%');
}
}
}
/*----------------------------------------------------------------.
| Read in a %left, %right or %nonassoc declaration and record its |
| information. |
`----------------------------------------------------------------*/
static void
parse_assoc_decl (associativity assoc)
{
char *name = NULL;
int prev = 0;
lastprec++; /* Assign a new precedence level, never 0. */
for (;;)
{
token_t t;
int tmp_char = ungetc (skip_white_space (), finput);
if (tmp_char == '%')
return;
if (tmp_char == EOF)
fatal (_("Premature EOF after %s"), token_buffer);
t = lex ();
switch (t)
{
case tok_typename:
name = xstrdup (token_buffer);
break;
case tok_comma:
break;
case tok_identifier:
if (symval->prec != 0)
complain (_("redefining precedence of %s"), symval->tag);
symval->prec = lastprec;
symval->assoc = assoc;
if (symval->class == nterm_sym)
complain (_("symbol %s redefined"), symval->tag);
symval->class = token_sym;
if (name)
{ /* record the type, if one is specified */
if (symval->type_name == NULL)
symval->type_name = name;
else if (strcmp (name, symval->type_name) != 0)
complain (_("type redeclaration for %s"), symval->tag);
}
break;
case tok_number:
if (prev == tok_identifier)
{
symval->user_token_number = numval;
}
else
{
complain (_
("invalid text (%s) - number should be after identifier"),
token_buffer);
skip_to_char ('%');
}
break;
case tok_semicolon:
return;
default:
complain (_("unexpected item: %s"), token_buffer);
skip_to_char ('%');
}
prev = t;
}
}
/*--------------------------------------------------------------.
| Copy the union declaration into the stype muscle |
| (and fdefines), where it is made into the definition of |
| YYSTYPE, the type of elements of the parser value stack. |
`--------------------------------------------------------------*/
static void
parse_union_decl (void)
{
int c;
int count = 0;
bool done = FALSE;
struct obstack union_obstack;
if (typed)
complain (_("multiple %s declarations"), "%union");
typed = 1;
obstack_init (&union_obstack);
obstack_sgrow (&union_obstack, "union");
while (!done)
{
c = xgetc (finput);
/* If C contains '/', it is output by copy_comment (). */
if (c != '/')
obstack_1grow (&union_obstack, c);
switch (c)
{
case '\n':
lineno++;
break;
case '/':
copy_comment (finput, &union_obstack);
break;
case '{':
count++;
break;
case '}':
/* FIXME: Errr. How could this happen???. --akim */
if (count == 0)
complain (_("unmatched %s"), "`}'");
count--;
if (!count)
done = TRUE;
break;
}
}
/* JF don't choke on trailing semi */
c = skip_white_space ();
if (c != ';')
ungetc (c, finput);
obstack_1grow (&union_obstack, 0);
muscle_insert ("stype", obstack_finish (&union_obstack));
}
/*-------------------------------------------------------.
| Parse the declaration %expect N which says to expect N |
| shift-reduce conflicts. |
`-------------------------------------------------------*/
static void
parse_expect_decl (void)
{
int c = skip_white_space ();
ungetc (c, finput);
if (!isdigit (c))
complain (_("argument of %%expect is not an integer"));
else
expected_conflicts = read_signed_integer (finput);
}
/*-------------------------------------------------------------------.
| Parse what comes after %thong. the full syntax is |
| |
| %thong <type> token number literal |
| |
| the <type> or number may be omitted. The number specifies the |
| user_token_number. |
| |
| Two symbols are entered in the table, one for the token symbol and |
| one for the literal. Both are given the <type>, if any, from the |
| declaration. The ->user_token_number of the first is SALIAS and |
| the ->user_token_number of the second is set to the number, if |
| any, from the declaration. The two symbols are linked via |
| pointers in their ->alias fields. |
| |
| During OUTPUT_DEFINES_TABLE, the symbol is reported thereafter, |
| only the literal string is retained it is the literal string that |
| is output to yytname |
`-------------------------------------------------------------------*/
static void
parse_thong_decl (void)
{
token_t token;
struct bucket *symbol;
char *typename = 0;
int usrtoknum = SUNDEF;
token = lex (); /* fetch typename or first token */
if (token == tok_typename)
{
typename = xstrdup (token_buffer);
value_components_used = 1;
token = lex (); /* fetch first token */
}
/* process first token */
if (token != tok_identifier)
{
complain (_("unrecognized item %s, expected an identifier"),
token_buffer);
skip_to_char ('%');
return;
}
symval->class = token_sym;
symval->type_name = typename;
symval->user_token_number = SALIAS;
symbol = symval;
token = lex (); /* get number or literal string */
if (token == tok_number)
{
usrtoknum = numval;
token = lex (); /* okay, did number, now get literal */
}
/* process literal string token */
if (token != tok_identifier || *symval->tag != '\"')
{
complain (_("expected string constant instead of %s"), token_buffer);
skip_to_char ('%');
return;
}
symval->class = token_sym;
symval->type_name = typename;
symval->user_token_number = usrtoknum;
symval->alias = symbol;
symbol->alias = symval;
/* symbol and symval combined are only one symbol. */
nsyms--;
}
static void
parse_muscle_decl (void)
{
int ch = ungetc (skip_white_space (), finput);
char *muscle_key;
char *muscle_value;
/* Read key. */
if (!isalpha (ch) && ch != '_')
{
complain (_("invalid %s declaration"), "%define");
skip_to_char ('%');
return;
}
copy_identifier (finput, &muscle_obstack);
obstack_1grow (&muscle_obstack, 0);
muscle_key = obstack_finish (&muscle_obstack);
/* Read value. */
ch = skip_white_space ();
if (ch != '"')
{
ungetc (ch, finput);
if (ch != EOF)
{
complain (_("invalid %s declaration"), "%define");
skip_to_char ('%');
return;
}
else
fatal (_("Premature EOF after %s"), "\"");
}
copy_string2 (finput, &muscle_obstack, '"', 0);
obstack_1grow (&muscle_obstack, 0);
muscle_value = obstack_finish (&muscle_obstack);
/* Store the (key, value) pair in the environment. */
muscle_insert (muscle_key, muscle_value);
}
/*---------------------------------.
| Parse a double quoted parameter. |
`---------------------------------*/
static const char *
parse_dquoted_param (const char *from)
{
struct obstack param_obstack;
const char *param = NULL;
int c;
obstack_init (&param_obstack);
c = skip_white_space ();
if (c != '"')
{
complain (_("invalid %s declaration"), from);
ungetc (c, finput);
skip_to_char ('%');
return NULL;
}
while ((c = literalchar ()) != '"')
obstack_1grow (&param_obstack, c);
obstack_1grow (&param_obstack, '\0');
param = obstack_finish (&param_obstack);
if (c != '"' || strlen (param) == 0)
{
complain (_("invalid %s declaration"), from);
if (c != '"')
ungetc (c, finput);
skip_to_char ('%');
return NULL;
}
return param;
}
/*----------------------------------.
| Parse what comes after %skeleton. |
`----------------------------------*/
static void
parse_skel_decl (void)
{
skeleton = parse_dquoted_param ("%skeleton");
}
/*----------------------------------------------------------------.
| Read from finput until `%%' is seen. Discard the `%%'. Handle |
| any `%' declarations, and copy the contents of any `%{ ... %}' |
| groups to ATTRS_OBSTACK. |
`----------------------------------------------------------------*/
static void
read_declarations (void)
{
for (;;)
{
int c = skip_white_space ();
if (c == '%')
{
token_t tok = parse_percent_token ();
switch (tok)
{
case tok_two_percents:
return;
case tok_percent_left_curly:
copy_definition ();
break;
case tok_token:
parse_token_decl (token_sym, nterm_sym);
break;
case tok_nterm:
parse_token_decl (nterm_sym, token_sym);
break;
case tok_type:
parse_type_decl ();
break;
case tok_start:
parse_start_decl ();
break;
case tok_union:
parse_union_decl ();
break;
case tok_expect:
parse_expect_decl ();
break;
case tok_thong:
parse_thong_decl ();
break;
case tok_left:
parse_assoc_decl (left_assoc);
break;
case tok_right:
parse_assoc_decl (right_assoc);
break;
case tok_nonassoc:
parse_assoc_decl (non_assoc);
break;
case tok_define:
parse_muscle_decl ();
break;
case tok_skel:
parse_skel_decl ();
break;
case tok_noop:
break;
case tok_stropt:
case tok_intopt:
case tok_obsolete:
abort ();
break;
case tok_illegal:
default:
complain (_("unrecognized: %s"), token_buffer);
skip_to_char ('%');
}
}
else if (c == EOF)
fatal (_("no input grammar"));
else
{
char buf[] = "c";
buf[0] = c;
complain (_("unknown character: %s"), quote (buf));
skip_to_char ('%');
}
}
}
/*-------------------------------------------------------------------.
| Assuming that a `{' has just been seen, copy everything up to the |
| matching `}' into the actions file. STACK_OFFSET is the number of |
| 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. |
`-------------------------------------------------------------------*/
static void
parse_braces (symbol_list *rule, int stack_offset)
{
int c;
int count;
count = 1;
while (count > 0)
{
while ((c = getc (finput)) != '}')
switch (c)
{
case '\n':
obstack_1grow (&action_obstack, c);
lineno++;
break;
case '{':
obstack_1grow (&action_obstack, c);
count++;
break;
case '\'':
case '"':
copy_string (finput, &action_obstack, c);
break;
case '/':
copy_comment (finput, &action_obstack);
break;
case '$':
copy_dollar (finput, &action_obstack,
rule, stack_offset);
break;
case '@':
copy_at (finput, &action_obstack,
stack_offset);
break;
case EOF:
fatal (_("unmatched %s"), "`{'");
default:
obstack_1grow (&action_obstack, c);
}
/* Above loop exits when C is '}'. */
if (--count)
{
obstack_1grow (&action_obstack, c);
c = getc (finput);
}
}
obstack_1grow (&action_obstack, '\0');
}
static void
parse_action (symbol_list *rule, int stack_offset)
{
rule->action_line = lineno;
parse_braces (rule, stack_offset);
rule->action = obstack_finish (&action_obstack);
}
static void
parse_guard (symbol_list *rule, int stack_offset)
{
token_t t = lex ();
if (t != tok_left_curly)
complain (_("invalid %s declaration"), "%guard");
rule->guard_line = lineno;
parse_braces (rule, stack_offset);
rule->guard = obstack_finish (&action_obstack);
}
/*-------------------------------------------------------------------.
| Generate a dummy symbol, a nonterminal, whose name cannot conflict |
| with the user's names. |
`-------------------------------------------------------------------*/
static bucket *
gensym (void)
{
/* Incremented for each generated symbol */
static int gensym_count = 0;
static char buf[256];
bucket *sym;
sprintf (buf, "@%d", ++gensym_count);
token_buffer = buf;
sym = getsym (token_buffer);
sym->class = nterm_sym;
sym->value = nvars++;
return sym;
}
/*-------------------------------------------------------------------.
| Parse the input grammar into a one symbol_list structure. Each |
| rule is represented by a sequence of symbols: the left hand side |
| followed by the contents of the right hand side, followed by a |
| 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. |
| |
| Bison used to allow some %directives in the rules sections, but |
| this is no longer consider appropriate: (i) the documented grammar |
| doesn't claim it, (ii), it would promote bad style, (iii), error |
| recovery for %directives consists in skipping the junk until a `%' |
| is seen and helrp synchronizing. This scheme is definitely wrong |
| in the rules section. |
`-------------------------------------------------------------------*/
static void
readgram (void)
{
token_t t;
bucket *lhs = NULL;
symbol_list *p = NULL;
symbol_list *p1 = NULL;
bucket *bp;
/* Points to first symbol_list of current rule. its symbol is the
lhs of the rule. */
symbol_list *crule = NULL;
/* Points to the symbol_list preceding crule. */
symbol_list *crule1 = NULL;
t = lex ();
while (t != tok_two_percents && t != tok_eof)
if (t == tok_identifier || t == tok_bar)
{
int action_flag = 0;
/* Number of symbols in rhs of this rule so far */
int rulelength = 0;
int xactions = 0; /* JF for error checking */
bucket *first_rhs = 0;
if (t == tok_identifier)
{
lhs = symval;
if (!start_flag)
{
startval = lhs;
start_flag = 1;
}
t = lex ();
if (t != tok_colon)
{
complain (_("ill-formed rule: initial symbol not followed by colon"));
unlex (t);
}
}
if (nrules == 0 && t == tok_bar)
{
complain (_("grammar starts with vertical bar"));
lhs = symval; /* BOGUS: use a random symval */
}
/* start a new rule and record its lhs. */
nrules++;
nitems++;
p = symbol_list_new (lhs);
crule1 = p1;
if (p1)
p1->next = p;
else
grammar = p;
p1 = p;
crule = p;
/* mark the rule's lhs as a nonterminal if not already so. */
if (lhs->class == unknown_sym)
{
lhs->class = nterm_sym;
lhs->value = nvars;
nvars++;
}
else if (lhs->class == token_sym)
complain (_("rule given for %s, which is a token"), lhs->tag);
/* read the rhs of the rule. */
for (;;)
{
t = lex ();
if (t == tok_prec)
{
t = lex ();
crule->ruleprec = symval;
t = lex ();
}
if (!(t == tok_identifier || t == tok_left_curly))
break;
/* If next token is an identifier, see if a colon follows it.
If one does, exit this rule now. */
if (t == tok_identifier)
{
bucket *ssave;
token_t t1;
ssave = symval;
t1 = lex ();
unlex (t1);
symval = ssave;
if (t1 == tok_colon)
break;
if (!first_rhs) /* JF */
first_rhs = symval;
/* Not followed by colon =>
process as part of this rule's rhs. */
}
/* If we just passed an action, that action was in the middle
of a rule, so make a dummy rule to reduce it to a
non-terminal. */
if (action_flag)
{
/* Since the action was written out with this rule's
number, we must give the new rule this number by
inserting the new rule before it. */
/* Make a dummy nonterminal, a gensym. */
bucket *sdummy = gensym ();
/* Make a new rule, whose body is empty, before the
current one, so that the action just read can
belong to it. */
nrules++;
nitems++;
p = symbol_list_new (sdummy);
/* Attach its lineno to that of the host rule. */
p->line = crule->line;
if (crule1)
crule1->next = p;
else
grammar = p;
/* End of the rule. */
crule1 = symbol_list_new (NULL);
crule1->next = crule;
p->next = crule1;
/* Insert the dummy generated by that rule into this
rule. */
nitems++;
p = symbol_list_new (sdummy);
p1->next = p;
p1 = p;
action_flag = 0;
}
if (t == tok_identifier)
{
nitems++;
p = symbol_list_new (symval);
p1->next = p;
p1 = p;
}
else /* handle an action. */
{
parse_action (crule, rulelength);
action_flag = 1;
xactions++; /* JF */
}
rulelength++;
} /* end of read rhs of rule */
/* Put an empty link in the list to mark the end of this rule */
p = symbol_list_new (NULL);
p1->next = p;
p1 = p;
if (t == tok_prec)
{
complain (_("two @prec's in a row"));
t = lex ();
crule->ruleprec = symval;
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 */
if (action_flag)
complain (_("two actions at end of one rule"));
parse_action (crule, rulelength);
action_flag = 1;
xactions++; /* -wjh */
t = lex ();
}
/* If $$ is being set in default way, report if any type
mismatch. */
else if (!xactions
&& first_rhs && lhs->type_name != first_rhs->type_name)
{
if (lhs->type_name == 0
|| first_rhs->type_name == 0
|| strcmp (lhs->type_name, first_rhs->type_name))
complain (_("type clash (`%s' `%s') on default action"),
lhs->type_name ? lhs->type_name : "",
first_rhs->type_name ? first_rhs->type_name : "");
}
/* Warn if there is no default for $$ but we need one. */
else if (!xactions && !first_rhs && lhs->type_name != 0)
complain (_("empty rule for typed nonterminal, and no action"));
if (t == tok_semicolon)
t = lex ();
}
else
{
complain (_("invalid input: %s"), quote (token_buffer));
t = lex ();
}
/* Insert the initial rule:
axiom: %start EOF. */
p = symbol_list_new (axiom);
p->next = symbol_list_new (startval);
p->next->next = symbol_list_new (eoftoken);
p->next->next->next = symbol_list_new (NULL);
p->next->next->next->next = grammar;
nrules += 1;
nitems += 3;
grammar = p;
startval = axiom;
/* grammar has been read. Do some checking */
if (nsyms > MAXSHORT)
fatal (_("too many symbols (tokens plus nonterminals); maximum %d"),
MAXSHORT);
if (nrules == 0)
fatal (_("no rules in the input grammar"));
/* Report any undefined symbols and consider them nonterminals. */
for (bp = firstsymbol; bp; bp = bp->next)
if (bp->class == unknown_sym)
{
complain (_
("symbol %s is used, but is not defined as a token and has no rules"),
bp->tag);
bp->class = nterm_sym;
bp->value = nvars++;
}
ntokens = nsyms - nvars;
}
/* At the end of the grammar file, some C source code must
be stored. It is going to be associated to the epilogue
directive. */
static void
read_additionnal_code (void)
{
char c;
struct obstack el_obstack;
obstack_init (&el_obstack);
if (!no_lines_flag)
{
obstack_fgrow2 (&el_obstack, muscle_find ("linef"),
lineno, quotearg_style (c_quoting_style,
muscle_find ("filename")));
}
while ((c = getc (finput)) != EOF)
obstack_1grow (&el_obstack, c);
obstack_1grow (&el_obstack, 0);
muscle_insert ("epilogue", obstack_finish (&el_obstack));
}
/*------------------------------------------------------------------.
| Set TOKEN_TRANSLATIONS. Check that no two symbols share the same |
| number. |
`------------------------------------------------------------------*/
static void
token_translations_init (void)
{
bucket *bp = NULL;
int i;
token_translations = XCALLOC (short, max_user_token_number + 1);
/* Initialize all entries for literal tokens to 2, the internal
token number for $undefined., which represents all invalid
inputs. */
for (i = 0; i <= max_user_token_number; i++)
token_translations[i] = 2;
for (bp = firstsymbol; bp; bp = bp->next)
{
/* Non-terminal? */
if (bp->value >= ntokens)
continue;
/* A token string alias? */
if (bp->user_token_number == SALIAS)
continue;
assert (bp->user_token_number != SUNDEF);
/* A token which translation has already been set? */
if (token_translations[bp->user_token_number] != 2)
complain (_("tokens %s and %s both assigned number %d"),
tags[token_translations[bp->user_token_number]],
bp->tag, bp->user_token_number);
token_translations[bp->user_token_number] = bp->value;
}
}
/*------------------------------------------------------------------.
| Assign symbol numbers, and write definition of token names into |
| FDEFINES. Set up vectors TAGS and SPREC of names and precedences |
| of symbols. |
`------------------------------------------------------------------*/
static void
packsymbols (void)
{
bucket *bp = NULL;
int tokno = 1;
int last_user_token_number;
tags = XCALLOC (char *, nsyms + 1);
user_toknums = XCALLOC (short, nsyms + 1);
sprec = XCALLOC (short, nsyms);
sassoc = XCALLOC (short, nsyms);
max_user_token_number = 256;
last_user_token_number = 256;
for (bp = firstsymbol; bp; bp = bp->next)
{
if (bp->class == nterm_sym)
{
bp->value += ntokens;
}
else if (bp->alias)
{
/* This symbol and its alias are a single token defn.
Allocate a tokno, and assign to both check agreement of
prec and assoc fields and make both the same */
if (bp->value == -1)
{
if (bp == eoftoken || bp->alias == eoftoken)
bp->value = bp->alias->value = 0;
else
{
bp->value = bp->alias->value = tokno++;
}
}
if (bp->prec != bp->alias->prec)
{
if (bp->prec != 0 && bp->alias->prec != 0
&& bp->user_token_number == SALIAS)
complain (_("conflicting precedences for %s and %s"),
bp->tag, bp->alias->tag);
if (bp->prec != 0)
bp->alias->prec = bp->prec;
else
bp->prec = bp->alias->prec;
}
if (bp->assoc != bp->alias->assoc)
{
if (bp->assoc != 0 && bp->alias->assoc != 0
&& bp->user_token_number == SALIAS)
complain (_("conflicting assoc values for %s and %s"),
bp->tag, bp->alias->tag);
if (bp->assoc != 0)
bp->alias->assoc = bp->assoc;
else
bp->assoc = bp->alias->assoc;
}
/* Do not do processing below for SALIASs. */
if (bp->user_token_number == SALIAS)
continue;
}
else /* bp->class == token_sym */
{
if (bp == eoftoken)
bp->value = 0;
else
bp->value = tokno++;
}
if (bp->class == token_sym)
{
if (bp->user_token_number == SUNDEF)
bp->user_token_number = ++last_user_token_number;
if (bp->user_token_number > max_user_token_number)
max_user_token_number = bp->user_token_number;
}
tags[bp->value] = bp->tag;
user_toknums[bp->value] = bp->user_token_number;
sprec[bp->value] = bp->prec;
sassoc[bp->value] = bp->assoc;
}
token_translations_init ();
error_token_number = errtoken->value;
if (startval->class == unknown_sym)
fatal (_("the start symbol %s is undefined"), startval->tag);
else if (startval->class == token_sym)
fatal (_("the start symbol %s is a token"), startval->tag);
start_symbol = startval->value;
}
/*---------------------------------------------------------------.
| Save the definition of token names in the `TOKENDEFS' muscle. |
`---------------------------------------------------------------*/
static void
symbols_save (void)
{
struct obstack tokendefs;
bucket *bp;
obstack_init (&tokendefs);
for (bp = firstsymbol; bp; bp = bp->next)
{
char *symbol = bp->tag; /* get symbol */
if (bp->value >= ntokens)
continue;
if (bp->user_token_number == SALIAS)
continue;
if ('\'' == *symbol)
continue; /* skip literal character */
if (bp == errtoken)
continue; /* skip error token */
if ('\"' == *symbol)
{
/* use literal string only if given a symbol with an alias */
if (bp->alias)
symbol = bp->alias->tag;
else
continue;
}
/* Don't #define nonliteral tokens whose names contain periods. */
if (strchr (symbol, '.'))
continue;
obstack_fgrow2 (&tokendefs, "# define %s\t%d\n",
symbol, bp->user_token_number);
if (semantic_parser)
/* FIXME: This is probably wrong, and should be just as
above. --akim. */
obstack_fgrow2 (&tokendefs, "# define T%s\t%d\n", symbol, bp->value);
}
obstack_1grow (&tokendefs, 0);
muscle_insert ("tokendef", xstrdup (obstack_finish (&tokendefs)));
obstack_free (&tokendefs, NULL);
}
/*---------------------------------------------------------------.
| Convert the rules into the representation using RRHS, RLHS and |
| RITEMS. |
`---------------------------------------------------------------*/
static void
packgram (void)
{
int itemno;
int ruleno;
symbol_list *p;
/* We use short to index items. */
if (nitems >= MAXSHORT)
fatal (_("too many items (max %d)"), MAXSHORT);
ritem = XCALLOC (short, nitems + 1);
rule_table = XCALLOC (rule_t, nrules) - 1;
itemno = 0;
ruleno = 1;
p = grammar;
while (p)
{
bucket *ruleprec = p->ruleprec;
rule_table[ruleno].lhs = p->sym->value;
rule_table[ruleno].rhs = itemno;
rule_table[ruleno].line = p->line;
rule_table[ruleno].useful = TRUE;
rule_table[ruleno].action = p->action;
rule_table[ruleno].action_line = p->action_line;
rule_table[ruleno].guard = p->guard;
rule_table[ruleno].guard_line = p->guard_line;
p = p->next;
while (p && p->sym)
{
ritem[itemno++] = p->sym->value;
/* A rule gets by default the precedence and associativity
of the last token in it. */
if (p->sym->class == token_sym)
{
rule_table[ruleno].prec = p->sym->prec;
rule_table[ruleno].assoc = p->sym->assoc;
}
if (p)
p = p->next;
}
/* If this rule has a %prec,
the specified symbol's precedence replaces the default. */
if (ruleprec)
{
rule_table[ruleno].prec = ruleprec->prec;
rule_table[ruleno].assoc = ruleprec->assoc;
rule_table[ruleno].precsym = ruleprec->value;
}
ritem[itemno++] = -ruleno;
ruleno++;
if (p)
p = p->next;
}
ritem[itemno] = 0;
nritems = itemno;
assert (nritems == nitems);
if (trace_flag)
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. |
`-------------------------------------------------------------------*/
void
reader (void)
{
start_flag = 0;
startval = NULL; /* start symbol not specified yet. */
nsyms = 0;
nvars = 0;
nrules = 0;
nitems = 0;
typed = 0;
lastprec = 0;
semantic_parser = 0;
pure_parser = 0;
grammar = NULL;
lex_init ();
lineno = 1;
/* Initialize the muscle obstack. */
obstack_init (&muscle_obstack);
/* Initialize the symbol table. */
tabinit ();
/* Construct the axiom symbol. */
axiom = getsym ("$axiom");
axiom->class = nterm_sym;
axiom->value = nvars++;
/* Construct the error token */
errtoken = getsym ("error");
errtoken->class = token_sym;
errtoken->user_token_number = 256; /* Value specified by POSIX. */
/* Construct a token that represents all undefined literal tokens.
It is always token number 2. */
undeftoken = getsym ("$undefined.");
undeftoken->class = token_sym;
undeftoken->user_token_number = 2;
/* Initialize the obstacks. */
obstack_init (&action_obstack);
obstack_init (&attrs_obstack);
obstack_init (&output_obstack);
finput = xfopen (infile, "r");
/* Read the declaration section. Copy %{ ... %} groups to
TABLE_OBSTACK and FDEFINES file. Also notice any %token, %left,
etc. found there. */
read_declarations ();
/* If the user did not define her EOFTOKEN, do it now. */
if (!eoftoken)
{
eoftoken = getsym ("$");
eoftoken->class = token_sym;
/* Value specified by POSIX. */
eoftoken->user_token_number = 0;
}
/* Read in the grammar, build grammar in list form. Write out
guards and actions. */
readgram ();
/* Some C code is given at the end of the grammar file. */
read_additionnal_code ();
lex_free ();
xfclose (finput);
/* Assign the symbols their symbol numbers. Write #defines for the
token symbols into FDEFINES if requested. */
packsymbols ();
/* Save them. */
symbols_save ();
/* Convert the grammar into the format described in gram.h. */
packgram ();
}
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