/* Input parser for bison
- Copyright (C) 1984, 1986, 1989, 1992 Free Software Foundation, Inc.
+ Copyright (C) 1984, 1986, 1989, 1992, 1998, 2000, 2001, 2002
+ Free Software Foundation, Inc.
-This file is part of Bison, the GNU Compiler Compiler.
+ 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 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.
+ 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, 675 Mass Ave, Cambridge, MA 02139, USA. */
+ 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. */
-/* 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.
-
-The entry point is reader(). */
-
-#include <stdio.h>
-#include <ctype.h>
#include "system.h"
+#include "quotearg.h"
+#include "quote.h"
+#include "getargs.h"
#include "files.h"
-#include "alloc.h"
#include "symtab.h"
-#include "lex.h"
+#include "options.h"
#include "gram.h"
-#include "machine.h"
-
-#define LTYPESTR "\n#ifndef YYLTYPE\ntypedef\n struct yyltype\n\
- {\n int timestamp;\n int first_line;\n int first_column;\
-\n int last_line;\n int last_column;\n char *text;\n }\n\
- yyltype;\n\n#define YYLTYPE yyltype\n#endif\n\n"
-
-/* Number of slots allocated (but not necessarily used yet) in `rline' */
-int rline_allocated;
-
-extern char *program_name;
-extern int definesflag;
-extern int nolinesflag;
-extern int noparserflag;
-extern int rawtoknumflag;
-extern bucket *symval;
-extern int numval;
-extern int expected_conflicts;
-extern char *token_buffer;
-
-extern void init_lex();
-extern void tabinit();
-extern void output_headers();
-extern void output_trailers();
-extern void free_symtab();
-extern void open_extra_files();
-extern char *int_to_string();
-extern void fatal();
-extern void fatals();
-extern void warn();
-extern void warni();
-extern void warns();
-extern void warnss();
-extern void warnsss();
-extern void unlex();
-extern void done();
-
-extern int skip_white_space();
-extern int parse_percent_token();
-extern int lex();
-
-void reader_output_yylsp();
-void read_declarations();
-void copy_definition();
-void parse_token_decl();
-void parse_start_decl();
-void parse_type_decl();
-void parse_assoc_decl();
-void parse_union_decl();
-void parse_expect_decl();
-void parse_thong_decl();
-void copy_action();
-void readgram();
-void record_rule_line();
-void packsymbols();
-void output_token_defines();
-void packgram();
-int read_signed_integer();
-static int get_type();
-
-typedef
- struct symbol_list
- {
- struct symbol_list *next;
- bucket *sym;
- bucket *ruleprec;
- }
- symbol_list;
-
-
+#include "complain.h"
+#include "output.h"
+#include "reader.h"
+#include "conflicts.h"
+#include "muscle_tab.h"
int lineno;
-symbol_list *grammar;
-int start_flag;
-bucket *startval;
-char **tags;
-int *user_toknums;
-
-/* Nonzero if components of semantic values are used, implying
- they must be unions. */
-static int value_components_used;
-
-static int typed; /* nonzero if %union has been seen. */
-
-static int lastprec; /* incremented for each %left, %right or %nonassoc seen */
-
-static int gensym_count; /* incremented for each generated symbol */
+static symbol_list *grammar = NULL;
+static int start_flag = 0;
-static bucket *errtoken;
+/* Nonzero if %union has been seen. */
+int typed = 0;
-/* Nonzero if any action or guard uses the @n construct. */
-static int yylsp_needed;
-
-extern char *version_string;
-
-
-static void
-skip_to_char(target)
- int target;
+static symbol_list *
+symbol_list_new (symbol_t *sym)
{
- int c;
- if (target == '\n')
- warn(_(" Skipping to next \\n"));
- else
- warni(_(" Skipping to next %c"), target);
-
- do
- c = skip_white_space();
- while (c != target && c != EOF);
- if (c != EOF)
- ungetc(c, finput);
+ symbol_list *res = XMALLOC (symbol_list, 1);
+ res->next = NULL;
+ res->sym = sym;
+ res->line = lineno;
+ res->action = NULL;
+ res->action_line = 0;
+ res->ruleprec = NULL;
+ return res;
}
+\f
+/*--------------------------------------------------------------.
+| Get the data type (alternative in the union) of the value for |
+| symbol N in rule RULE. |
+`--------------------------------------------------------------*/
-void
-reader()
-{
- start_flag = 0;
- startval = NULL; /* start symbol not specified yet. */
-
-#if 0
- translations = 0; /* initially assume token number translation not needed. */
-#endif
- /* Nowadays translations is always set to 1,
- since we give `error' a user-token-number
- to satisfy the Posix demand for YYERRCODE==256. */
- translations = 1;
-
- nsyms = 1;
- nvars = 0;
- nrules = 0;
- nitems = 0;
- rline_allocated = 10;
- rline = NEW2(rline_allocated, short);
-
- typed = 0;
- lastprec = 0;
-
- gensym_count = 0;
-
- semantic_parser = 0;
- pure_parser = 0;
- yylsp_needed = 0;
-
- grammar = NULL;
-
- init_lex();
- lineno = 1;
-
- /* initialize the symbol table. */
- tabinit();
- /* construct the error token */
- errtoken = getsym("error");
- errtoken->class = STOKEN;
- errtoken->user_token_number = 256; /* Value specified by posix. */
- /* construct a token that represents all undefined literal tokens. */
- /* it is always token number 2. */
- getsym("$undefined.")->class = STOKEN;
- /* Read the declaration section. Copy %{ ... %} groups to ftable and fdefines file.
- Also notice any %token, %left, etc. found there. */
- if (noparserflag)
- fprintf(ftable, "\n/* Bison-generated parse tables, made from %s\n",
- infile);
- else
- fprintf(ftable, "\n/* A Bison parser, made from %s\n", infile);
- fprintf(ftable, " by %s */\n\n", version_string);
- fprintf(ftable, "#define YYBISON 1 /* Identify Bison output. */\n\n");
- read_declarations();
- /* start writing the guard and action files, if they are needed. */
- output_headers();
- /* read in the grammar, build grammar in list form. write out guards and actions. */
- readgram();
- /* Now we know whether we need the line-number stack.
- If we do, write its type into the .tab.h file. */
- if (fdefines)
- reader_output_yylsp(fdefines);
- /* write closing delimiters for actions and guards. */
- output_trailers();
- if (yylsp_needed)
- fprintf(ftable, "#define YYLSP_NEEDED\n\n");
- /* assign the symbols their symbol numbers.
- Write #defines for the token symbols into fdefines if requested. */
- packsymbols();
- /* convert the grammar into the format described in gram.h. */
- packgram();
- /* free the symbol table data structure
- since symbols are now all referred to by symbol number. */
- free_symtab();
-}
-
-void
-reader_output_yylsp(f)
- FILE *f;
-{
- if (yylsp_needed)
- fprintf(f, LTYPESTR);
-}
-
-/* read from finput until %% is seen. Discard the %%.
-Handle any % declarations,
-and copy the contents of any %{ ... %} groups to fattrs. */
-
-void
-read_declarations ()
+char *
+get_type_name (int n, symbol_list *rule)
{
- register int c;
- register int tok;
+ int i;
+ symbol_list *rp;
- for (;;)
+ if (n < 0)
{
- c = skip_white_space();
-
- if (c == '%')
- {
- tok = parse_percent_token();
-
- switch (tok)
- {
- case TWO_PERCENTS:
- return;
-
- case PERCENT_LEFT_CURLY:
- copy_definition();
- break;
-
- case TOKEN:
- parse_token_decl (STOKEN, SNTERM);
- break;
-
- case NTERM:
- parse_token_decl (SNTERM, STOKEN);
- break;
-
- case TYPE:
- parse_type_decl();
- break;
-
- case START:
- parse_start_decl();
- break;
-
- case UNION:
- parse_union_decl();
- break;
-
- case EXPECT:
- parse_expect_decl();
- break;
- case THONG:
- parse_thong_decl();
- break;
- case LEFT:
- parse_assoc_decl(LEFT_ASSOC);
- break;
-
- case RIGHT:
- parse_assoc_decl(RIGHT_ASSOC);
- break;
-
- case NONASSOC:
- parse_assoc_decl(NON_ASSOC);
- break;
-
- case SEMANTIC_PARSER:
- if (semantic_parser == 0)
- {
- semantic_parser = 1;
- open_extra_files();
- }
- break;
-
- case PURE_PARSER:
- pure_parser = 1;
- break;
-
- case NOOP:
- break;
-
- default:
- warns(_("unrecognized: %s"), token_buffer);
- skip_to_char('%');
- }
- }
- else if (c == EOF)
- fatal(_("no input grammar"));
- else
- {
- char buff[100];
- sprintf(buff, _("unknown character: %s"), printable_version(c));
- warn(buff);
- skip_to_char('%');
- }
+ complain (_("invalid $ value"));
+ return NULL;
}
-}
-
-
-/* copy the contents of a %{ ... %} into the definitions file.
-The %{ has already been read. Return after reading the %}. */
-
-void
-copy_definition ()
-{
- register int c;
- register int match;
- register int ended;
- register int after_percent; /* -1 while reading a character if prev char was % */
- int cplus_comment;
-
- if (!nolinesflag)
- fprintf(fattrs, "#line %d \"%s\"\n", lineno, infile);
- after_percent = 0;
-
- c = getc(finput);
+ rp = rule;
+ i = 0;
- for (;;)
+ while (i < n)
{
- switch (c)
- {
- case '\n':
- putc(c, fattrs);
- lineno++;
- break;
-
- case '%':
- after_percent = -1;
- break;
-
- case '\'':
- case '"':
- match = c;
- putc(c, fattrs);
- c = getc(finput);
-
- while (c != match)
- {
- if (c == EOF)
- fatal(_("unterminated string at end of file"));
- if (c == '\n')
- {
- warn(_("unterminated string"));
- ungetc(c, finput);
- c = match;
- continue;
- }
-
- putc(c, fattrs);
-
- if (c == '\\')
- {
- c = getc(finput);
- if (c == EOF)
- fatal(_("unterminated string at end of file"));
- putc(c, fattrs);
- if (c == '\n')
- lineno++;
- }
-
- c = getc(finput);
- }
-
- putc(c, fattrs);
- break;
-
- case '/':
- putc(c, fattrs);
- c = getc(finput);
- if (c != '*' && c != '/')
- continue;
-
- cplus_comment = (c == '/');
- putc(c, fattrs);
- c = getc(finput);
-
- ended = 0;
- while (!ended)
- {
- if (!cplus_comment && c == '*')
- {
- while (c == '*')
- {
- putc(c, fattrs);
- c = getc(finput);
- }
-
- if (c == '/')
- {
- putc(c, fattrs);
- ended = 1;
- }
- }
- else if (c == '\n')
- {
- lineno++;
- putc(c, fattrs);
- if (cplus_comment)
- ended = 1;
- else
- c = getc(finput);
- }
- else if (c == EOF)
- fatal(_("unterminated comment in `%{' definition"));
- else
- {
- putc(c, fattrs);
- c = getc(finput);
- }
- }
-
- break;
-
- case EOF:
- fatal(_("unterminated `%{' definition"));
-
- default:
- putc(c, fattrs);
- }
-
- c = getc(finput);
-
- if (after_percent)
+ rp = rp->next;
+ if (rp == NULL || rp->sym == NULL)
{
- if (c == '}')
- return;
- putc('%', fattrs);
+ complain (_("invalid $ value"));
+ return NULL;
}
- after_percent = 0;
-
+ ++i;
}
+ return rp->sym->type_name;
}
-
-/* parse what comes after %token or %nterm.
-For %token, what_is is STOKEN and what_is_not is SNTERM.
-For %nterm, the arguments are reversed. */
+/*-----------------------.
+| Set the start symbol. |
+`-----------------------*/
void
-parse_token_decl (what_is, what_is_not)
- int what_is, what_is_not;
+grammar_start_symbol_set (symbol_t *s)
{
- register int token = 0;
- register char *typename = 0;
- register struct bucket *symbol = NULL; /* pts to symbol being defined */
- int k;
-
- for (;;)
+ if (start_flag)
+ complain (_("multiple %s declarations"), "%start");
+ else
{
- if(ungetc(skip_white_space(), finput) == '%')
- return;
- token = lex();
- if (token == COMMA)
- {
- symbol = NULL;
- continue;
- }
- if (token == TYPENAME)
- {
- k = strlen(token_buffer);
- typename = NEW2(k + 1, char);
- strcpy(typename, token_buffer);
- value_components_used = 1;
- symbol = NULL;
- }
- else if (token == IDENTIFIER && *symval->tag == '\"'
- && symbol)
- {
- translations = 1;
- symval->class = STOKEN;
- symval->type_name = typename;
- symval->user_token_number = symbol->user_token_number;
- symbol->user_token_number = SALIAS;
-
- symval->alias = symbol;
- symbol->alias = symval;
- symbol = NULL;
-
- nsyms--; /* symbol and symval combined are only one symbol */
- }
- else if (token == IDENTIFIER)
- {
- int oldclass = symval->class;
- symbol = symval;
-
- if (symbol->class == what_is_not)
- warns(_("symbol %s redefined"), symbol->tag);
- symbol->class = what_is;
- if (what_is == SNTERM && oldclass != SNTERM)
- symbol->value = nvars++;
-
- if (typename)
- {
- if (symbol->type_name == NULL)
- symbol->type_name = typename;
- else if (strcmp(typename, symbol->type_name) != 0)
- warns(_("type redeclaration for %s"), symbol->tag);
- }
- }
- else if (symbol && token == NUMBER)
- {
- symbol->user_token_number = numval;
- translations = 1;
- }
- else
- {
- warnss(_("`%s' is invalid in %s"),
- token_buffer,
- (what_is == STOKEN) ? "%token" : "%nterm");
- skip_to_char('%');
- }
+ start_flag = 1;
+ startsymbol = s;
}
-
}
-/* 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
-*/
+/*----------------------------------------------------------------.
+| There are two prologues: one before %union, one after. Augment |
+| the current one. |
+`----------------------------------------------------------------*/
void
-parse_thong_decl ()
+prologue_augment (const char *prologue, int location)
{
- register int token;
- register struct bucket *symbol;
- register char *typename = 0;
- int k, usrtoknum;
-
- translations = 1;
- token = lex(); /* fetch typename or first token */
- if (token == TYPENAME) {
- k = strlen(token_buffer);
- typename = NEW2(k + 1, char);
- strcpy(typename, token_buffer);
- value_components_used = 1;
- token = lex(); /* fetch first token */
- }
-
- /* process first token */
-
- if (token != IDENTIFIER)
- {
- warns(_("unrecognized item %s, expected an identifier"),
- token_buffer);
- skip_to_char('%');
- return;
- }
- symval->class = STOKEN;
- symval->type_name = typename;
- symval->user_token_number = SALIAS;
- symbol = symval;
+ struct obstack *oout =
+ !typed ? &pre_prologue_obstack : &post_prologue_obstack;
- token = lex(); /* get number or literal string */
-
- if (token == NUMBER) {
- usrtoknum = numval;
- token = lex(); /* okay, did number, now get literal */
- }
- else usrtoknum = 0;
-
- /* process literal string token */
-
- if (token != IDENTIFIER || *symval->tag != '\"')
+ if (!no_lines_flag)
{
- warns(_("expected string constant instead of %s"),
- token_buffer);
- skip_to_char('%');
- return;
+ obstack_fgrow2 (oout, muscle_find ("linef"),
+ location, quotearg_style (c_quoting_style,
+ muscle_find ("filename")));
}
- symval->class = STOKEN;
- symval->type_name = typename;
- symval->user_token_number = usrtoknum;
-
- symval->alias = symbol;
- symbol->alias = symval;
-
- nsyms--; /* symbol and symval combined are only one symbol */
+ obstack_sgrow (oout, prologue);
}
-/* parse what comes after %start */
-
-void
-parse_start_decl ()
-{
- if (start_flag)
- warn(_("multiple %start declarations"));
- if (lex() != IDENTIFIER)
- warn(_("invalid %start declaration"));
- else
- {
- start_flag = 1;
- startval = symval;
- }
-}
-
-/* read in a %type declaration and record its information for get_type_name to access */
+/*----------------------.
+| Handle the epilogue. |
+`----------------------*/
void
-parse_type_decl ()
+epilogue_set (const char *epilogue, int location)
{
- register int k;
- register char *name;
-
- if (lex() != TYPENAME)
- {
- warn(_("%type declaration has no <typename>"));
- skip_to_char('%');
- return;
- }
-
- k = strlen(token_buffer);
- name = NEW2(k + 1, char);
- strcpy(name, token_buffer);
+ struct obstack el_obstack;
+ obstack_init (&el_obstack);
- for (;;)
+ if (!no_lines_flag)
{
- register int t;
-
- if(ungetc(skip_white_space(), finput) == '%')
- return;
-
- t = lex();
-
- switch (t)
- {
-
- case COMMA:
- case SEMICOLON:
- break;
-
- case IDENTIFIER:
- if (symval->type_name == NULL)
- symval->type_name = name;
- else if (strcmp(name, symval->type_name) != 0)
- warns(_("type redeclaration for %s"), symval->tag);
-
- break;
-
- default:
- warns(_("invalid %%type declaration due to item: `%s'"), token_buffer);
- skip_to_char('%');
- }
+ obstack_fgrow2 (&el_obstack, muscle_find ("linef"),
+ location, quotearg_style (c_quoting_style,
+ muscle_find ("filename")));
}
+ obstack_sgrow (&el_obstack, epilogue);
+ obstack_1grow (&el_obstack, 0);
+ muscle_insert ("epilogue", obstack_finish (&el_obstack));
}
+\f
-/* read in a %left, %right or %nonassoc declaration and record its information. */
-/* assoc is either LEFT_ASSOC, RIGHT_ASSOC or NON_ASSOC. */
+/*-------------------------------------------------------------------.
+| Generate a dummy symbol, a nonterminal, whose name cannot conflict |
+| with the user's names. |
+`-------------------------------------------------------------------*/
-void
-parse_assoc_decl (assoc)
-int assoc;
+static symbol_t *
+gensym (void)
{
- register int k;
- register char *name = NULL;
- register int prev = 0;
-
- lastprec++; /* Assign a new precedence level, never 0. */
-
- for (;;)
- {
- register int t;
-
- if(ungetc(skip_white_space(), finput) == '%')
- return;
-
- t = lex();
-
- switch (t)
- {
-
- case TYPENAME:
- k = strlen(token_buffer);
- name = NEW2(k + 1, char);
- strcpy(name, token_buffer);
- break;
-
- case COMMA:
- break;
-
- case IDENTIFIER:
- if (symval->prec != 0)
- warns(_("redefining precedence of %s"), symval->tag);
- symval->prec = lastprec;
- symval->assoc = assoc;
- if (symval->class == SNTERM)
- warns(_("symbol %s redefined"), symval->tag);
- symval->class = STOKEN;
- 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)
- warns(_("type redeclaration for %s"), symval->tag);
- }
- break;
-
- case NUMBER:
- if (prev == IDENTIFIER)
- {
- symval->user_token_number = numval;
- translations = 1;
- }
- else
- {
- warns(_("invalid text (%s) - number should be after identifier"),
- token_buffer);
- skip_to_char('%');
- }
- break;
-
- case SEMICOLON:
- return;
-
- default:
- warns(_("unexpected item: %s"), token_buffer);
- skip_to_char('%');
- }
+ /* Incremented for each generated symbol */
+ static int gensym_count = 0;
+ static char buf[256];
- prev = t;
+ symbol_t *sym;
- }
+ sprintf (buf, "@%d", ++gensym_count);
+ sym = getsym (buf);
+ sym->class = nterm_sym;
+ sym->number = nvars++;
+ return sym;
}
-
-
-
-/* copy the union declaration into fattrs (and fdefines),
- where it is made into the
- definition of YYSTYPE, the type of elements of the parser value stack. */
-
+\f
+/*-------------------------------------------------------------------.
+| 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 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 |
+| 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. |
+`-------------------------------------------------------------------*/
+
+/* The (currently) last symbol of GRAMMAR. */
+symbol_list *grammar_end = NULL;
+
+/* Append S to the GRAMMAR. */
void
-parse_union_decl()
+grammar_symbol_append (symbol_t *s)
{
- register int c;
- register int count;
- register int in_comment;
- int cplus_comment;
-
- if (typed)
- warn(_("multiple %union declarations"));
+ symbol_list *p = symbol_list_new (s);
- typed = 1;
-
- if (!nolinesflag)
- fprintf(fattrs, "\n#line %d \"%s\"\n", lineno, infile);
+ if (grammar_end)
+ grammar_end->next = p;
else
- fprintf(fattrs, "\n");
-
- fprintf(fattrs, "typedef union");
- if (fdefines)
- fprintf(fdefines, "typedef union");
+ grammar = p;
- count = 0;
- in_comment = 0;
-
- c = getc(finput);
-
- while (c != EOF)
- {
- putc(c, fattrs);
- if (fdefines)
- putc(c, fdefines);
+ grammar_end = p;
+}
- switch (c)
- {
- case '\n':
- lineno++;
- break;
-
- case '/':
- c = getc(finput);
- if (c != '*' && c != '/')
- ungetc(c, finput);
- else
- {
- putc(c, fattrs);
- if (fdefines)
- putc(c, fdefines);
- cplus_comment = (c == '/');
- in_comment = 1;
- c = getc(finput);
- while (in_comment)
- {
- putc(c, fattrs);
- if (fdefines)
- putc(c, fdefines);
-
- if (c == '\n')
- {
- lineno++;
- if (cplus_comment)
- {
- in_comment = 0;
- break;
- }
- }
- if (c == EOF)
- fatal(_("unterminated comment at end of file"));
-
- if (!cplus_comment && c == '*')
- {
- c = getc(finput);
- if (c == '/')
- {
- putc('/', fattrs);
- if (fdefines)
- putc('/', fdefines);
- in_comment = 0;
- }
- }
- else
- c = getc(finput);
- }
- }
- break;
-
-
- case '{':
- count++;
- break;
-
- case '}':
- if (count == 0)
- warn (_("unmatched close-brace (`}')"));
- count--;
- if (count <= 0)
- {
- fprintf(fattrs, " YYSTYPE;\n");
- if (fdefines)
- fprintf(fdefines, " YYSTYPE;\n");
- /* JF don't choke on trailing semi */
- c=skip_white_space();
- if(c!=';') ungetc(c,finput);
- return;
- }
- }
+/* The rule currently being defined, and the previous rule. Point to
+ the first symbol of each list: their lhs. */
+symbol_list *current_rule = NULL;
+symbol_list *previous_rule = NULL;
- c = getc(finput);
- }
-}
-/* parse the declaration %expect N which says to expect N
- shift-reduce conflicts. */
+/* Create a new rule for LHS in to the GRAMMAR. */
void
-parse_expect_decl()
+grammar_rule_begin (symbol_t *lhs)
{
- register int c;
- register int count;
- char buffer[20];
-
- c = getc(finput);
- while (c == ' ' || c == '\t')
- c = getc(finput);
-
- count = 0;
- while (c >= '0' && c <= '9')
+ if (!start_flag)
{
- if (count < 20)
- buffer[count++] = c;
- c = getc(finput);
+ startsymbol = lhs;
+ start_flag = 1;
}
- buffer[count] = 0;
- ungetc (c, finput);
+ /* Start a new rule and record its lhs. */
+ ++nrules;
+ ++nritems;
- if (count <= 0 || count > 10)
- warn(_("argument of %expect is not an integer"));
- expected_conflicts = atoi (buffer);
-}
+ previous_rule = grammar_end;
+ grammar_symbol_append (lhs);
+ current_rule = grammar_end;
-/* that's all of parsing the declaration section */
-\f
-/* Get the data type (alternative in the union) of the value for symbol n in rule rule. */
+ /* Mark the rule's lhs as a nonterminal if not already so. */
-char *
-get_type_name(n, rule)
-int n;
-symbol_list *rule;
-{
- static char *msg = N_("invalid $ value");
-
- register int i;
- register symbol_list *rp;
-
- if (n < 0)
+ if (lhs->class == unknown_sym)
{
- warn(_(msg));
- return NULL;
+ lhs->class = nterm_sym;
+ lhs->number = nvars;
+ ++nvars;
}
-
- rp = rule;
- i = 0;
-
- while (i < n)
- {
- rp = rp->next;
- if (rp == NULL || rp->sym == NULL)
- {
- warn(_(msg));
- return NULL;
- }
- i++;
- }
-
- return (rp->sym->type_name);
+ else if (lhs->class == token_sym)
+ complain (_("rule given for %s, which is a token"), lhs->tag);
}
+/* Check that the last rule (CURRENT_RULE) is properly defined. For
+ instance, there should be no type clash on the default action. */
-/* after %guard is seen in the input file,
-copy the actual guard into the guards file.
-If the guard is followed by an action, copy that 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,
-for the simple parser in which the stack is not popped until after the guard is run. */
-
-void
-copy_guard(rule, stack_offset)
-symbol_list *rule;
-int stack_offset;
+static void
+grammar_current_rule_check (void)
{
- register int c;
- register int n;
- register int count;
- register int match;
- register int ended;
- register char *type_name;
- int brace_flag = 0;
- int cplus_comment;
-
- /* offset is always 0 if parser has already popped the stack pointer */
- if (semantic_parser) stack_offset = 0;
-
- fprintf(fguard, "\ncase %d:\n", nrules);
- if (!nolinesflag)
- fprintf(fguard, "#line %d \"%s\"\n", lineno, infile);
- putc('{', fguard);
-
- count = 0;
- c = getc(finput);
-
- while (brace_flag ? (count > 0) : (c != ';'))
- {
- switch (c)
- {
- case '\n':
- putc(c, fguard);
- lineno++;
- break;
-
- case '{':
- putc(c, fguard);
- brace_flag = 1;
- count++;
- break;
-
- case '}':
- putc(c, fguard);
- if (count > 0)
- count--;
- else
- {
- warn(_("unmatched right brace (`}')"));
- c = getc(finput); /* skip it */
- }
- break;
-
- case '\'':
- case '"':
- match = c;
- putc(c, fguard);
- c = getc(finput);
-
- while (c != match)
- {
- if (c == EOF)
- fatal(_("unterminated string at end of file"));
- if (c == '\n')
- {
- warn(_("unterminated string"));
- ungetc(c, finput);
- c = match; /* invent terminator */
- continue;
- }
-
- putc(c, fguard);
-
- if (c == '\\')
- {
- c = getc(finput);
- if (c == EOF)
- fatal(_("unterminated string"));
- putc(c, fguard);
- if (c == '\n')
- lineno++;
- }
-
- c = getc(finput);
- }
-
- putc(c, fguard);
- break;
-
- case '/':
- putc(c, fguard);
- c = getc(finput);
- if (c != '*' && c != '/')
- continue;
-
- cplus_comment = (c == '/');
- putc(c, fguard);
- c = getc(finput);
-
- ended = 0;
- while (!ended)
- {
- if (!cplus_comment && c == '*')
- {
- while (c == '*')
- {
- putc(c, fguard);
- c = getc(finput);
- }
-
- if (c == '/')
- {
- putc(c, fguard);
- ended = 1;
- }
- }
- else if (c == '\n')
- {
- lineno++;
- putc(c, fguard);
- if (cplus_comment)
- ended = 1;
- else
- c = getc(finput);
- }
- else if (c == EOF)
- fatal(_("unterminated comment"));
- else
- {
- putc(c, fguard);
- c = getc(finput);
- }
- }
-
- break;
-
- case '$':
- c = getc(finput);
- type_name = NULL;
-
- if (c == '<')
- {
- register char *cp = token_buffer;
-
- while ((c = getc(finput)) != '>' && c > 0)
- *cp++ = c;
- *cp = 0;
- type_name = token_buffer;
-
- c = getc(finput);
- }
-
- if (c == '$')
- {
- fprintf(fguard, "yyval");
- if (!type_name) type_name = rule->sym->type_name;
- if (type_name)
- fprintf(fguard, ".%s", type_name);
- if(!type_name && typed)
- warns(_("$$ of `%s' has no declared type"), rule->sym->tag);
- }
-
- else if (isdigit(c) || c == '-')
- {
- ungetc (c, finput);
- n = read_signed_integer(finput);
- c = getc(finput);
-
- if (!type_name && n > 0)
- type_name = get_type_name(n, rule);
-
- fprintf(fguard, "yyvsp[%d]", n - stack_offset);
- if (type_name)
- fprintf(fguard, ".%s", type_name);
- if(!type_name && typed)
- warnss(_("$%s of `%s' has no declared type"), int_to_string(n), rule->sym->tag);
- continue;
- }
- else
- warni(_("$%s is invalid"), printable_version(c));
-
- break;
-
- case '@':
- c = getc(finput);
- if (isdigit(c) || c == '-')
- {
- ungetc (c, finput);
- n = read_signed_integer(finput);
- c = getc(finput);
- }
- else
- {
- warni(_("@%s is invalid"), printable_version(c));
- n = 1;
- }
-
- fprintf(fguard, "yylsp[%d]", n - stack_offset);
- yylsp_needed = 1;
-
- continue;
-
- case EOF:
- fatal(_("unterminated %%guard clause"));
-
- default:
- putc(c, fguard);
- }
+ symbol_t *lhs = current_rule->sym;
+ symbol_t *first_rhs = current_rule->next->sym;
- if (c != '}' || count != 0)
- c = getc(finput);
- }
+ /* If there is an action, then there is nothing we can do: the user
+ is allowed to shoot in her foot. */
+ if (current_rule->action)
+ return;
- c = skip_white_space();
-
- fprintf(fguard, ";\n break;}");
- if (c == '{')
- copy_action(rule, stack_offset);
- else if (c == '=')
+ /* If $$ is being set in default way, report if any type mismatch.
+ */
+ if (first_rhs)
{
- c = getc(finput); /* why not skip_white_space -wjh */
- if (c == '{')
- copy_action(rule, stack_offset);
+ const char *lhs_type = lhs->type_name ? lhs->type_name : "";
+ const char *rhs_type = first_rhs->type_name ? first_rhs->type_name : "";
+ if (strcmp (lhs_type, rhs_type))
+ complain (_("type clash (`%s' `%s') on default action"),
+ lhs_type, rhs_type);
}
+ /* Warn if there is no default for $$ but we need one. */
else
- ungetc(c, finput);
-}
-
-
-
-/* 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. */
-
-void
-copy_action(rule, stack_offset)
-symbol_list *rule;
-int stack_offset;
-{
- register int c;
- register int n;
- register int count;
- register int match;
- register int ended;
- register char *type_name;
- int cplus_comment;
-
- /* offset is always 0 if parser has already popped the stack pointer */
- if (semantic_parser) stack_offset = 0;
-
- fprintf(faction, "\ncase %d:\n", nrules);
- if (!nolinesflag)
- fprintf(faction, "#line %d \"%s\"\n", lineno, infile);
- putc('{', faction);
-
- count = 1;
- c = getc(finput);
-
- while (count > 0)
{
- while (c != '}')
- {
- switch (c)
- {
- case '\n':
- putc(c, faction);
- lineno++;
- break;
-
- case '{':
- putc(c, faction);
- count++;
- break;
-
- case '\'':
- case '"':
- match = c;
- putc(c, faction);
- c = getc(finput);
-
- while (c != match)
- {
- if (c == '\n')
- {
- warn(_("unterminated string"));
- ungetc(c, finput);
- c = match;
- continue;
- }
- else if (c == EOF)
- fatal(_("unterminated string at end of file"));
-
- putc(c, faction);
-
- if (c == '\\')
- {
- c = getc(finput);
- if (c == EOF)
- fatal(_("unterminated string"));
- putc(c, faction);
- if (c == '\n')
- lineno++;
- }
-
- c = getc(finput);
- }
-
- putc(c, faction);
- break;
-
- case '/':
- putc(c, faction);
- c = getc(finput);
- if (c != '*' && c != '/')
- continue;
-
- cplus_comment = (c == '/');
- putc(c, faction);
- c = getc(finput);
-
- ended = 0;
- while (!ended)
- {
- if (!cplus_comment && c == '*')
- {
- while (c == '*')
- {
- putc(c, faction);
- c = getc(finput);
- }
-
- if (c == '/')
- {
- putc(c, faction);
- ended = 1;
- }
- }
- else if (c == '\n')
- {
- lineno++;
- putc(c, faction);
- if (cplus_comment)
- ended = 1;
- else
- c = getc(finput);
- }
- else if (c == EOF)
- fatal(_("unterminated comment"));
- else
- {
- putc(c, faction);
- c = getc(finput);
- }
- }
-
- break;
-
- case '$':
- c = getc(finput);
- type_name = NULL;
-
- if (c == '<')
- {
- register char *cp = token_buffer;
-
- while ((c = getc(finput)) != '>' && c > 0)
- *cp++ = c;
- *cp = 0;
- type_name = token_buffer;
- value_components_used = 1;
-
- c = getc(finput);
- }
- if (c == '$')
- {
- fprintf(faction, "yyval");
- if (!type_name) type_name = get_type_name(0, rule);
- if (type_name)
- fprintf(faction, ".%s", type_name);
- if(!type_name && typed)
- warns(_("$$ of `%s' has no declared type"), rule->sym->tag);
- }
- else if (isdigit(c) || c == '-')
- {
- ungetc (c, finput);
- n = read_signed_integer(finput);
- c = getc(finput);
-
- if (!type_name && n > 0)
- type_name = get_type_name(n, rule);
-
- fprintf(faction, "yyvsp[%d]", n - stack_offset);
- if (type_name)
- fprintf(faction, ".%s", type_name);
- if(!type_name && typed)
- warnss(_("$%s of `%s' has no declared type"),
- int_to_string(n), rule->sym->tag);
- continue;
- }
- else
- warni(_("$%s is invalid"), printable_version(c));
-
- break;
-
- case '@':
- c = getc(finput);
- if (isdigit(c) || c == '-')
- {
- ungetc (c, finput);
- n = read_signed_integer(finput);
- c = getc(finput);
- }
- else
- {
- warn(_("invalid @-construct"));
- n = 1;
- }
-
- fprintf(faction, "yylsp[%d]", n - stack_offset);
- yylsp_needed = 1;
-
- continue;
-
- case EOF:
- fatal(_("unmatched `{'"));
-
- default:
- putc(c, faction);
- }
-
- c = getc(finput);
- }
-
- /* above loop exits when c is '}' */
-
- if (--count)
- {
- putc(c, faction);
- c = getc(finput);
- }
+ if (lhs->type_name)
+ complain (_("empty rule for typed nonterminal, and no action"));
}
-
- fprintf(faction, ";\n break;}");
}
+/* End the currently being grown rule. */
-/* generate a dummy symbol, a nonterminal,
-whose name cannot conflict with the user's names. */
-
-bucket *
-gensym()
+void
+grammar_rule_end (void)
{
- register bucket *sym;
-
- sprintf (token_buffer, "@%d", ++gensym_count);
- sym = getsym(token_buffer);
- sym->class = SNTERM;
- sym->value = nvars++;
- return (sym);
+ /* Put an empty link in the list to mark the end of this rule */
+ grammar_symbol_append (NULL);
+ grammar_current_rule_check ();
}
-/* 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. */
+/* The previous action turns out the be a mid-rule action. Attach it
+ to the current rule, i.e., create a dummy symbol, attach it this
+ mid-rule action, and append this dummy nonterminal to the current
+ rule. */
void
-readgram()
+grammar_midrule_action (void)
{
- register int t;
- register bucket *lhs;
- register symbol_list *p;
- register symbol_list *p1;
- register bucket *bp;
-
- symbol_list *crule; /* points to first symbol_list of current rule. */
- /* its symbol is the lhs of the rule. */
- symbol_list *crule1; /* points to the symbol_list preceding crule. */
-
- p1 = NULL;
-
- t = lex();
-
- while (t != TWO_PERCENTS && t != ENDFILE)
- {
- if (t == IDENTIFIER || t == BAR)
- {
- register int actionflag = 0;
- int rulelength = 0; /* number of symbols in rhs of this rule so far */
- int xactions = 0; /* JF for error checking */
- bucket *first_rhs = 0;
-
- if (t == IDENTIFIER)
- {
- lhs = symval;
-
- if (!start_flag)
- {
- startval = lhs;
- start_flag = 1;
- }
-
- t = lex();
- if (t != COLON)
- {
- warn(_("ill-formed rule: initial symbol not followed by colon"));
- unlex(t);
- }
- }
-
- if (nrules == 0 && t == BAR)
- {
- warn(_("grammar starts with vertical bar"));
- lhs = symval; /* BOGUS: use a random symval */
- }
- /* start a new rule and record its lhs. */
-
- nrules++;
- nitems++;
-
- record_rule_line ();
-
- p = NEW(symbol_list);
- p->sym = 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 == SUNKNOWN)
- {
- lhs->class = SNTERM;
- lhs->value = nvars;
- nvars++;
- }
- else if (lhs->class == STOKEN)
- warns(_("rule given for %s, which is a token"), lhs->tag);
-
- /* read the rhs of the rule. */
-
- for (;;)
- {
- t = lex();
- if (t == PREC)
- {
- t = lex();
- crule->ruleprec = symval;
- t = lex();
- }
-
- if (! (t == IDENTIFIER || t == LEFT_CURLY)) break;
-
- /* If next token is an identifier, see if a colon follows it.
- If one does, exit this rule now. */
- if (t == IDENTIFIER)
- {
- register bucket *ssave;
- register int t1;
-
- ssave = symval;
- t1 = lex();
- unlex(t1);
- symval = ssave;
- if (t1 == 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 (actionflag)
- {
- register bucket *sdummy;
-
- /* 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. */
- 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++;
- record_rule_line ();
- p = NEW(symbol_list);
- if (crule1)
- crule1->next = p;
- else grammar = p;
- p->sym = sdummy;
- crule1 = NEW(symbol_list);
- p->next = crule1;
- crule1->next = crule;
-
- /* insert the dummy generated by that rule into this rule. */
- nitems++;
- p = NEW(symbol_list);
- p->sym = sdummy;
- p1->next = p;
- p1 = p;
-
- actionflag = 0;
- }
-
- if (t == IDENTIFIER)
- {
- nitems++;
- p = NEW(symbol_list);
- p->sym = symval;
- p1->next = p;
- p1 = p;
- }
- else /* handle an action. */
- {
- copy_action(crule, rulelength);
- actionflag = 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 = NEW(symbol_list);
- p1->next = p;
- p1 = p;
-
- if (t == PREC)
- {
- warn(_("two @prec's in a row"));
- t = lex();
- crule->ruleprec = symval;
- t = lex();
- }
- if (t == GUARD)
- {
- if (! semantic_parser)
- warn(_("%%guard present but %%semantic_parser not specified"));
-
- copy_guard(crule, rulelength);
- t = lex();
- }
- else if (t == LEFT_CURLY)
- {
- /* This case never occurs -wjh */
- if (actionflag) warn(_("two actions at end of one rule"));
- copy_action(crule, rulelength);
- actionflag = 1;
- xactions++; /* -wjh */
- t = lex();
- }
- /* If $$ is being set in default way,
- warn if any type mismatch. */
- else if (!xactions && first_rhs && lhs->type_name != first_rhs->type_name)
- {
- if (lhs->type_name == 0 || first_rhs->type_name == 0
- || strcmp(lhs->type_name,first_rhs->type_name))
- warnss(_("type clash (`%s' `%s') on default action"),
- lhs->type_name ? lhs->type_name : "",
- first_rhs->type_name ? first_rhs->type_name : "");
- }
- /* Warn if there is no default for $$ but we need one. */
- else if (!xactions && !first_rhs && lhs->type_name != 0)
- warn(_("empty rule for typed nonterminal, and no action"));
- if (t == SEMICOLON)
- t = lex();
- }
-#if 0
- /* these things can appear as alternatives to rules. */
-/* NO, they cannot.
- a) none of the documentation allows them
- b) most of them scan forward until finding a next %
- thus they may swallow lots of intervening rules
-*/
- else if (t == TOKEN)
- {
- parse_token_decl(STOKEN, SNTERM);
- t = lex();
- }
- else if (t == NTERM)
- {
- parse_token_decl(SNTERM, STOKEN);
- t = lex();
- }
- else if (t == TYPE)
- {
- t = get_type();
- }
- else if (t == UNION)
- {
- parse_union_decl();
- t = lex();
- }
- else if (t == EXPECT)
- {
- parse_expect_decl();
- t = lex();
- }
- else if (t == START)
- {
- parse_start_decl();
- t = lex();
- }
-#endif
-
- else
- {
- warns(_("invalid input: %s"), token_buffer);
- t = lex();
- }
- }
-
- /* grammar has been read. Do some checking */
-
- if (nsyms > MAXSHORT)
- fatals(_("too many symbols (tokens plus nonterminals); maximum %s"),
- int_to_string(MAXSHORT));
- if (nrules == 0)
- fatal(_("no rules in the input grammar"));
-
- if (typed == 0 /* JF put out same default YYSTYPE as YACC does */
- && !value_components_used)
- {
- /* We used to use `unsigned long' as YYSTYPE on MSDOS,
- but it seems better to be consistent.
- Most programs should declare their own type anyway. */
- fprintf(fattrs, "#ifndef YYSTYPE\n#define YYSTYPE int\n#endif\n");
- if (fdefines)
- fprintf(fdefines, "#ifndef YYSTYPE\n#define YYSTYPE int\n#endif\n");
- }
+ /* 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. */
+ symbol_t *sdummy = gensym ();
+ symbol_list *midrule_action = symbol_list_new (sdummy);
+
+ /* Make a new rule, whose body is empty, before the current one, so
+ that the action just read can belong to it. */
+ ++nrules;
+ ++nritems;
+ /* Attach its lineno to that of the host rule. */
+ midrule_action->line = current_rule->line;
+ /* Move the action from the host rule to this one. */
+ midrule_action->action = current_rule->action;
+ midrule_action->action_line = current_rule->action_line;
+ current_rule->action = NULL;
+
+ if (previous_rule)
+ previous_rule->next = midrule_action;
+ else
+ grammar = midrule_action;
- /* Report any undefined symbols and consider them nonterminals. */
+ /* End of the rule. */
+ previous_rule = symbol_list_new (NULL);
+ previous_rule->next = current_rule;
- for (bp = firstsymbol; bp; bp = bp->next)
- if (bp->class == SUNKNOWN)
- {
- warns(_("symbol %s is used, but is not defined as a token and has no rules"),
- bp->tag);
- bp->class = SNTERM;
- bp->value = nvars++;
- }
+ midrule_action->next = previous_rule;
- ntokens = nsyms - nvars;
+ /* Insert the dummy generated by that rule into this rule. */
+ ++nritems;
+ grammar_symbol_append (sdummy);
}
+/* Set the precedence symbol of the current rule to PRECSYM. */
void
-record_rule_line ()
+grammar_current_rule_prec_set (symbol_t *precsym)
{
- /* Record each rule's source line number in rline table. */
-
- if (nrules >= rline_allocated)
- {
- rline_allocated = nrules * 2;
- rline = (short *) xrealloc (rline,
- rline_allocated * sizeof (short));
- }
- rline[nrules] = lineno;
+ if (current_rule->ruleprec)
+ complain (_("two @prec's in a row"));
+ current_rule->ruleprec = precsym;
}
+/* Attach a SYMBOL to the current rule. If needed, move the previous
+ action as a mid-rule action. */
-/* read in a %type declaration and record its information for get_type_name to access */
-/* this is unused. it is only called from the #if 0 part of readgram */
-static int
-get_type()
+void
+grammar_current_rule_symbol_append (symbol_t *symbol)
{
- register int k;
- register int t;
- register char *name;
-
- t = lex();
-
- if (t != TYPENAME)
- {
- warn(_("ill-formed %type declaration"));
- return t;
- }
-
- k = strlen(token_buffer);
- name = NEW2(k + 1, char);
- strcpy(name, token_buffer);
-
- for (;;)
- {
- t = lex();
-
- switch (t)
- {
- case SEMICOLON:
- return (lex());
-
- case COMMA:
- break;
-
- case IDENTIFIER:
- if (symval->type_name == NULL)
- symval->type_name = name;
- else if (strcmp(name, symval->type_name) != 0)
- warns(_("type redeclaration for %s"), symval->tag);
-
- break;
-
- default:
- return (t);
- }
- }
+ if (current_rule->action)
+ grammar_midrule_action ();
+ ++nritems;
+ grammar_symbol_append (symbol);
}
-
-/* assign symbol numbers, and write definition of token names into fdefines.
-Set up vectors tags and sprec of names and precedences of symbols. */
+/* Attach an ACTION to the current rule. If needed, move the previous
+ action as a mid-rule action. */
void
-packsymbols()
+grammar_current_rule_action_append (const char *action, int action_line)
{
- register bucket *bp;
- register int tokno = 1;
- register int i;
- register int last_user_token_number;
+ if (current_rule->action)
+ grammar_midrule_action ();
+ current_rule->action = action;
+ current_rule->action_line = action_line;
+}
- /* int lossage = 0; JF set but not used */
+\f
+/*---------------------------------------------------------------.
+| Convert the rules into the representation using RRHS, RLHS and |
+| RITEM. |
+`---------------------------------------------------------------*/
- tags = NEW2(nsyms + 1, char *);
- tags[0] = "$";
- user_toknums = NEW2(nsyms + 1, int);
- user_toknums[0] = 0;
+static void
+packgram (void)
+{
+ unsigned int itemno;
+ int ruleno;
+ symbol_list *p;
- sprec = NEW2(nsyms, short);
- sassoc = NEW2(nsyms, short);
+ ritem = XCALLOC (item_number_t, nritems);
+ rules = XCALLOC (rule_t, nrules) - 1;
- max_user_token_number = 256;
- last_user_token_number = 256;
+ itemno = 0;
+ ruleno = 1;
- for (bp = firstsymbol; bp; bp = bp->next)
+ p = grammar;
+ while (p)
{
- if (bp->class == SNTERM)
- {
- 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 == 0)
- 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)
- warnss(_("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)
- warnss(_("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;
- }
-
- if (bp->user_token_number == SALIAS)
- continue; /* do not do processing below for SALIASs */
-
- }
- else /* bp->class == STOKEN */
+ symbol_t *ruleprec = p->ruleprec;
+ rules[ruleno].user_number = ruleno;
+ rules[ruleno].number = ruleno;
+ rules[ruleno].lhs = p->sym;
+ rules[ruleno].rhs = ritem + itemno;
+ rules[ruleno].line = p->line;
+ rules[ruleno].useful = TRUE;
+ rules[ruleno].action = p->action;
+ rules[ruleno].action_line = p->action_line;
+
+ p = p->next;
+ while (p && p->sym)
{
- bp->value = tokno++;
+ /* item_number_t = symbol_number_t.
+ But the former needs to contain more: negative rule numbers. */
+ ritem[itemno++] = symbol_number_as_item_number (p->sym->number);
+ /* A rule gets by default the precedence and associativity
+ of the last token in it. */
+ if (p->sym->class == token_sym)
+ rules[ruleno].prec = p->sym;
+ if (p)
+ p = p->next;
}
- if (bp->class == STOKEN)
+ /* If this rule has a %prec,
+ the specified symbol's precedence replaces the default. */
+ if (ruleprec)
{
- if (translations && !(bp->user_token_number))
- 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;
+ rules[ruleno].precsym = ruleprec;
+ rules[ruleno].prec = ruleprec;
}
+ ritem[itemno++] = -ruleno;
+ ++ruleno;
- tags[bp->value] = bp->tag;
- user_toknums[bp->value] = bp->user_token_number;
- sprec[bp->value] = bp->prec;
- sassoc[bp->value] = bp->assoc;
-
+ if (p)
+ p = p->next;
}
- if (translations)
- {
- register int i;
-
- token_translations = NEW2(max_user_token_number+1, short);
-
- /* 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)
- {
- if (bp->value >= ntokens) continue; /* non-terminal */
- if (bp->user_token_number == SALIAS) continue;
- if (token_translations[bp->user_token_number] != 2)
- warnsss(_("tokens %s and %s both assigned number %s"),
- tags[token_translations[bp->user_token_number]],
- bp->tag,
- int_to_string(bp->user_token_number));
- token_translations[bp->user_token_number] = bp->value;
- }
- }
-
- error_token_number = errtoken->value;
-
- if (! noparserflag)
- output_token_defines(ftable);
+ assert (itemno == nritems);
- if (startval->class == SUNKNOWN)
- fatals(_("the start symbol %s is undefined"), startval->tag);
- else if (startval->class == STOKEN)
- fatals(_("the start symbol %s is a token"), startval->tag);
-
- start_symbol = startval->value;
-
- if (definesflag)
- {
- output_token_defines(fdefines);
-
- if (!pure_parser)
- {
- if (spec_name_prefix)
- fprintf(fdefines, "\nextern YYSTYPE %slval;\n", spec_name_prefix);
- else
- fprintf(fdefines, "\nextern YYSTYPE yylval;\n");
- }
-
- if (semantic_parser)
- for (i = ntokens; i < nsyms; i++)
- {
- /* don't make these for dummy nonterminals made by gensym. */
- if (*tags[i] != '@')
- fprintf(fdefines, "#define\tNT%s\t%d\n", tags[i], i);
- }
-#if 0
- /* `fdefines' is now a temporary file, so we need to copy its
- contents in `done', so we can't close it here. */
- fclose(fdefines);
- fdefines = NULL;
-#endif
- }
+ if (trace_flag)
+ ritem_print (stderr);
}
+\f
+/*------------------------------------------------------------------.
+| 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. |
+`------------------------------------------------------------------*/
-/* For named tokens, but not literal ones, define the name.
- The value is the user token number.
-*/
void
-output_token_defines(file)
-FILE *file;
+reader (void)
{
- bucket *bp;
- register char *cp, *symbol;
- register char c;
-
- for (bp = firstsymbol; bp; bp = bp->next)
- {
- symbol = bp->tag; /* get symbol */
+ gram_control_t gram_control;
+ lineno = 1;
- 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;
- }
+ /* Initialize the muscle obstack. */
+ obstack_init (&muscle_obstack);
- /* Don't #define nonliteral tokens whose names contain periods. */
- cp = symbol;
- while ((c = *cp++) && c != '.');
- if (c != '\0') continue;
-
- fprintf(file, "#define\t%s\t%d\n", symbol,
- ((translations && ! rawtoknumflag)
- ? bp->user_token_number
- : bp->value));
- if (semantic_parser)
- fprintf(file, "#define\tT%s\t%d\n", symbol, bp->value);
- }
+ /* Initialize the symbol table. */
+ symbols_new ();
- putc('\n', file);
-}
+ /* Construct the axiom symbol. */
+ axiom = getsym ("$axiom");
+ axiom->class = nterm_sym;
+ axiom->number = nvars++;
+ /* Construct the error token */
+ errtoken = getsym ("error");
+ errtoken->class = token_sym;
+ errtoken->number = ntokens++;
+ /* Construct a token that represents all undefined literal tokens.
+ It is always token number 2. */
+ undeftoken = getsym ("$undefined.");
+ undeftoken->class = token_sym;
+ undeftoken->number = ntokens++;
-/* convert the rules into the representation using rrhs, rlhs and ritems. */
+ /* Initialize the obstacks. */
+ obstack_init (&action_obstack);
+ obstack_init (&output_obstack);
+ obstack_init (&pre_prologue_obstack);
+ obstack_init (&post_prologue_obstack);
-void
-packgram()
-{
- register int itemno;
- register int ruleno;
- register symbol_list *p;
-/* register bucket *bp; JF unused */
+ finput = xfopen (infile, "r");
+ gram_in = finput;
- bucket *ruleprec;
+ gram_debug = !!getenv ("parse");
+ gram__flex_debug = !!getenv ("scan");
+ gram_parse (&gram_control);
- ritem = NEW2(nitems + 1, short);
- rlhs = NEW2(nrules, short) - 1;
- rrhs = NEW2(nrules, short) - 1;
- rprec = NEW2(nrules, short) - 1;
- rprecsym = NEW2(nrules, short) - 1;
- rassoc = NEW2(nrules, short) - 1;
+ /* Grammar has been read. Do some checking */
+ if (nrules == 0)
+ fatal (_("no rules in the input grammar"));
- itemno = 0;
- ruleno = 1;
+ /* Report any undefined symbols and consider them nonterminals. */
+ symbols_check_defined ();
- p = grammar;
- while (p)
+ /* If the user did not define her EOFTOKEN, do it now. */
+ if (!eoftoken)
{
- rlhs[ruleno] = p->sym->value;
- rrhs[ruleno] = itemno;
- ruleprec = p->ruleprec;
-
- p = p->next;
- while (p && p->sym)
- {
- ritem[itemno++] = p->sym->value;
- /* A rule gets by default the precedence and associativity
- of the last token in it. */
- if (p->sym->class == STOKEN)
- {
- rprec[ruleno] = p->sym->prec;
- rassoc[ruleno] = p->sym->assoc;
- }
- if (p) p = p->next;
- }
-
- /* If this rule has a %prec,
- the specified symbol's precedence replaces the default. */
- if (ruleprec)
- {
- rprec[ruleno] = ruleprec->prec;
- rassoc[ruleno] = ruleprec->assoc;
- rprecsym[ruleno] = ruleprec->value;
- }
+ eoftoken = getsym ("$");
+ eoftoken->class = token_sym;
+ eoftoken->number = 0;
+ /* Value specified by POSIX. */
+ eoftoken->user_token_number = 0;
+ }
- ritem[itemno++] = -ruleno;
- ruleno++;
+ /* Insert the initial rule, which line is that of the first rule
+ (not that of the start symbol):
+
+ axiom: %start EOF. */
+ {
+ symbol_list *p = symbol_list_new (axiom);
+ p->line = grammar->line;
+ p->next = symbol_list_new (startsymbol);
+ p->next->next = symbol_list_new (eoftoken);
+ p->next->next->next = symbol_list_new (NULL);
+ p->next->next->next->next = grammar;
+ nrules += 1;
+ nritems += 3;
+ grammar = p;
+ }
- if (p) p = p->next;
- }
+ if (nsyms > SHRT_MAX)
+ fatal (_("too many symbols (tokens plus nonterminals); maximum %d"),
+ SHRT_MAX);
- ritem[itemno] = 0;
-}
-\f
-/* Read a signed integer from STREAM and return its value. */
+ assert (nsyms == ntokens + nvars);
-int
-read_signed_integer (stream)
- FILE *stream;
-{
- register int c = getc(stream);
- register int sign = 1;
- register int n;
+ xfclose (finput);
- if (c == '-')
- {
- c = getc(stream);
- sign = -1;
- }
- n = 0;
- while (isdigit(c))
- {
- n = 10*n + (c - '0');
- c = getc(stream);
- }
+ /* Assign the symbols their symbol numbers. Write #defines for the
+ token symbols into FDEFINES if requested. */
+ symbols_pack ();
- ungetc(c, stream);
+ /* Convert the grammar into the format described in gram.h. */
+ packgram ();
- return n * sign;
+ /* The grammar as a symbol_list is no longer needed. */
+ LIST_FREE (symbol_list, grammar);
}
projects / bison.git / blobdiff