X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/9a1af7e6b2ba4581b98f18a64db7431fcd8d5b52..55f0c7b1f26afabb7f356343f2650626e09fce51:/src/reader.c diff --git a/src/reader.c b/src/reader.c index 3f7cb0e3..6b247b7f 100644 --- a/src/reader.c +++ b/src/reader.c @@ -1,1839 +1,537 @@ -/* Input parser for bison - Copyright (C) 1984, 1986, 1989 Free Software Foundation, Inc. +/* Input parser for Bison -This file is part of Bison, the GNU Compiler Compiler. + Copyright (C) 1984, 1986, 1989, 1992, 1998, 2000, 2001, 2002, 2003, + 2005 Free Software Foundation, Inc. -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. + This file is part of Bison, the GNU Compiler Compiler. -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 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. -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. */ + 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., 51 Franklin Street, Fifth Floor, + Boston, MA 02110-1301, 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. +#include "system.h" -The entry point is reader(). */ +#include -#include -#include -#include "system.h" +#include "complain.h" +#include "conflicts.h" #include "files.h" -#include "new.h" -#include "symtab.h" -#include "lex.h" +#include "getargs.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 bucket *symval; -extern int numval; -extern int failure; -extern int expected_conflicts; -extern char *token_buffer; - -extern int atoi (); - -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 void fatal(); -extern void fatals(); -extern void unlex(); -extern void done(); - -extern int skip_white_space(); -extern int parse_percent_token(); -extern int lex(); - -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 copy_action(); -void readgram(); -void record_rule_line(); -void packsymbols(); -void output_token_defines(); -void packgram(); -int read_signed_integer(); -int get_type(); - -typedef - struct symbol_list - { - struct symbol_list *next; - bucket *sym; - bucket *ruleprec; - } - symbol_list; - - - -int lineno; -symbol_list *grammar; -int start_flag; -bucket *startval; -char **tags; - -/* 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 */ +#include "muscle_tab.h" +#include "output.h" +#include "reader.h" +#include "symlist.h" +#include "symtab.h" -static bucket *errtoken; +static symbol_list *grammar = NULL; +static bool start_flag = false; +merger_list *merge_functions; -/* Nonzero if any action or guard uses the @n construct. */ -static int yylsp_needed; +/* Has %union been seen? */ +bool typed = false; -extern char *version_string; +/* Should rules have a default precedence? */ +bool default_prec = true; + +/*-----------------------. +| Set the start symbol. | +`-----------------------*/ void -reader() +grammar_start_symbol_set (symbol *sym, location loc) { - 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("$illegal.")->class = STOKEN; - /* Read the declaration section. Copy %{ ... %} groups to ftable and fdefines file. - Also notice any %token, %left, etc. found there. */ - fprintf(ftable, "\n/* A Bison parser, made from %s", infile); - fprintf(ftable, " with Bison version %s */\n\n", version_string); - fprintf(ftable, "#define YYBISON 1 /* Identify Bison output. */\n\n"); - read_declarations(); - /* output the definition of YYLTYPE into the fattrs and fdefines files. */ - /* fattrs winds up in the .tab.c file, before bison.simple. */ - fprintf(fattrs, LTYPESTR); - /* 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 (yylsp_needed) + if (start_flag) + complain_at (loc, _("multiple %s declarations"), "%start"); + else { - if (fdefines) - fprintf(fdefines, LTYPESTR); + start_flag = true; + startsymbol = sym; + startsymbol_location = loc; } - /* 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(); } - -/* read from finput until %% is seen. Discard the %%. -Handle any % declarations, -and copy the contents of any %{ ... %} groups to fattrs. */ +/*----------------------------------------------------------------. +| There are two prologues: one before %union, one after. Augment | +| the current one. | +`----------------------------------------------------------------*/ void -read_declarations () +prologue_augment (const char *prologue, location loc) { - register int c; - register int tok; - - for (;;) - { - 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 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; - - default: - fatal("junk after `%%' in definition section"); - } - } - else if (c == EOF) - fatal("no input grammar"); - else if (c >= 040 && c <= 0177) - fatals ("unknown character `%c' in declaration section", c); - else - fatals ("unknown character with code 0x%x in declaration section", c); - } + struct obstack *oout = + !typed ? &pre_prologue_obstack : &post_prologue_obstack; + + obstack_fgrow1 (oout, "]b4_syncline(%d, [[", loc.start.line); + MUSCLE_OBSTACK_SGROW (oout, + quotearg_style (c_quoting_style, loc.start.file)); + obstack_sgrow (oout, "]])[\n"); + obstack_sgrow (oout, prologue); } + -/* copy the contents of a %{ ... %} into the definitions file. -The %{ has already been read. Return after reading the %}. */ +/*-------------------------------------------------------------------. +| Return the merger index for a merging function named NAME, whose | +| arguments have type TYPE. Records the function, if new, in | +| MERGER_LIST. | +`-------------------------------------------------------------------*/ -void -copy_definition () +static int +get_merge_function (uniqstr name, uniqstr type, location loc) { - 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); + merger_list *syms; + merger_list head; + int n; - after_percent = 0; + if (! glr_parser) + return 0; - c = getc(finput); + if (type == NULL) + type = uniqstr_new (""); - for (;;) + head.next = merge_functions; + for (syms = &head, n = 1; syms->next != NULL; syms = syms->next, n += 1) + if (UNIQSTR_EQ (name, syms->next->name)) + break; + if (syms->next == NULL) { - 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 || c == '\n') - fatal("unterminated string"); - - putc(c, fattrs); - - if (c == '\\') - { - c = getc(finput); - if (c == EOF) - fatal("unterminated string"); - 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) - { - if (c == '}') - return; - putc('%', fattrs); - } - after_percent = 0; - + syms->next = xmalloc (sizeof syms->next[0]); + syms->next->name = uniqstr_new (name); + syms->next->type = uniqstr_new (type); + syms->next->next = NULL; + merge_functions = head.next; } - + else if (!UNIQSTR_EQ (type, syms->next->type)) + warn_at (loc, _("result type clash on merge function %s: <%s> != <%s>"), + name, type, syms->next->type); + return n; } - - -/* 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. */ - -void -parse_token_decl (what_is, what_is_not) - int what_is, what_is_not; -{ -/* register int start_lineno; JF */ - register int token = 0; - register int prev; - register char *typename = 0; - int k; - -/* start_lineno = lineno; JF */ - - for (;;) - { - if(ungetc(skip_white_space(), finput) == '%') - return; - -/* if (lineno != start_lineno) - return; JF */ - - /* we have not passed a newline, so the token now starting is in this declaration */ - prev = token; - - token = lex(); - if (token == COMMA) - continue; - if (token == TYPENAME) - { - k = strlen(token_buffer); - typename = NEW2(k + 1, char); - strcpy(typename, token_buffer); - value_components_used = 1; - } - else if (token == IDENTIFIER) - { - int oldclass = symval->class; - - if (symval->class == what_is_not) - fatals("symbol %s redefined", symval->tag); - symval->class = what_is; - if (what_is == SNTERM && oldclass != SNTERM) - symval->value = nvars++; - - if (typename) - { - if (symval->type_name == NULL) - symval->type_name = typename; - else - fatals("type redeclaration for %s", symval->tag); - } - } - else if (prev == IDENTIFIER && token == NUMBER) - { - symval->user_token_number = numval; - translations = 1; - } - else - fatal("invalid text in %token or %nterm declaration"); - } - -} - - - -/* parse what comes after %start */ - -void -parse_start_decl () -{ - if (start_flag) - fatal("multiple %start declarations"); - start_flag = 1; - if (lex() != IDENTIFIER) - fatal("invalid %start declaration"); - startval = symval; -} - - - -/* read in a %type declaration and record its information for get_type_name to access */ +/*--------------------------------------. +| Free all merge-function definitions. | +`--------------------------------------*/ void -parse_type_decl () +free_merger_functions (void) { - register int k; - register char *name; -/* register int start_lineno; JF */ - - if (lex() != TYPENAME) - fatal("ill-formed %type declaration"); - - k = strlen(token_buffer); - name = NEW2(k + 1, char); - strcpy(name, token_buffer); - -/* start_lineno = lineno; */ - - for (;;) + merger_list *L0; + if (! glr_parser) + return; + L0 = merge_functions; + while (L0 != NULL) { - register int t; - - if(ungetc(skip_white_space(), finput) == '%') - return; - -/* if (lineno != start_lineno) - return; JF */ - - /* we have not passed a newline, so the token now starting is in this declaration */ - - t = lex(); - - switch (t) - { - - case COMMA: - case SEMICOLON: - break; - - case IDENTIFIER: - if (symval->type_name == NULL) - symval->type_name = name; - else - fatals("type redeclaration for %s", symval->tag); - - break; - - default: - fatal("invalid %type declaration"); - } + merger_list *L1 = L0->next; + free (L0); + L0 = L1; } } - - -/* read in a %left, %right or %nonassoc declaration and record its information. */ -/* assoc is either LEFT_ASSOC, RIGHT_ASSOC or NON_ASSOC. */ - + +/*-------------------------------------------------------------------. +| 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. */ +static symbol_list *grammar_end = NULL; + +/* Append SYM to the grammar. */ void -parse_assoc_decl (assoc) -int assoc; +grammar_symbol_append (symbol *sym, location loc) { - register int k; - register char *name = NULL; -/* register int start_lineno; JF */ - register int prev = 0; /* JF added = 0 to keep lint happy */ - - lastprec++; /* Assign a new precedence level, never 0. */ - -/* start_lineno = lineno; */ - - for (;;) - { - register int t; - - if(ungetc(skip_white_space(), finput) == '%') - return; + symbol_list *p = symbol_list_new (sym, loc); - /* if (lineno != start_lineno) - return; JF */ - - /* we have not passed a newline, so the token now starting is in this declaration */ - - 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) - fatals("redefining precedence of %s", symval->tag); - symval->prec = lastprec; - symval->assoc = assoc; - if (symval->class == SNTERM) - fatals("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 - fatals("type redeclaration for %s", symval->tag); - } - break; - - case NUMBER: - if (prev == IDENTIFIER) - { - symval->user_token_number = numval; - translations = 1; - } - else - fatal("invalid text in association declaration"); - break; - - case SEMICOLON: - return; - - default: - fatal("malformatted association declaration"); - } - - prev = t; + if (grammar_end) + grammar_end->next = p; + else + grammar = p; - } + grammar_end = p; } +/* The rule currently being defined, and the previous rule. + CURRENT_RULE points to the first LHS of the current rule, while + PREVIOUS_RULE_END points to the *end* of the previous rule (NULL). */ +symbol_list *current_rule = NULL; +static symbol_list *previous_rule_end = NULL; -/* 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. */ +/*----------------------------------------------. +| Create a new rule for LHS in to the GRAMMAR. | +`----------------------------------------------*/ void -parse_union_decl() +grammar_rule_begin (symbol *lhs, location loc) { - register int c; - register int count; - register int in_comment; - int cplus_comment; - - if (typed) - fatal("multiple %union declarations"); - - typed = 1; - - if (!nolinesflag) - fprintf(fattrs, "\n#line %d \"%s\"\n", lineno, infile); - else - fprintf(fattrs, "\n"); - - fprintf(fattrs, "typedef union"); - if (fdefines) - fprintf(fdefines, "typedef union"); - - count = 0; - in_comment = 0; - - c = getc(finput); - - while (c != EOF) + if (!start_flag) { - putc(c, fattrs); - if (fdefines) - putc(c, fdefines); - - 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"); - - 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) - fatal ("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; - } - } - - c = getc(finput); + startsymbol = lhs; + startsymbol_location = loc; + start_flag = true; } -} -/* parse the declaration %expect N which says to expect N - shift-reduce conflicts. */ + /* Start a new rule and record its lhs. */ + ++nrules; + ++nritems; -void -parse_expect_decl() -{ - register int c; - register int count; - char buffer[20]; + previous_rule_end = grammar_end; + grammar_symbol_append (lhs, loc); + current_rule = grammar_end; - c = getc(finput); - while (c == ' ' || c == '\t') - c = getc(finput); + /* Mark the rule's lhs as a nonterminal if not already so. */ - count = 0; - while (c >= '0' && c <= '9') + if (lhs->class == unknown_sym) { - if (count < 20) - buffer[count++] = c; - c = getc(finput); + lhs->class = nterm_sym; + lhs->number = nvars; + ++nvars; } - buffer[count] = 0; - - ungetc (c, finput); - - expected_conflicts = atoi (buffer); + else if (lhs->class == token_sym) + complain_at (loc, _("rule given for %s, which is a token"), lhs->tag); } -/* that's all of parsing the declaration section */ - -/* Get the data type (alternative in the union) of the value for symbol n in rule rule. */ +/* Check that the last rule (CURRENT_RULE) is properly defined. For + instance, there should be no type clash on the default action. */ -char * -get_type_name(n, rule) -int n; -symbol_list *rule; +static void +grammar_current_rule_check (void) { - static char *msg = "invalid $ value"; - - register int i; - register symbol_list *rp; - - if (n < 0) - fatal(msg); - - rp = rule; - i = 0; - - while (i < n) + symbol *lhs = current_rule->sym; + char const *lhs_type = lhs->type_name; + symbol *first_rhs = current_rule->next->sym; + + /* If there is an action, then there is nothing we can do: the user + is allowed to shoot herself in the foot. */ + if (current_rule->action) + return; + + /* Don't worry about the default action if $$ is untyped, since $$'s + value can't be used. */ + if (! lhs_type) + return; + + /* If $$ is being set in default way, report if any type mismatch. */ + if (first_rhs) { - rp = rp->next; - if (rp == NULL || rp->sym == NULL) - fatal(msg); - i++; + const char *rhs_type = first_rhs->type_name ? first_rhs->type_name : ""; + if (!UNIQSTR_EQ (lhs_type, rhs_type)) + warn_at (current_rule->location, + _("type clash on default action: <%s> != <%s>"), + lhs_type, rhs_type); } - - return (rp->sym->type_name); + /* Warn if there is no default for $$ but we need one. */ + else + warn_at (current_rule->location, + _("empty rule for typed nonterminal, and no 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. */ +/*-------------------------------------. +| End the currently being grown rule. | +`-------------------------------------*/ void -copy_guard(rule, stack_offset) -symbol_list *rule; -int stack_offset; +grammar_rule_end (location loc) { - 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 - fatal("unmatched right brace ('}')"); - break; - - case '\'': - case '"': - match = c; - putc(c, fguard); - c = getc(finput); - - while (c != match) - { - if (c == EOF || c == '\n') - fatal("unterminated string"); - - 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) /* JF */ - fprintf(stderr,"%s:%d: warning: $$ of '%s' has no declared type.\n",infile,lineno,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) /* JF */ - fprintf(stderr,"%s:%d: warning: $%d of '%s' has no declared type.\n",infile,lineno,n,rule->sym->tag); - continue; - } - else - fatals("$%c is invalid",c); /* JF changed style */ - - break; - - case '@': - c = getc(finput); - if (isdigit(c) || c == '-') - { - ungetc (c, finput); - n = read_signed_integer(finput); - c = getc(finput); - } - else - fatals("@%c is invalid",c); /* JF changed style */ - - fprintf(fguard, "yylsp[%d]", n - stack_offset); - yylsp_needed = 1; - - continue; - - case EOF: - fatal("unterminated %guard clause"); - - default: - putc(c, fguard); - } - - if (c != '}' || count != 0) - c = getc(finput); - } - - c = skip_white_space(); - - fprintf(fguard, ";\n break;}"); - if (c == '{') - copy_action(rule, stack_offset); - else if (c == '=') - { - c = getc(finput); - if (c == '{') - copy_action(rule, stack_offset); - } - else - ungetc(c, finput); + /* Put an empty link in the list to mark the end of this rule */ + grammar_symbol_append (NULL, grammar_end->location); + current_rule->location = loc; + grammar_current_rule_check (); } - -/* 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. */ +/*-------------------------------------------------------------------. +| 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 -copy_action(rule, stack_offset) -symbol_list *rule; -int stack_offset; +grammar_midrule_action (void) { - 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 == EOF || c == '\n') - fatal("unterminated string"); - - 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) /* JF */ - fprintf(stderr,"%s:%d: warning: $$ of '%s' has no declared type.\n",infile,lineno,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) /* JF */ - fprintf(stderr,"%s:%d: warning: $%d of '%s' has no declared type.\n",infile,lineno,n,rule->sym->tag); - continue; - } - else - fatals("$%c is invalid",c); /* JF changed format */ - - break; - - case '@': - c = getc(finput); - if (isdigit(c) || c == '-') - { - ungetc (c, finput); - n = read_signed_integer(finput); - c = getc(finput); - } - else - fatal("invalid @-construct"); - - 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); - } - } - - fprintf(faction, ";\n break;}"); -} - - + /* 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, whose location is that of the midrule + action. Create the MIDRULE. */ + location dummy_location = current_rule->action_location; + symbol *dummy = dummy_symbol_get (dummy_location); + symbol_list *midrule = symbol_list_new (dummy, dummy_location); + + /* 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 location and actions to that of the DUMMY. */ + midrule->location = dummy_location; + midrule->action = current_rule->action; + midrule->action_location = dummy_location; + current_rule->action = NULL; + + if (previous_rule_end) + previous_rule_end->next = midrule; + else + grammar = midrule; -/* generate a dummy symbol, a nonterminal, -whose name cannot conflict with the user's names. */ + /* End the dummy's rule. */ + previous_rule_end = symbol_list_new (NULL, dummy_location); + previous_rule_end->next = current_rule; -bucket * -gensym() -{ - register bucket *sym; + midrule->next = previous_rule_end; - sprintf (token_buffer, "@%d", ++gensym_count); - sym = getsym(token_buffer); - sym->class = SNTERM; - sym->value = nvars++; - return (sym); + /* Insert the dummy nonterminal replacing the midrule action into + the current rule. */ + grammar_current_rule_symbol_append (dummy, dummy_location); } -/* 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. */ +/* Set the precedence symbol of the current rule to PRECSYM. */ void -readgram() +grammar_current_rule_prec_set (symbol *precsym, location loc) { - 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; - - t = lex(); - if (t != COLON) - fatal("ill-formed rule"); - } - - if (nrules == 0) - { - if (t == BAR) - fatal("grammar starts with vertical bar"); - - if (!start_flag) - startval = lhs; - } - - /* 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) - fatals("rule given for %s, which is a token", lhs->tag); - - /* read the rhs of the rule. */ - - for (;;) - { - 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 write 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++; - } - - /* 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) - { - t = lex(); - crule->ruleprec = symval; - t = lex(); - } - if (t == GUARD) - { - if (! semantic_parser) - fatal("%guard present but %semantic_parser not specified"); - - copy_guard(crule, rulelength); - t = lex(); - } - else if (t == LEFT_CURLY) - { - if (actionflag) fatal("two actions at end of one rule"); - copy_action(crule, rulelength); - t = lex(); - } - /* If $$ is being set in default way, - warn if any type mismatch. */ - else if (!xactions && first_rhs && lhs->type_name != first_rhs->type_name) - { - if (lhs->type_name == 0 || first_rhs->type_name == 0 - || strcmp(lhs->type_name,first_rhs->type_name)) - fprintf(stderr, "%s:%d: warning: type clash ('%s' '%s') on default action\n", - infile, - lineno, - lhs->type_name ? lhs->type_name : "", - first_rhs->type_name ? first_rhs->type_name : ""); - } - /* Warn if there is no default for $$ but we need one. */ - else if (!xactions && !first_rhs && lhs->type_name != 0) - fprintf(stderr, - "%s:%d: warning: empty rule for typed nonterminal, and no action\n", - infile, - lineno); - if (t == SEMICOLON) - t = lex(); - } - /* these things can appear as alternatives to 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(); - } - else - fatal("invalid input"); - } - - if (nsyms > MAXSHORT) - fatals("too many symbols (tokens plus nonterminals); maximum %d", - MAXSHORT); - if (nrules == 0) - fatal("no 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"); - } - - /* Report any undefined symbols and consider them nonterminals. */ - - for (bp = firstsymbol; bp; bp = bp->next) - if (bp->class == SUNKNOWN) - { - fprintf(stderr, "symbol %s used, not defined as token, and no rules for it\n", - bp->tag); - failure = 1; - bp->class = SNTERM; - bp->value = nvars++; - } - - ntokens = nsyms - nvars; + if (current_rule->ruleprec) + complain_at (loc, _("only one %s allowed per rule"), "%prec"); + current_rule->ruleprec = precsym; } +/* Attach dynamic precedence DPREC to the current rule. */ void -record_rule_line () +grammar_current_rule_dprec_set (int dprec, location loc) { - /* 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 (! glr_parser) + warn_at (loc, _("%s affects only GLR parsers"), "%dprec"); + if (dprec <= 0) + complain_at (loc, _("%s must be followed by positive number"), "%dprec"); + else if (current_rule->dprec != 0) + complain_at (loc, _("only one %s allowed per rule"), "%dprec"); + current_rule->dprec = dprec; } +/* Attach a merge function NAME with argument type TYPE to current + rule. */ -/* read in a %type declaration and record its information for get_type_name to access */ - -int -get_type() +void +grammar_current_rule_merge_set (uniqstr name, location loc) { - register int k; - register int t; - register char *name; - - t = lex(); - - if (t != TYPENAME) - fatal("ill-formed %type declaration"); - - 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 - fatals("type redeclaration for %s", symval->tag); - - break; - - default: - return (t); - } - } + if (! glr_parser) + warn_at (loc, _("%s affects only GLR parsers"), "%merge"); + if (current_rule->merger != 0) + complain_at (loc, _("only one %s allowed per rule"), "%merge"); + current_rule->merger = + get_merge_function (name, current_rule->sym->type_name, loc); } - - -/* assign symbol numbers, and write definition of token names into fdefines. -Set up vectors tags and sprec of names and precedences of symbols. */ +/* Attach SYM to the current rule. If needed, move the previous + action as a mid-rule action. */ void -packsymbols() +grammar_current_rule_symbol_append (symbol *sym, location loc) { - register bucket *bp; - register int tokno = 1; - register int i; - register int last_user_token_number; - - /* int lossage = 0; JF set but not used */ - - tags = NEW2(nsyms + 1, char *); - tags[0] = "$"; - - sprec = NEW2(nsyms, short); - sassoc = NEW2(nsyms, short); - - max_user_token_number = 256; - last_user_token_number = 256; - - for (bp = firstsymbol; bp; bp = bp->next) - { - if (bp->class == SNTERM) - { - bp->value += ntokens; - } - else - { - 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; - bp->value = tokno++; - } - - tags[bp->value] = bp->tag; - sprec[bp->value] = bp->prec; - sassoc[bp->value] = bp->assoc; - - } - - 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 $illegal., 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; - if (translations) - { - if (token_translations[bp->user_token_number] != 2) - { - /* JF made this a call to fatals() */ - fatals( "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; - } - } - - error_token_number = errtoken->value; - - output_token_defines(ftable); - - 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 (current_rule->action) + grammar_midrule_action (); + ++nritems; + grammar_symbol_append (sym, loc); } - + +/* Attach an ACTION to the current rule. If needed, move the previous + action as a mid-rule action. */ void -output_token_defines(file) -FILE *file; +grammar_current_rule_action_append (const char *action, location loc) { - bucket *bp; - - for (bp = firstsymbol; bp; bp = bp->next) - { - if (bp->value >= ntokens) continue; - - /* For named tokens, but not literal ones, define the name. */ - /* The value is the user token number. */ - - if ('\'' != *tags[bp->value] && bp != errtoken) - { - register char *cp = tags[bp->value]; - register char c; - - /* Don't #define nonliteral tokens whose names contain periods. */ - - while ((c = *cp++) && c != '.'); - if (!c) - { - fprintf(file, "#define\t%s\t%d\n", tags[bp->value], - (translations ? bp->user_token_number : bp->value)); - if (semantic_parser) - fprintf(file, "#define\tT%s\t%d\n", tags[bp->value], - bp->value); - } - } - } - - putc('\n', file); + if (current_rule->action) + grammar_midrule_action (); + current_rule->action = action; + current_rule->action_location = loc; } + +/*---------------------------------------------------------------. +| Convert the rules into the representation using RRHS, RLHS and | +| RITEM. | +`---------------------------------------------------------------*/ - -/* convert the rules into the representation using rrhs, rlhs and ritems. */ - -void -packgram() +static void +packgram (void) { - register int itemno; - register int ruleno; - register symbol_list *p; -/* register bucket *bp; JF unused */ + unsigned int itemno = 0; + rule_number ruleno = 0; + symbol_list *p = grammar; - bucket *ruleprec; + ritem = xnmalloc (nritems, sizeof *ritem); + rules = xnmalloc (nrules, sizeof *rules); - 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; - - itemno = 0; - ruleno = 1; - - p = grammar; while (p) { - rlhs[ruleno] = p->sym->value; - rrhs[ruleno] = itemno; - ruleprec = p->ruleprec; + symbol *ruleprec = p->ruleprec; + rules[ruleno].user_number = ruleno; + rules[ruleno].number = ruleno; + rules[ruleno].lhs = p->sym; + rules[ruleno].rhs = ritem + itemno; + rules[ruleno].prec = NULL; + rules[ruleno].dprec = p->dprec; + rules[ruleno].merger = p->merger; + rules[ruleno].precsym = NULL; + rules[ruleno].location = p->location; + rules[ruleno].useful = true; + rules[ruleno].action = p->action; + rules[ruleno].action_location = p->action_location; p = p->next; while (p && p->sym) { - ritem[itemno++] = p->sym->value; + /* item_number = symbol_number. + 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 == STOKEN) - { - rprec[ruleno] = p->sym->prec; - rassoc[ruleno] = p->sym->assoc; - } - if (p) p = p->next; + if (p->sym->class == token_sym && default_prec) + rules[ruleno].prec = p->sym; + if (p) + p = p->next; } /* If this rule has a %prec, - the specified symbol's precedence replaces the default. */ + the specified symbol's precedence replaces the default. */ if (ruleprec) { - rprec[ruleno] = ruleprec->prec; - rassoc[ruleno] = ruleprec->assoc; - rprecsym[ruleno] = ruleprec->value; + rules[ruleno].precsym = ruleprec; + rules[ruleno].prec = ruleprec; } + ritem[itemno++] = rule_number_as_item_number (ruleno); + ++ruleno; - ritem[itemno++] = -ruleno; - ruleno++; - - if (p) p = p->next; + if (p) + p = p->next; } - ritem[itemno] = 0; + if (itemno != nritems) + abort (); + + if (trace_flag & trace_sets) + ritem_print (stderr); } -/* Read a signed integer from STREAM and return its value. */ +/*------------------------------------------------------------------. +| 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. | +`------------------------------------------------------------------*/ -int -read_signed_integer (stream) - FILE *stream; +void +reader (void) { - register int c = getc(stream); - register int sign = 1; - register int n; + /* Initialize the symbol table. */ + symbols_new (); + + /* Construct the accept symbol. */ + accept = symbol_get ("$accept", empty_location); + accept->class = nterm_sym; + accept->number = nvars++; + + /* Construct the error token */ + errtoken = symbol_get ("error", empty_location); + errtoken->class = token_sym; + errtoken->number = ntokens++; + + /* Construct a token that represents all undefined literal tokens. + It is always token number 2. */ + undeftoken = symbol_get ("$undefined", empty_location); + undeftoken->class = token_sym; + undeftoken->number = ntokens++; + + /* Initialize the obstacks. */ + obstack_init (&pre_prologue_obstack); + obstack_init (&post_prologue_obstack); + + finput = xfopen (grammar_file, "r"); + gram_in = finput; + + gram__flex_debug = trace_flag & trace_scan; + gram_debug = trace_flag & trace_parse; + scanner_initialize (); + gram_parse (); + + /* If something went wrong during the parsing, don't try to + continue. */ + if (complaint_issued) + return; + + /* Grammar has been read. Do some checking */ + if (nrules == 0) + fatal (_("no rules in the input grammar")); - if (c == '-') - { - c = getc(stream); - sign = -1; - } - n = 0; - while (isdigit(c)) + /* Report any undefined symbols and consider them nonterminals. */ + symbols_check_defined (); + + /* If the user did not define her ENDTOKEN, do it now. */ + if (!endtoken) { - n = 10*n + (c - '0'); - c = getc(stream); + endtoken = symbol_get ("$end", empty_location); + endtoken->class = token_sym; + endtoken->number = 0; + /* Value specified by POSIX. */ + endtoken->user_token_number = 0; } - ungetc(c, stream); + /* Insert the initial rule, which line is that of the first rule + (not that of the start symbol): + + accept: %start EOF. */ + { + symbol_list *p = symbol_list_new (accept, empty_location); + p->location = grammar->location; + p->next = symbol_list_new (startsymbol, empty_location); + p->next->next = symbol_list_new (endtoken, empty_location); + p->next->next->next = symbol_list_new (NULL, empty_location); + p->next->next->next->next = grammar; + nrules += 1; + nritems += 3; + grammar = p; + } + + if (! (nsyms <= SYMBOL_NUMBER_MAXIMUM && nsyms == ntokens + nvars)) + abort (); + + xfclose (finput); + + /* Assign the symbols their symbol numbers. Write #defines for the + token symbols into FDEFINES if requested. */ + symbols_pack (); + + /* 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); }