X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/943819bf464c934abcaf219bf0578b393685c620..4b7a4c1b1c8c18e9ad2517c117442b9b7d7e671a:/src/reader.c diff --git a/src/reader.c b/src/reader.c index 662353b3..043fea8b 100644 --- a/src/reader.c +++ b/src/reader.c @@ -1,2073 +1,719 @@ -/* Input parser for bison - Copyright (C) 1984, 1986, 1989, 1992 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, 2006, 2007, 2009 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. + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, 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. */ + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + You should have received a copy of the GNU General Public License + along with this program. If not, see . */ -/* 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 +#include "system.h" -The entry point is reader(). */ +#include +#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 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; - - - -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 bucket *errtoken; - -/* Nonzero if any action or guard uses the @n construct. */ -static int yylsp_needed; +#include "muscle_tab.h" +#include "reader.h" +#include "symlist.h" +#include "symtab.h" +#include "scan-gram.h" +#include "scan-code.h" -extern char *version_string; +static void prepare_percent_define_front_end_variables (void); +static void check_and_convert_grammar (void); +static symbol_list *grammar = NULL; +static bool start_flag = false; +merger_list *merge_functions; -static void -skip_to_char(target) - int target; -{ - int c; - if (target == '\n') - warn(" Skipping to next \\n"); - else - warni(" Skipping to next %c", target); +/* Was %union seen? */ +bool union_seen = false; - do - c = skip_white_space(); - while (c != target && c != EOF); - if (c != EOF) - ungetc(c, finput); -} +/* Was a tag seen? */ +bool tag_seen = false; +/* 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("$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); + if (start_flag) + complain_at (loc, _("multiple %s declarations"), "%start"); 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 () -{ - 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 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('%'); - } + start_flag = true; + startsymbol = sym; + startsymbol_location = loc; } } + -/* 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); - - for (;;) - { - 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) - { - if (c == '}') - return; - putc('%', fattrs); - } - after_percent = 0; - - } - -} - - - -/* 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. */ +/*------------------------------------------------------------------------. +| Return the merger index for a merging function named NAME. Records the | +| function, if new, in MERGER_LIST. | +`------------------------------------------------------------------------*/ -void -parse_token_decl (what_is, what_is_not) - int what_is, what_is_not; +static int +get_merge_function (uniqstr name) { - register int token = 0; - register char *typename = 0; - register struct bucket *symbol = NULL; /* pts to symbol being defined */ - int k; - - for (;;) + merger_list *syms; + merger_list head; + int n; + + if (! glr_parser) + return 0; + + head.next = merge_functions; + for (syms = &head, n = 1; syms->next; syms = syms->next, n += 1) + if (UNIQSTR_EQ (name, syms->next->name)) + break; + if (syms->next == NULL) { - 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('%'); - } + syms->next = xmalloc (sizeof syms->next[0]); + syms->next->name = uniqstr_new (name); + /* After all symbol type declarations have been parsed, packgram invokes + record_merge_function_type to set the type. */ + syms->next->type = NULL; + syms->next->next = NULL; + merge_functions = head.next; } - + return n; } -/* parse what comes after %thong - the full syntax is - %thong token number literal - the 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 , 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 -*/ +/*-------------------------------------------------------------------------. +| For the existing merging function with index MERGER, record the result | +| type as TYPE as required by the lhs of the rule whose %merge declaration | +| is at DECLARATION_LOC. | +`-------------------------------------------------------------------------*/ -void -parse_thong_decl () +static void +record_merge_function_type (int merger, uniqstr type, location declaration_loc) { - 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; - - 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 != '\"') + int merger_find; + merger_list *merge_function; + + if (merger <= 0) + return; + + if (type == NULL) + type = uniqstr_new (""); + + merger_find = 1; + for (merge_function = merge_functions; + merge_function != NULL && merger_find != merger; + merge_function = merge_function->next) + merger_find += 1; + aver (merge_function != NULL && merger_find == merger); + if (merge_function->type != NULL && !UNIQSTR_EQ (merge_function->type, type)) { - warns("expected string constant instead of %s", - token_buffer); - skip_to_char('%'); - return; + complain_at (declaration_loc, + _("result type clash on merge function `%s': <%s> != <%s>"), + merge_function->name, type, merge_function->type); + complain_at (merge_function->type_declaration_location, + _("previous declaration")); } - 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 */ + merge_function->type = uniqstr_new (type); + merge_function->type_declaration_location = declaration_loc; } - -/* parse what comes after %start */ +/*--------------------------------------. +| Free all merge-function definitions. | +`--------------------------------------*/ void -parse_start_decl () +free_merger_functions (void) { - if (start_flag) - warn("multiple %start declarations"); - if (lex() != IDENTIFIER) - warn("invalid %start declaration"); - else + merger_list *L0 = merge_functions; + while (L0) { - start_flag = 1; - startval = symval; + merger_list *L1 = L0->next; + free (L0); + L0 = L1; } } - - -/* read in a %type declaration and record its information for get_type_name to access */ - -void -parse_type_decl () + +/*-------------------------------------------------------------------. +| 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. | +`-------------------------------------------------------------------*/ + +/* The (currently) last symbol of GRAMMAR. */ +static symbol_list *grammar_end = NULL; + +/* Append SYM to the grammar. */ +static symbol_list * +grammar_symbol_append (symbol *sym, location loc) { - register int k; - register char *name; + symbol_list *p = symbol_list_sym_new (sym, loc); - if (lex() != TYPENAME) - { - warn("%type declaration has no "); - skip_to_char('%'); - return; - } - - k = strlen(token_buffer); - name = NEW2(k + 1, char); - strcpy(name, token_buffer); - - for (;;) - { - register int t; - - if(ungetc(skip_white_space(), finput) == '%') - return; - - t = lex(); - - switch (t) - { - - case COMMA: - case SEMICOLON: - break; + if (grammar_end) + grammar_end->next = p; + else + grammar = p; - 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); + grammar_end = p; - break; + /* A null SYM stands for an end of rule; it is not an actual + part of it. */ + if (sym) + ++nritems; - default: - warns("invalid %%type declaration due to item: `%s'", token_buffer); - skip_to_char('%'); - } - } + return p; } - - -/* read in a %left, %right or %nonassoc declaration and record its information. */ -/* assoc is either LEFT_ASSOC, RIGHT_ASSOC or NON_ASSOC. */ - -void -parse_assoc_decl (assoc) -int assoc; +static void +assign_named_ref (symbol_list *p, named_ref *name) { - register int k; - register char *name = NULL; - register int prev = 0; + symbol *sym = p->content.sym; - lastprec++; /* Assign a new precedence level, never 0. */ - - for (;;) + if (name->id == sym->tag) { - 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('%'); - } - - prev = t; - + warn_at (name->loc, + _("duplicated symbol name for %s ignored"), + quote (sym->tag)); + named_ref_free (name); } + else + p->named_ref = name; } +/* 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). */ +static 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_current_rule_begin (symbol *lhs, location loc, + named_ref *lhs_name) { - register int c; - register int count; - register int in_comment; - int cplus_comment; - - if (typed) - warn("multiple %union declarations"); + symbol_list* p; - typed = 1; + /* Start a new rule and record its lhs. */ + ++nrules; + previous_rule_end = grammar_end; - 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; + p = grammar_symbol_append (lhs, loc); + if (lhs_name) + assign_named_ref(p, lhs_name); - c = getc(finput); + current_rule = grammar_end; - while (c != EOF) + /* Mark the rule's lhs as a nonterminal if not already so. */ + if (lhs->class == unknown_sym) { - 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 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; - } - } - - c = getc(finput); + lhs->class = nterm_sym; + lhs->number = nvars; + ++nvars; } + else if (lhs->class == token_sym) + complain_at (loc, _("rule given for %s, which is a token"), lhs->tag); } -/* parse the declaration %expect N which says to expect N - shift-reduce conflicts. */ -void -parse_expect_decl() -{ - register int c; - register int count; - char buffer[20]; +/*----------------------------------------------------------------------. +| A symbol should be used if either: | +| 1. It has a destructor. | +| 2. --warnings=midrule-values and the symbol is a mid-rule symbol | +| (i.e., the generated LHS replacing a mid-rule action) that was | +| assigned to or used, as in "exp: { $$ = 1; } { $$ = $1; }". | +`----------------------------------------------------------------------*/ - c = getc(finput); - while (c == ' ' || c == '\t') - c = getc(finput); - - count = 0; - while (c >= '0' && c <= '9') - { - if (count < 20) - buffer[count++] = c; - c = getc(finput); - } - buffer[count] = 0; - - ungetc (c, finput); - - if (count <= 0 || count > 10) - warn("argument of %expect is not an integer"); - expected_conflicts = atoi (buffer); +static bool +symbol_should_be_used (symbol_list const *s) +{ + if (symbol_destructor_get (s->content.sym)->code) + return true; + if (warnings_flag & warnings_midrule_values) + return ((s->midrule && s->midrule->action_props.is_value_used) + || (s->midrule_parent_rule + && symbol_list_n_get (s->midrule_parent_rule, + s->midrule_parent_rhs_index) + ->action_props.is_value_used)); + return false; } -/* 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 rule R 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_rule_check (const symbol_list *r) { - static char *msg = "invalid $ value"; + /* Type check. - register int i; - register symbol_list *rp; + If there is an action, then there is nothing we can do: the user + is allowed to shoot herself in the foot. - if (n < 0) + Don't worry about the default action if $$ is untyped, since $$'s + value can't be used. */ + if (!r->action_props.code && r->content.sym->type_name) { - warn(msg); - return NULL; - } - - rp = rule; - i = 0; - - while (i < n) - { - rp = rp->next; - if (rp == NULL || rp->sym == NULL) + symbol *first_rhs = r->next->content.sym; + /* If $$ is being set in default way, report if any type mismatch. */ + if (first_rhs) { - warn(msg); - return NULL; + char const *lhs_type = r->content.sym->type_name; + const char *rhs_type = + first_rhs->type_name ? first_rhs->type_name : ""; + if (!UNIQSTR_EQ (lhs_type, rhs_type)) + warn_at (r->location, + _("type clash on default action: <%s> != <%s>"), + lhs_type, rhs_type); } - i++; + /* Warn if there is no default for $$ but we need one. */ + else + warn_at (r->location, + _("empty rule for typed nonterminal, and no action")); } - return (rp->sym->type_name); -} - - -/* 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; -{ - 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) + /* Check that symbol values that should be used are in fact used. */ + { + symbol_list const *l = r; + int n = 0; + for (; l && l->content.sym; l = l->next, ++n) + if (! (l->action_props.is_value_used + || !symbol_should_be_used (l) + /* The default action, $$ = $1, `uses' both. */ + || (!r->action_props.code && (n == 0 || n == 1)))) { - case '\n': - putc(c, fguard); - lineno++; - break; - - case '{': - putc(c, fguard); - brace_flag = 1; - count++; - break; - - case '}': - putc(c, fguard); - if (count > 0) - count--; - else - { - warn("unmatched right brace (`}')"); - c = getc(finput); /* skip it */ - } - break; - - case '\'': - case '"': - match = c; - putc(c, fguard); - c = getc(finput); - - while (c != match) - { - if (c == EOF) - fatal("unterminated string at end of file"); - if (c == '\n') - { - warn("unterminated string"); - ungetc(c, finput); - c = match; /* invent terminator */ - continue; - } - - putc(c, fguard); - - if (c == '\\') - { - c = getc(finput); - if (c == EOF) - fatal("unterminated string"); - putc(c, fguard); - if (c == '\n') - lineno++; - } - - c = getc(finput); - } - - putc(c, fguard); - break; - - case '/': - putc(c, fguard); - c = getc(finput); - if (c != '*' && c != '/') - continue; - - cplus_comment = (c == '/'); - putc(c, fguard); - c = getc(finput); - - ended = 0; - while (!ended) - { - if (!cplus_comment && c == '*') - { - while (c == '*') - { - putc(c, fguard); - c = getc(finput); - } - - if (c == '/') - { - putc(c, fguard); - ended = 1; - } - } - else if (c == '\n') - { - lineno++; - putc(c, fguard); - if (cplus_comment) - ended = 1; - else - c = getc(finput); - } - else if (c == EOF) - fatal("unterminated comment"); - else - { - putc(c, fguard); - c = getc(finput); - } - } - - break; - - case '$': - c = getc(finput); - type_name = NULL; - - if (c == '<') - { - register char *cp = token_buffer; - - while ((c = getc(finput)) != '>' && c > 0) - *cp++ = c; - *cp = 0; - type_name = token_buffer; - - c = getc(finput); - } - - if (c == '$') - { - fprintf(fguard, "yyval"); - if (!type_name) type_name = rule->sym->type_name; - if (type_name) - fprintf(fguard, ".%s", type_name); - if(!type_name && typed) - warns("$$ 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); - } + if (n) + warn_at (r->location, _("unused value: $%d"), n); 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); + warn_at (r->location, _("unset value: $$")); } + } +} - if (c != '}' || count != 0) - c = getc(finput); - } - c = skip_white_space(); +/*-------------------------------------. +| End the currently being grown rule. | +`-------------------------------------*/ - fprintf(fguard, ";\n break;}"); - if (c == '{') - copy_action(rule, stack_offset); - else if (c == '=') - { - c = getc(finput); /* why not skip_white_space -wjh */ - if (c == '{') - copy_action(rule, stack_offset); - } - else - ungetc(c, finput); +void +grammar_current_rule_end (location loc) +{ + /* 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; } - -/* 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 == '\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); - } + /* 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_props.location; + symbol *dummy = dummy_symbol_get (dummy_location); + symbol_list *midrule = symbol_list_sym_new (dummy, dummy_location); + + /* Remember named_ref of previous action. */ + named_ref *action_name = current_rule->action_props.named_ref; + + /* 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; + code_props_rule_action_init (&midrule->action_props, + current_rule->action_props.code, + current_rule->action_props.location, + midrule, 0); + code_props_none_init (¤t_rule->action_props); + + if (previous_rule_end) + previous_rule_end->next = midrule; + else + grammar = midrule; - /* above loop exits when c is '}' */ + /* End the dummy's rule. */ + midrule->next = symbol_list_sym_new (NULL, dummy_location); + midrule->next->next = current_rule; - if (--count) - { - putc(c, faction); - c = getc(finput); - } - } + previous_rule_end = midrule->next; - fprintf(faction, ";\n break;}"); + /* Insert the dummy nonterminal replacing the midrule action into + the current rule. Bind it to its dedicated rule. */ + grammar_current_rule_symbol_append (dummy, dummy_location, + action_name); + grammar_end->midrule = midrule; + midrule->midrule_parent_rule = current_rule; + midrule->midrule_parent_rhs_index = symbol_list_length (current_rule->next); } +/* Set the precedence symbol of the current rule to PRECSYM. */ - -/* generate a dummy symbol, a nonterminal, -whose name cannot conflict with the user's names. */ - -bucket * -gensym() +void +grammar_current_rule_prec_set (symbol *precsym, location loc) { - register bucket *sym; - - sprintf (token_buffer, "@%d", ++gensym_count); - sym = getsym(token_buffer); - sym->class = SNTERM; - sym->value = nvars++; - return (sym); + symbol_class_set (precsym, token_sym, loc, false); + if (current_rule->ruleprec) + complain_at (loc, _("only one %s allowed per rule"), "%prec"); + current_rule->ruleprec = precsym; } -/* 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. */ +/* Attach dynamic precedence DPREC to the current rule. */ void -readgram() +grammar_current_rule_dprec_set (int dprec, 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; - - 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"); - } - - /* Report any undefined symbols and consider them nonterminals. */ - - 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++; - } - - ntokens = nsyms - nvars; + 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. */ void -record_rule_line () +grammar_current_rule_merge_set (uniqstr name, 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"), "%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->merger_declaration_location = loc; } +/* Attach SYM 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 *sym, location loc, + named_ref *name) { - 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); - } - } + symbol_list *p; + if (current_rule->action_props.code) + grammar_midrule_action (); + p = grammar_symbol_append (sym, loc); + if (name) + assign_named_ref(p, name); } - - -/* 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. */ void -packsymbols() +grammar_current_rule_action_append (const char *action, location loc, + named_ref *name) { - register bucket *bp; - register int tokno = 1; - register int i; - register int last_user_token_number; + if (current_rule->action_props.code) + grammar_midrule_action (); + /* After all symbol declarations have been parsed, packgram invokes + code_props_translate_code. */ + code_props_rule_action_init (¤t_rule->action_props, action, loc, + current_rule, name); +} - /* int lossage = 0; JF set but not used */ + +/*---------------------------------------------------------------. +| 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 = 0; + rule_number ruleno = 0; + symbol_list *p = grammar; - sprec = NEW2(nsyms, short); - sassoc = NEW2(nsyms, short); + ritem = xnmalloc (nritems + 1, sizeof *ritem); - max_user_token_number = 256; - last_user_token_number = 256; + /* This sentinel is used by build_relations in gram.c. */ + *ritem++ = 0; - for (bp = firstsymbol; bp; bp = bp->next) + rules = xnmalloc (nrules, sizeof *rules); + + while (p) { - if (bp->class == SNTERM) + int rule_length = 0; + symbol *ruleprec = p->ruleprec; + record_merge_function_type (p->merger, p->content.sym->type_name, + p->merger_declaration_location); + rules[ruleno].user_number = ruleno; + rules[ruleno].number = ruleno; + rules[ruleno].lhs = p->content.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_props.code; + rules[ruleno].action_location = p->action_props.location; + + /* If the midrule's $$ is set or its $n is used, remove the `$' from the + symbol name so that it's a user-defined symbol so that the default + %destructor and %printer apply. */ + if (p->midrule_parent_rule + && (p->action_props.is_value_used + || symbol_list_n_get (p->midrule_parent_rule, + p->midrule_parent_rhs_index) + ->action_props.is_value_used)) + p->content.sym->tag += 1; + + /* Don't check the generated rule 0. It has no action, so some rhs + symbols may appear unused, but the parsing algorithm ensures that + %destructor's are invoked appropriately. */ + if (p != grammar) + grammar_rule_check (p); + + for (p = p->next; p && p->content.sym; p = p->next) { - 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 */ - { - bp->value = tokno++; + ++rule_length; + + /* Don't allow rule_length == INT_MAX, since that might + cause confusion with strtol if INT_MAX == LONG_MAX. */ + if (rule_length == INT_MAX) + fatal_at (rules[ruleno].location, _("rule is too long")); + + /* item_number = symbol_number. + But the former needs to contain more: negative rule numbers. */ + ritem[itemno++] = + symbol_number_as_item_number (p->content.sym->number); + /* A rule gets by default the precedence and associativity + of its last token. */ + if (p->content.sym->class == token_sym && default_prec) + rules[ruleno].prec = p->content.sym; } - 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; } - - tags[bp->value] = bp->tag; - user_toknums[bp->value] = bp->user_token_number; - sprec[bp->value] = bp->prec; - sassoc[bp->value] = bp->assoc; - + /* An item ends by the rule number (negated). */ + ritem[itemno++] = rule_number_as_item_number (ruleno); + aver (itemno < ITEM_NUMBER_MAX); + ++ruleno; + aver (ruleno < RULE_NUMBER_MAX); + + if (p) + p = p->next; } - if (translations) - { - register int i; + aver (itemno == nritems); - token_translations = NEW2(max_user_token_number+1, short); + if (trace_flag & trace_sets) + ritem_print (stderr); +} + +/*------------------------------------------------------------------. +| 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. | +`------------------------------------------------------------------*/ - /* 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; +void +reader (void) +{ + /* Initialize the symbol table. */ + symbols_new (); - 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; - } - } + /* Construct the accept symbol. */ + accept = symbol_get ("$accept", empty_location); + accept->class = nterm_sym; + accept->number = nvars++; - error_token_number = errtoken->value; + /* Construct the error token */ + errtoken = symbol_get ("error", empty_location); + errtoken->class = token_sym; + errtoken->number = ntokens++; - if (! noparserflag) - output_token_defines(ftable); + /* 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++; - 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); + gram_in = xfopen (grammar_file, "r"); - start_symbol = startval->value; + gram__flex_debug = trace_flag & trace_scan; + gram_debug = trace_flag & trace_parse; + gram_scanner_initialize (); + gram_parse (); + prepare_percent_define_front_end_variables (); - if (definesflag) - { - output_token_defines(fdefines); + if (! complaint_issued) + check_and_convert_grammar (); - 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 - } + xfclose (gram_in); } - -/* For named tokens, but not literal ones, define the name. - The value is the user token number. -*/ -void -output_token_defines(file) -FILE *file; -{ - bucket *bp; - register char *cp, *symbol; - register char c; - - for (bp = firstsymbol; bp; bp = bp->next) - { - symbol = bp->tag; /* get symbol */ - - if (bp->value >= ntokens) continue; - if (bp->user_token_number == SALIAS) continue; - if ('\'' == *symbol) continue; /* skip literal character */ - if (bp == errtoken) continue; /* skip error token */ - if ('\"' == *symbol) - { - /* use literal string only if given a symbol with an alias */ - if (bp->alias) - symbol = bp->alias->tag; - else - continue; - } - /* Don't #define nonliteral tokens whose names contain periods. */ - 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); - } +static void +prepare_percent_define_front_end_variables (void) +{ + /* Set %define front-end variable defaults. */ + muscle_percent_define_default ("lr.keep-unreachable-states", "false"); + { + char *lr_type; + /* IELR would be a better default, but LALR is historically the + default. */ + muscle_percent_define_default ("lr.type", "lalr"); + lr_type = muscle_percent_define_get ("lr.type"); + if (0 != strcmp (lr_type, "canonical-lr")) + muscle_percent_define_default ("lr.default-reductions", "all"); + else + muscle_percent_define_default ("lr.default-reductions", "accepting"); + free (lr_type); + } - putc('\n', file); + /* Check %define front-end variables. */ + { + static char const * const values[] = { + "lr.type", "lalr", "ielr", "canonical-lr", NULL, + "lr.default-reductions", "all", "consistent", "accepting", NULL, + NULL + }; + muscle_percent_define_check_values (values); + } } +/*-------------------------------------------------------------. +| Check the grammar that has just been read, and convert it to | +| internal form. | +`-------------------------------------------------------------*/ -/* convert the rules into the representation using rrhs, rlhs and ritems. */ - -void -packgram() +static void +check_and_convert_grammar (void) { - register int itemno; - register int ruleno; - register symbol_list *p; -/* register bucket *bp; JF unused */ - - bucket *ruleprec; - - 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; + /* Grammar has been read. Do some checking. */ + if (nrules == 0) + fatal (_("no rules in the input grammar")); - p = grammar; - while (p) + /* If the user did not define her ENDTOKEN, do it now. */ + if (!endtoken) { - 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; - } - - ritem[itemno++] = -ruleno; - ruleno++; - - if (p) p = p->next; + endtoken = symbol_get ("$end", empty_location); + endtoken->class = token_sym; + endtoken->number = 0; + /* Value specified by POSIX. */ + endtoken->user_token_number = 0; } - ritem[itemno] = 0; -} - -/* Read a signed integer from STREAM and return its value. */ - -int -read_signed_integer (stream) - FILE *stream; -{ - register int c = getc(stream); - register int sign = 1; - register int n; + /* Report any undefined symbols and consider them nonterminals. */ + symbols_check_defined (); - if (c == '-') - { - c = getc(stream); - sign = -1; - } - n = 0; - while (isdigit(c)) + /* Find the start symbol if no %start. */ + if (!start_flag) { - n = 10*n + (c - '0'); - c = getc(stream); + symbol_list *node; + for (node = grammar; + node != NULL && symbol_is_dummy (node->content.sym); + node = node->next) + { + for (node = node->next; + node != NULL && node->content.sym != NULL; + node = node->next) + ; + } + aver (node != NULL); + grammar_start_symbol_set (node->content.sym, + node->content.sym->location); } - ungetc(c, stream); + /* Insert the initial rule, whose line is that of the first rule + (not that of the start symbol): + + accept: %start EOF. */ + { + symbol_list *p = symbol_list_sym_new (accept, empty_location); + p->location = grammar->location; + p->next = symbol_list_sym_new (startsymbol, empty_location); + p->next->next = symbol_list_sym_new (endtoken, empty_location); + p->next->next->next = symbol_list_sym_new (NULL, empty_location); + p->next->next->next->next = grammar; + nrules += 1; + nritems += 3; + grammar = p; + } + + aver (nsyms <= SYMBOL_NUMBER_MAXIMUM && nsyms == ntokens + nvars); + + /* Assign the symbols their symbol numbers. Write #defines for the + token symbols into FDEFINES if requested. */ + symbols_pack (); + + /* Scan rule actions after invoking symbol_check_alias_consistency (in + symbols_pack above) so that token types are set correctly before the rule + action type checking. + + Before invoking grammar_rule_check (in packgram below) on any rule, make + sure all actions have already been scanned in order to set `used' flags. + Otherwise, checking that a midrule's $$ should be set will not always work + properly because the check must forward-reference the midrule's parent + rule. For the same reason, all the `used' flags must be set before + checking whether to remove `$' from any midrule symbol name (also in + packgram). */ + { + symbol_list *sym; + for (sym = grammar; sym; sym = sym->next) + code_props_translate_code (&sym->action_props); + } + + /* Convert the grammar into the format described in gram.h. */ + packgram (); - return n * sign; + /* The grammar as a symbol_list is no longer needed. */ + symbol_list_free (grammar); }