Index: bison/src/bison/2.4.1/bison-2.4.1-src/src/reader.c |
=================================================================== |
--- bison/src/bison/2.4.1/bison-2.4.1-src/src/reader.c (revision 0) |
+++ bison/src/bison/2.4.1/bison-2.4.1-src/src/reader.c (revision 0) |
@@ -0,0 +1,652 @@ |
+/* Input parser for Bison |
+ |
+ Copyright (C) 1984, 1986, 1989, 1992, 1998, 2000, 2001, 2002, 2003, |
+ 2005, 2006, 2007 Free Software Foundation, Inc. |
+ |
+ This file is part of Bison, the GNU Compiler Compiler. |
+ |
+ This program is free software: you can redistribute it and/or modify |
+ it under the terms of the GNU General Public License as published by |
+ the Free Software Foundation, either version 3 of the License, or |
+ (at your option) any later version. |
+ |
+ This program is distributed in the hope that it will be useful, |
+ but WITHOUT ANY WARRANTY; without even the implied warranty of |
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
+ GNU General Public License for more details. |
+ |
+ You should have received a copy of the GNU General Public License |
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
+ |
+#include <config.h> |
+#include "system.h" |
+ |
+#include <quotearg.h> |
+ |
+#include "complain.h" |
+#include "conflicts.h" |
+#include "files.h" |
+#include "getargs.h" |
+#include "gram.h" |
+#include "muscle_tab.h" |
+#include "reader.h" |
+#include "symlist.h" |
+#include "symtab.h" |
+#include "scan-gram.h" |
+#include "scan-code.h" |
+ |
+static void check_and_convert_grammar (void); |
+ |
+static symbol_list *grammar = NULL; |
+static bool start_flag = false; |
+merger_list *merge_functions; |
+ |
+/* Was %union seen? */ |
+bool union_seen = false; |
+ |
+/* Was a tag seen? */ |
+bool tag_seen = false; |
+ |
+/* Should rules have a default precedence? */ |
+bool default_prec = true; |
+ |
+/*-----------------------. |
+| Set the start symbol. | |
+`-----------------------*/ |
+ |
+void |
+grammar_start_symbol_set (symbol *sym, location loc) |
+{ |
+ if (start_flag) |
+ complain_at (loc, _("multiple %s declarations"), "%start"); |
+ else |
+ { |
+ start_flag = true; |
+ startsymbol = sym; |
+ startsymbol_location = loc; |
+ } |
+} |
+ |
+ |
+ |
+/*------------------------------------------------------------------------. |
+| Return the merger index for a merging function named NAME. Records the | |
+| function, if new, in MERGER_LIST. | |
+`------------------------------------------------------------------------*/ |
+ |
+static int |
+get_merge_function (uniqstr name) |
+{ |
+ 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) |
+ { |
+ 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; |
+} |
+ |
+/*-------------------------------------------------------------------------. |
+| 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. | |
+`-------------------------------------------------------------------------*/ |
+ |
+static void |
+record_merge_function_type (int merger, uniqstr type, location declaration_loc) |
+{ |
+ 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)) |
+ { |
+ 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")); |
+ } |
+ merge_function->type = uniqstr_new (type); |
+ merge_function->type_declaration_location = declaration_loc; |
+} |
+ |
+/*--------------------------------------. |
+| Free all merge-function definitions. | |
+`--------------------------------------*/ |
+ |
+void |
+free_merger_functions (void) |
+{ |
+ merger_list *L0 = merge_functions; |
+ while (L0) |
+ { |
+ merger_list *L1 = L0->next; |
+ free (L0); |
+ L0 = L1; |
+ } |
+} |
+ |
+ |
+/*-------------------------------------------------------------------. |
+| 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 void |
+grammar_symbol_append (symbol *sym, location loc) |
+{ |
+ symbol_list *p = symbol_list_sym_new (sym, loc); |
+ |
+ if (grammar_end) |
+ grammar_end->next = p; |
+ else |
+ grammar = p; |
+ |
+ grammar_end = p; |
+ |
+ /* A null SYM stands for an end of rule; it is not an actual |
+ part of it. */ |
+ if (sym) |
+ ++nritems; |
+} |
+ |
+/* 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; |
+ |
+ |
+/*----------------------------------------------. |
+| Create a new rule for LHS in to the GRAMMAR. | |
+`----------------------------------------------*/ |
+ |
+void |
+grammar_current_rule_begin (symbol *lhs, location loc) |
+{ |
+ /* Start a new rule and record its lhs. */ |
+ ++nrules; |
+ previous_rule_end = grammar_end; |
+ grammar_symbol_append (lhs, loc); |
+ current_rule = grammar_end; |
+ |
+ /* Mark the rule's lhs as a nonterminal if not already so. */ |
+ if (lhs->class == unknown_sym) |
+ { |
+ 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); |
+} |
+ |
+ |
+/*----------------------------------------------------------------------. |
+| 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; }". | |
+`----------------------------------------------------------------------*/ |
+ |
+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; |
+} |
+ |
+/*----------------------------------------------------------------. |
+| Check that the rule R is properly defined. For instance, there | |
+| should be no type clash on the default action. | |
+`----------------------------------------------------------------*/ |
+ |
+static void |
+grammar_rule_check (const symbol_list *r) |
+{ |
+ /* Type check. |
+ |
+ If there is an action, then there is nothing we can do: the user |
+ is allowed to shoot herself in the foot. |
+ |
+ 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) |
+ { |
+ symbol *first_rhs = r->next->content.sym; |
+ /* If $$ is being set in default way, report if any type mismatch. */ |
+ if (first_rhs) |
+ { |
+ char const *lhs_type = r->content.sym->type_name; |
+ const char *rhs_type = |
+ first_rhs->type_name ? first_rhs->type_name : ""; |
+ if (!UNIQSTR_EQ (lhs_type, rhs_type)) |
+ warn_at (r->location, |
+ _("type clash on default action: <%s> != <%s>"), |
+ lhs_type, rhs_type); |
+ } |
+ /* Warn if there is no default for $$ but we need one. */ |
+ else |
+ warn_at (r->location, |
+ _("empty rule for typed nonterminal, and no action")); |
+ } |
+ |
+ /* 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, $$ = $1, `uses' both. */ |
+ || (!r->action_props.code && (n == 0 || n == 1)))) |
+ { |
+ if (n) |
+ warn_at (r->location, _("unused value: $%d"), n); |
+ else |
+ warn_at (r->location, _("unset value: $$")); |
+ } |
+ } |
+} |
+ |
+ |
+/*-------------------------------------. |
+| End the currently being grown rule. | |
+`-------------------------------------*/ |
+ |
+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; |
+} |
+ |
+ |
+/*-------------------------------------------------------------------. |
+| 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 |
+grammar_midrule_action (void) |
+{ |
+ /* 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); |
+ |
+ /* 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); |
+ code_props_none_init (¤t_rule->action_props); |
+ |
+ if (previous_rule_end) |
+ previous_rule_end->next = midrule; |
+ else |
+ grammar = midrule; |
+ |
+ /* End the dummy's rule. */ |
+ midrule->next = symbol_list_sym_new (NULL, dummy_location); |
+ midrule->next->next = current_rule; |
+ |
+ previous_rule_end = midrule->next; |
+ |
+ /* 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); |
+ 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. */ |
+ |
+void |
+grammar_current_rule_prec_set (symbol *precsym, location loc) |
+{ |
+ 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; |
+} |
+ |
+/* Attach dynamic precedence DPREC to the current rule. */ |
+ |
+void |
+grammar_current_rule_dprec_set (int dprec, location loc) |
+{ |
+ 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 |
+grammar_current_rule_merge_set (uniqstr name, location loc) |
+{ |
+ 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. */ |
+ |
+void |
+grammar_current_rule_symbol_append (symbol *sym, location loc) |
+{ |
+ if (current_rule->action_props.code) |
+ grammar_midrule_action (); |
+ grammar_symbol_append (sym, loc); |
+} |
+ |
+/* Attach an ACTION to the current rule. */ |
+ |
+void |
+grammar_current_rule_action_append (const char *action, location loc) |
+{ |
+ 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); |
+} |
+ |
+ |
+/*---------------------------------------------------------------. |
+| Convert the rules into the representation using RRHS, RLHS and | |
+| RITEM. | |
+`---------------------------------------------------------------*/ |
+ |
+static void |
+packgram (void) |
+{ |
+ unsigned int itemno = 0; |
+ rule_number ruleno = 0; |
+ symbol_list *p = grammar; |
+ |
+ ritem = xnmalloc (nritems + 1, sizeof *ritem); |
+ |
+ /* This sentinel is used by build_relations in gram.c. */ |
+ *ritem++ = 0; |
+ |
+ rules = xnmalloc (nrules, sizeof *rules); |
+ |
+ while (p) |
+ { |
+ 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) |
+ { |
+ ++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 this rule has a %prec, |
+ the specified symbol's precedence replaces the default. */ |
+ if (ruleprec) |
+ { |
+ rules[ruleno].precsym = ruleprec; |
+ rules[ruleno].prec = ruleprec; |
+ } |
+ /* 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; |
+ } |
+ |
+ aver (itemno == nritems); |
+ |
+ 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. | |
+`------------------------------------------------------------------*/ |
+ |
+void |
+reader (void) |
+{ |
+ /* 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++; |
+ |
+ gram_in = xfopen (grammar_file, "r"); |
+ |
+ gram__flex_debug = trace_flag & trace_scan; |
+ gram_debug = trace_flag & trace_parse; |
+ gram_scanner_initialize (); |
+ gram_parse (); |
+ |
+ if (! complaint_issued) |
+ check_and_convert_grammar (); |
+ |
+ xfclose (gram_in); |
+} |
+ |
+ |
+/*-------------------------------------------------------------. |
+| Check the grammar that has just been read, and convert it to | |
+| internal form. | |
+`-------------------------------------------------------------*/ |
+ |
+static void |
+check_and_convert_grammar (void) |
+{ |
+ /* Grammar has been read. Do some checking. */ |
+ if (nrules == 0) |
+ fatal (_("no rules in the input grammar")); |
+ |
+ /* Report any undefined symbols and consider them nonterminals. */ |
+ symbols_check_defined (); |
+ |
+ /* If the user did not define her ENDTOKEN, do it now. */ |
+ if (!endtoken) |
+ { |
+ endtoken = symbol_get ("$end", empty_location); |
+ endtoken->class = token_sym; |
+ endtoken->number = 0; |
+ /* Value specified by POSIX. */ |
+ endtoken->user_token_number = 0; |
+ } |
+ |
+ /* Find the start symbol if no %start. */ |
+ if (!start_flag) |
+ { |
+ 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); |
+ } |
+ |
+ /* 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 (); |
+ |
+ /* The grammar as a symbol_list is no longer needed. */ |
+ symbol_list_free (grammar); |
+} |
Property changes on: bison\src\bison\2.4.1\bison-2.4.1-src\src\reader.c |
___________________________________________________________________ |
Added: svn:eol-style |
+ LF |