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Unified Diff: bison/src/bison/2.4.1/bison-2.4.1-src/src/reader.c

Issue 10807020: Add native Windows binary for bison. (Closed) Base URL: svn://chrome-svn/chrome/trunk/deps/third_party/
Patch Set: Created 8 years, 5 months ago
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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 (&current_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 (&current_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
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