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/* Bison code properties structure and scanner.
Copyright (C) 2006-2007, 2009-2013 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/>. */
#ifndef SCAN_CODE_H_
# define SCAN_CODE_H_
# include "location.h"
# include "named-ref.h"
struct symbol_list;
/**
* Keeps track of the maximum number of semantic values to the left of a handle
* (those referenced by $0, $-1, etc.) that are required by the semantic
* actions of this grammar.
*/
extern int max_left_semantic_context;
/**
* A code passage captured from the grammar file and possibly translated,
* and/or properties associated with such a code passage. Don't break
* encapsulation by modifying the fields directly. Use the provided interface
* functions.
*/
typedef struct code_props {
/** Set by the init functions. */
enum {
CODE_PROPS_NONE, CODE_PROPS_PLAIN,
CODE_PROPS_SYMBOL_ACTION, CODE_PROPS_RULE_ACTION
} kind;
/**
* \c NULL iff \c code_props::kind is \c CODE_PROPS_NONE.
* Memory is allocated in an obstack freed elsewhere.
*/
char const *code;
/** Undefined iff \c code_props::code is \c NULL. */
location location;
/**
* \c false iff either:
* - \c code_props_translate_code has never previously been invoked for
* the \c code_props that would contain the code passage associated
* with \c self. (That \c code_props is not the same as this one if this
* one is for a RHS \c symbol_list node. Instead, it's the \c code_props
* for the LHS symbol of the same rule.)
* - \c code_props_translate_code has been invoked for that \c code_props,
* but the symbol value associated with this \c code_props was not
* referenced in the code passage.
*/
bool is_value_used;
/**
* \c true iff this code is an action that is not to be deferred in
* a non-deterministic parser.
*/
bool is_predicate;
/**
* Whether this is actually used (i.e., not completely masked by
* other code props). */
bool is_used;
/** \c NULL iff \c code_props::kind is not \c CODE_PROPS_RULE_ACTION. */
struct symbol_list *rule;
/* Named reference. */
named_ref *named_ref;
} code_props;
/**
* \pre
* - <tt>self != NULL</tt>.
* \post
* - \c self has been overwritten to contain no code.
*/
void code_props_none_init (code_props *self);
/** Equivalent to \c code_props_none_init. */
# define CODE_PROPS_NONE_INIT \
{ \
/* .kind = */ CODE_PROPS_NONE, \
/* .code = */ NULL, \
/* .location = */ EMPTY_LOCATION_INIT, \
/* .is_value_used = */ false, \
/* .is_predicate = */ false, \
/* .is_used = */ false, \
/* .rule = */ NULL, \
/* .named_ref = */ NULL \
}
/** Initialized by \c CODE_PROPS_NONE_INIT with no further modification. */
extern code_props code_props_none;
/**
* \pre
* - <tt>self != NULL</tt>.
* - <tt>code != NULL</tt>.
* - \c code is an untranslated code passage containing no Bison escapes.
* - \c code was extracted from the grammar file at \c code_loc.
* \post
* - \c self has been overwritten to represent the specified plain code
* passage.
* - \c self will become invalid if the caller frees \c code before invoking
* \c code_props_translate_code on \c self.
*/
void code_props_plain_init (code_props *self, char const *code,
location code_loc);
/**
* \pre
* - <tt>self != NULL</tt>.
* - <tt>code != NULL</tt>.
* - \c code is an untranslated code passage. The only Bison escapes it
* might contain are $$ and \@$, referring to a single symbol.
* - \c code was extracted from the grammar file at \c code_loc.
* \post
* - \c self has been overwritten to represent the specified symbol action.
* - \c self will become invalid if the caller frees \c code before invoking
* \c code_props_translate_code on \c self.
*/
void code_props_symbol_action_init (code_props *self, char const *code,
location code_loc);
/**
* \pre
* - <tt>self != NULL</tt>.
* - <tt>code != NULL</tt>.
* - <tt>rule != NULL</tt>.
* - \c code is the untranslated action of the rule for which \c rule is the
* LHS node. Thus, \c code possibly contains Bison escapes such as $$, $1,
* $2, etc referring to the values of the rule.
* - \c code was extracted from the grammar file at \c code_loc.
* \post
* - \c self has been overwritten to represent the specified rule action.
* - \c self does not claim responsibility for the memory of \c rule.
* - \c self will become invalid if:
* - The caller frees \c code before invoking \c code_props_translate_code
* on \c self.
* - The caller frees \c rule.
*/
void code_props_rule_action_init (code_props *self, char const *code,
location code_loc, struct symbol_list *rule,
named_ref *name, bool is_predicate);
/**
* \pre
* - If there's a code passage contained in \c self and it contains Bison
* escapes, all grammar declarations have already been parsed as they may
* affect warnings and complaints issued here.
* \post
* - All M4-special symbols and Bison escapes have been translated in
* \c self->code.
* - <tt>self->code != self->code\@pre</tt> unless
* <tt>self->code\@pre = NULL</tt>.
*/
void code_props_translate_code (code_props *self);
/**
* \pre
* - None.
* \post
* - The dynamic memory allocated by the previous invocation of
* \c code_props_translate_code (if any) was freed. The \c code_props
* instance for which \c code_props_translate_code was invoked is now
* invalid.
*/
void code_scanner_last_string_free (void);
/**
* \pre
* - None.
* \post
* - All dynamic memory allocated during invocations of
* \c code_props_translate_code (if any) has been freed. All \c code_props
* instances may now be invalid.
*/
void code_scanner_free (void);
#endif /* !SCAN_CODE_H_ */
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