mirror of
https://git.savannah.gnu.org/git/bison.git
synced 2026-03-10 04:43:03 +00:00
Encapsulate code properties and related functionality for the various
destructors, printers, and actions into a code_props structure and interface. This patch merely implements code_props in scan-code.h and scan-code.l. Future patches will rewrite other modules to use it. Discussed starting at <http://lists.gnu.org/archive/html/bison-patches/2006-11/msg00020.html>. * src/location.h (EMPTY_LOCATION_INIT): Define so that it's easier to consistently initialize const structs that have an empty location field. * src/location.c (empty_location): Initialize with EMPTY_LOCATION_INIT to ensure consistency. * src/scan-code.h (code_props): New structure. (code_props_none_init, CODE_PROPS_NONE_INIT, code_props_none): New function, macro, and const global variable for initializing a code_props with no code. (code_props_plain_init, code_props_symbol_action_init, code_props_rule_action_init, code_props_translate_code): The rest of the new code_props functional interface. Among other things, the init functions set the code_props kind field so that code_props_translate_code will know whether to behave like translate_symbol_action, translate_rule_action, or translate_code. These old translate functions must remain until all other modules are updated to use the new code_props interface. (code_scanner_last_string_free): New function similar to gram_scanner_last_string_free. (code_scanner_free): Add documentation. * src/scan-code.l: Implement the new interface. (code_lex): Make it static, add a code_props* argument, and remove the rule argument. (last_string): New static global similar to the one in scan-gram.l. (SC_RULE_ACTION): Update to use the code_props* argument to code_lex instead of rule. (SC_SYMBOL_ACTION): For $$, set the is_value_used member of the code_props since Bison may one day use this information for destructors and printers. (<*><<EOF>>): Use STRING_FINISH so that last_string is set. (handle_action_dollar): Use symbol_list_n_get and set used flag directly since symbol_list_n_used_set is removed. (translate_action): Add a code_props* argument and remove the rule, action, and location arguments. Pass the code_props* on to code_lex. (translate_rule_action, translate_symbol_action, translate_code): Rewrite as wrappers around the new code_props interface. * src/symlist.h, src/symlist.c (symbol_list_n_used_set): Remove since it would eventually need to break the encapsulation of code_props.
This commit is contained in:
Joel E. Denny
148
src/scan-code.h
148
src/scan-code.h
@@ -1,6 +1,6 @@
|
||||
/* Bison Action Scanner
|
||||
/* Bison code properties structure and scanner.
|
||||
|
||||
Copyright (C) 2006 Free Software Foundation, Inc.
|
||||
Copyright (C) 2006, 2007 Free Software Foundation, Inc.
|
||||
|
||||
This file is part of Bison, the GNU Compiler Compiler.
|
||||
|
||||
@@ -24,13 +24,149 @@
|
||||
# define SCAN_CODE_H_
|
||||
|
||||
# include "location.h"
|
||||
# include "symlist.h"
|
||||
|
||||
/* Keeps track of the maximum number of semantic values to the left of
|
||||
a handle (those referenced by $0, $-1, etc.) are required by the
|
||||
semantic actions of this grammar. */
|
||||
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. */
|
||||
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 NULL iff \c code_props::kind is not \c CODE_PROPS_RULE_ACTION. */
|
||||
struct symbol_list *rule;
|
||||
} 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 \
|
||||
{CODE_PROPS_NONE, NULL, EMPTY_LOCATION_INIT, false, NULL}
|
||||
|
||||
/** Initialized by \c CODE_PROPS_NONE_INIT with no further modification. */
|
||||
extern code_props const 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 $$, $1,
|
||||
* $2, etc referring to the values of the rule.
|
||||
* - \c code was extracted from the grammar file at \c code_loc.
|
||||
* \post
|
||||
* - \c self has been overwritten to represent the specified rule action.
|
||||
* - \c self does not claim responsibility for the memory of \c rule.
|
||||
* - \c self will become invalid if:
|
||||
* - The caller frees \c code before invoking \c code_props_translate_code
|
||||
* on \c self.
|
||||
* - The caller frees \c rule.
|
||||
*/
|
||||
void code_props_rule_action_init (code_props *self, char const *code,
|
||||
location code_loc, struct symbol_list *rule);
|
||||
|
||||
/**
|
||||
* \pre
|
||||
* - If there's a code passage contained in \c self and it contains Bison
|
||||
* escapes, all grammar declarations have already been parsed as they may
|
||||
* affect warnings and complaints issued here.
|
||||
* \post
|
||||
* - All M4-special symbols and Bison escapes have been translated in
|
||||
* \c self->code.
|
||||
* - <tt>self->code != self->code\@pre</tt> unless
|
||||
* <tt>self->code\@pre = NULL</tt>.
|
||||
*/
|
||||
void code_props_translate_code (code_props *self);
|
||||
|
||||
/**
|
||||
* \pre
|
||||
* - None.
|
||||
* \post
|
||||
* - The dynamic memory allocated by the previous invocation of
|
||||
* \c code_props_translate_code (if any) was freed. The \c code_props
|
||||
* instance for which \c code_props_translate_code was invoked is now
|
||||
* invalid.
|
||||
*/
|
||||
void code_scanner_last_string_free (void);
|
||||
|
||||
/**
|
||||
* \pre
|
||||
* - None.
|
||||
* \post
|
||||
* - All dynamic memory allocated during any previous invocations of
|
||||
* \c code_props_translate_code, \c translate_rule_action,
|
||||
* \c translate_symbol_action, and \c translate_code has been freed. All
|
||||
* \c code_props instances may now be invalid.
|
||||
*/
|
||||
void code_scanner_free (void);
|
||||
|
||||
/* The action of the rule R contains $$, $1 etc. referring to the values
|
||||
|
||||
Reference in New Issue
Block a user