+2007-01-02 Joel E. Denny <jdenny@ces.clemson.edu>
+
+ 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.
+
2007-01-01 Joel E. Denny <jdenny@ces.clemson.edu>
* etc/.cvsignore: New.
/* Locations for Bison
- Copyright (C) 2002, 2005, 2006 Free Software Foundation, Inc.
+ Copyright (C) 2002, 2005, 2006, 2007 Free Software Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
#include "complain.h"
#include "location.h"
-location const empty_location;
+location const empty_location = EMPTY_LOCATION_INIT;
/* If BUF is null, add BUFSIZE (which in this case must be less than
INT_MAX) to COLUMN; otherwise, add mbsnwidth (BUF, BUFSIZE, 0) to
/* Locations for Bison
- Copyright (C) 2002, 2004, 2005, 2006 Free Software Foundation, Inc.
+ Copyright (C) 2002, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
#define YYLTYPE location
+#define EMPTY_LOCATION_INIT {{NULL, 0, 0}, {NULL, 0, 0}}
extern location const empty_location;
/* Set *LOC and adjust scanner cursor to account for token TOKEN of
-/* 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.
# 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
/* Bison Action Scanner -*- C -*-
- 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.
#include <quote.h>
#include "scan-code.h"
+#include "symlist.h"
/* The current calling start condition: SC_RULE_ACTION or
SC_SYMBOL_ACTION. */
-# define YY_DECL char *code_lex (int sc_context, symbol_list *rule)
+# define YY_DECL static char *code_lex (code_props *self, int sc_context)
YY_DECL;
#define YY_USER_ACTION location_compute (loc, &loc->end, yytext, yyleng);
static location the_location;
static location *loc = &the_location;
+/* A string representing the most recent translation. */
+static char *last_string;
+
/* True if an untyped $$ or $n was seen. */
static bool untyped_var_seen;
%}
<SC_RULE_ACTION>
{
- "$"("<"{tag}">")?(-?[0-9]+|"$") handle_action_dollar (rule, yytext, *loc);
- "@"(-?[0-9]+|"$") handle_action_at (rule, yytext, *loc);
+ "$"("<"{tag}">")?(-?[0-9]+|"$") {
+ handle_action_dollar (self->rule, yytext, *loc);
+ }
+ "@"(-?[0-9]+|"$") {
+ handle_action_at (self->rule, yytext, *loc);
+ }
"$" {
warn_at (*loc, _("stray `$'"));
<SC_SYMBOL_ACTION>
{
- "$$" obstack_sgrow (&obstack_for_string, "]b4_dollar_dollar[");
+ "$$" {
+ obstack_sgrow (&obstack_for_string, "]b4_dollar_dollar[");
+ self->is_value_used = true;
+ }
"@$" obstack_sgrow (&obstack_for_string, "]b4_at_dollar[");
}
/* End of processing. */
<*><<EOF>> {
- obstack_1grow (&obstack_for_string, '\0');
- return obstack_finish (&obstack_for_string);
+ STRING_FINISH;
+ return last_string;
}
%%
static void
handle_action_dollar (symbol_list *rule, char *text, location dollar_loc)
{
- const char *type_name = NULL;
+ char const *type_name = NULL;
char *cp = text + 1;
symbol_list *effective_rule;
int effective_rule_length;
obstack_fgrow3 (&obstack_for_string,
"]b4_rhs_value(%d, %d, [%s])[",
effective_rule_length, n, type_name);
- symbol_list_n_used_set (effective_rule, n, true);
+ if (n > 0)
+ symbol_list_n_get (effective_rule, n)->used = true;
}
else
complain_at (dollar_loc, _("integer out of range: %s"), quote (text));
| Initialize the scanner. |
`-------------------------*/
-/* Translate the dollars and ats in \a a, whose location is \a l. The
- translation is for \a rule, in the context \a sc_context
+/* Translate the dollars and ats in \a self, in the context \a sc_context
(SC_RULE_ACTION, SC_SYMBOL_ACTION, INITIAL). */
static char const *
-translate_action (int sc_context, symbol_list *rule, char const *a, location l)
+translate_action (code_props *self, int sc_context)
{
char *res;
static bool initialized = false;
initialized = true;
}
- loc->start = loc->end = l.start;
- yy_switch_to_buffer (yy_scan_string (a));
- res = code_lex (sc_context, rule);
+ loc->start = loc->end = self->location.start;
+ yy_switch_to_buffer (yy_scan_string (self->code));
+ res = code_lex (self, sc_context);
yy_delete_buffer (YY_CURRENT_BUFFER);
return res;
}
-char const *
-translate_rule_action (symbol_list *rule)
+/*------------------------------------------------------------------------.
+| Implementation of the public interface as documented in "scan-code.h". |
+`------------------------------------------------------------------------*/
+
+void
+code_props_none_init (code_props *self)
{
- return translate_action (SC_RULE_ACTION, rule, rule->action,
- rule->action_location);
+ *self = code_props_none;
}
-char const *
-translate_symbol_action (char const *a, location l)
+code_props const code_props_none = CODE_PROPS_NONE_INIT;
+
+void
+code_props_plain_init (code_props *self, char const *code, location code_loc)
{
- return translate_action (SC_SYMBOL_ACTION, NULL, a, l);
+ self->kind = CODE_PROPS_PLAIN;
+ self->code = code;
+ self->location = code_loc;
+ self->is_value_used = false;
+ self->rule = NULL;
}
-char const *
-translate_code (char const *a, location l)
+void
+code_props_symbol_action_init (code_props *self, char const *code,
+ location code_loc)
{
- return translate_action (INITIAL, NULL, a, l);
+ self->kind = CODE_PROPS_SYMBOL_ACTION;
+ self->code = code;
+ self->location = code_loc;
+ self->is_value_used = false;
+ self->rule = NULL;
}
-/*-----------------------------------------------.
-| Free all the memory allocated to the scanner. |
-`-----------------------------------------------*/
+void
+code_props_rule_action_init (code_props *self, char const *code,
+ location code_loc, symbol_list *rule)
+{
+ self->kind = CODE_PROPS_RULE_ACTION;
+ self->code = code;
+ self->location = code_loc;
+ self->is_value_used = false;
+ self->rule = rule;
+}
+
+void
+code_props_translate_code (code_props *self)
+{
+ switch (self->kind)
+ {
+ case CODE_PROPS_NONE:
+ break;
+ case CODE_PROPS_PLAIN:
+ self->code = translate_action (self, INITIAL);
+ break;
+ case CODE_PROPS_SYMBOL_ACTION:
+ self->code = translate_action (self, SC_SYMBOL_ACTION);
+ break;
+ case CODE_PROPS_RULE_ACTION:
+ self->code = translate_action (self, SC_RULE_ACTION);
+ break;
+ }
+}
+
+void
+code_scanner_last_string_free (void)
+{
+ STRING_FREE;
+}
void
code_scanner_free (void)
/* Reclaim Flex's buffers. */
yylex_destroy ();
}
+
+char const *
+translate_rule_action (symbol_list *rule)
+{
+ code_props cp;
+ code_props_rule_action_init (&cp, rule->action, rule->action_location, rule);
+ code_props_translate_code (&cp);
+ return cp.code;
+}
+
+char const *
+translate_symbol_action (char const *a, location l)
+{
+ code_props cp;
+ code_props_symbol_action_init (&cp, a, l);
+ code_props_translate_code (&cp);
+ return cp.code;
+}
+
+char const *
+translate_code (char const *a, location l)
+{
+ code_props cp;
+ code_props_plain_init (&cp, a, l);
+ code_props_translate_code (&cp);
+ return cp.code;
+}
/* Lists of symbols for Bison
- Copyright (C) 2002, 2005, 2006 Free Software Foundation, Inc.
+ Copyright (C) 2002, 2005, 2006, 2007 Free Software Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
}
-/*--------------------------------------.
-| The item N in symbol list L is USED. |
-`--------------------------------------*/
-
-void
-symbol_list_n_used_set (symbol_list *l, int n, bool used)
-{
- l = symbol_list_n_get (l, n);
- if (l)
- l->used = used;
-}
-
void
symbol_list_destructor_set (symbol_list *node, const char *destructor,
location loc)
/* Lists of symbols for Bison
- Copyright (C) 2002, 2005, 2006 Free Software Foundation, Inc.
+ Copyright (C) 2002, 2005, 2006, 2007 Free Software Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
symbol N in rule RULE. */
uniqstr symbol_list_n_type_name_get (symbol_list *l, location loc, int n);
-/** The item \c n in symbol list \c l is \c used. */
-void symbol_list_n_used_set (symbol_list *l, int n, bool used);
-
/** Set the \c \%destructor for \c node as \c destructor at \c loc. */
void symbol_list_destructor_set (symbol_list *node, const char *destructor,
location loc);
projects / bison.git / commitdiff
