X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/e9071366c3104e4e4a2490c16d53e7eeef670f45..d67e37a74bc91e2fe254e5b7a28c62537a20e206:/src/scan-code.h

diff --git a/src/scan-code.h b/src/scan-code.h
index 8d979357..a2942a07 100644
--- a/src/scan-code.h
+++ b/src/scan-code.h
@@ -1,12 +1,12 @@
-/* Bison Action Scanner
+/* Bison code properties structure and scanner.
 
-   Copyright (C) 2006 Free Software Foundation, Inc.
+   Copyright (C) 2006-2007, 2009-2010 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
+   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 2 of the License, or
+   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,
@@ -15,33 +15,159 @@
    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, write to the Free Software
-   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
-   02110-1301  USA
-*/
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #ifndef SCAN_CODE_H_
 # define SCAN_CODE_H_
 
 # include "location.h"
-# include "symlist.h"
+# include "named-ref.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;
 
-void code_scanner_free (void);
+/**
+ * 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;
+
+  /* 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);
 
-/* The action A contains $$, $1 etc. referring to the values
-   of the rule R. */
-const char *translate_rule_action (symbol_list *r, const char *a, location l);
+/** Equivalent to \c code_props_none_init.  */
+#define CODE_PROPS_NONE_INIT \
+  {CODE_PROPS_NONE, NULL, EMPTY_LOCATION_INIT, false, NULL, NULL}
 
-/* The action A refers to $$ and @$ only, referring to a symbol. */
-const char *translate_symbol_action (const char *a, location l);
+/** Initialized by \c CODE_PROPS_NONE_INIT with no further modification.  */
+extern code_props const code_props_none;
 
-/* The action contains no special escapes, just protect M4 special
-   symbols.  */
-const char *translate_code (const char *a, location l);
+/**
+ * \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);
+
+/**
+ * \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_ */