X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/eb095650011f68858e877e3590f6901bc79ba668..bcd80897f3b414973fc34dc2ec57ce4df2e69253:/src/scan-code.h diff --git a/src/scan-code.h b/src/scan-code.h index f2d79720..348d9e3f 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, 2009-2012 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 +15,182 @@ 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 . */ #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. + * 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; -/* The action of the rule R contains $$, $1 etc. referring to the values - of the rule R. */ -char const *translate_rule_action (symbol_list *r); +/** + * \pre + * - self != NULL. + * \post + * - \c self has been overwritten to contain no code. + */ +void code_props_none_init (code_props *self); -/* The action A refers to $$ and @$ only, referring to a symbol. */ -char const *translate_symbol_action (char const *a, location l); +/** 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 \ + } -/* The action contains no special escapes, just protect M4 special - symbols. */ -char const *translate_code (char const *a, location l); +/** Initialized by \c CODE_PROPS_NONE_INIT with no further modification. */ +extern code_props code_props_none; + +/** + * \pre + * - self != NULL. + * - code != NULL. + * - \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 + * - self != NULL. + * - code != NULL. + * - \c code is an untranslated code passage. The only Bison escapes it + * might contain are $$ and \@$, referring to a single symbol. + * - \c code was extracted from the grammar file at \c code_loc. + * \post + * - \c self has been overwritten to represent the specified symbol action. + * - \c self will become invalid if the caller frees \c code before invoking + * \c code_props_translate_code on \c self. + */ +void code_props_symbol_action_init (code_props *self, char const *code, + location code_loc); + +/** + * \pre + * - self != NULL. + * - code != NULL. + * - rule != NULL. + * - \c code is the untranslated action of the rule for which \c rule is the + * LHS node. Thus, \c code possibly contains Bison escapes such as $$, $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. + * - self->code != self->code\@pre unless + * self->code\@pre = NULL. + */ +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_ */