diff options
Diffstat (limited to 'include/ruby/internal/symbol.h')
| -rw-r--r-- | include/ruby/internal/symbol.h | 75 |
1 files changed, 43 insertions, 32 deletions
diff --git a/include/ruby/internal/symbol.h b/include/ruby/internal/symbol.h index 869a31115c..8bfd686fbe 100644 --- a/include/ruby/internal/symbol.h +++ b/include/ruby/internal/symbol.h @@ -101,12 +101,11 @@ ID rb_intern(const char *name); ID rb_intern2(const char *name, long len); /** - * Identical to rb_intern(), except it takes an instance of ::rb_cString. + * Identical to rb_intern(), except it takes a `T_STRING` object. * * @param[in] str The name of the id. - * @pre `str` must either be an instance of ::rb_cSymbol, or an instance - * of ::rb_cString, or responds to `#to_str` method. - * @exception rb_eTypeError Can't convert `str` into ::rb_cString. + * @pre `rb_type(str)` must be `T_STRING`. + * @exception rb_eEncodingError `str` contains invalid character(s). * @exception rb_eRuntimeError Too many symbols. * @return A (possibly new) id whose value is the given str. * @note These days Ruby internally has two kinds of symbols @@ -121,10 +120,17 @@ ID rb_intern_str(VALUE str); * Retrieves the name mapped to the given id. * * @param[in] id An id to query. - * @retval NULL No such id ever existed in the history. + * @retval NULL Unknown id. * @retval otherwise A name that the id represents. * @note The return value is managed by the interpreter. Don't pass it * to free(). + * @note The underlying name can contain internal NUL bytes, so the return + * value might be a truncated representation due to the nature of C + * strings. + * @note This C string is backed by an underlying Ruby string. The Ruby + * string may move during GC compaction which would make this + * C string point to invalid memory. Do not use the return value + * of this function after a potential GC entry point. */ const char *rb_id2name(ID id); @@ -159,34 +165,40 @@ RBIMPL_ATTR_NONNULL(()) * of ::rb_cSymbol, or an instance of ::rb_cString, or responds * to `#to_str` method. * @exception rb_eTypeError Can't convert `*namep` into ::rb_cString. - * @exception rb_eEncodingError Given string is non-ASCII. + * @exception rb_eEncodingError Given string contains invalid character(s). * @retval 0 No such id ever existed in the history. * @retval otherwise The id that represents the given name. * @post The object that `*namep` points to is a converted result * object, which is always an instance of either ::rb_cSymbol * or ::rb_cString. + * @see rb_str_to_str * @see https://bugs.ruby-lang.org/issues/5072 - * - * @internal - * - * @shyouhei doesn't know why this has to raise rb_eEncodingError. */ ID rb_check_id(volatile VALUE *namep); /** - * @copydoc rb_intern_str() - * - * @internal + * Identical to rb_intern_str(), except it tries to convert the parameter object + * to an instance of ::rb_cString or its subclasses. * - * :FIXME: Can anyone tell us what is the difference between this one and - * rb_intern_str()? As far as @shyouhei reads the implementation it seems what - * rb_to_id() does is is just waste some CPU time, then call rb_intern_str(). - * He hopes he is wrong. + * @param[in] str The name of the id. + * @pre `str` must either be an instance of ::rb_cSymbol, or an instance + * of ::rb_cString, or responds to `#to_str` method. + * @exception rb_eTypeError Can't convert `str` into ::rb_cString. + * @exception rb_eEncodingError Given string contains invalid character(s). + * @exception rb_eRuntimeError Too many symbols. + * @return A (possibly new) id whose value is the given str. + * @note These days Ruby internally has two kinds of symbols + * (static/dynamic). Symbols created using this function would + * become static ones; i.e. would never be garbage collected. It + * is up to you to avoid memory leaks. Think twice before using + * it. + * @see rb_str_to_str */ ID rb_to_id(VALUE str); /** - * Identical to rb_id2name(), except it returns a Ruby's String instead of C's. + * Identical to rb_id2name(), except it returns a frozen Ruby String instead of + * a C String. * * @param[in] id An id to query. * @retval RUBY_Qfalse No such id ever existed in the history. @@ -201,14 +213,14 @@ ID rb_to_id(VALUE str); VALUE rb_id2str(ID id); /** - * Identical to rb_id2str(), except it takes an instance of ::rb_cSymbol rather - * than an ::ID. + * Obtain a frozen string representation of a symbol (not including the leading + * colon). Done without any object allocations. * - * @param[in] id An id to query. - * @retval RUBY_Qfalse No such id ever existed in the history. - * @retval otherwise An instance of ::rb_cString with the name of id. + * @param[in] symbol A ::rb_cSymbol instance to query. + * @return A frozen instance of ::rb_cString with the name of `symbol`. + * @note This does not create a permanent ::ID using the symbol. */ -VALUE rb_sym2str(VALUE id); +VALUE rb_sym2str(VALUE symbol); /** * Identical to rb_intern_str(), except it generates a dynamic symbol if @@ -237,17 +249,14 @@ RBIMPL_ATTR_NONNULL(()) * of ::rb_cSymbol, or an instance of ::rb_cString, or responds * to `#to_str` method. * @exception rb_eTypeError Can't convert `*namep` into ::rb_cString. - * @exception rb_eEncodingError Given string is non-ASCII. + * @exception rb_eEncodingError Given string contains invalid character(s). * @retval RUBY_Qnil No such id ever existed in the history. * @retval otherwise The id that represents the given name. * @post The object that `*namep` points to is a converted result * object, which is always an instance of either ::rb_cSymbol * or ::rb_cString. * @see https://bugs.ruby-lang.org/issues/5072 - * - * @internal - * - * @shyouhei doesn't know why this has to raise rb_eEncodingError. + * @see rb_str_to_str */ VALUE rb_check_symbol(volatile VALUE *namep); RBIMPL_SYMBOL_EXPORT_END() @@ -308,8 +317,9 @@ rbimpl_intern_const(ID *ptr, const char *str) } /** - * Old implementation detail of rb_intern(). - * @deprecated Does anyone use it? Preserved for backward compat. + * Returns the cached ID for the given str in var, in compiler + * independent manner. Use this instead of GCC specific rb_intern() + * when you want to cache the ID on all platforms certainly. */ #define RUBY_CONST_ID(var, str) \ do { \ @@ -318,7 +328,8 @@ rbimpl_intern_const(ID *ptr, const char *str) } while (0) #if defined(HAVE_STMT_AND_DECL_IN_EXPR) -/* __builtin_constant_p and statement expression is available +/* GCC specific shorthand for RUBY_CONST_ID(). + * __builtin_constant_p and statement expression is available * since gcc-2.7.2.3 at least. */ #define rb_intern(str) \ (RBIMPL_CONSTANT_P(str) ? \ |