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Diffstat (limited to 'include/ruby/3/core/rstring.h')
| -rw-r--r-- | include/ruby/3/core/rstring.h | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/include/ruby/3/core/rstring.h b/include/ruby/3/core/rstring.h new file mode 100644 index 0000000000..266edca9b6 --- /dev/null +++ b/include/ruby/3/core/rstring.h @@ -0,0 +1,207 @@ +/** \noop-*-C++-*-vi:ft=cpp + * @file + * @author Ruby developers <ruby-core@ruby-lang.org> + * @copyright This file is a part of the programming language Ruby. + * Permission is hereby granted, to either redistribute and/or + * modify this file, provided that the conditions mentioned in the + * file COPYING are met. Consult the file for details. + * @warning Symbols prefixed with either `RUBY3` or `ruby3` are + * implementation details. Don't take them as canon. They could + * rapidly appear then vanish. The name (path) of this header file + * is also an implementation detail. Do not expect it to persist + * at the place it is now. Developers are free to move it anywhere + * anytime at will. + * @note To ruby-core: remember that this header can be possibly + * recursively included from extension libraries written in C++. + * Do not expect for instance `__VA_ARGS__` is always available. + * We assume C99 for ruby itself but we don't assume languages of + * extension libraries. They could be written in C++98. + * @brief Defines struct ::RString. + */ +#ifndef RUBY3_RSTRING_H +#define RUBY3_RSTRING_H +#include "ruby/3/config.h" +#include "ruby/3/arithmetic/long.h" +#include "ruby/3/attr/artificial.h" +#include "ruby/3/attr/pure.h" +#include "ruby/3/cast.h" +#include "ruby/3/core/rbasic.h" +#include "ruby/3/dllexport.h" +#include "ruby/3/fl_type.h" +#include "ruby/3/value_type.h" +#include "ruby/assert.h" + +#define RSTRING(obj) RUBY3_CAST((struct RString *)(obj)) +#define RSTRING_NOEMBED RSTRING_NOEMBED +#define RSTRING_EMBED_LEN_MASK RSTRING_EMBED_LEN_MASK +#define RSTRING_EMBED_LEN_SHIFT RSTRING_EMBED_LEN_SHIFT +#define RSTRING_EMBED_LEN_MAX RSTRING_EMBED_LEN_MAX +#define RSTRING_FSTR RSTRING_FSTR + +/** @cond INTERNAL_MACRO */ +#define RSTRING_EMBED_LEN RSTRING_EMBED_LEN +#define RSTRING_LEN RSTRING_LEN +#define RSTRING_LENINT RSTRING_LENINT +#define RSTRING_PTR RSTRING_PTR +#define RSTRING_END RSTRING_END +/** @endcond */ + +#define StringValue(v) rb_string_value(&(v)) +#define StringValuePtr(v) rb_string_value_ptr(&(v)) +#define StringValueCStr(v) rb_string_value_cstr(&(v)) +#define SafeStringValue(v) StringValue(v) +#define ExportStringValue(v) do { \ + StringValue(v); \ + (v) = rb_str_export(v); \ +} while (0) + +enum ruby_rstring_flags { + RSTRING_NOEMBED = RUBY_FL_USER1, + RSTRING_EMBED_LEN_MASK = RUBY_FL_USER2 | RUBY_FL_USER3 | RUBY_FL_USER4 | + RUBY_FL_USER5 | RUBY_FL_USER6, + /* Actually, string encodings are also encoded into the flags, using + * remaining bits.*/ + RSTRING_FSTR = RUBY_FL_USER17 +}; + +enum { + RSTRING_EMBED_LEN_SHIFT = RUBY_FL_USHIFT + 2, + RSTRING_EMBED_LEN_MAX = RUBY3_EMBED_LEN_MAX_OF(char) - 1 +}; + +struct RString { + struct RBasic basic; + union { + struct { + long len; + char *ptr; + union { + long capa; + VALUE shared; + } aux; + } heap; + char ary[RSTRING_EMBED_LEN_MAX + 1]; + } as; +}; + +RUBY3_SYMBOL_EXPORT_BEGIN() +VALUE rb_str_to_str(VALUE); +VALUE rb_string_value(volatile VALUE*); +char *rb_string_value_ptr(volatile VALUE*); +char *rb_string_value_cstr(volatile VALUE*); +VALUE rb_str_export(VALUE); +VALUE rb_str_export_locale(VALUE); + +RUBY3_ATTR_ERROR(("rb_check_safe_str() and Check_SafeStr() are obsolete; use StringValue() instead")) +void rb_check_safe_str(VALUE); +#define Check_SafeStr(v) rb_check_safe_str(RUBY3_CAST((VALUE)(v))) +RUBY3_SYMBOL_EXPORT_END() + +RUBY3_ATTR_PURE_ON_NDEBUG() +RUBY3_ATTR_ARTIFICIAL() +static inline long +RSTRING_EMBED_LEN(VALUE str) +{ + RUBY3_ASSERT_TYPE(str, RUBY_T_STRING); + RUBY3_ASSERT_OR_ASSUME(! RB_FL_ANY_RAW(str, RSTRING_NOEMBED)); + + VALUE f = RBASIC(str)->flags; + f &= RSTRING_EMBED_LEN_MASK; + f >>= RSTRING_EMBED_LEN_SHIFT; + return f; +} + +RUBY3_ATTR_PURE_ON_NDEBUG() +RUBY3_ATTR_ARTIFICIAL() +static inline struct RString +ruby3_rstring_getmem(VALUE str) +{ + RUBY3_ASSERT_TYPE(str, RUBY_T_STRING); + + if (RB_FL_ANY_RAW(str, RSTRING_NOEMBED)) { + return *RSTRING(str); + } + else { + /* Expecting compilers to optimize this on-stack struct away. */ + struct RString retval; + retval.as.heap.len = RSTRING_EMBED_LEN(str); + retval.as.heap.ptr = RSTRING(str)->as.ary; + return retval; + } +} + +RUBY3_ATTR_PURE_ON_NDEBUG() +RUBY3_ATTR_ARTIFICIAL() +static inline long +RSTRING_LEN(VALUE str) +{ + return ruby3_rstring_getmem(str).as.heap.len; +} + +RUBY3_ATTR_ARTIFICIAL() +static inline char * +RSTRING_PTR(VALUE str) +{ + char *ptr = ruby3_rstring_getmem(str).as.heap.ptr; + + if (RB_UNLIKELY(! ptr)) { + /* :BEWARE: @shyouhei thinks that currently, there are rooms for this + * function to return NULL. In the 20th century that was a pointless + * concern. However struct RString can hold fake strings nowadays. It + * seems no check against NULL are exercised around handling of them + * (one of such usages is located in marshal.c, which scares + * @shyouhei). Better check here for maximum safety. + * + * Also, this is not rb_warn() because RSTRING_PTR() can be called + * during GC (see what obj_info() does). rb_warn() needs to allocate + * Ruby objects. That is not possible at this moment. */ + fprintf(stderr, "%s\n", + "RSTRING_PTR is returning NULL!! " + "SIGSEGV is highly expected to follow immediately. " + "If you could reproduce, attach your debugger here, " + "and look at the passed string." + ); + } + + return ptr; +} + +RUBY3_ATTR_ARTIFICIAL() +static inline char * +RSTRING_END(VALUE str) +{ + struct RString buf = ruby3_rstring_getmem(str); + + if (RB_UNLIKELY(! buf.as.heap.ptr)) { + /* Ditto. */ + fprintf(stderr, "%s\n", + "RSTRING_END is returning NULL!! " + "SIGSEGV is highly expected to follow immediately. " + "If you could reproduce, attach your debugger here, " + "and look at the passed string." + ); + } + + return &buf.as.heap.ptr[buf.as.heap.len]; +} + +RUBY3_ATTR_ARTIFICIAL() +static inline int +RSTRING_LENINT(VALUE str) +{ + return rb_long2int(RSTRING_LEN(str)); +} + +#ifdef HAVE_STMT_AND_DECL_IN_EXPR +# define RSTRING_GETMEM(str, ptrvar, lenvar) \ + __extension__ ({ \ + struct RString ruby3_str = ruby3_rstring_getmem(str); \ + (ptrvar) = ruby3_str.as.heap.ptr; \ + (lenvar) = ruby3_str.as.heap.len; \ + }) +#else +# define RSTRING_GETMEM(str, ptrvar, lenvar) \ + ((ptrvar) = RSTRING_PTR(str), \ + (lenvar) = RSTRING_LEN(str)) +#endif /* HAVE_STMT_AND_DECL_IN_EXPR */ +#endif /* RUBY3_RSTRING_H */ |