rstring.h

Go to the documentation of this file.

#ifndef RBIMPL_RSTRING_H                             /*-*-C++-*-vi:se ft=cpp:*/
#define RBIMPL_RSTRING_H
#include "ruby/internal/config.h"
#include "ruby/internal/arithmetic/long.h"
#include "ruby/internal/attr/artificial.h"
#include "ruby/internal/attr/pure.h"
#include "ruby/internal/cast.h"
#include "ruby/internal/core/rbasic.h"
#include "ruby/internal/dllexport.h"
#include "ruby/internal/fl_type.h"
#include "ruby/internal/value_type.h"
#include "ruby/internal/warning_push.h"
#include "ruby/assert.h"
 
#define RSTRING(obj)            RBIMPL_CAST((struct RString *)(obj))
 
#define RSTRING_NOEMBED         RSTRING_NOEMBED
#define RSTRING_FSTR            RSTRING_FSTR
#define RSTRING_LEN       RSTRING_LEN
#define RSTRING_LENINT    RSTRING_LENINT
#define RSTRING_PTR       RSTRING_PTR
#define RSTRING_END       RSTRING_END
#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,
 
    /* Actually,  string  encodings are  also  encoded  into the  flags,  using
     * remaining bits.*/
 
    RSTRING_FSTR            = RUBY_FL_USER17
};
 
struct RString {
 
    struct RBasic basic;
 
    long len;
 
    union {
 
        struct {
            char *ptr;
 
            union {
 
                long capa;
 
                VALUE shared;
            } aux;
        } heap;
 
        struct {
            /* This is a length 1 array because:
             *   1. GCC has a bug that does not optimize C flexible array members
             *      (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102452)
             *   2. Zero length arrays are not supported by all compilers
             */
            char ary[1];
        } embed;
    } as;
};
 
RBIMPL_SYMBOL_EXPORT_BEGIN()
VALUE rb_str_to_str(VALUE obj);
 
VALUE rb_string_value(volatile VALUE *ptr);
 
char *rb_string_value_ptr(volatile VALUE *ptr);
 
char *rb_string_value_cstr(volatile VALUE *ptr);
 
VALUE rb_str_export(VALUE obj);
 
VALUE rb_str_export_locale(VALUE obj);
 
RBIMPL_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(RBIMPL_CAST((VALUE)(v)))
 
void rb_debug_rstring_null_ptr(const char *func);
RBIMPL_SYMBOL_EXPORT_END()
 
RBIMPL_ATTR_PURE_UNLESS_DEBUG()
RBIMPL_ATTR_ARTIFICIAL()
static inline long
RSTRING_LEN(VALUE str)
{
    return RSTRING(str)->len;
}
 
RBIMPL_WARNING_PUSH()
#if RBIMPL_COMPILER_IS(Intel)
RBIMPL_WARNING_IGNORED(413)
#endif
 
RBIMPL_ATTR_PURE_UNLESS_DEBUG()
RBIMPL_ATTR_ARTIFICIAL()
static inline struct RString
rbimpl_rstring_getmem(VALUE str)
{
    RBIMPL_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.len = RSTRING_LEN(str);
        retval.as.heap.ptr = RSTRING(str)->as.embed.ary;
        return retval;
    }
}
 
RBIMPL_WARNING_POP()
 
RBIMPL_ATTR_ARTIFICIAL()
static inline char *
RSTRING_PTR(VALUE str)
{
    char *ptr = rbimpl_rstring_getmem(str).as.heap.ptr;
 
    if (RUBY_DEBUG && RB_UNLIKELY(! ptr)) {
        /* :BEWARE: @shyouhei thinks  that currently, there are  rooms for this
         * function to return  NULL.  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. */
        rb_debug_rstring_null_ptr("RSTRING_PTR");
    }
 
    return ptr;
}
 
RBIMPL_ATTR_ARTIFICIAL()
static inline char *
RSTRING_END(VALUE str)
{
    struct RString buf = rbimpl_rstring_getmem(str);
 
    if (RUBY_DEBUG && RB_UNLIKELY(! buf.as.heap.ptr)) {
        /* Ditto. */
        rb_debug_rstring_null_ptr("RSTRING_END");
    }
 
    return &buf.as.heap.ptr[buf.len];
}
 
RBIMPL_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 rbimpl_str = rbimpl_rstring_getmem(str); \
        (ptrvar) = rbimpl_str.as.heap.ptr; \
        (lenvar) = rbimpl_str.len; \
    })
#else
# define RSTRING_GETMEM(str, ptrvar, lenvar) \
    ((ptrvar) = RSTRING_PTR(str),           \
     (lenvar) = RSTRING_LEN(str))
#endif /* HAVE_STMT_AND_DECL_IN_EXPR */
#endif /* RBIMPL_RSTRING_H */