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Scopes

The root of the entire intermediate representation is the variable global_namespace. This is the namespace specified with :: in C++ source code. All other namespaces, types, variables, functions, and so forth can be found starting with this namespace.

Korean Translation
Àüü Áß°£Ç¥ÇöÀÇ ±Ù¿øÀº º¯¼ö global_namespaceÀÌ´Ù. ÀÌ°ÍÀº C++ ¼Ò½ºÄڵ忡¼­ ::°ú ÇÔ²² ³ªÅ¸³»¾îÁö´Â ³×ÀÓ½ºÆäÀ̽º´Ù. ¸ðµç ´Ù¸¥ ³×ÀÓ½ºÆäÀ̽ºµ,ŸÀÔ,º¯¼ö,ÇÔ¼öµîÀº ÀÌ ³×ÀÓ½ºÆäÀ̽º¿Í °°ÀÌ ½ÃÀ۵Ǵ °ÍÀ» ¾Ë ¼ö ÀÖ´Ù.

Besides namespaces, the other high-level scoping construct in C++ is the class. (Throughout this manual the term class is used to mean the types referred to in the ANSI/ISO C++ Standard as classes; these include types defined with the class, struct, and union keywords.) Korean Translation
³×ÀÓ½ºÆäÀ̽º¿Ü¿¡ C++¿¡¼­ ´Ù¸¥ °í±Þ·¹º§ÀÇ scopingÀ¸·Î´Â Ŭ·¡½º°¡ ÀÖ´Ù. ¸ðµç ´Ù¸¥ ³×ÀÓ½ºÆäÀ̽ºµé,ŸÀÔ(Çü,º¯¼ö,ÇÔ¼öµîÀº

Namespaces

A namespace is represented by a NAMESPACE_DECL node. Korean Translation
³×ÀÓ½ºÆäÀ̽º´Â NAMESPACE_DECL³ëµå¿¡ ÀÇÇØ Ç¥ÇöµÈ´Ù.

However, except for the fact that it is distinguished as the root of the representation, the global namespace is no different from any other namespace. Thus, in what follows, we describe namespaces generally, rather than the global namespace in particular. Korean Translation
±×·¯³ª, Ç¥ÇöÀÇ ±Ù¿øÀ¸·Î¼­ ±¸ºÐµÇ´Â »ç½Ç¿Ü¿£ global namespace´Â ´Ù¸¥ ¾î¶² ³×ÀÓ½ºÆäÀ̽º¿Í º°¹Ý Â÷ÀÌ°¡ ¾ø´Ù. ±×·¯¹Ç·Î Ưº°È÷ global_namespaceº¸´Ù´Â ÀϹÝÀûÀ¸·Î ³×ÀÓ½ºÆäÀ̽º¸¦ ¼³¸íÇÑ´Ù.

The ::std namespace, however, is special, unless flag_honor_std is set. This variable is set by the use `-fhonor-std' (or an option that implies it, like `-fnew-abi'), when invoking G++. When flag_honor_std is set, the std namespace is just like any other namespace. When flag_honor_std is not set, however, the ::std namespace is treated as a synonym for the global namespace, thereby allowing users to write code that will work with compilers that put the standard library in the ::std namespace, even though the library supplied with G++ does not do so, as of GCC 2.95. The std namespace is represented by the variable std_node. Although std_node is a NAMESPACE_DECL, it does not have all the fields required of a real namespace, and the macros and functions described here do not work, in general. It is safest simply to ignore std_node should you encounter it while examining the internal representation. In particular, you will encounter std_node while looking at the members of the global namespace. Just skip it without attempting to examine its members. Korean Translation
::std ³×ÀÓ½ºÆäÀ̽º´Â '-fhonor-sed'°¡ ¼¼ÆõÇÁö ¾Ê¾Ò´Ù¸é Ưº°ÇÑ ³×ÀÓ½ºÆäÀ̽º´Ù. ÀÌ º¯¼ö´Â G++¿¡¼­ '-flag_honor-std'¸¦ ÀÌ¿ëÇÏ¿© ¼¼ÆõȴÙ. 'flag-honor'°¡ ¼ÂµÇ¾úÀ»¶§ ::std ³×ÀÓ½ºÆäÀ̽º´Â ´Ù¸¥ ÀÏ¹Ý ³×ÀÓ½ºÆäÀ̽º¿Í °°´Ù. ¼¼ÆõÇÁö ¾Ê¾ÒÀ» °æ¿ì ::std³×ÀÓ½ºÆäÀ̽º´Â global_namespace¿¡ ´ëÇÑ µ¿ÀǾî·Î¼­ 󸮵ȴÙ. ±×¸®ÇÏ¿© »ç¿ëÀÚ°¡ ÄÄÆÄÀÏ·¯¿Í ÀÛ¾÷ÇÒ ¼ö ÀÖ´Â ÄÚµåÀÛ¼ºÀ» Çã¿ëÇϱâ À§ÇØ ::std ³×ÀÓ½ºÆäÀ̽º¿¡ standard library¸¦ ³Ö´Â´Ù(½ÉÁö¾î G++¿¡¼­ Á¦°øµÇ´Â ¶óÀ̺귯¸®°¡ ±×·¸°Ô µ¿ÀÛÇÏÁö¾Ê´õ¶óµµ). std ³×ÀÓ½ºÆäÀ̽º´Â º¯¼ö std_node¿¡ ÀÇÇØ Ç¥ÇöµÈ´Ù. ºñ·Ï std_node°¡ ÇϳªÀÇ NAMESPACE_DECLÀÌÁö¸¸ ±×°ÍÀº ½ÇÁ¦ ³×ÀÓ½ºÆäÀ̽º¿¡°Ô ÇÊ¿äÇÑ ÇʵåµéÀ» °¡Áö°í ÀÖÁö ¾Ê°í ¿©±â¼­ ¾ð±ÞµÈ ÇÔ¼ö³ª ¸ÅÅ©·ÎµéÀº ÀϹÝÀûÀ¸·Î »ç¿ëµÇÁö ¾Ê´Â´Ù. ³»ºÎÇ¥ÇöÀ» Á¶»çÇÒ ¶§ std_node¸¦ Á¢ÇÏ°Ô µÇ¸é °£´ÜÈ÷ ¹«½ÃÇÏ´Â °ÍÀÌ °¡Àå ¾ÈÀüÇÒ °ÍÀÌ´Ù. Ưº°È÷ global_namespaceÀÇ ¸â¹öµéÀ» Á¶»çÇϸ鼭 std_node¸¦ ¸¸³¯ ¼ö ÀÖÀ» °ÍÀÌ´Ù. ±×·² °æ¿ì ±×°ÍÀÇ ¸â¹öµéÀ» Á¶»çÇϱ⸦ ½ÃµµÇÏÁö¸»°í ±×³É Áö³ªÃÄ ¹ö¸°´Ù.½

The following macros and functions can be used on a NAMESPACE_DECL: ÀÌ ¸ÅÅ©·Î¿Í ÇÔ¼öµéÀº NAMESPACE_DECL¿¡¼­ »ç¿ëµÉ ¼ö ÀÖ´Ù.

DECL_NAME
This macro is used to obtain the IDENTIFIER_NODE corresponding to the unqualified name of the name of the namespace (see section Identifiers). The name of the global namespace is `::', even though in C++ the global namespace is unnamed. However, you should use comparison with global_namespace, rather than DECL_NAME to determine whether or not a namespaces is the global one. An unnamed namespace will have a DECL_NAME equal to anonymous_namespace_name. Within a single translation unit, all unnamed namespaces will have the same name. ÀÌ ¸ÅÅ©·Î´Â ³×ÀÓ½ºÆäÀ̽ºÀÇ À̸§À¸·Î¼­ ºÎÀûÀýÇÑ À̸§¿¡ »óÀÀÇÏ´Â IDENTIFIER_NODE¸¦ ¾ò´Âµ¥ »ç¿ëµÈ´Ù. ºñ·Ï C++¿¡¼± Àü¿ª ³×ÀÓ½ºÆäÀ̽º¶õ À̸§ÀÌ ¾øÁö¸¸ ¿©±â¼­ Àü¿ª ³×ÀÓ½ºÆäÀ̽º´Â '::'ÀÌ´Ù. ³×ÀÓ½ºÆäÀ̽º°¡ Àü¿ªÀÎÁöÀÇ ¿©ºÎ¸¦ °áÁ¤Çϱâ À§Çؼ± DECL_NAMEº¸´Ù´Â global_namespace¿Í ºñ±³Çؾ߸¸ ÇÑ´Ù. À̸§¾ø´Â ³×ÀÓ½ºÆäÀ̽º´Â anonymous_namespace_name¿Í °°Àº DECL_NAME¸¦ °¡Áú °ÍÀÌ´Ù. ´ÜÀÏ Çؼ®´ÜÀ§¿¡¼­ ¸ðµç À̸§¾ø´Â ³×ÀÓ½ºÆäÀ̽ºµéÀº °°Àº À̸§À» °¡Áú °ÍÀÌ´Ù.
DECL_CONTEXT
This macro returns the enclosing namespace. The DECL_CONTEXT for the global_namespace is NULL_TREE. ÀÌ ¸ÅÅ©·Î´Â enclosing(?) ³×ÀÓ½ºÆäÀ̽º¸¦ ¸®ÅÏÇÑ´Ù.
DECL_NAMESPACE_ALIAS
If this declaration is for a namespace alias, then DECL_NAMESPACE_ALIAS is the namespace for which this one is an alias. Do not attempt to use cp_namespace_decls for a namespace which is an alias. Instead, follow DECL_NAMESPACE_ALIAS links until you reach an ordinary, non-alias, namespace, and call cp_namespace_decls there. ÀÌ ¼±¾ðÀÌ ³×ÀÓ½ºÆäÀ̽º ¾Ë¸®¾î½º¿¡ ´ëÇÑ °ÍÀ̶ó¸é DECL_NAMESPACE_ALIASE´Â ±× ³×ÀÓ½ºÆäÀ̽º¿¡ ´ëÇÑ ¾Ë¸®¾î½º´Ù. ³×ÀÓ½ºÆäÀ̽ºÀÇ ¾Ë¸®¾î½º¿¡ ´ëÇØ cp_namespace_decls¸¦ »ç¿ëÇؼ­´Â ¾ÊµÈ´Ù. ´ë½Å º¸ÅÖÀÇ ¾Ë¸®¾î½º µÇÁö¾ÊÀº ³×ÀÓ½ºÆäÀ̽º¸¦ ¸¸³¯¶§±îÁö DECL_NAMESPACE_ALIAS ¸µÅ©¸¦ µû¶ó°£ ÈÄ °Å±â¼­ cp_namespace¸¦ È£ÃâÇؾßÇÑ´Ù.
DECL_NAMESPACE_STD_P
This predicate holds if the namespace is the special ::std namespace. ³×ÀÓ½ºÆäÀ̽º°¡ Ưº°ÇÑ ::stdÀÏ °æ¿ì Âü °ªÀ» °¡Áö´Â ¸ÅÅ©·Î.
cp_namespace_decls
This function will return the declarations contained in the namespace, including types, overloaded functions, other namespaces, and so forth. If there are no declarations, this function will return NULL_TREE. The declarations are connected through their TREE_CHAIN fields. Although most entries on this list will be declarations, TREE_LIST nodes may also appear. In this case, the TREE_VALUE will be an OVERLOAD. The value of the TREE_PURPOSE is unspecified; back-ends should ignore this value. As with the other kinds of declarations returned by cp_namespace_decls, the TREE_CHAIN will point to the next declaration in this list. For more information on the kinds of declarations that can occur on this list, See section Declarations. Some declarations will not appear on this list. In particular, no FIELD_DECL, LABEL_DECL, or PARM_DECL nodes will appear here. This function cannot be used with namespaces that have DECL_NAMESPACE_ALIAS set.
ÀÌ ÇÔ¼ö´Â ³×ÀÓ½ºÆäÀ̽º,Æ÷ÇÔÇϴ ŸÀÔµé,¿À¹ö·ÎµåµÈ ÇÔ¼öµé,´Ù¸¥ ³×ÀÓ½ºÆäÀ̽ºµîÀ» Æ÷ÇÔÇÏ´Â ¼±¾ðÀ» ¸®ÅÏÇÑ´Ù. °Å±â¿¡ ¾Æ¹« ¼±¾ðµµ ¾ÈµÇ¾î ÀÖ´Ù¸é ÀÌ ÇÔ¼ö´Â NULL_TREE¸¦ ¸®ÅÏÇÒ °ÍÀÌ´Ù. ±× ¼±¾ðµéÀº ±×µéÀÇ TREE_CHAIN Çʵ带 ÅëÇÏ¿© ¿¬°áµÈ´Ù. ºñ·Ï ÀÌ ¸®½ºÆ®¿¡ ´ëºÎºÐ ¿£Æ®¸®µéÀÌ ¼±¾ðºÎºÐÀÌÁö¸¸ TREE_LIST ¶ÇÇÑ ³ªÅ¸³¯ Áöµµ ¸ð¸¥´Ù. ÀÌ °æ¿ì TREE_VALUE´Â OVERLOAD°¡ µÉ °ÍÀÌ´Ù. TREE_PURPOSEÀÇ °ªÀº Á¤ÇØÁöÁö ¾Ê´Â´Ù. cp_namespace_decls¿¡ ÀÇÇØ ¸®ÅϵǴ ¼±¾ðµéÀÇ ´Ù¸¥ Á¾·ù·Î¼­ TREE_CHAINÀº ÀÌ ¸®½ºÆ®¾È¿¡¼­ ´ÙÀ½ ¼±¾ðºÎºÐÀ» °¡¸®Å³ °ÍÀÌ´Ù. ÀÌ ¸®½ºÆ®¿¡¼­ ÀϾ ¼ö ÀÖ´Â ¼±¾ðµéÀÇ ´Ù¸¥ Á¾·ùµé¿¡ ´ëÇØ ´õ ¾Ë°íÀÚ ÇÑ´Ù¸é Declarations ºÎºÐÀ» ÂüÁ¶Ç϶ó. ¾î¶² ¼±¾ðµéÀº ÀÌ ¸®½ºÆ®¿¡¼­ ³ªÅ¸³ªÁö ¾ÊÀ» °ÍÀÌ´Ù. Ưº°È÷ FIELD_DECL,LABEL_DECL,PARM_DECLµîÀº ¿©±â¼­ ³ªÅ¸³ªÁö ¾Ê´Â´Ù. ÀÌ ÇÔ¼ö´Â DECL_NAMESPACE_ALIAS°ªÀ» °¡Áö´Â ³×ÀÓ½ºÆäÀ̽ºµé°ú ÇÔ²² »ç¿ëµÇ¾î Áú ¼ö ¾ø´Ù. ÷

Classes

A class type is represented by either a RECORD_TYPE or a UNION_TYPE. A class declared with the union tag is represented by a UNION_TYPE, while classes declared with either the struct or the class tag are represented by RECORD_TYPEs. You can use the CLASSTYPE_DECLARED_CLASS macro to discern whether or not a particular type is a class as opposed to a struct. This macro will be true only for classes declared with the class tag. Ŭ·¡½º ŸÀÔÀº RECORD_TYPE ȤÀº UNION_TYPEÀ¸·Î Ç¥ÇöµÈ´Ù. union ÅÂÅ©¿Í ÇÔ²² ¼±¾ðµÈ Ŭ·¡½º´Â UNION_TYPE¿¡ ÀÇÇØ Ç¥ÇöµÈ´Ù. ¹Ý¸é¿¡ struct ¶Ç´Â class ű׷Π¼±¾ðµÈ Ŭ·¡½º´Â RECORD_TYPE¿¡ ÀÇÇØ Ç¥ÇöµÈ´Ù. ƯÁ¤ÇÑ Å¸ÀÔ¿¡ ´ëÇØ class ȤÀº ÀÌ¿Í ±¸º°µÇ´Â struct ÀÎÁö¸¦ ¾Ë±âÀ§ÇØ CLASSTYPE_DECLARED_CLASS ¸ÅÅ©·Î¸¦ »ç¿ëÇÒ ¼ö ÀÖ´Ù. ÀÌ ¸ÅÅ©·Î´Â class ÅÂÅ©·Î ¼±¾ðµÈ Ŭ·¡½ºµé¿¡ ´ëÇØ Âü°ªÀ» °¡Áø´Ù.

Almost all non-function members are available on the TYPE_FIELDS list. Given one member, the next can be found by following the TREE_CHAIN. You should not depend in any way on the order in which fields appear on this list. All nodes on this list will be `DECL' nodes. A FIELD_DECL is used to represent a non-static data member, a VAR_DECL is used to represent a static data member, and a TYPE_DECL is used to represent a type. Note that the CONST_DECL for an enumeration constant will appear on this list, if the enumeration type was declared in the class. (Of course, the TYPE_DECL for the enumeration type will appear here as well.) There are no entries for base classes on this list. In particular, there is no FIELD_DECL for the "base-class portion" of an object. °ÅÀÇ ¸ðµç ºñÇÔ¼öÇü ¸â¹öµéÀº TYPE_FIELDS ¸®½ºÆ®¸¦ ÀÌ¿ëÇÒ ¼ö ÀÖ´Ù. ÁÖ¾îÁø ÇϳªÀÇ ¸â¹ö¿¡ ´ëÇØ ´ÙÀ½ ¸â¹ö´Â TREE_CHAINÇʵ带 ÀÌ¿ëÇÏ¿© ãÀ» ¼ö ÀÖ´Ù. ¾î¶² °æ¿ì¿¡µµ ÀÌ ¸®½ºÆ®¿¡ ³ªÅ¸³­ ÇʵåµéÀÇ ¿ì¼±¼øÀ§¿¡ ÀÇÁ¸Çؼ­´Â ¾ÊµÈ´Ù. ÀÌ ¸®½ºÆ®ÀÇ ¸ðµç ³ëµåµéÀº 'DECL' ³ëµå ÀÏ°ÍÀÌ´Ù. FIELD_DECLÀº ºñÁ¤Àû µ¥ÀÌŸ ¸â¹ö¸¦ Ç¥ÇöÇϱâ À§ÇØ ±×¸®°í, VAR_DECLÀº Á¤Àû µ¥ÀÌŸ ¸â¹ö¸¦ Ç¥ÇöÇϱâ À§ÇØ »ç¿ëµÈ´Ù. ¶ÇÇÑ TYPE_DECLÀº ŸÀÔÀ» ³ªÅ¸³»±â À§ÇØ »ç¿ëµÈ´Ù.

The TYPE_VFIELD is a compiler-generated field used to point to virtual function tables. It may or may not appear on the TYPE_FIELDS list. However, back-ends should handle the TYPE_VFIELD just like all the entries on the TYPE_FIELDS list.

The function members are available on the TYPE_METHODS list. Again, subsequent members are found by following the TREE_CHAIN field. If a function is overloaded, each of the overloaded functions appears; no OVERLOAD nodes appear on the TYPE_METHODS list. Implicitly declared functions (including default constructors, copy constructors, assignment operators, and destructors) will appear on this list as well.

Every class has an associated binfo, which can be obtained with TYPE_BINFO. Binfos are used to represent base-classes. The binfo given by TYPE_BINFO is the degenerate case, whereby every class is considered to be its own base-class. The base classes for a particular binfo can be obtained with BINFO_BASETYPES. These base-classes are themselves binfos. The class type associated with a binfo is given by BINFO_TYPE. It is always the case that BINFO_TYPE (TYPE_BINFO (x)) is the same type as x, up to qualifiers. However, it is not always the case that TYPE_BINFO (BINFO_TYPE (y)) is always the same binfo as y. The reason is that if y is a binfo representing a base-class B of a derived class D, then BINFO_TYPE (y) will be B, and TYPE_INFO (BINFO_TYPE (y)) will be B as its own base-class, rather than as a base-class of D.

The BINFO_BASETYPES is a TREE_VEC (see section Containers). Base types appear in left-to-right order in this vector. You can tell whether or public, protected, or private inheritance was used by using the TREE_VIA_PUBLIC, TREE_VIA_PROTECTED, and TREE_VIA_PRIVATE macros. Each of these macros takes a BINFO and is true if and only if the indicated kind of inheritance was used. If TREE_VIA_VIRTUAL holds of a binfo, then its BINFO_TYPE was inherited from virtually.

FIXME: Talk about TYPE_NONCOPIED_PARTS.

The following macros can be used on a tree node representing a class-type.

LOCAL_CLASS_P
This predicate holds if the class is local class i.e. declared inside a function body.
TYPE_POLYMORPHIC_P
This predicate holds if the class has at least one virtual function (declared or inherited).
TYPE_HAS_DEFAULT_CONSTRUCTOR
This predicate holds whenever its argument represents a class-type with default constructor.
CLASSTYPE_HAS_MUTABLE
TYPE_HAS_MUTABLE_P
These predicates hold for a class-type having a mutable data member.
CLASSTYPE_NON_POD_P
This predicate holds only for class-types that are not PODs.
TYPE_HAS_NEW_OPERATOR
This predicate holds for a class-type that defines operator new.
TYPE_HAS_ARRAY_NEW_OPERATOR
This predicate holds for a class-type for which operator new[] is defined.
TYPE_OVERLOADS_CALL_EXPR
This predicate holds for class-type for which the function call operator() is overloaded.
TYPE_OVERLOADS_ARRAY_REF
This predicate holds for a class-type that overloads operator[]
TYPE_OVERLOADS_ARROW
This predicate holds for a class-type for which operator-> is overloaded.


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