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//===--- Scope.h - Scope interface ------------------------------*- C++ -*-===//
// The LLVM Compiler Infrastructure
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
// This file defines the Scope interface.
#include "clang/Basic/Diagnostic.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
namespace clang {
class Decl;
class UsingDirectiveDecl;
/// Scope - A scope is a transient data structure that is used while parsing the
/// program. It assists with resolving identifiers to the appropriate
/// declaration.
class Scope {
/// ScopeFlags - These are bitfields that are or'd together when creating a
/// scope, which defines the sorts of things the scope contains.
enum ScopeFlags {
/// FnScope - This indicates that the scope corresponds to a function, which
/// means that labels are set here.
FnScope = 0x01,
/// BreakScope - This is a while,do,switch,for, etc that can have break
/// stmts embedded into it.
BreakScope = 0x02,
/// ContinueScope - This is a while,do,for, which can have continue
/// stmt embedded into it.
ContinueScope = 0x04,
/// DeclScope - This is a scope that can contain a declaration. Some scopes
/// just contain loop constructs but don't contain decls.
DeclScope = 0x08,
/// ControlScope - The controlling scope in a if/switch/while/for statement.
ControlScope = 0x10,
/// ClassScope - The scope of a struct/union/class definition.
ClassScope = 0x20,
/// BlockScope - This is a scope that corresponds to a block/closure object.
/// Blocks serve as top-level scopes for some objects like labels, they
/// also prevent things like break and continue. BlockScopes always have
/// the FnScope and DeclScope flags set as well.
BlockScope = 0x40,
/// TemplateParamScope - This is a scope that corresponds to the
/// template parameters of a C++ template. Template parameter
/// scope starts at the 'template' keyword and ends when the
/// template declaration ends.
TemplateParamScope = 0x80,
/// FunctionPrototypeScope - This is a scope that corresponds to the
/// parameters within a function prototype.
FunctionPrototypeScope = 0x100,
/// AtCatchScope - This is a scope that corresponds to the Objective-C
/// \@catch statement.
AtCatchScope = 0x200,
/// ObjCMethodScope - This scope corresponds to an Objective-C method body.
/// It always has FnScope and DeclScope set as well.
ObjCMethodScope = 0x400,
/// SwitchScope - This is a scope that corresponds to a switch statement.
SwitchScope = 0x800,
/// TryScope - This is the scope of a C++ try statement.
TryScope = 0x1000
/// The parent scope for this scope. This is null for the translation-unit
/// scope.
Scope *AnyParent;
/// Depth - This is the depth of this scope. The translation-unit scope has
/// depth 0.
unsigned short Depth;
/// Flags - This contains a set of ScopeFlags, which indicates how the scope
/// interrelates with other control flow statements.
unsigned short Flags;
/// PrototypeDepth - This is the number of function prototype scopes
/// enclosing this scope, including this scope.
unsigned short PrototypeDepth;
/// PrototypeIndex - This is the number of parameters currently
/// declared in this scope.
unsigned short PrototypeIndex;
/// FnParent - If this scope has a parent scope that is a function body, this
/// pointer is non-null and points to it. This is used for label processing.
Scope *FnParent;
/// BreakParent/ContinueParent - This is a direct link to the innermost
/// BreakScope/ContinueScope which contains the contents of this scope
/// for control flow purposes (and might be this scope itself), or null
/// if there is no such scope.
Scope *BreakParent, *ContinueParent;
/// BlockParent - This is a direct link to the immediately containing
/// BlockScope if this scope is not one, or null if there is none.
Scope *BlockParent;
/// TemplateParamParent - This is a direct link to the
/// immediately containing template parameter scope. In the
/// case of nested templates, template parameter scopes can have
/// other template parameter scopes as parents.
Scope *TemplateParamParent;
/// DeclsInScope - This keeps track of all declarations in this scope. When
/// the declaration is added to the scope, it is set as the current
/// declaration for the identifier in the IdentifierTable. When the scope is
/// popped, these declarations are removed from the IdentifierTable's notion
/// of current declaration. It is up to the current Action implementation to
/// implement these semantics.
typedef llvm::SmallPtrSet<Decl *, 32> DeclSetTy;
DeclSetTy DeclsInScope;
/// Entity - The entity with which this scope is associated. For
/// example, the entity of a class scope is the class itself, the
/// entity of a function scope is a function, etc. This field is
/// maintained by the Action implementation.
void *Entity;
typedef SmallVector<UsingDirectiveDecl *, 2> UsingDirectivesTy;
UsingDirectivesTy UsingDirectives;
/// \brief Used to determine if errors occurred in this scope.
DiagnosticErrorTrap ErrorTrap;
Scope(Scope *Parent, unsigned ScopeFlags, DiagnosticsEngine &Diag)
: ErrorTrap(Diag) {
Init(Parent, ScopeFlags);
/// getFlags - Return the flags for this scope.
unsigned getFlags() const { return Flags; }
void setFlags(unsigned F) { Flags = F; }
/// isBlockScope - Return true if this scope correspond to a closure.
bool isBlockScope() const { return Flags & BlockScope; }
/// getParent - Return the scope that this is nested in.
const Scope *getParent() const { return AnyParent; }
Scope *getParent() { return AnyParent; }
/// getFnParent - Return the closest scope that is a function body.
const Scope *getFnParent() const { return FnParent; }
Scope *getFnParent() { return FnParent; }
/// getContinueParent - Return the closest scope that a continue statement
/// would be affected by.
Scope *getContinueParent() {
return ContinueParent;
const Scope *getContinueParent() const {
return const_cast<Scope*>(this)->getContinueParent();
/// getBreakParent - Return the closest scope that a break statement
/// would be affected by.
Scope *getBreakParent() {
return BreakParent;
const Scope *getBreakParent() const {
return const_cast<Scope*>(this)->getBreakParent();
Scope *getBlockParent() { return BlockParent; }
const Scope *getBlockParent() const { return BlockParent; }
Scope *getTemplateParamParent() { return TemplateParamParent; }
const Scope *getTemplateParamParent() const { return TemplateParamParent; }
/// Returns the number of function prototype scopes in this scope
/// chain.
unsigned getFunctionPrototypeDepth() const {
return PrototypeDepth;
/// Return the number of parameters declared in this function
/// prototype, increasing it by one for the next call.
unsigned getNextFunctionPrototypeIndex() {
return PrototypeIndex++;
typedef DeclSetTy::iterator decl_iterator;
decl_iterator decl_begin() const { return DeclsInScope.begin(); }
decl_iterator decl_end() const { return DeclsInScope.end(); }
bool decl_empty() const { return DeclsInScope.empty(); }
void AddDecl(Decl *D) {
void RemoveDecl(Decl *D) {
/// isDeclScope - Return true if this is the scope that the specified decl is
/// declared in.
bool isDeclScope(Decl *D) {
return DeclsInScope.count(D) != 0;
void* getEntity() const { return Entity; }
void setEntity(void *E) { Entity = E; }
bool hasErrorOccurred() const { return ErrorTrap.hasErrorOccurred(); }
/// isClassScope - Return true if this scope is a class/struct/union scope.
bool isClassScope() const {
return (getFlags() & Scope::ClassScope);
/// isInCXXInlineMethodScope - Return true if this scope is a C++ inline
/// method scope or is inside one.
bool isInCXXInlineMethodScope() const {
if (const Scope *FnS = getFnParent()) {
assert(FnS->getParent() && "TUScope not created?");
return FnS->getParent()->isClassScope();
return false;
/// isInObjcMethodScope - Return true if this scope is, or is contained in, an
/// Objective-C method body. Note that this method is not constant time.
bool isInObjcMethodScope() const {
for (const Scope *S = this; S; S = S->getParent()) {
// If this scope is an objc method scope, then we succeed.
if (S->getFlags() & ObjCMethodScope)
return true;
return false;
/// isTemplateParamScope - Return true if this scope is a C++
/// template parameter scope.
bool isTemplateParamScope() const {
return getFlags() & Scope::TemplateParamScope;
/// isFunctionPrototypeScope - Return true if this scope is a
/// function prototype scope.
bool isFunctionPrototypeScope() const {
return getFlags() & Scope::FunctionPrototypeScope;
/// isAtCatchScope - Return true if this scope is \@catch.
bool isAtCatchScope() const {
return getFlags() & Scope::AtCatchScope;
/// isSwitchScope - Return true if this scope is a switch scope.
bool isSwitchScope() const {
for (const Scope *S = this; S; S = S->getParent()) {
if (S->getFlags() & Scope::SwitchScope)
return true;
else if (S->getFlags() & (Scope::FnScope | Scope::ClassScope |
Scope::BlockScope | Scope::TemplateParamScope |
Scope::FunctionPrototypeScope |
Scope::AtCatchScope | Scope::ObjCMethodScope))
return false;
return false;
/// \brief Determine whether this scope is a C++ 'try' block.
bool isTryScope() const { return getFlags() & Scope::TryScope; }
/// containedInPrototypeScope - Return true if this or a parent scope
/// is a FunctionPrototypeScope.
bool containedInPrototypeScope() const;
typedef UsingDirectivesTy::iterator udir_iterator;
typedef UsingDirectivesTy::const_iterator const_udir_iterator;
void PushUsingDirective(UsingDirectiveDecl *UDir) {
udir_iterator using_directives_begin() {
return UsingDirectives.begin();
udir_iterator using_directives_end() {
return UsingDirectives.end();
const_udir_iterator using_directives_begin() const {
return UsingDirectives.begin();
const_udir_iterator using_directives_end() const {
return UsingDirectives.end();
/// Init - This is used by the parser to implement scope caching.
void Init(Scope *parent, unsigned flags);
} // end namespace clang