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      1 //===--- StmtCXX.h - Classes for representing C++ statements ----*- C++ -*-===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This file defines the C++ statement AST node classes.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #ifndef LLVM_CLANG_AST_STMTCXX_H
     15 #define LLVM_CLANG_AST_STMTCXX_H
     16 
     17 #include "clang/AST/DeclarationName.h"
     18 #include "clang/AST/Expr.h"
     19 #include "clang/AST/NestedNameSpecifier.h"
     20 #include "clang/AST/Stmt.h"
     21 #include "llvm/Support/Compiler.h"
     22 
     23 namespace clang {
     24 
     25 class VarDecl;
     26 
     27 /// CXXCatchStmt - This represents a C++ catch block.
     28 ///
     29 class CXXCatchStmt : public Stmt {
     30   SourceLocation CatchLoc;
     31   /// The exception-declaration of the type.
     32   VarDecl *ExceptionDecl;
     33   /// The handler block.
     34   Stmt *HandlerBlock;
     35 
     36 public:
     37   CXXCatchStmt(SourceLocation catchLoc, VarDecl *exDecl, Stmt *handlerBlock)
     38   : Stmt(CXXCatchStmtClass), CatchLoc(catchLoc), ExceptionDecl(exDecl),
     39     HandlerBlock(handlerBlock) {}
     40 
     41   CXXCatchStmt(EmptyShell Empty)
     42   : Stmt(CXXCatchStmtClass), ExceptionDecl(nullptr), HandlerBlock(nullptr) {}
     43 
     44   SourceLocation getLocStart() const LLVM_READONLY { return CatchLoc; }
     45   SourceLocation getLocEnd() const LLVM_READONLY {
     46     return HandlerBlock->getLocEnd();
     47   }
     48 
     49   SourceLocation getCatchLoc() const { return CatchLoc; }
     50   VarDecl *getExceptionDecl() const { return ExceptionDecl; }
     51   QualType getCaughtType() const;
     52   Stmt *getHandlerBlock() const { return HandlerBlock; }
     53 
     54   static bool classof(const Stmt *T) {
     55     return T->getStmtClass() == CXXCatchStmtClass;
     56   }
     57 
     58   child_range children() { return child_range(&HandlerBlock, &HandlerBlock+1); }
     59 
     60   friend class ASTStmtReader;
     61 };
     62 
     63 /// CXXTryStmt - A C++ try block, including all handlers.
     64 ///
     65 class CXXTryStmt : public Stmt {
     66   SourceLocation TryLoc;
     67   unsigned NumHandlers;
     68 
     69   CXXTryStmt(SourceLocation tryLoc, Stmt *tryBlock, ArrayRef<Stmt*> handlers);
     70 
     71   CXXTryStmt(EmptyShell Empty, unsigned numHandlers)
     72     : Stmt(CXXTryStmtClass), NumHandlers(numHandlers) { }
     73 
     74   Stmt const * const *getStmts() const {
     75     return reinterpret_cast<Stmt const * const*>(this + 1);
     76   }
     77   Stmt **getStmts() {
     78     return reinterpret_cast<Stmt **>(this + 1);
     79   }
     80 
     81 public:
     82   static CXXTryStmt *Create(const ASTContext &C, SourceLocation tryLoc,
     83                             Stmt *tryBlock, ArrayRef<Stmt*> handlers);
     84 
     85   static CXXTryStmt *Create(const ASTContext &C, EmptyShell Empty,
     86                             unsigned numHandlers);
     87 
     88   SourceLocation getLocStart() const LLVM_READONLY { return getTryLoc(); }
     89   SourceLocation getLocEnd() const LLVM_READONLY { return getEndLoc(); }
     90 
     91   SourceLocation getTryLoc() const { return TryLoc; }
     92   SourceLocation getEndLoc() const {
     93     return getStmts()[NumHandlers]->getLocEnd();
     94   }
     95 
     96   CompoundStmt *getTryBlock() {
     97     return cast<CompoundStmt>(getStmts()[0]);
     98   }
     99   const CompoundStmt *getTryBlock() const {
    100     return cast<CompoundStmt>(getStmts()[0]);
    101   }
    102 
    103   unsigned getNumHandlers() const { return NumHandlers; }
    104   CXXCatchStmt *getHandler(unsigned i) {
    105     return cast<CXXCatchStmt>(getStmts()[i + 1]);
    106   }
    107   const CXXCatchStmt *getHandler(unsigned i) const {
    108     return cast<CXXCatchStmt>(getStmts()[i + 1]);
    109   }
    110 
    111   static bool classof(const Stmt *T) {
    112     return T->getStmtClass() == CXXTryStmtClass;
    113   }
    114 
    115   child_range children() {
    116     return child_range(getStmts(), getStmts() + getNumHandlers() + 1);
    117   }
    118 
    119   friend class ASTStmtReader;
    120 };
    121 
    122 /// CXXForRangeStmt - This represents C++0x [stmt.ranged]'s ranged for
    123 /// statement, represented as 'for (range-declarator : range-expression)'.
    124 ///
    125 /// This is stored in a partially-desugared form to allow full semantic
    126 /// analysis of the constituent components. The original syntactic components
    127 /// can be extracted using getLoopVariable and getRangeInit.
    128 class CXXForRangeStmt : public Stmt {
    129   SourceLocation ForLoc;
    130   enum { RANGE, BEGINEND, COND, INC, LOOPVAR, BODY, END };
    131   // SubExprs[RANGE] is an expression or declstmt.
    132   // SubExprs[COND] and SubExprs[INC] are expressions.
    133   Stmt *SubExprs[END];
    134   SourceLocation ColonLoc;
    135   SourceLocation RParenLoc;
    136 public:
    137   CXXForRangeStmt(DeclStmt *Range, DeclStmt *BeginEnd,
    138                   Expr *Cond, Expr *Inc, DeclStmt *LoopVar, Stmt *Body,
    139                   SourceLocation FL, SourceLocation CL, SourceLocation RPL);
    140   CXXForRangeStmt(EmptyShell Empty) : Stmt(CXXForRangeStmtClass, Empty) { }
    141 
    142 
    143   VarDecl *getLoopVariable();
    144   Expr *getRangeInit();
    145 
    146   const VarDecl *getLoopVariable() const;
    147   const Expr *getRangeInit() const;
    148 
    149 
    150   DeclStmt *getRangeStmt() { return cast<DeclStmt>(SubExprs[RANGE]); }
    151   DeclStmt *getBeginEndStmt() {
    152     return cast_or_null<DeclStmt>(SubExprs[BEGINEND]);
    153   }
    154   Expr *getCond() { return cast_or_null<Expr>(SubExprs[COND]); }
    155   Expr *getInc() { return cast_or_null<Expr>(SubExprs[INC]); }
    156   DeclStmt *getLoopVarStmt() { return cast<DeclStmt>(SubExprs[LOOPVAR]); }
    157   Stmt *getBody() { return SubExprs[BODY]; }
    158 
    159   const DeclStmt *getRangeStmt() const {
    160     return cast<DeclStmt>(SubExprs[RANGE]);
    161   }
    162   const DeclStmt *getBeginEndStmt() const {
    163     return cast_or_null<DeclStmt>(SubExprs[BEGINEND]);
    164   }
    165   const Expr *getCond() const {
    166     return cast_or_null<Expr>(SubExprs[COND]);
    167   }
    168   const Expr *getInc() const {
    169     return cast_or_null<Expr>(SubExprs[INC]);
    170   }
    171   const DeclStmt *getLoopVarStmt() const {
    172     return cast<DeclStmt>(SubExprs[LOOPVAR]);
    173   }
    174   const Stmt *getBody() const { return SubExprs[BODY]; }
    175 
    176   void setRangeInit(Expr *E) { SubExprs[RANGE] = reinterpret_cast<Stmt*>(E); }
    177   void setRangeStmt(Stmt *S) { SubExprs[RANGE] = S; }
    178   void setBeginEndStmt(Stmt *S) { SubExprs[BEGINEND] = S; }
    179   void setCond(Expr *E) { SubExprs[COND] = reinterpret_cast<Stmt*>(E); }
    180   void setInc(Expr *E) { SubExprs[INC] = reinterpret_cast<Stmt*>(E); }
    181   void setLoopVarStmt(Stmt *S) { SubExprs[LOOPVAR] = S; }
    182   void setBody(Stmt *S) { SubExprs[BODY] = S; }
    183 
    184 
    185   SourceLocation getForLoc() const { return ForLoc; }
    186   void setForLoc(SourceLocation Loc) { ForLoc = Loc; }
    187   SourceLocation getColonLoc() const { return ColonLoc; }
    188   void setColonLoc(SourceLocation Loc) { ColonLoc = Loc; }
    189   SourceLocation getRParenLoc() const { return RParenLoc; }
    190   void setRParenLoc(SourceLocation Loc) { RParenLoc = Loc; }
    191 
    192   SourceLocation getLocStart() const LLVM_READONLY { return ForLoc; }
    193   SourceLocation getLocEnd() const LLVM_READONLY {
    194     return SubExprs[BODY]->getLocEnd();
    195   }
    196 
    197   static bool classof(const Stmt *T) {
    198     return T->getStmtClass() == CXXForRangeStmtClass;
    199   }
    200 
    201   // Iterators
    202   child_range children() {
    203     return child_range(&SubExprs[0], &SubExprs[END]);
    204   }
    205 };
    206 
    207 /// \brief Representation of a Microsoft __if_exists or __if_not_exists
    208 /// statement with a dependent name.
    209 ///
    210 /// The __if_exists statement can be used to include a sequence of statements
    211 /// in the program only when a particular dependent name does not exist. For
    212 /// example:
    213 ///
    214 /// \code
    215 /// template<typename T>
    216 /// void call_foo(T &t) {
    217 ///   __if_exists (T::foo) {
    218 ///     t.foo(); // okay: only called when T::foo exists.
    219 ///   }
    220 /// }
    221 /// \endcode
    222 ///
    223 /// Similarly, the __if_not_exists statement can be used to include the
    224 /// statements when a particular name does not exist.
    225 ///
    226 /// Note that this statement only captures __if_exists and __if_not_exists
    227 /// statements whose name is dependent. All non-dependent cases are handled
    228 /// directly in the parser, so that they don't introduce a new scope. Clang
    229 /// introduces scopes in the dependent case to keep names inside the compound
    230 /// statement from leaking out into the surround statements, which would
    231 /// compromise the template instantiation model. This behavior differs from
    232 /// Visual C++ (which never introduces a scope), but is a fairly reasonable
    233 /// approximation of the VC++ behavior.
    234 class MSDependentExistsStmt : public Stmt {
    235   SourceLocation KeywordLoc;
    236   bool IsIfExists;
    237   NestedNameSpecifierLoc QualifierLoc;
    238   DeclarationNameInfo NameInfo;
    239   Stmt *SubStmt;
    240 
    241   friend class ASTReader;
    242   friend class ASTStmtReader;
    243 
    244 public:
    245   MSDependentExistsStmt(SourceLocation KeywordLoc, bool IsIfExists,
    246                         NestedNameSpecifierLoc QualifierLoc,
    247                         DeclarationNameInfo NameInfo,
    248                         CompoundStmt *SubStmt)
    249   : Stmt(MSDependentExistsStmtClass),
    250     KeywordLoc(KeywordLoc), IsIfExists(IsIfExists),
    251     QualifierLoc(QualifierLoc), NameInfo(NameInfo),
    252     SubStmt(reinterpret_cast<Stmt *>(SubStmt)) { }
    253 
    254   /// \brief Retrieve the location of the __if_exists or __if_not_exists
    255   /// keyword.
    256   SourceLocation getKeywordLoc() const { return KeywordLoc; }
    257 
    258   /// \brief Determine whether this is an __if_exists statement.
    259   bool isIfExists() const { return IsIfExists; }
    260 
    261   /// \brief Determine whether this is an __if_exists statement.
    262   bool isIfNotExists() const { return !IsIfExists; }
    263 
    264   /// \brief Retrieve the nested-name-specifier that qualifies this name, if
    265   /// any.
    266   NestedNameSpecifierLoc getQualifierLoc() const { return QualifierLoc; }
    267 
    268   /// \brief Retrieve the name of the entity we're testing for, along with
    269   /// location information
    270   DeclarationNameInfo getNameInfo() const { return NameInfo; }
    271 
    272   /// \brief Retrieve the compound statement that will be included in the
    273   /// program only if the existence of the symbol matches the initial keyword.
    274   CompoundStmt *getSubStmt() const {
    275     return reinterpret_cast<CompoundStmt *>(SubStmt);
    276   }
    277 
    278   SourceLocation getLocStart() const LLVM_READONLY { return KeywordLoc; }
    279   SourceLocation getLocEnd() const LLVM_READONLY { return SubStmt->getLocEnd();}
    280 
    281   child_range children() {
    282     return child_range(&SubStmt, &SubStmt+1);
    283   }
    284 
    285   static bool classof(const Stmt *T) {
    286     return T->getStmtClass() == MSDependentExistsStmtClass;
    287   }
    288 };
    289 
    290 }  // end namespace clang
    291 
    292 #endif
    293