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:
CXXCatchStmt(SourceLocation catchLoc,VarDecl * exDecl,Stmt * handlerBlock)37   CXXCatchStmt(SourceLocation catchLoc, VarDecl *exDecl, Stmt *handlerBlock)
38   : Stmt(CXXCatchStmtClass), CatchLoc(catchLoc), ExceptionDecl(exDecl),
39     HandlerBlock(handlerBlock) {}
40 
CXXCatchStmt(EmptyShell Empty)41   CXXCatchStmt(EmptyShell Empty)
42   : Stmt(CXXCatchStmtClass), ExceptionDecl(nullptr), HandlerBlock(nullptr) {}
43 
getLocStart()44   SourceLocation getLocStart() const LLVM_READONLY { return CatchLoc; }
getLocEnd()45   SourceLocation getLocEnd() const LLVM_READONLY {
46     return HandlerBlock->getLocEnd();
47   }
48 
getCatchLoc()49   SourceLocation getCatchLoc() const { return CatchLoc; }
getExceptionDecl()50   VarDecl *getExceptionDecl() const { return ExceptionDecl; }
51   QualType getCaughtType() const;
getHandlerBlock()52   Stmt *getHandlerBlock() const { return HandlerBlock; }
53 
classof(const Stmt * T)54   static bool classof(const Stmt *T) {
55     return T->getStmtClass() == CXXCatchStmtClass;
56   }
57 
children()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 
CXXTryStmt(EmptyShell Empty,unsigned numHandlers)71   CXXTryStmt(EmptyShell Empty, unsigned numHandlers)
72     : Stmt(CXXTryStmtClass), NumHandlers(numHandlers) { }
73 
getStmts()74   Stmt const * const *getStmts() const {
75     return reinterpret_cast<Stmt const * const*>(this + 1);
76   }
getStmts()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 
getLocStart()88   SourceLocation getLocStart() const LLVM_READONLY { return getTryLoc(); }
getLocEnd()89   SourceLocation getLocEnd() const LLVM_READONLY { return getEndLoc(); }
90 
getTryLoc()91   SourceLocation getTryLoc() const { return TryLoc; }
getEndLoc()92   SourceLocation getEndLoc() const {
93     return getStmts()[NumHandlers]->getLocEnd();
94   }
95 
getTryBlock()96   CompoundStmt *getTryBlock() {
97     return cast<CompoundStmt>(getStmts()[0]);
98   }
getTryBlock()99   const CompoundStmt *getTryBlock() const {
100     return cast<CompoundStmt>(getStmts()[0]);
101   }
102 
getNumHandlers()103   unsigned getNumHandlers() const { return NumHandlers; }
getHandler(unsigned i)104   CXXCatchStmt *getHandler(unsigned i) {
105     return cast<CXXCatchStmt>(getStmts()[i + 1]);
106   }
getHandler(unsigned i)107   const CXXCatchStmt *getHandler(unsigned i) const {
108     return cast<CXXCatchStmt>(getStmts()[i + 1]);
109   }
110 
classof(const Stmt * T)111   static bool classof(const Stmt *T) {
112     return T->getStmtClass() == CXXTryStmtClass;
113   }
114 
children()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 CoawaitLoc;
135   SourceLocation ColonLoc;
136   SourceLocation RParenLoc;
137 
138   friend class ASTStmtReader;
139 public:
140   CXXForRangeStmt(DeclStmt *Range, DeclStmt *BeginEnd,
141                   Expr *Cond, Expr *Inc, DeclStmt *LoopVar, Stmt *Body,
142                   SourceLocation FL, SourceLocation CAL, SourceLocation CL,
143                   SourceLocation RPL);
CXXForRangeStmt(EmptyShell Empty)144   CXXForRangeStmt(EmptyShell Empty) : Stmt(CXXForRangeStmtClass, Empty) { }
145 
146 
147   VarDecl *getLoopVariable();
148   Expr *getRangeInit();
149 
150   const VarDecl *getLoopVariable() const;
151   const Expr *getRangeInit() const;
152 
153 
getRangeStmt()154   DeclStmt *getRangeStmt() { return cast<DeclStmt>(SubExprs[RANGE]); }
getBeginEndStmt()155   DeclStmt *getBeginEndStmt() {
156     return cast_or_null<DeclStmt>(SubExprs[BEGINEND]);
157   }
getCond()158   Expr *getCond() { return cast_or_null<Expr>(SubExprs[COND]); }
getInc()159   Expr *getInc() { return cast_or_null<Expr>(SubExprs[INC]); }
getLoopVarStmt()160   DeclStmt *getLoopVarStmt() { return cast<DeclStmt>(SubExprs[LOOPVAR]); }
getBody()161   Stmt *getBody() { return SubExprs[BODY]; }
162 
getRangeStmt()163   const DeclStmt *getRangeStmt() const {
164     return cast<DeclStmt>(SubExprs[RANGE]);
165   }
getBeginEndStmt()166   const DeclStmt *getBeginEndStmt() const {
167     return cast_or_null<DeclStmt>(SubExprs[BEGINEND]);
168   }
getCond()169   const Expr *getCond() const {
170     return cast_or_null<Expr>(SubExprs[COND]);
171   }
getInc()172   const Expr *getInc() const {
173     return cast_or_null<Expr>(SubExprs[INC]);
174   }
getLoopVarStmt()175   const DeclStmt *getLoopVarStmt() const {
176     return cast<DeclStmt>(SubExprs[LOOPVAR]);
177   }
getBody()178   const Stmt *getBody() const { return SubExprs[BODY]; }
179 
setRangeInit(Expr * E)180   void setRangeInit(Expr *E) { SubExprs[RANGE] = reinterpret_cast<Stmt*>(E); }
setRangeStmt(Stmt * S)181   void setRangeStmt(Stmt *S) { SubExprs[RANGE] = S; }
setBeginEndStmt(Stmt * S)182   void setBeginEndStmt(Stmt *S) { SubExprs[BEGINEND] = S; }
setCond(Expr * E)183   void setCond(Expr *E) { SubExprs[COND] = reinterpret_cast<Stmt*>(E); }
setInc(Expr * E)184   void setInc(Expr *E) { SubExprs[INC] = reinterpret_cast<Stmt*>(E); }
setLoopVarStmt(Stmt * S)185   void setLoopVarStmt(Stmt *S) { SubExprs[LOOPVAR] = S; }
setBody(Stmt * S)186   void setBody(Stmt *S) { SubExprs[BODY] = S; }
187 
getForLoc()188   SourceLocation getForLoc() const { return ForLoc; }
getCoawaitLoc()189   SourceLocation getCoawaitLoc() const { return CoawaitLoc; }
getColonLoc()190   SourceLocation getColonLoc() const { return ColonLoc; }
getRParenLoc()191   SourceLocation getRParenLoc() const { return RParenLoc; }
192 
getLocStart()193   SourceLocation getLocStart() const LLVM_READONLY { return ForLoc; }
getLocEnd()194   SourceLocation getLocEnd() const LLVM_READONLY {
195     return SubExprs[BODY]->getLocEnd();
196   }
197 
classof(const Stmt * T)198   static bool classof(const Stmt *T) {
199     return T->getStmtClass() == CXXForRangeStmtClass;
200   }
201 
202   // Iterators
children()203   child_range children() {
204     return child_range(&SubExprs[0], &SubExprs[END]);
205   }
206 };
207 
208 /// \brief Representation of a Microsoft __if_exists or __if_not_exists
209 /// statement with a dependent name.
210 ///
211 /// The __if_exists statement can be used to include a sequence of statements
212 /// in the program only when a particular dependent name does not exist. For
213 /// example:
214 ///
215 /// \code
216 /// template<typename T>
217 /// void call_foo(T &t) {
218 ///   __if_exists (T::foo) {
219 ///     t.foo(); // okay: only called when T::foo exists.
220 ///   }
221 /// }
222 /// \endcode
223 ///
224 /// Similarly, the __if_not_exists statement can be used to include the
225 /// statements when a particular name does not exist.
226 ///
227 /// Note that this statement only captures __if_exists and __if_not_exists
228 /// statements whose name is dependent. All non-dependent cases are handled
229 /// directly in the parser, so that they don't introduce a new scope. Clang
230 /// introduces scopes in the dependent case to keep names inside the compound
231 /// statement from leaking out into the surround statements, which would
232 /// compromise the template instantiation model. This behavior differs from
233 /// Visual C++ (which never introduces a scope), but is a fairly reasonable
234 /// approximation of the VC++ behavior.
235 class MSDependentExistsStmt : public Stmt {
236   SourceLocation KeywordLoc;
237   bool IsIfExists;
238   NestedNameSpecifierLoc QualifierLoc;
239   DeclarationNameInfo NameInfo;
240   Stmt *SubStmt;
241 
242   friend class ASTReader;
243   friend class ASTStmtReader;
244 
245 public:
MSDependentExistsStmt(SourceLocation KeywordLoc,bool IsIfExists,NestedNameSpecifierLoc QualifierLoc,DeclarationNameInfo NameInfo,CompoundStmt * SubStmt)246   MSDependentExistsStmt(SourceLocation KeywordLoc, bool IsIfExists,
247                         NestedNameSpecifierLoc QualifierLoc,
248                         DeclarationNameInfo NameInfo,
249                         CompoundStmt *SubStmt)
250   : Stmt(MSDependentExistsStmtClass),
251     KeywordLoc(KeywordLoc), IsIfExists(IsIfExists),
252     QualifierLoc(QualifierLoc), NameInfo(NameInfo),
253     SubStmt(reinterpret_cast<Stmt *>(SubStmt)) { }
254 
255   /// \brief Retrieve the location of the __if_exists or __if_not_exists
256   /// keyword.
getKeywordLoc()257   SourceLocation getKeywordLoc() const { return KeywordLoc; }
258 
259   /// \brief Determine whether this is an __if_exists statement.
isIfExists()260   bool isIfExists() const { return IsIfExists; }
261 
262   /// \brief Determine whether this is an __if_exists statement.
isIfNotExists()263   bool isIfNotExists() const { return !IsIfExists; }
264 
265   /// \brief Retrieve the nested-name-specifier that qualifies this name, if
266   /// any.
getQualifierLoc()267   NestedNameSpecifierLoc getQualifierLoc() const { return QualifierLoc; }
268 
269   /// \brief Retrieve the name of the entity we're testing for, along with
270   /// location information
getNameInfo()271   DeclarationNameInfo getNameInfo() const { return NameInfo; }
272 
273   /// \brief Retrieve the compound statement that will be included in the
274   /// program only if the existence of the symbol matches the initial keyword.
getSubStmt()275   CompoundStmt *getSubStmt() const {
276     return reinterpret_cast<CompoundStmt *>(SubStmt);
277   }
278 
getLocStart()279   SourceLocation getLocStart() const LLVM_READONLY { return KeywordLoc; }
getLocEnd()280   SourceLocation getLocEnd() const LLVM_READONLY { return SubStmt->getLocEnd();}
281 
children()282   child_range children() {
283     return child_range(&SubStmt, &SubStmt+1);
284   }
285 
classof(const Stmt * T)286   static bool classof(const Stmt *T) {
287     return T->getStmtClass() == MSDependentExistsStmtClass;
288   }
289 };
290 
291 /// \brief Represents the body of a coroutine. This wraps the normal function
292 /// body and holds the additional semantic context required to set up and tear
293 /// down the coroutine frame.
294 class CoroutineBodyStmt : public Stmt {
295   enum SubStmt {
296     Body,          ///< The body of the coroutine.
297     Promise,       ///< The promise statement.
298     InitSuspend,   ///< The initial suspend statement, run before the body.
299     FinalSuspend,  ///< The final suspend statement, run after the body.
300     OnException,   ///< Handler for exceptions thrown in the body.
301     OnFallthrough, ///< Handler for control flow falling off the body.
302     ReturnValue,   ///< Return value for thunk function.
303     FirstParamMove ///< First offset for move construction of parameter copies.
304   };
305   Stmt *SubStmts[SubStmt::FirstParamMove];
306 
307   friend class ASTStmtReader;
308 public:
CoroutineBodyStmt(Stmt * Body,Stmt * Promise,Stmt * InitSuspend,Stmt * FinalSuspend,Stmt * OnException,Stmt * OnFallthrough,Expr * ReturnValue,ArrayRef<Expr * > ParamMoves)309   CoroutineBodyStmt(Stmt *Body, Stmt *Promise, Stmt *InitSuspend,
310                     Stmt *FinalSuspend, Stmt *OnException, Stmt *OnFallthrough,
311                     Expr *ReturnValue, ArrayRef<Expr *> ParamMoves)
312       : Stmt(CoroutineBodyStmtClass) {
313     SubStmts[CoroutineBodyStmt::Body] = Body;
314     SubStmts[CoroutineBodyStmt::Promise] = Promise;
315     SubStmts[CoroutineBodyStmt::InitSuspend] = InitSuspend;
316     SubStmts[CoroutineBodyStmt::FinalSuspend] = FinalSuspend;
317     SubStmts[CoroutineBodyStmt::OnException] = OnException;
318     SubStmts[CoroutineBodyStmt::OnFallthrough] = OnFallthrough;
319     SubStmts[CoroutineBodyStmt::ReturnValue] = ReturnValue;
320     // FIXME: Tail-allocate space for parameter move expressions and store them.
321     assert(ParamMoves.empty() && "not implemented yet");
322   }
323 
324   /// \brief Retrieve the body of the coroutine as written. This will be either
325   /// a CompoundStmt or a TryStmt.
getBody()326   Stmt *getBody() const {
327     return SubStmts[SubStmt::Body];
328   }
329 
getPromiseDeclStmt()330   Stmt *getPromiseDeclStmt() const { return SubStmts[SubStmt::Promise]; }
getPromiseDecl()331   VarDecl *getPromiseDecl() const {
332     return cast<VarDecl>(cast<DeclStmt>(getPromiseDeclStmt())->getSingleDecl());
333   }
334 
getInitSuspendStmt()335   Stmt *getInitSuspendStmt() const { return SubStmts[SubStmt::InitSuspend]; }
getFinalSuspendStmt()336   Stmt *getFinalSuspendStmt() const { return SubStmts[SubStmt::FinalSuspend]; }
337 
getExceptionHandler()338   Stmt *getExceptionHandler() const { return SubStmts[SubStmt::OnException]; }
getFallthroughHandler()339   Stmt *getFallthroughHandler() const {
340     return SubStmts[SubStmt::OnFallthrough];
341   }
342 
getReturnValueInit()343   Expr *getReturnValueInit() const {
344     return cast<Expr>(SubStmts[SubStmt::ReturnValue]);
345   }
346 
getLocStart()347   SourceLocation getLocStart() const LLVM_READONLY {
348     return getBody()->getLocStart();
349   }
getLocEnd()350   SourceLocation getLocEnd() const LLVM_READONLY {
351     return getBody()->getLocEnd();
352   }
353 
children()354   child_range children() {
355     return child_range(SubStmts, SubStmts + SubStmt::FirstParamMove);
356   }
357 
classof(const Stmt * T)358   static bool classof(const Stmt *T) {
359     return T->getStmtClass() == CoroutineBodyStmtClass;
360   }
361 };
362 
363 /// \brief Represents a 'co_return' statement in the C++ Coroutines TS.
364 ///
365 /// This statament models the initialization of the coroutine promise
366 /// (encapsulating the eventual notional return value) from an expression
367 /// (or braced-init-list), followed by termination of the coroutine.
368 ///
369 /// This initialization is modeled by the evaluation of the operand
370 /// followed by a call to one of:
371 ///   <promise>.return_value(<operand>)
372 ///   <promise>.return_void()
373 /// which we name the "promise call".
374 class CoreturnStmt : public Stmt {
375   SourceLocation CoreturnLoc;
376 
377   enum SubStmt { Operand, PromiseCall, Count };
378   Stmt *SubStmts[SubStmt::Count];
379 
380   friend class ASTStmtReader;
381 public:
CoreturnStmt(SourceLocation CoreturnLoc,Stmt * Operand,Stmt * PromiseCall)382   CoreturnStmt(SourceLocation CoreturnLoc, Stmt *Operand, Stmt *PromiseCall)
383       : Stmt(CoreturnStmtClass), CoreturnLoc(CoreturnLoc) {
384     SubStmts[SubStmt::Operand] = Operand;
385     SubStmts[SubStmt::PromiseCall] = PromiseCall;
386   }
387 
getKeywordLoc()388   SourceLocation getKeywordLoc() const { return CoreturnLoc; }
389 
390   /// \brief Retrieve the operand of the 'co_return' statement. Will be nullptr
391   /// if none was specified.
getOperand()392   Expr *getOperand() const { return static_cast<Expr*>(SubStmts[Operand]); }
393 
394   /// \brief Retrieve the promise call that results from this 'co_return'
395   /// statement. Will be nullptr if either the coroutine has not yet been
396   /// finalized or the coroutine has no eventual return type.
getPromiseCall()397   Expr *getPromiseCall() const {
398     return static_cast<Expr*>(SubStmts[PromiseCall]);
399   }
400 
getLocStart()401   SourceLocation getLocStart() const LLVM_READONLY { return CoreturnLoc; }
getLocEnd()402   SourceLocation getLocEnd() const LLVM_READONLY {
403     return getOperand()->getLocEnd();
404   }
405 
children()406   child_range children() {
407     return child_range(SubStmts, SubStmts + SubStmt::Count);
408   }
409 
classof(const Stmt * T)410   static bool classof(const Stmt *T) {
411     return T->getStmtClass() == CoreturnStmtClass;
412   }
413 };
414 
415 }  // end namespace clang
416 
417 #endif
418