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
23namespace clang {
24
25class VarDecl;
26
27/// CXXCatchStmt - This represents a C++ catch block.
28///
29class CXXCatchStmt : public Stmt {
30  SourceLocation CatchLoc;
31  /// The exception-declaration of the type.
32  VarDecl *ExceptionDecl;
33  /// The handler block.
34  Stmt *HandlerBlock;
35
36public:
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///
65class 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
81public:
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.
128class CXXForRangeStmt : public Stmt {
129  SourceLocation ForLoc;
130  enum { RANGE, BEGINSTMT, ENDSTMT, 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;
139public:
140  CXXForRangeStmt(DeclStmt *Range, DeclStmt *Begin, DeclStmt *End,
141                  Expr *Cond, Expr *Inc, DeclStmt *LoopVar, Stmt *Body,
142                  SourceLocation FL, SourceLocation CAL, SourceLocation CL,
143                  SourceLocation RPL);
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
154  DeclStmt *getRangeStmt() { return cast<DeclStmt>(SubExprs[RANGE]); }
155  DeclStmt *getBeginStmt() {
156    return cast_or_null<DeclStmt>(SubExprs[BEGINSTMT]);
157  }
158  DeclStmt *getEndStmt() { return cast_or_null<DeclStmt>(SubExprs[ENDSTMT]); }
159  Expr *getCond() { return cast_or_null<Expr>(SubExprs[COND]); }
160  Expr *getInc() { return cast_or_null<Expr>(SubExprs[INC]); }
161  DeclStmt *getLoopVarStmt() { return cast<DeclStmt>(SubExprs[LOOPVAR]); }
162  Stmt *getBody() { return SubExprs[BODY]; }
163
164  const DeclStmt *getRangeStmt() const {
165    return cast<DeclStmt>(SubExprs[RANGE]);
166  }
167  const DeclStmt *getBeginStmt() const {
168    return cast_or_null<DeclStmt>(SubExprs[BEGINSTMT]);
169  }
170  const DeclStmt *getEndStmt() const {
171    return cast_or_null<DeclStmt>(SubExprs[ENDSTMT]);
172  }
173  const Expr *getCond() const {
174    return cast_or_null<Expr>(SubExprs[COND]);
175  }
176  const Expr *getInc() const {
177    return cast_or_null<Expr>(SubExprs[INC]);
178  }
179  const DeclStmt *getLoopVarStmt() const {
180    return cast<DeclStmt>(SubExprs[LOOPVAR]);
181  }
182  const Stmt *getBody() const { return SubExprs[BODY]; }
183
184  void setRangeInit(Expr *E) { SubExprs[RANGE] = reinterpret_cast<Stmt*>(E); }
185  void setRangeStmt(Stmt *S) { SubExprs[RANGE] = S; }
186  void setBeginStmt(Stmt *S) { SubExprs[BEGINSTMT] = S; }
187  void setEndStmt(Stmt *S) { SubExprs[ENDSTMT] = S; }
188  void setCond(Expr *E) { SubExprs[COND] = reinterpret_cast<Stmt*>(E); }
189  void setInc(Expr *E) { SubExprs[INC] = reinterpret_cast<Stmt*>(E); }
190  void setLoopVarStmt(Stmt *S) { SubExprs[LOOPVAR] = S; }
191  void setBody(Stmt *S) { SubExprs[BODY] = S; }
192
193  SourceLocation getForLoc() const { return ForLoc; }
194  SourceLocation getCoawaitLoc() const { return CoawaitLoc; }
195  SourceLocation getColonLoc() const { return ColonLoc; }
196  SourceLocation getRParenLoc() const { return RParenLoc; }
197
198  SourceLocation getLocStart() const LLVM_READONLY { return ForLoc; }
199  SourceLocation getLocEnd() const LLVM_READONLY {
200    return SubExprs[BODY]->getLocEnd();
201  }
202
203  static bool classof(const Stmt *T) {
204    return T->getStmtClass() == CXXForRangeStmtClass;
205  }
206
207  // Iterators
208  child_range children() {
209    return child_range(&SubExprs[0], &SubExprs[END]);
210  }
211};
212
213/// \brief Representation of a Microsoft __if_exists or __if_not_exists
214/// statement with a dependent name.
215///
216/// The __if_exists statement can be used to include a sequence of statements
217/// in the program only when a particular dependent name does not exist. For
218/// example:
219///
220/// \code
221/// template<typename T>
222/// void call_foo(T &t) {
223///   __if_exists (T::foo) {
224///     t.foo(); // okay: only called when T::foo exists.
225///   }
226/// }
227/// \endcode
228///
229/// Similarly, the __if_not_exists statement can be used to include the
230/// statements when a particular name does not exist.
231///
232/// Note that this statement only captures __if_exists and __if_not_exists
233/// statements whose name is dependent. All non-dependent cases are handled
234/// directly in the parser, so that they don't introduce a new scope. Clang
235/// introduces scopes in the dependent case to keep names inside the compound
236/// statement from leaking out into the surround statements, which would
237/// compromise the template instantiation model. This behavior differs from
238/// Visual C++ (which never introduces a scope), but is a fairly reasonable
239/// approximation of the VC++ behavior.
240class MSDependentExistsStmt : public Stmt {
241  SourceLocation KeywordLoc;
242  bool IsIfExists;
243  NestedNameSpecifierLoc QualifierLoc;
244  DeclarationNameInfo NameInfo;
245  Stmt *SubStmt;
246
247  friend class ASTReader;
248  friend class ASTStmtReader;
249
250public:
251  MSDependentExistsStmt(SourceLocation KeywordLoc, bool IsIfExists,
252                        NestedNameSpecifierLoc QualifierLoc,
253                        DeclarationNameInfo NameInfo,
254                        CompoundStmt *SubStmt)
255  : Stmt(MSDependentExistsStmtClass),
256    KeywordLoc(KeywordLoc), IsIfExists(IsIfExists),
257    QualifierLoc(QualifierLoc), NameInfo(NameInfo),
258    SubStmt(reinterpret_cast<Stmt *>(SubStmt)) { }
259
260  /// \brief Retrieve the location of the __if_exists or __if_not_exists
261  /// keyword.
262  SourceLocation getKeywordLoc() const { return KeywordLoc; }
263
264  /// \brief Determine whether this is an __if_exists statement.
265  bool isIfExists() const { return IsIfExists; }
266
267  /// \brief Determine whether this is an __if_exists statement.
268  bool isIfNotExists() const { return !IsIfExists; }
269
270  /// \brief Retrieve the nested-name-specifier that qualifies this name, if
271  /// any.
272  NestedNameSpecifierLoc getQualifierLoc() const { return QualifierLoc; }
273
274  /// \brief Retrieve the name of the entity we're testing for, along with
275  /// location information
276  DeclarationNameInfo getNameInfo() const { return NameInfo; }
277
278  /// \brief Retrieve the compound statement that will be included in the
279  /// program only if the existence of the symbol matches the initial keyword.
280  CompoundStmt *getSubStmt() const {
281    return reinterpret_cast<CompoundStmt *>(SubStmt);
282  }
283
284  SourceLocation getLocStart() const LLVM_READONLY { return KeywordLoc; }
285  SourceLocation getLocEnd() const LLVM_READONLY { return SubStmt->getLocEnd();}
286
287  child_range children() {
288    return child_range(&SubStmt, &SubStmt+1);
289  }
290
291  static bool classof(const Stmt *T) {
292    return T->getStmtClass() == MSDependentExistsStmtClass;
293  }
294};
295
296/// \brief Represents the body of a coroutine. This wraps the normal function
297/// body and holds the additional semantic context required to set up and tear
298/// down the coroutine frame.
299class CoroutineBodyStmt : public Stmt {
300  enum SubStmt {
301    Body,          ///< The body of the coroutine.
302    Promise,       ///< The promise statement.
303    InitSuspend,   ///< The initial suspend statement, run before the body.
304    FinalSuspend,  ///< The final suspend statement, run after the body.
305    OnException,   ///< Handler for exceptions thrown in the body.
306    OnFallthrough, ///< Handler for control flow falling off the body.
307    ReturnValue,   ///< Return value for thunk function.
308    FirstParamMove ///< First offset for move construction of parameter copies.
309  };
310  Stmt *SubStmts[SubStmt::FirstParamMove];
311
312  friend class ASTStmtReader;
313public:
314  CoroutineBodyStmt(Stmt *Body, Stmt *Promise, Stmt *InitSuspend,
315                    Stmt *FinalSuspend, Stmt *OnException, Stmt *OnFallthrough,
316                    Expr *ReturnValue, ArrayRef<Expr *> ParamMoves)
317      : Stmt(CoroutineBodyStmtClass) {
318    SubStmts[CoroutineBodyStmt::Body] = Body;
319    SubStmts[CoroutineBodyStmt::Promise] = Promise;
320    SubStmts[CoroutineBodyStmt::InitSuspend] = InitSuspend;
321    SubStmts[CoroutineBodyStmt::FinalSuspend] = FinalSuspend;
322    SubStmts[CoroutineBodyStmt::OnException] = OnException;
323    SubStmts[CoroutineBodyStmt::OnFallthrough] = OnFallthrough;
324    SubStmts[CoroutineBodyStmt::ReturnValue] = ReturnValue;
325    // FIXME: Tail-allocate space for parameter move expressions and store them.
326    assert(ParamMoves.empty() && "not implemented yet");
327  }
328
329  /// \brief Retrieve the body of the coroutine as written. This will be either
330  /// a CompoundStmt or a TryStmt.
331  Stmt *getBody() const {
332    return SubStmts[SubStmt::Body];
333  }
334
335  Stmt *getPromiseDeclStmt() const { return SubStmts[SubStmt::Promise]; }
336  VarDecl *getPromiseDecl() const {
337    return cast<VarDecl>(cast<DeclStmt>(getPromiseDeclStmt())->getSingleDecl());
338  }
339
340  Stmt *getInitSuspendStmt() const { return SubStmts[SubStmt::InitSuspend]; }
341  Stmt *getFinalSuspendStmt() const { return SubStmts[SubStmt::FinalSuspend]; }
342
343  Stmt *getExceptionHandler() const { return SubStmts[SubStmt::OnException]; }
344  Stmt *getFallthroughHandler() const {
345    return SubStmts[SubStmt::OnFallthrough];
346  }
347
348  Expr *getReturnValueInit() const {
349    return cast<Expr>(SubStmts[SubStmt::ReturnValue]);
350  }
351
352  SourceLocation getLocStart() const LLVM_READONLY {
353    return getBody()->getLocStart();
354  }
355  SourceLocation getLocEnd() const LLVM_READONLY {
356    return getBody()->getLocEnd();
357  }
358
359  child_range children() {
360    return child_range(SubStmts, SubStmts + SubStmt::FirstParamMove);
361  }
362
363  static bool classof(const Stmt *T) {
364    return T->getStmtClass() == CoroutineBodyStmtClass;
365  }
366};
367
368/// \brief Represents a 'co_return' statement in the C++ Coroutines TS.
369///
370/// This statament models the initialization of the coroutine promise
371/// (encapsulating the eventual notional return value) from an expression
372/// (or braced-init-list), followed by termination of the coroutine.
373///
374/// This initialization is modeled by the evaluation of the operand
375/// followed by a call to one of:
376///   <promise>.return_value(<operand>)
377///   <promise>.return_void()
378/// which we name the "promise call".
379class CoreturnStmt : public Stmt {
380  SourceLocation CoreturnLoc;
381
382  enum SubStmt { Operand, PromiseCall, Count };
383  Stmt *SubStmts[SubStmt::Count];
384
385  friend class ASTStmtReader;
386public:
387  CoreturnStmt(SourceLocation CoreturnLoc, Stmt *Operand, Stmt *PromiseCall)
388      : Stmt(CoreturnStmtClass), CoreturnLoc(CoreturnLoc) {
389    SubStmts[SubStmt::Operand] = Operand;
390    SubStmts[SubStmt::PromiseCall] = PromiseCall;
391  }
392
393  SourceLocation getKeywordLoc() const { return CoreturnLoc; }
394
395  /// \brief Retrieve the operand of the 'co_return' statement. Will be nullptr
396  /// if none was specified.
397  Expr *getOperand() const { return static_cast<Expr*>(SubStmts[Operand]); }
398
399  /// \brief Retrieve the promise call that results from this 'co_return'
400  /// statement. Will be nullptr if either the coroutine has not yet been
401  /// finalized or the coroutine has no eventual return type.
402  Expr *getPromiseCall() const {
403    return static_cast<Expr*>(SubStmts[PromiseCall]);
404  }
405
406  SourceLocation getLocStart() const LLVM_READONLY { return CoreturnLoc; }
407  SourceLocation getLocEnd() const LLVM_READONLY {
408    return getOperand()->getLocEnd();
409  }
410
411  child_range children() {
412    return child_range(SubStmts, SubStmts + SubStmt::Count);
413  }
414
415  static bool classof(const Stmt *T) {
416    return T->getStmtClass() == CoreturnStmtClass;
417  }
418};
419
420}  // end namespace clang
421
422#endif
423