1//===--- StmtCXX.h - Classes for representing C++ statements ----*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file defines the C++ statement AST node classes.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_CLANG_AST_STMTCXX_H
14#define LLVM_CLANG_AST_STMTCXX_H
15
16#include "clang/AST/DeclarationName.h"
17#include "clang/AST/Expr.h"
18#include "clang/AST/NestedNameSpecifier.h"
19#include "clang/AST/Stmt.h"
20#include "llvm/Support/Compiler.h"
21
22namespace clang {
23
24class VarDecl;
25
26/// CXXCatchStmt - This represents a C++ catch block.
27///
28class CXXCatchStmt : public Stmt {
29 SourceLocation CatchLoc;
30 /// The exception-declaration of the type.
31 VarDecl *ExceptionDecl;
32 /// The handler block.
33 Stmt *HandlerBlock;
34
35public:
36 CXXCatchStmt(SourceLocation catchLoc, VarDecl *exDecl, Stmt *handlerBlock)
37 : Stmt(CXXCatchStmtClass), CatchLoc(catchLoc), ExceptionDecl(exDecl),
38 HandlerBlock(handlerBlock) {}
39
40 CXXCatchStmt(EmptyShell Empty)
41 : Stmt(CXXCatchStmtClass), ExceptionDecl(nullptr), HandlerBlock(nullptr) {}
42
43 SourceLocation getBeginLoc() const LLVM_READONLY { return CatchLoc; }
44 SourceLocation getEndLoc() const LLVM_READONLY {
45 return HandlerBlock->getEndLoc();
46 }
47
48 SourceLocation getCatchLoc() const { return CatchLoc; }
49 VarDecl *getExceptionDecl() const { return ExceptionDecl; }
50 QualType getCaughtType() const;
51 Stmt *getHandlerBlock() const { return HandlerBlock; }
52
53 static bool classof(const Stmt *T) {
54 return T->getStmtClass() == CXXCatchStmtClass;
55 }
56
57 child_range children() { return child_range(&HandlerBlock, &HandlerBlock+1); }
58
59 const_child_range children() const {
60 return const_child_range(&HandlerBlock, &HandlerBlock + 1);
61 }
62
63 friend class ASTStmtReader;
64};
65
66/// CXXTryStmt - A C++ try block, including all handlers.
67///
68class CXXTryStmt final : public Stmt,
69 private llvm::TrailingObjects<CXXTryStmt, Stmt *> {
70
71 friend TrailingObjects;
72 friend class ASTStmtReader;
73
74 SourceLocation TryLoc;
75 unsigned NumHandlers;
76 size_t numTrailingObjects(OverloadToken<Stmt *>) const { return NumHandlers; }
77
78 CXXTryStmt(SourceLocation tryLoc, Stmt *tryBlock, ArrayRef<Stmt*> handlers);
79 CXXTryStmt(EmptyShell Empty, unsigned numHandlers)
80 : Stmt(CXXTryStmtClass), NumHandlers(numHandlers) { }
81
82 Stmt *const *getStmts() const { return getTrailingObjects<Stmt *>(); }
83 Stmt **getStmts() { return getTrailingObjects<Stmt *>(); }
84
85public:
86 static CXXTryStmt *Create(const ASTContext &C, SourceLocation tryLoc,
87 Stmt *tryBlock, ArrayRef<Stmt*> handlers);
88
89 static CXXTryStmt *Create(const ASTContext &C, EmptyShell Empty,
90 unsigned numHandlers);
91
92 SourceLocation getBeginLoc() const LLVM_READONLY { return getTryLoc(); }
93
94 SourceLocation getTryLoc() const { return TryLoc; }
95 SourceLocation getEndLoc() const {
96 return getStmts()[NumHandlers]->getEndLoc();
97 }
98
99 CompoundStmt *getTryBlock() {
100 return cast<CompoundStmt>(getStmts()[0]);
101 }
102 const CompoundStmt *getTryBlock() const {
103 return cast<CompoundStmt>(getStmts()[0]);
104 }
105
106 unsigned getNumHandlers() const { return NumHandlers; }
107 CXXCatchStmt *getHandler(unsigned i) {
108 return cast<CXXCatchStmt>(getStmts()[i + 1]);
109 }
110 const CXXCatchStmt *getHandler(unsigned i) const {
111 return cast<CXXCatchStmt>(getStmts()[i + 1]);
112 }
113
114 static bool classof(const Stmt *T) {
115 return T->getStmtClass() == CXXTryStmtClass;
116 }
117
118 child_range children() {
119 return child_range(getStmts(), getStmts() + getNumHandlers() + 1);
120 }
121
122 const_child_range children() const {
123 return const_child_range(getStmts(), getStmts() + getNumHandlers() + 1);
124 }
125};
126
127/// CXXForRangeStmt - This represents C++0x [stmt.ranged]'s ranged for
128/// statement, represented as 'for (range-declarator : range-expression)'
129/// or 'for (init-statement range-declarator : range-expression)'.
130///
131/// This is stored in a partially-desugared form to allow full semantic
132/// analysis of the constituent components. The original syntactic components
133/// can be extracted using getLoopVariable and getRangeInit.
134class CXXForRangeStmt : public Stmt {
135 SourceLocation ForLoc;
136 enum { INIT, RANGE, BEGINSTMT, ENDSTMT, COND, INC, LOOPVAR, BODY, END };
137 // SubExprs[RANGE] is an expression or declstmt.
138 // SubExprs[COND] and SubExprs[INC] are expressions.
139 Stmt *SubExprs[END];
140 SourceLocation CoawaitLoc;
141 SourceLocation ColonLoc;
142 SourceLocation RParenLoc;
143
144 friend class ASTStmtReader;
145public:
146 CXXForRangeStmt(Stmt *InitStmt, DeclStmt *Range, DeclStmt *Begin,
147 DeclStmt *End, Expr *Cond, Expr *Inc, DeclStmt *LoopVar,
148 Stmt *Body, SourceLocation FL, SourceLocation CAL,
149 SourceLocation CL, SourceLocation RPL);
150 CXXForRangeStmt(EmptyShell Empty) : Stmt(CXXForRangeStmtClass, Empty) { }
151
152 Stmt *getInit() { return SubExprs[INIT]; }
153 VarDecl *getLoopVariable();
154 Expr *getRangeInit();
155
156 const Stmt *getInit() const { return SubExprs[INIT]; }
157 const VarDecl *getLoopVariable() const;
158 const Expr *getRangeInit() const;
159
160
161 DeclStmt *getRangeStmt() { return cast<DeclStmt>(SubExprs[RANGE]); }
162 DeclStmt *getBeginStmt() {
163 return cast_or_null<DeclStmt>(SubExprs[BEGINSTMT]);
164 }
165 DeclStmt *getEndStmt() { return cast_or_null<DeclStmt>(SubExprs[ENDSTMT]); }
166 Expr *getCond() { return cast_or_null<Expr>(SubExprs[COND]); }
167 Expr *getInc() { return cast_or_null<Expr>(SubExprs[INC]); }
168 DeclStmt *getLoopVarStmt() { return cast<DeclStmt>(SubExprs[LOOPVAR]); }
169 Stmt *getBody() { return SubExprs[BODY]; }
170
171 const DeclStmt *getRangeStmt() const {
172 return cast<DeclStmt>(SubExprs[RANGE]);
173 }
174 const DeclStmt *getBeginStmt() const {
175 return cast_or_null<DeclStmt>(SubExprs[BEGINSTMT]);
176 }
177 const DeclStmt *getEndStmt() const {
178 return cast_or_null<DeclStmt>(SubExprs[ENDSTMT]);
179 }
180 const Expr *getCond() const {
181 return cast_or_null<Expr>(SubExprs[COND]);
182 }
183 const Expr *getInc() const {
184 return cast_or_null<Expr>(SubExprs[INC]);
185 }
186 const DeclStmt *getLoopVarStmt() const {
187 return cast<DeclStmt>(SubExprs[LOOPVAR]);
188 }
189 const Stmt *getBody() const { return SubExprs[BODY]; }
190
191 void setInit(Stmt *S) { SubExprs[INIT] = S; }
192 void setRangeInit(Expr *E) { SubExprs[RANGE] = reinterpret_cast<Stmt*>(E); }
193 void setRangeStmt(Stmt *S) { SubExprs[RANGE] = S; }
194 void setBeginStmt(Stmt *S) { SubExprs[BEGINSTMT] = S; }
195 void setEndStmt(Stmt *S) { SubExprs[ENDSTMT] = S; }
196 void setCond(Expr *E) { SubExprs[COND] = reinterpret_cast<Stmt*>(E); }
197 void setInc(Expr *E) { SubExprs[INC] = reinterpret_cast<Stmt*>(E); }
198 void setLoopVarStmt(Stmt *S) { SubExprs[LOOPVAR] = S; }
199 void setBody(Stmt *S) { SubExprs[BODY] = S; }
200
201 SourceLocation getForLoc() const { return ForLoc; }
202 SourceLocation getCoawaitLoc() const { return CoawaitLoc; }
203 SourceLocation getColonLoc() const { return ColonLoc; }
204 SourceLocation getRParenLoc() const { return RParenLoc; }
205
206 SourceLocation getBeginLoc() const LLVM_READONLY { return ForLoc; }
207 SourceLocation getEndLoc() const LLVM_READONLY {
208 return SubExprs[BODY]->getEndLoc();
209 }
210
211 static bool classof(const Stmt *T) {
212 return T->getStmtClass() == CXXForRangeStmtClass;
213 }
214
215 // Iterators
216 child_range children() {
217 return child_range(&SubExprs[0], &SubExprs[END]);
218 }
219
220 const_child_range children() const {
221 return const_child_range(&SubExprs[0], &SubExprs[END]);
222 }
223};
224
225/// Representation of a Microsoft __if_exists or __if_not_exists
226/// statement with a dependent name.
227///
228/// The __if_exists statement can be used to include a sequence of statements
229/// in the program only when a particular dependent name does not exist. For
230/// example:
231///
232/// \code
233/// template<typename T>
234/// void call_foo(T &t) {
235/// __if_exists (T::foo) {
236/// t.foo(); // okay: only called when T::foo exists.
237/// }
238/// }
239/// \endcode
240///
241/// Similarly, the __if_not_exists statement can be used to include the
242/// statements when a particular name does not exist.
243///
244/// Note that this statement only captures __if_exists and __if_not_exists
245/// statements whose name is dependent. All non-dependent cases are handled
246/// directly in the parser, so that they don't introduce a new scope. Clang
247/// introduces scopes in the dependent case to keep names inside the compound
248/// statement from leaking out into the surround statements, which would
249/// compromise the template instantiation model. This behavior differs from
250/// Visual C++ (which never introduces a scope), but is a fairly reasonable
251/// approximation of the VC++ behavior.
252class MSDependentExistsStmt : public Stmt {
253 SourceLocation KeywordLoc;
254 bool IsIfExists;
255 NestedNameSpecifierLoc QualifierLoc;
256 DeclarationNameInfo NameInfo;
257 Stmt *SubStmt;
258
259 friend class ASTReader;
260 friend class ASTStmtReader;
261
262public:
263 MSDependentExistsStmt(SourceLocation KeywordLoc, bool IsIfExists,
264 NestedNameSpecifierLoc QualifierLoc,
265 DeclarationNameInfo NameInfo,
266 CompoundStmt *SubStmt)
267 : Stmt(MSDependentExistsStmtClass),
268 KeywordLoc(KeywordLoc), IsIfExists(IsIfExists),
269 QualifierLoc(QualifierLoc), NameInfo(NameInfo),
270 SubStmt(reinterpret_cast<Stmt *>(SubStmt)) { }
271
272 /// Retrieve the location of the __if_exists or __if_not_exists
273 /// keyword.
274 SourceLocation getKeywordLoc() const { return KeywordLoc; }
275
276 /// Determine whether this is an __if_exists statement.
277 bool isIfExists() const { return IsIfExists; }
278
279 /// Determine whether this is an __if_exists statement.
280 bool isIfNotExists() const { return !IsIfExists; }
281
282 /// Retrieve the nested-name-specifier that qualifies this name, if
283 /// any.
284 NestedNameSpecifierLoc getQualifierLoc() const { return QualifierLoc; }
285
286 /// Retrieve the name of the entity we're testing for, along with
287 /// location information
288 DeclarationNameInfo getNameInfo() const { return NameInfo; }
289
290 /// Retrieve the compound statement that will be included in the
291 /// program only if the existence of the symbol matches the initial keyword.
292 CompoundStmt *getSubStmt() const {
293 return reinterpret_cast<CompoundStmt *>(SubStmt);
294 }
295
296 SourceLocation getBeginLoc() const LLVM_READONLY { return KeywordLoc; }
297 SourceLocation getEndLoc() const LLVM_READONLY {
298 return SubStmt->getEndLoc();
299 }
300
301 child_range children() {
302 return child_range(&SubStmt, &SubStmt+1);
303 }
304
305 const_child_range children() const {
306 return const_child_range(&SubStmt, &SubStmt + 1);
307 }
308
309 static bool classof(const Stmt *T) {
310 return T->getStmtClass() == MSDependentExistsStmtClass;
311 }
312};
313
314/// Represents the body of a coroutine. This wraps the normal function
315/// body and holds the additional semantic context required to set up and tear
316/// down the coroutine frame.
317class CoroutineBodyStmt final
318 : public Stmt,
319 private llvm::TrailingObjects<CoroutineBodyStmt, Stmt *> {
320 enum SubStmt {
321 Body, ///< The body of the coroutine.
322 Promise, ///< The promise statement.
323 InitSuspend, ///< The initial suspend statement, run before the body.
324 FinalSuspend, ///< The final suspend statement, run after the body.
325 OnException, ///< Handler for exceptions thrown in the body.
326 OnFallthrough, ///< Handler for control flow falling off the body.
327 Allocate, ///< Coroutine frame memory allocation.
328 Deallocate, ///< Coroutine frame memory deallocation.
329 ReturnValue, ///< Return value for thunk function: p.get_return_object().
330 ResultDecl, ///< Declaration holding the result of get_return_object.
331 ReturnStmt, ///< Return statement for the thunk function.
332 ReturnStmtOnAllocFailure, ///< Return statement if allocation failed.
333 FirstParamMove ///< First offset for move construction of parameter copies.
334 };
335 unsigned NumParams;
336
337 friend class ASTStmtReader;
338 friend class ASTReader;
339 friend TrailingObjects;
340
341 Stmt **getStoredStmts() { return getTrailingObjects<Stmt *>(); }
342
343 Stmt *const *getStoredStmts() const { return getTrailingObjects<Stmt *>(); }
344
345public:
346
347 struct CtorArgs {
348 Stmt *Body = nullptr;
349 Stmt *Promise = nullptr;
350 Expr *InitialSuspend = nullptr;
351 Expr *FinalSuspend = nullptr;
352 Stmt *OnException = nullptr;
353 Stmt *OnFallthrough = nullptr;
354 Expr *Allocate = nullptr;
355 Expr *Deallocate = nullptr;
356 Expr *ReturnValue = nullptr;
357 Stmt *ResultDecl = nullptr;
358 Stmt *ReturnStmt = nullptr;
359 Stmt *ReturnStmtOnAllocFailure = nullptr;
360 ArrayRef<Stmt *> ParamMoves;
361 };
362
363private:
364
365 CoroutineBodyStmt(CtorArgs const& Args);
366
367public:
368 static CoroutineBodyStmt *Create(const ASTContext &C, CtorArgs const &Args);
369 static CoroutineBodyStmt *Create(const ASTContext &C, EmptyShell,
370 unsigned NumParams);
371
372 bool hasDependentPromiseType() const {
373 return getPromiseDecl()->getType()->isDependentType();
374 }
375
376 /// Retrieve the body of the coroutine as written. This will be either
377 /// a CompoundStmt or a TryStmt.
378 Stmt *getBody() const {
379 return getStoredStmts()[SubStmt::Body];
380 }
381
382 Stmt *getPromiseDeclStmt() const {
383 return getStoredStmts()[SubStmt::Promise];
384 }
385 VarDecl *getPromiseDecl() const {
386 return cast<VarDecl>(cast<DeclStmt>(getPromiseDeclStmt())->getSingleDecl());
387 }
388
389 Stmt *getInitSuspendStmt() const {
390 return getStoredStmts()[SubStmt::InitSuspend];
391 }
392 Stmt *getFinalSuspendStmt() const {
393 return getStoredStmts()[SubStmt::FinalSuspend];
394 }
395
396 Stmt *getExceptionHandler() const {
397 return getStoredStmts()[SubStmt::OnException];
398 }
399 Stmt *getFallthroughHandler() const {
400 return getStoredStmts()[SubStmt::OnFallthrough];
401 }
402
403 Expr *getAllocate() const {
404 return cast_or_null<Expr>(getStoredStmts()[SubStmt::Allocate]);
405 }
406 Expr *getDeallocate() const {
407 return cast_or_null<Expr>(getStoredStmts()[SubStmt::Deallocate]);
408 }
409 Expr *getReturnValueInit() const {
410 return cast<Expr>(getStoredStmts()[SubStmt::ReturnValue]);
411 }
412 Stmt *getResultDecl() const { return getStoredStmts()[SubStmt::ResultDecl]; }
413 Stmt *getReturnStmt() const { return getStoredStmts()[SubStmt::ReturnStmt]; }
414 Stmt *getReturnStmtOnAllocFailure() const {
415 return getStoredStmts()[SubStmt::ReturnStmtOnAllocFailure];
416 }
417 ArrayRef<Stmt const *> getParamMoves() const {
418 return {getStoredStmts() + SubStmt::FirstParamMove, NumParams};
419 }
420
421 SourceLocation getBeginLoc() const LLVM_READONLY {
422 return getBody() ? getBody()->getBeginLoc()
423 : getPromiseDecl()->getBeginLoc();
424 }
425 SourceLocation getEndLoc() const LLVM_READONLY {
426 return getBody() ? getBody()->getEndLoc() : getPromiseDecl()->getEndLoc();
427 }
428
429 child_range children() {
430 return child_range(getStoredStmts(),
431 getStoredStmts() + SubStmt::FirstParamMove + NumParams);
432 }
433
434 const_child_range children() const {
435 return const_child_range(getStoredStmts(), getStoredStmts() +
436 SubStmt::FirstParamMove +
437 NumParams);
438 }
439
440 static bool classof(const Stmt *T) {
441 return T->getStmtClass() == CoroutineBodyStmtClass;
442 }
443};
444
445/// Represents a 'co_return' statement in the C++ Coroutines TS.
446///
447/// This statament models the initialization of the coroutine promise
448/// (encapsulating the eventual notional return value) from an expression
449/// (or braced-init-list), followed by termination of the coroutine.
450///
451/// This initialization is modeled by the evaluation of the operand
452/// followed by a call to one of:
453/// <promise>.return_value(<operand>)
454/// <promise>.return_void()
455/// which we name the "promise call".
456class CoreturnStmt : public Stmt {
457 SourceLocation CoreturnLoc;
458
459 enum SubStmt { Operand, PromiseCall, Count };
460 Stmt *SubStmts[SubStmt::Count];
461
462 bool IsImplicit : 1;
463
464 friend class ASTStmtReader;
465public:
466 CoreturnStmt(SourceLocation CoreturnLoc, Stmt *Operand, Stmt *PromiseCall,
467 bool IsImplicit = false)
468 : Stmt(CoreturnStmtClass), CoreturnLoc(CoreturnLoc),
469 IsImplicit(IsImplicit) {
470 SubStmts[SubStmt::Operand] = Operand;
471 SubStmts[SubStmt::PromiseCall] = PromiseCall;
472 }
473
474 CoreturnStmt(EmptyShell) : CoreturnStmt({}, {}, {}) {}
475
476 SourceLocation getKeywordLoc() const { return CoreturnLoc; }
477
478 /// Retrieve the operand of the 'co_return' statement. Will be nullptr
479 /// if none was specified.
480 Expr *getOperand() const { return static_cast<Expr*>(SubStmts[Operand]); }
481
482 /// Retrieve the promise call that results from this 'co_return'
483 /// statement. Will be nullptr if either the coroutine has not yet been
484 /// finalized or the coroutine has no eventual return type.
485 Expr *getPromiseCall() const {
486 return static_cast<Expr*>(SubStmts[PromiseCall]);
487 }
488
489 bool isImplicit() const { return IsImplicit; }
490 void setIsImplicit(bool value = true) { IsImplicit = value; }
491
492 SourceLocation getBeginLoc() const LLVM_READONLY { return CoreturnLoc; }
493 SourceLocation getEndLoc() const LLVM_READONLY {
494 return getOperand() ? getOperand()->getEndLoc() : getBeginLoc();
495 }
496
497 child_range children() {
498 if (!getOperand())
499 return child_range(SubStmts + SubStmt::PromiseCall,
500 SubStmts + SubStmt::Count);
501 return child_range(SubStmts, SubStmts + SubStmt::Count);
502 }
503
504 const_child_range children() const {
505 if (!getOperand())
506 return const_child_range(SubStmts + SubStmt::PromiseCall,
507 SubStmts + SubStmt::Count);
508 return const_child_range(SubStmts, SubStmts + SubStmt::Count);
509 }
510
511 static bool classof(const Stmt *T) {
512 return T->getStmtClass() == CoreturnStmtClass;
513 }
514};
515
516} // end namespace clang
517
518#endif
519