Bug Summary

File:clang/lib/CodeGen/CGCoroutine.cpp
Warning:line 95, column 21
Called C++ object pointer is null

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name CGCoroutine.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mthread-model posix -mframe-pointer=none -relaxed-aliasing -fmath-errno -fno-rounding-math -masm-verbose -mconstructor-aliases -munwind-tables -target-cpu x86-64 -dwarf-column-info -fno-split-dwarf-inlining -debugger-tuning=gdb -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-11/lib/clang/11.0.0 -D CLANG_VENDOR="Debian " -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/build-llvm/tools/clang/lib/CodeGen -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/include -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/build-llvm/include -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-11/lib/clang/11.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/build-llvm/tools/clang/lib/CodeGen -fdebug-prefix-map=/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347=. -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -fobjc-runtime=gcc -fno-common -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -o /tmp/scan-build-2020-03-09-184146-41876-1 -x c++ /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGCoroutine.cpp

/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGCoroutine.cpp

1//===----- CGCoroutine.cpp - Emit LLVM Code for C++ coroutines ------------===//
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 contains code dealing with C++ code generation of coroutines.
10//
11//===----------------------------------------------------------------------===//
12
13#include "CGCleanup.h"
14#include "CodeGenFunction.h"
15#include "llvm/ADT/ScopeExit.h"
16#include "clang/AST/StmtCXX.h"
17#include "clang/AST/StmtVisitor.h"
18
19using namespace clang;
20using namespace CodeGen;
21
22using llvm::Value;
23using llvm::BasicBlock;
24
25namespace {
26enum class AwaitKind { Init, Normal, Yield, Final };
27static constexpr llvm::StringLiteral AwaitKindStr[] = {"init", "await", "yield",
28 "final"};
29}
30
31struct clang::CodeGen::CGCoroData {
32 // What is the current await expression kind and how many
33 // await/yield expressions were encountered so far.
34 // These are used to generate pretty labels for await expressions in LLVM IR.
35 AwaitKind CurrentAwaitKind = AwaitKind::Init;
36 unsigned AwaitNum = 0;
37 unsigned YieldNum = 0;
38
39 // How many co_return statements are in the coroutine. Used to decide whether
40 // we need to add co_return; equivalent at the end of the user authored body.
41 unsigned CoreturnCount = 0;
42
43 // A branch to this block is emitted when coroutine needs to suspend.
44 llvm::BasicBlock *SuspendBB = nullptr;
45
46 // The promise type's 'unhandled_exception' handler, if it defines one.
47 Stmt *ExceptionHandler = nullptr;
48
49 // A temporary i1 alloca that stores whether 'await_resume' threw an
50 // exception. If it did, 'true' is stored in this variable, and the coroutine
51 // body must be skipped. If the promise type does not define an exception
52 // handler, this is null.
53 llvm::Value *ResumeEHVar = nullptr;
54
55 // Stores the jump destination just before the coroutine memory is freed.
56 // This is the destination that every suspend point jumps to for the cleanup
57 // branch.
58 CodeGenFunction::JumpDest CleanupJD;
59
60 // Stores the jump destination just before the final suspend. The co_return
61 // statements jumps to this point after calling return_xxx promise member.
62 CodeGenFunction::JumpDest FinalJD;
63
64 // Stores the llvm.coro.id emitted in the function so that we can supply it
65 // as the first argument to coro.begin, coro.alloc and coro.free intrinsics.
66 // Note: llvm.coro.id returns a token that cannot be directly expressed in a
67 // builtin.
68 llvm::CallInst *CoroId = nullptr;
69
70 // Stores the llvm.coro.begin emitted in the function so that we can replace
71 // all coro.frame intrinsics with direct SSA value of coro.begin that returns
72 // the address of the coroutine frame of the current coroutine.
73 llvm::CallInst *CoroBegin = nullptr;
74
75 // Stores the last emitted coro.free for the deallocate expressions, we use it
76 // to wrap dealloc code with if(auto mem = coro.free) dealloc(mem).
77 llvm::CallInst *LastCoroFree = nullptr;
78
79 // If coro.id came from the builtin, remember the expression to give better
80 // diagnostic. If CoroIdExpr is nullptr, the coro.id was created by
81 // EmitCoroutineBody.
82 CallExpr const *CoroIdExpr = nullptr;
83};
84
85// Defining these here allows to keep CGCoroData private to this file.
86clang::CodeGen::CodeGenFunction::CGCoroInfo::CGCoroInfo() {}
87CodeGenFunction::CGCoroInfo::~CGCoroInfo() {}
88
89static void createCoroData(CodeGenFunction &CGF,
90 CodeGenFunction::CGCoroInfo &CurCoro,
91 llvm::CallInst *CoroId,
92 CallExpr const *CoroIdExpr = nullptr) {
93 if (CurCoro.Data) {
3
Calling 'unique_ptr::operator bool'
7
Returning from 'unique_ptr::operator bool'
8
Taking true branch
94 if (CurCoro.Data->CoroIdExpr)
9
Assuming field 'CoroIdExpr' is non-null
10
Taking true branch
95 CGF.CGM.Error(CoroIdExpr->getBeginLoc(),
11
Called C++ object pointer is null
96 "only one __builtin_coro_id can be used in a function");
97 else if (CoroIdExpr)
98 CGF.CGM.Error(CoroIdExpr->getBeginLoc(),
99 "__builtin_coro_id shall not be used in a C++ coroutine");
100 else
101 llvm_unreachable("EmitCoroutineBodyStatement called twice?")::llvm::llvm_unreachable_internal("EmitCoroutineBodyStatement called twice?"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGCoroutine.cpp"
, 101)
;
102
103 return;
104 }
105
106 CurCoro.Data = std::unique_ptr<CGCoroData>(new CGCoroData);
107 CurCoro.Data->CoroId = CoroId;
108 CurCoro.Data->CoroIdExpr = CoroIdExpr;
109}
110
111// Synthesize a pretty name for a suspend point.
112static SmallString<32> buildSuspendPrefixStr(CGCoroData &Coro, AwaitKind Kind) {
113 unsigned No = 0;
114 switch (Kind) {
115 case AwaitKind::Init:
116 case AwaitKind::Final:
117 break;
118 case AwaitKind::Normal:
119 No = ++Coro.AwaitNum;
120 break;
121 case AwaitKind::Yield:
122 No = ++Coro.YieldNum;
123 break;
124 }
125 SmallString<32> Prefix(AwaitKindStr[static_cast<unsigned>(Kind)]);
126 if (No > 1) {
127 Twine(No).toVector(Prefix);
128 }
129 return Prefix;
130}
131
132static bool memberCallExpressionCanThrow(const Expr *E) {
133 if (const auto *CE = dyn_cast<CXXMemberCallExpr>(E))
134 if (const auto *Proto =
135 CE->getMethodDecl()->getType()->getAs<FunctionProtoType>())
136 if (isNoexceptExceptionSpec(Proto->getExceptionSpecType()) &&
137 Proto->canThrow() == CT_Cannot)
138 return false;
139 return true;
140}
141
142// Emit suspend expression which roughly looks like:
143//
144// auto && x = CommonExpr();
145// if (!x.await_ready()) {
146// llvm_coro_save();
147// x.await_suspend(...); (*)
148// llvm_coro_suspend(); (**)
149// }
150// x.await_resume();
151//
152// where the result of the entire expression is the result of x.await_resume()
153//
154// (*) If x.await_suspend return type is bool, it allows to veto a suspend:
155// if (x.await_suspend(...))
156// llvm_coro_suspend();
157//
158// (**) llvm_coro_suspend() encodes three possible continuations as
159// a switch instruction:
160//
161// %where-to = call i8 @llvm.coro.suspend(...)
162// switch i8 %where-to, label %coro.ret [ ; jump to epilogue to suspend
163// i8 0, label %yield.ready ; go here when resumed
164// i8 1, label %yield.cleanup ; go here when destroyed
165// ]
166//
167// See llvm's docs/Coroutines.rst for more details.
168//
169namespace {
170 struct LValueOrRValue {
171 LValue LV;
172 RValue RV;
173 };
174}
175static LValueOrRValue emitSuspendExpression(CodeGenFunction &CGF, CGCoroData &Coro,
176 CoroutineSuspendExpr const &S,
177 AwaitKind Kind, AggValueSlot aggSlot,
178 bool ignoreResult, bool forLValue) {
179 auto *E = S.getCommonExpr();
180
181 auto Binder =
182 CodeGenFunction::OpaqueValueMappingData::bind(CGF, S.getOpaqueValue(), E);
183 auto UnbindOnExit = llvm::make_scope_exit([&] { Binder.unbind(CGF); });
184
185 auto Prefix = buildSuspendPrefixStr(Coro, Kind);
186 BasicBlock *ReadyBlock = CGF.createBasicBlock(Prefix + Twine(".ready"));
187 BasicBlock *SuspendBlock = CGF.createBasicBlock(Prefix + Twine(".suspend"));
188 BasicBlock *CleanupBlock = CGF.createBasicBlock(Prefix + Twine(".cleanup"));
189
190 // If expression is ready, no need to suspend.
191 CGF.EmitBranchOnBoolExpr(S.getReadyExpr(), ReadyBlock, SuspendBlock, 0);
192
193 // Otherwise, emit suspend logic.
194 CGF.EmitBlock(SuspendBlock);
195
196 auto &Builder = CGF.Builder;
197 llvm::Function *CoroSave = CGF.CGM.getIntrinsic(llvm::Intrinsic::coro_save);
198 auto *NullPtr = llvm::ConstantPointerNull::get(CGF.CGM.Int8PtrTy);
199 auto *SaveCall = Builder.CreateCall(CoroSave, {NullPtr});
200
201 auto *SuspendRet = CGF.EmitScalarExpr(S.getSuspendExpr());
202 if (SuspendRet != nullptr && SuspendRet->getType()->isIntegerTy(1)) {
203 // Veto suspension if requested by bool returning await_suspend.
204 BasicBlock *RealSuspendBlock =
205 CGF.createBasicBlock(Prefix + Twine(".suspend.bool"));
206 CGF.Builder.CreateCondBr(SuspendRet, RealSuspendBlock, ReadyBlock);
207 CGF.EmitBlock(RealSuspendBlock);
208 }
209
210 // Emit the suspend point.
211 const bool IsFinalSuspend = (Kind == AwaitKind::Final);
212 llvm::Function *CoroSuspend =
213 CGF.CGM.getIntrinsic(llvm::Intrinsic::coro_suspend);
214 auto *SuspendResult = Builder.CreateCall(
215 CoroSuspend, {SaveCall, Builder.getInt1(IsFinalSuspend)});
216
217 // Create a switch capturing three possible continuations.
218 auto *Switch = Builder.CreateSwitch(SuspendResult, Coro.SuspendBB, 2);
219 Switch->addCase(Builder.getInt8(0), ReadyBlock);
220 Switch->addCase(Builder.getInt8(1), CleanupBlock);
221
222 // Emit cleanup for this suspend point.
223 CGF.EmitBlock(CleanupBlock);
224 CGF.EmitBranchThroughCleanup(Coro.CleanupJD);
225
226 // Emit await_resume expression.
227 CGF.EmitBlock(ReadyBlock);
228
229 // Exception handling requires additional IR. If the 'await_resume' function
230 // is marked as 'noexcept', we avoid generating this additional IR.
231 CXXTryStmt *TryStmt = nullptr;
232 if (Coro.ExceptionHandler && Kind == AwaitKind::Init &&
233 memberCallExpressionCanThrow(S.getResumeExpr())) {
234 Coro.ResumeEHVar =
235 CGF.CreateTempAlloca(Builder.getInt1Ty(), Prefix + Twine("resume.eh"));
236 Builder.CreateFlagStore(true, Coro.ResumeEHVar);
237
238 auto Loc = S.getResumeExpr()->getExprLoc();
239 auto *Catch = new (CGF.getContext())
240 CXXCatchStmt(Loc, /*exDecl=*/nullptr, Coro.ExceptionHandler);
241 auto *TryBody =
242 CompoundStmt::Create(CGF.getContext(), S.getResumeExpr(), Loc, Loc);
243 TryStmt = CXXTryStmt::Create(CGF.getContext(), Loc, TryBody, Catch);
244 CGF.EnterCXXTryStmt(*TryStmt);
245 }
246
247 LValueOrRValue Res;
248 if (forLValue)
249 Res.LV = CGF.EmitLValue(S.getResumeExpr());
250 else
251 Res.RV = CGF.EmitAnyExpr(S.getResumeExpr(), aggSlot, ignoreResult);
252
253 if (TryStmt) {
254 Builder.CreateFlagStore(false, Coro.ResumeEHVar);
255 CGF.ExitCXXTryStmt(*TryStmt);
256 }
257
258 return Res;
259}
260
261RValue CodeGenFunction::EmitCoawaitExpr(const CoawaitExpr &E,
262 AggValueSlot aggSlot,
263 bool ignoreResult) {
264 return emitSuspendExpression(*this, *CurCoro.Data, E,
265 CurCoro.Data->CurrentAwaitKind, aggSlot,
266 ignoreResult, /*forLValue*/false).RV;
267}
268RValue CodeGenFunction::EmitCoyieldExpr(const CoyieldExpr &E,
269 AggValueSlot aggSlot,
270 bool ignoreResult) {
271 return emitSuspendExpression(*this, *CurCoro.Data, E, AwaitKind::Yield,
272 aggSlot, ignoreResult, /*forLValue*/false).RV;
273}
274
275void CodeGenFunction::EmitCoreturnStmt(CoreturnStmt const &S) {
276 ++CurCoro.Data->CoreturnCount;
277 const Expr *RV = S.getOperand();
278 if (RV && RV->getType()->isVoidType()) {
279 // Make sure to evaluate the expression of a co_return with a void
280 // expression for side effects.
281 RunCleanupsScope cleanupScope(*this);
282 EmitIgnoredExpr(RV);
283 }
284 EmitStmt(S.getPromiseCall());
285 EmitBranchThroughCleanup(CurCoro.Data->FinalJD);
286}
287
288
289#ifndef NDEBUG
290static QualType getCoroutineSuspendExprReturnType(const ASTContext &Ctx,
291 const CoroutineSuspendExpr *E) {
292 const auto *RE = E->getResumeExpr();
293 // Is it possible for RE to be a CXXBindTemporaryExpr wrapping
294 // a MemberCallExpr?
295 assert(isa<CallExpr>(RE) && "unexpected suspend expression type")((isa<CallExpr>(RE) && "unexpected suspend expression type"
) ? static_cast<void> (0) : __assert_fail ("isa<CallExpr>(RE) && \"unexpected suspend expression type\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGCoroutine.cpp"
, 295, __PRETTY_FUNCTION__))
;
296 return cast<CallExpr>(RE)->getCallReturnType(Ctx);
297}
298#endif
299
300LValue
301CodeGenFunction::EmitCoawaitLValue(const CoawaitExpr *E) {
302 assert(getCoroutineSuspendExprReturnType(getContext(), E)->isReferenceType() &&((getCoroutineSuspendExprReturnType(getContext(), E)->isReferenceType
() && "Can't have a scalar return unless the return type is a "
"reference type!") ? static_cast<void> (0) : __assert_fail
("getCoroutineSuspendExprReturnType(getContext(), E)->isReferenceType() && \"Can't have a scalar return unless the return type is a \" \"reference type!\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGCoroutine.cpp"
, 304, __PRETTY_FUNCTION__))
303 "Can't have a scalar return unless the return type is a "((getCoroutineSuspendExprReturnType(getContext(), E)->isReferenceType
() && "Can't have a scalar return unless the return type is a "
"reference type!") ? static_cast<void> (0) : __assert_fail
("getCoroutineSuspendExprReturnType(getContext(), E)->isReferenceType() && \"Can't have a scalar return unless the return type is a \" \"reference type!\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGCoroutine.cpp"
, 304, __PRETTY_FUNCTION__))
304 "reference type!")((getCoroutineSuspendExprReturnType(getContext(), E)->isReferenceType
() && "Can't have a scalar return unless the return type is a "
"reference type!") ? static_cast<void> (0) : __assert_fail
("getCoroutineSuspendExprReturnType(getContext(), E)->isReferenceType() && \"Can't have a scalar return unless the return type is a \" \"reference type!\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGCoroutine.cpp"
, 304, __PRETTY_FUNCTION__))
;
305 return emitSuspendExpression(*this, *CurCoro.Data, *E,
306 CurCoro.Data->CurrentAwaitKind, AggValueSlot::ignored(),
307 /*ignoreResult*/false, /*forLValue*/true).LV;
308}
309
310LValue
311CodeGenFunction::EmitCoyieldLValue(const CoyieldExpr *E) {
312 assert(getCoroutineSuspendExprReturnType(getContext(), E)->isReferenceType() &&((getCoroutineSuspendExprReturnType(getContext(), E)->isReferenceType
() && "Can't have a scalar return unless the return type is a "
"reference type!") ? static_cast<void> (0) : __assert_fail
("getCoroutineSuspendExprReturnType(getContext(), E)->isReferenceType() && \"Can't have a scalar return unless the return type is a \" \"reference type!\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGCoroutine.cpp"
, 314, __PRETTY_FUNCTION__))
313 "Can't have a scalar return unless the return type is a "((getCoroutineSuspendExprReturnType(getContext(), E)->isReferenceType
() && "Can't have a scalar return unless the return type is a "
"reference type!") ? static_cast<void> (0) : __assert_fail
("getCoroutineSuspendExprReturnType(getContext(), E)->isReferenceType() && \"Can't have a scalar return unless the return type is a \" \"reference type!\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGCoroutine.cpp"
, 314, __PRETTY_FUNCTION__))
314 "reference type!")((getCoroutineSuspendExprReturnType(getContext(), E)->isReferenceType
() && "Can't have a scalar return unless the return type is a "
"reference type!") ? static_cast<void> (0) : __assert_fail
("getCoroutineSuspendExprReturnType(getContext(), E)->isReferenceType() && \"Can't have a scalar return unless the return type is a \" \"reference type!\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGCoroutine.cpp"
, 314, __PRETTY_FUNCTION__))
;
315 return emitSuspendExpression(*this, *CurCoro.Data, *E,
316 AwaitKind::Yield, AggValueSlot::ignored(),
317 /*ignoreResult*/false, /*forLValue*/true).LV;
318}
319
320// Hunts for the parameter reference in the parameter copy/move declaration.
321namespace {
322struct GetParamRef : public StmtVisitor<GetParamRef> {
323public:
324 DeclRefExpr *Expr = nullptr;
325 GetParamRef() {}
326 void VisitDeclRefExpr(DeclRefExpr *E) {
327 assert(Expr == nullptr && "multilple declref in param move")((Expr == nullptr && "multilple declref in param move"
) ? static_cast<void> (0) : __assert_fail ("Expr == nullptr && \"multilple declref in param move\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGCoroutine.cpp"
, 327, __PRETTY_FUNCTION__))
;
328 Expr = E;
329 }
330 void VisitStmt(Stmt *S) {
331 for (auto *C : S->children()) {
332 if (C)
333 Visit(C);
334 }
335 }
336};
337}
338
339// This class replaces references to parameters to their copies by changing
340// the addresses in CGF.LocalDeclMap and restoring back the original values in
341// its destructor.
342
343namespace {
344 struct ParamReferenceReplacerRAII {
345 CodeGenFunction::DeclMapTy SavedLocals;
346 CodeGenFunction::DeclMapTy& LocalDeclMap;
347
348 ParamReferenceReplacerRAII(CodeGenFunction::DeclMapTy &LocalDeclMap)
349 : LocalDeclMap(LocalDeclMap) {}
350
351 void addCopy(DeclStmt const *PM) {
352 // Figure out what param it refers to.
353
354 assert(PM->isSingleDecl())((PM->isSingleDecl()) ? static_cast<void> (0) : __assert_fail
("PM->isSingleDecl()", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGCoroutine.cpp"
, 354, __PRETTY_FUNCTION__))
;
355 VarDecl const*VD = static_cast<VarDecl const*>(PM->getSingleDecl());
356 Expr const *InitExpr = VD->getInit();
357 GetParamRef Visitor;
358 Visitor.Visit(const_cast<Expr*>(InitExpr));
359 assert(Visitor.Expr)((Visitor.Expr) ? static_cast<void> (0) : __assert_fail
("Visitor.Expr", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGCoroutine.cpp"
, 359, __PRETTY_FUNCTION__))
;
360 DeclRefExpr *DREOrig = Visitor.Expr;
361 auto *PD = DREOrig->getDecl();
362
363 auto it = LocalDeclMap.find(PD);
364 assert(it != LocalDeclMap.end() && "parameter is not found")((it != LocalDeclMap.end() && "parameter is not found"
) ? static_cast<void> (0) : __assert_fail ("it != LocalDeclMap.end() && \"parameter is not found\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGCoroutine.cpp"
, 364, __PRETTY_FUNCTION__))
;
365 SavedLocals.insert({ PD, it->second });
366
367 auto copyIt = LocalDeclMap.find(VD);
368 assert(copyIt != LocalDeclMap.end() && "parameter copy is not found")((copyIt != LocalDeclMap.end() && "parameter copy is not found"
) ? static_cast<void> (0) : __assert_fail ("copyIt != LocalDeclMap.end() && \"parameter copy is not found\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGCoroutine.cpp"
, 368, __PRETTY_FUNCTION__))
;
369 it->second = copyIt->getSecond();
370 }
371
372 ~ParamReferenceReplacerRAII() {
373 for (auto&& SavedLocal : SavedLocals) {
374 LocalDeclMap.insert({SavedLocal.first, SavedLocal.second});
375 }
376 }
377 };
378}
379
380// For WinEH exception representation backend needs to know what funclet coro.end
381// belongs to. That information is passed in a funclet bundle.
382static SmallVector<llvm::OperandBundleDef, 1>
383getBundlesForCoroEnd(CodeGenFunction &CGF) {
384 SmallVector<llvm::OperandBundleDef, 1> BundleList;
385
386 if (llvm::Instruction *EHPad = CGF.CurrentFuncletPad)
387 BundleList.emplace_back("funclet", EHPad);
388
389 return BundleList;
390}
391
392namespace {
393// We will insert coro.end to cut any of the destructors for objects that
394// do not need to be destroyed once the coroutine is resumed.
395// See llvm/docs/Coroutines.rst for more details about coro.end.
396struct CallCoroEnd final : public EHScopeStack::Cleanup {
397 void Emit(CodeGenFunction &CGF, Flags flags) override {
398 auto &CGM = CGF.CGM;
399 auto *NullPtr = llvm::ConstantPointerNull::get(CGF.Int8PtrTy);
400 llvm::Function *CoroEndFn = CGM.getIntrinsic(llvm::Intrinsic::coro_end);
401 // See if we have a funclet bundle to associate coro.end with. (WinEH)
402 auto Bundles = getBundlesForCoroEnd(CGF);
403 auto *CoroEnd = CGF.Builder.CreateCall(
404 CoroEndFn, {NullPtr, CGF.Builder.getTrue()}, Bundles);
405 if (Bundles.empty()) {
406 // Otherwise, (landingpad model), create a conditional branch that leads
407 // either to a cleanup block or a block with EH resume instruction.
408 auto *ResumeBB = CGF.getEHResumeBlock(/*isCleanup=*/true);
409 auto *CleanupContBB = CGF.createBasicBlock("cleanup.cont");
410 CGF.Builder.CreateCondBr(CoroEnd, ResumeBB, CleanupContBB);
411 CGF.EmitBlock(CleanupContBB);
412 }
413 }
414};
415}
416
417namespace {
418// Make sure to call coro.delete on scope exit.
419struct CallCoroDelete final : public EHScopeStack::Cleanup {
420 Stmt *Deallocate;
421
422 // Emit "if (coro.free(CoroId, CoroBegin)) Deallocate;"
423
424 // Note: That deallocation will be emitted twice: once for a normal exit and
425 // once for exceptional exit. This usage is safe because Deallocate does not
426 // contain any declarations. The SubStmtBuilder::makeNewAndDeleteExpr()
427 // builds a single call to a deallocation function which is safe to emit
428 // multiple times.
429 void Emit(CodeGenFunction &CGF, Flags) override {
430 // Remember the current point, as we are going to emit deallocation code
431 // first to get to coro.free instruction that is an argument to a delete
432 // call.
433 BasicBlock *SaveInsertBlock = CGF.Builder.GetInsertBlock();
434
435 auto *FreeBB = CGF.createBasicBlock("coro.free");
436 CGF.EmitBlock(FreeBB);
437 CGF.EmitStmt(Deallocate);
438
439 auto *AfterFreeBB = CGF.createBasicBlock("after.coro.free");
440 CGF.EmitBlock(AfterFreeBB);
441
442 // We should have captured coro.free from the emission of deallocate.
443 auto *CoroFree = CGF.CurCoro.Data->LastCoroFree;
444 if (!CoroFree) {
445 CGF.CGM.Error(Deallocate->getBeginLoc(),
446 "Deallocation expressoin does not refer to coro.free");
447 return;
448 }
449
450 // Get back to the block we were originally and move coro.free there.
451 auto *InsertPt = SaveInsertBlock->getTerminator();
452 CoroFree->moveBefore(InsertPt);
453 CGF.Builder.SetInsertPoint(InsertPt);
454
455 // Add if (auto *mem = coro.free) Deallocate;
456 auto *NullPtr = llvm::ConstantPointerNull::get(CGF.Int8PtrTy);
457 auto *Cond = CGF.Builder.CreateICmpNE(CoroFree, NullPtr);
458 CGF.Builder.CreateCondBr(Cond, FreeBB, AfterFreeBB);
459
460 // No longer need old terminator.
461 InsertPt->eraseFromParent();
462 CGF.Builder.SetInsertPoint(AfterFreeBB);
463 }
464 explicit CallCoroDelete(Stmt *DeallocStmt) : Deallocate(DeallocStmt) {}
465};
466}
467
468namespace {
469struct GetReturnObjectManager {
470 CodeGenFunction &CGF;
471 CGBuilderTy &Builder;
472 const CoroutineBodyStmt &S;
473
474 Address GroActiveFlag;
475 CodeGenFunction::AutoVarEmission GroEmission;
476
477 GetReturnObjectManager(CodeGenFunction &CGF, const CoroutineBodyStmt &S)
478 : CGF(CGF), Builder(CGF.Builder), S(S), GroActiveFlag(Address::invalid()),
479 GroEmission(CodeGenFunction::AutoVarEmission::invalid()) {}
480
481 // The gro variable has to outlive coroutine frame and coroutine promise, but,
482 // it can only be initialized after coroutine promise was created, thus, we
483 // split its emission in two parts. EmitGroAlloca emits an alloca and sets up
484 // cleanups. Later when coroutine promise is available we initialize the gro
485 // and sets the flag that the cleanup is now active.
486
487 void EmitGroAlloca() {
488 auto *GroDeclStmt = dyn_cast<DeclStmt>(S.getResultDecl());
489 if (!GroDeclStmt) {
490 // If get_return_object returns void, no need to do an alloca.
491 return;
492 }
493
494 auto *GroVarDecl = cast<VarDecl>(GroDeclStmt->getSingleDecl());
495
496 // Set GRO flag that it is not initialized yet
497 GroActiveFlag =
498 CGF.CreateTempAlloca(Builder.getInt1Ty(), CharUnits::One(), "gro.active");
499 Builder.CreateStore(Builder.getFalse(), GroActiveFlag);
500
501 GroEmission = CGF.EmitAutoVarAlloca(*GroVarDecl);
502
503 // Remember the top of EHStack before emitting the cleanup.
504 auto old_top = CGF.EHStack.stable_begin();
505 CGF.EmitAutoVarCleanups(GroEmission);
506 auto top = CGF.EHStack.stable_begin();
507
508 // Make the cleanup conditional on gro.active
509 for (auto b = CGF.EHStack.find(top), e = CGF.EHStack.find(old_top);
510 b != e; b++) {
511 if (auto *Cleanup = dyn_cast<EHCleanupScope>(&*b)) {
512 assert(!Cleanup->hasActiveFlag() && "cleanup already has active flag?")((!Cleanup->hasActiveFlag() && "cleanup already has active flag?"
) ? static_cast<void> (0) : __assert_fail ("!Cleanup->hasActiveFlag() && \"cleanup already has active flag?\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/clang/lib/CodeGen/CGCoroutine.cpp"
, 512, __PRETTY_FUNCTION__))
;
513 Cleanup->setActiveFlag(GroActiveFlag);
514 Cleanup->setTestFlagInEHCleanup();
515 Cleanup->setTestFlagInNormalCleanup();
516 }
517 }
518 }
519
520 void EmitGroInit() {
521 if (!GroActiveFlag.isValid()) {
522 // No Gro variable was allocated. Simply emit the call to
523 // get_return_object.
524 CGF.EmitStmt(S.getResultDecl());
525 return;
526 }
527
528 CGF.EmitAutoVarInit(GroEmission);
529 Builder.CreateStore(Builder.getTrue(), GroActiveFlag);
530 }
531};
532}
533
534static void emitBodyAndFallthrough(CodeGenFunction &CGF,
535 const CoroutineBodyStmt &S, Stmt *Body) {
536 CGF.EmitStmt(Body);
537 const bool CanFallthrough = CGF.Builder.GetInsertBlock();
538 if (CanFallthrough)
539 if (Stmt *OnFallthrough = S.getFallthroughHandler())
540 CGF.EmitStmt(OnFallthrough);
541}
542
543void CodeGenFunction::EmitCoroutineBody(const CoroutineBodyStmt &S) {
544 auto *NullPtr = llvm::ConstantPointerNull::get(Builder.getInt8PtrTy());
545 auto &TI = CGM.getContext().getTargetInfo();
546 unsigned NewAlign = TI.getNewAlign() / TI.getCharWidth();
547
548 auto *EntryBB = Builder.GetInsertBlock();
549 auto *AllocBB = createBasicBlock("coro.alloc");
550 auto *InitBB = createBasicBlock("coro.init");
551 auto *FinalBB = createBasicBlock("coro.final");
552 auto *RetBB = createBasicBlock("coro.ret");
553
554 auto *CoroId = Builder.CreateCall(
555 CGM.getIntrinsic(llvm::Intrinsic::coro_id),
556 {Builder.getInt32(NewAlign), NullPtr, NullPtr, NullPtr});
557 createCoroData(*this, CurCoro, CoroId);
1
Passing null pointer value via 4th parameter 'CoroIdExpr'
2
Calling 'createCoroData'
558 CurCoro.Data->SuspendBB = RetBB;
559
560 // Backend is allowed to elide memory allocations, to help it, emit
561 // auto mem = coro.alloc() ? 0 : ... allocation code ...;
562 auto *CoroAlloc = Builder.CreateCall(
563 CGM.getIntrinsic(llvm::Intrinsic::coro_alloc), {CoroId});
564
565 Builder.CreateCondBr(CoroAlloc, AllocBB, InitBB);
566
567 EmitBlock(AllocBB);
568 auto *AllocateCall = EmitScalarExpr(S.getAllocate());
569 auto *AllocOrInvokeContBB = Builder.GetInsertBlock();
570
571 // Handle allocation failure if 'ReturnStmtOnAllocFailure' was provided.
572 if (auto *RetOnAllocFailure = S.getReturnStmtOnAllocFailure()) {
573 auto *RetOnFailureBB = createBasicBlock("coro.ret.on.failure");
574
575 // See if allocation was successful.
576 auto *NullPtr = llvm::ConstantPointerNull::get(Int8PtrTy);
577 auto *Cond = Builder.CreateICmpNE(AllocateCall, NullPtr);
578 Builder.CreateCondBr(Cond, InitBB, RetOnFailureBB);
579
580 // If not, return OnAllocFailure object.
581 EmitBlock(RetOnFailureBB);
582 EmitStmt(RetOnAllocFailure);
583 }
584 else {
585 Builder.CreateBr(InitBB);
586 }
587
588 EmitBlock(InitBB);
589
590 // Pass the result of the allocation to coro.begin.
591 auto *Phi = Builder.CreatePHI(VoidPtrTy, 2);
592 Phi->addIncoming(NullPtr, EntryBB);
593 Phi->addIncoming(AllocateCall, AllocOrInvokeContBB);
594 auto *CoroBegin = Builder.CreateCall(
595 CGM.getIntrinsic(llvm::Intrinsic::coro_begin), {CoroId, Phi});
596 CurCoro.Data->CoroBegin = CoroBegin;
597
598 GetReturnObjectManager GroManager(*this, S);
599 GroManager.EmitGroAlloca();
600
601 CurCoro.Data->CleanupJD = getJumpDestInCurrentScope(RetBB);
602 {
603 ParamReferenceReplacerRAII ParamReplacer(LocalDeclMap);
604 CodeGenFunction::RunCleanupsScope ResumeScope(*this);
605 EHStack.pushCleanup<CallCoroDelete>(NormalAndEHCleanup, S.getDeallocate());
606
607 // Create parameter copies. We do it before creating a promise, since an
608 // evolution of coroutine TS may allow promise constructor to observe
609 // parameter copies.
610 for (auto *PM : S.getParamMoves()) {
611 EmitStmt(PM);
612 ParamReplacer.addCopy(cast<DeclStmt>(PM));
613 // TODO: if(CoroParam(...)) need to surround ctor and dtor
614 // for the copy, so that llvm can elide it if the copy is
615 // not needed.
616 }
617
618 EmitStmt(S.getPromiseDeclStmt());
619
620 Address PromiseAddr = GetAddrOfLocalVar(S.getPromiseDecl());
621 auto *PromiseAddrVoidPtr =
622 new llvm::BitCastInst(PromiseAddr.getPointer(), VoidPtrTy, "", CoroId);
623 // Update CoroId to refer to the promise. We could not do it earlier because
624 // promise local variable was not emitted yet.
625 CoroId->setArgOperand(1, PromiseAddrVoidPtr);
626
627 // Now we have the promise, initialize the GRO
628 GroManager.EmitGroInit();
629
630 EHStack.pushCleanup<CallCoroEnd>(EHCleanup);
631
632 CurCoro.Data->CurrentAwaitKind = AwaitKind::Init;
633 CurCoro.Data->ExceptionHandler = S.getExceptionHandler();
634 EmitStmt(S.getInitSuspendStmt());
635 CurCoro.Data->FinalJD = getJumpDestInCurrentScope(FinalBB);
636
637 CurCoro.Data->CurrentAwaitKind = AwaitKind::Normal;
638
639 if (CurCoro.Data->ExceptionHandler) {
640 // If we generated IR to record whether an exception was thrown from
641 // 'await_resume', then use that IR to determine whether the coroutine
642 // body should be skipped.
643 // If we didn't generate the IR (perhaps because 'await_resume' was marked
644 // as 'noexcept'), then we skip this check.
645 BasicBlock *ContBB = nullptr;
646 if (CurCoro.Data->ResumeEHVar) {
647 BasicBlock *BodyBB = createBasicBlock("coro.resumed.body");
648 ContBB = createBasicBlock("coro.resumed.cont");
649 Value *SkipBody = Builder.CreateFlagLoad(CurCoro.Data->ResumeEHVar,
650 "coro.resumed.eh");
651 Builder.CreateCondBr(SkipBody, ContBB, BodyBB);
652 EmitBlock(BodyBB);
653 }
654
655 auto Loc = S.getBeginLoc();
656 CXXCatchStmt Catch(Loc, /*exDecl=*/nullptr,
657 CurCoro.Data->ExceptionHandler);
658 auto *TryStmt =
659 CXXTryStmt::Create(getContext(), Loc, S.getBody(), &Catch);
660
661 EnterCXXTryStmt(*TryStmt);
662 emitBodyAndFallthrough(*this, S, TryStmt->getTryBlock());
663 ExitCXXTryStmt(*TryStmt);
664
665 if (ContBB)
666 EmitBlock(ContBB);
667 }
668 else {
669 emitBodyAndFallthrough(*this, S, S.getBody());
670 }
671
672 // See if we need to generate final suspend.
673 const bool CanFallthrough = Builder.GetInsertBlock();
674 const bool HasCoreturns = CurCoro.Data->CoreturnCount > 0;
675 if (CanFallthrough || HasCoreturns) {
676 EmitBlock(FinalBB);
677 CurCoro.Data->CurrentAwaitKind = AwaitKind::Final;
678 EmitStmt(S.getFinalSuspendStmt());
679 } else {
680 // We don't need FinalBB. Emit it to make sure the block is deleted.
681 EmitBlock(FinalBB, /*IsFinished=*/true);
682 }
683 }
684
685 EmitBlock(RetBB);
686 // Emit coro.end before getReturnStmt (and parameter destructors), since
687 // resume and destroy parts of the coroutine should not include them.
688 llvm::Function *CoroEnd = CGM.getIntrinsic(llvm::Intrinsic::coro_end);
689 Builder.CreateCall(CoroEnd, {NullPtr, Builder.getFalse()});
690
691 if (Stmt *Ret = S.getReturnStmt())
692 EmitStmt(Ret);
693}
694
695// Emit coroutine intrinsic and patch up arguments of the token type.
696RValue CodeGenFunction::EmitCoroutineIntrinsic(const CallExpr *E,
697 unsigned int IID) {
698 SmallVector<llvm::Value *, 8> Args;
699 switch (IID) {
700 default:
701 break;
702 // The coro.frame builtin is replaced with an SSA value of the coro.begin
703 // intrinsic.
704 case llvm::Intrinsic::coro_frame: {
705 if (CurCoro.Data && CurCoro.Data->CoroBegin) {
706 return RValue::get(CurCoro.Data->CoroBegin);
707 }
708 CGM.Error(E->getBeginLoc(), "this builtin expect that __builtin_coro_begin "
709 "has been used earlier in this function");
710 auto NullPtr = llvm::ConstantPointerNull::get(Builder.getInt8PtrTy());
711 return RValue::get(NullPtr);
712 }
713 // The following three intrinsics take a token parameter referring to a token
714 // returned by earlier call to @llvm.coro.id. Since we cannot represent it in
715 // builtins, we patch it up here.
716 case llvm::Intrinsic::coro_alloc:
717 case llvm::Intrinsic::coro_begin:
718 case llvm::Intrinsic::coro_free: {
719 if (CurCoro.Data && CurCoro.Data->CoroId) {
720 Args.push_back(CurCoro.Data->CoroId);
721 break;
722 }
723 CGM.Error(E->getBeginLoc(), "this builtin expect that __builtin_coro_id has"
724 " been used earlier in this function");
725 // Fallthrough to the next case to add TokenNone as the first argument.
726 LLVM_FALLTHROUGH[[gnu::fallthrough]];
727 }
728 // @llvm.coro.suspend takes a token parameter. Add token 'none' as the first
729 // argument.
730 case llvm::Intrinsic::coro_suspend:
731 Args.push_back(llvm::ConstantTokenNone::get(getLLVMContext()));
732 break;
733 }
734 for (const Expr *Arg : E->arguments())
735 Args.push_back(EmitScalarExpr(Arg));
736
737 llvm::Function *F = CGM.getIntrinsic(IID);
738 llvm::CallInst *Call = Builder.CreateCall(F, Args);
739
740 // Note: The following code is to enable to emit coro.id and coro.begin by
741 // hand to experiment with coroutines in C.
742 // If we see @llvm.coro.id remember it in the CoroData. We will update
743 // coro.alloc, coro.begin and coro.free intrinsics to refer to it.
744 if (IID == llvm::Intrinsic::coro_id) {
745 createCoroData(*this, CurCoro, Call, E);
746 }
747 else if (IID == llvm::Intrinsic::coro_begin) {
748 if (CurCoro.Data)
749 CurCoro.Data->CoroBegin = Call;
750 }
751 else if (IID == llvm::Intrinsic::coro_free) {
752 // Remember the last coro_free as we need it to build the conditional
753 // deletion of the coroutine frame.
754 if (CurCoro.Data)
755 CurCoro.Data->LastCoroFree = Call;
756 }
757 return RValue::get(Call);
758}

/usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/bits/unique_ptr.h

1// unique_ptr implementation -*- C++ -*-
2
3// Copyright (C) 2008-2016 Free Software Foundation, Inc.
4//
5// This file is part of the GNU ISO C++ Library. This library is free
6// software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the
8// Free Software Foundation; either version 3, or (at your option)
9// any later version.
10
11// This library is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14// GNU General Public License for more details.
15
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
19
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23// <http://www.gnu.org/licenses/>.
24
25/** @file bits/unique_ptr.h
26 * This is an internal header file, included by other library headers.
27 * Do not attempt to use it directly. @headername{memory}
28 */
29
30#ifndef _UNIQUE_PTR_H1
31#define _UNIQUE_PTR_H1 1
32
33#include <bits/c++config.h>
34#include <debug/assertions.h>
35#include <type_traits>
36#include <utility>
37#include <tuple>
38
39namespace std _GLIBCXX_VISIBILITY(default)__attribute__ ((__visibility__ ("default")))
40{
41_GLIBCXX_BEGIN_NAMESPACE_VERSION
42
43 /**
44 * @addtogroup pointer_abstractions
45 * @{
46 */
47
48#if _GLIBCXX_USE_DEPRECATED1
49 template<typename> class auto_ptr;
50#endif
51
52 /// Primary template of default_delete, used by unique_ptr
53 template<typename _Tp>
54 struct default_delete
55 {
56 /// Default constructor
57 constexpr default_delete() noexcept = default;
58
59 /** @brief Converting constructor.
60 *
61 * Allows conversion from a deleter for arrays of another type, @p _Up,
62 * only if @p _Up* is convertible to @p _Tp*.
63 */
64 template<typename _Up, typename = typename
65 enable_if<is_convertible<_Up*, _Tp*>::value>::type>
66 default_delete(const default_delete<_Up>&) noexcept { }
67
68 /// Calls @c delete @p __ptr
69 void
70 operator()(_Tp* __ptr) const
71 {
72 static_assert(!is_void<_Tp>::value,
73 "can't delete pointer to incomplete type");
74 static_assert(sizeof(_Tp)>0,
75 "can't delete pointer to incomplete type");
76 delete __ptr;
77 }
78 };
79
80 // _GLIBCXX_RESOLVE_LIB_DEFECTS
81 // DR 740 - omit specialization for array objects with a compile time length
82 /// Specialization for arrays, default_delete.
83 template<typename _Tp>
84 struct default_delete<_Tp[]>
85 {
86 public:
87 /// Default constructor
88 constexpr default_delete() noexcept = default;
89
90 /** @brief Converting constructor.
91 *
92 * Allows conversion from a deleter for arrays of another type, such as
93 * a const-qualified version of @p _Tp.
94 *
95 * Conversions from types derived from @c _Tp are not allowed because
96 * it is unsafe to @c delete[] an array of derived types through a
97 * pointer to the base type.
98 */
99 template<typename _Up, typename = typename
100 enable_if<is_convertible<_Up(*)[], _Tp(*)[]>::value>::type>
101 default_delete(const default_delete<_Up[]>&) noexcept { }
102
103 /// Calls @c delete[] @p __ptr
104 template<typename _Up>
105 typename enable_if<is_convertible<_Up(*)[], _Tp(*)[]>::value>::type
106 operator()(_Up* __ptr) const
107 {
108 static_assert(sizeof(_Tp)>0,
109 "can't delete pointer to incomplete type");
110 delete [] __ptr;
111 }
112 };
113
114 /// 20.7.1.2 unique_ptr for single objects.
115 template <typename _Tp, typename _Dp = default_delete<_Tp> >
116 class unique_ptr
117 {
118 // use SFINAE to determine whether _Del::pointer exists
119 class _Pointer
120 {
121 template<typename _Up>
122 static typename _Up::pointer __test(typename _Up::pointer*);
123
124 template<typename _Up>
125 static _Tp* __test(...);
126
127 typedef typename remove_reference<_Dp>::type _Del;
128
129 public:
130 typedef decltype(__test<_Del>(0)) type;
131 };
132
133 typedef std::tuple<typename _Pointer::type, _Dp> __tuple_type;
134 __tuple_type _M_t;
135
136 public:
137 typedef typename _Pointer::type pointer;
138 typedef _Tp element_type;
139 typedef _Dp deleter_type;
140
141
142 // helper template for detecting a safe conversion from another
143 // unique_ptr
144 template<typename _Up, typename _Ep>
145 using __safe_conversion_up = __and_<
146 is_convertible<typename unique_ptr<_Up, _Ep>::pointer, pointer>,
147 __not_<is_array<_Up>>,
148 __or_<__and_<is_reference<deleter_type>,
149 is_same<deleter_type, _Ep>>,
150 __and_<__not_<is_reference<deleter_type>>,
151 is_convertible<_Ep, deleter_type>>
152 >
153 >;
154
155 // Constructors.
156
157 /// Default constructor, creates a unique_ptr that owns nothing.
158 constexpr unique_ptr() noexcept
159 : _M_t()
160 { static_assert(!is_pointer<deleter_type>::value,
161 "constructed with null function pointer deleter"); }
162
163 /** Takes ownership of a pointer.
164 *
165 * @param __p A pointer to an object of @c element_type
166 *
167 * The deleter will be value-initialized.
168 */
169 explicit
170 unique_ptr(pointer __p) noexcept
171 : _M_t()
172 {
173 std::get<0>(_M_t) = __p;
174 static_assert(!is_pointer<deleter_type>::value,
175 "constructed with null function pointer deleter");
176 }
177
178 /** Takes ownership of a pointer.
179 *
180 * @param __p A pointer to an object of @c element_type
181 * @param __d A reference to a deleter.
182 *
183 * The deleter will be initialized with @p __d
184 */
185 unique_ptr(pointer __p,
186 typename conditional<is_reference<deleter_type>::value,
187 deleter_type, const deleter_type&>::type __d) noexcept
188 : _M_t(__p, __d) { }
189
190 /** Takes ownership of a pointer.
191 *
192 * @param __p A pointer to an object of @c element_type
193 * @param __d An rvalue reference to a deleter.
194 *
195 * The deleter will be initialized with @p std::move(__d)
196 */
197 unique_ptr(pointer __p,
198 typename remove_reference<deleter_type>::type&& __d) noexcept
199 : _M_t(std::move(__p), std::move(__d))
200 { static_assert(!std::is_reference<deleter_type>::value,
201 "rvalue deleter bound to reference"); }
202
203 /// Creates a unique_ptr that owns nothing.
204 constexpr unique_ptr(nullptr_t) noexcept : unique_ptr() { }
205
206 // Move constructors.
207
208 /// Move constructor.
209 unique_ptr(unique_ptr&& __u) noexcept
210 : _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter())) { }
211
212 /** @brief Converting constructor from another type
213 *
214 * Requires that the pointer owned by @p __u is convertible to the
215 * type of pointer owned by this object, @p __u does not own an array,
216 * and @p __u has a compatible deleter type.
217 */
218 template<typename _Up, typename _Ep, typename = _Require<
219 __safe_conversion_up<_Up, _Ep>,
220 typename conditional<is_reference<_Dp>::value,
221 is_same<_Ep, _Dp>,
222 is_convertible<_Ep, _Dp>>::type>>
223 unique_ptr(unique_ptr<_Up, _Ep>&& __u) noexcept
224 : _M_t(__u.release(), std::forward<_Ep>(__u.get_deleter()))
225 { }
226
227#if _GLIBCXX_USE_DEPRECATED1
228 /// Converting constructor from @c auto_ptr
229 template<typename _Up, typename = _Require<
230 is_convertible<_Up*, _Tp*>, is_same<_Dp, default_delete<_Tp>>>>
231 unique_ptr(auto_ptr<_Up>&& __u) noexcept;
232#endif
233
234 /// Destructor, invokes the deleter if the stored pointer is not null.
235 ~unique_ptr() noexcept
236 {
237 auto& __ptr = std::get<0>(_M_t);
238 if (__ptr != nullptr)
239 get_deleter()(__ptr);
240 __ptr = pointer();
241 }
242
243 // Assignment.
244
245 /** @brief Move assignment operator.
246 *
247 * @param __u The object to transfer ownership from.
248 *
249 * Invokes the deleter first if this object owns a pointer.
250 */
251 unique_ptr&
252 operator=(unique_ptr&& __u) noexcept
253 {
254 reset(__u.release());
255 get_deleter() = std::forward<deleter_type>(__u.get_deleter());
256 return *this;
257 }
258
259 /** @brief Assignment from another type.
260 *
261 * @param __u The object to transfer ownership from, which owns a
262 * convertible pointer to a non-array object.
263 *
264 * Invokes the deleter first if this object owns a pointer.
265 */
266 template<typename _Up, typename _Ep>
267 typename enable_if< __and_<
268 __safe_conversion_up<_Up, _Ep>,
269 is_assignable<deleter_type&, _Ep&&>
270 >::value,
271 unique_ptr&>::type
272 operator=(unique_ptr<_Up, _Ep>&& __u) noexcept
273 {
274 reset(__u.release());
275 get_deleter() = std::forward<_Ep>(__u.get_deleter());
276 return *this;
277 }
278
279 /// Reset the %unique_ptr to empty, invoking the deleter if necessary.
280 unique_ptr&
281 operator=(nullptr_t) noexcept
282 {
283 reset();
284 return *this;
285 }
286
287 // Observers.
288
289 /// Dereference the stored pointer.
290 typename add_lvalue_reference<element_type>::type
291 operator*() const
292 {
293 __glibcxx_assert(get() != pointer());
294 return *get();
295 }
296
297 /// Return the stored pointer.
298 pointer
299 operator->() const noexcept
300 {
301 _GLIBCXX_DEBUG_PEDASSERT(get() != pointer());
302 return get();
303 }
304
305 /// Return the stored pointer.
306 pointer
307 get() const noexcept
308 { return std::get<0>(_M_t); }
309
310 /// Return a reference to the stored deleter.
311 deleter_type&
312 get_deleter() noexcept
313 { return std::get<1>(_M_t); }
314
315 /// Return a reference to the stored deleter.
316 const deleter_type&
317 get_deleter() const noexcept
318 { return std::get<1>(_M_t); }
319
320 /// Return @c true if the stored pointer is not null.
321 explicit operator bool() const noexcept
322 { return get() == pointer() ? false : true; }
4
Assuming the condition is false
5
'?' condition is false
6
Returning the value 1, which participates in a condition later
323
324 // Modifiers.
325
326 /// Release ownership of any stored pointer.
327 pointer
328 release() noexcept
329 {
330 pointer __p = get();
331 std::get<0>(_M_t) = pointer();
332 return __p;
333 }
334
335 /** @brief Replace the stored pointer.
336 *
337 * @param __p The new pointer to store.
338 *
339 * The deleter will be invoked if a pointer is already owned.
340 */
341 void
342 reset(pointer __p = pointer()) noexcept
343 {
344 using std::swap;
345 swap(std::get<0>(_M_t), __p);
346 if (__p != pointer())
347 get_deleter()(__p);
348 }
349
350 /// Exchange the pointer and deleter with another object.
351 void
352 swap(unique_ptr& __u) noexcept
353 {
354 using std::swap;
355 swap(_M_t, __u._M_t);
356 }
357
358 // Disable copy from lvalue.
359 unique_ptr(const unique_ptr&) = delete;
360 unique_ptr& operator=(const unique_ptr&) = delete;
361 };
362
363 /// 20.7.1.3 unique_ptr for array objects with a runtime length
364 // [unique.ptr.runtime]
365 // _GLIBCXX_RESOLVE_LIB_DEFECTS
366 // DR 740 - omit specialization for array objects with a compile time length
367 template<typename _Tp, typename _Dp>
368 class unique_ptr<_Tp[], _Dp>
369 {
370 // use SFINAE to determine whether _Del::pointer exists
371 class _Pointer
372 {
373 template<typename _Up>
374 static typename _Up::pointer __test(typename _Up::pointer*);
375
376 template<typename _Up>
377 static _Tp* __test(...);
378
379 typedef typename remove_reference<_Dp>::type _Del;
380
381 public:
382 typedef decltype(__test<_Del>(0)) type;
383 };
384
385 typedef std::tuple<typename _Pointer::type, _Dp> __tuple_type;
386 __tuple_type _M_t;
387
388 template<typename _Up>
389 using __remove_cv = typename remove_cv<_Up>::type;
390
391 // like is_base_of<_Tp, _Up> but false if unqualified types are the same
392 template<typename _Up>
393 using __is_derived_Tp
394 = __and_< is_base_of<_Tp, _Up>,
395 __not_<is_same<__remove_cv<_Tp>, __remove_cv<_Up>>> >;
396
397
398 public:
399 typedef typename _Pointer::type pointer;
400 typedef _Tp element_type;
401 typedef _Dp deleter_type;
402
403 // helper template for detecting a safe conversion from another
404 // unique_ptr
405 template<typename _Up, typename _Ep,
406 typename _Up_up = unique_ptr<_Up, _Ep>,
407 typename _Up_element_type = typename _Up_up::element_type>
408 using __safe_conversion_up = __and_<
409 is_array<_Up>,
410 is_same<pointer, element_type*>,
411 is_same<typename _Up_up::pointer, _Up_element_type*>,
412 is_convertible<_Up_element_type(*)[], element_type(*)[]>,
413 __or_<__and_<is_reference<deleter_type>, is_same<deleter_type, _Ep>>,
414 __and_<__not_<is_reference<deleter_type>>,
415 is_convertible<_Ep, deleter_type>>>
416 >;
417
418 // helper template for detecting a safe conversion from a raw pointer
419 template<typename _Up>
420 using __safe_conversion_raw = __and_<
421 __or_<__or_<is_same<_Up, pointer>,
422 is_same<_Up, nullptr_t>>,
423 __and_<is_pointer<_Up>,
424 is_same<pointer, element_type*>,
425 is_convertible<
426 typename remove_pointer<_Up>::type(*)[],
427 element_type(*)[]>
428 >
429 >
430 >;
431
432 // Constructors.
433
434 /// Default constructor, creates a unique_ptr that owns nothing.
435 constexpr unique_ptr() noexcept
436 : _M_t()
437 { static_assert(!std::is_pointer<deleter_type>::value,
438 "constructed with null function pointer deleter"); }
439
440 /** Takes ownership of a pointer.
441 *
442 * @param __p A pointer to an array of a type safely convertible
443 * to an array of @c element_type
444 *
445 * The deleter will be value-initialized.
446 */
447 template<typename _Up,
448 typename = typename enable_if<
449 __safe_conversion_raw<_Up>::value, bool>::type>
450 explicit
451 unique_ptr(_Up __p) noexcept
452 : _M_t(__p, deleter_type())
453 { static_assert(!is_pointer<deleter_type>::value,
454 "constructed with null function pointer deleter"); }
455
456 /** Takes ownership of a pointer.
457 *
458 * @param __p A pointer to an array of a type safely convertible
459 * to an array of @c element_type
460 * @param __d A reference to a deleter.
461 *
462 * The deleter will be initialized with @p __d
463 */
464 template<typename _Up,
465 typename = typename enable_if<
466 __safe_conversion_raw<_Up>::value, bool>::type>
467 unique_ptr(_Up __p,
468 typename conditional<is_reference<deleter_type>::value,
469 deleter_type, const deleter_type&>::type __d) noexcept
470 : _M_t(__p, __d) { }
471
472 /** Takes ownership of a pointer.
473 *
474 * @param __p A pointer to an array of a type safely convertible
475 * to an array of @c element_type
476 * @param __d A reference to a deleter.
477 *
478 * The deleter will be initialized with @p std::move(__d)
479 */
480 template<typename _Up,
481 typename = typename enable_if<
482 __safe_conversion_raw<_Up>::value, bool>::type>
483 unique_ptr(_Up __p, typename
484 remove_reference<deleter_type>::type&& __d) noexcept
485 : _M_t(std::move(__p), std::move(__d))
486 { static_assert(!is_reference<deleter_type>::value,
487 "rvalue deleter bound to reference"); }
488
489 /// Move constructor.
490 unique_ptr(unique_ptr&& __u) noexcept
491 : _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter())) { }
492
493 /// Creates a unique_ptr that owns nothing.
494 constexpr unique_ptr(nullptr_t) noexcept : unique_ptr() { }
495
496 template<typename _Up, typename _Ep,
497 typename = _Require<__safe_conversion_up<_Up, _Ep>>>
498 unique_ptr(unique_ptr<_Up, _Ep>&& __u) noexcept
499 : _M_t(__u.release(), std::forward<_Ep>(__u.get_deleter()))
500 { }
501
502 /// Destructor, invokes the deleter if the stored pointer is not null.
503 ~unique_ptr()
504 {
505 auto& __ptr = std::get<0>(_M_t);
506 if (__ptr != nullptr)
507 get_deleter()(__ptr);
508 __ptr = pointer();
509 }
510
511 // Assignment.
512
513 /** @brief Move assignment operator.
514 *
515 * @param __u The object to transfer ownership from.
516 *
517 * Invokes the deleter first if this object owns a pointer.
518 */
519 unique_ptr&
520 operator=(unique_ptr&& __u) noexcept
521 {
522 reset(__u.release());
523 get_deleter() = std::forward<deleter_type>(__u.get_deleter());
524 return *this;
525 }
526
527 /** @brief Assignment from another type.
528 *
529 * @param __u The object to transfer ownership from, which owns a
530 * convertible pointer to an array object.
531 *
532 * Invokes the deleter first if this object owns a pointer.
533 */
534 template<typename _Up, typename _Ep>
535 typename
536 enable_if<__and_<__safe_conversion_up<_Up, _Ep>,
537 is_assignable<deleter_type&, _Ep&&>
538 >::value,
539 unique_ptr&>::type
540 operator=(unique_ptr<_Up, _Ep>&& __u) noexcept
541 {
542 reset(__u.release());
543 get_deleter() = std::forward<_Ep>(__u.get_deleter());
544 return *this;
545 }
546
547 /// Reset the %unique_ptr to empty, invoking the deleter if necessary.
548 unique_ptr&
549 operator=(nullptr_t) noexcept
550 {
551 reset();
552 return *this;
553 }
554
555 // Observers.
556
557 /// Access an element of owned array.
558 typename std::add_lvalue_reference<element_type>::type
559 operator[](size_t __i) const
560 {
561 __glibcxx_assert(get() != pointer());
562 return get()[__i];
563 }
564
565 /// Return the stored pointer.
566 pointer
567 get() const noexcept
568 { return std::get<0>(_M_t); }
569
570 /// Return a reference to the stored deleter.
571 deleter_type&
572 get_deleter() noexcept
573 { return std::get<1>(_M_t); }
574
575 /// Return a reference to the stored deleter.
576 const deleter_type&
577 get_deleter() const noexcept
578 { return std::get<1>(_M_t); }
579
580 /// Return @c true if the stored pointer is not null.
581 explicit operator bool() const noexcept
582 { return get() == pointer() ? false : true; }
583
584 // Modifiers.
585
586 /// Release ownership of any stored pointer.
587 pointer
588 release() noexcept
589 {
590 pointer __p = get();
591 std::get<0>(_M_t) = pointer();
592 return __p;
593 }
594
595 /** @brief Replace the stored pointer.
596 *
597 * @param __p The new pointer to store.
598 *
599 * The deleter will be invoked if a pointer is already owned.
600 */
601 template <typename _Up,
602 typename = _Require<
603 __or_<is_same<_Up, pointer>,
604 __and_<is_same<pointer, element_type*>,
605 is_pointer<_Up>,
606 is_convertible<
607 typename remove_pointer<_Up>::type(*)[],
608 element_type(*)[]
609 >
610 >
611 >
612 >>
613 void
614 reset(_Up __p) noexcept
615 {
616 pointer __ptr = __p;
617 using std::swap;
618 swap(std::get<0>(_M_t), __ptr);
619 if (__ptr != nullptr)
620 get_deleter()(__ptr);
621 }
622
623 void reset(nullptr_t = nullptr) noexcept
624 {
625 reset(pointer());
626 }
627
628 /// Exchange the pointer and deleter with another object.
629 void
630 swap(unique_ptr& __u) noexcept
631 {
632 using std::swap;
633 swap(_M_t, __u._M_t);
634 }
635
636 // Disable copy from lvalue.
637 unique_ptr(const unique_ptr&) = delete;
638 unique_ptr& operator=(const unique_ptr&) = delete;
639 };
640
641 template<typename _Tp, typename _Dp>
642 inline void
643 swap(unique_ptr<_Tp, _Dp>& __x,
644 unique_ptr<_Tp, _Dp>& __y) noexcept
645 { __x.swap(__y); }
646
647 template<typename _Tp, typename _Dp,
648 typename _Up, typename _Ep>
649 inline bool
650 operator==(const unique_ptr<_Tp, _Dp>& __x,
651 const unique_ptr<_Up, _Ep>& __y)
652 { return __x.get() == __y.get(); }
653
654 template<typename _Tp, typename _Dp>
655 inline bool
656 operator==(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
657 { return !__x; }
658
659 template<typename _Tp, typename _Dp>
660 inline bool
661 operator==(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
662 { return !__x; }
663
664 template<typename _Tp, typename _Dp,
665 typename _Up, typename _Ep>
666 inline bool
667 operator!=(const unique_ptr<_Tp, _Dp>& __x,
668 const unique_ptr<_Up, _Ep>& __y)
669 { return __x.get() != __y.get(); }
670
671 template<typename _Tp, typename _Dp>
672 inline bool
673 operator!=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
674 { return (bool)__x; }
675
676 template<typename _Tp, typename _Dp>
677 inline bool
678 operator!=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
679 { return (bool)__x; }
680
681 template<typename _Tp, typename _Dp,
682 typename _Up, typename _Ep>
683 inline bool
684 operator<(const unique_ptr<_Tp, _Dp>& __x,
685 const unique_ptr<_Up, _Ep>& __y)
686 {
687 typedef typename
688 std::common_type<typename unique_ptr<_Tp, _Dp>::pointer,
689 typename unique_ptr<_Up, _Ep>::pointer>::type _CT;
690 return std::less<_CT>()(__x.get(), __y.get());
691 }
692
693 template<typename _Tp, typename _Dp>
694 inline bool
695 operator<(const unique_ptr<_Tp, _Dp>& __x, nullptr_t)
696 { return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(__x.get(),
697 nullptr); }
698
699 template<typename _Tp, typename _Dp>
700 inline bool
701 operator<(nullptr_t, const unique_ptr<_Tp, _Dp>& __x)
702 { return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(nullptr,
703 __x.get()); }
704
705 template<typename _Tp, typename _Dp,
706 typename _Up, typename _Ep>
707 inline bool
708 operator<=(const unique_ptr<_Tp, _Dp>& __x,
709 const unique_ptr<_Up, _Ep>& __y)
710 { return !(__y < __x); }
711
712 template<typename _Tp, typename _Dp>
713 inline bool
714 operator<=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t)
715 { return !(nullptr < __x); }
716
717 template<typename _Tp, typename _Dp>
718 inline bool
719 operator<=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x)
720 { return !(__x < nullptr); }
721
722 template<typename _Tp, typename _Dp,
723 typename _Up, typename _Ep>
724 inline bool
725 operator>(const unique_ptr<_Tp, _Dp>& __x,
726 const unique_ptr<_Up, _Ep>& __y)
727 { return (__y < __x); }
728
729 template<typename _Tp, typename _Dp>
730 inline bool
731 operator>(const unique_ptr<_Tp, _Dp>& __x, nullptr_t)
732 { return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(nullptr,
733 __x.get()); }
734
735 template<typename _Tp, typename _Dp>
736 inline bool
737 operator>(nullptr_t, const unique_ptr<_Tp, _Dp>& __x)
738 { return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(__x.get(),
739 nullptr); }
740
741 template<typename _Tp, typename _Dp,
742 typename _Up, typename _Ep>
743 inline bool
744 operator>=(const unique_ptr<_Tp, _Dp>& __x,
745 const unique_ptr<_Up, _Ep>& __y)
746 { return !(__x < __y); }
747
748 template<typename _Tp, typename _Dp>
749 inline bool
750 operator>=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t)
751 { return !(__x < nullptr); }
752
753 template<typename _Tp, typename _Dp>
754 inline bool
755 operator>=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x)
756 { return !(nullptr < __x); }
757
758 /// std::hash specialization for unique_ptr.
759 template<typename _Tp, typename _Dp>
760 struct hash<unique_ptr<_Tp, _Dp>>
761 : public __hash_base<size_t, unique_ptr<_Tp, _Dp>>
762 {
763 size_t
764 operator()(const unique_ptr<_Tp, _Dp>& __u) const noexcept
765 {
766 typedef unique_ptr<_Tp, _Dp> _UP;
767 return std::hash<typename _UP::pointer>()(__u.get());
768 }
769 };
770
771#if __cplusplus201402L > 201103L
772
773#define __cpp_lib_make_unique201304 201304
774
775 template<typename _Tp>
776 struct _MakeUniq
777 { typedef unique_ptr<_Tp> __single_object; };
778
779 template<typename _Tp>
780 struct _MakeUniq<_Tp[]>
781 { typedef unique_ptr<_Tp[]> __array; };
782
783 template<typename _Tp, size_t _Bound>
784 struct _MakeUniq<_Tp[_Bound]>
785 { struct __invalid_type { }; };
786
787 /// std::make_unique for single objects
788 template<typename _Tp, typename... _Args>
789 inline typename _MakeUniq<_Tp>::__single_object
790 make_unique(_Args&&... __args)
791 { return unique_ptr<_Tp>(new _Tp(std::forward<_Args>(__args)...)); }
792
793 /// std::make_unique for arrays of unknown bound
794 template<typename _Tp>
795 inline typename _MakeUniq<_Tp>::__array
796 make_unique(size_t __num)
797 { return unique_ptr<_Tp>(new remove_extent_t<_Tp>[__num]()); }
798
799 /// Disable std::make_unique for arrays of known bound
800 template<typename _Tp, typename... _Args>
801 inline typename _MakeUniq<_Tp>::__invalid_type
802 make_unique(_Args&&...) = delete;
803#endif
804
805 // @} group pointer_abstractions
806
807_GLIBCXX_END_NAMESPACE_VERSION
808} // namespace
809
810#endif /* _UNIQUE_PTR_H */