Bug Summary

File:llvm/lib/Analysis/LoopNestAnalysis.cpp
Warning:line 313, column 3
Returning null reference

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name LoopNestAnalysis.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 -mframe-pointer=none -fmath-errno -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/build-llvm/lib/Analysis -resource-dir /usr/lib/llvm-14/lib/clang/14.0.0 -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/build-llvm/lib/Analysis -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/llvm/lib/Analysis -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/build-llvm/include -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/llvm/include -D NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/x86_64-linux-gnu/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/backward -internal-isystem /usr/lib/llvm-14/lib/clang/14.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/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-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/build-llvm/lib/Analysis -fdebug-prefix-map=/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e=. -ferror-limit 19 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2021-09-04-040900-46481-1 -x c++ /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/llvm/lib/Analysis/LoopNestAnalysis.cpp

/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/llvm/lib/Analysis/LoopNestAnalysis.cpp

1//===- LoopNestAnalysis.cpp - Loop Nest Analysis --------------------------==//
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/// \file
10/// The implementation for the loop nest analysis.
11///
12//===----------------------------------------------------------------------===//
13
14#include "llvm/Analysis/LoopNestAnalysis.h"
15#include "llvm/ADT/BreadthFirstIterator.h"
16#include "llvm/ADT/Statistic.h"
17#include "llvm/Analysis/PostDominators.h"
18#include "llvm/Analysis/ValueTracking.h"
19
20using namespace llvm;
21
22#define DEBUG_TYPE"loopnest" "loopnest"
23#ifndef NDEBUG1
24static const char *VerboseDebug = DEBUG_TYPE"loopnest" "-verbose";
25#endif
26
27/// Determine whether the loops structure violates basic requirements for
28/// perfect nesting:
29/// - the inner loop should be the outer loop's only child
30/// - the outer loop header should 'flow' into the inner loop preheader
31/// or jump around the inner loop to the outer loop latch
32/// - if the inner loop latch exits the inner loop, it should 'flow' into
33/// the outer loop latch.
34/// Returns true if the loop structure satisfies the basic requirements and
35/// false otherwise.
36static bool checkLoopsStructure(const Loop &OuterLoop, const Loop &InnerLoop,
37 ScalarEvolution &SE);
38
39//===----------------------------------------------------------------------===//
40// LoopNest implementation
41//
42
43LoopNest::LoopNest(Loop &Root, ScalarEvolution &SE)
44 : MaxPerfectDepth(getMaxPerfectDepth(Root, SE)) {
4
Calling 'LoopNest::getMaxPerfectDepth'
45 append_range(Loops, breadth_first(&Root));
46}
47
48std::unique_ptr<LoopNest> LoopNest::getLoopNest(Loop &Root,
49 ScalarEvolution &SE) {
50 return std::make_unique<LoopNest>(Root, SE);
2
Calling 'make_unique<llvm::LoopNest, llvm::Loop &, llvm::ScalarEvolution &>'
51}
52
53static CmpInst *getOuterLoopLatchCmp(const Loop &OuterLoop) {
54
55 const BasicBlock *Latch = OuterLoop.getLoopLatch();
56 assert(Latch && "Expecting a valid loop latch")(static_cast<void> (0));
57
58 const BranchInst *BI = dyn_cast<BranchInst>(Latch->getTerminator());
59 assert(BI && BI->isConditional() &&(static_cast<void> (0))
60 "Expecting loop latch terminator to be a branch instruction")(static_cast<void> (0));
61
62 CmpInst *OuterLoopLatchCmp = dyn_cast<CmpInst>(BI->getCondition());
63 DEBUG_WITH_TYPE(do { } while (false)
64 VerboseDebug, if (OuterLoopLatchCmp) {do { } while (false)
65 dbgs() << "Outer loop latch compare instruction: " << *OuterLoopLatchCmpdo { } while (false)
66 << "\n";do { } while (false)
67 })do { } while (false);
68 return OuterLoopLatchCmp;
69}
70
71static CmpInst *getInnerLoopGuardCmp(const Loop &InnerLoop) {
72
73 BranchInst *InnerGuard = InnerLoop.getLoopGuardBranch();
74 CmpInst *InnerLoopGuardCmp =
75 (InnerGuard) ? dyn_cast<CmpInst>(InnerGuard->getCondition()) : nullptr;
76
77 DEBUG_WITH_TYPE(do { } while (false)
78 VerboseDebug, if (InnerLoopGuardCmp) {do { } while (false)
79 dbgs() << "Inner loop guard compare instruction: " << *InnerLoopGuardCmpdo { } while (false)
80 << "\n";do { } while (false)
81 })do { } while (false);
82 return InnerLoopGuardCmp;
83}
84
85static bool checkSafeInstruction(const Instruction &I,
86 const CmpInst *InnerLoopGuardCmp,
87 const CmpInst *OuterLoopLatchCmp,
88 Optional<Loop::LoopBounds> OuterLoopLB) {
89
90 bool IsAllowed =
91 isSafeToSpeculativelyExecute(&I) || isa<PHINode>(I) || isa<BranchInst>(I);
92 if (!IsAllowed)
93 return false;
94 // The only binary instruction allowed is the outer loop step instruction,
95 // the only comparison instructions allowed are the inner loop guard
96 // compare instruction and the outer loop latch compare instruction.
97 if ((isa<BinaryOperator>(I) && &I != &OuterLoopLB->getStepInst()) ||
98 (isa<CmpInst>(I) && &I != OuterLoopLatchCmp && &I != InnerLoopGuardCmp)) {
99 return false;
100 }
101 return true;
102}
103
104bool LoopNest::arePerfectlyNested(const Loop &OuterLoop, const Loop &InnerLoop,
105 ScalarEvolution &SE) {
106 return (analyzeLoopNestForPerfectNest(OuterLoop, InnerLoop, SE) ==
9
Calling 'LoopNest::analyzeLoopNestForPerfectNest'
107 PerfectLoopNest);
108}
109
110LoopNest::LoopNestEnum LoopNest::analyzeLoopNestForPerfectNest(
111 const Loop &OuterLoop, const Loop &InnerLoop, ScalarEvolution &SE) {
112
113 assert(!OuterLoop.isInnermost() && "Outer loop should have subloops")(static_cast<void> (0));
114 assert(!InnerLoop.isOutermost() && "Inner loop should have a parent")(static_cast<void> (0));
115 LLVM_DEBUG(dbgs() << "Checking whether loop '" << OuterLoop.getName()do { } while (false)
10
Loop condition is false. Exiting loop
116 << "' and '" << InnerLoop.getName()do { } while (false)
117 << "' are perfectly nested.\n")do { } while (false);
118
119 // Determine whether the loops structure satisfies the following requirements:
120 // - the inner loop should be the outer loop's only child
121 // - the outer loop header should 'flow' into the inner loop preheader
122 // or jump around the inner loop to the outer loop latch
123 // - if the inner loop latch exits the inner loop, it should 'flow' into
124 // the outer loop latch.
125 if (!checkLoopsStructure(OuterLoop, InnerLoop, SE)) {
11
Calling 'checkLoopsStructure'
126 LLVM_DEBUG(dbgs() << "Not perfectly nested: invalid loop structure.\n")do { } while (false);
127 return InvalidLoopStructure;
128 }
129
130 // Bail out if we cannot retrieve the outer loop bounds.
131 auto OuterLoopLB = OuterLoop.getBounds(SE);
132 if (OuterLoopLB == None) {
133 LLVM_DEBUG(dbgs() << "Cannot compute loop bounds of OuterLoop: "do { } while (false)
134 << OuterLoop << "\n";)do { } while (false);
135 return OuterLoopLowerBoundUnknown;
136 }
137
138 CmpInst *OuterLoopLatchCmp = getOuterLoopLatchCmp(OuterLoop);
139 CmpInst *InnerLoopGuardCmp = getInnerLoopGuardCmp(InnerLoop);
140
141 // Determine whether instructions in a basic block are one of:
142 // - the inner loop guard comparison
143 // - the outer loop latch comparison
144 // - the outer loop induction variable increment
145 // - a phi node, a cast or a branch
146 auto containsOnlySafeInstructions = [&](const BasicBlock &BB) {
147 return llvm::all_of(BB, [&](const Instruction &I) {
148 bool IsSafeInstr = checkSafeInstruction(I, InnerLoopGuardCmp,
149 OuterLoopLatchCmp, OuterLoopLB);
150 if (IsSafeInstr) {
151 DEBUG_WITH_TYPE(VerboseDebug, {do { } while (false)
152 dbgs() << "Instruction: " << I << "\nin basic block:" << BBdo { } while (false)
153 << "is unsafe.\n";do { } while (false)
154 })do { } while (false);
155 }
156 return IsSafeInstr;
157 });
158 };
159
160 // Check the code surrounding the inner loop for instructions that are deemed
161 // unsafe.
162 const BasicBlock *OuterLoopHeader = OuterLoop.getHeader();
163 const BasicBlock *OuterLoopLatch = OuterLoop.getLoopLatch();
164 const BasicBlock *InnerLoopPreHeader = InnerLoop.getLoopPreheader();
165
166 if (!containsOnlySafeInstructions(*OuterLoopHeader) ||
167 !containsOnlySafeInstructions(*OuterLoopLatch) ||
168 (InnerLoopPreHeader != OuterLoopHeader &&
169 !containsOnlySafeInstructions(*InnerLoopPreHeader)) ||
170 !containsOnlySafeInstructions(*InnerLoop.getExitBlock())) {
171 LLVM_DEBUG(dbgs() << "Not perfectly nested: code surrounding inner loop is "do { } while (false)
172 "unsafe\n";)do { } while (false);
173 return ImperfectLoopNest;
174 }
175
176 LLVM_DEBUG(dbgs() << "Loop '" << OuterLoop.getName() << "' and '"do { } while (false)
177 << InnerLoop.getName() << "' are perfectly nested.\n")do { } while (false);
178
179 return PerfectLoopNest;
180}
181
182LoopNest::InstrVectorTy LoopNest::getInterveningInstructions(
183 const Loop &OuterLoop, const Loop &InnerLoop, ScalarEvolution &SE) {
184 InstrVectorTy Instr;
185 switch (analyzeLoopNestForPerfectNest(OuterLoop, InnerLoop, SE)) {
186 case PerfectLoopNest:
187 LLVM_DEBUG(dbgs() << "The loop Nest is Perfect, returning empty "do { } while (false)
188 "instruction vector. \n";)do { } while (false);
189 return Instr;
190
191 case InvalidLoopStructure:
192 LLVM_DEBUG(dbgs() << "Not perfectly nested: invalid loop structure. "do { } while (false)
193 "Instruction vector is empty.\n";)do { } while (false);
194 return Instr;
195
196 case OuterLoopLowerBoundUnknown:
197 LLVM_DEBUG(dbgs() << "Cannot compute loop bounds of OuterLoop: "do { } while (false)
198 << OuterLoop << "\nInstruction vector is empty.\n";)do { } while (false);
199 return Instr;
200
201 case ImperfectLoopNest:
202 break;
203 }
204
205 // Identify the outer loop latch comparison instruction.
206 auto OuterLoopLB = OuterLoop.getBounds(SE);
207
208 CmpInst *OuterLoopLatchCmp = getOuterLoopLatchCmp(OuterLoop);
209 CmpInst *InnerLoopGuardCmp = getInnerLoopGuardCmp(InnerLoop);
210
211 auto GetUnsafeInstructions = [&](const BasicBlock &BB) {
212 for (const Instruction &I : BB) {
213 if (!checkSafeInstruction(I, InnerLoopGuardCmp, OuterLoopLatchCmp,
214 OuterLoopLB)) {
215 Instr.push_back(&I);
216 DEBUG_WITH_TYPE(VerboseDebug, {do { } while (false)
217 dbgs() << "Instruction: " << I << "\nin basic block:" << BBdo { } while (false)
218 << "is unsafe.\n";do { } while (false)
219 })do { } while (false);
220 }
221 }
222 };
223
224 // Check the code surrounding the inner loop for instructions that are deemed
225 // unsafe.
226 const BasicBlock *OuterLoopHeader = OuterLoop.getHeader();
227 const BasicBlock *OuterLoopLatch = OuterLoop.getLoopLatch();
228 const BasicBlock *InnerLoopPreHeader = InnerLoop.getLoopPreheader();
229 const BasicBlock *InnerLoopExitBlock = InnerLoop.getExitBlock();
230
231 GetUnsafeInstructions(*OuterLoopHeader);
232 GetUnsafeInstructions(*OuterLoopLatch);
233 GetUnsafeInstructions(*InnerLoopExitBlock);
234
235 if (InnerLoopPreHeader != OuterLoopHeader) {
236 GetUnsafeInstructions(*InnerLoopPreHeader);
237 }
238 return Instr;
239}
240
241SmallVector<LoopVectorTy, 4>
242LoopNest::getPerfectLoops(ScalarEvolution &SE) const {
243 SmallVector<LoopVectorTy, 4> LV;
244 LoopVectorTy PerfectNest;
245
246 for (Loop *L : depth_first(const_cast<Loop *>(Loops.front()))) {
247 if (PerfectNest.empty())
248 PerfectNest.push_back(L);
249
250 auto &SubLoops = L->getSubLoops();
251 if (SubLoops.size() == 1 && arePerfectlyNested(*L, *SubLoops.front(), SE)) {
252 PerfectNest.push_back(SubLoops.front());
253 } else {
254 LV.push_back(PerfectNest);
255 PerfectNest.clear();
256 }
257 }
258
259 return LV;
260}
261
262unsigned LoopNest::getMaxPerfectDepth(const Loop &Root, ScalarEvolution &SE) {
263 LLVM_DEBUG(dbgs() << "Get maximum perfect depth of loop nest rooted by loop '"do { } while (false)
5
Loop condition is false. Exiting loop
264 << Root.getName() << "'\n")do { } while (false);
265
266 const Loop *CurrentLoop = &Root;
267 const auto *SubLoops = &CurrentLoop->getSubLoops();
268 unsigned CurrentDepth = 1;
269
270 while (SubLoops->size() == 1) {
6
Assuming the condition is true
7
Loop condition is true. Entering loop body
271 const Loop *InnerLoop = SubLoops->front();
272 if (!arePerfectlyNested(*CurrentLoop, *InnerLoop, SE)) {
8
Calling 'LoopNest::arePerfectlyNested'
273 LLVM_DEBUG({do { } while (false)
274 dbgs() << "Not a perfect nest: loop '" << CurrentLoop->getName()do { } while (false)
275 << "' is not perfectly nested with loop '"do { } while (false)
276 << InnerLoop->getName() << "'\n";do { } while (false)
277 })do { } while (false);
278 break;
279 }
280
281 CurrentLoop = InnerLoop;
282 SubLoops = &CurrentLoop->getSubLoops();
283 ++CurrentDepth;
284 }
285
286 return CurrentDepth;
287}
288
289const BasicBlock &LoopNest::skipEmptyBlockUntil(const BasicBlock *From,
290 const BasicBlock *End,
291 bool CheckUniquePred) {
292 assert(From && "Expecting valid From")(static_cast<void> (0));
293 assert(End && "Expecting valid End")(static_cast<void> (0));
294
295 if (From
23.1
'From' is not equal to 'End'
23.1
'From' is not equal to 'End'
== End || !From->getUniqueSuccessor())
24
Assuming the condition is false
25
Taking false branch
296 return *From;
297
298 auto IsEmpty = [](const BasicBlock *BB) {
299 return (BB->getInstList().size() == 1);
300 };
301
302 // Visited is used to avoid running into an infinite loop.
303 SmallPtrSet<const BasicBlock *, 4> Visited;
304 const BasicBlock *BB = From->getUniqueSuccessor();
305 const BasicBlock *PredBB = From;
306 while (BB && BB != End && IsEmpty(BB) && !Visited.count(BB) &&
26
Assuming 'BB' is null
307 (!CheckUniquePred || BB->getUniquePredecessor())) {
308 Visited.insert(BB);
309 PredBB = BB;
310 BB = BB->getUniqueSuccessor();
311 }
312
313 return (BB == End) ? *End : *PredBB;
27
Assuming 'BB' is equal to 'End'
28
'?' condition is true
29
Returning null reference
314}
315
316static bool checkLoopsStructure(const Loop &OuterLoop, const Loop &InnerLoop,
317 ScalarEvolution &SE) {
318 // The inner loop must be the only outer loop's child.
319 if ((OuterLoop.getSubLoops().size() != 1) ||
12
Assuming the condition is false
320 (InnerLoop.getParentLoop() != &OuterLoop))
13
Assuming the condition is false
321 return false;
322
323 // We expect loops in normal form which have a preheader, header, latch...
324 if (!OuterLoop.isLoopSimplifyForm() || !InnerLoop.isLoopSimplifyForm())
14
Assuming the condition is false
15
Assuming the condition is false
16
Taking false branch
325 return false;
326
327 const BasicBlock *OuterLoopHeader = OuterLoop.getHeader();
328 const BasicBlock *OuterLoopLatch = OuterLoop.getLoopLatch();
329 const BasicBlock *InnerLoopPreHeader = InnerLoop.getLoopPreheader();
330 const BasicBlock *InnerLoopLatch = InnerLoop.getLoopLatch();
331 const BasicBlock *InnerLoopExit = InnerLoop.getExitBlock();
332
333 // We expect rotated loops. The inner loop should have a single exit block.
334 if (OuterLoop.getExitingBlock() != OuterLoopLatch ||
17
Assuming the condition is false
20
Taking false branch
335 InnerLoop.getExitingBlock() != InnerLoopLatch || !InnerLoopExit)
18
Assuming the condition is false
19
Assuming 'InnerLoopExit' is non-null
336 return false;
337
338 // Returns whether the block `ExitBlock` contains at least one LCSSA Phi node.
339 auto ContainsLCSSAPhi = [](const BasicBlock &ExitBlock) {
340 return any_of(ExitBlock.phis(), [](const PHINode &PN) {
341 return PN.getNumIncomingValues() == 1;
342 });
343 };
344
345 // Returns whether the block `BB` qualifies for being an extra Phi block. The
346 // extra Phi block is the additional block inserted after the exit block of an
347 // "guarded" inner loop which contains "only" Phi nodes corresponding to the
348 // LCSSA Phi nodes in the exit block.
349 auto IsExtraPhiBlock = [&](const BasicBlock &BB) {
350 return BB.getFirstNonPHI() == BB.getTerminator() &&
351 all_of(BB.phis(), [&](const PHINode &PN) {
352 return all_of(PN.blocks(), [&](const BasicBlock *IncomingBlock) {
353 return IncomingBlock == InnerLoopExit ||
354 IncomingBlock == OuterLoopHeader;
355 });
356 });
357 };
358
359 const BasicBlock *ExtraPhiBlock = nullptr;
360 // Ensure the only branch that may exist between the loops is the inner loop
361 // guard.
362 if (OuterLoopHeader != InnerLoopPreHeader) {
21
Assuming 'OuterLoopHeader' is not equal to 'InnerLoopPreHeader'
22
Taking true branch
363 const BasicBlock &SingleSucc =
364 LoopNest::skipEmptyBlockUntil(OuterLoopHeader, InnerLoopPreHeader);
23
Calling 'LoopNest::skipEmptyBlockUntil'
365
366 // no conditional branch present
367 if (&SingleSucc != InnerLoopPreHeader) {
368 const BranchInst *BI = dyn_cast<BranchInst>(SingleSucc.getTerminator());
369
370 if (!BI || BI != InnerLoop.getLoopGuardBranch())
371 return false;
372
373 bool InnerLoopExitContainsLCSSA = ContainsLCSSAPhi(*InnerLoopExit);
374
375 // The successors of the inner loop guard should be the inner loop
376 // preheader or the outer loop latch possibly through empty blocks.
377 for (const BasicBlock *Succ : BI->successors()) {
378 const BasicBlock *PotentialInnerPreHeader = Succ;
379 const BasicBlock *PotentialOuterLatch = Succ;
380
381 // Ensure the inner loop guard successor is empty before skipping
382 // blocks.
383 if (Succ->getInstList().size() == 1) {
384 PotentialInnerPreHeader =
385 &LoopNest::skipEmptyBlockUntil(Succ, InnerLoopPreHeader);
386 PotentialOuterLatch =
387 &LoopNest::skipEmptyBlockUntil(Succ, OuterLoopLatch);
388 }
389
390 if (PotentialInnerPreHeader == InnerLoopPreHeader)
391 continue;
392 if (PotentialOuterLatch == OuterLoopLatch)
393 continue;
394
395 // If `InnerLoopExit` contains LCSSA Phi instructions, additional block
396 // may be inserted before the `OuterLoopLatch` to which `BI` jumps. The
397 // loops are still considered perfectly nested if the extra block only
398 // contains Phi instructions from InnerLoopExit and OuterLoopHeader.
399 if (InnerLoopExitContainsLCSSA && IsExtraPhiBlock(*Succ) &&
400 Succ->getSingleSuccessor() == OuterLoopLatch) {
401 // Points to the extra block so that we can reference it later in the
402 // final check. We can also conclude that the inner loop is
403 // guarded and there exists LCSSA Phi node in the exit block later if
404 // we see a non-null `ExtraPhiBlock`.
405 ExtraPhiBlock = Succ;
406 continue;
407 }
408
409 DEBUG_WITH_TYPE(VerboseDebug, {do { } while (false)
410 dbgs() << "Inner loop guard successor " << Succ->getName()do { } while (false)
411 << " doesn't lead to inner loop preheader or "do { } while (false)
412 "outer loop latch.\n";do { } while (false)
413 })do { } while (false);
414 return false;
415 }
416 }
417 }
418
419 // Ensure the inner loop exit block lead to the outer loop latch possibly
420 // through empty blocks.
421 if ((!ExtraPhiBlock ||
422 &LoopNest::skipEmptyBlockUntil(InnerLoop.getExitBlock(),
423 ExtraPhiBlock) != ExtraPhiBlock) &&
424 (&LoopNest::skipEmptyBlockUntil(InnerLoop.getExitBlock(),
425 OuterLoopLatch) != OuterLoopLatch)) {
426 DEBUG_WITH_TYPE(do { } while (false)
427 VerboseDebug,do { } while (false)
428 dbgs() << "Inner loop exit block " << *InnerLoopExitdo { } while (false)
429 << " does not directly lead to the outer loop latch.\n";)do { } while (false);
430 return false;
431 }
432
433 return true;
434}
435
436AnalysisKey LoopNestAnalysis::Key;
437
438raw_ostream &llvm::operator<<(raw_ostream &OS, const LoopNest &LN) {
439 OS << "IsPerfect=";
440 if (LN.getMaxPerfectDepth() == LN.getNestDepth())
441 OS << "true";
442 else
443 OS << "false";
444 OS << ", Depth=" << LN.getNestDepth();
445 OS << ", OutermostLoop: " << LN.getOutermostLoop().getName();
446 OS << ", Loops: ( ";
447 for (const Loop *L : LN.getLoops())
448 OS << L->getName() << " ";
449 OS << ")";
450
451 return OS;
452}
453
454//===----------------------------------------------------------------------===//
455// LoopNestPrinterPass implementation
456//
457
458PreservedAnalyses LoopNestPrinterPass::run(Loop &L, LoopAnalysisManager &AM,
459 LoopStandardAnalysisResults &AR,
460 LPMUpdater &U) {
461 if (auto LN = LoopNest::getLoopNest(L, AR.SE))
1
Calling 'LoopNest::getLoopNest'
462 OS << *LN << "\n";
463
464 return PreservedAnalyses::all();
465}

/usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/bits/unique_ptr.h

1// unique_ptr implementation -*- C++ -*-
2
3// Copyright (C) 2008-2020 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#include <bits/stl_function.h>
39#include <bits/functional_hash.h>
40#if __cplusplus201402L > 201703L
41# include <compare>
42# include <ostream>
43#endif
44
45namespace std _GLIBCXX_VISIBILITY(default)__attribute__ ((__visibility__ ("default")))
46{
47_GLIBCXX_BEGIN_NAMESPACE_VERSION
48
49 /**
50 * @addtogroup pointer_abstractions
51 * @{
52 */
53
54#if _GLIBCXX_USE_DEPRECATED1
55#pragma GCC diagnostic push
56#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
57 template<typename> class auto_ptr;
58#pragma GCC diagnostic pop
59#endif
60
61 /// Primary template of default_delete, used by unique_ptr for single objects
62 template<typename _Tp>
63 struct default_delete
64 {
65 /// Default constructor
66 constexpr default_delete() noexcept = default;
67
68 /** @brief Converting constructor.
69 *
70 * Allows conversion from a deleter for objects of another type, `_Up`,
71 * only if `_Up*` is convertible to `_Tp*`.
72 */
73 template<typename _Up,
74 typename = _Require<is_convertible<_Up*, _Tp*>>>
75 default_delete(const default_delete<_Up>&) noexcept { }
76
77 /// Calls `delete __ptr`
78 void
79 operator()(_Tp* __ptr) const
80 {
81 static_assert(!is_void<_Tp>::value,
82 "can't delete pointer to incomplete type");
83 static_assert(sizeof(_Tp)>0,
84 "can't delete pointer to incomplete type");
85 delete __ptr;
86 }
87 };
88
89 // _GLIBCXX_RESOLVE_LIB_DEFECTS
90 // DR 740 - omit specialization for array objects with a compile time length
91
92 /// Specialization of default_delete for arrays, used by `unique_ptr<T[]>`
93 template<typename _Tp>
94 struct default_delete<_Tp[]>
95 {
96 public:
97 /// Default constructor
98 constexpr default_delete() noexcept = default;
99
100 /** @brief Converting constructor.
101 *
102 * Allows conversion from a deleter for arrays of another type, such as
103 * a const-qualified version of `_Tp`.
104 *
105 * Conversions from types derived from `_Tp` are not allowed because
106 * it is undefined to `delete[]` an array of derived types through a
107 * pointer to the base type.
108 */
109 template<typename _Up,
110 typename = _Require<is_convertible<_Up(*)[], _Tp(*)[]>>>
111 default_delete(const default_delete<_Up[]>&) noexcept { }
112
113 /// Calls `delete[] __ptr`
114 template<typename _Up>
115 typename enable_if<is_convertible<_Up(*)[], _Tp(*)[]>::value>::type
116 operator()(_Up* __ptr) const
117 {
118 static_assert(sizeof(_Tp)>0,
119 "can't delete pointer to incomplete type");
120 delete [] __ptr;
121 }
122 };
123
124 /// @cond undocumented
125
126 // Manages the pointer and deleter of a unique_ptr
127 template <typename _Tp, typename _Dp>
128 class __uniq_ptr_impl
129 {
130 template <typename _Up, typename _Ep, typename = void>
131 struct _Ptr
132 {
133 using type = _Up*;
134 };
135
136 template <typename _Up, typename _Ep>
137 struct
138 _Ptr<_Up, _Ep, __void_t<typename remove_reference<_Ep>::type::pointer>>
139 {
140 using type = typename remove_reference<_Ep>::type::pointer;
141 };
142
143 public:
144 using _DeleterConstraint = enable_if<
145 __and_<__not_<is_pointer<_Dp>>,
146 is_default_constructible<_Dp>>::value>;
147
148 using pointer = typename _Ptr<_Tp, _Dp>::type;
149
150 static_assert( !is_rvalue_reference<_Dp>::value,
151 "unique_ptr's deleter type must be a function object type"
152 " or an lvalue reference type" );
153
154 __uniq_ptr_impl() = default;
155 __uniq_ptr_impl(pointer __p) : _M_t() { _M_ptr() = __p; }
156
157 template<typename _Del>
158 __uniq_ptr_impl(pointer __p, _Del&& __d)
159 : _M_t(__p, std::forward<_Del>(__d)) { }
160
161 __uniq_ptr_impl(__uniq_ptr_impl&& __u) noexcept
162 : _M_t(std::move(__u._M_t))
163 { __u._M_ptr() = nullptr; }
164
165 __uniq_ptr_impl& operator=(__uniq_ptr_impl&& __u) noexcept
166 {
167 reset(__u.release());
168 _M_deleter() = std::forward<_Dp>(__u._M_deleter());
169 return *this;
170 }
171
172 pointer& _M_ptr() { return std::get<0>(_M_t); }
173 pointer _M_ptr() const { return std::get<0>(_M_t); }
174 _Dp& _M_deleter() { return std::get<1>(_M_t); }
175 const _Dp& _M_deleter() const { return std::get<1>(_M_t); }
176
177 void reset(pointer __p) noexcept
178 {
179 const pointer __old_p = _M_ptr();
180 _M_ptr() = __p;
181 if (__old_p)
182 _M_deleter()(__old_p);
183 }
184
185 pointer release() noexcept
186 {
187 pointer __p = _M_ptr();
188 _M_ptr() = nullptr;
189 return __p;
190 }
191
192 void
193 swap(__uniq_ptr_impl& __rhs) noexcept
194 {
195 using std::swap;
196 swap(this->_M_ptr(), __rhs._M_ptr());
197 swap(this->_M_deleter(), __rhs._M_deleter());
198 }
199
200 private:
201 tuple<pointer, _Dp> _M_t;
202 };
203
204 // Defines move construction + assignment as either defaulted or deleted.
205 template <typename _Tp, typename _Dp,
206 bool = is_move_constructible<_Dp>::value,
207 bool = is_move_assignable<_Dp>::value>
208 struct __uniq_ptr_data : __uniq_ptr_impl<_Tp, _Dp>
209 {
210 using __uniq_ptr_impl<_Tp, _Dp>::__uniq_ptr_impl;
211 __uniq_ptr_data(__uniq_ptr_data&&) = default;
212 __uniq_ptr_data& operator=(__uniq_ptr_data&&) = default;
213 };
214
215 template <typename _Tp, typename _Dp>
216 struct __uniq_ptr_data<_Tp, _Dp, true, false> : __uniq_ptr_impl<_Tp, _Dp>
217 {
218 using __uniq_ptr_impl<_Tp, _Dp>::__uniq_ptr_impl;
219 __uniq_ptr_data(__uniq_ptr_data&&) = default;
220 __uniq_ptr_data& operator=(__uniq_ptr_data&&) = delete;
221 };
222
223 template <typename _Tp, typename _Dp>
224 struct __uniq_ptr_data<_Tp, _Dp, false, true> : __uniq_ptr_impl<_Tp, _Dp>
225 {
226 using __uniq_ptr_impl<_Tp, _Dp>::__uniq_ptr_impl;
227 __uniq_ptr_data(__uniq_ptr_data&&) = delete;
228 __uniq_ptr_data& operator=(__uniq_ptr_data&&) = default;
229 };
230
231 template <typename _Tp, typename _Dp>
232 struct __uniq_ptr_data<_Tp, _Dp, false, false> : __uniq_ptr_impl<_Tp, _Dp>
233 {
234 using __uniq_ptr_impl<_Tp, _Dp>::__uniq_ptr_impl;
235 __uniq_ptr_data(__uniq_ptr_data&&) = delete;
236 __uniq_ptr_data& operator=(__uniq_ptr_data&&) = delete;
237 };
238 /// @endcond
239
240 /// 20.7.1.2 unique_ptr for single objects.
241 template <typename _Tp, typename _Dp = default_delete<_Tp>>
242 class unique_ptr
243 {
244 template <typename _Up>
245 using _DeleterConstraint =
246 typename __uniq_ptr_impl<_Tp, _Up>::_DeleterConstraint::type;
247
248 __uniq_ptr_data<_Tp, _Dp> _M_t;
249
250 public:
251 using pointer = typename __uniq_ptr_impl<_Tp, _Dp>::pointer;
252 using element_type = _Tp;
253 using deleter_type = _Dp;
254
255 private:
256 // helper template for detecting a safe conversion from another
257 // unique_ptr
258 template<typename _Up, typename _Ep>
259 using __safe_conversion_up = __and_<
260 is_convertible<typename unique_ptr<_Up, _Ep>::pointer, pointer>,
261 __not_<is_array<_Up>>
262 >;
263
264 public:
265 // Constructors.
266
267 /// Default constructor, creates a unique_ptr that owns nothing.
268 template<typename _Del = _Dp, typename = _DeleterConstraint<_Del>>
269 constexpr unique_ptr() noexcept
270 : _M_t()
271 { }
272
273 /** Takes ownership of a pointer.
274 *
275 * @param __p A pointer to an object of @c element_type
276 *
277 * The deleter will be value-initialized.
278 */
279 template<typename _Del = _Dp, typename = _DeleterConstraint<_Del>>
280 explicit
281 unique_ptr(pointer __p) noexcept
282 : _M_t(__p)
283 { }
284
285 /** Takes ownership of a pointer.
286 *
287 * @param __p A pointer to an object of @c element_type
288 * @param __d A reference to a deleter.
289 *
290 * The deleter will be initialized with @p __d
291 */
292 template<typename _Del = deleter_type,
293 typename = _Require<is_copy_constructible<_Del>>>
294 unique_ptr(pointer __p, const deleter_type& __d) noexcept
295 : _M_t(__p, __d) { }
296
297 /** Takes ownership of a pointer.
298 *
299 * @param __p A pointer to an object of @c element_type
300 * @param __d An rvalue reference to a (non-reference) deleter.
301 *
302 * The deleter will be initialized with @p std::move(__d)
303 */
304 template<typename _Del = deleter_type,
305 typename = _Require<is_move_constructible<_Del>>>
306 unique_ptr(pointer __p,
307 __enable_if_t<!is_lvalue_reference<_Del>::value,
308 _Del&&> __d) noexcept
309 : _M_t(__p, std::move(__d))
310 { }
311
312 template<typename _Del = deleter_type,
313 typename _DelUnref = typename remove_reference<_Del>::type>
314 unique_ptr(pointer,
315 __enable_if_t<is_lvalue_reference<_Del>::value,
316 _DelUnref&&>) = delete;
317
318 /// Creates a unique_ptr that owns nothing.
319 template<typename _Del = _Dp, typename = _DeleterConstraint<_Del>>
320 constexpr unique_ptr(nullptr_t) noexcept
321 : _M_t()
322 { }
323
324 // Move constructors.
325
326 /// Move constructor.
327 unique_ptr(unique_ptr&&) = default;
328
329 /** @brief Converting constructor from another type
330 *
331 * Requires that the pointer owned by @p __u is convertible to the
332 * type of pointer owned by this object, @p __u does not own an array,
333 * and @p __u has a compatible deleter type.
334 */
335 template<typename _Up, typename _Ep, typename = _Require<
336 __safe_conversion_up<_Up, _Ep>,
337 typename conditional<is_reference<_Dp>::value,
338 is_same<_Ep, _Dp>,
339 is_convertible<_Ep, _Dp>>::type>>
340 unique_ptr(unique_ptr<_Up, _Ep>&& __u) noexcept
341 : _M_t(__u.release(), std::forward<_Ep>(__u.get_deleter()))
342 { }
343
344#if _GLIBCXX_USE_DEPRECATED1
345#pragma GCC diagnostic push
346#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
347 /// Converting constructor from @c auto_ptr
348 template<typename _Up, typename = _Require<
349 is_convertible<_Up*, _Tp*>, is_same<_Dp, default_delete<_Tp>>>>
350 unique_ptr(auto_ptr<_Up>&& __u) noexcept;
351#pragma GCC diagnostic pop
352#endif
353
354 /// Destructor, invokes the deleter if the stored pointer is not null.
355 ~unique_ptr() noexcept
356 {
357 static_assert(__is_invocable<deleter_type&, pointer>::value,
358 "unique_ptr's deleter must be invocable with a pointer");
359 auto& __ptr = _M_t._M_ptr();
360 if (__ptr != nullptr)
361 get_deleter()(std::move(__ptr));
362 __ptr = pointer();
363 }
364
365 // Assignment.
366
367 /** @brief Move assignment operator.
368 *
369 * Invokes the deleter if this object owns a pointer.
370 */
371 unique_ptr& operator=(unique_ptr&&) = default;
372
373 /** @brief Assignment from another type.
374 *
375 * @param __u The object to transfer ownership from, which owns a
376 * convertible pointer to a non-array object.
377 *
378 * Invokes the deleter if this object owns a pointer.
379 */
380 template<typename _Up, typename _Ep>
381 typename enable_if< __and_<
382 __safe_conversion_up<_Up, _Ep>,
383 is_assignable<deleter_type&, _Ep&&>
384 >::value,
385 unique_ptr&>::type
386 operator=(unique_ptr<_Up, _Ep>&& __u) noexcept
387 {
388 reset(__u.release());
389 get_deleter() = std::forward<_Ep>(__u.get_deleter());
390 return *this;
391 }
392
393 /// Reset the %unique_ptr to empty, invoking the deleter if necessary.
394 unique_ptr&
395 operator=(nullptr_t) noexcept
396 {
397 reset();
398 return *this;
399 }
400
401 // Observers.
402
403 /// Dereference the stored pointer.
404 typename add_lvalue_reference<element_type>::type
405 operator*() const
406 {
407 __glibcxx_assert(get() != pointer());
408 return *get();
409 }
410
411 /// Return the stored pointer.
412 pointer
413 operator->() const noexcept
414 {
415 _GLIBCXX_DEBUG_PEDASSERT(get() != pointer());
416 return get();
417 }
418
419 /// Return the stored pointer.
420 pointer
421 get() const noexcept
422 { return _M_t._M_ptr(); }
423
424 /// Return a reference to the stored deleter.
425 deleter_type&
426 get_deleter() noexcept
427 { return _M_t._M_deleter(); }
428
429 /// Return a reference to the stored deleter.
430 const deleter_type&
431 get_deleter() const noexcept
432 { return _M_t._M_deleter(); }
433
434 /// Return @c true if the stored pointer is not null.
435 explicit operator bool() const noexcept
436 { return get() == pointer() ? false : true; }
437
438 // Modifiers.
439
440 /// Release ownership of any stored pointer.
441 pointer
442 release() noexcept
443 { return _M_t.release(); }
444
445 /** @brief Replace the stored pointer.
446 *
447 * @param __p The new pointer to store.
448 *
449 * The deleter will be invoked if a pointer is already owned.
450 */
451 void
452 reset(pointer __p = pointer()) noexcept
453 {
454 static_assert(__is_invocable<deleter_type&, pointer>::value,
455 "unique_ptr's deleter must be invocable with a pointer");
456 _M_t.reset(std::move(__p));
457 }
458
459 /// Exchange the pointer and deleter with another object.
460 void
461 swap(unique_ptr& __u) noexcept
462 {
463 static_assert(__is_swappable<_Dp>::value, "deleter must be swappable");
464 _M_t.swap(__u._M_t);
465 }
466
467 // Disable copy from lvalue.
468 unique_ptr(const unique_ptr&) = delete;
469 unique_ptr& operator=(const unique_ptr&) = delete;
470 };
471
472 /// 20.7.1.3 unique_ptr for array objects with a runtime length
473 // [unique.ptr.runtime]
474 // _GLIBCXX_RESOLVE_LIB_DEFECTS
475 // DR 740 - omit specialization for array objects with a compile time length
476 template<typename _Tp, typename _Dp>
477 class unique_ptr<_Tp[], _Dp>
478 {
479 template <typename _Up>
480 using _DeleterConstraint =
481 typename __uniq_ptr_impl<_Tp, _Up>::_DeleterConstraint::type;
482
483 __uniq_ptr_data<_Tp, _Dp> _M_t;
484
485 template<typename _Up>
486 using __remove_cv = typename remove_cv<_Up>::type;
487
488 // like is_base_of<_Tp, _Up> but false if unqualified types are the same
489 template<typename _Up>
490 using __is_derived_Tp
491 = __and_< is_base_of<_Tp, _Up>,
492 __not_<is_same<__remove_cv<_Tp>, __remove_cv<_Up>>> >;
493
494 public:
495 using pointer = typename __uniq_ptr_impl<_Tp, _Dp>::pointer;
496 using element_type = _Tp;
497 using deleter_type = _Dp;
498
499 // helper template for detecting a safe conversion from another
500 // unique_ptr
501 template<typename _Up, typename _Ep,
502 typename _UPtr = unique_ptr<_Up, _Ep>,
503 typename _UP_pointer = typename _UPtr::pointer,
504 typename _UP_element_type = typename _UPtr::element_type>
505 using __safe_conversion_up = __and_<
506 is_array<_Up>,
507 is_same<pointer, element_type*>,
508 is_same<_UP_pointer, _UP_element_type*>,
509 is_convertible<_UP_element_type(*)[], element_type(*)[]>
510 >;
511
512 // helper template for detecting a safe conversion from a raw pointer
513 template<typename _Up>
514 using __safe_conversion_raw = __and_<
515 __or_<__or_<is_same<_Up, pointer>,
516 is_same<_Up, nullptr_t>>,
517 __and_<is_pointer<_Up>,
518 is_same<pointer, element_type*>,
519 is_convertible<
520 typename remove_pointer<_Up>::type(*)[],
521 element_type(*)[]>
522 >
523 >
524 >;
525
526 // Constructors.
527
528 /// Default constructor, creates a unique_ptr that owns nothing.
529 template<typename _Del = _Dp, typename = _DeleterConstraint<_Del>>
530 constexpr unique_ptr() noexcept
531 : _M_t()
532 { }
533
534 /** Takes ownership of a pointer.
535 *
536 * @param __p A pointer to an array of a type safely convertible
537 * to an array of @c element_type
538 *
539 * The deleter will be value-initialized.
540 */
541 template<typename _Up,
542 typename _Vp = _Dp,
543 typename = _DeleterConstraint<_Vp>,
544 typename = typename enable_if<
545 __safe_conversion_raw<_Up>::value, bool>::type>
546 explicit
547 unique_ptr(_Up __p) noexcept
548 : _M_t(__p)
549 { }
550
551 /** Takes ownership of a pointer.
552 *
553 * @param __p A pointer to an array of a type safely convertible
554 * to an array of @c element_type
555 * @param __d A reference to a deleter.
556 *
557 * The deleter will be initialized with @p __d
558 */
559 template<typename _Up, typename _Del = deleter_type,
560 typename = _Require<__safe_conversion_raw<_Up>,
561 is_copy_constructible<_Del>>>
562 unique_ptr(_Up __p, const deleter_type& __d) noexcept
563 : _M_t(__p, __d) { }
564
565 /** Takes ownership of a pointer.
566 *
567 * @param __p A pointer to an array of a type safely convertible
568 * to an array of @c element_type
569 * @param __d A reference to a deleter.
570 *
571 * The deleter will be initialized with @p std::move(__d)
572 */
573 template<typename _Up, typename _Del = deleter_type,
574 typename = _Require<__safe_conversion_raw<_Up>,
575 is_move_constructible<_Del>>>
576 unique_ptr(_Up __p,
577 __enable_if_t<!is_lvalue_reference<_Del>::value,
578 _Del&&> __d) noexcept
579 : _M_t(std::move(__p), std::move(__d))
580 { }
581
582 template<typename _Up, typename _Del = deleter_type,
583 typename _DelUnref = typename remove_reference<_Del>::type,
584 typename = _Require<__safe_conversion_raw<_Up>>>
585 unique_ptr(_Up,
586 __enable_if_t<is_lvalue_reference<_Del>::value,
587 _DelUnref&&>) = delete;
588
589 /// Move constructor.
590 unique_ptr(unique_ptr&&) = default;
591
592 /// Creates a unique_ptr that owns nothing.
593 template<typename _Del = _Dp, typename = _DeleterConstraint<_Del>>
594 constexpr unique_ptr(nullptr_t) noexcept
595 : _M_t()
596 { }
597
598 template<typename _Up, typename _Ep, typename = _Require<
599 __safe_conversion_up<_Up, _Ep>,
600 typename conditional<is_reference<_Dp>::value,
601 is_same<_Ep, _Dp>,
602 is_convertible<_Ep, _Dp>>::type>>
603 unique_ptr(unique_ptr<_Up, _Ep>&& __u) noexcept
604 : _M_t(__u.release(), std::forward<_Ep>(__u.get_deleter()))
605 { }
606
607 /// Destructor, invokes the deleter if the stored pointer is not null.
608 ~unique_ptr()
609 {
610 auto& __ptr = _M_t._M_ptr();
611 if (__ptr != nullptr)
612 get_deleter()(__ptr);
613 __ptr = pointer();
614 }
615
616 // Assignment.
617
618 /** @brief Move assignment operator.
619 *
620 * Invokes the deleter if this object owns a pointer.
621 */
622 unique_ptr&
623 operator=(unique_ptr&&) = default;
624
625 /** @brief Assignment from another type.
626 *
627 * @param __u The object to transfer ownership from, which owns a
628 * convertible pointer to an array object.
629 *
630 * Invokes the deleter if this object owns a pointer.
631 */
632 template<typename _Up, typename _Ep>
633 typename
634 enable_if<__and_<__safe_conversion_up<_Up, _Ep>,
635 is_assignable<deleter_type&, _Ep&&>
636 >::value,
637 unique_ptr&>::type
638 operator=(unique_ptr<_Up, _Ep>&& __u) noexcept
639 {
640 reset(__u.release());
641 get_deleter() = std::forward<_Ep>(__u.get_deleter());
642 return *this;
643 }
644
645 /// Reset the %unique_ptr to empty, invoking the deleter if necessary.
646 unique_ptr&
647 operator=(nullptr_t) noexcept
648 {
649 reset();
650 return *this;
651 }
652
653 // Observers.
654
655 /// Access an element of owned array.
656 typename std::add_lvalue_reference<element_type>::type
657 operator[](size_t __i) const
658 {
659 __glibcxx_assert(get() != pointer());
660 return get()[__i];
661 }
662
663 /// Return the stored pointer.
664 pointer
665 get() const noexcept
666 { return _M_t._M_ptr(); }
667
668 /// Return a reference to the stored deleter.
669 deleter_type&
670 get_deleter() noexcept
671 { return _M_t._M_deleter(); }
672
673 /// Return a reference to the stored deleter.
674 const deleter_type&
675 get_deleter() const noexcept
676 { return _M_t._M_deleter(); }
677
678 /// Return @c true if the stored pointer is not null.
679 explicit operator bool() const noexcept
680 { return get() == pointer() ? false : true; }
681
682 // Modifiers.
683
684 /// Release ownership of any stored pointer.
685 pointer
686 release() noexcept
687 { return _M_t.release(); }
688
689 /** @brief Replace the stored pointer.
690 *
691 * @param __p The new pointer to store.
692 *
693 * The deleter will be invoked if a pointer is already owned.
694 */
695 template <typename _Up,
696 typename = _Require<
697 __or_<is_same<_Up, pointer>,
698 __and_<is_same<pointer, element_type*>,
699 is_pointer<_Up>,
700 is_convertible<
701 typename remove_pointer<_Up>::type(*)[],
702 element_type(*)[]
703 >
704 >
705 >
706 >>
707 void
708 reset(_Up __p) noexcept
709 { _M_t.reset(std::move(__p)); }
710
711 void reset(nullptr_t = nullptr) noexcept
712 { reset(pointer()); }
713
714 /// Exchange the pointer and deleter with another object.
715 void
716 swap(unique_ptr& __u) noexcept
717 {
718 static_assert(__is_swappable<_Dp>::value, "deleter must be swappable");
719 _M_t.swap(__u._M_t);
720 }
721
722 // Disable copy from lvalue.
723 unique_ptr(const unique_ptr&) = delete;
724 unique_ptr& operator=(const unique_ptr&) = delete;
725 };
726
727 /// @relates unique_ptr @{
728
729 /// Swap overload for unique_ptr
730 template<typename _Tp, typename _Dp>
731 inline
732#if __cplusplus201402L > 201402L || !defined(__STRICT_ANSI__1) // c++1z or gnu++11
733 // Constrained free swap overload, see p0185r1
734 typename enable_if<__is_swappable<_Dp>::value>::type
735#else
736 void
737#endif
738 swap(unique_ptr<_Tp, _Dp>& __x,
739 unique_ptr<_Tp, _Dp>& __y) noexcept
740 { __x.swap(__y); }
741
742#if __cplusplus201402L > 201402L || !defined(__STRICT_ANSI__1) // c++1z or gnu++11
743 template<typename _Tp, typename _Dp>
744 typename enable_if<!__is_swappable<_Dp>::value>::type
745 swap(unique_ptr<_Tp, _Dp>&,
746 unique_ptr<_Tp, _Dp>&) = delete;
747#endif
748
749 /// Equality operator for unique_ptr objects, compares the owned pointers
750 template<typename _Tp, typename _Dp,
751 typename _Up, typename _Ep>
752 _GLIBCXX_NODISCARD inline bool
753 operator==(const unique_ptr<_Tp, _Dp>& __x,
754 const unique_ptr<_Up, _Ep>& __y)
755 { return __x.get() == __y.get(); }
756
757 /// unique_ptr comparison with nullptr
758 template<typename _Tp, typename _Dp>
759 _GLIBCXX_NODISCARD inline bool
760 operator==(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
761 { return !__x; }
762
763#ifndef __cpp_lib_three_way_comparison
764 /// unique_ptr comparison with nullptr
765 template<typename _Tp, typename _Dp>
766 _GLIBCXX_NODISCARD inline bool
767 operator==(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
768 { return !__x; }
769
770 /// Inequality operator for unique_ptr objects, compares the owned pointers
771 template<typename _Tp, typename _Dp,
772 typename _Up, typename _Ep>
773 _GLIBCXX_NODISCARD inline bool
774 operator!=(const unique_ptr<_Tp, _Dp>& __x,
775 const unique_ptr<_Up, _Ep>& __y)
776 { return __x.get() != __y.get(); }
777
778 /// unique_ptr comparison with nullptr
779 template<typename _Tp, typename _Dp>
780 _GLIBCXX_NODISCARD inline bool
781 operator!=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t) noexcept
782 { return (bool)__x; }
783
784 /// unique_ptr comparison with nullptr
785 template<typename _Tp, typename _Dp>
786 _GLIBCXX_NODISCARD inline bool
787 operator!=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x) noexcept
788 { return (bool)__x; }
789#endif // three way comparison
790
791 /// Relational operator for unique_ptr objects, compares the owned pointers
792 template<typename _Tp, typename _Dp,
793 typename _Up, typename _Ep>
794 _GLIBCXX_NODISCARD inline bool
795 operator<(const unique_ptr<_Tp, _Dp>& __x,
796 const unique_ptr<_Up, _Ep>& __y)
797 {
798 typedef typename
799 std::common_type<typename unique_ptr<_Tp, _Dp>::pointer,
800 typename unique_ptr<_Up, _Ep>::pointer>::type _CT;
801 return std::less<_CT>()(__x.get(), __y.get());
802 }
803
804 /// unique_ptr comparison with nullptr
805 template<typename _Tp, typename _Dp>
806 _GLIBCXX_NODISCARD inline bool
807 operator<(const unique_ptr<_Tp, _Dp>& __x, nullptr_t)
808 {
809 return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(__x.get(),
810 nullptr);
811 }
812
813 /// unique_ptr comparison with nullptr
814 template<typename _Tp, typename _Dp>
815 _GLIBCXX_NODISCARD inline bool
816 operator<(nullptr_t, const unique_ptr<_Tp, _Dp>& __x)
817 {
818 return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(nullptr,
819 __x.get());
820 }
821
822 /// Relational operator for unique_ptr objects, compares the owned pointers
823 template<typename _Tp, typename _Dp,
824 typename _Up, typename _Ep>
825 _GLIBCXX_NODISCARD inline bool
826 operator<=(const unique_ptr<_Tp, _Dp>& __x,
827 const unique_ptr<_Up, _Ep>& __y)
828 { return !(__y < __x); }
829
830 /// unique_ptr comparison with nullptr
831 template<typename _Tp, typename _Dp>
832 _GLIBCXX_NODISCARD inline bool
833 operator<=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t)
834 { return !(nullptr < __x); }
835
836 /// unique_ptr comparison with nullptr
837 template<typename _Tp, typename _Dp>
838 _GLIBCXX_NODISCARD inline bool
839 operator<=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x)
840 { return !(__x < nullptr); }
841
842 /// Relational operator for unique_ptr objects, compares the owned pointers
843 template<typename _Tp, typename _Dp,
844 typename _Up, typename _Ep>
845 _GLIBCXX_NODISCARD inline bool
846 operator>(const unique_ptr<_Tp, _Dp>& __x,
847 const unique_ptr<_Up, _Ep>& __y)
848 { return (__y < __x); }
849
850 /// unique_ptr comparison with nullptr
851 template<typename _Tp, typename _Dp>
852 _GLIBCXX_NODISCARD inline bool
853 operator>(const unique_ptr<_Tp, _Dp>& __x, nullptr_t)
854 {
855 return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(nullptr,
856 __x.get());
857 }
858
859 /// unique_ptr comparison with nullptr
860 template<typename _Tp, typename _Dp>
861 _GLIBCXX_NODISCARD inline bool
862 operator>(nullptr_t, const unique_ptr<_Tp, _Dp>& __x)
863 {
864 return std::less<typename unique_ptr<_Tp, _Dp>::pointer>()(__x.get(),
865 nullptr);
866 }
867
868 /// Relational operator for unique_ptr objects, compares the owned pointers
869 template<typename _Tp, typename _Dp,
870 typename _Up, typename _Ep>
871 _GLIBCXX_NODISCARD inline bool
872 operator>=(const unique_ptr<_Tp, _Dp>& __x,
873 const unique_ptr<_Up, _Ep>& __y)
874 { return !(__x < __y); }
875
876 /// unique_ptr comparison with nullptr
877 template<typename _Tp, typename _Dp>
878 _GLIBCXX_NODISCARD inline bool
879 operator>=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t)
880 { return !(__x < nullptr); }
881
882 /// unique_ptr comparison with nullptr
883 template<typename _Tp, typename _Dp>
884 _GLIBCXX_NODISCARD inline bool
885 operator>=(nullptr_t, const unique_ptr<_Tp, _Dp>& __x)
886 { return !(nullptr < __x); }
887
888#ifdef __cpp_lib_three_way_comparison
889 template<typename _Tp, typename _Dp, typename _Up, typename _Ep>
890 requires three_way_comparable_with<typename unique_ptr<_Tp, _Dp>::pointer,
891 typename unique_ptr<_Up, _Ep>::pointer>
892 inline
893 compare_three_way_result_t<typename unique_ptr<_Tp, _Dp>::pointer,
894 typename unique_ptr<_Up, _Ep>::pointer>
895 operator<=>(const unique_ptr<_Tp, _Dp>& __x,
896 const unique_ptr<_Up, _Ep>& __y)
897 { return compare_three_way()(__x.get(), __y.get()); }
898
899 template<typename _Tp, typename _Dp>
900 requires three_way_comparable<typename unique_ptr<_Tp, _Dp>::pointer>
901 inline
902 compare_three_way_result_t<typename unique_ptr<_Tp, _Dp>::pointer>
903 operator<=>(const unique_ptr<_Tp, _Dp>& __x, nullptr_t)
904 {
905 using pointer = typename unique_ptr<_Tp, _Dp>::pointer;
906 return compare_three_way()(__x.get(), static_cast<pointer>(nullptr));
907 }
908#endif
909 // @} relates unique_ptr
910
911 /// @cond undocumented
912 template<typename _Up, typename _Ptr = typename _Up::pointer,
913 bool = __poison_hash<_Ptr>::__enable_hash_call>
914 struct __uniq_ptr_hash
915#if ! _GLIBCXX_INLINE_VERSION0
916 : private __poison_hash<_Ptr>
917#endif
918 {
919 size_t
920 operator()(const _Up& __u) const
921 noexcept(noexcept(std::declval<hash<_Ptr>>()(std::declval<_Ptr>())))
922 { return hash<_Ptr>()(__u.get()); }
923 };
924
925 template<typename _Up, typename _Ptr>
926 struct __uniq_ptr_hash<_Up, _Ptr, false>
927 : private __poison_hash<_Ptr>
928 { };
929 /// @endcond
930
931 /// std::hash specialization for unique_ptr.
932 template<typename _Tp, typename _Dp>
933 struct hash<unique_ptr<_Tp, _Dp>>
934 : public __hash_base<size_t, unique_ptr<_Tp, _Dp>>,
935 public __uniq_ptr_hash<unique_ptr<_Tp, _Dp>>
936 { };
937
938#if __cplusplus201402L >= 201402L
939 /// @relates unique_ptr @{
940#define __cpp_lib_make_unique201304 201304
941
942 /// @cond undocumented
943
944 template<typename _Tp>
945 struct _MakeUniq
946 { typedef unique_ptr<_Tp> __single_object; };
947
948 template<typename _Tp>
949 struct _MakeUniq<_Tp[]>
950 { typedef unique_ptr<_Tp[]> __array; };
951
952 template<typename _Tp, size_t _Bound>
953 struct _MakeUniq<_Tp[_Bound]>
954 { struct __invalid_type { }; };
955
956 /// @endcond
957
958 /// std::make_unique for single objects
959 template<typename _Tp, typename... _Args>
960 inline typename _MakeUniq<_Tp>::__single_object
961 make_unique(_Args&&... __args)
962 { return unique_ptr<_Tp>(new _Tp(std::forward<_Args>(__args)...)); }
3
Calling constructor for 'LoopNest'
963
964 /// std::make_unique for arrays of unknown bound
965 template<typename _Tp>
966 inline typename _MakeUniq<_Tp>::__array
967 make_unique(size_t __num)
968 { return unique_ptr<_Tp>(new remove_extent_t<_Tp>[__num]()); }
969
970 /// Disable std::make_unique for arrays of known bound
971 template<typename _Tp, typename... _Args>
972 inline typename _MakeUniq<_Tp>::__invalid_type
973 make_unique(_Args&&...) = delete;
974 // @} relates unique_ptr
975#endif // C++14
976
977#if __cplusplus201402L > 201703L && __cpp_concepts
978 // _GLIBCXX_RESOLVE_LIB_DEFECTS
979 // 2948. unique_ptr does not define operator<< for stream output
980 /// Stream output operator for unique_ptr
981 template<typename _CharT, typename _Traits, typename _Tp, typename _Dp>
982 inline basic_ostream<_CharT, _Traits>&
983 operator<<(basic_ostream<_CharT, _Traits>& __os,
984 const unique_ptr<_Tp, _Dp>& __p)
985 requires requires { __os << __p.get(); }
986 {
987 __os << __p.get();
988 return __os;
989 }
990#endif // C++20
991
992 // @} group pointer_abstractions
993
994#if __cplusplus201402L >= 201703L
995 namespace __detail::__variant
996 {
997 template<typename> struct _Never_valueless_alt; // see <variant>
998
999 // Provide the strong exception-safety guarantee when emplacing a
1000 // unique_ptr into a variant.
1001 template<typename _Tp, typename _Del>
1002 struct _Never_valueless_alt<std::unique_ptr<_Tp, _Del>>
1003 : std::true_type
1004 { };
1005 } // namespace __detail::__variant
1006#endif // C++17
1007
1008_GLIBCXX_END_NAMESPACE_VERSION
1009} // namespace
1010
1011#endif /* _UNIQUE_PTR_H */