File: | build/source/clang/include/clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h |
Warning: | line 292, column 9 Potential memory leak |
Press '?' to see keyboard shortcuts
Keyboard shortcuts:
1 | //=== ErrnoModeling.cpp -----------------------------------------*- C++ -*-===// | |||
2 | // | |||
3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. | |||
4 | // See https://llvm.org/LICENSE.txt for license information. | |||
5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception | |||
6 | // | |||
7 | //===----------------------------------------------------------------------===// | |||
8 | // | |||
9 | // This defines a checker `ErrnoModeling`, which is used to make the system | |||
10 | // value 'errno' available to other checkers. | |||
11 | // The 'errno' value is stored at a special memory region that is accessible | |||
12 | // through the `errno_modeling` namespace. The memory region is either the | |||
13 | // region of `errno` itself if it is a variable, otherwise an artifically | |||
14 | // created region (in the system memory space). If `errno` is defined by using | |||
15 | // a function which returns the address of it (this is always the case if it is | |||
16 | // not a variable) this function is recognized and evaluated. In this way | |||
17 | // `errno` becomes visible to the analysis and checkers can change its value. | |||
18 | // | |||
19 | //===----------------------------------------------------------------------===// | |||
20 | ||||
21 | #include "ErrnoModeling.h" | |||
22 | #include "clang/AST/ParentMapContext.h" | |||
23 | #include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h" | |||
24 | #include "clang/StaticAnalyzer/Core/Checker.h" | |||
25 | #include "clang/StaticAnalyzer/Core/CheckerManager.h" | |||
26 | #include "clang/StaticAnalyzer/Core/PathSensitive/CallDescription.h" | |||
27 | #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h" | |||
28 | #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h" | |||
29 | #include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h" | |||
30 | #include "llvm/ADT/STLExtras.h" | |||
31 | #include <optional> | |||
32 | ||||
33 | using namespace clang; | |||
34 | using namespace ento; | |||
35 | ||||
36 | namespace { | |||
37 | ||||
38 | // Name of the "errno" variable. | |||
39 | // FIXME: Is there a system where it is not called "errno" but is a variable? | |||
40 | const char *ErrnoVarName = "errno"; | |||
41 | // Names of functions that return a location of the "errno" value. | |||
42 | // FIXME: Are there other similar function names? | |||
43 | const char *ErrnoLocationFuncNames[] = {"__errno_location", "___errno", | |||
44 | "__errno", "_errno", "__error"}; | |||
45 | ||||
46 | class ErrnoModeling | |||
47 | : public Checker<check::ASTDecl<TranslationUnitDecl>, check::BeginFunction, | |||
48 | check::LiveSymbols, eval::Call> { | |||
49 | public: | |||
50 | void checkASTDecl(const TranslationUnitDecl *D, AnalysisManager &Mgr, | |||
51 | BugReporter &BR) const; | |||
52 | void checkBeginFunction(CheckerContext &C) const; | |||
53 | void checkLiveSymbols(ProgramStateRef State, SymbolReaper &SR) const; | |||
54 | bool evalCall(const CallEvent &Call, CheckerContext &C) const; | |||
55 | ||||
56 | // The declaration of an "errno" variable or "errno location" function. | |||
57 | mutable const Decl *ErrnoDecl = nullptr; | |||
58 | ||||
59 | private: | |||
60 | // FIXME: Names from `ErrnoLocationFuncNames` are used to build this set. | |||
61 | CallDescriptionSet ErrnoLocationCalls{{{"__errno_location"}, 0, 0}, | |||
62 | {{"___errno"}, 0, 0}, | |||
63 | {{"__errno"}, 0, 0}, | |||
64 | {{"_errno"}, 0, 0}, | |||
65 | {{"__error"}, 0, 0}}; | |||
66 | }; | |||
67 | ||||
68 | } // namespace | |||
69 | ||||
70 | /// Store a MemRegion that contains the 'errno' integer value. | |||
71 | /// The value is null if the 'errno' value was not recognized in the AST. | |||
72 | REGISTER_TRAIT_WITH_PROGRAMSTATE(ErrnoRegion, const MemRegion *)namespace { class ErrnoRegion {}; using ErrnoRegionTy = const MemRegion *; } namespace clang { namespace ento { template < > struct ProgramStateTrait<ErrnoRegion> : public ProgramStatePartialTrait <ErrnoRegionTy> { static void *GDMIndex() { static int Index ; return &Index; } }; } } | |||
73 | ||||
74 | REGISTER_TRAIT_WITH_PROGRAMSTATE(ErrnoState, errno_modeling::ErrnoCheckState)namespace { class ErrnoState {}; using ErrnoStateTy = errno_modeling ::ErrnoCheckState; } namespace clang { namespace ento { template <> struct ProgramStateTrait<ErrnoState> : public ProgramStatePartialTrait<ErrnoStateTy> { static void * GDMIndex() { static int Index; return &Index; } }; } } | |||
75 | ||||
76 | /// Search for a variable called "errno" in the AST. | |||
77 | /// Return nullptr if not found. | |||
78 | static const VarDecl *getErrnoVar(ASTContext &ACtx) { | |||
79 | IdentifierInfo &II = ACtx.Idents.get(ErrnoVarName); | |||
80 | auto LookupRes = ACtx.getTranslationUnitDecl()->lookup(&II); | |||
81 | auto Found = llvm::find_if(LookupRes, [&ACtx](const Decl *D) { | |||
82 | if (auto *VD = dyn_cast<VarDecl>(D)) | |||
83 | return ACtx.getSourceManager().isInSystemHeader(VD->getLocation()) && | |||
84 | VD->hasExternalStorage() && | |||
85 | VD->getType().getCanonicalType() == ACtx.IntTy; | |||
86 | return false; | |||
87 | }); | |||
88 | if (Found == LookupRes.end()) | |||
89 | return nullptr; | |||
90 | ||||
91 | return cast<VarDecl>(*Found); | |||
92 | } | |||
93 | ||||
94 | /// Search for a function with a specific name that is used to return a pointer | |||
95 | /// to "errno". | |||
96 | /// Return nullptr if no such function was found. | |||
97 | static const FunctionDecl *getErrnoFunc(ASTContext &ACtx) { | |||
98 | SmallVector<const Decl *> LookupRes; | |||
99 | for (StringRef ErrnoName : ErrnoLocationFuncNames) { | |||
100 | IdentifierInfo &II = ACtx.Idents.get(ErrnoName); | |||
101 | llvm::append_range(LookupRes, ACtx.getTranslationUnitDecl()->lookup(&II)); | |||
102 | } | |||
103 | ||||
104 | auto Found = llvm::find_if(LookupRes, [&ACtx](const Decl *D) { | |||
105 | if (auto *FD = dyn_cast<FunctionDecl>(D)) | |||
106 | return ACtx.getSourceManager().isInSystemHeader(FD->getLocation()) && | |||
107 | FD->isExternC() && FD->getNumParams() == 0 && | |||
108 | FD->getReturnType().getCanonicalType() == | |||
109 | ACtx.getPointerType(ACtx.IntTy); | |||
110 | return false; | |||
111 | }); | |||
112 | if (Found == LookupRes.end()) | |||
113 | return nullptr; | |||
114 | ||||
115 | return cast<FunctionDecl>(*Found); | |||
116 | } | |||
117 | ||||
118 | void ErrnoModeling::checkASTDecl(const TranslationUnitDecl *D, | |||
119 | AnalysisManager &Mgr, BugReporter &BR) const { | |||
120 | // Try to find an usable `errno` value. | |||
121 | // It can be an external variable called "errno" or a function that returns a | |||
122 | // pointer to the "errno" value. This function can have different names. | |||
123 | // The actual case is dependent on the C library implementation, we | |||
124 | // can only search for a match in one of these variations. | |||
125 | // We assume that exactly one of these cases might be true. | |||
126 | ErrnoDecl = getErrnoVar(Mgr.getASTContext()); | |||
127 | if (!ErrnoDecl) | |||
128 | ErrnoDecl = getErrnoFunc(Mgr.getASTContext()); | |||
129 | } | |||
130 | ||||
131 | void ErrnoModeling::checkBeginFunction(CheckerContext &C) const { | |||
132 | if (!C.inTopFrame()) | |||
133 | return; | |||
134 | ||||
135 | ASTContext &ACtx = C.getASTContext(); | |||
136 | ProgramStateRef State = C.getState(); | |||
137 | ||||
138 | if (const auto *ErrnoVar = dyn_cast_or_null<VarDecl>(ErrnoDecl)) { | |||
139 | // There is an external 'errno' variable. | |||
140 | // Use its memory region. | |||
141 | // The memory region for an 'errno'-like variable is allocated in system | |||
142 | // space by MemRegionManager. | |||
143 | const MemRegion *ErrnoR = | |||
144 | State->getRegion(ErrnoVar, C.getLocationContext()); | |||
145 | assert(ErrnoR && "Memory region should exist for the 'errno' variable.")(static_cast <bool> (ErrnoR && "Memory region should exist for the 'errno' variable." ) ? void (0) : __assert_fail ("ErrnoR && \"Memory region should exist for the 'errno' variable.\"" , "clang/lib/StaticAnalyzer/Checkers/ErrnoModeling.cpp", 145, __extension__ __PRETTY_FUNCTION__)); | |||
146 | State = State->set<ErrnoRegion>(ErrnoR); | |||
147 | State = | |||
148 | errno_modeling::setErrnoValue(State, C, 0, errno_modeling::Irrelevant); | |||
149 | C.addTransition(State); | |||
150 | } else if (ErrnoDecl) { | |||
151 | assert(isa<FunctionDecl>(ErrnoDecl) && "Invalid errno location function.")(static_cast <bool> (isa<FunctionDecl>(ErrnoDecl) && "Invalid errno location function.") ? void (0) : __assert_fail ("isa<FunctionDecl>(ErrnoDecl) && \"Invalid errno location function.\"" , "clang/lib/StaticAnalyzer/Checkers/ErrnoModeling.cpp", 151, __extension__ __PRETTY_FUNCTION__)); | |||
152 | // There is a function that returns the location of 'errno'. | |||
153 | // We must create a memory region for it in system space. | |||
154 | // Currently a symbolic region is used with an artifical symbol. | |||
155 | // FIXME: It is better to have a custom (new) kind of MemRegion for such | |||
156 | // cases. | |||
157 | SValBuilder &SVB = C.getSValBuilder(); | |||
158 | MemRegionManager &RMgr = C.getStateManager().getRegionManager(); | |||
159 | ||||
160 | const MemSpaceRegion *GlobalSystemSpace = | |||
161 | RMgr.getGlobalsRegion(MemRegion::GlobalSystemSpaceRegionKind); | |||
162 | ||||
163 | // Create an artifical symbol for the region. | |||
164 | // It is not possible to associate a statement or expression in this case. | |||
165 | const SymbolConjured *Sym = SVB.conjureSymbol( | |||
166 | nullptr, C.getLocationContext(), | |||
167 | ACtx.getLValueReferenceType(ACtx.IntTy), C.blockCount(), &ErrnoDecl); | |||
168 | ||||
169 | // The symbolic region is untyped, create a typed sub-region in it. | |||
170 | // The ElementRegion is used to make the errno region a typed region. | |||
171 | const MemRegion *ErrnoR = RMgr.getElementRegion( | |||
172 | ACtx.IntTy, SVB.makeZeroArrayIndex(), | |||
173 | RMgr.getSymbolicRegion(Sym, GlobalSystemSpace), C.getASTContext()); | |||
174 | State = State->set<ErrnoRegion>(ErrnoR); | |||
175 | State = | |||
176 | errno_modeling::setErrnoValue(State, C, 0, errno_modeling::Irrelevant); | |||
177 | C.addTransition(State); | |||
178 | } | |||
179 | } | |||
180 | ||||
181 | bool ErrnoModeling::evalCall(const CallEvent &Call, CheckerContext &C) const { | |||
182 | // Return location of "errno" at a call to an "errno address returning" | |||
183 | // function. | |||
184 | if (ErrnoLocationCalls.contains(Call)) { | |||
185 | ProgramStateRef State = C.getState(); | |||
186 | ||||
187 | const MemRegion *ErrnoR = State->get<ErrnoRegion>(); | |||
188 | if (!ErrnoR) | |||
189 | return false; | |||
190 | ||||
191 | State = State->BindExpr(Call.getOriginExpr(), C.getLocationContext(), | |||
192 | loc::MemRegionVal{ErrnoR}); | |||
193 | C.addTransition(State); | |||
194 | return true; | |||
195 | } | |||
196 | ||||
197 | return false; | |||
198 | } | |||
199 | ||||
200 | void ErrnoModeling::checkLiveSymbols(ProgramStateRef State, | |||
201 | SymbolReaper &SR) const { | |||
202 | // The special errno region should never garbage collected. | |||
203 | if (const auto *ErrnoR = State->get<ErrnoRegion>()) | |||
204 | SR.markLive(ErrnoR); | |||
205 | } | |||
206 | ||||
207 | namespace clang { | |||
208 | namespace ento { | |||
209 | namespace errno_modeling { | |||
210 | ||||
211 | std::optional<SVal> getErrnoValue(ProgramStateRef State) { | |||
212 | const MemRegion *ErrnoR = State->get<ErrnoRegion>(); | |||
213 | if (!ErrnoR) | |||
214 | return {}; | |||
215 | QualType IntTy = State->getAnalysisManager().getASTContext().IntTy; | |||
216 | return State->getSVal(ErrnoR, IntTy); | |||
217 | } | |||
218 | ||||
219 | ProgramStateRef setErrnoValue(ProgramStateRef State, | |||
220 | const LocationContext *LCtx, SVal Value, | |||
221 | ErrnoCheckState EState) { | |||
222 | const MemRegion *ErrnoR = State->get<ErrnoRegion>(); | |||
223 | if (!ErrnoR) | |||
224 | return State; | |||
225 | // First set the errno value, the old state is still available at 'checkBind' | |||
226 | // or 'checkLocation' for errno value. | |||
227 | State = State->bindLoc(loc::MemRegionVal{ErrnoR}, Value, LCtx); | |||
228 | return State->set<ErrnoState>(EState); | |||
229 | } | |||
230 | ||||
231 | ProgramStateRef setErrnoValue(ProgramStateRef State, CheckerContext &C, | |||
232 | uint64_t Value, ErrnoCheckState EState) { | |||
233 | const MemRegion *ErrnoR = State->get<ErrnoRegion>(); | |||
234 | if (!ErrnoR) | |||
235 | return State; | |||
236 | State = State->bindLoc( | |||
237 | loc::MemRegionVal{ErrnoR}, | |||
238 | C.getSValBuilder().makeIntVal(Value, C.getASTContext().IntTy), | |||
239 | C.getLocationContext()); | |||
240 | return State->set<ErrnoState>(EState); | |||
241 | } | |||
242 | ||||
243 | std::optional<Loc> getErrnoLoc(ProgramStateRef State) { | |||
244 | const MemRegion *ErrnoR = State->get<ErrnoRegion>(); | |||
245 | if (!ErrnoR) | |||
246 | return {}; | |||
247 | return loc::MemRegionVal{ErrnoR}; | |||
248 | } | |||
249 | ||||
250 | ErrnoCheckState getErrnoState(ProgramStateRef State) { | |||
251 | return State->get<ErrnoState>(); | |||
252 | } | |||
253 | ||||
254 | ProgramStateRef setErrnoState(ProgramStateRef State, ErrnoCheckState EState) { | |||
255 | return State->set<ErrnoState>(EState); | |||
256 | } | |||
257 | ||||
258 | ProgramStateRef clearErrnoState(ProgramStateRef State) { | |||
259 | return setErrnoState(State, Irrelevant); | |||
260 | } | |||
261 | ||||
262 | bool isErrno(const Decl *D) { | |||
263 | if (const auto *VD = dyn_cast_or_null<VarDecl>(D)) | |||
264 | if (const IdentifierInfo *II = VD->getIdentifier()) | |||
265 | return II->getName() == ErrnoVarName; | |||
266 | if (const auto *FD = dyn_cast_or_null<FunctionDecl>(D)) | |||
267 | if (const IdentifierInfo *II = FD->getIdentifier()) | |||
268 | return llvm::is_contained(ErrnoLocationFuncNames, II->getName()); | |||
269 | return false; | |||
270 | } | |||
271 | ||||
272 | const char *describeErrnoCheckState(ErrnoCheckState CS) { | |||
273 | assert(CS == errno_modeling::MustNotBeChecked &&(static_cast <bool> (CS == errno_modeling::MustNotBeChecked && "Errno description not applicable.") ? void (0) : __assert_fail ("CS == errno_modeling::MustNotBeChecked && \"Errno description not applicable.\"" , "clang/lib/StaticAnalyzer/Checkers/ErrnoModeling.cpp", 274, __extension__ __PRETTY_FUNCTION__)) | |||
274 | "Errno description not applicable.")(static_cast <bool> (CS == errno_modeling::MustNotBeChecked && "Errno description not applicable.") ? void (0) : __assert_fail ("CS == errno_modeling::MustNotBeChecked && \"Errno description not applicable.\"" , "clang/lib/StaticAnalyzer/Checkers/ErrnoModeling.cpp", 274, __extension__ __PRETTY_FUNCTION__)); | |||
275 | return "may be undefined after the call and should not be used"; | |||
276 | } | |||
277 | ||||
278 | const NoteTag *getErrnoNoteTag(CheckerContext &C, const std::string &Message) { | |||
279 | return C.getNoteTag([Message](PathSensitiveBugReport &BR) -> std::string { | |||
280 | const MemRegion *ErrnoR = BR.getErrorNode()->getState()->get<ErrnoRegion>(); | |||
281 | if (ErrnoR && BR.isInteresting(ErrnoR)) { | |||
282 | BR.markNotInteresting(ErrnoR); | |||
283 | return Message; | |||
284 | } | |||
285 | return ""; | |||
286 | }); | |||
287 | } | |||
288 | ||||
289 | ProgramStateRef setErrnoForStdSuccess(ProgramStateRef State, | |||
290 | CheckerContext &C) { | |||
291 | return setErrnoState(State, MustNotBeChecked); | |||
292 | } | |||
293 | ||||
294 | ProgramStateRef setErrnoForStdFailure(ProgramStateRef State, CheckerContext &C, | |||
295 | NonLoc ErrnoSym) { | |||
296 | SValBuilder &SVB = C.getSValBuilder(); | |||
297 | NonLoc ZeroVal = SVB.makeZeroVal(C.getASTContext().IntTy).castAs<NonLoc>(); | |||
298 | DefinedOrUnknownSVal Cond = | |||
299 | SVB.evalBinOp(State, BO_NE, ErrnoSym, ZeroVal, SVB.getConditionType()) | |||
300 | .castAs<DefinedOrUnknownSVal>(); | |||
301 | State = State->assume(Cond, true); | |||
302 | if (!State) | |||
303 | return nullptr; | |||
304 | return setErrnoValue(State, C.getLocationContext(), ErrnoSym, Irrelevant); | |||
305 | } | |||
306 | ||||
307 | ProgramStateRef setErrnoStdMustBeChecked(ProgramStateRef State, | |||
308 | CheckerContext &C, | |||
309 | const Expr *InvalE) { | |||
310 | const MemRegion *ErrnoR = State->get<ErrnoRegion>(); | |||
311 | if (!ErrnoR) | |||
312 | return State; | |||
313 | State = State->invalidateRegions(ErrnoR, InvalE, C.blockCount(), | |||
314 | C.getLocationContext(), false); | |||
315 | if (!State) | |||
316 | return nullptr; | |||
317 | return setErrnoState(State, MustBeChecked); | |||
318 | } | |||
319 | ||||
320 | const NoteTag *getNoteTagForStdSuccess(CheckerContext &C, llvm::StringRef Fn) { | |||
321 | return getErrnoNoteTag( | |||
| ||||
322 | C, (Twine("Assuming that function '") + Twine(Fn) + | |||
323 | Twine("' is successful, in this case the value 'errno' ") + | |||
324 | Twine(describeErrnoCheckState(MustNotBeChecked))) | |||
325 | .str()); | |||
326 | } | |||
327 | ||||
328 | const NoteTag *getNoteTagForStdMustBeChecked(CheckerContext &C, | |||
329 | llvm::StringRef Fn) { | |||
330 | return getErrnoNoteTag( | |||
331 | C, (Twine("Function '") + Twine(Fn) + | |||
332 | Twine("' indicates failure only by setting of 'errno'")) | |||
333 | .str()); | |||
334 | } | |||
335 | ||||
336 | } // namespace errno_modeling | |||
337 | } // namespace ento | |||
338 | } // namespace clang | |||
339 | ||||
340 | void ento::registerErrnoModeling(CheckerManager &mgr) { | |||
341 | mgr.registerChecker<ErrnoModeling>(); | |||
342 | } | |||
343 | ||||
344 | bool ento::shouldRegisterErrnoModeling(const CheckerManager &mgr) { | |||
345 | return true; | |||
346 | } |
1 | //== CheckerContext.h - Context info for path-sensitive checkers--*- C++ -*--=// | |||
2 | // | |||
3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. | |||
4 | // See https://llvm.org/LICENSE.txt for license information. | |||
5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception | |||
6 | // | |||
7 | //===----------------------------------------------------------------------===// | |||
8 | // | |||
9 | // This file defines CheckerContext that provides contextual info for | |||
10 | // path-sensitive checkers. | |||
11 | // | |||
12 | //===----------------------------------------------------------------------===// | |||
13 | ||||
14 | #ifndef LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_CHECKERCONTEXT_H | |||
15 | #define LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_CHECKERCONTEXT_H | |||
16 | ||||
17 | #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h" | |||
18 | #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h" | |||
19 | #include <optional> | |||
20 | ||||
21 | namespace clang { | |||
22 | namespace ento { | |||
23 | ||||
24 | class CheckerContext { | |||
25 | ExprEngine &Eng; | |||
26 | /// The current exploded(symbolic execution) graph node. | |||
27 | ExplodedNode *Pred; | |||
28 | /// The flag is true if the (state of the execution) has been modified | |||
29 | /// by the checker using this context. For example, a new transition has been | |||
30 | /// added or a bug report issued. | |||
31 | bool Changed; | |||
32 | /// The tagged location, which is used to generate all new nodes. | |||
33 | const ProgramPoint Location; | |||
34 | NodeBuilder &NB; | |||
35 | ||||
36 | public: | |||
37 | /// If we are post visiting a call, this flag will be set if the | |||
38 | /// call was inlined. In all other cases it will be false. | |||
39 | const bool wasInlined; | |||
40 | ||||
41 | CheckerContext(NodeBuilder &builder, | |||
42 | ExprEngine &eng, | |||
43 | ExplodedNode *pred, | |||
44 | const ProgramPoint &loc, | |||
45 | bool wasInlined = false) | |||
46 | : Eng(eng), | |||
47 | Pred(pred), | |||
48 | Changed(false), | |||
49 | Location(loc), | |||
50 | NB(builder), | |||
51 | wasInlined(wasInlined) { | |||
52 | assert(Pred->getState() &&(static_cast <bool> (Pred->getState() && "We should not call the checkers on an empty state." ) ? void (0) : __assert_fail ("Pred->getState() && \"We should not call the checkers on an empty state.\"" , "clang/include/clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h" , 53, __extension__ __PRETTY_FUNCTION__)) | |||
53 | "We should not call the checkers on an empty state.")(static_cast <bool> (Pred->getState() && "We should not call the checkers on an empty state." ) ? void (0) : __assert_fail ("Pred->getState() && \"We should not call the checkers on an empty state.\"" , "clang/include/clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h" , 53, __extension__ __PRETTY_FUNCTION__)); | |||
54 | } | |||
55 | ||||
56 | AnalysisManager &getAnalysisManager() { | |||
57 | return Eng.getAnalysisManager(); | |||
58 | } | |||
59 | ||||
60 | ConstraintManager &getConstraintManager() { | |||
61 | return Eng.getConstraintManager(); | |||
62 | } | |||
63 | ||||
64 | StoreManager &getStoreManager() { | |||
65 | return Eng.getStoreManager(); | |||
66 | } | |||
67 | ||||
68 | /// Returns the previous node in the exploded graph, which includes | |||
69 | /// the state of the program before the checker ran. Note, checkers should | |||
70 | /// not retain the node in their state since the nodes might get invalidated. | |||
71 | ExplodedNode *getPredecessor() { return Pred; } | |||
72 | const ProgramStateRef &getState() const { return Pred->getState(); } | |||
73 | ||||
74 | /// Check if the checker changed the state of the execution; ex: added | |||
75 | /// a new transition or a bug report. | |||
76 | bool isDifferent() { return Changed; } | |||
77 | ||||
78 | /// Returns the number of times the current block has been visited | |||
79 | /// along the analyzed path. | |||
80 | unsigned blockCount() const { | |||
81 | return NB.getContext().blockCount(); | |||
82 | } | |||
83 | ||||
84 | ASTContext &getASTContext() { | |||
85 | return Eng.getContext(); | |||
86 | } | |||
87 | ||||
88 | const ASTContext &getASTContext() const { return Eng.getContext(); } | |||
89 | ||||
90 | const LangOptions &getLangOpts() const { | |||
91 | return Eng.getContext().getLangOpts(); | |||
92 | } | |||
93 | ||||
94 | const LocationContext *getLocationContext() const { | |||
95 | return Pred->getLocationContext(); | |||
96 | } | |||
97 | ||||
98 | const StackFrameContext *getStackFrame() const { | |||
99 | return Pred->getStackFrame(); | |||
100 | } | |||
101 | ||||
102 | /// Return true if the current LocationContext has no caller context. | |||
103 | bool inTopFrame() const { return getLocationContext()->inTopFrame(); } | |||
104 | ||||
105 | BugReporter &getBugReporter() { | |||
106 | return Eng.getBugReporter(); | |||
107 | } | |||
108 | ||||
109 | const SourceManager &getSourceManager() { | |||
110 | return getBugReporter().getSourceManager(); | |||
111 | } | |||
112 | ||||
113 | Preprocessor &getPreprocessor() { return getBugReporter().getPreprocessor(); } | |||
114 | ||||
115 | SValBuilder &getSValBuilder() { | |||
116 | return Eng.getSValBuilder(); | |||
117 | } | |||
118 | ||||
119 | SymbolManager &getSymbolManager() { | |||
120 | return getSValBuilder().getSymbolManager(); | |||
121 | } | |||
122 | ||||
123 | ProgramStateManager &getStateManager() { | |||
124 | return Eng.getStateManager(); | |||
125 | } | |||
126 | ||||
127 | AnalysisDeclContext *getCurrentAnalysisDeclContext() const { | |||
128 | return Pred->getLocationContext()->getAnalysisDeclContext(); | |||
129 | } | |||
130 | ||||
131 | /// Get the blockID. | |||
132 | unsigned getBlockID() const { | |||
133 | return NB.getContext().getBlock()->getBlockID(); | |||
134 | } | |||
135 | ||||
136 | /// If the given node corresponds to a PostStore program point, | |||
137 | /// retrieve the location region as it was uttered in the code. | |||
138 | /// | |||
139 | /// This utility can be useful for generating extensive diagnostics, for | |||
140 | /// example, for finding variables that the given symbol was assigned to. | |||
141 | static const MemRegion *getLocationRegionIfPostStore(const ExplodedNode *N) { | |||
142 | ProgramPoint L = N->getLocation(); | |||
143 | if (std::optional<PostStore> PSL = L.getAs<PostStore>()) | |||
144 | return reinterpret_cast<const MemRegion*>(PSL->getLocationValue()); | |||
145 | return nullptr; | |||
146 | } | |||
147 | ||||
148 | /// Get the value of arbitrary expressions at this point in the path. | |||
149 | SVal getSVal(const Stmt *S) const { | |||
150 | return Pred->getSVal(S); | |||
151 | } | |||
152 | ||||
153 | /// Returns true if the value of \p E is greater than or equal to \p | |||
154 | /// Val under unsigned comparison | |||
155 | bool isGreaterOrEqual(const Expr *E, unsigned long long Val); | |||
156 | ||||
157 | /// Returns true if the value of \p E is negative. | |||
158 | bool isNegative(const Expr *E); | |||
159 | ||||
160 | /// Generates a new transition in the program state graph | |||
161 | /// (ExplodedGraph). Uses the default CheckerContext predecessor node. | |||
162 | /// | |||
163 | /// @param State The state of the generated node. If not specified, the state | |||
164 | /// will not be changed, but the new node will have the checker's tag. | |||
165 | /// @param Tag The tag is used to uniquely identify the creation site. If no | |||
166 | /// tag is specified, a default tag, unique to the given checker, | |||
167 | /// will be used. Tags are used to prevent states generated at | |||
168 | /// different sites from caching out. | |||
169 | ExplodedNode *addTransition(ProgramStateRef State = nullptr, | |||
170 | const ProgramPointTag *Tag = nullptr) { | |||
171 | return addTransitionImpl(State ? State : getState(), false, nullptr, Tag); | |||
172 | } | |||
173 | ||||
174 | /// Generates a new transition with the given predecessor. | |||
175 | /// Allows checkers to generate a chain of nodes. | |||
176 | /// | |||
177 | /// @param State The state of the generated node. | |||
178 | /// @param Pred The transition will be generated from the specified Pred node | |||
179 | /// to the newly generated node. | |||
180 | /// @param Tag The tag to uniquely identify the creation site. | |||
181 | ExplodedNode *addTransition(ProgramStateRef State, ExplodedNode *Pred, | |||
182 | const ProgramPointTag *Tag = nullptr) { | |||
183 | return addTransitionImpl(State, false, Pred, Tag); | |||
184 | } | |||
185 | ||||
186 | /// Generate a sink node. Generating a sink stops exploration of the | |||
187 | /// given path. To create a sink node for the purpose of reporting an error, | |||
188 | /// checkers should use generateErrorNode() instead. | |||
189 | ExplodedNode *generateSink(ProgramStateRef State, ExplodedNode *Pred, | |||
190 | const ProgramPointTag *Tag = nullptr) { | |||
191 | return addTransitionImpl(State ? State : getState(), true, Pred, Tag); | |||
192 | } | |||
193 | ||||
194 | /// Add a sink node to the current path of execution, halting analysis. | |||
195 | void addSink(ProgramStateRef State = nullptr, | |||
196 | const ProgramPointTag *Tag = nullptr) { | |||
197 | if (!State) | |||
198 | State = getState(); | |||
199 | addTransition(State, generateSink(State, getPredecessor())); | |||
200 | } | |||
201 | ||||
202 | /// Generate a transition to a node that will be used to report | |||
203 | /// an error. This node will be a sink. That is, it will stop exploration of | |||
204 | /// the given path. | |||
205 | /// | |||
206 | /// @param State The state of the generated node. | |||
207 | /// @param Tag The tag to uniquely identify the creation site. If null, | |||
208 | /// the default tag for the checker will be used. | |||
209 | ExplodedNode *generateErrorNode(ProgramStateRef State = nullptr, | |||
210 | const ProgramPointTag *Tag = nullptr) { | |||
211 | return generateSink(State, Pred, | |||
212 | (Tag ? Tag : Location.getTag())); | |||
213 | } | |||
214 | ||||
215 | /// Generate a transition to a node that will be used to report | |||
216 | /// an error. This node will be a sink. That is, it will stop exploration of | |||
217 | /// the given path. | |||
218 | /// | |||
219 | /// @param State The state of the generated node. | |||
220 | /// @param Pred The transition will be generated from the specified Pred node | |||
221 | /// to the newly generated node. | |||
222 | /// @param Tag The tag to uniquely identify the creation site. If null, | |||
223 | /// the default tag for the checker will be used. | |||
224 | ExplodedNode *generateErrorNode(ProgramStateRef State, | |||
225 | ExplodedNode *Pred, | |||
226 | const ProgramPointTag *Tag = nullptr) { | |||
227 | return generateSink(State, Pred, | |||
228 | (Tag ? Tag : Location.getTag())); | |||
229 | } | |||
230 | ||||
231 | /// Generate a transition to a node that will be used to report | |||
232 | /// an error. This node will not be a sink. That is, exploration will | |||
233 | /// continue along this path. | |||
234 | /// | |||
235 | /// @param State The state of the generated node. | |||
236 | /// @param Tag The tag to uniquely identify the creation site. If null, | |||
237 | /// the default tag for the checker will be used. | |||
238 | ExplodedNode * | |||
239 | generateNonFatalErrorNode(ProgramStateRef State = nullptr, | |||
240 | const ProgramPointTag *Tag = nullptr) { | |||
241 | return addTransition(State, (Tag ? Tag : Location.getTag())); | |||
242 | } | |||
243 | ||||
244 | /// Generate a transition to a node that will be used to report | |||
245 | /// an error. This node will not be a sink. That is, exploration will | |||
246 | /// continue along this path. | |||
247 | /// | |||
248 | /// @param State The state of the generated node. | |||
249 | /// @param Pred The transition will be generated from the specified Pred node | |||
250 | /// to the newly generated node. | |||
251 | /// @param Tag The tag to uniquely identify the creation site. If null, | |||
252 | /// the default tag for the checker will be used. | |||
253 | ExplodedNode * | |||
254 | generateNonFatalErrorNode(ProgramStateRef State, | |||
255 | ExplodedNode *Pred, | |||
256 | const ProgramPointTag *Tag = nullptr) { | |||
257 | return addTransition(State, Pred, (Tag ? Tag : Location.getTag())); | |||
258 | } | |||
259 | ||||
260 | /// Emit the diagnostics report. | |||
261 | void emitReport(std::unique_ptr<BugReport> R) { | |||
262 | Changed = true; | |||
263 | Eng.getBugReporter().emitReport(std::move(R)); | |||
264 | } | |||
265 | ||||
266 | /// Produce a program point tag that displays an additional path note | |||
267 | /// to the user. This is a lightweight alternative to the | |||
268 | /// BugReporterVisitor mechanism: instead of visiting the bug report | |||
269 | /// node-by-node to restore the sequence of events that led to discovering | |||
270 | /// a bug, you can add notes as you add your transitions. | |||
271 | /// | |||
272 | /// @param Cb Callback with 'BugReporterContext &, BugReport &' parameters. | |||
273 | /// @param IsPrunable Whether the note is prunable. It allows BugReporter | |||
274 | /// to omit the note from the report if it would make the displayed | |||
275 | /// bug path significantly shorter. | |||
276 | LLVM_ATTRIBUTE_RETURNS_NONNULL__attribute__((returns_nonnull)) | |||
277 | const NoteTag *getNoteTag(NoteTag::Callback &&Cb, bool IsPrunable = false) { | |||
278 | return Eng.getDataTags().make<NoteTag>(std::move(Cb), IsPrunable); | |||
279 | } | |||
280 | ||||
281 | /// A shorthand version of getNoteTag that doesn't require you to accept | |||
282 | /// the 'BugReporterContext' argument when you don't need it. | |||
283 | /// | |||
284 | /// @param Cb Callback only with 'BugReport &' parameter. | |||
285 | /// @param IsPrunable Whether the note is prunable. It allows BugReporter | |||
286 | /// to omit the note from the report if it would make the displayed | |||
287 | /// bug path significantly shorter. | |||
288 | const NoteTag | |||
289 | *getNoteTag(std::function<std::string(PathSensitiveBugReport &)> &&Cb, | |||
290 | bool IsPrunable = false) { | |||
291 | return getNoteTag( | |||
292 | [Cb](BugReporterContext &, | |||
| ||||
293 | PathSensitiveBugReport &BR) { return Cb(BR); }, | |||
294 | IsPrunable); | |||
295 | } | |||
296 | ||||
297 | /// A shorthand version of getNoteTag that doesn't require you to accept | |||
298 | /// the arguments when you don't need it. | |||
299 | /// | |||
300 | /// @param Cb Callback without parameters. | |||
301 | /// @param IsPrunable Whether the note is prunable. It allows BugReporter | |||
302 | /// to omit the note from the report if it would make the displayed | |||
303 | /// bug path significantly shorter. | |||
304 | const NoteTag *getNoteTag(std::function<std::string()> &&Cb, | |||
305 | bool IsPrunable = false) { | |||
306 | return getNoteTag([Cb](BugReporterContext &, | |||
307 | PathSensitiveBugReport &) { return Cb(); }, | |||
308 | IsPrunable); | |||
309 | } | |||
310 | ||||
311 | /// A shorthand version of getNoteTag that accepts a plain note. | |||
312 | /// | |||
313 | /// @param Note The note. | |||
314 | /// @param IsPrunable Whether the note is prunable. It allows BugReporter | |||
315 | /// to omit the note from the report if it would make the displayed | |||
316 | /// bug path significantly shorter. | |||
317 | const NoteTag *getNoteTag(StringRef Note, bool IsPrunable = false) { | |||
318 | return getNoteTag( | |||
319 | [Note](BugReporterContext &, | |||
320 | PathSensitiveBugReport &) { return std::string(Note); }, | |||
321 | IsPrunable); | |||
322 | } | |||
323 | ||||
324 | /// A shorthand version of getNoteTag that accepts a lambda with stream for | |||
325 | /// note. | |||
326 | /// | |||
327 | /// @param Cb Callback with 'BugReport &' and 'llvm::raw_ostream &'. | |||
328 | /// @param IsPrunable Whether the note is prunable. It allows BugReporter | |||
329 | /// to omit the note from the report if it would make the displayed | |||
330 | /// bug path significantly shorter. | |||
331 | const NoteTag *getNoteTag( | |||
332 | std::function<void(PathSensitiveBugReport &BR, llvm::raw_ostream &OS)> &&Cb, | |||
333 | bool IsPrunable = false) { | |||
334 | return getNoteTag( | |||
335 | [Cb](PathSensitiveBugReport &BR) -> std::string { | |||
336 | llvm::SmallString<128> Str; | |||
337 | llvm::raw_svector_ostream OS(Str); | |||
338 | Cb(BR, OS); | |||
339 | return std::string(OS.str()); | |||
340 | }, | |||
341 | IsPrunable); | |||
342 | } | |||
343 | ||||
344 | /// Returns the word that should be used to refer to the declaration | |||
345 | /// in the report. | |||
346 | StringRef getDeclDescription(const Decl *D); | |||
347 | ||||
348 | /// Get the declaration of the called function (path-sensitive). | |||
349 | const FunctionDecl *getCalleeDecl(const CallExpr *CE) const; | |||
350 | ||||
351 | /// Get the name of the called function (path-sensitive). | |||
352 | StringRef getCalleeName(const FunctionDecl *FunDecl) const; | |||
353 | ||||
354 | /// Get the identifier of the called function (path-sensitive). | |||
355 | const IdentifierInfo *getCalleeIdentifier(const CallExpr *CE) const { | |||
356 | const FunctionDecl *FunDecl = getCalleeDecl(CE); | |||
357 | if (FunDecl) | |||
358 | return FunDecl->getIdentifier(); | |||
359 | else | |||
360 | return nullptr; | |||
361 | } | |||
362 | ||||
363 | /// Get the name of the called function (path-sensitive). | |||
364 | StringRef getCalleeName(const CallExpr *CE) const { | |||
365 | const FunctionDecl *FunDecl = getCalleeDecl(CE); | |||
366 | return getCalleeName(FunDecl); | |||
367 | } | |||
368 | ||||
369 | /// Returns true if the callee is an externally-visible function in the | |||
370 | /// top-level namespace, such as \c malloc. | |||
371 | /// | |||
372 | /// If a name is provided, the function must additionally match the given | |||
373 | /// name. | |||
374 | /// | |||
375 | /// Note that this deliberately excludes C++ library functions in the \c std | |||
376 | /// namespace, but will include C library functions accessed through the | |||
377 | /// \c std namespace. This also does not check if the function is declared | |||
378 | /// as 'extern "C"', or if it uses C++ name mangling. | |||
379 | static bool isCLibraryFunction(const FunctionDecl *FD, | |||
380 | StringRef Name = StringRef()); | |||
381 | ||||
382 | /// Depending on wither the location corresponds to a macro, return | |||
383 | /// either the macro name or the token spelling. | |||
384 | /// | |||
385 | /// This could be useful when checkers' logic depends on whether a function | |||
386 | /// is called with a given macro argument. For example: | |||
387 | /// s = socket(AF_INET,..) | |||
388 | /// If AF_INET is a macro, the result should be treated as a source of taint. | |||
389 | /// | |||
390 | /// \sa clang::Lexer::getSpelling(), clang::Lexer::getImmediateMacroName(). | |||
391 | StringRef getMacroNameOrSpelling(SourceLocation &Loc); | |||
392 | ||||
393 | private: | |||
394 | ExplodedNode *addTransitionImpl(ProgramStateRef State, | |||
395 | bool MarkAsSink, | |||
396 | ExplodedNode *P = nullptr, | |||
397 | const ProgramPointTag *Tag = nullptr) { | |||
398 | // The analyzer may stop exploring if it sees a state it has previously | |||
399 | // visited ("cache out"). The early return here is a defensive check to | |||
400 | // prevent accidental caching out by checker API clients. Unless there is a | |||
401 | // tag or the client checker has requested that the generated node be | |||
402 | // marked as a sink, we assume that a client requesting a transition to a | |||
403 | // state that is the same as the predecessor state has made a mistake. We | |||
404 | // return the predecessor rather than cache out. | |||
405 | // | |||
406 | // TODO: We could potentially change the return to an assertion to alert | |||
407 | // clients to their mistake, but several checkers (including | |||
408 | // DereferenceChecker, CallAndMessageChecker, and DynamicTypePropagation) | |||
409 | // rely upon the defensive behavior and would need to be updated. | |||
410 | if (!State || (State == Pred->getState() && !Tag && !MarkAsSink)) | |||
411 | return Pred; | |||
412 | ||||
413 | Changed = true; | |||
414 | const ProgramPoint &LocalLoc = (Tag ? Location.withTag(Tag) : Location); | |||
415 | if (!P) | |||
416 | P = Pred; | |||
417 | ||||
418 | ExplodedNode *node; | |||
419 | if (MarkAsSink) | |||
420 | node = NB.generateSink(LocalLoc, State, P); | |||
421 | else | |||
422 | node = NB.generateNode(LocalLoc, State, P); | |||
423 | return node; | |||
424 | } | |||
425 | }; | |||
426 | ||||
427 | } // end GR namespace | |||
428 | ||||
429 | } // end clang namespace | |||
430 | ||||
431 | #endif |
1 | // Implementation of std::function -*- C++ -*- |
2 | |
3 | // Copyright (C) 2004-2020 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 include/bits/std_function.h |
26 | * This is an internal header file, included by other library headers. |
27 | * Do not attempt to use it directly. @headername{functional} |
28 | */ |
29 | |
30 | #ifndef _GLIBCXX_STD_FUNCTION_H1 |
31 | #define _GLIBCXX_STD_FUNCTION_H1 1 |
32 | |
33 | #pragma GCC system_header |
34 | |
35 | #if __cplusplus201703L < 201103L |
36 | # include <bits/c++0x_warning.h> |
37 | #else |
38 | |
39 | #if __cpp_rtti199711L |
40 | # include <typeinfo> |
41 | #endif |
42 | #include <bits/stl_function.h> |
43 | #include <bits/invoke.h> |
44 | #include <bits/refwrap.h> |
45 | #include <bits/functexcept.h> |
46 | |
47 | namespace std _GLIBCXX_VISIBILITY(default)__attribute__ ((__visibility__ ("default"))) |
48 | { |
49 | _GLIBCXX_BEGIN_NAMESPACE_VERSION |
50 | |
51 | /** |
52 | * @brief Exception class thrown when class template function's |
53 | * operator() is called with an empty target. |
54 | * @ingroup exceptions |
55 | */ |
56 | class bad_function_call : public std::exception |
57 | { |
58 | public: |
59 | virtual ~bad_function_call() noexcept; |
60 | |
61 | const char* what() const noexcept; |
62 | }; |
63 | |
64 | /** |
65 | * Trait identifying "location-invariant" types, meaning that the |
66 | * address of the object (or any of its members) will not escape. |
67 | * Trivially copyable types are location-invariant and users can |
68 | * specialize this trait for other types. |
69 | */ |
70 | template<typename _Tp> |
71 | struct __is_location_invariant |
72 | : is_trivially_copyable<_Tp>::type |
73 | { }; |
74 | |
75 | class _Undefined_class; |
76 | |
77 | union _Nocopy_types |
78 | { |
79 | void* _M_object; |
80 | const void* _M_const_object; |
81 | void (*_M_function_pointer)(); |
82 | void (_Undefined_class::*_M_member_pointer)(); |
83 | }; |
84 | |
85 | union [[gnu::may_alias]] _Any_data |
86 | { |
87 | void* _M_access() { return &_M_pod_data[0]; } |
88 | const void* _M_access() const { return &_M_pod_data[0]; } |
89 | |
90 | template<typename _Tp> |
91 | _Tp& |
92 | _M_access() |
93 | { return *static_cast<_Tp*>(_M_access()); } |
94 | |
95 | template<typename _Tp> |
96 | const _Tp& |
97 | _M_access() const |
98 | { return *static_cast<const _Tp*>(_M_access()); } |
99 | |
100 | _Nocopy_types _M_unused; |
101 | char _M_pod_data[sizeof(_Nocopy_types)]; |
102 | }; |
103 | |
104 | enum _Manager_operation |
105 | { |
106 | __get_type_info, |
107 | __get_functor_ptr, |
108 | __clone_functor, |
109 | __destroy_functor |
110 | }; |
111 | |
112 | template<typename _Signature> |
113 | class function; |
114 | |
115 | /// Base class of all polymorphic function object wrappers. |
116 | class _Function_base |
117 | { |
118 | public: |
119 | static const size_t _M_max_size = sizeof(_Nocopy_types); |
120 | static const size_t _M_max_align = __alignof__(_Nocopy_types); |
121 | |
122 | template<typename _Functor> |
123 | class _Base_manager |
124 | { |
125 | protected: |
126 | static const bool __stored_locally = |
127 | (__is_location_invariant<_Functor>::value |
128 | && sizeof(_Functor) <= _M_max_size |
129 | && __alignof__(_Functor) <= _M_max_align |
130 | && (_M_max_align % __alignof__(_Functor) == 0)); |
131 | |
132 | typedef integral_constant<bool, __stored_locally> _Local_storage; |
133 | |
134 | // Retrieve a pointer to the function object |
135 | static _Functor* |
136 | _M_get_pointer(const _Any_data& __source) |
137 | { |
138 | if _GLIBCXX17_CONSTEXPRconstexpr (__stored_locally) |
139 | { |
140 | const _Functor& __f = __source._M_access<_Functor>(); |
141 | return const_cast<_Functor*>(std::__addressof(__f)); |
142 | } |
143 | else // have stored a pointer |
144 | return __source._M_access<_Functor*>(); |
145 | } |
146 | |
147 | // Clone a location-invariant function object that fits within |
148 | // an _Any_data structure. |
149 | static void |
150 | _M_clone(_Any_data& __dest, const _Any_data& __source, true_type) |
151 | { |
152 | ::new (__dest._M_access()) _Functor(__source._M_access<_Functor>()); |
153 | } |
154 | |
155 | // Clone a function object that is not location-invariant or |
156 | // that cannot fit into an _Any_data structure. |
157 | static void |
158 | _M_clone(_Any_data& __dest, const _Any_data& __source, false_type) |
159 | { |
160 | __dest._M_access<_Functor*>() = |
161 | new _Functor(*__source._M_access<const _Functor*>()); |
162 | } |
163 | |
164 | // Destroying a location-invariant object may still require |
165 | // destruction. |
166 | static void |
167 | _M_destroy(_Any_data& __victim, true_type) |
168 | { |
169 | __victim._M_access<_Functor>().~_Functor(); |
170 | } |
171 | |
172 | // Destroying an object located on the heap. |
173 | static void |
174 | _M_destroy(_Any_data& __victim, false_type) |
175 | { |
176 | delete __victim._M_access<_Functor*>(); |
177 | } |
178 | |
179 | public: |
180 | static bool |
181 | _M_manager(_Any_data& __dest, const _Any_data& __source, |
182 | _Manager_operation __op) |
183 | { |
184 | switch (__op) |
185 | { |
186 | #if __cpp_rtti199711L |
187 | case __get_type_info: |
188 | __dest._M_access<const type_info*>() = &typeid(_Functor); |
189 | break; |
190 | #endif |
191 | case __get_functor_ptr: |
192 | __dest._M_access<_Functor*>() = _M_get_pointer(__source); |
193 | break; |
194 | |
195 | case __clone_functor: |
196 | _M_clone(__dest, __source, _Local_storage()); |
197 | break; |
198 | |
199 | case __destroy_functor: |
200 | _M_destroy(__dest, _Local_storage()); |
201 | break; |
202 | } |
203 | return false; |
204 | } |
205 | |
206 | static void |
207 | _M_init_functor(_Any_data& __functor, _Functor&& __f) |
208 | { _M_init_functor(__functor, std::move(__f), _Local_storage()); } |
209 | |
210 | template<typename _Signature> |
211 | static bool |
212 | _M_not_empty_function(const function<_Signature>& __f) |
213 | { return static_cast<bool>(__f); } |
214 | |
215 | template<typename _Tp> |
216 | static bool |
217 | _M_not_empty_function(_Tp* __fp) |
218 | { return __fp != nullptr; } |
219 | |
220 | template<typename _Class, typename _Tp> |
221 | static bool |
222 | _M_not_empty_function(_Tp _Class::* __mp) |
223 | { return __mp != nullptr; } |
224 | |
225 | template<typename _Tp> |
226 | static bool |
227 | _M_not_empty_function(const _Tp&) |
228 | { return true; } |
229 | |
230 | private: |
231 | static void |
232 | _M_init_functor(_Any_data& __functor, _Functor&& __f, true_type) |
233 | { ::new (__functor._M_access()) _Functor(std::move(__f)); } |
234 | |
235 | static void |
236 | _M_init_functor(_Any_data& __functor, _Functor&& __f, false_type) |
237 | { __functor._M_access<_Functor*>() = new _Functor(std::move(__f)); } |
238 | }; |
239 | |
240 | _Function_base() : _M_manager(nullptr) { } |
241 | |
242 | ~_Function_base() |
243 | { |
244 | if (_M_manager) |
245 | _M_manager(_M_functor, _M_functor, __destroy_functor); |
246 | } |
247 | |
248 | bool _M_empty() const { return !_M_manager; } |
249 | |
250 | typedef bool (*_Manager_type)(_Any_data&, const _Any_data&, |
251 | _Manager_operation); |
252 | |
253 | _Any_data _M_functor; |
254 | _Manager_type _M_manager; |
255 | }; |
256 | |
257 | template<typename _Signature, typename _Functor> |
258 | class _Function_handler; |
259 | |
260 | template<typename _Res, typename _Functor, typename... _ArgTypes> |
261 | class _Function_handler<_Res(_ArgTypes...), _Functor> |
262 | : public _Function_base::_Base_manager<_Functor> |
263 | { |
264 | typedef _Function_base::_Base_manager<_Functor> _Base; |
265 | |
266 | public: |
267 | static bool |
268 | _M_manager(_Any_data& __dest, const _Any_data& __source, |
269 | _Manager_operation __op) |
270 | { |
271 | switch (__op) |
272 | { |
273 | #if __cpp_rtti199711L |
274 | case __get_type_info: |
275 | __dest._M_access<const type_info*>() = &typeid(_Functor); |
276 | break; |
277 | #endif |
278 | case __get_functor_ptr: |
279 | __dest._M_access<_Functor*>() = _Base::_M_get_pointer(__source); |
280 | break; |
281 | |
282 | default: |
283 | _Base::_M_manager(__dest, __source, __op); |
284 | } |
285 | return false; |
286 | } |
287 | |
288 | static _Res |
289 | _M_invoke(const _Any_data& __functor, _ArgTypes&&... __args) |
290 | { |
291 | return std::__invoke_r<_Res>(*_Base::_M_get_pointer(__functor), |
292 | std::forward<_ArgTypes>(__args)...); |
293 | } |
294 | }; |
295 | |
296 | /** |
297 | * @brief Primary class template for std::function. |
298 | * @ingroup functors |
299 | * |
300 | * Polymorphic function wrapper. |
301 | */ |
302 | template<typename _Res, typename... _ArgTypes> |
303 | class function<_Res(_ArgTypes...)> |
304 | : public _Maybe_unary_or_binary_function<_Res, _ArgTypes...>, |
305 | private _Function_base |
306 | { |
307 | template<typename _Func, |
308 | typename _Res2 = __invoke_result<_Func&, _ArgTypes...>> |
309 | struct _Callable |
310 | : __is_invocable_impl<_Res2, _Res>::type |
311 | { }; |
312 | |
313 | // Used so the return type convertibility checks aren't done when |
314 | // performing overload resolution for copy construction/assignment. |
315 | template<typename _Tp> |
316 | struct _Callable<function, _Tp> : false_type { }; |
317 | |
318 | template<typename _Cond, typename _Tp> |
319 | using _Requires = typename enable_if<_Cond::value, _Tp>::type; |
320 | |
321 | public: |
322 | typedef _Res result_type; |
323 | |
324 | // [3.7.2.1] construct/copy/destroy |
325 | |
326 | /** |
327 | * @brief Default construct creates an empty function call wrapper. |
328 | * @post @c !(bool)*this |
329 | */ |
330 | function() noexcept |
331 | : _Function_base() { } |
332 | |
333 | /** |
334 | * @brief Creates an empty function call wrapper. |
335 | * @post @c !(bool)*this |
336 | */ |
337 | function(nullptr_t) noexcept |
338 | : _Function_base() { } |
339 | |
340 | /** |
341 | * @brief %Function copy constructor. |
342 | * @param __x A %function object with identical call signature. |
343 | * @post @c bool(*this) == bool(__x) |
344 | * |
345 | * The newly-created %function contains a copy of the target of @a |
346 | * __x (if it has one). |
347 | */ |
348 | function(const function& __x); |
349 | |
350 | /** |
351 | * @brief %Function move constructor. |
352 | * @param __x A %function object rvalue with identical call signature. |
353 | * |
354 | * The newly-created %function contains the target of @a __x |
355 | * (if it has one). |
356 | */ |
357 | function(function&& __x) noexcept : _Function_base() |
358 | { |
359 | __x.swap(*this); |
360 | } |
361 | |
362 | /** |
363 | * @brief Builds a %function that targets a copy of the incoming |
364 | * function object. |
365 | * @param __f A %function object that is callable with parameters of |
366 | * type @c T1, @c T2, ..., @c TN and returns a value convertible |
367 | * to @c Res. |
368 | * |
369 | * The newly-created %function object will target a copy of |
370 | * @a __f. If @a __f is @c reference_wrapper<F>, then this function |
371 | * object will contain a reference to the function object @c |
372 | * __f.get(). If @a __f is a NULL function pointer or NULL |
373 | * pointer-to-member, the newly-created object will be empty. |
374 | * |
375 | * If @a __f is a non-NULL function pointer or an object of type @c |
376 | * reference_wrapper<F>, this function will not throw. |
377 | */ |
378 | template<typename _Functor, |
379 | typename = _Requires<__not_<is_same<_Functor, function>>, void>, |
380 | typename = _Requires<_Callable<_Functor>, void>> |
381 | function(_Functor); |
382 | |
383 | /** |
384 | * @brief %Function assignment operator. |
385 | * @param __x A %function with identical call signature. |
386 | * @post @c (bool)*this == (bool)x |
387 | * @returns @c *this |
388 | * |
389 | * The target of @a __x is copied to @c *this. If @a __x has no |
390 | * target, then @c *this will be empty. |
391 | * |
392 | * If @a __x targets a function pointer or a reference to a function |
393 | * object, then this operation will not throw an %exception. |
394 | */ |
395 | function& |
396 | operator=(const function& __x) |
397 | { |
398 | function(__x).swap(*this); |
399 | return *this; |
400 | } |
401 | |
402 | /** |
403 | * @brief %Function move-assignment operator. |
404 | * @param __x A %function rvalue with identical call signature. |
405 | * @returns @c *this |
406 | * |
407 | * The target of @a __x is moved to @c *this. If @a __x has no |
408 | * target, then @c *this will be empty. |
409 | * |
410 | * If @a __x targets a function pointer or a reference to a function |
411 | * object, then this operation will not throw an %exception. |
412 | */ |
413 | function& |
414 | operator=(function&& __x) noexcept |
415 | { |
416 | function(std::move(__x)).swap(*this); |
417 | return *this; |
418 | } |
419 | |
420 | /** |
421 | * @brief %Function assignment to zero. |
422 | * @post @c !(bool)*this |
423 | * @returns @c *this |
424 | * |
425 | * The target of @c *this is deallocated, leaving it empty. |
426 | */ |
427 | function& |
428 | operator=(nullptr_t) noexcept |
429 | { |
430 | if (_M_manager) |
431 | { |
432 | _M_manager(_M_functor, _M_functor, __destroy_functor); |
433 | _M_manager = nullptr; |
434 | _M_invoker = nullptr; |
435 | } |
436 | return *this; |
437 | } |
438 | |
439 | /** |
440 | * @brief %Function assignment to a new target. |
441 | * @param __f A %function object that is callable with parameters of |
442 | * type @c T1, @c T2, ..., @c TN and returns a value convertible |
443 | * to @c Res. |
444 | * @return @c *this |
445 | * |
446 | * This %function object wrapper will target a copy of @a |
447 | * __f. If @a __f is @c reference_wrapper<F>, then this function |
448 | * object will contain a reference to the function object @c |
449 | * __f.get(). If @a __f is a NULL function pointer or NULL |
450 | * pointer-to-member, @c this object will be empty. |
451 | * |
452 | * If @a __f is a non-NULL function pointer or an object of type @c |
453 | * reference_wrapper<F>, this function will not throw. |
454 | */ |
455 | template<typename _Functor> |
456 | _Requires<_Callable<typename decay<_Functor>::type>, function&> |
457 | operator=(_Functor&& __f) |
458 | { |
459 | function(std::forward<_Functor>(__f)).swap(*this); |
460 | return *this; |
461 | } |
462 | |
463 | /// @overload |
464 | template<typename _Functor> |
465 | function& |
466 | operator=(reference_wrapper<_Functor> __f) noexcept |
467 | { |
468 | function(__f).swap(*this); |
469 | return *this; |
470 | } |
471 | |
472 | // [3.7.2.2] function modifiers |
473 | |
474 | /** |
475 | * @brief Swap the targets of two %function objects. |
476 | * @param __x A %function with identical call signature. |
477 | * |
478 | * Swap the targets of @c this function object and @a __f. This |
479 | * function will not throw an %exception. |
480 | */ |
481 | void swap(function& __x) noexcept |
482 | { |
483 | std::swap(_M_functor, __x._M_functor); |
484 | std::swap(_M_manager, __x._M_manager); |
485 | std::swap(_M_invoker, __x._M_invoker); |
486 | } |
487 | |
488 | // [3.7.2.3] function capacity |
489 | |
490 | /** |
491 | * @brief Determine if the %function wrapper has a target. |
492 | * |
493 | * @return @c true when this %function object contains a target, |
494 | * or @c false when it is empty. |
495 | * |
496 | * This function will not throw an %exception. |
497 | */ |
498 | explicit operator bool() const noexcept |
499 | { return !_M_empty(); } |
500 | |
501 | // [3.7.2.4] function invocation |
502 | |
503 | /** |
504 | * @brief Invokes the function targeted by @c *this. |
505 | * @returns the result of the target. |
506 | * @throws bad_function_call when @c !(bool)*this |
507 | * |
508 | * The function call operator invokes the target function object |
509 | * stored by @c this. |
510 | */ |
511 | _Res operator()(_ArgTypes... __args) const; |
512 | |
513 | #if __cpp_rtti199711L |
514 | // [3.7.2.5] function target access |
515 | /** |
516 | * @brief Determine the type of the target of this function object |
517 | * wrapper. |
518 | * |
519 | * @returns the type identifier of the target function object, or |
520 | * @c typeid(void) if @c !(bool)*this. |
521 | * |
522 | * This function will not throw an %exception. |
523 | */ |
524 | const type_info& target_type() const noexcept; |
525 | |
526 | /** |
527 | * @brief Access the stored target function object. |
528 | * |
529 | * @return Returns a pointer to the stored target function object, |
530 | * if @c typeid(_Functor).equals(target_type()); otherwise, a NULL |
531 | * pointer. |
532 | * |
533 | * This function does not throw exceptions. |
534 | * |
535 | * @{ |
536 | */ |
537 | template<typename _Functor> _Functor* target() noexcept; |
538 | |
539 | template<typename _Functor> const _Functor* target() const noexcept; |
540 | // @} |
541 | #endif |
542 | |
543 | private: |
544 | using _Invoker_type = _Res (*)(const _Any_data&, _ArgTypes&&...); |
545 | _Invoker_type _M_invoker; |
546 | }; |
547 | |
548 | #if __cpp_deduction_guides201703L >= 201606 |
549 | template<typename> |
550 | struct __function_guide_helper |
551 | { }; |
552 | |
553 | template<typename _Res, typename _Tp, bool _Nx, typename... _Args> |
554 | struct __function_guide_helper< |
555 | _Res (_Tp::*) (_Args...) noexcept(_Nx) |
556 | > |
557 | { using type = _Res(_Args...); }; |
558 | |
559 | template<typename _Res, typename _Tp, bool _Nx, typename... _Args> |
560 | struct __function_guide_helper< |
561 | _Res (_Tp::*) (_Args...) & noexcept(_Nx) |
562 | > |
563 | { using type = _Res(_Args...); }; |
564 | |
565 | template<typename _Res, typename _Tp, bool _Nx, typename... _Args> |
566 | struct __function_guide_helper< |
567 | _Res (_Tp::*) (_Args...) const noexcept(_Nx) |
568 | > |
569 | { using type = _Res(_Args...); }; |
570 | |
571 | template<typename _Res, typename _Tp, bool _Nx, typename... _Args> |
572 | struct __function_guide_helper< |
573 | _Res (_Tp::*) (_Args...) const & noexcept(_Nx) |
574 | > |
575 | { using type = _Res(_Args...); }; |
576 | |
577 | template<typename _Res, typename... _ArgTypes> |
578 | function(_Res(*)(_ArgTypes...)) -> function<_Res(_ArgTypes...)>; |
579 | |
580 | template<typename _Functor, typename _Signature = typename |
581 | __function_guide_helper<decltype(&_Functor::operator())>::type> |
582 | function(_Functor) -> function<_Signature>; |
583 | #endif |
584 | |
585 | // Out-of-line member definitions. |
586 | template<typename _Res, typename... _ArgTypes> |
587 | function<_Res(_ArgTypes...)>:: |
588 | function(const function& __x) |
589 | : _Function_base() |
590 | { |
591 | if (static_cast<bool>(__x)) |
592 | { |
593 | __x._M_manager(_M_functor, __x._M_functor, __clone_functor); |
594 | _M_invoker = __x._M_invoker; |
595 | _M_manager = __x._M_manager; |
596 | } |
597 | } |
598 | |
599 | template<typename _Res, typename... _ArgTypes> |
600 | template<typename _Functor, typename, typename> |
601 | function<_Res(_ArgTypes...)>:: |
602 | function(_Functor __f) |
603 | : _Function_base() |
604 | { |
605 | typedef _Function_handler<_Res(_ArgTypes...), _Functor> _My_handler; |
606 | |
607 | if (_My_handler::_M_not_empty_function(__f)) |
608 | { |
609 | _My_handler::_M_init_functor(_M_functor, std::move(__f)); |
610 | _M_invoker = &_My_handler::_M_invoke; |
611 | _M_manager = &_My_handler::_M_manager; |
612 | } |
613 | } |
614 | |
615 | template<typename _Res, typename... _ArgTypes> |
616 | _Res |
617 | function<_Res(_ArgTypes...)>:: |
618 | operator()(_ArgTypes... __args) const |
619 | { |
620 | if (_M_empty()) |
621 | __throw_bad_function_call(); |
622 | return _M_invoker(_M_functor, std::forward<_ArgTypes>(__args)...); |
623 | } |
624 | |
625 | #if __cpp_rtti199711L |
626 | template<typename _Res, typename... _ArgTypes> |
627 | const type_info& |
628 | function<_Res(_ArgTypes...)>:: |
629 | target_type() const noexcept |
630 | { |
631 | if (_M_manager) |
632 | { |
633 | _Any_data __typeinfo_result; |
634 | _M_manager(__typeinfo_result, _M_functor, __get_type_info); |
635 | return *__typeinfo_result._M_access<const type_info*>(); |
636 | } |
637 | else |
638 | return typeid(void); |
639 | } |
640 | |
641 | template<typename _Res, typename... _ArgTypes> |
642 | template<typename _Functor> |
643 | _Functor* |
644 | function<_Res(_ArgTypes...)>:: |
645 | target() noexcept |
646 | { |
647 | const function* __const_this = this; |
648 | const _Functor* __func = __const_this->template target<_Functor>(); |
649 | return const_cast<_Functor*>(__func); |
650 | } |
651 | |
652 | template<typename _Res, typename... _ArgTypes> |
653 | template<typename _Functor> |
654 | const _Functor* |
655 | function<_Res(_ArgTypes...)>:: |
656 | target() const noexcept |
657 | { |
658 | if (typeid(_Functor) == target_type() && _M_manager) |
659 | { |
660 | _Any_data __ptr; |
661 | _M_manager(__ptr, _M_functor, __get_functor_ptr); |
662 | return __ptr._M_access<const _Functor*>(); |
663 | } |
664 | else |
665 | return nullptr; |
666 | } |
667 | #endif |
668 | |
669 | // [20.7.15.2.6] null pointer comparisons |
670 | |
671 | /** |
672 | * @brief Compares a polymorphic function object wrapper against 0 |
673 | * (the NULL pointer). |
674 | * @returns @c true if the wrapper has no target, @c false otherwise |
675 | * |
676 | * This function will not throw an %exception. |
677 | */ |
678 | template<typename _Res, typename... _Args> |
679 | inline bool |
680 | operator==(const function<_Res(_Args...)>& __f, nullptr_t) noexcept |
681 | { return !static_cast<bool>(__f); } |
682 | |
683 | #if __cpp_impl_three_way_comparison < 201907L |
684 | /// @overload |
685 | template<typename _Res, typename... _Args> |
686 | inline bool |
687 | operator==(nullptr_t, const function<_Res(_Args...)>& __f) noexcept |
688 | { return !static_cast<bool>(__f); } |
689 | |
690 | /** |
691 | * @brief Compares a polymorphic function object wrapper against 0 |
692 | * (the NULL pointer). |
693 | * @returns @c false if the wrapper has no target, @c true otherwise |
694 | * |
695 | * This function will not throw an %exception. |
696 | */ |
697 | template<typename _Res, typename... _Args> |
698 | inline bool |
699 | operator!=(const function<_Res(_Args...)>& __f, nullptr_t) noexcept |
700 | { return static_cast<bool>(__f); } |
701 | |
702 | /// @overload |
703 | template<typename _Res, typename... _Args> |
704 | inline bool |
705 | operator!=(nullptr_t, const function<_Res(_Args...)>& __f) noexcept |
706 | { return static_cast<bool>(__f); } |
707 | #endif |
708 | |
709 | // [20.7.15.2.7] specialized algorithms |
710 | |
711 | /** |
712 | * @brief Swap the targets of two polymorphic function object wrappers. |
713 | * |
714 | * This function will not throw an %exception. |
715 | */ |
716 | // _GLIBCXX_RESOLVE_LIB_DEFECTS |
717 | // 2062. Effect contradictions w/o no-throw guarantee of std::function swaps |
718 | template<typename _Res, typename... _Args> |
719 | inline void |
720 | swap(function<_Res(_Args...)>& __x, function<_Res(_Args...)>& __y) noexcept |
721 | { __x.swap(__y); } |
722 | |
723 | #if __cplusplus201703L >= 201703L |
724 | namespace __detail::__variant |
725 | { |
726 | template<typename> struct _Never_valueless_alt; // see <variant> |
727 | |
728 | // Provide the strong exception-safety guarantee when emplacing a |
729 | // function into a variant. |
730 | template<typename _Signature> |
731 | struct _Never_valueless_alt<std::function<_Signature>> |
732 | : std::true_type |
733 | { }; |
734 | } // namespace __detail::__variant |
735 | #endif // C++17 |
736 | |
737 | _GLIBCXX_END_NAMESPACE_VERSION |
738 | } // namespace std |
739 | |
740 | #endif // C++11 |
741 | #endif // _GLIBCXX_STD_FUNCTION_H |