Author: Jan Voung Date: 2025-03-07T08:16:46-05:00 New Revision: 81168e2dc1c2069178b1acd5e302be99d7fb0e45
URL: https://github.com/llvm/llvm-project/commit/81168e2dc1c2069178b1acd5e302be99d7fb0e45 DIFF: https://github.com/llvm/llvm-project/commit/81168e2dc1c2069178b1acd5e302be99d7fb0e45.diff LOG: [clang][dataflow] Add test for crash repro and clean up const accessor handling (#129930) Add test for https://github.com/llvm/llvm-project/issues/125589 The crash is actually incidentally fixed by https://github.com/llvm/llvm-project/pull/128437 since it added a branch for the reference case and would no longer fall through when the return type is a reference to a pointer. Clean up a bit as well: - make the fallback for early returns more consistent (check if returning optional and call transfer function for that case) - check RecordLoc == nullptr in one place - clean up extra spaces in test - clean up parameterization in test of `std::` vs `$ns::$` Added: Modified: clang/lib/Analysis/FlowSensitive/Models/UncheckedOptionalAccessModel.cpp clang/unittests/Analysis/FlowSensitive/UncheckedOptionalAccessModelTest.cpp Removed: ################################################################################ diff --git a/clang/lib/Analysis/FlowSensitive/Models/UncheckedOptionalAccessModel.cpp b/clang/lib/Analysis/FlowSensitive/Models/UncheckedOptionalAccessModel.cpp index 9381c5c42e566..c28424fac8fef 100644 --- a/clang/lib/Analysis/FlowSensitive/Models/UncheckedOptionalAccessModel.cpp +++ b/clang/lib/Analysis/FlowSensitive/Models/UncheckedOptionalAccessModel.cpp @@ -551,83 +551,92 @@ void transferCallReturningOptional(const CallExpr *E, setHasValue(*Loc, State.Env.makeAtomicBoolValue(), State.Env); } -void handleConstMemberCall(const CallExpr *CE, +// Returns true if the const accessor is handled by caching. +// Returns false if we could not cache. We should perform default handling +// in that case. +bool handleConstMemberCall(const CallExpr *CE, dataflow::RecordStorageLocation *RecordLoc, const MatchFinder::MatchResult &Result, LatticeTransferState &State) { - // If the const method returns an optional or reference to an optional. - if (RecordLoc != nullptr && isSupportedOptionalType(CE->getType())) { - const FunctionDecl *DirectCallee = CE->getDirectCallee(); - if (DirectCallee == nullptr) - return; - StorageLocation &Loc = - State.Lattice.getOrCreateConstMethodReturnStorageLocation( - *RecordLoc, DirectCallee, State.Env, [&](StorageLocation &Loc) { - setHasValue(cast<RecordStorageLocation>(Loc), - State.Env.makeAtomicBoolValue(), State.Env); - }); - if (CE->isGLValue()) { - // If the call to the const method returns a reference to an optional, - // link the call expression to the cached StorageLocation. - State.Env.setStorageLocation(*CE, Loc); - } else { - // If the call to the const method returns an optional by value, we - // need to use CopyRecord to link the optional to the result object - // of the call expression. - auto &ResultLoc = State.Env.getResultObjectLocation(*CE); - copyRecord(cast<RecordStorageLocation>(Loc), ResultLoc, State.Env); - } - return; - } + if (RecordLoc == nullptr) + return false; - // Cache if the const method returns a reference - if (RecordLoc != nullptr && CE->isGLValue()) { + // Cache if the const method returns a reference. + if (CE->isGLValue()) { const FunctionDecl *DirectCallee = CE->getDirectCallee(); if (DirectCallee == nullptr) - return; + return false; + // Initialize the optional's "has_value" property to true if the type is + // optional, otherwise no-op. If we want to support const ref to pointers or + // bools we should initialize their values here too. + auto Init = [&](StorageLocation &Loc) { + if (isSupportedOptionalType(CE->getType())) + setHasValue(cast<RecordStorageLocation>(Loc), + State.Env.makeAtomicBoolValue(), State.Env); + }; StorageLocation &Loc = State.Lattice.getOrCreateConstMethodReturnStorageLocation( - *RecordLoc, DirectCallee, State.Env, [&](StorageLocation &Loc) { - // no-op - }); + *RecordLoc, DirectCallee, State.Env, Init); State.Env.setStorageLocation(*CE, Loc); - return; + return true; } - - // Cache if the const method returns a boolean or pointer type. - // We may decide to cache other return types in the future. - if (RecordLoc != nullptr && - (CE->getType()->isBooleanType() || CE->getType()->isPointerType())) { + // PRValue cases: + if (CE->getType()->isBooleanType() || CE->getType()->isPointerType()) { + // If the const method returns a boolean or pointer type. Value *Val = State.Lattice.getOrCreateConstMethodReturnValue(*RecordLoc, CE, State.Env); if (Val == nullptr) - return; + return false; State.Env.setValue(*CE, *Val); - return; + return true; } - - // Perform default handling if the call returns an optional - // but wasn't handled above (if RecordLoc is nullptr). if (isSupportedOptionalType(CE->getType())) { - transferCallReturningOptional(CE, Result, State); + // If the const method returns an optional by value. + const FunctionDecl *DirectCallee = CE->getDirectCallee(); + if (DirectCallee == nullptr) + return false; + StorageLocation &Loc = + State.Lattice.getOrCreateConstMethodReturnStorageLocation( + *RecordLoc, DirectCallee, State.Env, [&](StorageLocation &Loc) { + setHasValue(cast<RecordStorageLocation>(Loc), + State.Env.makeAtomicBoolValue(), State.Env); + }); + // Use copyRecord to link the optional to the result object of the call + // expression. + auto &ResultLoc = State.Env.getResultObjectLocation(*CE); + copyRecord(cast<RecordStorageLocation>(Loc), ResultLoc, State.Env); + return true; } + + return false; } -void transferValue_ConstMemberCall(const CXXMemberCallExpr *MCE, - const MatchFinder::MatchResult &Result, - LatticeTransferState &State) { - handleConstMemberCall( +void handleConstMemberCallWithFallbacks( + const CallExpr *CE, dataflow::RecordStorageLocation *RecordLoc, + const MatchFinder::MatchResult &Result, LatticeTransferState &State) { + if (handleConstMemberCall(CE, RecordLoc, Result, State)) + return; + // Perform default handling if the call returns an optional, but wasn't + // handled by caching. + if (isSupportedOptionalType(CE->getType())) + transferCallReturningOptional(CE, Result, State); +} + +void transferConstMemberCall(const CXXMemberCallExpr *MCE, + const MatchFinder::MatchResult &Result, + LatticeTransferState &State) { + handleConstMemberCallWithFallbacks( MCE, dataflow::getImplicitObjectLocation(*MCE, State.Env), Result, State); } -void transferValue_ConstMemberOperatorCall( - const CXXOperatorCallExpr *OCE, const MatchFinder::MatchResult &Result, - LatticeTransferState &State) { +void transferConstMemberOperatorCall(const CXXOperatorCallExpr *OCE, + const MatchFinder::MatchResult &Result, + LatticeTransferState &State) { auto *RecordLoc = cast_or_null<dataflow::RecordStorageLocation>( State.Env.getStorageLocation(*OCE->getArg(0))); - handleConstMemberCall(OCE, RecordLoc, Result, State); + handleConstMemberCallWithFallbacks(OCE, RecordLoc, Result, State); } void handleNonConstMemberCall(const CallExpr *CE, @@ -1094,9 +1103,9 @@ auto buildTransferMatchSwitch() { // const accessor calls .CaseOfCFGStmt<CXXMemberCallExpr>(isZeroParamConstMemberCall(), - transferValue_ConstMemberCall) + transferConstMemberCall) .CaseOfCFGStmt<CXXOperatorCallExpr>(isZeroParamConstMemberOperatorCall(), - transferValue_ConstMemberOperatorCall) + transferConstMemberOperatorCall) // non-const member calls that may modify the state of an object. .CaseOfCFGStmt<CXXMemberCallExpr>(isNonConstMemberCall(), transferValue_NonConstMemberCall) diff --git a/clang/unittests/Analysis/FlowSensitive/UncheckedOptionalAccessModelTest.cpp b/clang/unittests/Analysis/FlowSensitive/UncheckedOptionalAccessModelTest.cpp index 5031e17188e17..46fad6b655c4d 100644 --- a/clang/unittests/Analysis/FlowSensitive/UncheckedOptionalAccessModelTest.cpp +++ b/clang/unittests/Analysis/FlowSensitive/UncheckedOptionalAccessModelTest.cpp @@ -3829,7 +3829,7 @@ TEST_P(UncheckedOptionalAccessTest, ConstBoolAccessor) { }; void target(A& a) { - std::optional<int> opt; + $ns::$optional<int> opt; if (a.isFoo()) { opt = 1; } @@ -3851,7 +3851,7 @@ TEST_P(UncheckedOptionalAccessTest, ConstBoolAccessorWithModInBetween) { }; void target(A& a) { - std::optional<int> opt; + $ns::$optional<int> opt; if (a.isFoo()) { opt = 1; } @@ -3870,13 +3870,13 @@ TEST_P(UncheckedOptionalAccessTest, struct A { const $ns::$optional<int>& get() const { return x; } - + $ns::$optional<int> x; }; struct B { const A& getA() const { return a; } - + A a; }; @@ -3896,13 +3896,13 @@ TEST_P( struct A { const $ns::$optional<int>& get() const { return x; } - + $ns::$optional<int> x; }; struct B { const A& getA() const { return a; } - + A a; }; @@ -3919,13 +3919,13 @@ TEST_P(UncheckedOptionalAccessTest, struct A { const $ns::$optional<int>& get() const { return x; } - + $ns::$optional<int> x; }; struct B { const A& getA() const { return a; } - + A a; }; @@ -3945,13 +3945,13 @@ TEST_P(UncheckedOptionalAccessTest, struct A { const $ns::$optional<int>& get() const { return x; } - + $ns::$optional<int> x; }; struct B { const A copyA() const { return a; } - + A a; }; @@ -3970,13 +3970,13 @@ TEST_P(UncheckedOptionalAccessTest, struct A { const $ns::$optional<int>& get() const { return x; } - + $ns::$optional<int> x; }; struct B { A& getA() { return a; } - + A a; }; @@ -4031,23 +4031,23 @@ TEST_P( ConstRefAccessorToOptionalViaConstRefAccessorToHoldingObjectWithAnotherConstCallAfterCheck) { ExpectDiagnosticsFor(R"cc( #include "unchecked_optional_access_test.h" - + struct A { const $ns::$optional<int>& get() const { return x; } - + $ns::$optional<int> x; }; - + struct B { const A& getA() const { return a; } - + void callWithoutChanges() const { // no-op } - + A a; }; - + void target(B& b) { if (b.getA().get().has_value()) { b.callWithoutChanges(); // calling const method which cannot change A @@ -4057,6 +4057,34 @@ TEST_P( )cc"); } +TEST_P(UncheckedOptionalAccessTest, ConstPointerRefAccessor) { + // A crash reproducer for https://github.com/llvm/llvm-project/issues/125589 + // NOTE: we currently cache const ref accessors's locations. + // If we want to support const ref to pointers or bools, we should initialize + // their values. + ExpectDiagnosticsFor(R"cc( + #include "unchecked_optional_access_test.h" + + struct A { + $ns::$optional<int> x; + }; + + struct PtrWrapper { + A*& getPtrRef() const; + void reset(A*); + }; + + void target(PtrWrapper p) { + if (p.getPtrRef()->x) { + *p.getPtrRef()->x; // [[unsafe]] + p.reset(nullptr); + *p.getPtrRef()->x; // [[unsafe]] + } + } + )cc", + /*IgnoreSmartPointerDereference=*/false); +} + // FIXME: Add support for: // - constructors (copy, move) // - assignment operators (default, copy, move) _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
