https://github.com/11happy created https://github.com/llvm/llvm-project/pull/80040
**Overview:** This pull request fixes #79443 when the cleanup attribute is intended to be applied to a variable declaration, passing its address to a specified function. The problem arises when standard functions like free, closedir, fclose, etc., are used incorrectly with this attribute, leading to incorrect behavior. **Testing:** - Tested the updated code. - Verified that other functionalities remain unaffected.   **Dependencies:** - No dependencies on other pull requests. **CC:** - @AaronBallman >From 93adb872d0e18ff3a1356ab47527d81b61c920cd Mon Sep 17 00:00:00 2001 From: 11happy <soni5ha...@gmail.com> Date: Tue, 30 Jan 2024 23:19:04 +0530 Subject: [PATCH] Diagnose misuse of the cleanup attribute Signed-off-by: 11happy <soni5ha...@gmail.com> --- .../include/clang/Basic/DiagnosticSemaKinds.td | 4 ++++ clang/include/clang/Sema/Sema.h | 2 ++ clang/lib/Sema/SemaDeclAttr.cpp | 7 +++++++ clang/lib/Sema/SemaExpr.cpp | 17 +++++++++++++++++ 4 files changed, 30 insertions(+) diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td index 24d32cb87c89e..99ef803b1e0ec 100644 --- a/clang/include/clang/Basic/DiagnosticSemaKinds.td +++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td @@ -8265,6 +8265,10 @@ def warn_condition_is_assignment : Warning<"using the result of an " def warn_free_nonheap_object : Warning<"attempt to call %0 on non-heap %select{object %2|object: block expression|object: lambda-to-function-pointer conversion}1">, InGroup<FreeNonHeapObject>; +def warn_free_called_on_unallocated_object : Warning< + "'%0' called on unallocated object '%1'">, + InGroup<FreeNonHeapObject>; + // Completely identical except off by default. def warn_condition_is_idiomatic_assignment : Warning<"using the result " diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h index b5946e3f3178f..535c479aeb7c5 100644 --- a/clang/include/clang/Sema/Sema.h +++ b/clang/include/clang/Sema/Sema.h @@ -12932,6 +12932,8 @@ class Sema final { bool IsStringLiteralToNonConstPointerConversion(Expr *From, QualType ToType); + bool IsPointerToPointer(QualType LHSType, QualType RHSType); + bool CheckExceptionSpecCompatibility(Expr *From, QualType ToType); ExprResult PerformImplicitConversion(Expr *From, QualType ToType, diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp index 069571fcf7864..e149f745cc2f9 100644 --- a/clang/lib/Sema/SemaDeclAttr.cpp +++ b/clang/lib/Sema/SemaDeclAttr.cpp @@ -3782,6 +3782,13 @@ static void handleCleanupAttr(Sema &S, Decl *D, const ParsedAttr &AL) { } D->addAttr(::new (S.Context) CleanupAttr(S.Context, AL, FD)); + + if (S.IsPointerToPointer(ParamTy, Ty)) { + VarDecl *VD = cast<VarDecl>(D); + S.Diag(Loc, diag::warn_free_called_on_unallocated_object) + << NI.getName() << VD; + return; + } } static void handleEnumExtensibilityAttr(Sema &S, Decl *D, diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp index 2f1ddfb215116..255e0be3cc842 100644 --- a/clang/lib/Sema/SemaExpr.cpp +++ b/clang/lib/Sema/SemaExpr.cpp @@ -10098,6 +10098,23 @@ static bool isVector(QualType QT, QualType ElementType) { return false; } +bool Sema::IsPointerToPointer(QualType LHSType, QualType RHSType) { + if (const PointerType *LHSPointer = dyn_cast<PointerType>(LHSType)) { + // Check if LHS is a single pointer, not a pointer to a pointer. + if (!isa<PointerType>(LHSPointer->getPointeeType())) { + if (isa<PointerType>(RHSType)) { + if (const PointerType *RHSPtr = dyn_cast<PointerType>(RHSType)) { + // If RHSType is a pointer to a pointer type, return True + if (isa<PointerType>(RHSPtr->getPointeeType())) { + return true; + } + } + } + } + } + return false; +} + /// CheckAssignmentConstraints (C99 6.5.16) - This routine currently /// has code to accommodate several GCC extensions when type checking /// pointers. Here are some objectionable examples that GCC considers warnings: _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
