From 6064f426a18304e16b51cc79e74c9c2d55ef5a9c Mon Sep 17 00:00:00 2001 From: Anastasia Stulova Date: Thu, 6 Feb 2020 11:56:21 +0000 Subject: [OpenCL] Restrict addr space conversions in nested pointers Address space conversion changes pointer representation. This commit disallows such conversions when they are not legal i.e. for the nested pointers even with compatible address spaces. Because the address space conversion in the nested levels can't be generated to modify the pointers correctly. The behavior implemented is as follows: - Any implicit conversions of nested pointers with different address spaces is rejected. - Any conversion of address spaces in nested pointers in safe casts (e.g. const_cast or static_cast) is rejected. - Conversion in low level C-style or reinterpret_cast is accepted but with a warning (this aligns with OpenCL C behavior). Fixes PR39674 Differential Revision: https://reviews.llvm.org/D73360 --- clang/lib/Sema/SemaCast.cpp | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'clang/lib/Sema/SemaCast.cpp') diff --git a/clang/lib/Sema/SemaCast.cpp b/clang/lib/Sema/SemaCast.cpp index a905ebc..7a8cbca 100644 --- a/clang/lib/Sema/SemaCast.cpp +++ b/clang/lib/Sema/SemaCast.cpp @@ -2311,6 +2311,24 @@ static TryCastResult TryReinterpretCast(Sema &Self, ExprResult &SrcExpr, return SuccessResult; } + // Diagnose address space conversion in nested pointers. + QualType DestPtee = DestType->getPointeeType().isNull() + ? DestType->getPointeeType() + : DestType->getPointeeType()->getPointeeType(); + QualType SrcPtee = SrcType->getPointeeType().isNull() + ? SrcType->getPointeeType() + : SrcType->getPointeeType()->getPointeeType(); + while (!DestPtee.isNull() && !SrcPtee.isNull()) { + if (DestPtee.getAddressSpace() != SrcPtee.getAddressSpace()) { + Self.Diag(OpRange.getBegin(), + diag::warn_bad_cxx_cast_nested_pointer_addr_space) + << CStyle << SrcType << DestType << SrcExpr.get()->getSourceRange(); + break; + } + DestPtee = DestPtee->getPointeeType(); + SrcPtee = SrcPtee->getPointeeType(); + } + // C++ 5.2.10p7: A pointer to an object can be explicitly converted to // a pointer to an object of different type. // Void pointers are not specified, but supported by every compiler out there. -- cgit v1.1