On Fri, 20 Jul 2018 at 04:38, Yaxun Liu via cfe-commits < cfe-commits@lists.llvm.org> wrote:
> Author: yaxunl > Date: Fri Jul 20 04:32:51 2018 > New Revision: 337540 > > URL: http://llvm.org/viewvc/llvm-project?rev=337540&view=rev > Log: > Sema: Fix explicit address space cast in C++ > > Currently clang does not allow implicit cast of a pointer to a pointer type > in different address space but allows C-style cast of a pointer to a > pointer > type in different address space. However, there is a bug in Sema causing > incorrect Cast Expr in AST for the latter case, which in turn results in > invalid LLVM IR in codegen. > > This is because Sema::IsQualificationConversion returns true for a cast of > pointer to a pointer type in different address space, which in turn allows > a standard conversion and results in a cast expression with no op in AST. > > This patch fixes that by let Sema::IsQualificationConversion returns false > for a cast of pointer to a pointer type in different address space, which > in turn disallows standard conversion, implicit cast, and static cast. > Finally it results in an reinterpret cast and correct conversion kind is > set. > > Differential Revision: https://reviews.llvm.org/D49294 > > Added: > cfe/trunk/test/CodeGenCXX/address-space-cast.cpp > Modified: > cfe/trunk/lib/Sema/SemaCast.cpp > cfe/trunk/lib/Sema/SemaOverload.cpp > > Modified: cfe/trunk/lib/Sema/SemaCast.cpp > URL: > http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaCast.cpp?rev=337540&r1=337539&r2=337540&view=diff > > ============================================================================== > --- cfe/trunk/lib/Sema/SemaCast.cpp (original) > +++ cfe/trunk/lib/Sema/SemaCast.cpp Fri Jul 20 04:32:51 2018 > @@ -1955,6 +1955,12 @@ static bool fixOverloadedReinterpretCast > return Result.isUsable(); > } > > +static bool IsAddressSpaceConversion(QualType SrcType, QualType DestType) > { > + return SrcType->isPointerType() && DestType->isPointerType() && > + > SrcType->getAs<PointerType>()->getPointeeType().getAddressSpace() != > + > DestType->getAs<PointerType>()->getPointeeType().getAddressSpace(); > +} > + > static TryCastResult TryReinterpretCast(Sema &Self, ExprResult &SrcExpr, > QualType DestType, bool CStyle, > SourceRange OpRange, > @@ -2198,6 +2204,8 @@ static TryCastResult TryReinterpretCast( > } else { > Kind = CK_BitCast; > } > + } else if (IsAddressSpaceConversion(SrcType, DestType)) { > + Kind = CK_AddressSpaceConversion; > This seems wrong to me. A reinterpret_cast from a pointer to one address space into a pointer to a different address space should be a bit cast, not an address space conversion. > } else { > Kind = CK_BitCast; > } > > Modified: cfe/trunk/lib/Sema/SemaOverload.cpp > URL: > http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaOverload.cpp?rev=337540&r1=337539&r2=337540&view=diff > > ============================================================================== > --- cfe/trunk/lib/Sema/SemaOverload.cpp (original) > +++ cfe/trunk/lib/Sema/SemaOverload.cpp Fri Jul 20 04:32:51 2018 > @@ -3150,6 +3150,15 @@ Sema::IsQualificationConversion(QualType > = PreviousToQualsIncludeConst && ToQuals.hasConst(); > } > > + // Allows address space promotion by language rules implemented in > + // Type::Qualifiers::isAddressSpaceSupersetOf. > + Qualifiers FromQuals = FromType.getQualifiers(); > + Qualifiers ToQuals = ToType.getQualifiers(); > + if (!ToQuals.isAddressSpaceSupersetOf(FromQuals) && > + !FromQuals.isAddressSpaceSupersetOf(ToQuals)) { > + return false; > + } > + > // We are left with FromType and ToType being the pointee types > // after unwrapping the original FromType and ToType the same number > // of types. If we unwrapped any pointers, and if FromType and > > Added: cfe/trunk/test/CodeGenCXX/address-space-cast.cpp > URL: > http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/address-space-cast.cpp?rev=337540&view=auto > > ============================================================================== > --- cfe/trunk/test/CodeGenCXX/address-space-cast.cpp (added) > +++ cfe/trunk/test/CodeGenCXX/address-space-cast.cpp Fri Jul 20 04:32:51 > 2018 > @@ -0,0 +1,15 @@ > +// RUN: %clang_cc1 %s -triple=amdgcn-amd-amdhsa -emit-llvm -o - | > FileCheck %s > + > +#define __private__ __attribute__((address_space(5))) > + > +void func_pchar(__private__ char *x); > + > +void test_cast(char *gen_ptr) { > + // CHECK: %[[cast:.*]] = addrspacecast i8* %{{.*}} to i8 addrspace(5)* > + // CHECK-NEXT: store i8 addrspace(5)* %[[cast]] > + __private__ char *priv_ptr = (__private__ char *)gen_ptr; > + > + // CHECK: %[[cast:.*]] = addrspacecast i8* %{{.*}} to i8 addrspace(5)* > + // CHECK-NEXT: call void @_Z10func_pcharPU3AS5c(i8 addrspace(5)* > %[[cast]]) > + func_pchar((__private__ char *)gen_ptr); > +} > > > _______________________________________________ > cfe-commits mailing list > cfe-commits@lists.llvm.org > http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits >
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