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Diffstat (limited to 'contrib/llvm/tools/clang/lib/Sema/SemaCUDA.cpp')
-rw-r--r-- | contrib/llvm/tools/clang/lib/Sema/SemaCUDA.cpp | 424 |
1 files changed, 424 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/lib/Sema/SemaCUDA.cpp b/contrib/llvm/tools/clang/lib/Sema/SemaCUDA.cpp new file mode 100644 index 0000000..61dfdd3 --- /dev/null +++ b/contrib/llvm/tools/clang/lib/Sema/SemaCUDA.cpp @@ -0,0 +1,424 @@ +//===--- SemaCUDA.cpp - Semantic Analysis for CUDA constructs -------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +/// \file +/// \brief This file implements semantic analysis for CUDA constructs. +/// +//===----------------------------------------------------------------------===// + +#include "clang/Sema/Sema.h" +#include "clang/AST/ASTContext.h" +#include "clang/AST/Decl.h" +#include "clang/Lex/Preprocessor.h" +#include "clang/Sema/SemaDiagnostic.h" +#include "llvm/ADT/Optional.h" +#include "llvm/ADT/SmallVector.h" +using namespace clang; + +ExprResult Sema::ActOnCUDAExecConfigExpr(Scope *S, SourceLocation LLLLoc, + MultiExprArg ExecConfig, + SourceLocation GGGLoc) { + FunctionDecl *ConfigDecl = Context.getcudaConfigureCallDecl(); + if (!ConfigDecl) + return ExprError(Diag(LLLLoc, diag::err_undeclared_var_use) + << "cudaConfigureCall"); + QualType ConfigQTy = ConfigDecl->getType(); + + DeclRefExpr *ConfigDR = new (Context) + DeclRefExpr(ConfigDecl, false, ConfigQTy, VK_LValue, LLLLoc); + MarkFunctionReferenced(LLLLoc, ConfigDecl); + + return ActOnCallExpr(S, ConfigDR, LLLLoc, ExecConfig, GGGLoc, nullptr, + /*IsExecConfig=*/true); +} + +/// IdentifyCUDATarget - Determine the CUDA compilation target for this function +Sema::CUDAFunctionTarget Sema::IdentifyCUDATarget(const FunctionDecl *D) { + if (D->hasAttr<CUDAInvalidTargetAttr>()) + return CFT_InvalidTarget; + + if (D->hasAttr<CUDAGlobalAttr>()) + return CFT_Global; + + if (D->hasAttr<CUDADeviceAttr>()) { + if (D->hasAttr<CUDAHostAttr>()) + return CFT_HostDevice; + return CFT_Device; + } else if (D->hasAttr<CUDAHostAttr>()) { + return CFT_Host; + } else if (D->isImplicit()) { + // Some implicit declarations (like intrinsic functions) are not marked. + // Set the most lenient target on them for maximal flexibility. + return CFT_HostDevice; + } + + return CFT_Host; +} + +// * CUDA Call preference table +// +// F - from, +// T - to +// Ph - preference in host mode +// Pd - preference in device mode +// H - handled in (x) +// Preferences: b-best, f-fallback, l-last resort, n-never. +// +// | F | T | Ph | Pd | H | +// |----+----+----+----+-----+ +// | d | d | b | b | (b) | +// | d | g | n | n | (a) | +// | d | h | l | l | (e) | +// | d | hd | f | f | (c) | +// | g | d | b | b | (b) | +// | g | g | n | n | (a) | +// | g | h | l | l | (e) | +// | g | hd | f | f | (c) | +// | h | d | l | l | (e) | +// | h | g | b | b | (b) | +// | h | h | b | b | (b) | +// | h | hd | f | f | (c) | +// | hd | d | l | f | (d) | +// | hd | g | f | n |(d/a)| +// | hd | h | f | l | (d) | +// | hd | hd | b | b | (b) | + +Sema::CUDAFunctionPreference +Sema::IdentifyCUDAPreference(const FunctionDecl *Caller, + const FunctionDecl *Callee) { + assert(getLangOpts().CUDATargetOverloads && + "Should not be called w/o enabled target overloads."); + + assert(Callee && "Callee must be valid."); + CUDAFunctionTarget CalleeTarget = IdentifyCUDATarget(Callee); + CUDAFunctionTarget CallerTarget = + (Caller != nullptr) ? IdentifyCUDATarget(Caller) : Sema::CFT_Host; + + // If one of the targets is invalid, the check always fails, no matter what + // the other target is. + if (CallerTarget == CFT_InvalidTarget || CalleeTarget == CFT_InvalidTarget) + return CFP_Never; + + // (a) Can't call global from some contexts until we support CUDA's + // dynamic parallelism. + if (CalleeTarget == CFT_Global && + (CallerTarget == CFT_Global || CallerTarget == CFT_Device || + (CallerTarget == CFT_HostDevice && getLangOpts().CUDAIsDevice))) + return CFP_Never; + + // (b) Best case scenarios + if (CalleeTarget == CallerTarget || + (CallerTarget == CFT_Host && CalleeTarget == CFT_Global) || + (CallerTarget == CFT_Global && CalleeTarget == CFT_Device)) + return CFP_Best; + + // (c) Calling HostDevice is OK as a fallback that works for everyone. + if (CalleeTarget == CFT_HostDevice) + return CFP_Fallback; + + // Figure out what should be returned 'last resort' cases. Normally + // those would not be allowed, but we'll consider them if + // CUDADisableTargetCallChecks is true. + CUDAFunctionPreference QuestionableResult = + getLangOpts().CUDADisableTargetCallChecks ? CFP_LastResort : CFP_Never; + + // (d) HostDevice behavior depends on compilation mode. + if (CallerTarget == CFT_HostDevice) { + // Calling a function that matches compilation mode is OK. + // Calling a function from the other side is frowned upon. + if (getLangOpts().CUDAIsDevice) + return CalleeTarget == CFT_Device ? CFP_Fallback : QuestionableResult; + else + return (CalleeTarget == CFT_Host || CalleeTarget == CFT_Global) + ? CFP_Fallback + : QuestionableResult; + } + + // (e) Calling across device/host boundary is not something you should do. + if ((CallerTarget == CFT_Host && CalleeTarget == CFT_Device) || + (CallerTarget == CFT_Device && CalleeTarget == CFT_Host) || + (CallerTarget == CFT_Global && CalleeTarget == CFT_Host)) + return QuestionableResult; + + llvm_unreachable("All cases should've been handled by now."); +} + +bool Sema::CheckCUDATarget(const FunctionDecl *Caller, + const FunctionDecl *Callee) { + // With target overloads enabled, we only disallow calling + // combinations with CFP_Never. + if (getLangOpts().CUDATargetOverloads) + return IdentifyCUDAPreference(Caller,Callee) == CFP_Never; + + // The CUDADisableTargetCallChecks short-circuits this check: we assume all + // cross-target calls are valid. + if (getLangOpts().CUDADisableTargetCallChecks) + return false; + + CUDAFunctionTarget CallerTarget = IdentifyCUDATarget(Caller), + CalleeTarget = IdentifyCUDATarget(Callee); + + // If one of the targets is invalid, the check always fails, no matter what + // the other target is. + if (CallerTarget == CFT_InvalidTarget || CalleeTarget == CFT_InvalidTarget) + return true; + + // CUDA B.1.1 "The __device__ qualifier declares a function that is [...] + // Callable from the device only." + if (CallerTarget == CFT_Host && CalleeTarget == CFT_Device) + return true; + + // CUDA B.1.2 "The __global__ qualifier declares a function that is [...] + // Callable from the host only." + // CUDA B.1.3 "The __host__ qualifier declares a function that is [...] + // Callable from the host only." + if ((CallerTarget == CFT_Device || CallerTarget == CFT_Global) && + (CalleeTarget == CFT_Host || CalleeTarget == CFT_Global)) + return true; + + // CUDA B.1.3 "The __device__ and __host__ qualifiers can be used together + // however, in which case the function is compiled for both the host and the + // device. The __CUDA_ARCH__ macro [...] can be used to differentiate code + // paths between host and device." + if (CallerTarget == CFT_HostDevice && CalleeTarget != CFT_HostDevice) { + // If the caller is implicit then the check always passes. + if (Caller->isImplicit()) return false; + + bool InDeviceMode = getLangOpts().CUDAIsDevice; + if (!InDeviceMode && CalleeTarget != CFT_Host) + return true; + if (InDeviceMode && CalleeTarget != CFT_Device) { + // Allow host device functions to call host functions if explicitly + // requested. + if (CalleeTarget == CFT_Host && + getLangOpts().CUDAAllowHostCallsFromHostDevice) { + Diag(Caller->getLocation(), + diag::warn_host_calls_from_host_device) + << Callee->getNameAsString() << Caller->getNameAsString(); + return false; + } + + return true; + } + } + + return false; +} + +template <typename T, typename FetchDeclFn> +static void EraseUnwantedCUDAMatchesImpl(Sema &S, const FunctionDecl *Caller, + llvm::SmallVectorImpl<T> &Matches, + FetchDeclFn FetchDecl) { + assert(S.getLangOpts().CUDATargetOverloads && + "Should not be called w/o enabled target overloads."); + if (Matches.size() <= 1) + return; + + // Find the best call preference among the functions in Matches. + Sema::CUDAFunctionPreference P, BestCFP = Sema::CFP_Never; + for (auto const &Match : Matches) { + P = S.IdentifyCUDAPreference(Caller, FetchDecl(Match)); + if (P > BestCFP) + BestCFP = P; + } + + // Erase all functions with lower priority. + for (unsigned I = 0, N = Matches.size(); I != N;) + if (S.IdentifyCUDAPreference(Caller, FetchDecl(Matches[I])) < BestCFP) { + Matches[I] = Matches[--N]; + Matches.resize(N); + } else { + ++I; + } +} + +void Sema::EraseUnwantedCUDAMatches(const FunctionDecl *Caller, + SmallVectorImpl<FunctionDecl *> &Matches){ + EraseUnwantedCUDAMatchesImpl<FunctionDecl *>( + *this, Caller, Matches, [](const FunctionDecl *item) { return item; }); +} + +void Sema::EraseUnwantedCUDAMatches(const FunctionDecl *Caller, + SmallVectorImpl<DeclAccessPair> &Matches) { + EraseUnwantedCUDAMatchesImpl<DeclAccessPair>( + *this, Caller, Matches, [](const DeclAccessPair &item) { + return dyn_cast<FunctionDecl>(item.getDecl()); + }); +} + +void Sema::EraseUnwantedCUDAMatches( + const FunctionDecl *Caller, + SmallVectorImpl<std::pair<DeclAccessPair, FunctionDecl *>> &Matches){ + EraseUnwantedCUDAMatchesImpl<std::pair<DeclAccessPair, FunctionDecl *>>( + *this, Caller, Matches, + [](const std::pair<DeclAccessPair, FunctionDecl *> &item) { + return dyn_cast<FunctionDecl>(item.second); + }); +} + +/// When an implicitly-declared special member has to invoke more than one +/// base/field special member, conflicts may occur in the targets of these +/// members. For example, if one base's member __host__ and another's is +/// __device__, it's a conflict. +/// This function figures out if the given targets \param Target1 and +/// \param Target2 conflict, and if they do not it fills in +/// \param ResolvedTarget with a target that resolves for both calls. +/// \return true if there's a conflict, false otherwise. +static bool +resolveCalleeCUDATargetConflict(Sema::CUDAFunctionTarget Target1, + Sema::CUDAFunctionTarget Target2, + Sema::CUDAFunctionTarget *ResolvedTarget) { + if (Target1 == Sema::CFT_Global && Target2 == Sema::CFT_Global) { + // TODO: this shouldn't happen, really. Methods cannot be marked __global__. + // Clang should detect this earlier and produce an error. Then this + // condition can be changed to an assertion. + return true; + } + + if (Target1 == Sema::CFT_HostDevice) { + *ResolvedTarget = Target2; + } else if (Target2 == Sema::CFT_HostDevice) { + *ResolvedTarget = Target1; + } else if (Target1 != Target2) { + return true; + } else { + *ResolvedTarget = Target1; + } + + return false; +} + +bool Sema::inferCUDATargetForImplicitSpecialMember(CXXRecordDecl *ClassDecl, + CXXSpecialMember CSM, + CXXMethodDecl *MemberDecl, + bool ConstRHS, + bool Diagnose) { + llvm::Optional<CUDAFunctionTarget> InferredTarget; + + // We're going to invoke special member lookup; mark that these special + // members are called from this one, and not from its caller. + ContextRAII MethodContext(*this, MemberDecl); + + // Look for special members in base classes that should be invoked from here. + // Infer the target of this member base on the ones it should call. + // Skip direct and indirect virtual bases for abstract classes. + llvm::SmallVector<const CXXBaseSpecifier *, 16> Bases; + for (const auto &B : ClassDecl->bases()) { + if (!B.isVirtual()) { + Bases.push_back(&B); + } + } + + if (!ClassDecl->isAbstract()) { + for (const auto &VB : ClassDecl->vbases()) { + Bases.push_back(&VB); + } + } + + for (const auto *B : Bases) { + const RecordType *BaseType = B->getType()->getAs<RecordType>(); + if (!BaseType) { + continue; + } + + CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseType->getDecl()); + Sema::SpecialMemberOverloadResult *SMOR = + LookupSpecialMember(BaseClassDecl, CSM, + /* ConstArg */ ConstRHS, + /* VolatileArg */ false, + /* RValueThis */ false, + /* ConstThis */ false, + /* VolatileThis */ false); + + if (!SMOR || !SMOR->getMethod()) { + continue; + } + + CUDAFunctionTarget BaseMethodTarget = IdentifyCUDATarget(SMOR->getMethod()); + if (!InferredTarget.hasValue()) { + InferredTarget = BaseMethodTarget; + } else { + bool ResolutionError = resolveCalleeCUDATargetConflict( + InferredTarget.getValue(), BaseMethodTarget, + InferredTarget.getPointer()); + if (ResolutionError) { + if (Diagnose) { + Diag(ClassDecl->getLocation(), + diag::note_implicit_member_target_infer_collision) + << (unsigned)CSM << InferredTarget.getValue() << BaseMethodTarget; + } + MemberDecl->addAttr(CUDAInvalidTargetAttr::CreateImplicit(Context)); + return true; + } + } + } + + // Same as for bases, but now for special members of fields. + for (const auto *F : ClassDecl->fields()) { + if (F->isInvalidDecl()) { + continue; + } + + const RecordType *FieldType = + Context.getBaseElementType(F->getType())->getAs<RecordType>(); + if (!FieldType) { + continue; + } + + CXXRecordDecl *FieldRecDecl = cast<CXXRecordDecl>(FieldType->getDecl()); + Sema::SpecialMemberOverloadResult *SMOR = + LookupSpecialMember(FieldRecDecl, CSM, + /* ConstArg */ ConstRHS && !F->isMutable(), + /* VolatileArg */ false, + /* RValueThis */ false, + /* ConstThis */ false, + /* VolatileThis */ false); + + if (!SMOR || !SMOR->getMethod()) { + continue; + } + + CUDAFunctionTarget FieldMethodTarget = + IdentifyCUDATarget(SMOR->getMethod()); + if (!InferredTarget.hasValue()) { + InferredTarget = FieldMethodTarget; + } else { + bool ResolutionError = resolveCalleeCUDATargetConflict( + InferredTarget.getValue(), FieldMethodTarget, + InferredTarget.getPointer()); + if (ResolutionError) { + if (Diagnose) { + Diag(ClassDecl->getLocation(), + diag::note_implicit_member_target_infer_collision) + << (unsigned)CSM << InferredTarget.getValue() + << FieldMethodTarget; + } + MemberDecl->addAttr(CUDAInvalidTargetAttr::CreateImplicit(Context)); + return true; + } + } + } + + if (InferredTarget.hasValue()) { + if (InferredTarget.getValue() == CFT_Device) { + MemberDecl->addAttr(CUDADeviceAttr::CreateImplicit(Context)); + } else if (InferredTarget.getValue() == CFT_Host) { + MemberDecl->addAttr(CUDAHostAttr::CreateImplicit(Context)); + } else { + MemberDecl->addAttr(CUDADeviceAttr::CreateImplicit(Context)); + MemberDecl->addAttr(CUDAHostAttr::CreateImplicit(Context)); + } + } else { + // If no target was inferred, mark this member as __host__ __device__; + // it's the least restrictive option that can be invoked from any target. + MemberDecl->addAttr(CUDADeviceAttr::CreateImplicit(Context)); + MemberDecl->addAttr(CUDAHostAttr::CreateImplicit(Context)); + } + + return false; +} |