================ @@ -0,0 +1,304 @@ +//===----- SemaCUDA.h ----- Semantic Analysis for CUDA constructs ---------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +/// \file +/// This file declares semantic analysis for CUDA constructs. +/// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_CLANG_SEMA_SEMACUDA_H +#define LLVM_CLANG_SEMA_SEMACUDA_H + +#include "clang/AST/Decl.h" +#include "clang/AST/DeclCXX.h" +#include "clang/AST/Redeclarable.h" +#include "clang/Basic/Cuda.h" +#include "clang/Basic/SourceLocation.h" +#include "clang/Sema/Lookup.h" +#include "clang/Sema/Ownership.h" +#include "clang/Sema/ParsedAttr.h" +#include "clang/Sema/Scope.h" +#include "clang/Sema/ScopeInfo.h" +#include "clang/Sema/SemaBase.h" +#include "llvm/ADT/DenseMap.h" +#include "llvm/ADT/SmallVector.h" +#include <string> + +namespace clang { + +enum class CUDAFunctionTarget; + +class SemaCUDA : public SemaBase { +public: + SemaCUDA(Sema &S); + + /// Increments our count of the number of times we've seen a pragma forcing + /// functions to be __host__ __device__. So long as this count is greater + /// than zero, all functions encountered will be __host__ __device__. + void PushForceHostDevice(); + + /// Decrements our count of the number of times we've seen a pragma forcing + /// functions to be __host__ __device__. Returns false if the count is 0 + /// before incrementing, so you can emit an error. + bool PopForceHostDevice(); + + ExprResult ActOnExecConfigExpr(Scope *S, SourceLocation LLLLoc, + MultiExprArg ExecConfig, + SourceLocation GGGLoc); + + /// A pair of a canonical FunctionDecl and a SourceLocation. When used as the + /// key in a hashtable, both the FD and location are hashed. + struct FunctionDeclAndLoc { + CanonicalDeclPtr<const FunctionDecl> FD; + SourceLocation Loc; + }; + + /// FunctionDecls and SourceLocations for which CheckCall has emitted a + /// (maybe deferred) "bad call" diagnostic. We use this to avoid emitting the + /// same deferred diag twice. + llvm::DenseSet<FunctionDeclAndLoc> LocsWithCUDACallDiags; + + /// An inverse call graph, mapping known-emitted functions to one of their + /// known-emitted callers (plus the location of the call). + /// + /// Functions that we can tell a priori must be emitted aren't added to this + /// map. + llvm::DenseMap</* Callee = */ CanonicalDeclPtr<const FunctionDecl>, + /* Caller = */ FunctionDeclAndLoc> + DeviceKnownEmittedFns; + + /// Creates a SemaDiagnosticBuilder that emits the diagnostic if the current + /// context is "used as device code". + /// + /// - If CurContext is a __host__ function, does not emit any diagnostics + /// unless \p EmitOnBothSides is true. + /// - If CurContext is a __device__ or __global__ function, emits the + /// diagnostics immediately. + /// - If CurContext is a __host__ __device__ function and we are compiling for + /// the device, creates a diagnostic which is emitted if and when we realize + /// that the function will be codegen'ed. + /// + /// Example usage: + /// + /// // Variable-length arrays are not allowed in CUDA device code. + /// if (DiagIfDeviceCode(Loc, diag::err_cuda_vla) << CurrentTarget()) + /// return ExprError(); + /// // Otherwise, continue parsing as normal. + SemaDiagnosticBuilder DiagIfDeviceCode(SourceLocation Loc, unsigned DiagID); + + /// Creates a SemaDiagnosticBuilder that emits the diagnostic if the current + /// context is "used as host code". + /// + /// Same as DiagIfDeviceCode, with "host" and "device" switched. + SemaDiagnosticBuilder DiagIfHostCode(SourceLocation Loc, unsigned DiagID); + + /// Determines whether the given function is a CUDA device/host/kernel/etc. + /// function. + /// + /// Use this rather than examining the function's attributes yourself -- you + /// will get it wrong. Returns CUDAFunctionTarget::Host if D is null. + CUDAFunctionTarget IdentifyTarget(const FunctionDecl *D, + bool IgnoreImplicitHDAttr = false); + CUDAFunctionTarget IdentifyTarget(const ParsedAttributesView &Attrs); + + enum CUDAVariableTarget { + CVT_Device, /// Emitted on device side with a shadow variable on host side + CVT_Host, /// Emitted on host side only + CVT_Both, /// Emitted on both sides with different addresses + CVT_Unified, /// Emitted as a unified address, e.g. managed variables + }; + /// Determines whether the given variable is emitted on host or device side. + CUDAVariableTarget IdentifyTarget(const VarDecl *D); + + /// Defines kinds of CUDA global host/device context where a function may be + /// called. + enum CUDATargetContextKind { + CTCK_Unknown, /// Unknown context + CTCK_InitGlobalVar, /// Function called during global variable + /// initialization + }; + + /// Define the current global CUDA host/device context where a function may be + /// called. Only used when a function is called outside of any functions. + struct CUDATargetContext { + CUDAFunctionTarget Target = CUDAFunctionTarget::HostDevice; + CUDATargetContextKind Kind = CTCK_Unknown; + Decl *D = nullptr; + } CurCUDATargetCtx; + + struct CUDATargetContextRAII { + SemaCUDA &S; + SemaCUDA::CUDATargetContext SavedCtx; + CUDATargetContextRAII(SemaCUDA &S_, SemaCUDA::CUDATargetContextKind K, + Decl *D); + ~CUDATargetContextRAII() { S.CurCUDATargetCtx = SavedCtx; } + }; + + /// Gets the CUDA target for the current context. + CUDAFunctionTarget CurrentTarget() { + return IdentifyTarget(dyn_cast<FunctionDecl>(SemaRef.CurContext)); + } + + static bool isImplicitHostDeviceFunction(const FunctionDecl *D); + + // CUDA function call preference. Must be ordered numerically from + // worst to best. + enum CUDAFunctionPreference { + CFP_Never, // Invalid caller/callee combination. + CFP_WrongSide, // Calls from host-device to host or device + // function that do not match current compilation + // mode. + CFP_HostDevice, // Any calls to host/device functions. + CFP_SameSide, // Calls from host-device to host or device + // function matching current compilation mode. + CFP_Native, // host-to-host or device-to-device calls. + }; + + /// Identifies relative preference of a given Caller/Callee + /// combination, based on their host/device attributes. + /// \param Caller function which needs address of \p Callee. + /// nullptr in case of global context. + /// \param Callee target function + /// + /// \returns preference value for particular Caller/Callee combination. + CUDAFunctionPreference IdentifyPreference(const FunctionDecl *Caller, + const FunctionDecl *Callee); + + /// Determines whether Caller may invoke Callee, based on their CUDA + /// host/device attributes. Returns false if the call is not allowed. + /// + /// Note: Will return true for CFP_WrongSide calls. These may appear in + /// semantically correct CUDA programs, but only if they're never codegen'ed. + bool IsAllowedCall(const FunctionDecl *Caller, const FunctionDecl *Callee) { + return IdentifyPreference(Caller, Callee) != CFP_Never; + } + + /// May add implicit CUDAHostAttr and CUDADeviceAttr attributes to FD, + /// depending on FD and the current compilation settings. + void maybeAddHostDeviceAttrs(FunctionDecl *FD, const LookupResult &Previous); + + /// May add implicit CUDAConstantAttr attribute to VD, depending on VD + /// and current compilation settings. + void MaybeAddConstantAttr(VarDecl *VD); + + /// Check whether we're allowed to call Callee from the current context. + /// + /// - If the call is never allowed in a semantically-correct program + /// (CFP_Never), emits an error and returns false. + /// + /// - If the call is allowed in semantically-correct programs, but only if + /// it's never codegen'ed (CFP_WrongSide), creates a deferred diagnostic to + /// be emitted if and when the caller is codegen'ed, and returns true. + /// + /// Will only create deferred diagnostics for a given SourceLocation once, + /// so you can safely call this multiple times without generating duplicate + /// deferred errors. + /// + /// - Otherwise, returns true without emitting any diagnostics. + bool CheckCall(SourceLocation Loc, FunctionDecl *Callee); + + void CheckLambdaCapture(CXXMethodDecl *D, const sema::Capture &Capture); + + /// Set __device__ or __host__ __device__ attributes on the given lambda + /// operator() method. + /// + /// CUDA lambdas by default is host device function unless it has explicit + /// host or device attribute. + void SetLambdaAttrs(CXXMethodDecl *Method); + + /// Record \p FD if it is a CUDA/HIP implicit host device function used on + /// device side in device compilation. + void RecordImplicitHostDeviceFuncUsedByDevice(const FunctionDecl *FD); + + /// Finds a function in \p Matches with highest calling priority + /// from \p Caller context and erases all functions with lower + /// calling priority. + void EraseUnwantedMatches( + const FunctionDecl *Caller, + llvm::SmallVectorImpl<std::pair<DeclAccessPair, FunctionDecl *>> + &Matches); + + /// Given a implicit special member, infer its CUDA target from the + /// calls it needs to make to underlying base/field special members. + /// \param ClassDecl the class for which the member is being created. + /// \param CSM the kind of special member. + /// \param MemberDecl the special member itself. + /// \param ConstRHS true if this is a copy operation with a const object on + /// its RHS. + /// \param Diagnose true if this call should emit diagnostics. + /// \return true if there was an error inferring. + /// The result of this call is implicit CUDA target attribute(s) attached to + /// the member declaration. + bool inferTargetForImplicitSpecialMember(CXXRecordDecl *ClassDecl, + CXXSpecialMemberKind CSM, + CXXMethodDecl *MemberDecl, + bool ConstRHS, bool Diagnose); + + /// \return true if \p CD can be considered empty according to CUDA + /// (E.2.3.1 in CUDA 7.5 Programming guide). + bool isEmptyConstructor(SourceLocation Loc, CXXConstructorDecl *CD); + bool isEmptyDestructor(SourceLocation Loc, CXXDestructorDecl *CD); + + // \brief Checks that initializers of \p Var satisfy CUDA restrictions. In + // case of error emits appropriate diagnostic and invalidates \p Var. + // + // \details CUDA allows only empty constructors as initializers for global + // variables (see E.2.3.1, CUDA 7.5). The same restriction also applies to all + // __shared__ variables whether they are local or not (they all are implicitly + // static in CUDA). One exception is that CUDA allows constant initializers + // for __constant__ and __device__ variables. + void checkAllowedInitializer(VarDecl *VD); + + /// Check whether NewFD is a valid overload for CUDA. Emits + /// diagnostics and invalidates NewFD if not. + void checkTargetOverload(FunctionDecl *NewFD, const LookupResult &Previous); + /// Copies target attributes from the template TD to the function FD. + void inheritTargetAttrs(FunctionDecl *FD, const FunctionTemplateDecl &TD); + + /// Returns the name of the launch configuration function. This is the name + /// of the function that will be called to configure kernel call, with the + /// parameters specified via <<<>>>. + std::string getConfigureFuncName() const; + +private: + unsigned ForceHostDeviceDepth = 0; + + friend class ASTReader; + friend class ASTWriter; +}; + +} // namespace clang + +namespace llvm { +// Hash a FunctionDeclAndLoc by looking at both its FunctionDecl and its +// SourceLocation. +template <> struct DenseMapInfo<clang::SemaCUDA::FunctionDeclAndLoc> { + using FunctionDeclAndLoc = clang::SemaCUDA::FunctionDeclAndLoc; + using FDBaseInfo = + DenseMapInfo<clang::CanonicalDeclPtr<const clang::FunctionDecl>>; + + static FunctionDeclAndLoc getEmptyKey() { + return {FDBaseInfo::getEmptyKey(), clang::SourceLocation()}; + } + + static FunctionDeclAndLoc getTombstoneKey() { + return {FDBaseInfo::getTombstoneKey(), clang::SourceLocation()}; + } + + static unsigned getHashValue(const FunctionDeclAndLoc &FDL) { + return hash_combine(FDBaseInfo::getHashValue(FDL.FD), + FDL.Loc.getHashValue()); + } + + static bool isEqual(const FunctionDeclAndLoc &LHS, + const FunctionDeclAndLoc &RHS) { + return LHS.FD == RHS.FD && LHS.Loc == RHS.Loc; + } +}; +} // namespace llvm + +#endif // LLVM_CLANG_SEMA_SEMACUDA_H ---------------- Endilll wrote:
I always forget about it. Thank you! https://github.com/llvm/llvm-project/pull/88559 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
