| //===---- TargetInfo.h - Encapsulate target details -------------*- C++ -*-===// |
| // |
| // 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 |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // These classes wrap the information about a call or function |
| // definition used to handle ABI compliancy. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_CLANG_LIB_CODEGEN_TARGETINFO_H |
| #define LLVM_CLANG_LIB_CODEGEN_TARGETINFO_H |
| |
| #include "CodeGenModule.h" |
| #include "CGValue.h" |
| #include "clang/AST/Type.h" |
| #include "clang/Basic/LLVM.h" |
| #include "clang/Basic/SyncScope.h" |
| #include "llvm/ADT/SmallString.h" |
| #include "llvm/ADT/StringRef.h" |
| |
| namespace llvm { |
| class Constant; |
| class GlobalValue; |
| class Type; |
| class Value; |
| } |
| |
| namespace clang { |
| class Decl; |
| |
| namespace CodeGen { |
| class ABIInfo; |
| class CallArgList; |
| class CodeGenFunction; |
| class CGBlockInfo; |
| class CGFunctionInfo; |
| |
| /// TargetCodeGenInfo - This class organizes various target-specific |
| /// codegeneration issues, like target-specific attributes, builtins and so |
| /// on. |
| class TargetCodeGenInfo { |
| std::unique_ptr<ABIInfo> Info = nullptr; |
| |
| public: |
| TargetCodeGenInfo(std::unique_ptr<ABIInfo> Info) : Info(std::move(Info)) {} |
| virtual ~TargetCodeGenInfo(); |
| |
| /// getABIInfo() - Returns ABI info helper for the target. |
| const ABIInfo &getABIInfo() const { return *Info; } |
| |
| /// setTargetAttributes - Provides a convenient hook to handle extra |
| /// target-specific attributes for the given global. |
| virtual void setTargetAttributes(const Decl *D, llvm::GlobalValue *GV, |
| CodeGen::CodeGenModule &M) const {} |
| |
| /// emitTargetMetadata - Provides a convenient hook to handle extra |
| /// target-specific metadata for the given globals. |
| virtual void emitTargetMetadata( |
| CodeGen::CodeGenModule &CGM, |
| const llvm::MapVector<GlobalDecl, StringRef> &MangledDeclNames) const {} |
| |
| /// Any further codegen related checks that need to be done on a function call |
| /// in a target specific manner. |
| virtual void checkFunctionCallABI(CodeGenModule &CGM, SourceLocation CallLoc, |
| const FunctionDecl *Caller, |
| const FunctionDecl *Callee, |
| const CallArgList &Args) const {} |
| |
| /// Determines the size of struct _Unwind_Exception on this platform, |
| /// in 8-bit units. The Itanium ABI defines this as: |
| /// struct _Unwind_Exception { |
| /// uint64 exception_class; |
| /// _Unwind_Exception_Cleanup_Fn exception_cleanup; |
| /// uint64 private_1; |
| /// uint64 private_2; |
| /// }; |
| virtual unsigned getSizeOfUnwindException() const; |
| |
| /// Controls whether __builtin_extend_pointer should sign-extend |
| /// pointers to uint64_t or zero-extend them (the default). Has |
| /// no effect for targets: |
| /// - that have 64-bit pointers, or |
| /// - that cannot address through registers larger than pointers, or |
| /// - that implicitly ignore/truncate the top bits when addressing |
| /// through such registers. |
| virtual bool extendPointerWithSExt() const { return false; } |
| |
| /// Determines the DWARF register number for the stack pointer, for |
| /// exception-handling purposes. Implements __builtin_dwarf_sp_column. |
| /// |
| /// Returns -1 if the operation is unsupported by this target. |
| virtual int getDwarfEHStackPointer(CodeGen::CodeGenModule &M) const { |
| return -1; |
| } |
| |
| /// Initializes the given DWARF EH register-size table, a char*. |
| /// Implements __builtin_init_dwarf_reg_size_table. |
| /// |
| /// Returns true if the operation is unsupported by this target. |
| virtual bool initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF, |
| llvm::Value *Address) const { |
| return true; |
| } |
| |
| /// Performs the code-generation required to convert a return |
| /// address as stored by the system into the actual address of the |
| /// next instruction that will be executed. |
| /// |
| /// Used by __builtin_extract_return_addr(). |
| virtual llvm::Value *decodeReturnAddress(CodeGen::CodeGenFunction &CGF, |
| llvm::Value *Address) const { |
| return Address; |
| } |
| |
| /// Performs the code-generation required to convert the address |
| /// of an instruction into a return address suitable for storage |
| /// by the system in a return slot. |
| /// |
| /// Used by __builtin_frob_return_addr(). |
| virtual llvm::Value *encodeReturnAddress(CodeGen::CodeGenFunction &CGF, |
| llvm::Value *Address) const { |
| return Address; |
| } |
| |
| /// Corrects the low-level LLVM type for a given constraint and "usual" |
| /// type. |
| /// |
| /// \returns A pointer to a new LLVM type, possibly the same as the original |
| /// on success; 0 on failure. |
| virtual llvm::Type *adjustInlineAsmType(CodeGen::CodeGenFunction &CGF, |
| StringRef Constraint, |
| llvm::Type *Ty) const { |
| return Ty; |
| } |
| |
| /// Adds constraints and types for result registers. |
| virtual void addReturnRegisterOutputs( |
| CodeGen::CodeGenFunction &CGF, CodeGen::LValue ReturnValue, |
| std::string &Constraints, std::vector<llvm::Type *> &ResultRegTypes, |
| std::vector<llvm::Type *> &ResultTruncRegTypes, |
| std::vector<CodeGen::LValue> &ResultRegDests, std::string &AsmString, |
| unsigned NumOutputs) const {} |
| |
| /// doesReturnSlotInterfereWithArgs - Return true if the target uses an |
| /// argument slot for an 'sret' type. |
| virtual bool doesReturnSlotInterfereWithArgs() const { return true; } |
| |
| /// Retrieve the address of a function to call immediately before |
| /// calling objc_retainAutoreleasedReturnValue. The |
| /// implementation of objc_autoreleaseReturnValue sniffs the |
| /// instruction stream following its return address to decide |
| /// whether it's a call to objc_retainAutoreleasedReturnValue. |
| /// This can be prohibitively expensive, depending on the |
| /// relocation model, and so on some targets it instead sniffs for |
| /// a particular instruction sequence. This functions returns |
| /// that instruction sequence in inline assembly, which will be |
| /// empty if none is required. |
| virtual StringRef getARCRetainAutoreleasedReturnValueMarker() const { |
| return ""; |
| } |
| |
| /// Determine whether a call to objc_retainAutoreleasedReturnValue or |
| /// objc_unsafeClaimAutoreleasedReturnValue should be marked as 'notail'. |
| virtual bool markARCOptimizedReturnCallsAsNoTail() const { return false; } |
| |
| /// Return a constant used by UBSan as a signature to identify functions |
| /// possessing type information, or 0 if the platform is unsupported. |
| virtual llvm::Constant * |
| getUBSanFunctionSignature(CodeGen::CodeGenModule &CGM) const { |
| return nullptr; |
| } |
| |
| /// Determine whether a call to an unprototyped functions under |
| /// the given calling convention should use the variadic |
| /// convention or the non-variadic convention. |
| /// |
| /// There's a good reason to make a platform's variadic calling |
| /// convention be different from its non-variadic calling |
| /// convention: the non-variadic arguments can be passed in |
| /// registers (better for performance), and the variadic arguments |
| /// can be passed on the stack (also better for performance). If |
| /// this is done, however, unprototyped functions *must* use the |
| /// non-variadic convention, because C99 states that a call |
| /// through an unprototyped function type must succeed if the |
| /// function was defined with a non-variadic prototype with |
| /// compatible parameters. Therefore, splitting the conventions |
| /// makes it impossible to call a variadic function through an |
| /// unprototyped type. Since function prototypes came out in the |
| /// late 1970s, this is probably an acceptable trade-off. |
| /// Nonetheless, not all platforms are willing to make it, and in |
| /// particularly x86-64 bends over backwards to make the |
| /// conventions compatible. |
| /// |
| /// The default is false. This is correct whenever: |
| /// - the conventions are exactly the same, because it does not |
| /// matter and the resulting IR will be somewhat prettier in |
| /// certain cases; or |
| /// - the conventions are substantively different in how they pass |
| /// arguments, because in this case using the variadic convention |
| /// will lead to C99 violations. |
| /// |
| /// However, some platforms make the conventions identical except |
| /// for passing additional out-of-band information to a variadic |
| /// function: for example, x86-64 passes the number of SSE |
| /// arguments in %al. On these platforms, it is desirable to |
| /// call unprototyped functions using the variadic convention so |
| /// that unprototyped calls to varargs functions still succeed. |
| /// |
| /// Relatedly, platforms which pass the fixed arguments to this: |
| /// A foo(B, C, D); |
| /// differently than they would pass them to this: |
| /// A foo(B, C, D, ...); |
| /// may need to adjust the debugger-support code in Sema to do the |
| /// right thing when calling a function with no know signature. |
| virtual bool isNoProtoCallVariadic(const CodeGen::CallArgList &args, |
| const FunctionNoProtoType *fnType) const; |
| |
| /// Gets the linker options necessary to link a dependent library on this |
| /// platform. |
| virtual void getDependentLibraryOption(llvm::StringRef Lib, |
| llvm::SmallString<24> &Opt) const; |
| |
| /// Gets the linker options necessary to detect object file mismatches on |
| /// this platform. |
| virtual void getDetectMismatchOption(llvm::StringRef Name, |
| llvm::StringRef Value, |
| llvm::SmallString<32> &Opt) const {} |
| |
| /// Get LLVM calling convention for OpenCL kernel. |
| virtual unsigned getOpenCLKernelCallingConv() const; |
| |
| /// Get target specific null pointer. |
| /// \param T is the LLVM type of the null pointer. |
| /// \param QT is the clang QualType of the null pointer. |
| /// \return ConstantPointerNull with the given type \p T. |
| /// Each target can override it to return its own desired constant value. |
| virtual llvm::Constant *getNullPointer(const CodeGen::CodeGenModule &CGM, |
| llvm::PointerType *T, QualType QT) const; |
| |
| /// Get target favored AST address space of a global variable for languages |
| /// other than OpenCL and CUDA. |
| /// If \p D is nullptr, returns the default target favored address space |
| /// for global variable. |
| virtual LangAS getGlobalVarAddressSpace(CodeGenModule &CGM, |
| const VarDecl *D) const; |
| |
| /// Get the AST address space for alloca. |
| virtual LangAS getASTAllocaAddressSpace() const { return LangAS::Default; } |
| |
| /// Perform address space cast of an expression of pointer type. |
| /// \param V is the LLVM value to be casted to another address space. |
| /// \param SrcAddr is the language address space of \p V. |
| /// \param DestAddr is the targeted language address space. |
| /// \param DestTy is the destination LLVM pointer type. |
| /// \param IsNonNull is the flag indicating \p V is known to be non null. |
| virtual llvm::Value *performAddrSpaceCast(CodeGen::CodeGenFunction &CGF, |
| llvm::Value *V, LangAS SrcAddr, |
| LangAS DestAddr, llvm::Type *DestTy, |
| bool IsNonNull = false) const; |
| |
| /// Perform address space cast of a constant expression of pointer type. |
| /// \param V is the LLVM constant to be casted to another address space. |
| /// \param SrcAddr is the language address space of \p V. |
| /// \param DestAddr is the targeted language address space. |
| /// \param DestTy is the destination LLVM pointer type. |
| virtual llvm::Constant *performAddrSpaceCast(CodeGenModule &CGM, |
| llvm::Constant *V, |
| LangAS SrcAddr, LangAS DestAddr, |
| llvm::Type *DestTy) const; |
| |
| /// Get address space of pointer parameter for __cxa_atexit. |
| virtual LangAS getAddrSpaceOfCxaAtexitPtrParam() const { |
| return LangAS::Default; |
| } |
| |
| /// Get the syncscope used in LLVM IR. |
| virtual llvm::SyncScope::ID getLLVMSyncScopeID(const LangOptions &LangOpts, |
| SyncScope Scope, |
| llvm::AtomicOrdering Ordering, |
| llvm::LLVMContext &Ctx) const; |
| |
| /// Interface class for filling custom fields of a block literal for OpenCL. |
| class TargetOpenCLBlockHelper { |
| public: |
| typedef std::pair<llvm::Value *, StringRef> ValueTy; |
| TargetOpenCLBlockHelper() {} |
| virtual ~TargetOpenCLBlockHelper() {} |
| /// Get the custom field types for OpenCL blocks. |
| virtual llvm::SmallVector<llvm::Type *, 1> getCustomFieldTypes() = 0; |
| /// Get the custom field values for OpenCL blocks. |
| virtual llvm::SmallVector<ValueTy, 1> |
| getCustomFieldValues(CodeGenFunction &CGF, const CGBlockInfo &Info) = 0; |
| virtual bool areAllCustomFieldValuesConstant(const CGBlockInfo &Info) = 0; |
| /// Get the custom field values for OpenCL blocks if all values are LLVM |
| /// constants. |
| virtual llvm::SmallVector<llvm::Constant *, 1> |
| getCustomFieldValues(CodeGenModule &CGM, const CGBlockInfo &Info) = 0; |
| }; |
| virtual TargetOpenCLBlockHelper *getTargetOpenCLBlockHelper() const { |
| return nullptr; |
| } |
| |
| /// Create an OpenCL kernel for an enqueued block. The kernel function is |
| /// a wrapper for the block invoke function with target-specific calling |
| /// convention and ABI as an OpenCL kernel. The wrapper function accepts |
| /// block context and block arguments in target-specific way and calls |
| /// the original block invoke function. |
| virtual llvm::Function * |
| createEnqueuedBlockKernel(CodeGenFunction &CGF, |
| llvm::Function *BlockInvokeFunc, |
| llvm::Value *BlockLiteral) const; |
| |
| /// \return true if the target supports alias from the unmangled name to the |
| /// mangled name of functions declared within an extern "C" region and marked |
| /// as 'used', and having internal linkage. |
| virtual bool shouldEmitStaticExternCAliases() const { return true; } |
| |
| virtual void setCUDAKernelCallingConvention(const FunctionType *&FT) const {} |
| |
| /// Return the device-side type for the CUDA device builtin surface type. |
| virtual llvm::Type *getCUDADeviceBuiltinSurfaceDeviceType() const { |
| // By default, no change from the original one. |
| return nullptr; |
| } |
| /// Return the device-side type for the CUDA device builtin texture type. |
| virtual llvm::Type *getCUDADeviceBuiltinTextureDeviceType() const { |
| // By default, no change from the original one. |
| return nullptr; |
| } |
| |
| /// Emit the device-side copy of the builtin surface type. |
| virtual bool emitCUDADeviceBuiltinSurfaceDeviceCopy(CodeGenFunction &CGF, |
| LValue Dst, |
| LValue Src) const { |
| // DO NOTHING by default. |
| return false; |
| } |
| /// Emit the device-side copy of the builtin texture type. |
| virtual bool emitCUDADeviceBuiltinTextureDeviceCopy(CodeGenFunction &CGF, |
| LValue Dst, |
| LValue Src) const { |
| // DO NOTHING by default. |
| return false; |
| } |
| }; |
| |
| } // namespace CodeGen |
| } // namespace clang |
| |
| #endif // LLVM_CLANG_LIB_CODEGEN_TARGETINFO_H |