diff options
Diffstat (limited to 'lib/CodeGen/TargetInfo.h')
| -rw-r--r-- | lib/CodeGen/TargetInfo.h | 360 |
1 files changed, 185 insertions, 175 deletions
diff --git a/lib/CodeGen/TargetInfo.h b/lib/CodeGen/TargetInfo.h index f631f3102d0d1..2616820185f55 100644 --- a/lib/CodeGen/TargetInfo.h +++ b/lib/CodeGen/TargetInfo.h @@ -17,189 +17,199 @@ #include "clang/AST/Type.h" #include "clang/Basic/LLVM.h" -#include "llvm/ADT/StringRef.h" #include "llvm/ADT/SmallString.h" +#include "llvm/ADT/StringRef.h" namespace llvm { - class Constant; - class GlobalValue; - class Type; - class Value; +class Constant; +class GlobalValue; +class Type; +class Value; } namespace clang { - class ABIInfo; - class Decl; - - namespace CodeGen { - class CallArgList; - class CodeGenModule; - class CodeGenFunction; - class CGFunctionInfo; +class ABIInfo; +class Decl; + +namespace CodeGen { +class CallArgList; +class CodeGenModule; +class CodeGenFunction; +class CGFunctionInfo; +} + +/// TargetCodeGenInfo - This class organizes various target-specific +/// codegeneration issues, like target-specific attributes, builtins and so +/// on. +class TargetCodeGenInfo { + ABIInfo *Info; + +public: + // WARNING: Acquires the ownership of ABIInfo. + TargetCodeGenInfo(ABIInfo *info = 0) : Info(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 {} + + /// EmitTargetMD - Provides a convenient hook to handle extra + /// target-specific metadata for the given global. + virtual void emitTargetMD(const Decl *D, llvm::GlobalValue *GV, + CodeGen::CodeGenModule &M) 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; + } + + /// 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 ""; + } + + /// 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; } - /// TargetCodeGenInfo - This class organizes various target-specific - /// codegeneration issues, like target-specific attributes, builtins and so - /// on. - class TargetCodeGenInfo { - ABIInfo *Info; - public: - // WARNING: Acquires the ownership of ABIInfo. - TargetCodeGenInfo(ABIInfo *info = 0):Info(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 { } - - /// 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; - } - - /// 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 ""; - } - - /// 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 0; - } - - /// 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 desireable 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 {} - }; + /// 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 {} +}; } #endif // CLANG_CODEGEN_TARGETINFO_H |