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//==-- CGFunctionInfo.h - Representation of function argument/return types -==//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Defines CGFunctionInfo and associated types used in representing the
// LLVM source types and ABI-coerced types for function arguments and
// return values.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_CODEGEN_FUNCTION_INFO_H
#define LLVM_CLANG_CODEGEN_FUNCTION_INFO_H
#include "clang/AST/CanonicalType.h"
#include "clang/AST/Type.h"
#include "llvm/ADT/FoldingSet.h"
#include <cassert>
namespace llvm {
class Type;
class StructType;
}
namespace clang {
class Decl;
namespace CodeGen {
/// ABIArgInfo - Helper class to encapsulate information about how a
/// specific C type should be passed to or returned from a function.
class ABIArgInfo {
public:
enum Kind {
/// Direct - Pass the argument directly using the normal converted LLVM
/// type, or by coercing to another specified type stored in
/// 'CoerceToType'). If an offset is specified (in UIntData), then the
/// argument passed is offset by some number of bytes in the memory
/// representation. A dummy argument is emitted before the real argument
/// if the specified type stored in "PaddingType" is not zero.
Direct,
/// Extend - Valid only for integer argument types. Same as 'direct'
/// but also emit a zero/sign extension attribute.
Extend,
/// Indirect - Pass the argument indirectly via a hidden pointer
/// with the specified alignment (0 indicates default alignment).
Indirect,
/// Ignore - Ignore the argument (treat as void). Useful for void and
/// empty structs.
Ignore,
/// Expand - Only valid for aggregate argument types. The structure should
/// be expanded into consecutive arguments for its constituent fields.
/// Currently expand is only allowed on structures whose fields
/// are all scalar types or are themselves expandable types.
Expand,
/// InAlloca - Pass the argument directly using the LLVM inalloca attribute.
/// This is similar to 'direct', except it only applies to arguments stored
/// in memory and forbids any implicit copies. When applied to a return
/// type, it means the value is returned indirectly via an implicit sret
/// parameter stored in the argument struct.
InAlloca,
KindFirst = Direct,
KindLast = InAlloca
};
private:
Kind TheKind;
llvm::Type *TypeData;
llvm::Type *PaddingType;
unsigned UIntData;
bool BoolData0;
bool BoolData1;
bool InReg;
bool PaddingInReg;
ABIArgInfo(Kind K, llvm::Type *TD, unsigned UI, bool B0, bool B1, bool IR,
bool PIR, llvm::Type* P)
: TheKind(K), TypeData(TD), PaddingType(P), UIntData(UI), BoolData0(B0),
BoolData1(B1), InReg(IR), PaddingInReg(PIR) {}
public:
ABIArgInfo() : TheKind(Direct), TypeData(0), UIntData(0) {}
static ABIArgInfo getDirect(llvm::Type *T = 0, unsigned Offset = 0,
llvm::Type *Padding = 0) {
return ABIArgInfo(Direct, T, Offset, false, false, false, false, Padding);
}
static ABIArgInfo getDirectInReg(llvm::Type *T = 0) {
return ABIArgInfo(Direct, T, 0, false, false, true, false, 0);
}
static ABIArgInfo getExtend(llvm::Type *T = 0) {
return ABIArgInfo(Extend, T, 0, false, false, false, false, 0);
}
static ABIArgInfo getExtendInReg(llvm::Type *T = 0) {
return ABIArgInfo(Extend, T, 0, false, false, true, false, 0);
}
static ABIArgInfo getIgnore() {
return ABIArgInfo(Ignore, 0, 0, false, false, false, false, 0);
}
static ABIArgInfo getIndirect(unsigned Alignment, bool ByVal = true
, bool Realign = false
, llvm::Type *Padding = 0) {
return ABIArgInfo(Indirect, 0, Alignment, ByVal, Realign, false, false,
Padding);
}
static ABIArgInfo getInAlloca(unsigned FieldIndex) {
return ABIArgInfo(InAlloca, 0, FieldIndex, false, false, false, false, 0);
}
static ABIArgInfo getIndirectInReg(unsigned Alignment, bool ByVal = true
, bool Realign = false) {
return ABIArgInfo(Indirect, 0, Alignment, ByVal, Realign, true, false, 0);
}
static ABIArgInfo getExpand() {
return ABIArgInfo(Expand, 0, 0, false, false, false, false, 0);
}
static ABIArgInfo getExpandWithPadding(bool PaddingInReg,
llvm::Type *Padding) {
return ABIArgInfo(Expand, 0, 0, false, false, false, PaddingInReg,
Padding);
}
Kind getKind() const { return TheKind; }
bool isDirect() const { return TheKind == Direct; }
bool isInAlloca() const { return TheKind == InAlloca; }
bool isExtend() const { return TheKind == Extend; }
bool isIgnore() const { return TheKind == Ignore; }
bool isIndirect() const { return TheKind == Indirect; }
bool isExpand() const { return TheKind == Expand; }
bool canHaveCoerceToType() const {
return TheKind == Direct || TheKind == Extend;
}
// Direct/Extend accessors
unsigned getDirectOffset() const {
assert((isDirect() || isExtend()) && "Not a direct or extend kind");
return UIntData;
}
llvm::Type *getPaddingType() const {
return PaddingType;
}
void setPaddingType(llvm::Type *T) {
PaddingType = T;
}
bool getPaddingInReg() const {
return PaddingInReg;
}
llvm::Type *getCoerceToType() const {
assert(canHaveCoerceToType() && "Invalid kind!");
return TypeData;
}
void setCoerceToType(llvm::Type *T) {
assert(canHaveCoerceToType() && "Invalid kind!");
TypeData = T;
}
bool getInReg() const {
assert((isDirect() || isExtend() || isIndirect()) && "Invalid kind!");
return InReg;
}
// Indirect accessors
unsigned getIndirectAlign() const {
assert(TheKind == Indirect && "Invalid kind!");
return UIntData;
}
bool getIndirectByVal() const {
assert(TheKind == Indirect && "Invalid kind!");
return BoolData0;
}
bool getIndirectRealign() const {
assert(TheKind == Indirect && "Invalid kind!");
return BoolData1;
}
unsigned getInAllocaFieldIndex() const {
assert(TheKind == InAlloca && "Invalid kind!");
return UIntData;
}
/// \brief Return true if this field of an inalloca struct should be returned
/// to implement a struct return calling convention.
bool getInAllocaSRet() const {
assert(TheKind == InAlloca && "Invalid kind!");
return BoolData0;
}
void setInAllocaSRet(bool SRet) {
assert(TheKind == InAlloca && "Invalid kind!");
BoolData0 = SRet;
}
void dump() const;
};
/// A class for recording the number of arguments that a function
/// signature requires.
class RequiredArgs {
/// The number of required arguments, or ~0 if the signature does
/// not permit optional arguments.
unsigned NumRequired;
public:
enum All_t { All };
RequiredArgs(All_t _) : NumRequired(~0U) {}
explicit RequiredArgs(unsigned n) : NumRequired(n) {
assert(n != ~0U);
}
/// Compute the arguments required by the given formal prototype,
/// given that there may be some additional, non-formal arguments
/// in play.
static RequiredArgs forPrototypePlus(const FunctionProtoType *prototype,
unsigned additional) {
if (!prototype->isVariadic()) return All;
return RequiredArgs(prototype->getNumParams() + additional);
}
static RequiredArgs forPrototype(const FunctionProtoType *prototype) {
return forPrototypePlus(prototype, 0);
}
static RequiredArgs forPrototype(CanQual<FunctionProtoType> prototype) {
return forPrototype(prototype.getTypePtr());
}
static RequiredArgs forPrototypePlus(CanQual<FunctionProtoType> prototype,
unsigned additional) {
return forPrototypePlus(prototype.getTypePtr(), additional);
}
bool allowsOptionalArgs() const { return NumRequired != ~0U; }
unsigned getNumRequiredArgs() const {
assert(allowsOptionalArgs());
return NumRequired;
}
unsigned getOpaqueData() const { return NumRequired; }
static RequiredArgs getFromOpaqueData(unsigned value) {
if (value == ~0U) return All;
return RequiredArgs(value);
}
};
/// CGFunctionInfo - Class to encapsulate the information about a
/// function definition.
class CGFunctionInfo : public llvm::FoldingSetNode {
struct ArgInfo {
CanQualType type;
ABIArgInfo info;
};
/// The LLVM::CallingConv to use for this function (as specified by the
/// user).
unsigned CallingConvention : 8;
/// The LLVM::CallingConv to actually use for this function, which may
/// depend on the ABI.
unsigned EffectiveCallingConvention : 8;
/// The clang::CallingConv that this was originally created with.
unsigned ASTCallingConvention : 8;
/// Whether this is an instance method.
unsigned InstanceMethod : 1;
/// Whether this function is noreturn.
unsigned NoReturn : 1;
/// Whether this function is returns-retained.
unsigned ReturnsRetained : 1;
/// How many arguments to pass inreg.
unsigned HasRegParm : 1;
unsigned RegParm : 4;
RequiredArgs Required;
/// The struct representing all arguments passed in memory. Only used when
/// passing non-trivial types with inalloca. Not part of the profile.
llvm::StructType *ArgStruct;
unsigned NumArgs;
ArgInfo *getArgsBuffer() {
return reinterpret_cast<ArgInfo*>(this+1);
}
const ArgInfo *getArgsBuffer() const {
return reinterpret_cast<const ArgInfo*>(this + 1);
}
CGFunctionInfo() : Required(RequiredArgs::All) {}
public:
static CGFunctionInfo *create(unsigned llvmCC,
bool InstanceMethod,
const FunctionType::ExtInfo &extInfo,
CanQualType resultType,
ArrayRef<CanQualType> argTypes,
RequiredArgs required);
typedef const ArgInfo *const_arg_iterator;
typedef ArgInfo *arg_iterator;
typedef llvm::iterator_range<arg_iterator> arg_range;
typedef llvm::iterator_range<const_arg_iterator> arg_const_range;
arg_range arguments() { return arg_range(arg_begin(), arg_end()); }
arg_const_range arguments() const {
return arg_const_range(arg_begin(), arg_end());
}
const_arg_iterator arg_begin() const { return getArgsBuffer() + 1; }
const_arg_iterator arg_end() const { return getArgsBuffer() + 1 + NumArgs; }
arg_iterator arg_begin() { return getArgsBuffer() + 1; }
arg_iterator arg_end() { return getArgsBuffer() + 1 + NumArgs; }
unsigned arg_size() const { return NumArgs; }
bool isVariadic() const { return Required.allowsOptionalArgs(); }
RequiredArgs getRequiredArgs() const { return Required; }
bool isInstanceMethod() const { return InstanceMethod; }
bool isNoReturn() const { return NoReturn; }
/// In ARC, whether this function retains its return value. This
/// is not always reliable for call sites.
bool isReturnsRetained() const { return ReturnsRetained; }
/// getASTCallingConvention() - Return the AST-specified calling
/// convention.
CallingConv getASTCallingConvention() const {
return CallingConv(ASTCallingConvention);
}
/// getCallingConvention - Return the user specified calling
/// convention, which has been translated into an LLVM CC.
unsigned getCallingConvention() const { return CallingConvention; }
/// getEffectiveCallingConvention - Return the actual calling convention to
/// use, which may depend on the ABI.
unsigned getEffectiveCallingConvention() const {
return EffectiveCallingConvention;
}
void setEffectiveCallingConvention(unsigned Value) {
EffectiveCallingConvention = Value;
}
bool getHasRegParm() const { return HasRegParm; }
unsigned getRegParm() const { return RegParm; }
FunctionType::ExtInfo getExtInfo() const {
return FunctionType::ExtInfo(isNoReturn(),
getHasRegParm(), getRegParm(),
getASTCallingConvention(),
isReturnsRetained());
}
CanQualType getReturnType() const { return getArgsBuffer()[0].type; }
ABIArgInfo &getReturnInfo() { return getArgsBuffer()[0].info; }
const ABIArgInfo &getReturnInfo() const { return getArgsBuffer()[0].info; }
/// \brief Return true if this function uses inalloca arguments.
bool usesInAlloca() const { return ArgStruct; }
/// \brief Get the struct type used to represent all the arguments in memory.
llvm::StructType *getArgStruct() const { return ArgStruct; }
void setArgStruct(llvm::StructType *Ty) { ArgStruct = Ty; }
void Profile(llvm::FoldingSetNodeID &ID) {
ID.AddInteger(getASTCallingConvention());
ID.AddBoolean(InstanceMethod);
ID.AddBoolean(NoReturn);
ID.AddBoolean(ReturnsRetained);
ID.AddBoolean(HasRegParm);
ID.AddInteger(RegParm);
ID.AddInteger(Required.getOpaqueData());
getReturnType().Profile(ID);
for (const auto &I : arguments())
I.type.Profile(ID);
}
static void Profile(llvm::FoldingSetNodeID &ID,
bool InstanceMethod,
const FunctionType::ExtInfo &info,
RequiredArgs required,
CanQualType resultType,
ArrayRef<CanQualType> argTypes) {
ID.AddInteger(info.getCC());
ID.AddBoolean(InstanceMethod);
ID.AddBoolean(info.getNoReturn());
ID.AddBoolean(info.getProducesResult());
ID.AddBoolean(info.getHasRegParm());
ID.AddInteger(info.getRegParm());
ID.AddInteger(required.getOpaqueData());
resultType.Profile(ID);
for (ArrayRef<CanQualType>::iterator
i = argTypes.begin(), e = argTypes.end(); i != e; ++i) {
i->Profile(ID);
}
}
};
} // end namespace CodeGen
} // end namespace clang
#endif