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//===----- ABIInfo.h - ABI information access & encapsulation ---*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef CLANG_CODEGEN_ABIINFO_H
#define CLANG_CODEGEN_ABIINFO_H
#include "clang/AST/Type.h"
#include "llvm/Type.h"
namespace llvm {
class Value;
class LLVMContext;
class TargetData;
}
namespace clang {
class ASTContext;
namespace CodeGen {
class CGFunctionInfo;
class CodeGenFunction;
class CodeGenTypes;
}
// FIXME: All of this stuff should be part of the target interface
// somehow. It is currently here because it is not clear how to factor
// the targets to support this, since the Targets currently live in a
// layer below types n'stuff.
/// 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,
KindFirst=Direct, KindLast=Expand
};
private:
Kind TheKind;
llvm::Type *TypeData;
llvm::Type *PaddingType; // Currently allowed only for Direct.
unsigned UIntData;
bool BoolData0;
bool BoolData1;
ABIArgInfo(Kind K, llvm::Type *TD, unsigned UI, bool B0, bool B1,
llvm::Type* P)
: TheKind(K), TypeData(TD), PaddingType(P), UIntData(UI), BoolData0(B0),
BoolData1(B1) {}
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, Padding);
}
static ABIArgInfo getExtend(llvm::Type *T = 0) {
return ABIArgInfo(Extend, T, 0, false, false, 0);
}
static ABIArgInfo getIgnore() {
return ABIArgInfo(Ignore, 0, 0, false, false, 0);
}
static ABIArgInfo getIndirect(unsigned Alignment, bool ByVal = true
, bool Realign = false) {
return ABIArgInfo(Indirect, 0, Alignment, ByVal, Realign, 0);
}
static ABIArgInfo getExpand() {
return ABIArgInfo(Expand, 0, 0, false, false, 0);
}
Kind getKind() const { return TheKind; }
bool isDirect() const { return TheKind == Direct; }
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;
}
llvm::Type *getCoerceToType() const {
assert(canHaveCoerceToType() && "Invalid kind!");
return TypeData;
}
void setCoerceToType(llvm::Type *T) {
assert(canHaveCoerceToType() && "Invalid kind!");
TypeData = T;
}
// 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;
}
void dump() const;
};
/// ABIInfo - Target specific hooks for defining how a type should be
/// passed or returned from functions.
class ABIInfo {
public:
CodeGen::CodeGenTypes &CGT;
ABIInfo(CodeGen::CodeGenTypes &cgt) : CGT(cgt) {}
virtual ~ABIInfo();
ASTContext &getContext() const;
llvm::LLVMContext &getVMContext() const;
const llvm::TargetData &getTargetData() const;
virtual void computeInfo(CodeGen::CGFunctionInfo &FI) const = 0;
/// EmitVAArg - Emit the target dependent code to load a value of
/// \arg Ty from the va_list pointed to by \arg VAListAddr.
// FIXME: This is a gaping layering violation if we wanted to drop
// the ABI information any lower than CodeGen. Of course, for
// VAArg handling it has to be at this level; there is no way to
// abstract this out.
virtual llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
CodeGen::CodeGenFunction &CGF) const = 0;
};
} // end namespace clang
#endif