llvm-project/clang/lib/CodeGen/CGCall.h

307 lines
9.8 KiB
C++

//===----- CGCall.h - Encapsulate calling convention details ----*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// These classes wrap the information about a call or function
// definition used to handle ABI compliancy.
//
//===----------------------------------------------------------------------===//
#ifndef CLANG_CODEGEN_CGCALL_H
#define CLANG_CODEGEN_CGCALL_H
#include "llvm/ADT/FoldingSet.h"
#include "llvm/Value.h"
#include "clang/AST/Type.h"
#include "clang/AST/CanonicalType.h"
#include "CGValue.h"
// FIXME: Restructure so we don't have to expose so much stuff.
#include "ABIInfo.h"
namespace llvm {
struct AttributeWithIndex;
class Function;
class Type;
class Value;
template<typename T, unsigned> class SmallVector;
}
namespace clang {
class ASTContext;
class Decl;
class FunctionDecl;
class ObjCMethodDecl;
class VarDecl;
namespace CodeGen {
typedef SmallVector<llvm::AttributeWithIndex, 8> AttributeListType;
struct CallArg {
RValue RV;
QualType Ty;
bool NeedsCopy;
CallArg(RValue rv, QualType ty, bool needscopy)
: RV(rv), Ty(ty), NeedsCopy(needscopy)
{ }
};
/// CallArgList - Type for representing both the value and type of
/// arguments in a call.
class CallArgList :
public SmallVector<CallArg, 16> {
public:
struct Writeback {
/// The original argument.
llvm::Value *Address;
/// The pointee type of the original argument.
QualType AddressType;
/// The temporary alloca.
llvm::Value *Temporary;
};
void add(RValue rvalue, QualType type, bool needscopy = false) {
push_back(CallArg(rvalue, type, needscopy));
}
void addFrom(const CallArgList &other) {
insert(end(), other.begin(), other.end());
Writebacks.insert(Writebacks.end(),
other.Writebacks.begin(), other.Writebacks.end());
}
void addWriteback(llvm::Value *address, QualType addressType,
llvm::Value *temporary) {
Writeback writeback;
writeback.Address = address;
writeback.AddressType = addressType;
writeback.Temporary = temporary;
Writebacks.push_back(writeback);
}
bool hasWritebacks() const { return !Writebacks.empty(); }
typedef SmallVectorImpl<Writeback>::const_iterator writeback_iterator;
writeback_iterator writeback_begin() const { return Writebacks.begin(); }
writeback_iterator writeback_end() const { return Writebacks.end(); }
private:
SmallVector<Writeback, 1> Writebacks;
};
/// 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->getNumArgs() + 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; }
bool getNumRequiredArgs() const {
assert(allowsOptionalArgs());
return NumRequired;
}
unsigned getOpaqueData() const { return NumRequired; }
static RequiredArgs getFromOpaqueData(unsigned value) {
if (value == ~0U) return All;
return RequiredArgs(value);
}
};
/// FunctionArgList - Type for representing both the decl and type
/// of parameters to a function. The decl must be either a
/// ParmVarDecl or ImplicitParamDecl.
class FunctionArgList : public SmallVector<const VarDecl*, 16> {
};
/// 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 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;
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,
const FunctionType::ExtInfo &extInfo,
CanQualType resultType,
ArrayRef<CanQualType> argTypes,
RequiredArgs required);
typedef const ArgInfo *const_arg_iterator;
typedef ArgInfo *arg_iterator;
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 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; }
void Profile(llvm::FoldingSetNodeID &ID) {
ID.AddInteger(getASTCallingConvention());
ID.AddBoolean(NoReturn);
ID.AddBoolean(ReturnsRetained);
ID.AddBoolean(HasRegParm);
ID.AddInteger(RegParm);
ID.AddInteger(Required.getOpaqueData());
getReturnType().Profile(ID);
for (arg_iterator it = arg_begin(), ie = arg_end(); it != ie; ++it)
it->type.Profile(ID);
}
static void Profile(llvm::FoldingSetNodeID &ID,
const FunctionType::ExtInfo &info,
RequiredArgs required,
CanQualType resultType,
ArrayRef<CanQualType> argTypes) {
ID.AddInteger(info.getCC());
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);
}
}
};
/// ReturnValueSlot - Contains the address where the return value of a
/// function can be stored, and whether the address is volatile or not.
class ReturnValueSlot {
llvm::PointerIntPair<llvm::Value *, 1, bool> Value;
public:
ReturnValueSlot() {}
ReturnValueSlot(llvm::Value *Value, bool IsVolatile)
: Value(Value, IsVolatile) {}
bool isNull() const { return !getValue(); }
bool isVolatile() const { return Value.getInt(); }
llvm::Value *getValue() const { return Value.getPointer(); }
};
} // end namespace CodeGen
} // end namespace clang
#endif