Reid Kleckner 23f4c4b64f [ms-cxxabi] Destroy temporary record arguments in the callee
Itanium destroys them in the caller at the end of the full expression,
but MSVC destroys them in the callee.  This is further complicated by
the need to emit EH-only destructor cleanups in the caller.

This should help clang compile MSVC's debug iterators more correctly.
There is still an outstanding issue in PR5064 of a memcpy emitted by the
LLVM backend, which is not correct for C++ records.

Fixes PR16226.

Reviewers: rjmccall

Differential Revision: http://llvm-reviews.chandlerc.com/D929

llvm-svn: 184543
2013-06-21 12:45:15 +00:00

331 lines
11 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 "CGValue.h"
#include "EHScopeStack.h"
#include "clang/AST/CanonicalType.h"
#include "clang/AST/Type.h"
#include "llvm/ADT/FoldingSet.h"
#include "llvm/IR/Value.h"
// FIXME: Restructure so we don't have to expose so much stuff.
#include "ABIInfo.h"
namespace llvm {
class AttributeSet;
class Function;
class Type;
class Value;
}
namespace clang {
class ASTContext;
class Decl;
class FunctionDecl;
class ObjCMethodDecl;
class VarDecl;
namespace CodeGen {
typedef SmallVector<llvm::AttributeSet, 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. Note that the argument l-value
/// is potentially null.
LValue Source;
/// The temporary alloca.
llvm::Value *Temporary;
/// A value to "use" after the writeback, or null.
llvm::Value *ToUse;
};
struct CallArgCleanup {
EHScopeStack::stable_iterator Cleanup;
/// The "is active" insertion point. This instruction is temporary and
/// will be removed after insertion.
llvm::Instruction *IsActiveIP;
};
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(LValue srcLV, llvm::Value *temporary,
llvm::Value *toUse) {
Writeback writeback;
writeback.Source = srcLV;
writeback.Temporary = temporary;
writeback.ToUse = toUse;
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(); }
void addArgCleanupDeactivation(EHScopeStack::stable_iterator Cleanup,
llvm::Instruction *IsActiveIP) {
CallArgCleanup ArgCleanup;
ArgCleanup.Cleanup = Cleanup;
ArgCleanup.IsActiveIP = IsActiveIP;
CleanupsToDeactivate.push_back(ArgCleanup);
}
ArrayRef<CallArgCleanup> getCleanupsToDeactivate() const {
return CleanupsToDeactivate;
}
private:
SmallVector<Writeback, 1> Writebacks;
/// Deactivate these cleanups immediately before making the call. This
/// is used to cleanup objects that are owned by the callee once the call
/// occurs.
SmallVector<CallArgCleanup, 1> CleanupsToDeactivate;
};
/// 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; }
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);
}
};
/// 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