llvm/lib/VMCore/Function.cpp
2011-10-17 21:33:26 +00:00

430 lines
14 KiB
C++

//===-- Function.cpp - Implement the Global object classes ----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the Function class for the VMCore library.
//
//===----------------------------------------------------------------------===//
#include "llvm/Module.h"
#include "llvm/DerivedTypes.h"
#include "llvm/IntrinsicInst.h"
#include "llvm/LLVMContext.h"
#include "llvm/CodeGen/ValueTypes.h"
#include "llvm/Support/CallSite.h"
#include "llvm/Support/InstIterator.h"
#include "llvm/Support/LeakDetector.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/StringPool.h"
#include "llvm/Support/RWMutex.h"
#include "llvm/Support/Threading.h"
#include "SymbolTableListTraitsImpl.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringExtras.h"
using namespace llvm;
// Explicit instantiations of SymbolTableListTraits since some of the methods
// are not in the public header file...
template class llvm::SymbolTableListTraits<Argument, Function>;
template class llvm::SymbolTableListTraits<BasicBlock, Function>;
//===----------------------------------------------------------------------===//
// Argument Implementation
//===----------------------------------------------------------------------===//
Argument::Argument(Type *Ty, const Twine &Name, Function *Par)
: Value(Ty, Value::ArgumentVal) {
Parent = 0;
// Make sure that we get added to a function
LeakDetector::addGarbageObject(this);
if (Par)
Par->getArgumentList().push_back(this);
setName(Name);
}
void Argument::setParent(Function *parent) {
if (getParent())
LeakDetector::addGarbageObject(this);
Parent = parent;
if (getParent())
LeakDetector::removeGarbageObject(this);
}
/// getArgNo - Return the index of this formal argument in its containing
/// function. For example in "void foo(int a, float b)" a is 0 and b is 1.
unsigned Argument::getArgNo() const {
const Function *F = getParent();
assert(F && "Argument is not in a function");
Function::const_arg_iterator AI = F->arg_begin();
unsigned ArgIdx = 0;
for (; &*AI != this; ++AI)
++ArgIdx;
return ArgIdx;
}
/// hasByValAttr - Return true if this argument has the byval attribute on it
/// in its containing function.
bool Argument::hasByValAttr() const {
if (!getType()->isPointerTy()) return false;
return getParent()->paramHasAttr(getArgNo()+1, Attribute::ByVal);
}
unsigned Argument::getParamAlignment() const {
assert(getType()->isPointerTy() && "Only pointers have alignments");
return getParent()->getParamAlignment(getArgNo()+1);
}
/// hasNestAttr - Return true if this argument has the nest attribute on
/// it in its containing function.
bool Argument::hasNestAttr() const {
if (!getType()->isPointerTy()) return false;
return getParent()->paramHasAttr(getArgNo()+1, Attribute::Nest);
}
/// hasNoAliasAttr - Return true if this argument has the noalias attribute on
/// it in its containing function.
bool Argument::hasNoAliasAttr() const {
if (!getType()->isPointerTy()) return false;
return getParent()->paramHasAttr(getArgNo()+1, Attribute::NoAlias);
}
/// hasNoCaptureAttr - Return true if this argument has the nocapture attribute
/// on it in its containing function.
bool Argument::hasNoCaptureAttr() const {
if (!getType()->isPointerTy()) return false;
return getParent()->paramHasAttr(getArgNo()+1, Attribute::NoCapture);
}
/// hasSRetAttr - Return true if this argument has the sret attribute on
/// it in its containing function.
bool Argument::hasStructRetAttr() const {
if (!getType()->isPointerTy()) return false;
if (this != getParent()->arg_begin())
return false; // StructRet param must be first param
return getParent()->paramHasAttr(1, Attribute::StructRet);
}
/// addAttr - Add a Attribute to an argument
void Argument::addAttr(Attributes attr) {
getParent()->addAttribute(getArgNo() + 1, attr);
}
/// removeAttr - Remove a Attribute from an argument
void Argument::removeAttr(Attributes attr) {
getParent()->removeAttribute(getArgNo() + 1, attr);
}
//===----------------------------------------------------------------------===//
// Helper Methods in Function
//===----------------------------------------------------------------------===//
LLVMContext &Function::getContext() const {
return getType()->getContext();
}
FunctionType *Function::getFunctionType() const {
return cast<FunctionType>(getType()->getElementType());
}
bool Function::isVarArg() const {
return getFunctionType()->isVarArg();
}
Type *Function::getReturnType() const {
return getFunctionType()->getReturnType();
}
void Function::removeFromParent() {
getParent()->getFunctionList().remove(this);
}
void Function::eraseFromParent() {
getParent()->getFunctionList().erase(this);
}
//===----------------------------------------------------------------------===//
// Function Implementation
//===----------------------------------------------------------------------===//
Function::Function(FunctionType *Ty, LinkageTypes Linkage,
const Twine &name, Module *ParentModule)
: GlobalValue(PointerType::getUnqual(Ty),
Value::FunctionVal, 0, 0, Linkage, name) {
assert(FunctionType::isValidReturnType(getReturnType()) &&
"invalid return type");
SymTab = new ValueSymbolTable();
// If the function has arguments, mark them as lazily built.
if (Ty->getNumParams())
setValueSubclassData(1); // Set the "has lazy arguments" bit.
// Make sure that we get added to a function
LeakDetector::addGarbageObject(this);
if (ParentModule)
ParentModule->getFunctionList().push_back(this);
// Ensure intrinsics have the right parameter attributes.
if (unsigned IID = getIntrinsicID())
setAttributes(Intrinsic::getAttributes(Intrinsic::ID(IID)));
}
Function::~Function() {
dropAllReferences(); // After this it is safe to delete instructions.
// Delete all of the method arguments and unlink from symbol table...
ArgumentList.clear();
delete SymTab;
// Remove the function from the on-the-side GC table.
clearGC();
}
void Function::BuildLazyArguments() const {
// Create the arguments vector, all arguments start out unnamed.
FunctionType *FT = getFunctionType();
for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i) {
assert(!FT->getParamType(i)->isVoidTy() &&
"Cannot have void typed arguments!");
ArgumentList.push_back(new Argument(FT->getParamType(i)));
}
// Clear the lazy arguments bit.
unsigned SDC = getSubclassDataFromValue();
const_cast<Function*>(this)->setValueSubclassData(SDC &= ~1);
}
size_t Function::arg_size() const {
return getFunctionType()->getNumParams();
}
bool Function::arg_empty() const {
return getFunctionType()->getNumParams() == 0;
}
void Function::setParent(Module *parent) {
if (getParent())
LeakDetector::addGarbageObject(this);
Parent = parent;
if (getParent())
LeakDetector::removeGarbageObject(this);
}
// dropAllReferences() - This function causes all the subinstructions to "let
// go" of all references that they are maintaining. This allows one to
// 'delete' a whole class at a time, even though there may be circular
// references... first all references are dropped, and all use counts go to
// zero. Then everything is deleted for real. Note that no operations are
// valid on an object that has "dropped all references", except operator
// delete.
//
void Function::dropAllReferences() {
for (iterator I = begin(), E = end(); I != E; ++I)
I->dropAllReferences();
// Delete all basic blocks. They are now unused, except possibly by
// blockaddresses, but BasicBlock's destructor takes care of those.
while (!BasicBlocks.empty())
BasicBlocks.begin()->eraseFromParent();
}
void Function::addAttribute(unsigned i, Attributes attr) {
AttrListPtr PAL = getAttributes();
PAL = PAL.addAttr(i, attr);
setAttributes(PAL);
}
void Function::removeAttribute(unsigned i, Attributes attr) {
AttrListPtr PAL = getAttributes();
PAL = PAL.removeAttr(i, attr);
setAttributes(PAL);
}
// Maintain the GC name for each function in an on-the-side table. This saves
// allocating an additional word in Function for programs which do not use GC
// (i.e., most programs) at the cost of increased overhead for clients which do
// use GC.
static DenseMap<const Function*,PooledStringPtr> *GCNames;
static StringPool *GCNamePool;
static ManagedStatic<sys::SmartRWMutex<true> > GCLock;
bool Function::hasGC() const {
sys::SmartScopedReader<true> Reader(*GCLock);
return GCNames && GCNames->count(this);
}
const char *Function::getGC() const {
assert(hasGC() && "Function has no collector");
sys::SmartScopedReader<true> Reader(*GCLock);
return *(*GCNames)[this];
}
void Function::setGC(const char *Str) {
sys::SmartScopedWriter<true> Writer(*GCLock);
if (!GCNamePool)
GCNamePool = new StringPool();
if (!GCNames)
GCNames = new DenseMap<const Function*,PooledStringPtr>();
(*GCNames)[this] = GCNamePool->intern(Str);
}
void Function::clearGC() {
sys::SmartScopedWriter<true> Writer(*GCLock);
if (GCNames) {
GCNames->erase(this);
if (GCNames->empty()) {
delete GCNames;
GCNames = 0;
if (GCNamePool->empty()) {
delete GCNamePool;
GCNamePool = 0;
}
}
}
}
/// copyAttributesFrom - copy all additional attributes (those not needed to
/// create a Function) from the Function Src to this one.
void Function::copyAttributesFrom(const GlobalValue *Src) {
assert(isa<Function>(Src) && "Expected a Function!");
GlobalValue::copyAttributesFrom(Src);
const Function *SrcF = cast<Function>(Src);
setCallingConv(SrcF->getCallingConv());
setAttributes(SrcF->getAttributes());
if (SrcF->hasGC())
setGC(SrcF->getGC());
else
clearGC();
}
/// getIntrinsicID - This method returns the ID number of the specified
/// function, or Intrinsic::not_intrinsic if the function is not an
/// intrinsic, or if the pointer is null. This value is always defined to be
/// zero to allow easy checking for whether a function is intrinsic or not. The
/// particular intrinsic functions which correspond to this value are defined in
/// llvm/Intrinsics.h.
///
unsigned Function::getIntrinsicID() const {
const ValueName *ValName = this->getValueName();
if (!ValName)
return 0;
unsigned Len = ValName->getKeyLength();
const char *Name = ValName->getKeyData();
if (Len < 5 || Name[4] != '.' || Name[0] != 'l' || Name[1] != 'l'
|| Name[2] != 'v' || Name[3] != 'm')
return 0; // All intrinsics start with 'llvm.'
#define GET_FUNCTION_RECOGNIZER
#include "llvm/Intrinsics.gen"
#undef GET_FUNCTION_RECOGNIZER
return 0;
}
std::string Intrinsic::getName(ID id, ArrayRef<Type*> Tys) {
assert(id < num_intrinsics && "Invalid intrinsic ID!");
static const char * const Table[] = {
"not_intrinsic",
#define GET_INTRINSIC_NAME_TABLE
#include "llvm/Intrinsics.gen"
#undef GET_INTRINSIC_NAME_TABLE
};
if (Tys.empty())
return Table[id];
std::string Result(Table[id]);
for (unsigned i = 0; i < Tys.size(); ++i) {
if (PointerType* PTyp = dyn_cast<PointerType>(Tys[i])) {
Result += ".p" + llvm::utostr(PTyp->getAddressSpace()) +
EVT::getEVT(PTyp->getElementType()).getEVTString();
}
else if (Tys[i])
Result += "." + EVT::getEVT(Tys[i]).getEVTString();
}
return Result;
}
FunctionType *Intrinsic::getType(LLVMContext &Context,
ID id, ArrayRef<Type*> Tys) {
Type *ResultTy = NULL;
SmallVector<Type*, 8> ArgTys;
bool IsVarArg = false;
#define GET_INTRINSIC_GENERATOR
#include "llvm/Intrinsics.gen"
#undef GET_INTRINSIC_GENERATOR
return FunctionType::get(ResultTy, ArgTys, IsVarArg);
}
bool Intrinsic::isOverloaded(ID id) {
static const bool OTable[] = {
false,
#define GET_INTRINSIC_OVERLOAD_TABLE
#include "llvm/Intrinsics.gen"
#undef GET_INTRINSIC_OVERLOAD_TABLE
};
return OTable[id];
}
/// This defines the "Intrinsic::getAttributes(ID id)" method.
#define GET_INTRINSIC_ATTRIBUTES
#include "llvm/Intrinsics.gen"
#undef GET_INTRINSIC_ATTRIBUTES
Function *Intrinsic::getDeclaration(Module *M, ID id, ArrayRef<Type*> Tys) {
// There can never be multiple globals with the same name of different types,
// because intrinsics must be a specific type.
return
cast<Function>(M->getOrInsertFunction(getName(id, Tys),
getType(M->getContext(), id, Tys)));
}
// This defines the "Intrinsic::getIntrinsicForGCCBuiltin()" method.
#define GET_LLVM_INTRINSIC_FOR_GCC_BUILTIN
#include "llvm/Intrinsics.gen"
#undef GET_LLVM_INTRINSIC_FOR_GCC_BUILTIN
/// hasAddressTaken - returns true if there are any uses of this function
/// other than direct calls or invokes to it.
bool Function::hasAddressTaken(const User* *PutOffender) const {
for (Value::const_use_iterator I = use_begin(), E = use_end(); I != E; ++I) {
const User *U = *I;
if (!isa<CallInst>(U) && !isa<InvokeInst>(U))
return PutOffender ? (*PutOffender = U, true) : true;
ImmutableCallSite CS(cast<Instruction>(U));
if (!CS.isCallee(I))
return PutOffender ? (*PutOffender = U, true) : true;
}
return false;
}
/// callsFunctionThatReturnsTwice - Return true if the function has a call to
/// setjmp or other function that gcc recognizes as "returning twice".
bool Function::callsFunctionThatReturnsTwice() const {
for (const_inst_iterator
I = inst_begin(this), E = inst_end(this); I != E; ++I) {
const CallInst* callInst = dyn_cast<CallInst>(&*I);
if (!callInst)
continue;
if (callInst->canReturnTwice())
return true;
}
return false;
}
// vim: sw=2 ai