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llvm-6502/lib/ExecutionEngine/JIT/JITDwarfEmitter.cpp
Dan Gohman 844731a7f1 Clean up the use of static and anonymous namespaces. This turned up 
several things that were neither in an anonymous namespace nor static
but not intended to be global.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51017 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-13 00:00:25 +00:00

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//===----- JITDwarfEmitter.cpp - Write dwarf tables into memory -----------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines a JITDwarfEmitter object that is used by the JIT to
// write dwarf tables to memory.
//
//===----------------------------------------------------------------------===//
#include "JIT.h"
#include "JITDwarfEmitter.h"
#include "llvm/Function.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/CodeGen/MachineCodeEmitter.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineLocation.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/ExecutionEngine/JITMemoryManager.h"
#include "llvm/Target/TargetAsmInfo.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetFrameInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetRegisterInfo.h"
using namespace llvm;
JITDwarfEmitter::JITDwarfEmitter(JIT& theJit) : Jit(theJit) {}
unsigned char* JITDwarfEmitter::EmitDwarfTable(MachineFunction& F,
MachineCodeEmitter& mce,
unsigned char* StartFunction,
unsigned char* EndFunction) {
const TargetMachine& TM = F.getTarget();
TD = TM.getTargetData();
needsIndirectEncoding = TM.getTargetAsmInfo()->getNeedsIndirectEncoding();
stackGrowthDirection = TM.getFrameInfo()->getStackGrowthDirection();
RI = TM.getRegisterInfo();
MCE = &mce;
unsigned char* ExceptionTable = EmitExceptionTable(&F, StartFunction,
EndFunction);
unsigned char* Result = 0;
unsigned char* EHFramePtr = 0;
const std::vector<Function *> Personalities = MMI->getPersonalities();
EHFramePtr = EmitCommonEHFrame(Personalities[MMI->getPersonalityIndex()]);
Result = EmitEHFrame(Personalities[MMI->getPersonalityIndex()], EHFramePtr,
StartFunction, EndFunction, ExceptionTable);
return Result;
}
void
JITDwarfEmitter::EmitFrameMoves(intptr_t BaseLabelPtr,
const std::vector<MachineMove> &Moves) const {
unsigned PointerSize = TD->getPointerSize();
int stackGrowth = stackGrowthDirection == TargetFrameInfo::StackGrowsUp ?
PointerSize : -PointerSize;
bool IsLocal = BaseLabelPtr;
for (unsigned i = 0, N = Moves.size(); i < N; ++i) {
const MachineMove &Move = Moves[i];
unsigned LabelID = Move.getLabelID();
if (LabelID) {
LabelID = MMI->MappedLabel(LabelID);
// Throw out move if the label is invalid.
if (!LabelID) continue;
}
intptr_t LabelPtr = 0;
if (LabelID) LabelPtr = MCE->getLabelAddress(LabelID);
const MachineLocation &Dst = Move.getDestination();
const MachineLocation &Src = Move.getSource();
// Advance row if new location.
if (BaseLabelPtr && LabelID && (BaseLabelPtr != LabelPtr || !IsLocal)) {
MCE->emitByte(dwarf::DW_CFA_advance_loc4);
if (PointerSize == 8) {
MCE->emitInt64(LabelPtr - BaseLabelPtr);
} else {
MCE->emitInt32(LabelPtr - BaseLabelPtr);
}
BaseLabelPtr = LabelPtr;
IsLocal = true;
}
// If advancing cfa.
if (Dst.isRegister() && Dst.getRegister() == MachineLocation::VirtualFP) {
if (!Src.isRegister()) {
if (Src.getRegister() == MachineLocation::VirtualFP) {
MCE->emitByte(dwarf::DW_CFA_def_cfa_offset);
} else {
MCE->emitByte(dwarf::DW_CFA_def_cfa);
MCE->emitULEB128Bytes(RI->getDwarfRegNum(Src.getRegister(), true));
}
int Offset = -Src.getOffset();
MCE->emitULEB128Bytes(Offset);
} else {
assert(0 && "Machine move no supported yet.");
}
} else if (Src.isRegister() &&
Src.getRegister() == MachineLocation::VirtualFP) {
if (Dst.isRegister()) {
MCE->emitByte(dwarf::DW_CFA_def_cfa_register);
MCE->emitULEB128Bytes(RI->getDwarfRegNum(Dst.getRegister(), true));
} else {
assert(0 && "Machine move no supported yet.");
}
} else {
unsigned Reg = RI->getDwarfRegNum(Src.getRegister(), true);
int Offset = Dst.getOffset() / stackGrowth;
if (Offset < 0) {
MCE->emitByte(dwarf::DW_CFA_offset_extended_sf);
MCE->emitULEB128Bytes(Reg);
MCE->emitSLEB128Bytes(Offset);
} else if (Reg < 64) {
MCE->emitByte(dwarf::DW_CFA_offset + Reg);
MCE->emitULEB128Bytes(Offset);
} else {
MCE->emitByte(dwarf::DW_CFA_offset_extended);
MCE->emitULEB128Bytes(Reg);
MCE->emitULEB128Bytes(Offset);
}
}
}
}
/// SharedTypeIds - How many leading type ids two landing pads have in common.
static unsigned SharedTypeIds(const LandingPadInfo *L,
const LandingPadInfo *R) {
const std::vector<int> &LIds = L->TypeIds, &RIds = R->TypeIds;
unsigned LSize = LIds.size(), RSize = RIds.size();
unsigned MinSize = LSize < RSize ? LSize : RSize;
unsigned Count = 0;
for (; Count != MinSize; ++Count)
if (LIds[Count] != RIds[Count])
return Count;
return Count;
}
/// PadLT - Order landing pads lexicographically by type id.
static bool PadLT(const LandingPadInfo *L, const LandingPadInfo *R) {
const std::vector<int> &LIds = L->TypeIds, &RIds = R->TypeIds;
unsigned LSize = LIds.size(), RSize = RIds.size();
unsigned MinSize = LSize < RSize ? LSize : RSize;
for (unsigned i = 0; i != MinSize; ++i)
if (LIds[i] != RIds[i])
return LIds[i] < RIds[i];
return LSize < RSize;
}
namespace {
struct KeyInfo {
static inline unsigned getEmptyKey() { return -1U; }
static inline unsigned getTombstoneKey() { return -2U; }
static unsigned getHashValue(const unsigned &Key) { return Key; }
static bool isEqual(unsigned LHS, unsigned RHS) { return LHS == RHS; }
static bool isPod() { return true; }
};
/// ActionEntry - Structure describing an entry in the actions table.
struct ActionEntry {
int ValueForTypeID; // The value to write - may not be equal to the type id.
int NextAction;
struct ActionEntry *Previous;
};
/// PadRange - Structure holding a try-range and the associated landing pad.
struct PadRange {
// The index of the landing pad.
unsigned PadIndex;
// The index of the begin and end labels in the landing pad's label lists.
unsigned RangeIndex;
};
typedef DenseMap<unsigned, PadRange, KeyInfo> RangeMapType;
/// CallSiteEntry - Structure describing an entry in the call-site table.
struct CallSiteEntry {
unsigned BeginLabel; // zero indicates the start of the function.
unsigned EndLabel; // zero indicates the end of the function.
unsigned PadLabel; // zero indicates that there is no landing pad.
unsigned Action;
};
}
unsigned char* JITDwarfEmitter::EmitExceptionTable(MachineFunction* MF,
unsigned char* StartFunction,
unsigned char* EndFunction) const {
// Map all labels and get rid of any dead landing pads.
MMI->TidyLandingPads();
const std::vector<GlobalVariable *> &TypeInfos = MMI->getTypeInfos();
const std::vector<unsigned> &FilterIds = MMI->getFilterIds();
const std::vector<LandingPadInfo> &PadInfos = MMI->getLandingPads();
if (PadInfos.empty()) return 0;
// Sort the landing pads in order of their type ids. This is used to fold
// duplicate actions.
SmallVector<const LandingPadInfo *, 64> LandingPads;
LandingPads.reserve(PadInfos.size());
for (unsigned i = 0, N = PadInfos.size(); i != N; ++i)
LandingPads.push_back(&PadInfos[i]);
std::sort(LandingPads.begin(), LandingPads.end(), PadLT);
// Negative type ids index into FilterIds, positive type ids index into
// TypeInfos. The value written for a positive type id is just the type
// id itself. For a negative type id, however, the value written is the
// (negative) byte offset of the corresponding FilterIds entry. The byte
// offset is usually equal to the type id, because the FilterIds entries
// are written using a variable width encoding which outputs one byte per
// entry as long as the value written is not too large, but can differ.
// This kind of complication does not occur for positive type ids because
// type infos are output using a fixed width encoding.
// FilterOffsets[i] holds the byte offset corresponding to FilterIds[i].
SmallVector<int, 16> FilterOffsets;
FilterOffsets.reserve(FilterIds.size());
int Offset = -1;
for(std::vector<unsigned>::const_iterator I = FilterIds.begin(),
E = FilterIds.end(); I != E; ++I) {
FilterOffsets.push_back(Offset);
Offset -= AsmPrinter::SizeULEB128(*I);
}
// Compute the actions table and gather the first action index for each
// landing pad site.
SmallVector<ActionEntry, 32> Actions;
SmallVector<unsigned, 64> FirstActions;
FirstActions.reserve(LandingPads.size());
int FirstAction = 0;
unsigned SizeActions = 0;
for (unsigned i = 0, N = LandingPads.size(); i != N; ++i) {
const LandingPadInfo *LP = LandingPads[i];
const std::vector<int> &TypeIds = LP->TypeIds;
const unsigned NumShared = i ? SharedTypeIds(LP, LandingPads[i-1]) : 0;
unsigned SizeSiteActions = 0;
if (NumShared < TypeIds.size()) {
unsigned SizeAction = 0;
ActionEntry *PrevAction = 0;
if (NumShared) {
const unsigned SizePrevIds = LandingPads[i-1]->TypeIds.size();
assert(Actions.size());
PrevAction = &Actions.back();
SizeAction = AsmPrinter::SizeSLEB128(PrevAction->NextAction) +
AsmPrinter::SizeSLEB128(PrevAction->ValueForTypeID);
for (unsigned j = NumShared; j != SizePrevIds; ++j) {
SizeAction -= AsmPrinter::SizeSLEB128(PrevAction->ValueForTypeID);
SizeAction += -PrevAction->NextAction;
PrevAction = PrevAction->Previous;
}
}
// Compute the actions.
for (unsigned I = NumShared, M = TypeIds.size(); I != M; ++I) {
int TypeID = TypeIds[I];
assert(-1-TypeID < (int)FilterOffsets.size() && "Unknown filter id!");
int ValueForTypeID = TypeID < 0 ? FilterOffsets[-1 - TypeID] : TypeID;
unsigned SizeTypeID = AsmPrinter::SizeSLEB128(ValueForTypeID);
int NextAction = SizeAction ? -(SizeAction + SizeTypeID) : 0;
SizeAction = SizeTypeID + AsmPrinter::SizeSLEB128(NextAction);
SizeSiteActions += SizeAction;
ActionEntry Action = {ValueForTypeID, NextAction, PrevAction};
Actions.push_back(Action);
PrevAction = &Actions.back();
}
// Record the first action of the landing pad site.
FirstAction = SizeActions + SizeSiteActions - SizeAction + 1;
} // else identical - re-use previous FirstAction
FirstActions.push_back(FirstAction);
// Compute this sites contribution to size.
SizeActions += SizeSiteActions;
}
// Compute the call-site table. Entries must be ordered by address.
SmallVector<CallSiteEntry, 64> CallSites;
RangeMapType PadMap;
for (unsigned i = 0, N = LandingPads.size(); i != N; ++i) {
const LandingPadInfo *LandingPad = LandingPads[i];
for (unsigned j=0, E = LandingPad->BeginLabels.size(); j != E; ++j) {
unsigned BeginLabel = LandingPad->BeginLabels[j];
assert(!PadMap.count(BeginLabel) && "Duplicate landing pad labels!");
PadRange P = { i, j };
PadMap[BeginLabel] = P;
}
}
bool MayThrow = false;
unsigned LastLabel = 0;
for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
I != E; ++I) {
for (MachineBasicBlock::const_iterator MI = I->begin(), E = I->end();
MI != E; ++MI) {
if (MI->getOpcode() != TargetInstrInfo::LABEL) {
MayThrow |= MI->getDesc().isCall();
continue;
}
unsigned BeginLabel = MI->getOperand(0).getImm();
assert(BeginLabel && "Invalid label!");
if (BeginLabel == LastLabel)
MayThrow = false;
RangeMapType::iterator L = PadMap.find(BeginLabel);
if (L == PadMap.end())
continue;
PadRange P = L->second;
const LandingPadInfo *LandingPad = LandingPads[P.PadIndex];
assert(BeginLabel == LandingPad->BeginLabels[P.RangeIndex] &&
"Inconsistent landing pad map!");
// If some instruction between the previous try-range and this one may
// throw, create a call-site entry with no landing pad for the region
// between the try-ranges.
if (MayThrow) {
CallSiteEntry Site = {LastLabel, BeginLabel, 0, 0};
CallSites.push_back(Site);
}
LastLabel = LandingPad->EndLabels[P.RangeIndex];
CallSiteEntry Site = {BeginLabel, LastLabel,
LandingPad->LandingPadLabel, FirstActions[P.PadIndex]};
assert(Site.BeginLabel && Site.EndLabel && Site.PadLabel &&
"Invalid landing pad!");
// Try to merge with the previous call-site.
if (CallSites.size()) {
CallSiteEntry &Prev = CallSites[CallSites.size()-1];
if (Site.PadLabel == Prev.PadLabel && Site.Action == Prev.Action) {
// Extend the range of the previous entry.
Prev.EndLabel = Site.EndLabel;
continue;
}
}
// Otherwise, create a new call-site.
CallSites.push_back(Site);
}
}
// If some instruction between the previous try-range and the end of the
// function may throw, create a call-site entry with no landing pad for the
// region following the try-range.
if (MayThrow) {
CallSiteEntry Site = {LastLabel, 0, 0, 0};
CallSites.push_back(Site);
}
// Final tallies.
unsigned SizeSites = CallSites.size() * (sizeof(int32_t) + // Site start.
sizeof(int32_t) + // Site length.
sizeof(int32_t)); // Landing pad.
for (unsigned i = 0, e = CallSites.size(); i < e; ++i)
SizeSites += AsmPrinter::SizeULEB128(CallSites[i].Action);
unsigned SizeTypes = TypeInfos.size() * TD->getPointerSize();
unsigned TypeOffset = sizeof(int8_t) + // Call site format
// Call-site table length
AsmPrinter::SizeULEB128(SizeSites) +
SizeSites + SizeActions + SizeTypes;
unsigned TotalSize = sizeof(int8_t) + // LPStart format
sizeof(int8_t) + // TType format
AsmPrinter::SizeULEB128(TypeOffset) + // TType base offset
TypeOffset;
unsigned SizeAlign = (4 - TotalSize) & 3;
// Begin the exception table.
MCE->emitAlignment(4);
for (unsigned i = 0; i != SizeAlign; ++i) {
MCE->emitByte(0);
// Asm->EOL("Padding");
}
unsigned char* DwarfExceptionTable = (unsigned char*)MCE->getCurrentPCValue();
// Emit the header.
MCE->emitByte(dwarf::DW_EH_PE_omit);
// Asm->EOL("LPStart format (DW_EH_PE_omit)");
MCE->emitByte(dwarf::DW_EH_PE_absptr);
// Asm->EOL("TType format (DW_EH_PE_absptr)");
MCE->emitULEB128Bytes(TypeOffset);
// Asm->EOL("TType base offset");
MCE->emitByte(dwarf::DW_EH_PE_udata4);
// Asm->EOL("Call site format (DW_EH_PE_udata4)");
MCE->emitULEB128Bytes(SizeSites);
// Asm->EOL("Call-site table length");
// Emit the landing pad site information.
for (unsigned i = 0; i < CallSites.size(); ++i) {
CallSiteEntry &S = CallSites[i];
intptr_t BeginLabelPtr = 0;
intptr_t EndLabelPtr = 0;
if (!S.BeginLabel) {
BeginLabelPtr = (intptr_t)StartFunction;
if (TD->getPointerSize() == sizeof(int32_t))
MCE->emitInt32(0);
else
MCE->emitInt64(0);
} else {
BeginLabelPtr = MCE->getLabelAddress(S.BeginLabel);
if (TD->getPointerSize() == sizeof(int32_t))
MCE->emitInt32(BeginLabelPtr - (intptr_t)StartFunction);
else
MCE->emitInt64(BeginLabelPtr - (intptr_t)StartFunction);
}
// Asm->EOL("Region start");
if (!S.EndLabel) {
EndLabelPtr = (intptr_t)EndFunction;
if (TD->getPointerSize() == sizeof(int32_t))
MCE->emitInt32((intptr_t)EndFunction - BeginLabelPtr);
else
MCE->emitInt64((intptr_t)EndFunction - BeginLabelPtr);
} else {
EndLabelPtr = MCE->getLabelAddress(S.EndLabel);
if (TD->getPointerSize() == sizeof(int32_t))
MCE->emitInt32(EndLabelPtr - BeginLabelPtr);
else
MCE->emitInt64(EndLabelPtr - BeginLabelPtr);
}
//Asm->EOL("Region length");
if (!S.PadLabel) {
if (TD->getPointerSize() == sizeof(int32_t))
MCE->emitInt32(0);
else
MCE->emitInt64(0);
} else {
unsigned PadLabelPtr = MCE->getLabelAddress(S.PadLabel);
if (TD->getPointerSize() == sizeof(int32_t))
MCE->emitInt32(PadLabelPtr - (intptr_t)StartFunction);
else
MCE->emitInt64(PadLabelPtr - (intptr_t)StartFunction);
}
// Asm->EOL("Landing pad");
MCE->emitULEB128Bytes(S.Action);
// Asm->EOL("Action");
}
// Emit the actions.
for (unsigned I = 0, N = Actions.size(); I != N; ++I) {
ActionEntry &Action = Actions[I];
MCE->emitSLEB128Bytes(Action.ValueForTypeID);
//Asm->EOL("TypeInfo index");
MCE->emitSLEB128Bytes(Action.NextAction);
//Asm->EOL("Next action");
}
// Emit the type ids.
for (unsigned M = TypeInfos.size(); M; --M) {
GlobalVariable *GV = TypeInfos[M - 1];
if (GV) {
if (TD->getPointerSize() == sizeof(int32_t)) {
MCE->emitInt32((intptr_t)Jit.getOrEmitGlobalVariable(GV));
} else {
MCE->emitInt64((intptr_t)Jit.getOrEmitGlobalVariable(GV));
}
} else {
if (TD->getPointerSize() == sizeof(int32_t))
MCE->emitInt32(0);
else
MCE->emitInt64(0);
}
// Asm->EOL("TypeInfo");
}
// Emit the filter typeids.
for (unsigned j = 0, M = FilterIds.size(); j < M; ++j) {
unsigned TypeID = FilterIds[j];
MCE->emitULEB128Bytes(TypeID);
//Asm->EOL("Filter TypeInfo index");
}
MCE->emitAlignment(4);
return DwarfExceptionTable;
}
unsigned char*
JITDwarfEmitter::EmitCommonEHFrame(const Function* Personality) const {
unsigned PointerSize = TD->getPointerSize();
int stackGrowth = stackGrowthDirection == TargetFrameInfo::StackGrowsUp ?
PointerSize : -PointerSize;
unsigned char* StartCommonPtr = (unsigned char*)MCE->getCurrentPCValue();
// EH Common Frame header
MCE->allocateSpace(PointerSize, 0);
unsigned char* FrameCommonBeginPtr = (unsigned char*)MCE->getCurrentPCValue();
MCE->emitInt32((int)0);
MCE->emitByte(dwarf::DW_CIE_VERSION);
MCE->emitString(Personality ? "zPLR" : "zR");
MCE->emitULEB128Bytes(1);
MCE->emitSLEB128Bytes(stackGrowth);
MCE->emitByte(RI->getDwarfRegNum(RI->getRARegister(), true));
if (Personality) {
MCE->emitULEB128Bytes(7);
if (needsIndirectEncoding)
MCE->emitByte(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4 |
dwarf::DW_EH_PE_indirect);
else
MCE->emitByte(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4);
if (PointerSize == 8)
MCE->emitInt64((intptr_t)Jit.getPointerToGlobal(Personality) -
MCE->getCurrentPCValue());
else
MCE->emitInt32((intptr_t)Jit.getPointerToGlobal(Personality) -
MCE->getCurrentPCValue());
MCE->emitULEB128Bytes(dwarf::DW_EH_PE_pcrel);
MCE->emitULEB128Bytes(dwarf::DW_EH_PE_pcrel);
} else {
MCE->emitULEB128Bytes(1);
MCE->emitULEB128Bytes(dwarf::DW_EH_PE_pcrel);
}
std::vector<MachineMove> Moves;
RI->getInitialFrameState(Moves);
EmitFrameMoves(0, Moves);
MCE->emitAlignment(4);
MCE->emitAt((uintptr_t*)StartCommonPtr,
(uintptr_t)((unsigned char*)MCE->getCurrentPCValue() -
FrameCommonBeginPtr));
return StartCommonPtr;
}
unsigned char*
JITDwarfEmitter::EmitEHFrame(const Function* Personality,
unsigned char* StartCommonPtr,
unsigned char* StartFunction,
unsigned char* EndFunction,
unsigned char* ExceptionTable) const {
unsigned PointerSize = TD->getPointerSize();
// EH frame header.
unsigned char* StartEHPtr = (unsigned char*)MCE->getCurrentPCValue();
MCE->allocateSpace(PointerSize, 0);
unsigned char* FrameBeginPtr = (unsigned char*)MCE->getCurrentPCValue();
// FDE CIE Offset
if (PointerSize == 8) {
MCE->emitInt64(FrameBeginPtr - StartCommonPtr);
MCE->emitInt64(StartFunction - (unsigned char*)MCE->getCurrentPCValue());
MCE->emitInt64(EndFunction - StartFunction);
} else {
MCE->emitInt32(FrameBeginPtr - StartCommonPtr);
MCE->emitInt32(StartFunction - (unsigned char*)MCE->getCurrentPCValue());
MCE->emitInt32(EndFunction - StartFunction);
}
// If there is a personality and landing pads then point to the language
// specific data area in the exception table.
if (MMI->getPersonalityIndex()) {
MCE->emitULEB128Bytes(4);
if (!MMI->getLandingPads().empty()) {
if (PointerSize == 8)
MCE->emitInt64(ExceptionTable - (unsigned char*)MCE->getCurrentPCValue());
else
MCE->emitInt32(ExceptionTable - (unsigned char*)MCE->getCurrentPCValue());
} else if (PointerSize == 8) {
MCE->emitInt64((int)0);
} else {
MCE->emitInt32((int)0);
}
} else {
MCE->emitULEB128Bytes(0);
}
// Indicate locations of function specific callee saved registers in
// frame.
EmitFrameMoves((intptr_t)StartFunction, MMI->getFrameMoves());
MCE->emitAlignment(4);
// Indicate the size of the table
MCE->emitAt((uintptr_t*)StartEHPtr,
(uintptr_t)((unsigned char*)MCE->getCurrentPCValue() -
StartEHPtr));
// Double zeroes for the unwind runtime
if (PointerSize == 8) {
MCE->emitInt64(0);
MCE->emitInt64(0);
} else {
MCE->emitInt32(0);
MCE->emitInt32(0);
}
return StartEHPtr;
}
unsigned JITDwarfEmitter::GetDwarfTableSizeInBytes(MachineFunction& F,
MachineCodeEmitter& mce,
unsigned char* StartFunction,
unsigned char* EndFunction) {
const TargetMachine& TM = F.getTarget();
TD = TM.getTargetData();
needsIndirectEncoding = TM.getTargetAsmInfo()->getNeedsIndirectEncoding();
stackGrowthDirection = TM.getFrameInfo()->getStackGrowthDirection();
RI = TM.getRegisterInfo();
MCE = &mce;
unsigned FinalSize = 0;
FinalSize += GetExceptionTableSizeInBytes(&F);
const std::vector<Function *> Personalities = MMI->getPersonalities();
FinalSize += GetCommonEHFrameSizeInBytes(Personalities[MMI->getPersonalityIndex()]);
FinalSize += GetEHFrameSizeInBytes(Personalities[MMI->getPersonalityIndex()], StartFunction);
return FinalSize;
}
/// RoundUpToAlign - Add the specified alignment to FinalSize and returns
/// the new value.
static unsigned RoundUpToAlign(unsigned FinalSize, unsigned Alignment) {
if (Alignment == 0) Alignment = 1;
// Since we do not know where the buffer will be allocated, be pessimistic.
return FinalSize + Alignment;
}
unsigned
JITDwarfEmitter::GetEHFrameSizeInBytes(const Function* Personality,
unsigned char* StartFunction) const {
unsigned PointerSize = TD->getPointerSize();
unsigned FinalSize = 0;
// EH frame header.
FinalSize += PointerSize;
// FDE CIE Offset
FinalSize += 3 * PointerSize;
// If there is a personality and landing pads then point to the language
// specific data area in the exception table.
if (MMI->getPersonalityIndex()) {
FinalSize += AsmPrinter::SizeULEB128(4);
FinalSize += PointerSize;
} else {
FinalSize += AsmPrinter::SizeULEB128(0);
}
// Indicate locations of function specific callee saved registers in
// frame.
FinalSize += GetFrameMovesSizeInBytes((intptr_t)StartFunction,
MMI->getFrameMoves());
FinalSize = RoundUpToAlign(FinalSize, 4);
// Double zeroes for the unwind runtime
FinalSize += 2 * PointerSize;
return FinalSize;
}
unsigned JITDwarfEmitter::GetCommonEHFrameSizeInBytes(const Function* Personality)
const {
unsigned PointerSize = TD->getPointerSize();
int stackGrowth = stackGrowthDirection == TargetFrameInfo::StackGrowsUp ?
PointerSize : -PointerSize;
unsigned FinalSize = 0;
// EH Common Frame header
FinalSize += PointerSize;
FinalSize += 4;
FinalSize += 1;
FinalSize += Personality ? 5 : 3; // "zPLR" or "zR"
FinalSize += AsmPrinter::SizeULEB128(1);
FinalSize += AsmPrinter::SizeSLEB128(stackGrowth);
FinalSize += 1;
if (Personality) {
FinalSize += AsmPrinter::SizeULEB128(7);
// Encoding
FinalSize+= 1;
//Personality
FinalSize += PointerSize;
FinalSize += AsmPrinter::SizeULEB128(dwarf::DW_EH_PE_pcrel);
FinalSize += AsmPrinter::SizeULEB128(dwarf::DW_EH_PE_pcrel);
} else {
FinalSize += AsmPrinter::SizeULEB128(1);
FinalSize += AsmPrinter::SizeULEB128(dwarf::DW_EH_PE_pcrel);
}
std::vector<MachineMove> Moves;
RI->getInitialFrameState(Moves);
FinalSize += GetFrameMovesSizeInBytes(0, Moves);
FinalSize = RoundUpToAlign(FinalSize, 4);
return FinalSize;
}
unsigned
JITDwarfEmitter::GetFrameMovesSizeInBytes(intptr_t BaseLabelPtr,
const std::vector<MachineMove> &Moves) const {
unsigned PointerSize = TD->getPointerSize();
int stackGrowth = stackGrowthDirection == TargetFrameInfo::StackGrowsUp ?
PointerSize : -PointerSize;
bool IsLocal = BaseLabelPtr;
unsigned FinalSize = 0;
for (unsigned i = 0, N = Moves.size(); i < N; ++i) {
const MachineMove &Move = Moves[i];
unsigned LabelID = Move.getLabelID();
if (LabelID) {
LabelID = MMI->MappedLabel(LabelID);
// Throw out move if the label is invalid.
if (!LabelID) continue;
}
intptr_t LabelPtr = 0;
if (LabelID) LabelPtr = MCE->getLabelAddress(LabelID);
const MachineLocation &Dst = Move.getDestination();
const MachineLocation &Src = Move.getSource();
// Advance row if new location.
if (BaseLabelPtr && LabelID && (BaseLabelPtr != LabelPtr || !IsLocal)) {
FinalSize++;
FinalSize += PointerSize;
BaseLabelPtr = LabelPtr;
IsLocal = true;
}
// If advancing cfa.
if (Dst.isRegister() && Dst.getRegister() == MachineLocation::VirtualFP) {
if (!Src.isRegister()) {
if (Src.getRegister() == MachineLocation::VirtualFP) {
++FinalSize;
} else {
++FinalSize;
unsigned RegNum = RI->getDwarfRegNum(Src.getRegister(), true);
FinalSize += AsmPrinter::SizeULEB128(RegNum);
}
int Offset = -Src.getOffset();
FinalSize += AsmPrinter::SizeULEB128(Offset);
} else {
assert(0 && "Machine move no supported yet.");
}
} else if (Src.isRegister() &&
Src.getRegister() == MachineLocation::VirtualFP) {
if (Dst.isRegister()) {
++FinalSize;
unsigned RegNum = RI->getDwarfRegNum(Dst.getRegister(), true);
FinalSize += AsmPrinter::SizeULEB128(RegNum);
} else {
assert(0 && "Machine move no supported yet.");
}
} else {
unsigned Reg = RI->getDwarfRegNum(Src.getRegister(), true);
int Offset = Dst.getOffset() / stackGrowth;
if (Offset < 0) {
++FinalSize;
FinalSize += AsmPrinter::SizeULEB128(Reg);
FinalSize += AsmPrinter::SizeSLEB128(Offset);
} else if (Reg < 64) {
++FinalSize;
FinalSize += AsmPrinter::SizeULEB128(Offset);
} else {
++FinalSize;
FinalSize += AsmPrinter::SizeULEB128(Reg);
FinalSize += AsmPrinter::SizeULEB128(Offset);
}
}
}
return FinalSize;
}
unsigned
JITDwarfEmitter::GetExceptionTableSizeInBytes(MachineFunction* MF) const {
unsigned FinalSize = 0;
// Map all labels and get rid of any dead landing pads.
MMI->TidyLandingPads();
const std::vector<GlobalVariable *> &TypeInfos = MMI->getTypeInfos();
const std::vector<unsigned> &FilterIds = MMI->getFilterIds();
const std::vector<LandingPadInfo> &PadInfos = MMI->getLandingPads();
if (PadInfos.empty()) return 0;
// Sort the landing pads in order of their type ids. This is used to fold
// duplicate actions.
SmallVector<const LandingPadInfo *, 64> LandingPads;
LandingPads.reserve(PadInfos.size());
for (unsigned i = 0, N = PadInfos.size(); i != N; ++i)
LandingPads.push_back(&PadInfos[i]);
std::sort(LandingPads.begin(), LandingPads.end(), PadLT);
// Negative type ids index into FilterIds, positive type ids index into
// TypeInfos. The value written for a positive type id is just the type
// id itself. For a negative type id, however, the value written is the
// (negative) byte offset of the corresponding FilterIds entry. The byte
// offset is usually equal to the type id, because the FilterIds entries
// are written using a variable width encoding which outputs one byte per
// entry as long as the value written is not too large, but can differ.
// This kind of complication does not occur for positive type ids because
// type infos are output using a fixed width encoding.
// FilterOffsets[i] holds the byte offset corresponding to FilterIds[i].
SmallVector<int, 16> FilterOffsets;
FilterOffsets.reserve(FilterIds.size());
int Offset = -1;
for(std::vector<unsigned>::const_iterator I = FilterIds.begin(),
E = FilterIds.end(); I != E; ++I) {
FilterOffsets.push_back(Offset);
Offset -= AsmPrinter::SizeULEB128(*I);
}
// Compute the actions table and gather the first action index for each
// landing pad site.
SmallVector<ActionEntry, 32> Actions;
SmallVector<unsigned, 64> FirstActions;
FirstActions.reserve(LandingPads.size());
int FirstAction = 0;
unsigned SizeActions = 0;
for (unsigned i = 0, N = LandingPads.size(); i != N; ++i) {
const LandingPadInfo *LP = LandingPads[i];
const std::vector<int> &TypeIds = LP->TypeIds;
const unsigned NumShared = i ? SharedTypeIds(LP, LandingPads[i-1]) : 0;
unsigned SizeSiteActions = 0;
if (NumShared < TypeIds.size()) {
unsigned SizeAction = 0;
ActionEntry *PrevAction = 0;
if (NumShared) {
const unsigned SizePrevIds = LandingPads[i-1]->TypeIds.size();
assert(Actions.size());
PrevAction = &Actions.back();
SizeAction = AsmPrinter::SizeSLEB128(PrevAction->NextAction) +
AsmPrinter::SizeSLEB128(PrevAction->ValueForTypeID);
for (unsigned j = NumShared; j != SizePrevIds; ++j) {
SizeAction -= AsmPrinter::SizeSLEB128(PrevAction->ValueForTypeID);
SizeAction += -PrevAction->NextAction;
PrevAction = PrevAction->Previous;
}
}
// Compute the actions.
for (unsigned I = NumShared, M = TypeIds.size(); I != M; ++I) {
int TypeID = TypeIds[I];
assert(-1-TypeID < (int)FilterOffsets.size() && "Unknown filter id!");
int ValueForTypeID = TypeID < 0 ? FilterOffsets[-1 - TypeID] : TypeID;
unsigned SizeTypeID = AsmPrinter::SizeSLEB128(ValueForTypeID);
int NextAction = SizeAction ? -(SizeAction + SizeTypeID) : 0;
SizeAction = SizeTypeID + AsmPrinter::SizeSLEB128(NextAction);
SizeSiteActions += SizeAction;
ActionEntry Action = {ValueForTypeID, NextAction, PrevAction};
Actions.push_back(Action);
PrevAction = &Actions.back();
}
// Record the first action of the landing pad site.
FirstAction = SizeActions + SizeSiteActions - SizeAction + 1;
} // else identical - re-use previous FirstAction
FirstActions.push_back(FirstAction);
// Compute this sites contribution to size.
SizeActions += SizeSiteActions;
}
// Compute the call-site table. Entries must be ordered by address.
SmallVector<CallSiteEntry, 64> CallSites;
RangeMapType PadMap;
for (unsigned i = 0, N = LandingPads.size(); i != N; ++i) {
const LandingPadInfo *LandingPad = LandingPads[i];
for (unsigned j=0, E = LandingPad->BeginLabels.size(); j != E; ++j) {
unsigned BeginLabel = LandingPad->BeginLabels[j];
assert(!PadMap.count(BeginLabel) && "Duplicate landing pad labels!");
PadRange P = { i, j };
PadMap[BeginLabel] = P;
}
}
bool MayThrow = false;
unsigned LastLabel = 0;
for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
I != E; ++I) {
for (MachineBasicBlock::const_iterator MI = I->begin(), E = I->end();
MI != E; ++MI) {
if (MI->getOpcode() != TargetInstrInfo::LABEL) {
MayThrow |= MI->getDesc().isCall();
continue;
}
unsigned BeginLabel = MI->getOperand(0).getImm();
assert(BeginLabel && "Invalid label!");
if (BeginLabel == LastLabel)
MayThrow = false;
RangeMapType::iterator L = PadMap.find(BeginLabel);
if (L == PadMap.end())
continue;
PadRange P = L->second;
const LandingPadInfo *LandingPad = LandingPads[P.PadIndex];
assert(BeginLabel == LandingPad->BeginLabels[P.RangeIndex] &&
"Inconsistent landing pad map!");
// If some instruction between the previous try-range and this one may
// throw, create a call-site entry with no landing pad for the region
// between the try-ranges.
if (MayThrow) {
CallSiteEntry Site = {LastLabel, BeginLabel, 0, 0};
CallSites.push_back(Site);
}
LastLabel = LandingPad->EndLabels[P.RangeIndex];
CallSiteEntry Site = {BeginLabel, LastLabel,
LandingPad->LandingPadLabel, FirstActions[P.PadIndex]};
assert(Site.BeginLabel && Site.EndLabel && Site.PadLabel &&
"Invalid landing pad!");
// Try to merge with the previous call-site.
if (CallSites.size()) {
CallSiteEntry &Prev = CallSites[CallSites.size()-1];
if (Site.PadLabel == Prev.PadLabel && Site.Action == Prev.Action) {
// Extend the range of the previous entry.
Prev.EndLabel = Site.EndLabel;
continue;
}
}
// Otherwise, create a new call-site.
CallSites.push_back(Site);
}
}
// If some instruction between the previous try-range and the end of the
// function may throw, create a call-site entry with no landing pad for the
// region following the try-range.
if (MayThrow) {
CallSiteEntry Site = {LastLabel, 0, 0, 0};
CallSites.push_back(Site);
}
// Final tallies.
unsigned SizeSites = CallSites.size() * (sizeof(int32_t) + // Site start.
sizeof(int32_t) + // Site length.
sizeof(int32_t)); // Landing pad.
for (unsigned i = 0, e = CallSites.size(); i < e; ++i)
SizeSites += AsmPrinter::SizeULEB128(CallSites[i].Action);
unsigned SizeTypes = TypeInfos.size() * TD->getPointerSize();
unsigned TypeOffset = sizeof(int8_t) + // Call site format
// Call-site table length
AsmPrinter::SizeULEB128(SizeSites) +
SizeSites + SizeActions + SizeTypes;
unsigned TotalSize = sizeof(int8_t) + // LPStart format
sizeof(int8_t) + // TType format
AsmPrinter::SizeULEB128(TypeOffset) + // TType base offset
TypeOffset;
unsigned SizeAlign = (4 - TotalSize) & 3;
// Begin the exception table.
FinalSize = RoundUpToAlign(FinalSize, 4);
for (unsigned i = 0; i != SizeAlign; ++i) {
++FinalSize;
}
unsigned PointerSize = TD->getPointerSize();
// Emit the header.
++FinalSize;
// Asm->EOL("LPStart format (DW_EH_PE_omit)");
++FinalSize;
// Asm->EOL("TType format (DW_EH_PE_absptr)");
++FinalSize;
// Asm->EOL("TType base offset");
++FinalSize;
// Asm->EOL("Call site format (DW_EH_PE_udata4)");
++FinalSize;
// Asm->EOL("Call-site table length");
// Emit the landing pad site information.
for (unsigned i = 0; i < CallSites.size(); ++i) {
CallSiteEntry &S = CallSites[i];
// Asm->EOL("Region start");
FinalSize += PointerSize;
//Asm->EOL("Region length");
FinalSize += PointerSize;
// Asm->EOL("Landing pad");
FinalSize += PointerSize;
FinalSize += AsmPrinter::SizeULEB128(S.Action);
// Asm->EOL("Action");
}
// Emit the actions.
for (unsigned I = 0, N = Actions.size(); I != N; ++I) {
ActionEntry &Action = Actions[I];
//Asm->EOL("TypeInfo index");
FinalSize += AsmPrinter::SizeSLEB128(Action.ValueForTypeID);
//Asm->EOL("Next action");
FinalSize += AsmPrinter::SizeSLEB128(Action.NextAction);
}
// Emit the type ids.
for (unsigned M = TypeInfos.size(); M; --M) {
// Asm->EOL("TypeInfo");
FinalSize += PointerSize;
}
// Emit the filter typeids.
for (unsigned j = 0, M = FilterIds.size(); j < M; ++j) {
unsigned TypeID = FilterIds[j];
FinalSize += AsmPrinter::SizeULEB128(TypeID);
//Asm->EOL("Filter TypeInfo index");
}
FinalSize = RoundUpToAlign(FinalSize, 4);
return FinalSize;
}
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