llvm-6502/include/llvm/MC/MCAssembler.h

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//===- MCAssembler.h - Object File Generation -------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_MC_MCASSEMBLER_H
#define LLVM_MC_MCASSEMBLER_H
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/ilist.h"
#include "llvm/ADT/ilist_node.h"
#include "llvm/Support/Casting.h"
#include "llvm/MC/MCFixup.h"
#include "llvm/MC/MCInst.h"
#include "llvm/System/DataTypes.h"
#include <vector> // FIXME: Shouldn't be needed.
namespace llvm {
class raw_ostream;
class MCAsmLayout;
class MCAssembler;
class MCContext;
class MCCodeEmitter;
class MCExpr;
class MCFragment;
class MCObjectWriter;
class MCSection;
class MCSectionData;
class MCSymbol;
class MCValue;
class TargetAsmBackend;
/// MCAsmFixup - Represent a fixed size region of bytes inside some fragment
/// which needs to be rewritten. This region will either be rewritten by the
/// assembler or cause a relocation entry to be generated.
//
// FIXME: This should probably just be merged with MCFixup.
class MCAsmFixup {
public:
/// Offset - The offset inside the fragment which needs to be rewritten.
uint64_t Offset;
/// Value - The expression to eventually write into the fragment.
const MCExpr *Value;
/// Kind - The fixup kind.
MCFixupKind Kind;
public:
MCAsmFixup(uint64_t _Offset, const MCExpr &_Value, MCFixupKind _Kind)
: Offset(_Offset), Value(&_Value), Kind(_Kind) {}
};
class MCFragment : public ilist_node<MCFragment> {
friend class MCAsmLayout;
MCFragment(const MCFragment&); // DO NOT IMPLEMENT
void operator=(const MCFragment&); // DO NOT IMPLEMENT
public:
enum FragmentType {
FT_Align,
FT_Data,
FT_Fill,
FT_Inst,
FT_Org,
FT_ZeroFill
};
private:
FragmentType Kind;
/// Parent - The data for the section this fragment is in.
MCSectionData *Parent;
/// @name Assembler Backend Data
/// @{
//
// FIXME: This could all be kept private to the assembler implementation.
/// Offset - The offset of this fragment in its section. This is ~0 until
/// initialized.
uint64_t Offset;
/// EffectiveSize - The compute size of this section. This is ~0 until
/// initialized.
uint64_t EffectiveSize;
/// Ordinal - The global index of this fragment. This is the index across all
/// sections, not just the parent section.
unsigned Ordinal;
/// @}
protected:
MCFragment(FragmentType _Kind, MCSectionData *_Parent = 0);
public:
// Only for sentinel.
MCFragment();
virtual ~MCFragment();
FragmentType getKind() const { return Kind; }
MCSectionData *getParent() const { return Parent; }
void setParent(MCSectionData *Value) { Parent = Value; }
unsigned getOrdinal() const { return Ordinal; }
void setOrdinal(unsigned Value) { Ordinal = Value; }
static bool classof(const MCFragment *O) { return true; }
virtual void dump();
};
class MCDataFragment : public MCFragment {
SmallString<32> Contents;
/// Fixups - The list of fixups in this fragment.
std::vector<MCAsmFixup> Fixups;
public:
typedef std::vector<MCAsmFixup>::const_iterator const_fixup_iterator;
typedef std::vector<MCAsmFixup>::iterator fixup_iterator;
public:
MCDataFragment(MCSectionData *SD = 0) : MCFragment(FT_Data, SD) {}
/// @name Accessors
/// @{
SmallString<32> &getContents() { return Contents; }
const SmallString<32> &getContents() const { return Contents; }
/// @}
/// @name Fixup Access
/// @{
void addFixup(MCAsmFixup Fixup) {
// Enforce invariant that fixups are in offset order.
assert((Fixups.empty() || Fixup.Offset > Fixups.back().Offset) &&
"Fixups must be added in order!");
Fixups.push_back(Fixup);
}
std::vector<MCAsmFixup> &getFixups() { return Fixups; }
const std::vector<MCAsmFixup> &getFixups() const { return Fixups; }
fixup_iterator fixup_begin() { return Fixups.begin(); }
const_fixup_iterator fixup_begin() const { return Fixups.begin(); }
fixup_iterator fixup_end() {return Fixups.end();}
const_fixup_iterator fixup_end() const {return Fixups.end();}
size_t fixup_size() const { return Fixups.size(); }
/// @}
static bool classof(const MCFragment *F) {
return F->getKind() == MCFragment::FT_Data;
}
static bool classof(const MCDataFragment *) { return true; }
virtual void dump();
};
// FIXME: This current incarnation of MCInstFragment doesn't make much sense, as
// it is almost entirely a duplicate of MCDataFragment. If we decide to stick
// with this approach (as opposed to making MCInstFragment a very light weight
// object with just the MCInst and a code size, then we should just change
// MCDataFragment to have an optional MCInst at its end.
class MCInstFragment : public MCFragment {
/// Inst - The instruction this is a fragment for.
MCInst Inst;
/// InstSize - The size of the currently encoded instruction.
SmallString<8> Code;
/// Fixups - The list of fixups in this fragment.
SmallVector<MCAsmFixup, 1> Fixups;
public:
typedef SmallVectorImpl<MCAsmFixup>::const_iterator const_fixup_iterator;
typedef SmallVectorImpl<MCAsmFixup>::iterator fixup_iterator;
public:
MCInstFragment(MCInst _Inst, MCSectionData *SD = 0)
: MCFragment(FT_Inst, SD), Inst(_Inst) {
}
/// @name Accessors
/// @{
SmallVectorImpl<char> &getCode() { return Code; }
const SmallVectorImpl<char> &getCode() const { return Code; }
unsigned getInstSize() const { return Code.size(); }
MCInst &getInst() { return Inst; }
const MCInst &getInst() const { return Inst; }
void setInst(MCInst Value) { Inst = Value; }
/// @}
/// @name Fixup Access
/// @{
SmallVectorImpl<MCAsmFixup> &getFixups() { return Fixups; }
const SmallVectorImpl<MCAsmFixup> &getFixups() const { return Fixups; }
fixup_iterator fixup_begin() { return Fixups.begin(); }
const_fixup_iterator fixup_begin() const { return Fixups.begin(); }
fixup_iterator fixup_end() {return Fixups.end();}
const_fixup_iterator fixup_end() const {return Fixups.end();}
size_t fixup_size() const { return Fixups.size(); }
/// @}
static bool classof(const MCFragment *F) {
return F->getKind() == MCFragment::FT_Inst;
}
static bool classof(const MCInstFragment *) { return true; }
virtual void dump();
};
class MCAlignFragment : public MCFragment {
/// Alignment - The alignment to ensure, in bytes.
unsigned Alignment;
/// Value - Value to use for filling padding bytes.
int64_t Value;
/// ValueSize - The size of the integer (in bytes) of \arg Value.
unsigned ValueSize;
/// MaxBytesToEmit - The maximum number of bytes to emit; if the alignment
/// cannot be satisfied in this width then this fragment is ignored.
unsigned MaxBytesToEmit;
/// EmitNops - true when aligning code and optimal nops to be used for
/// filling.
bool EmitNops;
public:
MCAlignFragment(unsigned _Alignment, int64_t _Value, unsigned _ValueSize,
unsigned _MaxBytesToEmit, bool _EmitNops,
MCSectionData *SD = 0)
: MCFragment(FT_Align, SD), Alignment(_Alignment),
Value(_Value),ValueSize(_ValueSize),
MaxBytesToEmit(_MaxBytesToEmit), EmitNops(_EmitNops) {}
/// @name Accessors
/// @{
unsigned getAlignment() const { return Alignment; }
int64_t getValue() const { return Value; }
unsigned getValueSize() const { return ValueSize; }
unsigned getMaxBytesToEmit() const { return MaxBytesToEmit; }
unsigned getEmitNops() const { return EmitNops; }
/// @}
static bool classof(const MCFragment *F) {
return F->getKind() == MCFragment::FT_Align;
}
static bool classof(const MCAlignFragment *) { return true; }
virtual void dump();
};
class MCFillFragment : public MCFragment {
/// Value - Value to use for filling bytes.
int64_t Value;
/// ValueSize - The size (in bytes) of \arg Value to use when filling.
unsigned ValueSize;
/// Count - The number of copies of \arg Value to insert.
uint64_t Count;
public:
MCFillFragment(int64_t _Value, unsigned _ValueSize, uint64_t _Count,
MCSectionData *SD = 0)
: MCFragment(FT_Fill, SD),
Value(_Value), ValueSize(_ValueSize), Count(_Count) {}
/// @name Accessors
/// @{
int64_t getValue() const { return Value; }
unsigned getValueSize() const { return ValueSize; }
uint64_t getCount() const { return Count; }
/// @}
static bool classof(const MCFragment *F) {
return F->getKind() == MCFragment::FT_Fill;
}
static bool classof(const MCFillFragment *) { return true; }
virtual void dump();
};
class MCOrgFragment : public MCFragment {
/// Offset - The offset this fragment should start at.
const MCExpr *Offset;
/// Value - Value to use for filling bytes.
int8_t Value;
public:
MCOrgFragment(const MCExpr &_Offset, int8_t _Value, MCSectionData *SD = 0)
: MCFragment(FT_Org, SD),
Offset(&_Offset), Value(_Value) {}
/// @name Accessors
/// @{
const MCExpr &getOffset() const { return *Offset; }
uint8_t getValue() const { return Value; }
/// @}
static bool classof(const MCFragment *F) {
return F->getKind() == MCFragment::FT_Org;
}
static bool classof(const MCOrgFragment *) { return true; }
virtual void dump();
};
/// MCZeroFillFragment - Represent data which has a fixed size and alignment,
/// but requires no physical space in the object file.
class MCZeroFillFragment : public MCFragment {
/// Size - The size of this fragment.
uint64_t Size;
/// Alignment - The alignment for this fragment.
unsigned Alignment;
public:
MCZeroFillFragment(uint64_t _Size, unsigned _Alignment, MCSectionData *SD = 0)
: MCFragment(FT_ZeroFill, SD),
Size(_Size), Alignment(_Alignment) {}
/// @name Accessors
/// @{
uint64_t getSize() const { return Size; }
unsigned getAlignment() const { return Alignment; }
/// @}
static bool classof(const MCFragment *F) {
return F->getKind() == MCFragment::FT_ZeroFill;
}
static bool classof(const MCZeroFillFragment *) { return true; }
virtual void dump();
};
// FIXME: Should this be a separate class, or just merged into MCSection? Since
// we anticipate the fast path being through an MCAssembler, the only reason to
// keep it out is for API abstraction.
class MCSectionData : public ilist_node<MCSectionData> {
friend class MCAsmLayout;
MCSectionData(const MCSectionData&); // DO NOT IMPLEMENT
void operator=(const MCSectionData&); // DO NOT IMPLEMENT
public:
typedef iplist<MCFragment> FragmentListType;
typedef FragmentListType::const_iterator const_iterator;
typedef FragmentListType::iterator iterator;
typedef FragmentListType::const_reverse_iterator const_reverse_iterator;
typedef FragmentListType::reverse_iterator reverse_iterator;
private:
iplist<MCFragment> Fragments;
const MCSection *Section;
/// Ordinal - The section index in the assemblers section list.
unsigned Ordinal;
/// Alignment - The maximum alignment seen in this section.
unsigned Alignment;
/// @name Assembler Backend Data
/// @{
//
// FIXME: This could all be kept private to the assembler implementation.
/// Address - The computed address of this section. This is ~0 until
/// initialized.
uint64_t Address;
/// Size - The content size of this section. This is ~0 until initialized.
uint64_t Size;
/// FileSize - The size of this section in the object file. This is ~0 until
/// initialized.
uint64_t FileSize;
/// HasInstructions - Whether this section has had instructions emitted into
/// it.
unsigned HasInstructions : 1;
/// @}
public:
// Only for use as sentinel.
MCSectionData();
MCSectionData(const MCSection &Section, MCAssembler *A = 0);
const MCSection &getSection() const { return *Section; }
unsigned getAlignment() const { return Alignment; }
void setAlignment(unsigned Value) { Alignment = Value; }
bool hasInstructions() const { return HasInstructions; }
void setHasInstructions(bool Value) { HasInstructions = Value; }
unsigned getOrdinal() const { return Ordinal; }
void setOrdinal(unsigned Value) { Ordinal = Value; }
/// @name Fragment Access
/// @{
const FragmentListType &getFragmentList() const { return Fragments; }
FragmentListType &getFragmentList() { return Fragments; }
iterator begin() { return Fragments.begin(); }
const_iterator begin() const { return Fragments.begin(); }
iterator end() { return Fragments.end(); }
const_iterator end() const { return Fragments.end(); }
reverse_iterator rbegin() { return Fragments.rbegin(); }
const_reverse_iterator rbegin() const { return Fragments.rbegin(); }
reverse_iterator rend() { return Fragments.rend(); }
const_reverse_iterator rend() const { return Fragments.rend(); }
size_t size() const { return Fragments.size(); }
bool empty() const { return Fragments.empty(); }
void dump();
/// @}
};
// FIXME: Same concerns as with SectionData.
class MCSymbolData : public ilist_node<MCSymbolData> {
public:
const MCSymbol *Symbol;
/// Fragment - The fragment this symbol's value is relative to, if any.
MCFragment *Fragment;
/// Offset - The offset to apply to the fragment address to form this symbol's
/// value.
uint64_t Offset;
/// IsExternal - True if this symbol is visible outside this translation
/// unit.
unsigned IsExternal : 1;
/// IsPrivateExtern - True if this symbol is private extern.
unsigned IsPrivateExtern : 1;
/// CommonSize - The size of the symbol, if it is 'common', or 0.
//
// FIXME: Pack this in with other fields? We could put it in offset, since a
// common symbol can never get a definition.
uint64_t CommonSize;
/// CommonAlign - The alignment of the symbol, if it is 'common'.
//
// FIXME: Pack this in with other fields?
unsigned CommonAlign;
/// Flags - The Flags field is used by object file implementations to store
/// additional per symbol information which is not easily classified.
uint32_t Flags;
/// Index - Index field, for use by the object file implementation.
uint64_t Index;
public:
// Only for use as sentinel.
MCSymbolData();
MCSymbolData(const MCSymbol &_Symbol, MCFragment *_Fragment, uint64_t _Offset,
MCAssembler *A = 0);
/// @name Accessors
/// @{
const MCSymbol &getSymbol() const { return *Symbol; }
MCFragment *getFragment() const { return Fragment; }
void setFragment(MCFragment *Value) { Fragment = Value; }
uint64_t getOffset() const { return Offset; }
void setOffset(uint64_t Value) { Offset = Value; }
/// @}
/// @name Symbol Attributes
/// @{
bool isExternal() const { return IsExternal; }
void setExternal(bool Value) { IsExternal = Value; }
bool isPrivateExtern() const { return IsPrivateExtern; }
void setPrivateExtern(bool Value) { IsPrivateExtern = Value; }
/// isCommon - Is this a 'common' symbol.
bool isCommon() const { return CommonSize != 0; }
/// setCommon - Mark this symbol as being 'common'.
///
/// \param Size - The size of the symbol.
/// \param Align - The alignment of the symbol.
void setCommon(uint64_t Size, unsigned Align) {
CommonSize = Size;
CommonAlign = Align;
}
/// getCommonSize - Return the size of a 'common' symbol.
uint64_t getCommonSize() const {
assert(isCommon() && "Not a 'common' symbol!");
return CommonSize;
}
/// getCommonAlignment - Return the alignment of a 'common' symbol.
unsigned getCommonAlignment() const {
assert(isCommon() && "Not a 'common' symbol!");
return CommonAlign;
}
/// getFlags - Get the (implementation defined) symbol flags.
uint32_t getFlags() const { return Flags; }
/// setFlags - Set the (implementation defined) symbol flags.
void setFlags(uint32_t Value) { Flags = Value; }
/// getIndex - Get the (implementation defined) index.
uint64_t getIndex() const { return Index; }
/// setIndex - Set the (implementation defined) index.
void setIndex(uint64_t Value) { Index = Value; }
/// @}
void dump();
};
// FIXME: This really doesn't belong here. See comments below.
struct IndirectSymbolData {
MCSymbol *Symbol;
MCSectionData *SectionData;
};
class MCAssembler {
friend class MCAsmLayout;
public:
typedef iplist<MCSectionData> SectionDataListType;
typedef iplist<MCSymbolData> SymbolDataListType;
typedef SectionDataListType::const_iterator const_iterator;
typedef SectionDataListType::iterator iterator;
typedef SymbolDataListType::const_iterator const_symbol_iterator;
typedef SymbolDataListType::iterator symbol_iterator;
typedef std::vector<IndirectSymbolData>::const_iterator
const_indirect_symbol_iterator;
typedef std::vector<IndirectSymbolData>::iterator indirect_symbol_iterator;
private:
MCAssembler(const MCAssembler&); // DO NOT IMPLEMENT
void operator=(const MCAssembler&); // DO NOT IMPLEMENT
MCContext &Context;
TargetAsmBackend &Backend;
MCCodeEmitter &Emitter;
raw_ostream &OS;
iplist<MCSectionData> Sections;
iplist<MCSymbolData> Symbols;
/// The map of sections to their associated assembler backend data.
//
// FIXME: Avoid this indirection?
DenseMap<const MCSection*, MCSectionData*> SectionMap;
/// The map of symbols to their associated assembler backend data.
//
// FIXME: Avoid this indirection?
DenseMap<const MCSymbol*, MCSymbolData*> SymbolMap;
std::vector<IndirectSymbolData> IndirectSymbols;
unsigned RelaxAll : 1;
unsigned SubsectionsViaSymbols : 1;
private:
/// Evaluate a fixup to a relocatable expression and the value which should be
/// placed into the fixup.
///
/// \param Layout The layout to use for evaluation.
/// \param Fixup The fixup to evaluate.
/// \param DF The fragment the fixup is inside.
/// \param Target [out] On return, the relocatable expression the fixup
/// evaluates to.
/// \param Value [out] On return, the value of the fixup as currently layed
/// out.
/// \return Whether the fixup value was fully resolved. This is true if the
/// \arg Value result is fixed, otherwise the value may change due to
/// relocation.
bool EvaluateFixup(const MCAsmLayout &Layout,
const MCAsmFixup &Fixup, const MCFragment *DF,
MCValue &Target, uint64_t &Value) const;
/// Check whether a fixup can be satisfied, or whether it needs to be relaxed
/// (increased in size, in order to hold its value correctly).
bool FixupNeedsRelaxation(const MCAsmFixup &Fixup, const MCFragment *DF,
const MCAsmLayout &Layout) const;
/// Check whether the given fragment needs relaxation.
bool FragmentNeedsRelaxation(const MCInstFragment *IF,
const MCAsmLayout &Layout) const;
/// LayoutSection - Assign the section the given \arg StartAddress, and then
/// assign offsets and sizes to the fragments in the section \arg SD, and
/// update the section size.
///
/// \return The address at the end of the section, for use in laying out the
/// succeeding section.
uint64_t LayoutSection(MCSectionData &SD, MCAsmLayout &Layout,
uint64_t StartAddress);
/// LayoutOnce - Perform one layout iteration and return true if any offsets
/// were adjusted.
bool LayoutOnce(MCAsmLayout &Layout);
/// FinishLayout - Finalize a layout, including fragment lowering.
void FinishLayout(MCAsmLayout &Layout);
public:
/// Find the symbol which defines the atom containing given address, inside
/// the given section, or null if there is no such symbol.
//
// FIXME-PERF: Eliminate this, it is very slow.
const MCSymbolData *getAtomForAddress(const MCAsmLayout &Layout,
const MCSectionData *Section,
uint64_t Address) const;
/// Find the symbol which defines the atom containing the given symbol, or
/// null if there is no such symbol.
//
// FIXME-PERF: Eliminate this, it is very slow.
const MCSymbolData *getAtom(const MCAsmLayout &Layout,
const MCSymbolData *Symbol) const;
/// Check whether a particular symbol is visible to the linker and is required
/// in the symbol table, or whether it can be discarded by the assembler. This
/// also effects whether the assembler treats the label as potentially
/// defining a separate atom.
bool isSymbolLinkerVisible(const MCSymbolData *SD) const;
/// Emit the section contents using the given object writer.
//
// FIXME: Should MCAssembler always have a reference to the object writer?
void WriteSectionData(const MCSectionData *Section, const MCAsmLayout &Layout,
MCObjectWriter *OW) const;
public:
/// Construct a new assembler instance.
///
/// \arg OS - The stream to output to.
//
// FIXME: How are we going to parameterize this? Two obvious options are stay
// concrete and require clients to pass in a target like object. The other
// option is to make this abstract, and have targets provide concrete
// implementations as we do with AsmParser.
MCAssembler(MCContext &_Context, TargetAsmBackend &_Backend,
MCCodeEmitter &_Emitter, raw_ostream &OS);
~MCAssembler();
MCContext &getContext() const { return Context; }
TargetAsmBackend &getBackend() const { return Backend; }
MCCodeEmitter &getEmitter() const { return Emitter; }
/// Finish - Do final processing and write the object to the output stream.
void Finish();
// FIXME: This does not belong here.
bool getSubsectionsViaSymbols() const {
return SubsectionsViaSymbols;
}
void setSubsectionsViaSymbols(bool Value) {
SubsectionsViaSymbols = Value;
}
bool getRelaxAll() const { return RelaxAll; }
void setRelaxAll(bool Value) { RelaxAll = Value; }
/// @name Section List Access
/// @{
const SectionDataListType &getSectionList() const { return Sections; }
SectionDataListType &getSectionList() { return Sections; }
iterator begin() { return Sections.begin(); }
const_iterator begin() const { return Sections.begin(); }
iterator end() { return Sections.end(); }
const_iterator end() const { return Sections.end(); }
size_t size() const { return Sections.size(); }
/// @}
/// @name Symbol List Access
/// @{
const SymbolDataListType &getSymbolList() const { return Symbols; }
SymbolDataListType &getSymbolList() { return Symbols; }
symbol_iterator symbol_begin() { return Symbols.begin(); }
const_symbol_iterator symbol_begin() const { return Symbols.begin(); }
symbol_iterator symbol_end() { return Symbols.end(); }
const_symbol_iterator symbol_end() const { return Symbols.end(); }
size_t symbol_size() const { return Symbols.size(); }
/// @}
/// @name Indirect Symbol List Access
/// @{
// FIXME: This is a total hack, this should not be here. Once things are
// factored so that the streamer has direct access to the .o writer, it can
// disappear.
std::vector<IndirectSymbolData> &getIndirectSymbols() {
return IndirectSymbols;
}
indirect_symbol_iterator indirect_symbol_begin() {
return IndirectSymbols.begin();
}
const_indirect_symbol_iterator indirect_symbol_begin() const {
return IndirectSymbols.begin();
}
indirect_symbol_iterator indirect_symbol_end() {
return IndirectSymbols.end();
}
const_indirect_symbol_iterator indirect_symbol_end() const {
return IndirectSymbols.end();
}
size_t indirect_symbol_size() const { return IndirectSymbols.size(); }
/// @}
/// @name Backend Data Access
/// @{
MCSectionData &getSectionData(const MCSection &Section) const {
MCSectionData *Entry = SectionMap.lookup(&Section);
assert(Entry && "Missing section data!");
return *Entry;
}
MCSectionData &getOrCreateSectionData(const MCSection &Section,
bool *Created = 0) {
MCSectionData *&Entry = SectionMap[&Section];
if (Created) *Created = !Entry;
if (!Entry)
Entry = new MCSectionData(Section, this);
return *Entry;
}
MCSymbolData &getSymbolData(const MCSymbol &Symbol) const {
MCSymbolData *Entry = SymbolMap.lookup(&Symbol);
assert(Entry && "Missing symbol data!");
return *Entry;
}
MCSymbolData &getOrCreateSymbolData(const MCSymbol &Symbol,
bool *Created = 0) {
MCSymbolData *&Entry = SymbolMap[&Symbol];
if (Created) *Created = !Entry;
if (!Entry)
Entry = new MCSymbolData(Symbol, 0, 0, this);
return *Entry;
}
/// @}
void dump();
};
} // end namespace llvm
#endif