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

508 lines
19 KiB
C
Raw Normal View History

//===- MCContext.h - Machine Code Context -----------------------*- 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_MCCONTEXT_H
#define LLVM_MC_MCCONTEXT_H
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/MC/MCDwarf.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/SectionKind.h"
#include "llvm/Support/Allocator.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/raw_ostream.h"
#include <map>
#include <tuple>
#include <vector> // FIXME: Shouldn't be needed.
namespace llvm {
class MCAsmInfo;
class MCExpr;
class MCSection;
class MCSymbol;
class MCLabel;
struct MCDwarfFile;
class MCDwarfLoc;
class MCObjectFileInfo;
class MCRegisterInfo;
class MCLineSection;
class SMLoc;
class StringRef;
class Twine;
class MCSectionMachO;
class MCSectionELF;
class MCSectionCOFF;
/// MCContext - Context object for machine code objects. This class owns all
/// of the sections that it creates.
///
class MCContext {
MCContext(const MCContext&) LLVM_DELETED_FUNCTION;
MCContext &operator=(const MCContext&) LLVM_DELETED_FUNCTION;
public:
typedef StringMap<MCSymbol*, BumpPtrAllocator&> SymbolTable;
private:
/// The SourceMgr for this object, if any.
const SourceMgr *SrcMgr;
/// The MCAsmInfo for this target.
const MCAsmInfo *MAI;
/// The MCRegisterInfo for this target.
const MCRegisterInfo *MRI;
/// The MCObjectFileInfo for this target.
const MCObjectFileInfo *MOFI;
/// Allocator - Allocator object used for creating machine code objects.
///
/// We use a bump pointer allocator to avoid the need to track all allocated
/// objects.
BumpPtrAllocator Allocator;
/// Symbols - Bindings of names to symbols.
SymbolTable Symbols;
/// A maping from a local label number and an instance count to a symbol.
/// For example, in the assembly
/// 1:
/// 2:
/// 1:
/// We have three labels represented by the pairs (1, 0), (2, 0) and (1, 1)
DenseMap<std::pair<unsigned, unsigned>, MCSymbol*> LocalSymbols;
/// UsedNames - Keeps tracks of names that were used both for used declared
/// and artificial symbols.
StringMap<bool, BumpPtrAllocator&> UsedNames;
/// NextUniqueID - The next ID to dole out to an unnamed assembler temporary
/// symbol.
unsigned NextUniqueID;
/// Instances of directional local labels.
DenseMap<unsigned, MCLabel *> Instances;
/// NextInstance() creates the next instance of the directional local label
/// for the LocalLabelVal and adds it to the map if needed.
unsigned NextInstance(unsigned LocalLabelVal);
/// GetInstance() gets the current instance of the directional local label
/// for the LocalLabelVal and adds it to the map if needed.
unsigned GetInstance(unsigned LocalLabelVal);
/// The file name of the log file from the environment variable
/// AS_SECURE_LOG_FILE. Which must be set before the .secure_log_unique
/// directive is used or it is an error.
char *SecureLogFile;
/// The stream that gets written to for the .secure_log_unique directive.
raw_ostream *SecureLog;
/// Boolean toggled when .secure_log_unique / .secure_log_reset is seen to
/// catch errors if .secure_log_unique appears twice without
/// .secure_log_reset appearing between them.
bool SecureLogUsed;
/// The compilation directory to use for DW_AT_comp_dir.
SmallString<128> CompilationDir;
/// The main file name if passed in explicitly.
std::string MainFileName;
/// The dwarf file and directory tables from the dwarf .file directive.
/// We now emit a line table for each compile unit. To reduce the prologue
/// size of each line table, the files and directories used by each compile
/// unit are separated.
std::map<unsigned, MCDwarfLineTable> MCDwarfLineTablesCUMap;
/// The current dwarf line information from the last dwarf .loc directive.
MCDwarfLoc CurrentDwarfLoc;
bool DwarfLocSeen;
/// Generate dwarf debugging info for assembly source files.
bool GenDwarfForAssembly;
/// The current dwarf file number when generate dwarf debugging info for
/// assembly source files.
unsigned GenDwarfFileNumber;
/// Symbols created for the start and end of each section, used for
/// generating the .debug_ranges and .debug_aranges sections.
MapVector<const MCSection *, std::pair<MCSymbol *, MCSymbol *> >
SectionStartEndSyms;
/// The information gathered from labels that will have dwarf label
/// entries when generating dwarf assembly source files.
std::vector<MCGenDwarfLabelEntry> MCGenDwarfLabelEntries;
/// The string to embed in the debug information for the compile unit, if
/// non-empty.
StringRef DwarfDebugFlags;
/// The string to embed in as the dwarf AT_producer for the compile unit, if
/// non-empty.
StringRef DwarfDebugProducer;
/// The maximum version of dwarf that we should emit.
uint16_t DwarfVersion;
/// Honor temporary labels, this is useful for debugging semantic
/// differences between temporary and non-temporary labels (primarily on
/// Darwin).
bool AllowTemporaryLabels;
/// The Compile Unit ID that we are currently processing.
unsigned DwarfCompileUnitID;
typedef std::pair<std::string, std::string> SectionGroupPair;
typedef std::tuple<std::string, std::string, int> SectionGroupTriple;
StringMap<const MCSectionMachO*> MachOUniquingMap;
std::map<SectionGroupPair, const MCSectionELF *> ELFUniquingMap;
std::map<SectionGroupTriple, const MCSectionCOFF *> COFFUniquingMap;
/// Do automatic reset in destructor
bool AutoReset;
MCSymbol *CreateSymbol(StringRef Name);
MCSymbol *getOrCreateDirectionalLocalSymbol(unsigned LocalLabelVal,
unsigned Instance);
public:
explicit MCContext(const MCAsmInfo *MAI, const MCRegisterInfo *MRI,
const MCObjectFileInfo *MOFI,
const SourceMgr *Mgr = nullptr, bool DoAutoReset = true);
~MCContext();
const SourceMgr *getSourceManager() const { return SrcMgr; }
const MCAsmInfo *getAsmInfo() const { return MAI; }
const MCRegisterInfo *getRegisterInfo() const { return MRI; }
const MCObjectFileInfo *getObjectFileInfo() const { return MOFI; }
void setAllowTemporaryLabels(bool Value) { AllowTemporaryLabels = Value; }
/// @name Module Lifetime Management
/// @{
/// reset - return object to right after construction state to prepare
/// to process a new module
void reset();
/// @}
/// @name Symbol Management
/// @{
/// CreateLinkerPrivateTempSymbol - Create and return a new linker temporary
/// symbol with a unique but unspecified name.
MCSymbol *CreateLinkerPrivateTempSymbol();
/// CreateTempSymbol - Create and return a new assembler temporary symbol
/// with a unique but unspecified name.
MCSymbol *CreateTempSymbol();
/// getUniqueSymbolID() - Return a unique identifier for use in constructing
/// symbol names.
unsigned getUniqueSymbolID() { return NextUniqueID++; }
/// Create the definition of a directional local symbol for numbered label
/// (used for "1:" definitions).
MCSymbol *CreateDirectionalLocalSymbol(unsigned LocalLabelVal);
/// Create and return a directional local symbol for numbered label (used
/// for "1b" or 1f" references).
MCSymbol *GetDirectionalLocalSymbol(unsigned LocalLabelVal, bool Before);
/// GetOrCreateSymbol - Lookup the symbol inside with the specified
/// @p Name. If it exists, return it. If not, create a forward
/// reference and return it.
///
/// @param Name - The symbol name, which must be unique across all symbols.
MCSymbol *GetOrCreateSymbol(StringRef Name);
MCSymbol *GetOrCreateSymbol(const Twine &Name);
/// LookupSymbol - Get the symbol for \p Name, or null.
MCSymbol *LookupSymbol(StringRef Name) const;
MCSymbol *LookupSymbol(const Twine &Name) const;
/// getSymbols - Get a reference for the symbol table for clients that
/// want to, for example, iterate over all symbols. 'const' because we
/// still want any modifications to the table itself to use the MCContext
/// APIs.
const SymbolTable &getSymbols() const {
return Symbols;
}
/// @}
/// @name Section Management
/// @{
/// getMachOSection - Return the MCSection for the specified mach-o section.
/// This requires the operands to be valid.
const MCSectionMachO *getMachOSection(StringRef Segment,
StringRef Section,
unsigned TypeAndAttributes,
unsigned Reserved2,
SectionKind K);
const MCSectionMachO *getMachOSection(StringRef Segment,
StringRef Section,
unsigned TypeAndAttributes,
SectionKind K) {
return getMachOSection(Segment, Section, TypeAndAttributes, 0, K);
}
const MCSectionELF *getELFSection(StringRef Section, unsigned Type,
unsigned Flags, SectionKind Kind);
const MCSectionELF *getELFSection(StringRef Section, unsigned Type,
unsigned Flags, SectionKind Kind,
unsigned EntrySize, StringRef Group);
Reimplement debug info compression by compressing the whole section, rather than a fragment. To support compressing the debug_line section that contains multiple fragments (due, I believe, to variation in choices of line table encoding depending on the size of instruction ranges in the actual program code) we needed to support compressing multiple MCFragments in a single pass. This patch implements that behavior by mutating the post-relaxed and relocated section to be the compressed form of its former self, including renaming the section. This is a more flexible (and less invasive, to a degree) implementation that will allow for other features such as "use compression only if it's smaller than the uncompressed data". Compressing debug_frame would be a possible further extension to this work, but I've left it for now. The hurdle there is alignment sections - which might require going as far as to refactor MCAssembler.cpp:writeFragment to handle writing to a byte buffer or an MCObjectWriter (there's already a virtual call there, so it shouldn't add substantial compile-time cost) which could in turn involve refactoring MCAsmBackend::writeNopData to use that same abstraction... which involves touching all the backends. This would remove the limited handling of fragment writing seen in ELFObjectWriter.cpp:getUncompressedData which would be nice - but it's more invasive. I did discover that I (perhaps obviously) don't need to handle relocations when I rewrite the fragments - since the relocations have already been applied and computed (and stored into ELFObjectWriter::Relocations) by this stage (necessarily, because we need to have written any immediate values or assembly-time relocations into the data already before we compress it, which we have). The test case doesn't necessarily cover that in detail - I can add more test coverage if that's preferred. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205990 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-10 21:53:53 +00:00
void renameELFSection(const MCSectionELF *Section, StringRef Name);
const MCSectionELF *CreateELFGroupSection();
const MCSectionCOFF *getCOFFSection(StringRef Section,
unsigned Characteristics,
SectionKind Kind,
StringRef COMDATSymName, int Selection);
const MCSectionCOFF *getCOFFSection(StringRef Section,
unsigned Characteristics,
SectionKind Kind);
const MCSectionCOFF *getCOFFSection(StringRef Section);
/// @}
/// @name Dwarf Management
/// @{
/// \brief Get the compilation directory for DW_AT_comp_dir
/// This can be overridden by clients which want to control the reported
/// compilation directory and have it be something other than the current
/// working directory.
/// Returns an empty string if the current directory cannot be determined.
StringRef getCompilationDir() const { return CompilationDir; }
/// \brief Set the compilation directory for DW_AT_comp_dir
/// Override the default (CWD) compilation directory.
void setCompilationDir(StringRef S) { CompilationDir = S.str(); }
/// \brief Get the main file name for use in error messages and debug
/// info. This can be set to ensure we've got the correct file name
/// after preprocessing or for -save-temps.
const std::string &getMainFileName() const { return MainFileName; }
/// \brief Set the main file name and override the default.
void setMainFileName(StringRef S) { MainFileName = S; }
/// GetDwarfFile - creates an entry in the dwarf file and directory tables.
unsigned GetDwarfFile(StringRef Directory, StringRef FileName,
unsigned FileNumber, unsigned CUID);
bool isValidDwarfFileNumber(unsigned FileNumber, unsigned CUID = 0);
const std::map<unsigned, MCDwarfLineTable> &getMCDwarfLineTables() const {
return MCDwarfLineTablesCUMap;
}
MCDwarfLineTable &getMCDwarfLineTable(unsigned CUID) {
return MCDwarfLineTablesCUMap[CUID];
}
const MCDwarfLineTable &getMCDwarfLineTable(unsigned CUID) const {
auto I = MCDwarfLineTablesCUMap.find(CUID);
assert(I != MCDwarfLineTablesCUMap.end());
return I->second;
}
const SmallVectorImpl<MCDwarfFile> &getMCDwarfFiles(unsigned CUID = 0) {
return getMCDwarfLineTable(CUID).getMCDwarfFiles();
}
const SmallVectorImpl<std::string> &getMCDwarfDirs(unsigned CUID = 0) {
return getMCDwarfLineTable(CUID).getMCDwarfDirs();
}
bool hasMCLineSections() const {
for (const auto &Table : MCDwarfLineTablesCUMap)
if (!Table.second.getMCDwarfFiles().empty() || Table.second.getLabel())
return true;
return false;
}
unsigned getDwarfCompileUnitID() {
return DwarfCompileUnitID;
}
void setDwarfCompileUnitID(unsigned CUIndex) {
DwarfCompileUnitID = CUIndex;
}
void setMCLineTableCompilationDir(unsigned CUID, StringRef CompilationDir) {
getMCDwarfLineTable(CUID).setCompilationDir(CompilationDir);
}
/// setCurrentDwarfLoc - saves the information from the currently parsed
/// dwarf .loc directive and sets DwarfLocSeen. When the next instruction
/// is assembled an entry in the line number table with this information and
/// the address of the instruction will be created.
void setCurrentDwarfLoc(unsigned FileNum, unsigned Line, unsigned Column,
unsigned Flags, unsigned Isa,
unsigned Discriminator) {
CurrentDwarfLoc.setFileNum(FileNum);
CurrentDwarfLoc.setLine(Line);
CurrentDwarfLoc.setColumn(Column);
CurrentDwarfLoc.setFlags(Flags);
CurrentDwarfLoc.setIsa(Isa);
CurrentDwarfLoc.setDiscriminator(Discriminator);
DwarfLocSeen = true;
}
void ClearDwarfLocSeen() { DwarfLocSeen = false; }
bool getDwarfLocSeen() { return DwarfLocSeen; }
const MCDwarfLoc &getCurrentDwarfLoc() { return CurrentDwarfLoc; }
bool getGenDwarfForAssembly() { return GenDwarfForAssembly; }
void setGenDwarfForAssembly(bool Value) { GenDwarfForAssembly = Value; }
unsigned getGenDwarfFileNumber() { return GenDwarfFileNumber; }
void setGenDwarfFileNumber(unsigned FileNumber) {
GenDwarfFileNumber = FileNumber;
}
MapVector<const MCSection *, std::pair<MCSymbol *, MCSymbol *> > &
getGenDwarfSectionSyms() {
return SectionStartEndSyms;
}
std::pair<MapVector<const MCSection *,
std::pair<MCSymbol *, MCSymbol *> >::iterator,
bool>
addGenDwarfSection(const MCSection *Sec) {
return SectionStartEndSyms.insert(
std::make_pair(Sec, std::make_pair(nullptr, nullptr)));
}
void finalizeDwarfSections(MCStreamer &MCOS);
const std::vector<MCGenDwarfLabelEntry> &getMCGenDwarfLabelEntries() const {
return MCGenDwarfLabelEntries;
}
void addMCGenDwarfLabelEntry(const MCGenDwarfLabelEntry &E) {
MCGenDwarfLabelEntries.push_back(E);
}
void setDwarfDebugFlags(StringRef S) { DwarfDebugFlags = S; }
StringRef getDwarfDebugFlags() { return DwarfDebugFlags; }
void setDwarfDebugProducer(StringRef S) { DwarfDebugProducer = S; }
StringRef getDwarfDebugProducer() { return DwarfDebugProducer; }
void setDwarfVersion(uint16_t v) { DwarfVersion = v; }
uint16_t getDwarfVersion() const { return DwarfVersion; }
/// @}
char *getSecureLogFile() { return SecureLogFile; }
raw_ostream *getSecureLog() { return SecureLog; }
bool getSecureLogUsed() { return SecureLogUsed; }
void setSecureLog(raw_ostream *Value) {
SecureLog = Value;
}
void setSecureLogUsed(bool Value) {
SecureLogUsed = Value;
}
void *Allocate(unsigned Size, unsigned Align = 8) {
return Allocator.Allocate(Size, Align);
}
void Deallocate(void *Ptr) {
}
// Unrecoverable error has occurred. Display the best diagnostic we can
// and bail via exit(1). For now, most MC backend errors are unrecoverable.
// FIXME: We should really do something about that.
LLVM_ATTRIBUTE_NORETURN void FatalError(SMLoc L, const Twine &Msg) const;
};
} // end namespace llvm
// operator new and delete aren't allowed inside namespaces.
// The throw specifications are mandated by the standard.
/// @brief Placement new for using the MCContext's allocator.
///
/// This placement form of operator new uses the MCContext's allocator for
/// obtaining memory. It is a non-throwing new, which means that it returns
/// null on error. (If that is what the allocator does. The current does, so if
/// this ever changes, this operator will have to be changed, too.)
/// Usage looks like this (assuming there's an MCContext 'Context' in scope):
/// @code
/// // Default alignment (16)
/// IntegerLiteral *Ex = new (Context) IntegerLiteral(arguments);
/// // Specific alignment
/// IntegerLiteral *Ex2 = new (Context, 8) IntegerLiteral(arguments);
/// @endcode
/// Please note that you cannot use delete on the pointer; it must be
/// deallocated using an explicit destructor call followed by
/// @c Context.Deallocate(Ptr).
///
/// @param Bytes The number of bytes to allocate. Calculated by the compiler.
/// @param C The MCContext that provides the allocator.
/// @param Alignment The alignment of the allocated memory (if the underlying
/// allocator supports it).
/// @return The allocated memory. Could be NULL.
inline void *operator new(size_t Bytes, llvm::MCContext &C,
size_t Alignment = 16) throw () {
return C.Allocate(Bytes, Alignment);
}
/// @brief Placement delete companion to the new above.
///
/// This operator is just a companion to the new above. There is no way of
/// invoking it directly; see the new operator for more details. This operator
/// is called implicitly by the compiler if a placement new expression using
/// the MCContext throws in the object constructor.
inline void operator delete(void *Ptr, llvm::MCContext &C, size_t)
throw () {
C.Deallocate(Ptr);
}
/// This placement form of operator new[] uses the MCContext's allocator for
/// obtaining memory. It is a non-throwing new[], which means that it returns
/// null on error.
/// Usage looks like this (assuming there's an MCContext 'Context' in scope):
/// @code
/// // Default alignment (16)
/// char *data = new (Context) char[10];
/// // Specific alignment
/// char *data = new (Context, 8) char[10];
/// @endcode
/// Please note that you cannot use delete on the pointer; it must be
/// deallocated using an explicit destructor call followed by
/// @c Context.Deallocate(Ptr).
///
/// @param Bytes The number of bytes to allocate. Calculated by the compiler.
/// @param C The MCContext that provides the allocator.
/// @param Alignment The alignment of the allocated memory (if the underlying
/// allocator supports it).
/// @return The allocated memory. Could be NULL.
inline void *operator new[](size_t Bytes, llvm::MCContext& C,
size_t Alignment = 16) throw () {
return C.Allocate(Bytes, Alignment);
}
/// @brief Placement delete[] companion to the new[] above.
///
/// This operator is just a companion to the new[] above. There is no way of
/// invoking it directly; see the new[] operator for more details. This operator
/// is called implicitly by the compiler if a placement new[] expression using
/// the MCContext throws in the object constructor.
inline void operator delete[](void *Ptr, llvm::MCContext &C) throw () {
C.Deallocate(Ptr);
}
#endif