//===- 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/Optional.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
#include "llvm/BinaryFormat/Dwarf.h"
#include "llvm/MC/MCAsmMacro.h"
#include "llvm/MC/MCDwarf.h"
#include "llvm/MC/MCSubtargetInfo.h"
#include "llvm/MC/SectionKind.h"
#include "llvm/Support/Allocator.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/MD5.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <cassert>
#include <cstddef>
#include <cstdint>
#include <map>
#include <memory>
#include <string>
#include <utility>
#include <vector>
namespace llvm {
class CodeViewContext;
class MCAsmInfo;
class MCLabel;
class MCObjectFileInfo;
class MCRegisterInfo;
class MCSection;
class MCSectionCOFF;
class MCSectionELF;
class MCSectionMachO;
class MCSectionWasm;
class MCStreamer;
class MCSymbol;
class MCSymbolELF;
class MCSymbolWasm;
class SMLoc;
class SourceMgr;
/// Context object for machine code objects. This class owns all of the
/// sections that it creates.
///
class MCContext {
public:
using SymbolTable = StringMap<MCSymbol *, BumpPtrAllocator &>;
private:
/// The SourceMgr for this object, if any.
const SourceMgr *SrcMgr;
/// The SourceMgr for inline assembly, if any.
SourceMgr *InlineSrcMgr;
/// The MCAsmInfo for this target.
const MCAsmInfo *MAI;
/// The MCRegisterInfo for this target.
const MCRegisterInfo *MRI;
/// The MCObjectFileInfo for this target.
const MCObjectFileInfo *MOFI;
std::unique_ptr<CodeViewContext> CVContext;
/// 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;
SpecificBumpPtrAllocator<MCSectionCOFF> COFFAllocator;
SpecificBumpPtrAllocator<MCSectionELF> ELFAllocator;
SpecificBumpPtrAllocator<MCSectionMachO> MachOAllocator;
SpecificBumpPtrAllocator<MCSectionWasm> WasmAllocator;
/// Bindings of names to symbols.
SymbolTable Symbols;
/// A mapping 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;
/// Keeps tracks of names that were used both for used declared and
/// artificial symbols. The value is "true" if the name has been used for a
/// non-section symbol (there can be at most one of those, plus an unlimited
/// number of section symbols with the same name).
StringMap<bool, BumpPtrAllocator &> UsedNames;
/// The next ID to dole out to an unnamed assembler temporary symbol with
/// a given prefix.
StringMap<unsigned> NextID;
/// 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.
std::unique_ptr<raw_fd_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 = false;
/// The compilation directory to use for DW_AT_comp_dir.
SmallString<128> CompilationDir;
/// Prefix replacement map for source file information.
std::map<const std::string, const std::string> DebugPrefixMap;
/// 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 = false;
/// Generate dwarf debugging info for assembly source files.
bool GenDwarfForAssembly = false;
/// The current dwarf file number when generate dwarf debugging info for
/// assembly source files.
unsigned GenDwarfFileNumber = 0;
/// Sections for generating the .debug_ranges and .debug_aranges sections.
SetVector<MCSection *> SectionsForRanges;
/// 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 = 4;
/// Honor temporary labels, this is useful for debugging semantic
/// differences between temporary and non-temporary labels (primarily on
/// Darwin).
bool AllowTemporaryLabels = true;
bool UseNamesOnTempLabels = true;
/// The Compile Unit ID that we are currently processing.
unsigned DwarfCompileUnitID = 0;
struct ELFSectionKey {
std::string SectionName;
StringRef GroupName;
unsigned UniqueID;
ELFSectionKey(StringRef SectionName, StringRef GroupName,
unsigned UniqueID)
: SectionName(SectionName), GroupName(GroupName), UniqueID(UniqueID) {
}
bool operator<(const ELFSectionKey &Other) const {
if (SectionName != Other.SectionName)
return SectionName < Other.SectionName;
if (GroupName != Other.GroupName)
return GroupName < Other.GroupName;
return UniqueID < Other.UniqueID;
}
};
struct COFFSectionKey {
std::string SectionName;
StringRef GroupName;
int SelectionKey;
unsigned UniqueID;
COFFSectionKey(StringRef SectionName, StringRef GroupName,
int SelectionKey, unsigned UniqueID)
: SectionName(SectionName), GroupName(GroupName),
SelectionKey(SelectionKey), UniqueID(UniqueID) {}
bool operator<(const COFFSectionKey &Other) const {
if (SectionName != Other.SectionName)
return SectionName < Other.SectionName;
if (GroupName != Other.GroupName)
return GroupName < Other.GroupName;
if (SelectionKey != Other.SelectionKey)
return SelectionKey < Other.SelectionKey;
return UniqueID < Other.UniqueID;
}
};
struct WasmSectionKey {
std::string SectionName;
StringRef GroupName;
unsigned UniqueID;
WasmSectionKey(StringRef SectionName, StringRef GroupName,
unsigned UniqueID)
: SectionName(SectionName), GroupName(GroupName), UniqueID(UniqueID) {
}
bool operator<(const WasmSectionKey &Other) const {
if (SectionName != Other.SectionName)
return SectionName < Other.SectionName;
if (GroupName != Other.GroupName)
return GroupName < Other.GroupName;
return UniqueID < Other.UniqueID;
}
};
StringMap<MCSectionMachO *> MachOUniquingMap;
std::map<ELFSectionKey, MCSectionELF *> ELFUniquingMap;
std::map<COFFSectionKey, MCSectionCOFF *> COFFUniquingMap;
std::map<WasmSectionKey, MCSectionWasm *> WasmUniquingMap;
StringMap<bool> RelSecNames;
SpecificBumpPtrAllocator<MCSubtargetInfo> MCSubtargetAllocator;
/// Do automatic reset in destructor
bool AutoReset;
bool HadError = false;
MCSymbol *createSymbolImpl(const StringMapEntry<bool> *Name,
bool CanBeUnnamed);
MCSymbol *createSymbol(StringRef Name, bool AlwaysAddSuffix,
bool IsTemporary);
MCSymbol *getOrCreateDirectionalLocalSymbol(unsigned LocalLabelVal,
unsigned Instance);
MCSectionELF *createELFSectionImpl(StringRef Section, unsigned Type,
unsigned Flags, SectionKind K,
unsigned EntrySize,
const MCSymbolELF *Group,
unsigned UniqueID,
const MCSymbolELF *Associated);
/// Map of currently defined macros.
StringMap<MCAsmMacro> MacroMap;
public:
explicit MCContext(const MCAsmInfo *MAI, const MCRegisterInfo *MRI,
const MCObjectFileInfo *MOFI,
const SourceMgr *Mgr = nullptr, bool DoAutoReset = true);
MCContext(const MCContext &) = delete;
MCContext &operator=(const MCContext &) = delete;
~MCContext();
const SourceMgr *getSourceManager() const { return SrcMgr; }
void setInlineSourceManager(SourceMgr *SM) { InlineSrcMgr = SM; }
const MCAsmInfo *getAsmInfo() const { return MAI; }
const MCRegisterInfo *getRegisterInfo() const { return MRI; }
const MCObjectFileInfo *getObjectFileInfo() const { return MOFI; }
CodeViewContext &getCVContext();
void setAllowTemporaryLabels(bool Value) { AllowTemporaryLabels = Value; }
void setUseNamesOnTempLabels(bool Value) { UseNamesOnTempLabels = 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
/// @{
/// Create and return a new linker temporary symbol with a unique but
/// unspecified name.
MCSymbol *createLinkerPrivateTempSymbol();
/// Create and return a new assembler temporary symbol with a unique but
/// unspecified name.
MCSymbol *createTempSymbol(bool CanBeUnnamed = true);
MCSymbol *createTempSymbol(const Twine &Name, bool AlwaysAddSuffix,
bool CanBeUnnamed = true);
/// 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);
/// 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(const Twine &Name);
/// Gets a symbol that will be defined to the final stack offset of a local
/// variable after codegen.
///
/// \param Idx - The index of a local variable passed to \@llvm.localescape.
MCSymbol *getOrCreateFrameAllocSymbol(StringRef FuncName, unsigned Idx);
MCSymbol *getOrCreateParentFrameOffsetSymbol(StringRef FuncName);
MCSymbol *getOrCreateLSDASymbol(StringRef FuncName);
/// Get the symbol for \p Name, or null.
MCSymbol *lookupSymbol(const Twine &Name) const;
/// Set value for a symbol.
void setSymbolValue(MCStreamer &Streamer, StringRef Sym, uint64_t Val);
/// 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
/// @{
enum : unsigned {
/// Pass this value as the UniqueID during section creation to get the
/// generic section with the given name and characteristics. The usual
/// sections such as .text use this ID.
GenericSectionID = ~0U
};
/// Return the MCSection for the specified mach-o section. This requires
/// the operands to be valid.
MCSectionMachO *getMachOSection(StringRef Segment, StringRef Section,
unsigned TypeAndAttributes,
unsigned Reserved2, SectionKind K,
const char *BeginSymName = nullptr);
MCSectionMachO *getMachOSection(StringRef Segment, StringRef Section,
unsigned TypeAndAttributes, SectionKind K,
const char *BeginSymName = nullptr) {
return getMachOSection(Segment, Section, TypeAndAttributes, 0, K,
BeginSymName);
}
MCSectionELF *getELFSection(const Twine &Section, unsigned Type,
unsigned Flags) {
return getELFSection(Section, Type, Flags, 0, "");
}
MCSectionELF *getELFSection(const Twine &Section, unsigned Type,
unsigned Flags, unsigned EntrySize,
const Twine &Group) {
return getELFSection(Section, Type, Flags, EntrySize, Group, ~0);
}
MCSectionELF *getELFSection(const Twine &Section, unsigned Type,
unsigned Flags, unsigned EntrySize,
const Twine &Group, unsigned UniqueID) {
return getELFSection(Section, Type, Flags, EntrySize, Group, UniqueID,
nullptr);
}
MCSectionELF *getELFSection(const Twine &Section, unsigned Type,
unsigned Flags, unsigned EntrySize,
const Twine &Group, unsigned UniqueID,
const MCSymbolELF *Associated);
MCSectionELF *getELFSection(const Twine &Section, unsigned Type,
unsigned Flags, unsigned EntrySize,
const MCSymbolELF *Group, unsigned UniqueID,
const MCSymbolELF *Associated);
/// Get a section with the provided group identifier. This section is
/// named by concatenating \p Prefix with '.' then \p Suffix. The \p Type
/// describes the type of the section and \p Flags are used to further
/// configure this named section.
MCSectionELF *getELFNamedSection(const Twine &Prefix, const Twine &Suffix,
unsigned Type, unsigned Flags,
unsigned EntrySize = 0);
MCSectionELF *createELFRelSection(const Twine &Name, unsigned Type,
unsigned Flags, unsigned EntrySize,
const MCSymbolELF *Group,
const MCSectionELF *RelInfoSection);
void renameELFSection(MCSectionELF *Section, StringRef Name);
MCSectionELF *createELFGroupSection(const MCSymbolELF *Group);
MCSectionCOFF *getCOFFSection(StringRef Section, unsigned Characteristics,
SectionKind Kind, StringRef COMDATSymName,
int Selection,
unsigned UniqueID = GenericSectionID,
const char *BeginSymName = nullptr);
MCSectionCOFF *getCOFFSection(StringRef Section, unsigned Characteristics,
SectionKind Kind,
const char *BeginSymName = nullptr);
MCSectionCOFF *getCOFFSection(StringRef Section);
/// Gets or creates a section equivalent to Sec that is associated with the
/// section containing KeySym. For example, to create a debug info section
/// associated with an inline function, pass the normal debug info section
/// as Sec and the function symbol as KeySym.
MCSectionCOFF *
getAssociativeCOFFSection(MCSectionCOFF *Sec, const MCSymbol *KeySym,
unsigned UniqueID = GenericSectionID);
MCSectionWasm *getWasmSection(const Twine &Section, SectionKind K) {
return getWasmSection(Section, K, nullptr);
}
MCSectionWasm *getWasmSection(const Twine &Section, SectionKind K,
const char *BeginSymName) {
return getWasmSection(Section, K, "", ~0, BeginSymName);
}
MCSectionWasm *getWasmSection(const Twine &Section, SectionKind K,
const Twine &Group, unsigned UniqueID) {
return getWasmSection(Section, K, Group, UniqueID, nullptr);
}
MCSectionWasm *getWasmSection(const Twine &Section, SectionKind K,
const Twine &Group, unsigned UniqueID,
const char *BeginSymName);
MCSectionWasm *getWasmSection(const Twine &Section, SectionKind K,
const MCSymbolWasm *Group, unsigned UniqueID,
const char *BeginSymName);
// Create and save a copy of STI and return a reference to the copy.
MCSubtargetInfo &getSubtargetCopy(const MCSubtargetInfo &STI);
/// @}
/// \name Dwarf Management
/// @{
/// Get the compilation directory for DW_AT_comp_dir
/// The compilation directory should be set with \c setCompilationDir before
/// calling this function. If it is unset, an empty string will be returned.
StringRef getCompilationDir() const { return CompilationDir; }
/// Set the compilation directory for DW_AT_comp_dir
void setCompilationDir(StringRef S) { CompilationDir = S.str(); }
/// Get the debug prefix map.
const std::map<const std::string, const std::string> &
getDebugPrefixMap() const {
return DebugPrefixMap;
}
/// Add an entry to the debug prefix map.
void addDebugPrefixMapEntry(const std::string &From, const std::string &To);
// Remaps all debug directory paths in-place as per the debug prefix map.
void RemapDebugPaths();
/// 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; }
/// Set the main file name and override the default.
void setMainFileName(StringRef S) { MainFileName = S; }
/// Creates an entry in the dwarf file and directory tables.
Expected<unsigned> getDwarfFile(StringRef Directory, StringRef FileName,
unsigned FileNumber,
MD5::MD5Result *Checksum,
Optional<StringRef> Source, 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;
}
/// Specifies the "root" file and directory of the compilation unit.
/// These are "file 0" and "directory 0" in DWARF v5.
void setMCLineTableRootFile(unsigned CUID, StringRef CompilationDir,
StringRef Filename, MD5::MD5Result *Checksum,
Optional<StringRef> Source) {
getMCDwarfLineTable(CUID).setRootFile(CompilationDir, Filename, Checksum,
Source);
}
/// Reports whether MD5 checksum usage is consistent (all-or-none).
bool isDwarfMD5UsageConsistent(unsigned CUID) const {
return getMCDwarfLineTable(CUID).isMD5UsageConsistent();
}
/// 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;
}
const SetVector<MCSection *> &getGenDwarfSectionSyms() {
return SectionsForRanges;
}
bool addGenDwarfSection(MCSection *Sec) {
return SectionsForRanges.insert(Sec);
}
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; }
dwarf::DwarfFormat getDwarfFormat() const {
// TODO: Support DWARF64
return dwarf::DWARF32;
}
void setDwarfVersion(uint16_t v) { DwarfVersion = v; }
uint16_t getDwarfVersion() const { return DwarfVersion; }
/// @}
char *getSecureLogFile() { return SecureLogFile; }
raw_fd_ostream *getSecureLog() { return SecureLog.get(); }
void setSecureLog(std::unique_ptr<raw_fd_ostream> Value) {
SecureLog = std::move(Value);
}
bool getSecureLogUsed() { return SecureLogUsed; }
void setSecureLogUsed(bool Value) { SecureLogUsed = Value; }
void *allocate(unsigned Size, unsigned Align = 8) {
return Allocator.Allocate(Size, Align);
}
void deallocate(void *Ptr) {}
bool hadError() { return HadError; }
void reportError(SMLoc L, const Twine &Msg);
// 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 reportFatalError(SMLoc L,
const Twine &Msg);
const MCAsmMacro *lookupMacro(StringRef Name) {
StringMap<MCAsmMacro>::iterator I = MacroMap.find(Name);
return (I == MacroMap.end()) ? nullptr : &I->getValue();
}
void defineMacro(StringRef Name, MCAsmMacro Macro) {
MacroMap.insert(std::make_pair(Name, std::move(Macro)));
}
void undefineMacro(StringRef Name) { MacroMap.erase(Name); }
};
} // end namespace llvm
// operator new and delete aren't allowed inside namespaces.
// The throw specifications are mandated by the standard.
/// 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 (8)
/// IntegerLiteral *Ex = new (Context) IntegerLiteral(arguments);
/// // Specific alignment
/// IntegerLiteral *Ex2 = new (Context, 4) 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 = 8) noexcept {
return C.allocate(Bytes, Alignment);
}
/// 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) noexcept {
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 (8)
/// char *data = new (Context) char[10];
/// // Specific alignment
/// char *data = new (Context, 4) 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 = 8) noexcept {
return C.allocate(Bytes, Alignment);
}
/// 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) noexcept {
C.deallocate(Ptr);
}
#endif // LLVM_MC_MCCONTEXT_H