--- /dev/null
+//===- MCLinkerOptimizationHint.h - LOH interface ---------------*- C++ -*-===//
+//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares some helpers classes to handle Linker Optimization Hint
+// (LOH).
+//
+// FIXME: LOH interface supports only MachO format at the moment.
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_MC_MCLINKEROPTIMIZATIONHINT_H
+#define LLVM_MC_MCLINKEROPTIMIZATIONHINT_H
+
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringSwitch.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/MC/MCMachObjectWriter.h"
+#include "llvm/Support/raw_ostream.h"
+
+namespace llvm {
+
+// Forward declarations.
+class MCAsmLayout;
+class MCSymbol;
+
+/// Linker Optimization Hint Type.
+enum MCLOHType {
+ MCLOH_AdrpAdrp = 0x1u, ///< Adrp xY, _v1@PAGE -> Adrp xY, _v2@PAGE.
+ MCLOH_AdrpLdr = 0x2u, ///< Adrp _v@PAGE -> Ldr _v@PAGEOFF.
+ MCLOH_AdrpAddLdr = 0x3u, ///< Adrp _v@PAGE -> Add _v@PAGEOFF -> Ldr.
+ MCLOH_AdrpLdrGotLdr = 0x4u, ///< Adrp _v@GOTPAGE -> Ldr _v@GOTPAGEOFF -> Ldr.
+ MCLOH_AdrpAddStr = 0x5u, ///< Adrp _v@PAGE -> Add _v@PAGEOFF -> Str.
+ MCLOH_AdrpLdrGotStr = 0x6u, ///< Adrp _v@GOTPAGE -> Ldr _v@GOTPAGEOFF -> Str.
+ MCLOH_AdrpAdd = 0x7u, ///< Adrp _v@PAGE -> Add _v@PAGEOFF.
+ MCLOH_AdrpLdrGot = 0x8u ///< Adrp _v@GOTPAGE -> Ldr _v@GOTPAGEOFF.
+};
+
+static inline StringRef MCLOHDirectiveName() {
+ return StringRef(".loh");
+}
+
+static inline bool isValidMCLOHType(MCLOHType Kind) {
+ return Kind >= MCLOH_AdrpAdrp && Kind <= MCLOH_AdrpLdrGot;
+}
+
+static inline int MCLOHNameToId(StringRef Name) {
+#define MCLOHCaseNameToId(Name) .Case(#Name, MCLOH_ ## Name)
+ return StringSwitch<int>(Name)
+ MCLOHCaseNameToId(AdrpAdrp)
+ MCLOHCaseNameToId(AdrpLdr)
+ MCLOHCaseNameToId(AdrpAddLdr)
+ MCLOHCaseNameToId(AdrpLdrGotLdr)
+ MCLOHCaseNameToId(AdrpAddStr)
+ MCLOHCaseNameToId(AdrpLdrGotStr)
+ MCLOHCaseNameToId(AdrpAdd)
+ MCLOHCaseNameToId(AdrpLdrGot)
+ .Default(-1);
+}
+
+static inline StringRef MCLOHIdToName(MCLOHType Kind) {
+#define MCLOHCaseIdToName(Name) case MCLOH_ ## Name: return StringRef(#Name);
+ switch (Kind) {
+ MCLOHCaseIdToName(AdrpAdrp);
+ MCLOHCaseIdToName(AdrpLdr);
+ MCLOHCaseIdToName(AdrpAddLdr);
+ MCLOHCaseIdToName(AdrpLdrGotLdr);
+ MCLOHCaseIdToName(AdrpAddStr);
+ MCLOHCaseIdToName(AdrpLdrGotStr);
+ MCLOHCaseIdToName(AdrpAdd);
+ MCLOHCaseIdToName(AdrpLdrGot);
+ }
+ return StringRef();
+}
+
+static inline int MCLOHIdToNbArgs(MCLOHType Kind) {
+ switch (Kind) {
+ // LOH with two arguments
+ case MCLOH_AdrpAdrp:
+ case MCLOH_AdrpLdr:
+ case MCLOH_AdrpAdd:
+ case MCLOH_AdrpLdrGot:
+ return 2;
+ // LOH with three arguments
+ case MCLOH_AdrpAddLdr:
+ case MCLOH_AdrpLdrGotLdr:
+ case MCLOH_AdrpAddStr:
+ case MCLOH_AdrpLdrGotStr:
+ return 3;
+ }
+ return -1;
+}
+
+/// Store Linker Optimization Hint information (LOH).
+template<typename T>
+class LOHDirective {
+private:
+ MCLOHType Kind;
+
+ /// Arguments of this directive. Order matters.
+ SmallVector<T *, 3> Args;
+
+ /// Emit this directive in @p OutStream using the information available
+ /// in the given @p ObjWriter and @p Layout to get the address of the
+ /// arguments within the object file.
+ /// This function is currently specialized for T = MCSymbol.
+ void Emit_impl(raw_ostream &OutStream, const MachObjectWriter &ObjWriter,
+ const MCAsmLayout &Layout) const { }
+
+public:
+ typedef SmallVectorImpl<T *> LOHArgs;
+
+ LOHDirective(MCLOHType Kind, const LOHArgs &Args)
+ : Kind(Kind), Args(Args.begin(), Args.end()) {};
+
+ MCLOHType getKind() const { return Kind; }
+
+ const LOHArgs & getArgs() const { return Args; }
+
+ /// Emit this directive as:
+ /// <kind, numArgs, addr1, ..., addrN>
+ void Emit(MachObjectWriter &ObjWriter, const MCAsmLayout &Layout) const {
+ raw_ostream &OutStream = ObjWriter.getStream();
+ Emit_impl(OutStream, ObjWriter, Layout);
+ }
+
+ /// Get the size in bytes of this directive if emitted in @p ObjWriter with
+ /// the given @p Layout.
+ uint64_t getEmitSize(const MachObjectWriter &ObjWriter,
+ const MCAsmLayout &Layout) const {
+ std::string Buffer;
+ raw_string_ostream OutStream(Buffer);
+ Emit_impl(OutStream, ObjWriter, Layout);
+ return OutStream.tell();
+ }
+};
+
+template<typename T>
+class LOHContainer {
+public:
+ typedef SmallVectorImpl<LOHDirective<T> > LOHDirectives;
+
+private:
+ /// Keep track of the emit size of all the LOHs.
+ mutable uint64_t EmitSize;
+
+ /// Keep track of all LOH directives.
+ SmallVector<LOHDirective<T>, 32> Directives;
+
+ /// Accessor to the directives.
+ LOHDirectives &getDirectives() { return Directives; }
+
+public:
+ LOHContainer() : EmitSize(0) {};
+
+ /// Const accessor to the directives.
+ const LOHDirectives &getDirectives() const {
+ return const_cast<LOHContainer *>(this)->getDirectives();
+ }
+
+ /// Add the directive of the given kind @p Kind with the given arguments
+ /// @p Args to the container.
+ void addDirective(MCLOHType Kind,
+ const typename LOHDirective<T>::LOHArgs &Args) {
+ assert(isValidMCLOHType(Kind) && "Invalid LOH directive type!");
+ getDirectives().push_back(LOHDirective<T>(Kind, Args));
+ }
+
+ /// Get the size of the directives if emitted.
+ uint64_t getEmitSize(const MachObjectWriter &ObjWriter,
+ const MCAsmLayout &Layout) const {
+ if (!EmitSize) {
+ for (typename LOHDirectives::const_iterator It = getDirectives().begin(),
+ EndIt = getDirectives().end(); It != EndIt; ++It)
+ EmitSize += It->getEmitSize(ObjWriter, Layout);
+ }
+ return EmitSize;
+ }
+
+ /// Emit all Linker Optimization Hint in one big table.
+ /// Each line of the table is emitted by LOHDirective::Emit.
+ void Emit(MachObjectWriter &ObjWriter, const MCAsmLayout &Layout) const {
+ for (typename LOHDirectives::const_iterator It = getDirectives().begin(),
+ EndIt = getDirectives().end(); It != EndIt; ++It)
+ It->Emit(ObjWriter, Layout);
+ }
+
+ void reset() {
+ getDirectives().clear();
+ EmitSize = 0;
+ }
+};
+
+// Add types for specialized template using MCSymbol.
+typedef LOHDirective<MCSymbol> MCLOHDirective;
+typedef LOHDirective<MCSymbol>::LOHArgs MCLOHArgs;
+
+typedef LOHContainer<MCLOHDirective>::LOHDirectives MCLOHDirectives;
+
+typedef LOHContainer<MCSymbol> MCLOHContainer;
+
+// Declare the specialization for MCSymbol.
+template<>
+void MCLOHDirective::Emit_impl(raw_ostream &OutStream,
+ const MachObjectWriter &ObjWriter,
+ const MCAsmLayout &Layout) const;
+} // end namespace llvm
+
+#endif
LoadCommandsSize += sizeof(MachO::linkedit_data_command);
}
+ // Add the loh load command size, if used.
+ uint64_t LOHRawSize = Asm.getLOHContainer().getEmitSize(*this, Layout);
+ uint64_t LOHSize = RoundUpToAlignment(LOHRawSize, is64Bit() ? 8 : 4);
+ if (LOHSize) {
+ ++NumLoadCommands;
+ LoadCommandsSize += sizeof(MachO::linkedit_data_command);
+ }
+
// Add the symbol table load command sizes, if used.
unsigned NumSymbols = LocalSymbolData.size() + ExternalSymbolData.size() +
UndefinedSymbolData.size();
DataRegionsSize);
}
+ // Write the loh load command, if used.
+ uint64_t LOHTableEnd = DataInCodeTableEnd + LOHSize;
+ if (LOHSize)
+ WriteLinkeditLoadCommand(MachO::LC_LINKER_OPTIMIZATION_HINT,
+ DataInCodeTableEnd, LOHSize);
+
// Write the symbol table load command, if used.
if (NumSymbols) {
unsigned FirstLocalSymbol = 0;
// If used, the indirect symbols are written after the section data.
if (NumIndirectSymbols)
- IndirectSymbolOffset = DataInCodeTableEnd;
+ IndirectSymbolOffset = LOHTableEnd;
// The symbol table is written after the indirect symbol data.
- uint64_t SymbolTableOffset = DataInCodeTableEnd + IndirectSymbolSize;
+ uint64_t SymbolTableOffset = LOHTableEnd + IndirectSymbolSize;
// The string table is written after symbol table.
uint64_t StringTableOffset =
Write16(Data->Kind);
}
+ // Write out the loh commands, if there is one.
+ if (LOHSize) {
+#ifndef NDEBUG
+ unsigned Start = OS.tell();
+#endif
+ Asm.getLOHContainer().Emit(*this, Layout);
+ // Pad to a multiple of the pointer size.
+ WriteBytes("", OffsetToAlignment(LOHRawSize, is64Bit() ? 8 : 4));
+ assert(OS.tell() - Start == LOHSize);
+ }
+
// Write the symbol table data, if used.
if (NumSymbols) {
// Write the indirect symbol entries.
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