src/llvm/lib/MC/MCLinkerOptimizationHint.cpp

   1 //===-- llvm/MC/MCLinkerOptimizationHint.cpp ----- LOH handling -*- C++ -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "llvm/MC/MCLinkerOptimizationHint.h"
  11 #include "llvm/MC/MCAsmLayout.h"
  12 #include "llvm/MC/MCStreamer.h"
  13 #include "llvm/Support/LEB128.h"
  14
  15 using namespace llvm;
  16
  17 // Each LOH is composed by, in this order (each field is encoded using ULEB128):
  18 // - Its kind.
  19 // - Its number of arguments (let say N).
  20 // - Its arg1.
  21 // - ...
  22 // - Its argN.
  23 // <arg1> to <argN> are absolute addresses in the object file, i.e.,
  24 // relative addresses from the beginning of the object file.
  25 void MCLOHDirective::Emit_impl(raw_ostream &OutStream,
  26                                const MachObjectWriter &ObjWriter,
  27                                const MCAsmLayout &Layout) const {
  28   const MCAssembler &Asm = Layout.getAssembler();
  29   encodeULEB128(Kind, OutStream);
  30   encodeULEB128(Args.size(), OutStream);
  31   for (LOHArgs::const_iterator It = Args.begin(), EndIt = Args.end();
  32        It != EndIt; ++It)
  33     encodeULEB128(ObjWriter.getSymbolAddress(&Asm.getSymbolData(**It), Layout),
  34                   OutStream);
  35 }