llvm/lib/Target/MSP430/MCTargetDesc/MSP430ELFStreamer.cpp

   1 //===-- MSP430ELFStreamer.cpp - MSP430 ELF Target Streamer Methods --------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file provides MSP430 specific target streamer methods.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "MSP430MCTargetDesc.h"
  14 #include "llvm/BinaryFormat/ELF.h"
  15 #include "llvm/MC/MCAssembler.h"
  16 #include "llvm/MC/MCContext.h"
  17 #include "llvm/MC/MCELFStreamer.h"
  18 #include "llvm/MC/MCSectionELF.h"
  19 #include "llvm/MC/MCStreamer.h"
  20 #include "llvm/MC/MCSubtargetInfo.h"
  21 #include "llvm/Support/MSP430Attributes.h"
  22
  23 using namespace llvm;
  24 using namespace llvm::MSP430Attrs;
  25
  26 namespace llvm {
  27
  28 class MSP430TargetELFStreamer : public MCTargetStreamer {
  29 public:
  30   MCELFStreamer &getStreamer();
  31   MSP430TargetELFStreamer(MCStreamer &S, const MCSubtargetInfo &STI);
  32 };
  33
  34 // This part is for ELF object output.
  35 MSP430TargetELFStreamer::MSP430TargetELFStreamer(MCStreamer &S,
  36                                                  const MCSubtargetInfo &STI)
  37     : MCTargetStreamer(S) {
  38   MCAssembler &MCA = getStreamer().getAssembler();
  39   unsigned EFlags = MCA.getELFHeaderEFlags();
  40   MCA.setELFHeaderEFlags(EFlags);
  41
  42   // Emit build attributes section according to
  43   // MSP430 EABI (slaa534.pdf, part 13).
  44   MCSection *AttributeSection = getStreamer().getContext().getELFSection(
  45       ".MSP430.attributes", ELF::SHT_MSP430_ATTRIBUTES, 0);
  46   Streamer.switchSection(AttributeSection);
  47
  48   // Format version.
  49   Streamer.emitInt8(0x41);
  50   // Subsection length.
  51   Streamer.emitInt32(22);
  52   // Vendor name string, zero-terminated.
  53   Streamer.emitBytes("mspabi");
  54   Streamer.emitInt8(0);
  55
  56   // Attribute vector scope tag. 1 stands for the entire file.
  57   Streamer.emitInt8(1);
  58   // Attribute vector length.
  59   Streamer.emitInt32(11);
  60
  61   Streamer.emitInt8(TagISA);
  62   Streamer.emitInt8(STI.hasFeature(MSP430::FeatureX) ? ISAMSP430X : ISAMSP430);
  63   Streamer.emitInt8(TagCodeModel);
  64   Streamer.emitInt8(CMSmall);
  65   Streamer.emitInt8(TagDataModel);
  66   Streamer.emitInt8(DMSmall);
  67   // Don't emit TagEnumSize, for full GCC compatibility.
  68 }
  69
  70 MCELFStreamer &MSP430TargetELFStreamer::getStreamer() {
  71   return static_cast<MCELFStreamer &>(Streamer);
  72 }
  73
  74 MCTargetStreamer *
  75 createMSP430ObjectTargetStreamer(MCStreamer &S, const MCSubtargetInfo &STI) {
  76   const Triple &TT = STI.getTargetTriple();
  77   if (TT.isOSBinFormatELF())
  78     return new MSP430TargetELFStreamer(S, STI);
  79   return nullptr;
  80 }
  81
  82 } // namespace llvm