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/MCContext.h"
  16 #include "llvm/MC/MCELFStreamer.h"
  17 #include "llvm/MC/MCSectionELF.h"
  18 #include "llvm/MC/MCStreamer.h"
  19 #include "llvm/MC/MCSubtargetInfo.h"
  20
  21 using namespace llvm;
  22
  23 namespace llvm {
  24
  25 class MSP430TargetELFStreamer : public MCTargetStreamer {
  26 public:
  27   MCELFStreamer &getStreamer();
  28   MSP430TargetELFStreamer(MCStreamer &S, const MCSubtargetInfo &STI);
  29 };
  30
  31 // This part is for ELF object output.
  32 MSP430TargetELFStreamer::MSP430TargetELFStreamer(MCStreamer &S,
  33                                                  const MCSubtargetInfo &STI)
  34     : MCTargetStreamer(S) {
  35   MCAssembler &MCA = getStreamer().getAssembler();
  36   unsigned EFlags = MCA.getELFHeaderEFlags();
  37   MCA.setELFHeaderEFlags(EFlags);
  38
  39   // Emit build attributes section according to
  40   // MSP430 EABI (slaa534.pdf, part 13).
  41   MCSection *AttributeSection = getStreamer().getContext().getELFSection(
  42       ".MSP430.attributes", ELF::SHT_MSP430_ATTRIBUTES, 0);
  43   Streamer.SwitchSection(AttributeSection);
  44
  45   // Format version.
  46   Streamer.EmitIntValue(0x41, 1);
  47   // Subsection length.
  48   Streamer.EmitIntValue(22, 4);
  49   // Vendor name string, zero-terminated.
  50   Streamer.EmitBytes("mspabi");
  51   Streamer.EmitIntValue(0, 1);
  52
  53   // Attribute vector scope tag. 1 stands for the entire file.
  54   Streamer.EmitIntValue(1, 1);
  55   // Attribute vector length.
  56   Streamer.EmitIntValue(11, 4);
  57   // OFBA_MSPABI_Tag_ISA(4) = 1, MSP430
  58   Streamer.EmitIntValue(4, 1);
  59   Streamer.EmitIntValue(1, 1);
  60   // OFBA_MSPABI_Tag_Code_Model(6) = 1, Small
  61   Streamer.EmitIntValue(6, 1);
  62   Streamer.EmitIntValue(1, 1);
  63   // OFBA_MSPABI_Tag_Data_Model(8) = 1, Small
  64   Streamer.EmitIntValue(8, 1);
  65   Streamer.EmitIntValue(1, 1);
  66 }
  67
  68 MCELFStreamer &MSP430TargetELFStreamer::getStreamer() {
  69   return static_cast<MCELFStreamer &>(Streamer);
  70 }
  71
  72 MCTargetStreamer *
  73 createMSP430ObjectTargetStreamer(MCStreamer &S, const MCSubtargetInfo &STI) {
  74   const Triple &TT = STI.getTargetTriple();
  75   if (TT.isOSBinFormatELF())
  76     return new MSP430TargetELFStreamer(S, STI);
  77   return nullptr;
  78 }
  79
  80 } // namespace llvm