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 #include "llvm/Support/MSP430Attributes.h"
21 
22 using namespace llvm;
23 using namespace llvm::MSP430Attrs;
24 
25 namespace llvm {
26 
27 class MSP430TargetELFStreamer : public MCTargetStreamer {
28 public:
29   MCELFStreamer &getStreamer();
30   MSP430TargetELFStreamer(MCStreamer &S, const MCSubtargetInfo &STI);
31 };
32 
33 // This part is for ELF object output.
34 MSP430TargetELFStreamer::MSP430TargetELFStreamer(MCStreamer &S,
35                                                  const MCSubtargetInfo &STI)
36     : MCTargetStreamer(S) {
37   MCAssembler &MCA = getStreamer().getAssembler();
38   unsigned EFlags = MCA.getELFHeaderEFlags();
39   MCA.setELFHeaderEFlags(EFlags);
40 
41   // Emit build attributes section according to
42   // MSP430 EABI (slaa534.pdf, part 13).
43   MCSection *AttributeSection = getStreamer().getContext().getELFSection(
44       ".MSP430.attributes", ELF::SHT_MSP430_ATTRIBUTES, 0);
45   Streamer.SwitchSection(AttributeSection);
46 
47   // Format version.
48   Streamer.emitInt8(0x41);
49   // Subsection length.
50   Streamer.emitInt32(22);
51   // Vendor name string, zero-terminated.
52   Streamer.emitBytes("mspabi");
53   Streamer.emitInt8(0);
54 
55   // Attribute vector scope tag. 1 stands for the entire file.
56   Streamer.emitInt8(1);
57   // Attribute vector length.
58   Streamer.emitInt32(11);
59 
60   Streamer.emitInt8(TagISA);
61   Streamer.emitInt8(STI.hasFeature(MSP430::FeatureX) ? ISAMSP430X : ISAMSP430);
62   Streamer.emitInt8(TagCodeModel);
63   Streamer.emitInt8(CMSmall);
64   Streamer.emitInt8(TagDataModel);
65   Streamer.emitInt8(DMSmall);
66   // Don't emit TagEnumSize, for full GCC compatibility.
67 }
68 
69 MCELFStreamer &MSP430TargetELFStreamer::getStreamer() {
70   return static_cast<MCELFStreamer &>(Streamer);
71 }
72 
73 MCTargetStreamer *
74 createMSP430ObjectTargetStreamer(MCStreamer &S, const MCSubtargetInfo &STI) {
75   const Triple &TT = STI.getTargetTriple();
76   if (TT.isOSBinFormatELF())
77     return new MSP430TargetELFStreamer(S, STI);
78   return nullptr;
79 }
80 
81 } // namespace llvm
82