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
83