1//===-- AVRTargetObjectFile.cpp - AVR Object Files ------------------------===//
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#include "AVRTargetObjectFile.h"
10#include "AVRTargetMachine.h"
11
12#include "llvm/BinaryFormat/ELF.h"
13#include "llvm/IR/DerivedTypes.h"
14#include "llvm/IR/GlobalValue.h"
15#include "llvm/IR/Mangler.h"
16#include "llvm/MC/MCContext.h"
17#include "llvm/MC/MCSectionELF.h"
18
19#include "AVR.h"
20
21namespace llvm {
22void AVRTargetObjectFile::Initialize(MCContext &Ctx, const TargetMachine &TM) {
23  Base::Initialize(Ctx, TM);
24  ProgmemDataSection =
25      Ctx.getELFSection(".progmem.data", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
26  Progmem1DataSection =
27      Ctx.getELFSection(".progmem1.data", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
28  Progmem2DataSection =
29      Ctx.getELFSection(".progmem2.data", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
30  Progmem3DataSection =
31      Ctx.getELFSection(".progmem3.data", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
32  Progmem4DataSection =
33      Ctx.getELFSection(".progmem4.data", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
34  Progmem5DataSection =
35      Ctx.getELFSection(".progmem5.data", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
36}
37
38MCSection *AVRTargetObjectFile::SelectSectionForGlobal(
39    const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
40  // Global values in flash memory are placed in the progmem*.data section
41  // unless they already have a user assigned section.
42  const auto &AVRTM = static_cast<const AVRTargetMachine &>(TM);
43  if (AVR::isProgramMemoryAddress(GO) && !GO->hasSection() &&
44      Kind.isReadOnly()) {
45    // The AVR subtarget should support LPM to access section '.progmem*.data'.
46    if (!AVRTM.getSubtargetImpl()->hasLPM()) {
47      // TODO: Get the global object's location in source file.
48      getContext().reportError(
49          SMLoc(),
50          "Current AVR subtarget does not support accessing program memory");
51      return Base::SelectSectionForGlobal(GO, Kind, TM);
52    }
53    // The AVR subtarget should support ELPM to access section
54    // '.progmem[1|2|3|4|5].data'.
55    if (!AVRTM.getSubtargetImpl()->hasELPM() &&
56        AVR::getAddressSpace(GO) != AVR::ProgramMemory) {
57      // TODO: Get the global object's location in source file.
58      getContext().reportError(SMLoc(),
59                               "Current AVR subtarget does not support "
60                               "accessing extended program memory");
61      return ProgmemDataSection;
62    }
63    switch (AVR::getAddressSpace(GO)) {
64    case AVR::ProgramMemory: // address space 1
65      return ProgmemDataSection;
66    case AVR::ProgramMemory1: // address space 2
67      return Progmem1DataSection;
68    case AVR::ProgramMemory2: // address space 3
69      return Progmem2DataSection;
70    case AVR::ProgramMemory3: // address space 4
71      return Progmem3DataSection;
72    case AVR::ProgramMemory4: // address space 5
73      return Progmem4DataSection;
74    case AVR::ProgramMemory5: // address space 6
75      return Progmem5DataSection;
76    default:
77      llvm_unreachable("unexpected program memory index");
78    }
79  }
80
81  // Otherwise, we work the same way as ELF.
82  return Base::SelectSectionForGlobal(GO, Kind, TM);
83}
84} // end of namespace llvm
85