llvm/lib/Target/AVR/AVRTargetObjectFile.cpp

   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
  21 namespace llvm {
  22 void 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
  38 MCSection *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