C++ (Cpp) MCSymbolELF::setSize示例

示例#1

void AMDGPUTargetELFStreamer::EmitAmdhsaKernelDescriptor(
    const MCSubtargetInfo &STI, StringRef KernelName,
    const amdhsa::kernel_descriptor_t &KernelDescriptor, uint64_t NextVGPR,
    uint64_t NextSGPR, bool ReserveVCC, bool ReserveFlatScr,
    bool ReserveXNACK) {
  auto &Streamer = getStreamer();
  auto &Context = Streamer.getContext();

  MCSymbolELF *KernelCodeSymbol = cast<MCSymbolELF>(
      Context.getOrCreateSymbol(Twine(KernelName)));
  MCSymbolELF *KernelDescriptorSymbol = cast<MCSymbolELF>(
      Context.getOrCreateSymbol(Twine(KernelName) + Twine(".kd")));

  // Copy kernel descriptor symbol's binding, other and visibility from the
  // kernel code symbol.
  KernelDescriptorSymbol->setBinding(KernelCodeSymbol->getBinding());
  KernelDescriptorSymbol->setOther(KernelCodeSymbol->getOther());
  KernelDescriptorSymbol->setVisibility(KernelCodeSymbol->getVisibility());
  // Kernel descriptor symbol's type and size are fixed.
  KernelDescriptorSymbol->setType(ELF::STT_OBJECT);
  KernelDescriptorSymbol->setSize(
      MCConstantExpr::create(sizeof(KernelDescriptor), Context));

  // The visibility of the kernel code symbol must be protected or less to allow
  // static relocations from the kernel descriptor to be used.
  if (KernelCodeSymbol->getVisibility() == ELF::STV_DEFAULT)
    KernelCodeSymbol->setVisibility(ELF::STV_PROTECTED);

  Streamer.EmitLabel(KernelDescriptorSymbol);
  Streamer.EmitBytes(StringRef(
      (const char*)&(KernelDescriptor),
      offsetof(amdhsa::kernel_descriptor_t, kernel_code_entry_byte_offset)));
  // FIXME: Remove the use of VK_AMDGPU_REL64 in the expression below. The
  // expression being created is:
  //   (start of kernel code) - (start of kernel descriptor)
  // It implies R_AMDGPU_REL64, but ends up being R_AMDGPU_ABS64.
  Streamer.EmitValue(MCBinaryExpr::createSub(
      MCSymbolRefExpr::create(
          KernelCodeSymbol, MCSymbolRefExpr::VK_AMDGPU_REL64, Context),
      MCSymbolRefExpr::create(
          KernelDescriptorSymbol, MCSymbolRefExpr::VK_None, Context),
      Context),
      sizeof(KernelDescriptor.kernel_code_entry_byte_offset));
  Streamer.EmitBytes(StringRef(
      (const char*)&(KernelDescriptor) +
          offsetof(amdhsa::kernel_descriptor_t, kernel_code_entry_byte_offset) +
          sizeof(KernelDescriptor.kernel_code_entry_byte_offset),
      sizeof(KernelDescriptor) -
          offsetof(amdhsa::kernel_descriptor_t, kernel_code_entry_byte_offset) -
          sizeof(KernelDescriptor.kernel_code_entry_byte_offset)));
}

示例#2

文件： AMDGPUTargetStreamer.cpp 项目： Lucretia/llvm

void AMDGPUTargetELFStreamer::EmitAmdhsaKernelDescriptor(
    const MCSubtargetInfo &STI, StringRef KernelName,
    const amdhsa::kernel_descriptor_t &KernelDescriptor, uint64_t NextVGPR,
    uint64_t NextSGPR, bool ReserveVCC, bool ReserveFlatScr,
    bool ReserveXNACK) {
  auto &Streamer = getStreamer();
  auto &Context = Streamer.getContext();

  MCSymbolELF *KernelDescriptorSymbol = cast<MCSymbolELF>(
      Context.getOrCreateSymbol(Twine(KernelName) + Twine(".kd")));
  KernelDescriptorSymbol->setBinding(ELF::STB_GLOBAL);
  KernelDescriptorSymbol->setType(ELF::STT_OBJECT);
  KernelDescriptorSymbol->setSize(
      MCConstantExpr::create(sizeof(KernelDescriptor), Context));

  MCSymbolELF *KernelCodeSymbol = cast<MCSymbolELF>(
      Context.getOrCreateSymbol(Twine(KernelName)));
  KernelCodeSymbol->setBinding(ELF::STB_LOCAL);

  Streamer.EmitLabel(KernelDescriptorSymbol);
  Streamer.EmitBytes(StringRef(
      (const char*)&(KernelDescriptor),
      offsetof(amdhsa::kernel_descriptor_t, kernel_code_entry_byte_offset)));
  // FIXME: Remove the use of VK_AMDGPU_REL64 in the expression below. The
  // expression being created is:
  //   (start of kernel code) - (start of kernel descriptor)
  // It implies R_AMDGPU_REL64, but ends up being R_AMDGPU_ABS64.
  Streamer.EmitValue(MCBinaryExpr::createSub(
      MCSymbolRefExpr::create(
          KernelCodeSymbol, MCSymbolRefExpr::VK_AMDGPU_REL64, Context),
      MCSymbolRefExpr::create(
          KernelDescriptorSymbol, MCSymbolRefExpr::VK_None, Context),
      Context),
      sizeof(KernelDescriptor.kernel_code_entry_byte_offset));
  Streamer.EmitBytes(StringRef(
      (const char*)&(KernelDescriptor) +
          offsetof(amdhsa::kernel_descriptor_t, kernel_code_entry_byte_offset) +
          sizeof(KernelDescriptor.kernel_code_entry_byte_offset),
      sizeof(KernelDescriptor) -
          offsetof(amdhsa::kernel_descriptor_t, kernel_code_entry_byte_offset) -
          sizeof(KernelDescriptor.kernel_code_entry_byte_offset)));
}