reference, declarationdefinition
definition → references, declarations, derived classes, virtual overrides
reference to multiple definitions → definitions
unreferenced
    1
    2
    3
    4
    5
    6
    7
    8
    9
   10
   11
   12
   13
   14
   15
   16
   17
   18
   19
   20
   21
   22
   23
   24
   25
   26
   27
   28
   29
   30
   31
   32
   33
   34
   35
   36
   37
   38
   39
   40
   41
   42
   43
   44
   45
   46
   47
   48
   49
   50
   51
   52
   53
   54
   55
   56
   57
   58
   59
   60
   61
   62
   63
   64
   65
   66
   67
   68
   69
   70
   71
   72
   73
   74
   75
   76
   77
   78
   79
   80
   81
   82
   83
   84
   85
   86
   87
   88
   89
   90
   91
   92
   93
   94
   95
   96
   97
   98
   99
  100
  101
  102
  103
  104
  105
  106
  107
  108
  109
  110
  111
  112
  113
  114
  115
  116
  117
  118
  119
  120
  121
  122
  123
  124
  125
  126
  127
  128
  129
  130
  131
  132
  133
  134
  135
  136
  137
  138
  139
  140
  141
  142
  143
  144
  145
  146
  147
  148
  149
  150
  151
  152
  153
  154
  155
  156
  157
  158
  159
  160
  161
  162
  163
  164
  165
  166
  167
  168
  169
  170
  171
  172
  173
  174
  175
  176
  177
  178
  179
  180
  181
  182
  183
  184
  185
  186
  187
  188
  189
  190
  191
//===-- RenderScriptExpressionOpts.cpp --------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#include <string>

#include "llvm/ADT/None.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/IR/Instruction.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/LegacyPassManager.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"

#include "clang/Basic/TargetOptions.h"

#include "lldb/Target/Process.h"
#include "lldb/Target/Target.h"
#include "lldb/Utility/Log.h"

#include "RenderScriptExpressionOpts.h"
#include "RenderScriptRuntime.h"
#include "RenderScriptx86ABIFixups.h"

using namespace lldb_private;
using namespace lldb_renderscript;

// [``slang``](https://android.googlesource.com/platform/frameworks/compile/slang),
// the compiler frontend for RenderScript embeds an ARM specific triple in IR
// that is shipped in the app, after generating IR that has some assumptions
// that an ARM device is the target. As the IR is then compiled on a device of
// unknown (at time the IR was generated at least) architecture, when calling
// RenderScript API function as part of debugger expressions, we have to
// perform a fixup pass that removes those assumptions right before the module
// is sent to be generated by the llvm backend.

namespace {
bool registerRSDefaultTargetOpts(clang::TargetOptions &proto,
                                 const llvm::Triple::ArchType &arch) {
  switch (arch) {
  case llvm::Triple::ArchType::x86:
    proto.Triple = "i686--linux-android";
    proto.CPU = "atom";
    proto.Features.push_back("+long64");
    // Fallthrough for common x86 family features
    LLVM_FALLTHROUGH;
  case llvm::Triple::ArchType::x86_64:
    proto.Features.push_back("+mmx");
    proto.Features.push_back("+sse");
    proto.Features.push_back("+sse2");
    proto.Features.push_back("+sse3");
    proto.Features.push_back("+ssse3");
    proto.Features.push_back("+sse4.1");
    proto.Features.push_back("+sse4.2");
    break;
  case llvm::Triple::ArchType::mipsel:
    // pretend this is `arm' for the front-end
    proto.Triple = "armv7-none-linux-android";
    proto.CPU = "";
    proto.Features.push_back("+long64");
    break;
  case llvm::Triple::ArchType::mips64el:
    // pretend this is `aarch64' for the front-end
    proto.Triple = "aarch64-none-linux-android";
    proto.CPU = "";
    break;
  default:
    return false;
  }
  return true;
}
} // end anonymous namespace

bool RenderScriptRuntimeModulePass::runOnModule(llvm::Module &module) {
  bool changed_module = false;
  Log *log(
      GetLogIfAllCategoriesSet(LIBLLDB_LOG_LANGUAGE | LIBLLDB_LOG_EXPRESSIONS));

  std::string err;
  llvm::StringRef real_triple =
      m_process_ptr->GetTarget().GetArchitecture().GetTriple().getTriple();
  const llvm::Target *target_info =
      llvm::TargetRegistry::lookupTarget(real_triple, err);
  if (!target_info) {
    if (log)
      log->Warning("couldn't determine real target architecture: '%s'",
                   err.c_str());
    return false;
  }

  llvm::Optional<llvm::Reloc::Model> reloc_model = llvm::None;
  assert(m_process_ptr && "no available lldb process");
  switch (m_process_ptr->GetTarget().GetArchitecture().GetMachine()) {
  case llvm::Triple::ArchType::x86:
    changed_module |= fixupX86FunctionCalls(module);
    // For some reason this triple gets totally missed by the backend, and must
    // be set manually. There a reference in bcc/Main.cpp about auto feature-
    // detection being removed from LLVM3.5, but I can't see that discussion
    // anywhere public.
    real_triple = "i686--linux-android";
    break;
  case llvm::Triple::ArchType::x86_64:
    changed_module |= fixupX86_64FunctionCalls(module);
    break;
  case llvm::Triple::ArchType::mipsel:
  case llvm::Triple::ArchType::mips64el:
    // No actual IR fixup pass is needed on MIPS, but the datalayout and
    // targetmachine do need to be explicitly set.

    // bcc explicitly compiles MIPS code to use the static relocation model due
    // to an issue with relocations in mclinker. see
    // libbcc/support/CompilerConfig.cpp for details
    reloc_model = llvm::Reloc::Static;
    changed_module = true;
    break;
  case llvm::Triple::ArchType::arm:
  case llvm::Triple::ArchType::aarch64:
    // ARM subtargets need no fixup passes as they are the initial target as
    // generated by the
    // slang compiler frontend.
    break;
  default:
    if (log)
      log->Warning("Ignoring unknown renderscript target");
    return false;
  }

  if (changed_module) {
    llvm::TargetOptions options;
    llvm::TargetMachine *target_machine = target_info->createTargetMachine(
        real_triple, "", "", options, reloc_model);
    assert(target_machine &&
           "failed to identify RenderScriptRuntime target machine");
    // We've been using a triple and datalayout of some ARM variant all along,
    // so we need to let the backend know that this is no longer the case.
    if (log) {
      LLDB_LOGF(log, "%s - Changing RS target triple to '%s'", __FUNCTION__,
                real_triple.str().c_str());
      LLDB_LOGF(
          log, "%s - Changing RS datalayout to '%s'", __FUNCTION__,
          target_machine->createDataLayout().getStringRepresentation().c_str());
    }
    module.setTargetTriple(real_triple);
    module.setDataLayout(target_machine->createDataLayout());
  }
  return changed_module;
}

char RenderScriptRuntimeModulePass::ID = 0;

namespace lldb_private {

bool RenderScriptRuntime::GetOverrideExprOptions(clang::TargetOptions &proto) {
  auto *process = GetProcess();
  assert(process);
  return registerRSDefaultTargetOpts(
      proto, process->GetTarget().GetArchitecture().GetMachine());
}

bool RenderScriptRuntime::GetIRPasses(LLVMUserExpression::IRPasses &passes) {
  if (!m_ir_passes)
    m_ir_passes = new RSIRPasses(GetProcess());
  assert(m_ir_passes);

  passes.EarlyPasses = m_ir_passes->EarlyPasses;
  passes.LatePasses = m_ir_passes->LatePasses;

  return true;
}

namespace lldb_renderscript {

RSIRPasses::RSIRPasses(Process *process) {
  IRPasses();
  assert(process);

  EarlyPasses = std::make_shared<llvm::legacy::PassManager>();
  assert(EarlyPasses);
  EarlyPasses->add(new RenderScriptRuntimeModulePass(process));
}

RSIRPasses::~RSIRPasses() {}

} // namespace lldb_renderscript
} // namespace lldb_private