blob: a234dcd0f24ea28ff699a9ddc7501228f77646eb [file] [log] [blame]
// Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
#include "vm/globals.h"
#if defined(TARGET_ARCH_MIPS)
#include "vm/cpu.h"
#include "vm/debugger.h"
#include "vm/instructions.h"
#include "vm/stub_code.h"
namespace dart {
// TODO(hausner): Handle captured variables.
RawInstance* ActivationFrame::GetLocalVarValue(intptr_t slot_index) {
uword var_address = fp() + slot_index * kWordSize;
return reinterpret_cast<RawInstance*>(
*reinterpret_cast<uword*>(var_address));
}
RawInstance* ActivationFrame::GetInstanceCallReceiver(
intptr_t num_actual_args) {
ASSERT(num_actual_args > 0); // At minimum we have a receiver on the stack.
// Stack pointer points to last argument that was pushed on the stack.
uword receiver_addr = sp() + ((num_actual_args - 1) * kWordSize);
return reinterpret_cast<RawInstance*>(
*reinterpret_cast<uword*>(receiver_addr));
}
void CodeBreakpoint::PatchFunctionReturn() {
Instr* instr1 = Instr::At(pc_ - 6 * Instr::kInstrSize);
Instr* instr2 = Instr::At(pc_ - 5 * Instr::kInstrSize);
Instr* instr3 = Instr::At(pc_ - 4 * Instr::kInstrSize);
Instr* instr4 = Instr::At(pc_ - 3 * Instr::kInstrSize);
Instr* instr5 = Instr::At(pc_ - 2 * Instr::kInstrSize);
Instr* instr6 = Instr::At(pc_ - 1 * Instr::kInstrSize);
#if defined(DEBUG)
instr1->AssertIsImmInstr(LW, SP, RA, 2 * kWordSize);
instr2->AssertIsImmInstr(LW, SP, FP, 1 * kWordSize);
instr3->AssertIsImmInstr(LW, SP, PP, 0 * kWordSize);
instr4->AssertIsImmInstr(ADDIU, SP, SP, 4 * kWordSize);
instr5->AssertIsSpecialInstr(JR, RA, ZR, ZR);
ASSERT(instr6->InstructionBits() == Instr::kNopInstruction);
#endif // defined(DEBUG)
// Smash code with call instruction and target address.
uword stub_addr = StubCode::BreakpointReturnEntryPoint();
uint16_t target_lo = stub_addr & 0xffff;
uint16_t target_hi = stub_addr >> 16;
// Unlike other architectures, the sequence we are patching in is shorter
// than the sequence we are replacing. We pad at the top with nops so that
// the end of the new sequence is lined up with the code descriptor.
instr1->SetInstructionBits(Instr::kNopInstruction);
instr2->SetInstructionBits(Instr::kNopInstruction);
instr3->SetImmInstrBits(LUI, ZR, TMP1, target_hi);
instr4->SetImmInstrBits(ORI, TMP1, TMP1, target_lo);
instr5->SetSpecialInstrBits(JALR, TMP1, ZR, RA);
instr6->SetInstructionBits(Instr::kNopInstruction);
CPU::FlushICache(pc_ - 6 * Instr::kInstrSize, 6 * Instr::kInstrSize);
}
void CodeBreakpoint::RestoreFunctionReturn() {
Instr* instr1 = Instr::At(pc_ - 6 * Instr::kInstrSize);
Instr* instr2 = Instr::At(pc_ - 5 * Instr::kInstrSize);
Instr* instr3 = Instr::At(pc_ - 4 * Instr::kInstrSize);
Instr* instr4 = Instr::At(pc_ - 3 * Instr::kInstrSize);
Instr* instr5 = Instr::At(pc_ - 2 * Instr::kInstrSize);
Instr* instr6 = Instr::At(pc_ - 1 * Instr::kInstrSize);
ASSERT(instr3->OpcodeField() == LUI && instr3->RtField() == TMP1);
instr1->SetImmInstrBits(LW, SP, RA, 2 * kWordSize);
instr2->SetImmInstrBits(LW, SP, FP, 1 * kWordSize);
instr3->SetImmInstrBits(LW, SP, PP, 0 * kWordSize);
instr4->SetImmInstrBits(ADDIU, SP, SP, 4 * kWordSize);
instr5->SetSpecialInstrBits(JR, RA, ZR, ZR);
instr6->SetInstructionBits(Instr::kNopInstruction);
CPU::FlushICache(pc_ - 6 * Instr::kInstrSize, 6 * Instr::kInstrSize);
}
} // namespace dart
#endif // defined TARGET_ARCH_MIPS