189 lines
6.7 KiB
C++
189 lines
6.7 KiB
C++
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// Copyright 2006-2008 Google Inc. All Rights Reserved.
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions are
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// met:
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//
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// * Redistributions of source code must retain the above copyright
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// notice, this list of conditions and the following disclaimer.
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// * Redistributions in binary form must reproduce the above
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// copyright notice, this list of conditions and the following
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// disclaimer in the documentation and/or other materials provided
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// with the distribution.
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// * Neither the name of Google Inc. nor the names of its
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// contributors may be used to endorse or promote products derived
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// from this software without specific prior written permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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#include "v8.h"
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#include "frames-inl.h"
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#include "assembler-arm-inl.h"
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namespace v8 { namespace internal {
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StackFrame::Type StackFrame::ComputeType(State* state) {
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ASSERT(state->fp != NULL);
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if (state->pp == NULL) {
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if (Memory::Address_at(state->fp +
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EntryFrameConstants::kConstructMarkOffset) != 0) {
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return ENTRY_CONSTRUCT;
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} else {
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return ENTRY;
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}
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} else if (StandardFrame::IsArgumentsAdaptorFrame(state->fp)) {
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return ARGUMENTS_ADAPTOR;
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} else if (
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Memory::Object_at(state->fp +
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StandardFrameConstants::kFunctionOffset)->IsSmi()) {
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return INTERNAL;
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} else {
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return JAVA_SCRIPT;
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}
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}
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StackFrame::Type ExitFrame::GetStateForFramePointer(Address fp, State* state) {
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if (fp == 0) return NONE;
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// Compute frame type and stack pointer.
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Address sp = fp + ExitFrameConstants::kSPDisplacement;
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Type type;
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if (Memory::Address_at(fp + ExitFrameConstants::kDebugMarkOffset) != 0) {
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type = EXIT_DEBUG;
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sp -= kNumJSCallerSaved * kPointerSize;
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} else {
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type = EXIT;
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}
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// Fill in the state.
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state->sp = sp;
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state->fp = fp;
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state->pp = fp + ExitFrameConstants::kPPDisplacement;
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state->pc_address = reinterpret_cast<Address*>(sp - 1 * kPointerSize);
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return type;
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}
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void ExitFrame::Iterate(ObjectVisitor* v) const {
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// Traverse pointers in the callee-saved registers.
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const int offset = ExitFrameConstants::kSavedRegistersOffset;
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Object** base = &Memory::Object_at(fp() + offset);
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Object** limit = base + kNumJSCalleeSaved;
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v->VisitPointers(base, limit);
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}
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void ExitFrame::RestoreCalleeSavedRegisters(Object* buffer[]) const {
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// The callee-saved registers in an exit frame are pointed to by the
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// frame pointer. See the implementations of C entry runtime stubs.
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const int offset = ExitFrameConstants::kSavedRegistersOffset;
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memcpy(buffer, fp() + offset, kNumJSCalleeSaved * kPointerSize);
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}
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int JavaScriptFrame::GetProvidedParametersCount() const {
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const int offset = JavaScriptFrameConstants::kArgsLengthOffset;
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int result = Memory::int_at(fp() + offset);
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// We never remove extra parameters provided on the stack; we only
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// fill in undefined values for parameters not provided.
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ASSERT(0 <= result && result <= ComputeParametersCount());
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return result;
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}
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Address JavaScriptFrame::GetCallerStackPointer() const {
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return state_.pp;
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}
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Address ArgumentsAdaptorFrame::GetCallerStackPointer() const {
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// Argument adaptor frames aren't used on ARM (yet).
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UNIMPLEMENTED();
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return 0;
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}
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Address InternalFrame::GetCallerStackPointer() const {
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return state_.pp;
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}
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RegList JavaScriptFrame::FindCalleeSavedRegisters() const {
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const unsigned kRegListTag = 1; // pc values have bit 0 cleared (no thumb)
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const unsigned kRegListTagSize = 1;
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const unsigned kRegListTagMask = (1 << kRegListTagSize) - 1;
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// The prologue pc (or the cached register list) is available as a
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// slot in the fixed part of the stack frame.
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const int offset = +4 * kPointerSize;
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// Once the register list has been calculated for a frame, it is
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// cached in the prologue pc stack slot. Check the cache before
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// doing the more expensive instruction decoding.
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uint32_t cache = Memory::int_at(fp() + offset);
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if ((cache & kRegListTagMask) == kRegListTag) {
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return static_cast<RegList>(cache >> kRegListTagSize);
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}
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// If we can't find the register list in the instruction stream, we
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// assume it's the empty list. [NOTE: Is this really a smart thing
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// to do? Don't all JavaScript frames have the instruction?]
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RegList result = 0;
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// Compute the address of the stm (store multiple) instruction.
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Address stm_address = AddressFrom<Address>(cache - PcStoreOffset());
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ASSERT((Memory::int32_at(stm_address) & 0xffffcc00) == 0xe92dcc00);
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// Fetch the instruction preceeding the stm - if it is also a stm
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// instruction we read the register list from there.
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uint32_t instruction = Memory::int32_at(stm_address - 4);
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if ((instruction & 0xfffffc00) == 0xe92d0000) {
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// The register list shouldn't be empty and must consist only of JS
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// callee-saved registers.
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result = instruction & 0xffff;
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ASSERT(result != 0 && (result & ~kJSCalleeSaved) == 0);
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}
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// Cache the result in the prologue pc stack slot before returning
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// it. This way future access to the register list is a bit faster.
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Memory::int_at(fp() + offset) = (result << kRegListTagSize) | kRegListTag;
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return result;
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}
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void JavaScriptFrame::RestoreCalleeSavedRegisters(Object* buffer[]) const {
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// The callee-saved registers in java script frames are in the fixed
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// part of the frame below the frame pointer.
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const int n = NumRegs(FindCalleeSavedRegisters());
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const int offset = 5 * kPointerSize;
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memcpy(buffer, fp() + offset, n * kPointerSize);
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}
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Code* JavaScriptFrame::FindCode() const {
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const int offset = StandardFrameConstants::kCodeOffset;
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Object* code = Memory::Object_at(fp() + offset);
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if (code == NULL) {
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// The code object isn't set; find it and set it.
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code = Heap::FindCodeObject(pc());
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ASSERT(!code->IsFailure());
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Memory::Object_at(fp() + offset) = code;
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}
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ASSERT(code != NULL);
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return Code::cast(code);
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}
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} } // namespace v8::internal
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