v8/src/disassembler.cc

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// Copyright 2011 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/disassembler.h"
#include "src/code-stubs.h"
#include "src/codegen.h"
#include "src/debug/debug.h"
#include "src/deoptimizer.h"
#include "src/disasm.h"
#include "src/ic/ic.h"
#include "src/macro-assembler.h"
#include "src/snapshot/serializer-common.h"
#include "src/string-stream.h"
namespace v8 {
namespace internal {
#ifdef ENABLE_DISASSEMBLER
class V8NameConverter: public disasm::NameConverter {
public:
explicit V8NameConverter(Code* code) : code_(code) {}
virtual const char* NameOfAddress(byte* pc) const;
virtual const char* NameInCode(byte* addr) const;
Code* code() const { return code_; }
private:
Code* code_;
EmbeddedVector<char, 128> v8_buffer_;
};
const char* V8NameConverter::NameOfAddress(byte* pc) const {
const char* name =
code_ == NULL ? NULL : code_->GetIsolate()->builtins()->Lookup(pc);
if (name != NULL) {
SNPrintF(v8_buffer_, "%s (%p)", name, static_cast<void*>(pc));
return v8_buffer_.start();
}
if (code_ != NULL) {
int offs = static_cast<int>(pc - code_->instruction_start());
// print as code offset, if it seems reasonable
if (0 <= offs && offs < code_->instruction_size()) {
SNPrintF(v8_buffer_, "%d (%p)", offs, static_cast<void*>(pc));
return v8_buffer_.start();
}
}
return disasm::NameConverter::NameOfAddress(pc);
}
const char* V8NameConverter::NameInCode(byte* addr) const {
// The V8NameConverter is used for well known code, so we can "safely"
// dereference pointers in generated code.
return (code_ != NULL) ? reinterpret_cast<const char*>(addr) : "";
}
static void DumpBuffer(std::ostream* os, StringBuilder* out) {
(*os) << out->Finalize() << std::endl;
out->Reset();
}
static const int kOutBufferSize = 2048 + String::kMaxShortPrintLength;
static const int kRelocInfoPosition = 57;
static int DecodeIt(Isolate* isolate, std::ostream* os,
const V8NameConverter& converter, byte* begin, byte* end) {
SealHandleScope shs(isolate);
DisallowHeapAllocation no_alloc;
ExternalReferenceEncoder ref_encoder(isolate);
v8::internal::EmbeddedVector<char, 128> decode_buffer;
v8::internal::EmbeddedVector<char, kOutBufferSize> out_buffer;
StringBuilder out(out_buffer.start(), out_buffer.length());
byte* pc = begin;
disasm::Disassembler d(converter);
RelocIterator* it = NULL;
if (converter.code() != NULL) {
it = new RelocIterator(converter.code());
} else {
// No relocation information when printing code stubs.
}
int constants = -1; // no constants being decoded at the start
while (pc < end) {
// First decode instruction so that we know its length.
byte* prev_pc = pc;
if (constants > 0) {
SNPrintF(decode_buffer,
"%08x constant",
*reinterpret_cast<int32_t*>(pc));
constants--;
pc += 4;
} else {
int num_const = d.ConstantPoolSizeAt(pc);
if (num_const >= 0) {
SNPrintF(decode_buffer,
"%08x constant pool begin (num_const = %d)",
*reinterpret_cast<int32_t*>(pc), num_const);
constants = num_const;
pc += 4;
} else if (it != NULL && !it->done() && it->rinfo()->pc() == pc &&
it->rinfo()->rmode() == RelocInfo::INTERNAL_REFERENCE) {
// raw pointer embedded in code stream, e.g., jump table
byte* ptr = *reinterpret_cast<byte**>(pc);
SNPrintF(
decode_buffer, "%08" V8PRIxPTR " jump table entry %4" PRIuS,
reinterpret_cast<intptr_t>(ptr), static_cast<size_t>(ptr - begin));
pc += sizeof(ptr);
} else {
decode_buffer[0] = '\0';
pc += d.InstructionDecode(decode_buffer, pc);
}
}
// Collect RelocInfo for this instruction (prev_pc .. pc-1)
List<const char*> comments(4);
List<byte*> pcs(1);
List<RelocInfo::Mode> rmodes(1);
List<intptr_t> datas(1);
if (it != NULL) {
while (!it->done() && it->rinfo()->pc() < pc) {
if (RelocInfo::IsComment(it->rinfo()->rmode())) {
// For comments just collect the text.
comments.Add(reinterpret_cast<const char*>(it->rinfo()->data()));
} else {
// For other reloc info collect all data.
pcs.Add(it->rinfo()->pc());
rmodes.Add(it->rinfo()->rmode());
datas.Add(it->rinfo()->data());
}
it->next();
}
}
// Comments.
for (int i = 0; i < comments.length(); i++) {
out.AddFormatted(" %s", comments[i]);
DumpBuffer(os, &out);
}
// Instruction address and instruction offset.
out.AddFormatted("%p %4" V8PRIdPTRDIFF " ", static_cast<void*>(prev_pc),
prev_pc - begin);
// Instruction.
out.AddFormatted("%s", decode_buffer.start());
// Print all the reloc info for this instruction which are not comments.
for (int i = 0; i < pcs.length(); i++) {
// Put together the reloc info
RelocInfo relocinfo(isolate, pcs[i], rmodes[i], datas[i],
converter.code());
// Indent the printing of the reloc info.
if (i == 0) {
// The first reloc info is printed after the disassembled instruction.
out.AddPadding(' ', kRelocInfoPosition - out.position());
} else {
// Additional reloc infos are printed on separate lines.
DumpBuffer(os, &out);
out.AddPadding(' ', kRelocInfoPosition);
}
RelocInfo::Mode rmode = relocinfo.rmode();
if (RelocInfo::IsPosition(rmode)) {
if (RelocInfo::IsStatementPosition(rmode)) {
out.AddFormatted(" ;; debug: statement %" V8PRIdPTR,
relocinfo.data());
} else {
out.AddFormatted(" ;; debug: position %" V8PRIdPTR,
relocinfo.data());
}
} else if (rmode == RelocInfo::DEOPT_REASON) {
Deoptimizer::DeoptReason reason =
static_cast<Deoptimizer::DeoptReason>(relocinfo.data());
out.AddFormatted(" ;; debug: deopt reason '%s'",
Deoptimizer::GetDeoptReason(reason));
} else if (rmode == RelocInfo::DEOPT_ID) {
out.AddFormatted(" ;; debug: deopt index %d",
static_cast<int>(relocinfo.data()));
} else if (rmode == RelocInfo::EMBEDDED_OBJECT) {
HeapStringAllocator allocator;
StringStream accumulator(&allocator);
relocinfo.target_object()->ShortPrint(&accumulator);
base::SmartArrayPointer<const char> obj_name = accumulator.ToCString();
out.AddFormatted(" ;; object: %s", obj_name.get());
} else if (rmode == RelocInfo::EXTERNAL_REFERENCE) {
const char* reference_name = ref_encoder.NameOfAddress(
isolate, relocinfo.target_external_reference());
out.AddFormatted(" ;; external reference (%s)", reference_name);
} else if (RelocInfo::IsCodeTarget(rmode)) {
out.AddFormatted(" ;; code:");
Code* code = Code::GetCodeFromTargetAddress(relocinfo.target_address());
Code::Kind kind = code->kind();
if (code->is_inline_cache_stub()) {
if (kind == Code::LOAD_GLOBAL_IC &&
LoadGlobalICState::GetTypeofMode(code->extra_ic_state()) ==
INSIDE_TYPEOF) {
out.AddFormatted(" inside typeof,");
}
out.AddFormatted(" %s", Code::Kind2String(kind));
if (!IC::ICUseVector(kind)) {
InlineCacheState ic_state = IC::StateFromCode(code);
out.AddFormatted(" %s", Code::ICState2String(ic_state));
}
} else if (kind == Code::STUB || kind == Code::HANDLER) {
// Get the STUB key and extract major and minor key.
uint32_t key = code->stub_key();
uint32_t minor_key = CodeStub::MinorKeyFromKey(key);
CodeStub::Major major_key = CodeStub::GetMajorKey(code);
DCHECK(major_key == CodeStub::MajorKeyFromKey(key));
out.AddFormatted(" %s, %s, ", Code::Kind2String(kind),
CodeStub::MajorName(major_key));
out.AddFormatted("minor: %d", minor_key);
} else {
out.AddFormatted(" %s", Code::Kind2String(kind));
}
if (rmode == RelocInfo::CODE_TARGET_WITH_ID) {
out.AddFormatted(" (id = %d)", static_cast<int>(relocinfo.data()));
}
} else if (RelocInfo::IsRuntimeEntry(rmode) &&
isolate->deoptimizer_data() != NULL) {
// A runtime entry reloinfo might be a deoptimization bailout.
Address addr = relocinfo.target_address();
int id = Deoptimizer::GetDeoptimizationId(isolate,
addr,
Deoptimizer::EAGER);
if (id == Deoptimizer::kNotDeoptimizationEntry) {
id = Deoptimizer::GetDeoptimizationId(isolate,
addr,
Deoptimizer::LAZY);
if (id == Deoptimizer::kNotDeoptimizationEntry) {
id = Deoptimizer::GetDeoptimizationId(isolate,
addr,
Deoptimizer::SOFT);
if (id == Deoptimizer::kNotDeoptimizationEntry) {
out.AddFormatted(" ;; %s", RelocInfo::RelocModeName(rmode));
} else {
out.AddFormatted(" ;; soft deoptimization bailout %d", id);
}
} else {
out.AddFormatted(" ;; lazy deoptimization bailout %d", id);
}
} else {
out.AddFormatted(" ;; deoptimization bailout %d", id);
}
} else {
out.AddFormatted(" ;; %s", RelocInfo::RelocModeName(rmode));
}
}
DumpBuffer(os, &out);
}
// Emit comments following the last instruction (if any).
if (it != NULL) {
for ( ; !it->done(); it->next()) {
if (RelocInfo::IsComment(it->rinfo()->rmode())) {
out.AddFormatted(" %s",
reinterpret_cast<const char*>(it->rinfo()->data()));
DumpBuffer(os, &out);
}
}
}
delete it;
return static_cast<int>(pc - begin);
}
int Disassembler::Decode(Isolate* isolate, std::ostream* os, byte* begin,
byte* end, Code* code) {
V8NameConverter v8NameConverter(code);
return DecodeIt(isolate, os, v8NameConverter, begin, end);
}
#else // ENABLE_DISASSEMBLER
int Disassembler::Decode(Isolate* isolate, std::ostream* os, byte* begin,
byte* end, Code* code) {
return 0;
}
#endif // ENABLE_DISASSEMBLER
} // namespace internal
} // namespace v8