blob: 58c16b4a0235fa83dd7339ee3515415df74db648 [file] [log] [blame]
// Copyright (c) 2011 The Chromium 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 <stddef.h>
#include "courgette/assembly_program.h"
#include "base/logging.h"
#include "courgette/encoded_program.h"
#include "courgette/instruction_utils.h"
namespace courgette {
namespace {
// An instruction receptor that adds each received abs32/rel32 Label* to the
// matching VECTOR member variable. Template VECTOR allows code reuse for
// counting (CountingVector) and storage (std::vector).
template <template <typename T, typename... Args> class CONTAINER>
class LabelReceptor : public InstructionReceptor {
public:
using VECTOR = CONTAINER<Label*>;
LabelReceptor() = default;
~LabelReceptor() override = default;
VECTOR* mutable_abs32_vector() { return &abs32_vector_; }
VECTOR* mutable_rel32_vector() { return &rel32_vector_; }
// InstructionReceptor:
CheckBool EmitPeRelocs() override { return true; }
CheckBool EmitElfRelocation() override { return true; }
CheckBool EmitElfARMRelocation() override { return true; }
CheckBool EmitOrigin(RVA rva) override { return true; }
CheckBool EmitSingleByte(uint8_t byte) override { return true; }
CheckBool EmitMultipleBytes(const uint8_t* bytes, size_t len) override {
return true;
}
CheckBool EmitRel32(Label* label) override {
rel32_vector_.push_back(label);
return true;
}
CheckBool EmitRel32ARM(uint16_t op,
Label* label,
const uint8_t* arm_op,
uint16_t op_size) override {
rel32_vector_.push_back(label);
return true;
}
CheckBool EmitAbs32(Label* label) override {
abs32_vector_.push_back(label);
return true;
}
CheckBool EmitAbs64(Label* label) override {
abs32_vector_.push_back(label);
return true;
}
private:
VECTOR abs32_vector_;
VECTOR rel32_vector_;
DISALLOW_COPY_AND_ASSIGN(LabelReceptor);
};
} // namespace
AssemblyProgram::AssemblyProgram(ExecutableType kind, uint64_t image_base)
: kind_(kind), image_base_(image_base) {}
AssemblyProgram::~AssemblyProgram() = default;
void AssemblyProgram::PrecomputeLabels(RvaVisitor* abs32_visitor,
RvaVisitor* rel32_visitor) {
abs32_label_manager_.Read(abs32_visitor);
rel32_label_manager_.Read(rel32_visitor);
TrimLabels();
}
// Chosen empirically to give the best reduction in payload size for
// an update from daisy_3701.98.0 to daisy_4206.0.0.
const int AssemblyProgram::kLabelLowerLimit = 5;
void AssemblyProgram::TrimLabels() {
// For now only trim for ARM binaries.
if (kind() != EXE_ELF_32_ARM)
return;
int lower_limit = kLabelLowerLimit;
VLOG(1) << "TrimLabels: threshold " << lower_limit;
rel32_label_manager_.RemoveUnderusedLabels(lower_limit);
}
void AssemblyProgram::UnassignIndexes() {
abs32_label_manager_.UnassignIndexes();
rel32_label_manager_.UnassignIndexes();
}
void AssemblyProgram::DefaultAssignIndexes() {
abs32_label_manager_.DefaultAssignIndexes();
rel32_label_manager_.DefaultAssignIndexes();
}
void AssemblyProgram::AssignRemainingIndexes() {
abs32_label_manager_.AssignRemainingIndexes();
rel32_label_manager_.AssignRemainingIndexes();
}
Label* AssemblyProgram::FindAbs32Label(RVA rva) {
return abs32_label_manager_.Find(rva);
}
Label* AssemblyProgram::FindRel32Label(RVA rva) {
return rel32_label_manager_.Find(rva);
}
CheckBool AssemblyProgram::AnnotateLabels(const InstructionGenerator& gen) {
// Pass 1: Compute required space.
LabelReceptor<CountingVector> count_receptor;
if (!gen.Run(&count_receptor))
return false;
// Pass 2: Reserve and store annotations.
LabelReceptor<std::vector> annotate_receptor;
annotate_receptor.mutable_abs32_vector()->reserve(
count_receptor.mutable_abs32_vector()->size());
annotate_receptor.mutable_rel32_vector()->reserve(
count_receptor.mutable_rel32_vector()->size());
if (!gen.Run(&annotate_receptor))
return false;
// Move results to |abs32_label_annotations_| and |re32_label_annotations_|.
abs32_label_annotations_.swap(*annotate_receptor.mutable_abs32_vector());
rel32_label_annotations_.swap(*annotate_receptor.mutable_rel32_vector());
return true;
}
bool AssemblyProgram::PrepareEncodedProgram(EncodedProgram* encoded) const {
encoded->set_image_base(image_base_);
return encoded->ImportLabels(abs32_label_manager_, rel32_label_manager_);
}
} // namespace courgette