1 // Copyright 2016 The Chromium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #ifndef COURGETTE_INSTRUCTION_UTILS_H_
6 #define COURGETTE_INSTRUCTION_UTILS_H_
10 #include "base/callback.h"
11 #include "courgette/image_utils.h"
12 #include "courgette/memory_allocator.h"
16 // An interface to receive emitted instructions parsed from an executable.
17 class InstructionReceptor {
19 InstructionReceptor() = default;
21 InstructionReceptor(const InstructionReceptor&) = delete;
22 InstructionReceptor& operator=(const InstructionReceptor&) = delete;
24 virtual ~InstructionReceptor() = default;
26 // Generates an entire base relocation table.
27 virtual CheckBool EmitPeRelocs() = 0;
29 // Generates an ELF style relocation table for X86.
30 virtual CheckBool EmitElfRelocation() = 0;
32 // Following instruction will be assembled at address 'rva'.
33 virtual CheckBool EmitOrigin(RVA rva) = 0;
35 // Generates a single byte of data or machine instruction.
36 virtual CheckBool EmitSingleByte(uint8_t byte) = 0;
38 // Generates multiple bytes of data or machine instructions.
39 virtual CheckBool EmitMultipleBytes(const uint8_t* bytes, size_t len) = 0;
41 // Generates a 4-byte relative reference to address of 'label'.
42 virtual CheckBool EmitRel32(Label* label) = 0;
44 // Generates a 4-byte absolute reference to address of 'label'.
45 virtual CheckBool EmitAbs32(Label* label) = 0;
47 // Generates an 8-byte absolute reference to address of 'label'.
48 virtual CheckBool EmitAbs64(Label* label) = 0;
51 // A rerunable callback that emit instructions to a provided receptor. Returns
52 // true on success, and false otherwise.
53 using InstructionGenerator =
54 base::RepeatingCallback<CheckBool(InstructionReceptor*)>;
56 // A counter that increments via .push_back(), so it can be passed via template
57 // to substitute std::vector<T>, to count elements instead of storing them.
59 class CountingVector {
63 void push_back(const T& /* unused */) { ++size_; }
64 size_t size() const { return size_; }
70 } // namespace courgette
72 #endif // COURGETTE_INSTRUCTION_UTILS_H_