CMakeLists.txt

@@ -72,7 +72,8 @@ target_compile_options(lib${PROJECT_NAME} PRIVATE ${warnings})
 # tests
 #
 
-add_executable(${PROJECT_NAME}-bytecode-test src/bytecode/tests.cc)
+add_executable(${PROJECT_NAME}-bytecode-test src/bytecode/tests.cc
+        common/overloaded.hh)
 target_link_libraries(${PROJECT_NAME}-bytecode-test lib${PROJECT_NAME} gtest_main)
 add_test(NAME tyche_bytecode_test COMMAND ${PROJECT_NAME}-bytecode-test)
 

doc/OPCODES

@@ -83,9 +83,9 @@ The bytecode file is composed of the following sections:
             [0:3]: Magic
             [4]:   VM format
  * [0x1] Index: pointers to each one of the sections, up to 8
-            Each pointer: 4 bits
+            Each pointer: 4 bytes
  * [0x2] Constants: all constants (such as strings) used in the code
-            * Table of 4-bit constant indexes with pointer to constant
+            * Table of 4-byte constant indexes with pointer to constant
             * Raw constant data
  * [0x3] Functions: Pointer to functions within the code
             [0:3]: function pointer

src/bytecode/bytearray.cc

@@ -4,7 +4,7 @@
 
 namespace tyche {
 
-void ByteArray::add_byte(uint32_t addr, uint8_t byte)
+void ByteArray::set_byte(uint32_t addr, uint8_t byte)
 {
     try {
         data_.at(addr) = byte;
@@ -14,39 +14,39 @@ void ByteArray::add_byte(uint32_t addr, uint8_t byte)
     }
 }
 
-void ByteArray::add_int(uint32_t addr, int32_t value)
+void ByteArray::set_int(uint32_t addr, int32_t value)
 {
     uint32_t zz = ((uint32_t)(value << 1)) ^ ((uint32_t)(value >> 31));
     while (zz > 0x7F) {
-        add_byte(addr++, (zz & 0x7F) | 0x80);
+        set_byte(addr++, (zz & 0x7F) | 0x80);
         zz >>= 7;
     }
-    add_byte(addr, zz & 0x7F);
+    set_byte(addr, zz & 0x7F);
 }
 
-void ByteArray::add_uint32(uint32_t addr, uint32_t value)
+void ByteArray::set_uint32(uint32_t addr, uint32_t value)
 {
-    add_byte(addr, (uint8_t)(value));
+    set_byte(addr, (uint8_t) (value));
-    add_byte(addr+1, (uint8_t)(value >> 8));
+    set_byte(addr+1, (uint8_t) (value >> 8));
-    add_byte(addr+2, (uint8_t)(value >> 16));
+    set_byte(addr+2, (uint8_t) (value >> 16));
-    add_byte(addr+3, (uint8_t)(value >> 24));
+    set_byte(addr+3, (uint8_t) (value >> 24));
 }
 
-void ByteArray::add_float(uint32_t addr, float value)
+void ByteArray::set_float(uint32_t addr, float value)
 {
     uint32_t bits;
     std::memcpy(&bits, &value, 4);
-    add_byte(addr, (uint8_t)(bits));
+    set_byte(addr, (uint8_t) (bits));
-    add_byte(addr+1, (uint8_t)(bits >> 8));
+    set_byte(addr+1, (uint8_t) (bits >> 8));
-    add_byte(addr+2, (uint8_t)(bits >> 16));
+    set_byte(addr+2, (uint8_t) (bits >> 16));
-    add_byte(addr+3, (uint8_t)(bits >> 24));
+    set_byte(addr+3, (uint8_t) (bits >> 24));
 }
 
-void ByteArray::add_string(uint32_t addr, std::string const& str)
+void ByteArray::set_string(uint32_t addr, std::string const& str)
 {
     for (uint8_t c: str)
-        add_byte(addr++, c);
+        set_byte(addr++, c);
-    add_byte(addr, 0);
+    set_byte(addr, 0);
 }
 
 uint8_t ByteArray::get_byte(uint32_t addr) const
@@ -97,4 +97,9 @@ std::pair<std::string, size_t> ByteArray::get_string(uint32_t addr) const
     return { data, data.size() + 1 };
 }
 
+void ByteArray::append_bytearray(ByteArray const& bytearray)
+{
+    data_.insert(data_.end(), bytearray.data().begin(), bytearray.data().end());
+}
+
 }

src/bytecode/bytearray.hh

@@ -13,17 +13,18 @@ public:
     ByteArray() = default;
     explicit ByteArray(std::vector<uint8_t> data) : data_(std::move(data)) {}
 
-    void add_byte(uint32_t addr, uint8_t byte);
+    void set_byte(uint32_t addr, uint8_t byte);
-    void add_uint32(uint32_t addr, uint32_t value);
+    void set_uint32(uint32_t addr, uint32_t value);
-    void add_int(uint32_t addr, int32_t value);
+    void set_int(uint32_t addr, int32_t value);
-    void add_float(uint32_t addr, float value);
+    void set_float(uint32_t addr, float value);
-    void add_string(uint32_t addr, std::string const& str);
+    void set_string(uint32_t addr, std::string const& str);
 
-    void append_byte(uint32_t addr, uint8_t byte) { add_byte(data_.size(), byte); }
+    void append_byte(uint8_t byte) { set_byte(data_.size(), byte); }
-    void append_uint32(uint32_t addr, uint32_t value) { add_uint32(data_.size(), value); }
+    void append_uint32(uint32_t value) { set_uint32(data_.size(), value); }
-    void append_int(uint32_t addr, int32_t value) { add_int(data_.size(), value); }
+    void append_int(int32_t value) { set_int(data_.size(), value); }
-    void append_float(uint32_t addr, float value) { add_float(data_.size(), value); }
+    void append_float(float value) { set_float(data_.size(), value); }
-    void append_string(uint32_t addr, std::string const& str) { add_string(data_.size(), str); }
+    void append_string(std::string const& str) { set_string(data_.size(), str); }
+    void append_bytearray(ByteArray const& bytearray);
 
     [[nodiscard]] uint8_t                        get_byte(uint32_t addr) const;
     [[nodiscard]] uint32_t                       get_uint32(uint32_t addr) const;
@@ -32,6 +33,7 @@ public:
     [[nodiscard]] std::pair<std::string, size_t> get_string(uint32_t addr) const;
 
     [[nodiscard]] std::vector<uint8_t> const& data() const { return data_; }
+    [[nodiscard]] size_t size() const { return data_.size(); }
 
 private:
     std::vector<uint8_t> data_;

src/bytecode/bytecode.cc

@@ -1,23 +1,44 @@
 #include "bytecode.hh"
+#include "../common/overloaded.hh"
 
 namespace tyche {
 
 Bytecode::Bytecode(BytecodePrototype const& bp)
 {
-    // header
-    byte_array_.add_uint32(0, MAGIC);
-    byte_array_.add_byte(4, VERSION);
-
     // constants
-    std::vector<uint32_t> constant_indexes;
+    std::vector<uint32_t> constant_table;
-    std::vector<uint8_t> constant_array;
+    ByteArray constant_array;
+    uint32_t idx = 0;
     for (auto const& constant: bp.constants) {
-
+        constant_table.emplace_back(idx);
+        std::visit(overloaded {
+            [&](int32_t i)            { constant_array.append_int(i); },
+            [&](float f)              { constant_array.append_float(f); },
+            [&](std::string const& s) { constant_array.append_string(s); },
+        }, constant);
+        idx = constant_array.size();
     }
 
-    // constants table
-
     // function table
+
+    //
+    // build binary
+    //
+
+    // header
+    byte_array_.set_uint32(0, MAGIC);
+    byte_array_.set_byte(4, VERSION);
+
+    // index - other entries created later
+    byte_array_.set_uint32(HEADER_SZ, HEADER_SZ + INDEX_SZ);
+
+    // constants
+    idx = HEADER_SZ + INDEX_SZ;
+    for (auto const& const_idx: constant_table) {
+        byte_array_.set_uint32(idx, const_idx);
+        idx += 4;
+    }
+    byte_array_.append_bytearray(constant_array);
 }
 
 uint32_t Bytecode::n_constants() const

src/bytecode/bytecode.hh

@@ -31,6 +31,8 @@ private:
     ByteArray byte_array_;
     static constexpr uint8_t VERSION = 1;
     static constexpr uint32_t MAGIC = 0x74b3c138;
+    static constexpr uint32_t HEADER_SZ = 16,
+                              INDEX_SZ = 8 * 4;
 };
 
 }

src/bytecode/tests.cc

@@ -18,10 +18,10 @@ TEST(ByteArray, ByteArray)
 
 #define TESTX(a, ...) test([](ByteArray& ba) { a; }, std::vector<uint8_t>({ __VA_ARGS__ }));
 
-    TESTX(ba.add_byte(1, 0xab), 0x00, 0xab)
+    TESTX(ba.set_byte(1, 0xab), 0x00, 0xab)
 
     ByteArray ba;
-    ba.add_byte(1, 0xab); ASSERT_EQ(ba.get_byte(1), 0xab);
+    ba.set_byte(1, 0xab); ASSERT_EQ(ba.get_byte(1), 0xab);
 
     ba.add_int(1, 12); ASSERT_EQ(ba.get_int(1), std::make_pair(12, 1));
     ba.add_int(1, -12); ASSERT_EQ(ba.get_int(1), std::make_pair(-12, 1));

src/common/overloaded.hh

@@ -0,0 +1,8 @@
+#ifndef TYCHE_OVERLOADED_HH
+#define TYCHE_OVERLOADED_HH
+
+// used by std::visitor
+template<class... Ts>
+struct overloaded : Ts... { using Ts::operator()...; };
+
+#endif //TYCHE_OVERLOADED_HH