Add support for compiling function calls

Author: adazem009

src/engine/compiler.cpp

@@ -2,6 +2,7 @@
 
 #include "compiler.h"
 #include "engine.h"
+#include <cassert>
 
 using namespace libscratchcpp;
 using namespace vm;
@@ -11,6 +12,8 @@ Compiler::Compiler(Engine *engine, std::shared_ptr<Block> topLevelBlock) :
     m_engine(engine),
     m_block(topLevelBlock)
 {
+    assert(engine);
+    assert(topLevelBlock);
 }
 
 /*! Compiles the script. Use bytecode() to read the generated bytecode. */
@@ -118,6 +121,12 @@ void Compiler::addInput(Input *input)
     }
 }
 
+/*! Adds a function call to the bytecode (the OP_EXEC instruction). */
+void Compiler::addFunctionCall(BlockFunc f)
+{
+    addInstruction(OP_EXEC, { m_engine->functionIndex(f) });
+}
+
 /*! Returns the input with the given ID. */
 Input *Compiler::input(int id) const
 {

src/engine/compiler.h

@@ -32,6 +32,7 @@ class LIBSCRATCHCPP_EXPORT Compiler
 
         void addInstruction(vm::Opcode opcode, std::initializer_list<unsigned int> args = {});
         void addInput(Input *input);
+        void addFunctionCall(BlockFunc f);
 
         Input *input(int id) const;
         Field *field(int id) const;

src/engine/engine.cpp

@@ -307,6 +307,16 @@ BlockImpl Engine::resolveBlock(const std::string &opcode) const
     return nullptr;
 }
 
+/*! Returns the index of the given block function. */
+unsigned int Engine::functionIndex(BlockFunc f)
+{
+    auto it = std::find(m_functions.begin(), m_functions.end(), f);
+    if (it != m_functions.end())
+        return it - m_functions.begin();
+    m_functions.push_back(f);
+    return m_functions.size() - 1;
+}
+
 /*! Resolves the block and returns the block section in which it has been registered. */
 std::shared_ptr<IBlockSection> Engine::blockSection(const std::string &opcode) const
 {

src/engine/engine.h

@@ -45,6 +45,7 @@ class LIBSCRATCHCPP_EXPORT Engine
 
         void registerSection(std::shared_ptr<IBlockSection> section);
         BlockImpl resolveBlock(const std::string &opcode) const;
+        unsigned int functionIndex(BlockFunc f);
         std::shared_ptr<IBlockSection> blockSection(const std::string &opcode) const;
 
         std::vector<std::shared_ptr<Broadcast>> broadcasts() const;
@@ -71,6 +72,8 @@ class LIBSCRATCHCPP_EXPORT Engine
         std::vector<std::string> m_extensions;
         std::vector<std::shared_ptr<RunningScript>> m_runningScripts;
         std::unordered_map<std::shared_ptr<Block>, std::shared_ptr<VirtualMachine>> m_scripts;
+        std::vector<BlockFunc> m_functions;
+
         bool m_breakFrame = false;
         bool m_stayOnCurrentBlock = false;
         bool m_atomic = true;