Compiler: Add custom if statement methods

Author: adazem009

include/scratchcpp/dev/compiler.h

@@ -80,6 +80,10 @@ class LIBSCRATCHCPP_EXPORT Compiler
 
         void createVariableWrite(Variable *variable);
 
+        void beginIfStatement();
+        void beginElseBranch();
+        void endIf();
+
         void moveToIf(std::shared_ptr<Block> substack);
         void moveToIfElse(std::shared_ptr<Block> substack1, std::shared_ptr<Block> substack2);
         void moveToRepeatLoop(std::shared_ptr<Block> substack);

src/dev/engine/compiler.cpp

@@ -45,9 +45,15 @@ std::shared_ptr<ExecutableCode> Compiler::compile(std::shared_ptr<Block> startBl
     impl->block = startBlock;
 
     while (impl->block) {
-        if (impl->block->compileFunction())
+        if (impl->block->compileFunction()) {
+            assert(impl->customIfStatementCount == 0);
             impl->block->compile(this);
-        else {
+
+            if (impl->customIfStatementCount > 0) {
+                std::cerr << "error: if statement created by block '" << impl->block->opcode() << "' not terminated" << std::endl;
+                assert(false);
+            }
+        } else {
             std::cout << "warning: unsupported block: " << impl->block->opcode() << std::endl;
             impl->unsupportedBlocks.insert(impl->block->opcode());
         }
@@ -262,6 +268,35 @@ void Compiler::createVariableWrite(Variable *variable)
     impl->builder->createVariableWrite(variable);
 }
 
+/*!
+ * Starts a custom if statement.
+ * \note The if statement must be terminated using endIf() after compiling your block.
+ */
+void Compiler::beginIfStatement()
+{
+    impl->builder->beginIfStatement();
+    impl->customIfStatementCount++;
+}
+
+/*! Starts the else branch of custom if statement. */
+void Compiler::beginElseBranch()
+{
+    impl->builder->beginElseBranch();
+}
+
+/*! Ends custom if statement. */
+void Compiler::endIf()
+{
+    if (impl->customIfStatementCount == 0) {
+        std::cerr << "error: called Compiler::endIf() without an if statement";
+        assert(false);
+        return;
+    }
+
+    impl->builder->endIf();
+    impl->customIfStatementCount--;
+}
+
 /*! Jumps to the given if substack. */
 void Compiler::moveToIf(std::shared_ptr<Block> substack)
 {

src/dev/engine/compiler_p.h

@@ -31,6 +31,7 @@ struct CompilerPrivate
         Target *target = nullptr;
 
         std::shared_ptr<Block> block;
+        int customIfStatementCount = 0;
         std::vector<std::pair<std::pair<std::shared_ptr<Block>, std::shared_ptr<Block>>, SubstackType>> substackTree;
         bool substackHit = false;
         bool warp = false;

test/dev/compiler/compiler_test.cpp

@@ -571,6 +571,28 @@ TEST_F(CompilerTest, CreateVariableWrite)
     compile(compiler, block);
 }
 
+TEST_F(CompilerTest, CustomIfStatement)
+{
+    Compiler compiler(&m_engine, &m_target);
+    auto block = std::make_shared<Block>("", "");
+
+    block->setCompileFunction([](Compiler *compiler) {
+        EXPECT_CALL(*m_builder, beginIfStatement());
+        compiler->beginIfStatement();
+        EXPECT_CALL(*m_builder, endIf());
+        compiler->endIf();
+
+        EXPECT_CALL(*m_builder, beginIfStatement());
+        compiler->beginIfStatement();
+        EXPECT_CALL(*m_builder, beginElseBranch());
+        compiler->beginElseBranch();
+        EXPECT_CALL(*m_builder, endIf());
+        compiler->endIf();
+    });
+
+    compile(compiler, block);
+}
+
 TEST_F(CompilerTest, MoveToIf)
 {
     Compiler compiler(&m_engine, &m_target);