Update test.c

src/ast.cpp

@@ -154,6 +154,17 @@ namespace AST {
         return out.str();
     }
 
+    std::string WhileStatement::formatted() {
+        std::stringstream out{ "" };
+        out << "while (";
+        if (this->m_cond)
+            out << (*this->m_cond)->formatted();
+        out << ")";
+
+        out << "\n    then " << this->m_loop->formatted();
+        return out.str();
+    }
+
     std::string ReturnStatement::formatted() {
         std::stringstream out{ "" };
         out << "return ";

src/ast.h

@@ -453,6 +453,26 @@ namespace AST {
         virtual void typecheck(typecheck::State& state, typecheck::Scope& scope) override;
     };
 
+    class WhileStatement : public Statement {
+    private:
+        std::optional<std::unique_ptr<Expression>> m_cond;
+        std::unique_ptr<Statement> m_loop;
+    public:
+        WhileStatement(token::Metadata meta,
+            std::optional<std::unique_ptr<Expression>> cond,
+            std::unique_ptr<Statement> loop)
+            : Statement{ meta }
+            , m_cond{ std::move(cond) }
+            , m_loop{ std::move(loop) } {
+        }
+        virtual ~WhileStatement() override = default;
+        virtual std::string formatted() override;
+        virtual void codegen(codegen::Builder& builder, codegen::Scope& scope, codegen::StackAllocator& allocator) override;
+        virtual void codegen_alloca(codegen::StackAllocator& allocator) override;
+        virtual void typecheck_preprocess(typecheck::Scope& scope) override;
+        virtual void typecheck(typecheck::State& state, typecheck::Scope& scope) override;
+    };
+
     class TopLevelStatement : public Node {
     public:
         TopLevelStatement(token::Metadata meta) : Node{ meta } {}

src/codegen.cpp

@@ -596,6 +596,40 @@ namespace AST {
         builder.builder->SetInsertPoint(after_bb);
     }
 
+    void WhileStatement::codegen(codegen::Builder& builder, codegen::Scope& scope, codegen::StackAllocator& allocator) {
+        if (!builder.block)
+            return;
+
+        builder.builder->SetInsertPoint(builder.block);
+
+        auto function = builder.block->getParent();
+        auto cond_bb = llvm::BasicBlock::Create(*builder.context, "while-cond", function);
+        auto inner_bb = llvm::BasicBlock::Create(*builder.context, "while-inner", function);
+        auto after_bb = llvm::BasicBlock::Create(*builder.context, "while-after", function);
+
+        builder.builder->CreateBr(cond_bb);
+
+        // While condition
+        builder.builder->SetInsertPoint(cond_bb);
+        if (this->m_cond) {
+            auto cond_value = (*this->m_cond)->codegen(builder, scope, allocator);
+            builder.builder->CreateCondBr(cond_value.value, inner_bb, after_bb);
+        }
+        else {
+            builder.builder->CreateBr(inner_bb);
+        }
+
+        // While loop
+        builder.builder->SetInsertPoint(inner_bb);
+        builder.block = inner_bb;
+        this->m_loop->codegen(builder, scope, allocator);
+        builder.builder->CreateBr(cond_bb);
+
+        // After
+        builder.builder->SetInsertPoint(after_bb);
+        builder.block = after_bb;
+    }
+
 
     void Function::codegen(codegen::Builder& builder, codegen::Scope& scope) {
         std::shared_ptr<types::Type> ret_ty_ptr{ this->m_return_ty };

src/parsing.cpp

@@ -598,6 +598,30 @@ namespace parsing {
                     };
                     return std::pair{ std::unique_ptr<AST::Statement>{ statement }, false };
                 }
+                else if (inner.peek().type == token::Type::WhileKeyword) {
+                    inner.next();
+                    inner.expect(token::Type::Symbol, "(");
+
+                    std::optional<std::unique_ptr<AST::Expression>> cond;
+
+                    if (inner.peek().content != ")")
+                        cond = parse_expression(inner, scope).unwrap();
+                    inner.expect(token::Type::Symbol, ")");
+
+                    auto loop_res = parse_statement(inner, scope).unwrap();
+                    if (loop_res.second)
+                        inner.expect(token::Type::Symbol, ";");
+                    auto loop = std::move(loop_res.first);
+
+                    stream.m_position = inner.m_position;
+
+                    auto statement = new AST::WhileStatement{
+                        before_meta + stream.metadata(),
+                        std::move(cond),
+                        std::move(loop),
+                    };
+                    return std::pair{ std::unique_ptr<AST::Statement>{ statement }, false };
+                }
                 else if (auto init = parse_init_statement(inner, scope); init.ok()) {
                     stream.m_position = inner.m_position;
                     return std::pair{ std::unique_ptr<AST::Statement>{ init.unwrap() }, true };

src/stack_allocator.cpp

@@ -103,4 +103,10 @@ namespace AST {
             (*this->m_after)->codegen_alloca(allocator);
         this->m_loop->codegen_alloca(allocator);
     }
+
+    void WhileStatement::codegen_alloca(codegen::StackAllocator& allocator) {
+        if (this->m_cond)
+            (*this->m_cond)->codegen_alloca(allocator);
+        this->m_loop->codegen_alloca(allocator);
+    }
 }

src/tokens.cpp

@@ -61,6 +61,8 @@ namespace token {
             return "Else";
         case token::Type::ForKeyword:
             return "For";
+        case token::Type::WhileKeyword:
+            return "While";
 
         case token::Type::Whitespace:
             return "Whitespace";
@@ -227,6 +229,9 @@ namespace token {
                 else if (content == "for") {
                     type = token::Type::ForKeyword;
                 }
+                else if (content == "while") {
+                    type = token::Type::WhileKeyword;
+                }
                 tokens.push_back(token::Token{ type, content, meta + content.size() });
             }
             else if (iswhitespace(c)) {

src/tokens.h

@@ -17,6 +17,7 @@ namespace token {
         IfKeyword,
         ElseKeyword,
         ForKeyword,
+        WhileKeyword,
 
         Whitespace,
 

src/typechecker.cpp

@@ -645,20 +645,44 @@ namespace AST {
         auto bool_ty = std::shared_ptr<types::Type>{
             new types::FundamentalType{ false, types::FundamentalTypeKind::Bool } };
 
+        typecheck::Scope inner_scope{ scope };
+
         if (this->m_init)
-            (*this->m_init)->typecheck(state, scope);
+            (*this->m_init)->typecheck(state, inner_scope);
 
         if (this->m_cond) {
-            auto cond_ty = (*this->m_cond)->typecheck(state, scope, bool_ty).type;
+            auto cond_ty = (*this->m_cond)->typecheck(state, inner_scope, bool_ty).type;
 
             auto check_res = check_type(state, cond_ty, bool_ty);
             this->m_cond = handle_res(std::move(*this->m_cond), check_res, state);
         }
 
         if (this->m_after)
-            (*this->m_after)->typecheck(state, scope, {});
+            (*this->m_after)->typecheck(state, inner_scope, {});
 
-        this->m_loop->typecheck(state, scope);
+        this->m_loop->typecheck(state, inner_scope);
+    }
+
+    void WhileStatement::typecheck_preprocess(typecheck::Scope& scope) {
+        if (this->m_cond)
+            (*this->m_cond)->typecheck_preprocess(scope);
+        this->m_loop->typecheck_preprocess(scope);
+    }
+
+    void WhileStatement::typecheck(typecheck::State& state, typecheck::Scope& scope) {
+        auto bool_ty = std::shared_ptr<types::Type>{
+            new types::FundamentalType{ false, types::FundamentalTypeKind::Bool } };
+
+        typecheck::Scope inner_scope{ scope };
+
+        if (this->m_cond) {
+            auto cond_ty = (*this->m_cond)->typecheck(state, inner_scope, bool_ty).type;
+
+            auto check_res = check_type(state, cond_ty, bool_ty);
+            this->m_cond = handle_res(std::move(*this->m_cond), check_res, state);
+        }
+
+        this->m_loop->typecheck(state, inner_scope);
     }
 
     void Function::typecheck_preprocess(typecheck::Scope& scope) {

test.c

@@ -52,7 +52,11 @@ int main() {
     printf("2d array: %d!\n", twod_array[0][0]);
 
     for (int counter = 0; counter < 10; counter++)
-        printf("counter: %d\n", counter);
+        printf("for-counter: %d\n", counter);
+
+    int counter = 0;
+    while (counter < 10)
+        printf("while-counter: %d\n", counter++);
 
     return 0;
 }