feat(opt): Faz 4 — Optimizasyon (sabit katlama + ölü kod eleme + --optimized)

- src/core/config.hpp: CompilerConfig (pass toggle'lar + maxFixpointRounds)
- src/opt/optimization_pass.hpp: soyut OptimizationPass tabanı
- src/opt/ast_clone.hpp: deepClone — tüm node tiplerini kapsayan derin klonlama
- src/opt/constant_folding.hpp: BinaryExpr(Literal,OP,Literal) → Literal;
  W002 sıfıra bölme uyarısı; + - * / % == != < > <= >= desteklenir
- src/opt/dead_code_elim.hpp: return/break/continue sonrası erişilemez
  deyimler Block'tan silinir
- src/opt/optimization_manager.hpp: AST klonlar, fixpoint döngüsüyle pass'leri
  çalıştırır (ADR-007/009)
- literal.hpp/.cpp: hasDirectValue/directIntValue — sentetik (token-sız) literal
- args.hpp: --optimized bayrağı
- cli/commands/ast.hpp: --optimized verilince klon üstünde optimize edilmiş AST
  gösterilir; orijinal dokunulmaz
- examples/opt_folding.sqt, examples/opt_dce.sqt: örnek fixture'lar

examples/opt_dce.sqt

@@ -0,0 +1,15 @@
+// Ölü kod eleme örneği
+// saqut ast file:examples/opt_dce.sqt --optimized
+// Beklenen: return sonrasındaki deyimler silinir.
+
+int foo() {
+    return 42;
+    int unreachable = 1;
+    int also_dead   = 2;
+}
+
+int main() {
+    int x = foo();
+    return x;
+    print("Bu satır asla çalışmaz");
+}

examples/opt_folding.sqt

@@ -0,0 +1,11 @@
+// Sabit katlama örneği
+// saqut ast file:examples/opt_folding.sqt --optimized
+// Beklenen: tüm BinaryExpression'lar Literal'e dönüşür.
+
+int main() {
+    int a = 2 + 3;
+    int b = 10 * 4;
+    int c = 100 / 5;
+    int d = a + 1;
+    return 1 * 10 + 2 * 5;
+}

src/cli/args.hpp

@@ -33,6 +33,7 @@ struct CliArgs {
     bool showHelp   = false;
     bool stdinMode  = false;
     bool compact    = false;  // --compact: boşluksuz JSON
+    bool optimized  = false;  // --optimized: sabit katlama + ölü kod eleme
 };
 
 // ============================================================================
@@ -72,6 +73,10 @@ inline CliArgs parseArgs(int argc, char* argv[]) {
             args.compact = true;
             continue;
         }
+        if (arg == "--optimized") {
+            args.optimized = true;
+            continue;
+        }
         if (arg.compare(0, 5, "file:") == 0) {
             args.positional.push_back(arg.substr(5));
             continue;

src/cli/commands/ast.hpp

@@ -1,5 +1,8 @@
 // ============================================================================
 // saQut CLI — ast komutu (JSON formatında AST hiyerarşisi + analiz)
+//
+// --optimized: sabit katlama + ölü kod eleme uygulandıktan sonra AST göster.
+//              Orijinal AST dokunulmaz; optimize edilmiş klon gösterilir.
 // ============================================================================
 
 #ifndef SAQUT_CLI_AST
@@ -10,6 +13,13 @@
 #include "cli/args.hpp"
 #include "tokenizer/tokenizer.hpp"
 #include "parser/parser.hpp"
+#include "symbol/symbol_table.hpp"
+#include "symbol/symbol_collector.hpp"
+#include "semantic/type_checker.hpp"
+#include "semantic/structural_validator.hpp"
+#include "diagnostic/diagnostic_engine.hpp"
+#include "core/config.hpp"
+#include "opt/optimization_manager.hpp"
 #include "json.hpp"
 
 inline int cmdAst(const CliArgs& args) {
@@ -28,9 +38,25 @@ inline int cmdAst(const CliArgs& args) {
         return 1;
     }
 
-    AstAnalysis analysis = analyzeAst(ast);
+    // ── Sembol + tip analizi (--optimized için gerekli; yalın ast'te opsiyonel) ──
+    SymbolTable      symbolTable;
+    DiagnosticEngine diag;
+    SymbolCollector(symbolTable, diag).collect(ast);
+    TypeChecker(symbolTable, diag).check(ast);
+    StructuralValidator(diag).validate(ast);
+
+    ASTNode* displayAst = ast; // gösterilecek ağaç (orijinal veya klon)
+    ASTNode* clonedAst  = nullptr;
+
+    if (args.optimized) {
+        CompilerConfig   cfg;
+        OptimizationManager mgr(cfg, diag);
+        clonedAst  = mgr.optimize(ast, &symbolTable);
+        displayAst = clonedAst;
+    }
+
+    AstAnalysis analysis = analyzeAst(displayAst);
 
-    // Çıktı hedefi
     std::ostream* out = &std::cout;
     std::ofstream outFile;
     if (!args.outputFile.empty()) {
@@ -40,12 +66,16 @@ inline int cmdAst(const CliArgs& args) {
 
     *out << "{\n"
          << "  \"ast\":\n"
-         << jsonIndent(2) << astToJson(ast, 2) << ",\n"
+         << jsonIndent(2) << astToJson(displayAst, 2) << ",\n"
          << "  \"analysis\": {\n"
          << analysisToJson(analysis) << "\n"
          << "  }\n"
          << "}\n";
 
+    // Optimizasyon uyarılarını (W002 vb.) stderr'e yazdır
+    if (args.optimized) diag.printAll(std::cerr);
+
+    if (clonedAst) delete clonedAst;
     delete ast;
     for (auto* t : tokens) delete t;
     return 0;

src/core/config.hpp

@@ -0,0 +1,11 @@
+#ifndef SAQUT_CORE_CONFIG
+#define SAQUT_CORE_CONFIG
+
+// Derleyici yapılandırması — hangi optimizasyon pass'lerinin çalışacağı.
+struct CompilerConfig {
+    bool optConstantFolding = true;
+    bool optDeadCodeElim    = true;
+    int  maxFixpointRounds  = 10;
+};
+
+#endif // SAQUT_CORE_CONFIG

src/opt/ast_clone.hpp

@@ -0,0 +1,286 @@
+// ============================================================================
+// saQut — AST Derin Klonlama (ADR-007)
+//
+// deepClone(node): tüm ağacı kopyalar, parent pointer'ları yeniden bağlar.
+// IdentifierNode::resolvedSymbol orijinal sembol tablosunu gösterir (read-only,
+// optimizasyon için yeterli — ADR-007).
+// ============================================================================
+
+#ifndef SAQUT_OPT_AST_CLONE
+#define SAQUT_OPT_AST_CLONE
+
+#include "parser/ast_node.hpp"
+#include "parser/nodes/program.hpp"
+#include "parser/nodes/declarations.hpp"
+#include "parser/nodes/statements.hpp"
+#include "parser/nodes/expressions.hpp"
+#include "parser/nodes/binary_expr.hpp"
+#include "parser/nodes/literal.hpp"
+#include "parser/nodes/identifier.hpp"
+
+inline ASTNode* deepClone(ASTNode* node);
+
+// ── Yardımcı: typed pointer klonla ve parent'ı bağla ────────────────────────
+static inline ASTNode* cloneChild(ASTNode* child, ASTNode* newParent) {
+    if (!child) return nullptr;
+    ASTNode* c = deepClone(child);
+    c->parent = newParent;
+    return c;
+}
+
+inline ASTNode* deepClone(ASTNode* node) {
+    if (!node) return nullptr;
+
+    switch (node->kind) {
+
+    // ── ProgramNode ──────────────────────────────────────────────────────────
+    case ASTKind::Program: {
+        auto* src = static_cast<ProgramNode*>(node);
+        auto* dst = new ProgramNode();
+        dst->loc = src->loc;
+        for (auto* ch : src->getChildren()) dst->addChild(deepClone(ch));
+        return dst;
+    }
+
+    // ── FunctionDeclNode ─────────────────────────────────────────────────────
+    case ASTKind::FunctionDecl: {
+        auto* src = static_cast<FunctionDeclNode*>(node);
+        auto* dst = new FunctionDeclNode();
+        dst->loc        = src->loc;
+        dst->name       = src->name;
+        dst->returnType = src->returnType;
+        for (auto* p : src->params) {
+            auto* cp = static_cast<VariableDeclNode*>(deepClone(p));
+            cp->parent = dst;
+            dst->params.push_back(cp);
+        }
+        for (auto* ch : src->getChildren()) dst->addChild(deepClone(ch));
+        return dst;
+    }
+
+    // ── VariableDeclNode ─────────────────────────────────────────────────────
+    case ASTKind::VariableDecl: {
+        auto* src = static_cast<VariableDeclNode*>(node);
+        auto* dst = new VariableDeclNode();
+        dst->loc         = src->loc;
+        dst->name        = src->name;
+        dst->varType     = src->varType;
+        dst->isReachable = src->isReachable;
+        if (src->initExpr) dst->initExpr = cloneChild(src->initExpr, dst);
+        for (auto* ch : src->getChildren()) dst->addChild(deepClone(ch));
+        return dst;
+    }
+
+    // ── StructDeclNode ───────────────────────────────────────────────────────
+    case ASTKind::StructDecl: {
+        auto* src = static_cast<StructDeclNode*>(node);
+        auto* dst = new StructDeclNode();
+        dst->loc  = src->loc;
+        dst->name = src->name;
+        for (auto* ch : src->getChildren()) dst->addChild(deepClone(ch));
+        return dst;
+    }
+
+    // ── BlockNode ────────────────────────────────────────────────────────────
+    case ASTKind::Block: {
+        auto* src = static_cast<BlockNode*>(node);
+        auto* dst = new BlockNode();
+        dst->loc         = src->loc;
+        dst->isReachable = src->isReachable;
+        for (auto* ch : src->getChildren()) dst->addChild(deepClone(ch));
+        return dst;
+    }
+
+    // ── IfStatementNode ──────────────────────────────────────────────────────
+    case ASTKind::IfStatement: {
+        auto* src = static_cast<IfStatementNode*>(node);
+        auto* dst = new IfStatementNode();
+        dst->loc         = src->loc;
+        dst->isReachable = src->isReachable;
+        dst->condition   = cloneChild(src->condition,  dst);
+        dst->thenBranch  = cloneChild(src->thenBranch, dst);
+        dst->elseBranch  = cloneChild(src->elseBranch, dst);
+        return dst;
+    }
+
+    // ── WhileStatementNode ───────────────────────────────────────────────────
+    case ASTKind::WhileStatement: {
+        auto* src = static_cast<WhileStatementNode*>(node);
+        auto* dst = new WhileStatementNode();
+        dst->loc         = src->loc;
+        dst->isReachable = src->isReachable;
+        dst->condition   = cloneChild(src->condition, dst);
+        dst->body        = cloneChild(src->body,      dst);
+        return dst;
+    }
+
+    // ── ForStatementNode ─────────────────────────────────────────────────────
+    case ASTKind::ForStatement: {
+        auto* src = static_cast<ForStatementNode*>(node);
+        auto* dst = new ForStatementNode();
+        dst->loc         = src->loc;
+        dst->isReachable = src->isReachable;
+        dst->init        = cloneChild(src->init,      dst);
+        dst->condition   = cloneChild(src->condition, dst);
+        dst->update      = cloneChild(src->update,    dst);
+        dst->body        = cloneChild(src->body,      dst);
+        return dst;
+    }
+
+    // ── DoWhileStatementNode ─────────────────────────────────────────────────
+    case ASTKind::DoWhileStatement: {
+        auto* src = static_cast<DoWhileStatementNode*>(node);
+        auto* dst = new DoWhileStatementNode();
+        dst->loc         = src->loc;
+        dst->isReachable = src->isReachable;
+        dst->body        = cloneChild(src->body,      dst);
+        dst->condition   = cloneChild(src->condition, dst);
+        return dst;
+    }
+
+    // ── ReturnStatementNode ──────────────────────────────────────────────────
+    case ASTKind::ReturnStatement: {
+        auto* src = static_cast<ReturnStatementNode*>(node);
+        auto* dst = new ReturnStatementNode();
+        dst->loc         = src->loc;
+        dst->isReachable = src->isReachable;
+        dst->value       = cloneChild(src->value, dst);
+        return dst;
+    }
+
+    // ── BreakStatementNode ───────────────────────────────────────────────────
+    case ASTKind::BreakStatement: {
+        auto* src = static_cast<BreakStatementNode*>(node);
+        auto* dst = new BreakStatementNode();
+        dst->loc         = src->loc;
+        dst->isReachable = src->isReachable;
+        return dst;
+    }
+
+    // ── ContinueStatementNode ────────────────────────────────────────────────
+    case ASTKind::ContinueStatement: {
+        auto* src = static_cast<ContinueStatementNode*>(node);
+        auto* dst = new ContinueStatementNode();
+        dst->loc         = src->loc;
+        dst->isReachable = src->isReachable;
+        return dst;
+    }
+
+    // ── ExpressionStatementNode ──────────────────────────────────────────────
+    case ASTKind::ExpressionStatement: {
+        auto* src = static_cast<ExpressionStatementNode*>(node);
+        auto* dst = new ExpressionStatementNode();
+        dst->loc         = src->loc;
+        dst->isReachable = src->isReachable;
+        dst->expression  = cloneChild(src->expression, dst);
+        return dst;
+    }
+
+    // ── BinaryExpressionNode ─────────────────────────────────────────────────
+    case ASTKind::BinaryExpression: {
+        auto* src = static_cast<BinaryExpressionNode*>(node);
+        auto* dst = new BinaryExpressionNode();
+        dst->loc          = src->loc;
+        dst->Operator     = src->Operator;
+        dst->resolvedType = src->resolvedType;
+        dst->isConstant   = src->isConstant;
+        dst->Left         = cloneChild(src->Left,  dst);
+        dst->Right        = cloneChild(src->Right, dst);
+        return dst;
+    }
+
+    // ── LiteralNode ──────────────────────────────────────────────────────────
+    case ASTKind::Literal: {
+        auto* src = static_cast<LiteralNode*>(node);
+        auto* dst = new LiteralNode();
+        dst->loc            = src->loc;
+        dst->literalType    = src->literalType;
+        dst->literalBase    = src->literalBase;
+        dst->isFloatValue   = src->isFloatValue;
+        dst->lexerToken     = src->lexerToken;   // orijinal token, salt-okunur
+        dst->parserToken    = src->parserToken;  // aynı token pointer, salt-okunur
+        dst->resolvedType   = src->resolvedType;
+        dst->isConstant     = src->isConstant;
+        dst->hasDirectValue = src->hasDirectValue;
+        dst->directIntValue = src->directIntValue;
+        return dst;
+    }
+
+    // ── IdentifierNode ───────────────────────────────────────────────────────
+    case ASTKind::Identifier: {
+        auto* src = static_cast<IdentifierNode*>(node);
+        auto* dst = new IdentifierNode();
+        dst->loc            = src->loc;
+        dst->lexerToken     = src->lexerToken;
+        dst->parserToken    = src->parserToken;
+        dst->resolvedSymbol = src->resolvedSymbol; // orijinal tablo, salt-okunur
+        dst->resolvedType   = src->resolvedType;
+        dst->isConstant     = src->isConstant;
+        return dst;
+    }
+
+    // ── PostfixNode ──────────────────────────────────────────────────────────
+    case ASTKind::Postfix: {
+        auto* src = static_cast<PostfixNode*>(node);
+        auto* dst = new PostfixNode();
+        dst->loc          = src->loc;
+        dst->Operator     = src->Operator;
+        dst->resolvedType = src->resolvedType;
+        dst->isConstant   = src->isConstant;
+        dst->operand      = cloneChild(src->operand, dst);
+        return dst;
+    }
+
+    // ── CallExpressionNode ───────────────────────────────────────────────────
+    case ASTKind::Call: {
+        auto* src = static_cast<CallExpressionNode*>(node);
+        auto* dst = new CallExpressionNode();
+        dst->loc          = src->loc;
+        dst->resolvedType = src->resolvedType;
+        dst->isConstant   = src->isConstant;
+        dst->callee       = cloneChild(src->callee, dst);
+        for (auto* arg : src->arguments) {
+            ASTNode* ca = deepClone(arg);
+            ca->parent = dst;
+            dst->arguments.push_back(ca);
+        }
+        return dst;
+    }
+
+    // ── MemberAccessNode ─────────────────────────────────────────────────────
+    case ASTKind::MemberAccess: {
+        auto* src = static_cast<MemberAccessNode*>(node);
+        auto* dst = new MemberAccessNode();
+        dst->loc          = src->loc;
+        dst->resolvedType = src->resolvedType;
+        dst->isConstant   = src->isConstant;
+        dst->member       = src->member;
+        dst->arrow        = src->arrow;
+        dst->object       = cloneChild(src->object, dst);
+        return dst;
+    }
+
+    // ── IndexExpressionNode ──────────────────────────────────────────────────
+    case ASTKind::IndexExpression: {
+        auto* src = static_cast<IndexExpressionNode*>(node);
+        auto* dst = new IndexExpressionNode();
+        dst->loc          = src->loc;
+        dst->resolvedType = src->resolvedType;
+        dst->isConstant   = src->isConstant;
+        dst->object       = cloneChild(src->object, dst);
+        dst->index        = cloneChild(src->index,  dst);
+        return dst;
+    }
+
+    // ── UnaryExpression ──────────────────────────────────────────────────────
+    // UnaryExpression şu anda ayrı bir sınıf değil; parser tarafından
+    // BinaryExpression veya PostfixNode olarak temsil ediliyor.
+    // Gelecekte eklenmesi gerekirse buraya eklenecek.
+    default:
+        // Bilinmeyen node tipi — klonlanamaz; orijinal döndür (güvenli değil ama
+        // derleme aşamasında tüm tipler yukarıda kaplanmalı).
+        return node;
+    }
+}
+
+#endif // SAQUT_OPT_AST_CLONE

src/opt/constant_folding.hpp

@@ -0,0 +1,304 @@
+// ============================================================================
+// saQut — Sabit Katlama (Constant Folding) Pass (ADR-009)
+//
+// BinaryExpression(Literal, OP, Literal) → Literal
+// Sadece tam sayı sabitleri katlanır; kayan nokta şimdilik dışarıda.
+// Derleme zamanı sıfıra bölme: W002 uyarısı verilir, katlama yapılmaz.
+// ============================================================================
+
+#ifndef SAQUT_OPT_CONSTANT_FOLDING
+#define SAQUT_OPT_CONSTANT_FOLDING
+
+#include <string>
+#include "opt/optimization_pass.hpp"
+#include "parser/nodes/binary_expr.hpp"
+#include "parser/nodes/literal.hpp"
+#include "parser/nodes/identifier.hpp"
+#include "parser/nodes/statements.hpp"
+#include "parser/nodes/expressions.hpp"
+#include "parser/nodes/declarations.hpp"
+#include "parser/nodes/program.hpp"
+#include "diagnostic/diagnostic_engine.hpp"
+
+class ConstantFoldingPass : public OptimizationPass {
+public:
+    explicit ConstantFoldingPass(DiagnosticEngine& diag) : diag_(diag) {}
+
+    bool run(ASTNode* root, SymbolTable*) override {
+        changed_ = false;
+        fold(root);
+        return changed_;
+    }
+
+    const std::string& name() const override {
+        static std::string n = "constant-folding";
+        return n;
+    }
+
+private:
+    DiagnosticEngine& diag_;
+    bool              changed_ = false;
+
+    // ── Literal değer okuma ──────────────────────────────────────────────────
+    static bool isIntLit(ASTNode* node) {
+        auto* lit = dynamic_cast<LiteralNode*>(node);
+        return lit && lit->literalType == LiteralType::INTEGER;
+    }
+
+    static int getIntVal(LiteralNode* lit) {
+        if (lit->hasDirectValue) return lit->directIntValue;
+        if (lit->parserToken.token) return std::stoi(lit->parserToken.token->token);
+        return 0;
+    }
+
+    // ── Operatör hesaplama ───────────────────────────────────────────────────
+    static bool canFoldOp(TokenType op) {
+        switch (op) {
+        case TokenType::PLUS:
+        case TokenType::MINUS:
+        case TokenType::STAR:
+        case TokenType::SLASH:
+        case TokenType::PERCENT:
+        case TokenType::EQUAL_EQUAL:
+        case TokenType::BANG_EQUAL:
+        case TokenType::LESS:
+        case TokenType::GREATER:
+        case TokenType::LESS_EQUAL:
+        case TokenType::GREATER_EQUAL:
+            return true;
+        default:
+            return false;
+        }
+    }
+
+    static int computeOp(TokenType op, int l, int r) {
+        switch (op) {
+        case TokenType::PLUS:          return l + r;
+        case TokenType::MINUS:         return l - r;
+        case TokenType::STAR:          return l * r;
+        case TokenType::SLASH:         return l / r;
+        case TokenType::PERCENT:       return l % r;
+        case TokenType::EQUAL_EQUAL:   return l == r ? 1 : 0;
+        case TokenType::BANG_EQUAL:    return l != r ? 1 : 0;
+        case TokenType::LESS:          return l <  r ? 1 : 0;
+        case TokenType::GREATER:       return l >  r ? 1 : 0;
+        case TokenType::LESS_EQUAL:    return l <= r ? 1 : 0;
+        case TokenType::GREATER_EQUAL: return l >= r ? 1 : 0;
+        default:                       return 0;
+        }
+    }
+
+    // ── Sentetik literal oluştur ─────────────────────────────────────────────
+    static LiteralNode* makeFoldedLit(int value, const SourceLocation& loc, const Type& type) {
+        auto* lit           = new LiteralNode();
+        lit->loc            = loc;
+        lit->literalType    = LiteralType::INTEGER;
+        lit->hasDirectValue = true;
+        lit->directIntValue = value;
+        lit->resolvedType   = type;
+        lit->isConstant     = true;
+        return lit;
+    }
+
+    // ── Ana ziyaretçi: bottom-up, pointer-by-reference ───────────────────────
+    // Dönüş değeri: aynı node veya yerine geçen yeni node.
+    // Folding yapıldıysa orijinal node silinir, yeni node döndürülür.
+    ASTNode* fold(ASTNode* node) {
+        if (!node) return nullptr;
+
+        switch (node->kind) {
+
+        // ── İfadeler ────────────────────────────────────────────────────────
+        case ASTKind::BinaryExpression: {
+            auto* bin = static_cast<BinaryExpressionNode*>(node);
+
+            // Alt ağaçları önce kat
+            ASTNode* newLeft  = fold(bin->Left);
+            if (newLeft != bin->Left) { bin->Left = newLeft; if (newLeft) newLeft->parent = bin; }
+
+            ASTNode* newRight = fold(bin->Right);
+            if (newRight != bin->Right) { bin->Right = newRight; if (newRight) newRight->parent = bin; }
+
+            // İki taraf da tam sayı sabiti ve operatör kesilebilir mi?
+            if (!isIntLit(bin->Left) || !isIntLit(bin->Right)) return bin;
+            if (!canFoldOp(bin->Operator)) return bin;
+
+            auto* llit = static_cast<LiteralNode*>(bin->Left);
+            auto* rlit = static_cast<LiteralNode*>(bin->Right);
+            int lv = getIntVal(llit);
+            int rv = getIntVal(rlit);
+
+            // W002: Derleme zamanı sıfıra bölme
+            if ((bin->Operator == TokenType::SLASH || bin->Operator == TokenType::PERCENT) && rv == 0) {
+                Diagnostic d;
+                d.level   = DiagLevel::Warning;
+                d.code    = "W002";
+                d.loc     = bin->loc;
+                d.message = "Derleme zamanı sıfıra bölme — katlama yapılmadı";
+                diag_.report(d);
+                return bin; // fold etme
+            }
+
+            int result = computeOp(bin->Operator, lv, rv);
+            LiteralNode* lit = makeFoldedLit(result, bin->loc, bin->resolvedType);
+
+            delete bin->Left;
+            delete bin->Right;
+            delete bin;
+            changed_ = true;
+            return lit;
+        }
+
+        case ASTKind::Postfix: {
+            auto* pf = static_cast<PostfixNode*>(node);
+            ASTNode* newOp = fold(pf->operand);
+            if (newOp != pf->operand) { pf->operand = newOp; if (newOp) newOp->parent = pf; }
+            return pf;
+        }
+
+        case ASTKind::Call: {
+            auto* call = static_cast<CallExpressionNode*>(node);
+            if (call->callee) {
+                ASTNode* nc = fold(call->callee);
+                if (nc != call->callee) { call->callee = nc; if (nc) nc->parent = call; }
+            }
+            for (auto*& arg : call->arguments) {
+                ASTNode* na = fold(arg);
+                if (na != arg) { arg = na; if (na) na->parent = call; }
+            }
+            return call;
+        }
+
+        case ASTKind::MemberAccess: {
+            auto* ma = static_cast<MemberAccessNode*>(node);
+            ASTNode* no = fold(ma->object);
+            if (no != ma->object) { ma->object = no; if (no) no->parent = ma; }
+            return ma;
+        }
+
+        case ASTKind::IndexExpression: {
+            auto* ix = static_cast<IndexExpressionNode*>(node);
+            ASTNode* no = fold(ix->object);
+            if (no != ix->object) { ix->object = no; if (no) no->parent = ix; }
+            ASTNode* ni = fold(ix->index);
+            if (ni != ix->index) { ix->index = ni; if (ni) ni->parent = ix; }
+            return ix;
+        }
+
+        // Literal ve Identifier değişmez
+        case ASTKind::Literal:
+        case ASTKind::Identifier:
+            return node;
+
+        // ── Deyimler (çocuklara iner) ────────────────────────────────────────
+        case ASTKind::ExpressionStatement: {
+            auto* es = static_cast<ExpressionStatementNode*>(node);
+            if (es->expression) {
+                ASTNode* ne = fold(es->expression);
+                if (ne != es->expression) { es->expression = ne; if (ne) ne->parent = es; }
+            }
+            return es;
+        }
+
+        case ASTKind::ReturnStatement: {
+            auto* rs = static_cast<ReturnStatementNode*>(node);
+            if (rs->value) {
+                ASTNode* nv = fold(rs->value);
+                if (nv != rs->value) { rs->value = nv; if (nv) nv->parent = rs; }
+            }
+            return rs;
+        }
+
+        case ASTKind::VariableDecl: {
+            auto* vd = static_cast<VariableDeclNode*>(node);
+            if (vd->initExpr) {
+                ASTNode* ni = fold(vd->initExpr);
+                if (ni != vd->initExpr) { vd->initExpr = ni; if (ni) ni->parent = vd; }
+            }
+            for (auto*& ch : vd->getChildren()) {
+                ASTNode* nc = fold(ch);
+                if (nc != ch) { ch = nc; if (nc) nc->parent = vd; }
+            }
+            return vd;
+        }
+
+        case ASTKind::IfStatement: {
+            auto* ifs = static_cast<IfStatementNode*>(node);
+            if (ifs->condition) {
+                ASTNode* nc = fold(ifs->condition);
+                if (nc != ifs->condition) { ifs->condition = nc; if (nc) nc->parent = ifs; }
+            }
+            if (ifs->thenBranch) fold(ifs->thenBranch);
+            if (ifs->elseBranch) fold(ifs->elseBranch);
+            return ifs;
+        }
+
+        case ASTKind::WhileStatement: {
+            auto* ws = static_cast<WhileStatementNode*>(node);
+            if (ws->condition) {
+                ASTNode* nc = fold(ws->condition);
+                if (nc != ws->condition) { ws->condition = nc; if (nc) nc->parent = ws; }
+            }
+            if (ws->body) fold(ws->body);
+            return ws;
+        }
+
+        case ASTKind::ForStatement: {
+            auto* fs = static_cast<ForStatementNode*>(node);
+            if (fs->init)      { ASTNode* n = fold(fs->init);      if (n != fs->init)      { fs->init      = n; if (n) n->parent = fs; } }
+            if (fs->condition) { ASTNode* n = fold(fs->condition);  if (n != fs->condition) { fs->condition = n; if (n) n->parent = fs; } }
+            if (fs->update)    { ASTNode* n = fold(fs->update);     if (n != fs->update)    { fs->update    = n; if (n) n->parent = fs; } }
+            if (fs->body)      fold(fs->body);
+            return fs;
+        }
+
+        case ASTKind::DoWhileStatement: {
+            auto* dw = static_cast<DoWhileStatementNode*>(node);
+            if (dw->body)      fold(dw->body);
+            if (dw->condition) {
+                ASTNode* nc = fold(dw->condition);
+                if (nc != dw->condition) { dw->condition = nc; if (nc) nc->parent = dw; }
+            }
+            return dw;
+        }
+
+        // ── Blok ve üst düzey ────────────────────────────────────────────────
+        case ASTKind::Block: {
+            auto* blk = static_cast<BlockNode*>(node);
+            for (auto*& ch : blk->getChildren()) {
+                ASTNode* nc = fold(ch);
+                if (nc != ch) { ch = nc; if (nc) nc->parent = blk; }
+            }
+            return blk;
+        }
+
+        case ASTKind::FunctionDecl: {
+            auto* fn = static_cast<FunctionDeclNode*>(node);
+            for (auto*& ch : fn->getChildren()) {
+                ASTNode* nc = fold(ch);
+                if (nc != ch) { ch = nc; if (nc) nc->parent = fn; }
+            }
+            return fn;
+        }
+
+        case ASTKind::Program: {
+            auto* prog = static_cast<ProgramNode*>(node);
+            for (auto*& ch : prog->getChildren()) {
+                ASTNode* nc = fold(ch);
+                if (nc != ch) { ch = nc; if (nc) nc->parent = prog; }
+            }
+            return prog;
+        }
+
+        default:
+            // Bilinmeyen veya işlenmeyen node — olduğu gibi bırak
+            for (auto*& ch : node->getChildren()) {
+                ASTNode* nc = fold(ch);
+                if (nc != ch) { ch = nc; if (nc) nc->parent = node; }
+            }
+            return node;
+        }
+    }
+};
+
+#endif // SAQUT_OPT_CONSTANT_FOLDING

src/opt/dead_code_elim.hpp

@@ -0,0 +1,110 @@
+// ============================================================================
+// saQut — Ölü Kod Eleme (Dead Code Elimination) Pass (ADR-009)
+//
+// Bir Block içinde ilk return/break/continue'dan sonra gelen deyimler
+// erişilemez (unreachable) olarak işaretlenir ve silinir.
+// ============================================================================
+
+#ifndef SAQUT_OPT_DEAD_CODE_ELIM
+#define SAQUT_OPT_DEAD_CODE_ELIM
+
+#include <string>
+#include <algorithm>
+#include "opt/optimization_pass.hpp"
+#include "parser/nodes/statements.hpp"
+#include "parser/nodes/declarations.hpp"
+#include "parser/nodes/expressions.hpp"
+#include "parser/nodes/program.hpp"
+
+class DeadCodeElimPass : public OptimizationPass {
+public:
+    bool run(ASTNode* root, SymbolTable*) override {
+        changed_ = false;
+        visit(root);
+        return changed_;
+    }
+
+    const std::string& name() const override {
+        static std::string n = "dead-code-elim";
+        return n;
+    }
+
+private:
+    bool changed_ = false;
+
+    void visit(ASTNode* node) {
+        if (!node) return;
+
+        switch (node->kind) {
+
+        // ── Block: ana DCE mantığı ───────────────────────────────────────────
+        case ASTKind::Block: {
+            auto* blk   = static_cast<BlockNode*>(node);
+            auto& ch    = blk->getChildren();
+            bool  term  = false;
+
+            for (auto* child : ch) {
+                if (term) {
+                    // Bu deyim erişilemez
+                    if (auto* sn = dynamic_cast<StatementNode*>(child)) {
+                        if (sn->isReachable) {
+                            sn->isReachable = false;
+                            changed_ = true;
+                        }
+                    }
+                }
+                if (child->kind == ASTKind::ReturnStatement ||
+                    child->kind == ASTKind::BreakStatement  ||
+                    child->kind == ASTKind::ContinueStatement)
+                    term = true;
+            }
+
+            // Erişilemez çocukları sil ve vektörden çıkar
+            ch.erase(std::remove_if(ch.begin(), ch.end(),
+                [](ASTNode* n) {
+                    auto* sn = dynamic_cast<StatementNode*>(n);
+                    return sn && !sn->isReachable;
+                }), ch.end());
+
+            // Alt bloklara da in
+            for (auto* child : ch) visit(child);
+            break;
+        }
+
+        // ── İf/While/For gövdelerine in ─────────────────────────────────────
+        case ASTKind::IfStatement: {
+            auto* ifs = static_cast<IfStatementNode*>(node);
+            visit(ifs->thenBranch);
+            visit(ifs->elseBranch);
+            break;
+        }
+
+        case ASTKind::WhileStatement: {
+            auto* ws = static_cast<WhileStatementNode*>(node);
+            visit(ws->body);
+            break;
+        }
+
+        case ASTKind::ForStatement: {
+            auto* fs = static_cast<ForStatementNode*>(node);
+            visit(fs->body);
+            break;
+        }
+
+        case ASTKind::DoWhileStatement: {
+            auto* dw = static_cast<DoWhileStatementNode*>(node);
+            visit(dw->body);
+            break;
+        }
+
+        // ── Üst düzey: fonksiyon gövdelerine in ─────────────────────────────
+        case ASTKind::FunctionDecl:
+        case ASTKind::Program:
+        default:
+            for (auto* ch : node->getChildren()) visit(ch);
+            break;
+        }
+    }
+};
+
+#endif // SAQUT_OPT_DEAD_CODE_ELIM

src/opt/optimization_manager.hpp

@@ -0,0 +1,56 @@
+// ============================================================================
+// saQut — Optimizasyon Yöneticisi (ADR-007, ADR-009)
+//
+// 1. AST'yi klonlar (orijinal dokunulmaz).
+// 2. Etkin pass'leri fixpoint döngüsüyle çalıştırır.
+// 3. Optimize edilmiş klon sahipliğini döndürür (caller delete eder).
+//
+// Fixpoint garantisi: her pass yalnızca küçülten dönüşümler yapar
+// (katlama: n düğüm → 1 düğüm; DCE: düğüm siler). Büyüten pass
+// (inlining vb.) eklenirse maxFixpointRounds tavanı zorunludur (ADR-009).
+// ============================================================================
+
+#ifndef SAQUT_OPT_MANAGER
+#define SAQUT_OPT_MANAGER
+
+#include <memory>
+#include <vector>
+#include "core/config.hpp"
+#include "opt/ast_clone.hpp"
+#include "opt/optimization_pass.hpp"
+#include "opt/constant_folding.hpp"
+#include "opt/dead_code_elim.hpp"
+#include "diagnostic/diagnostic_engine.hpp"
+#include "symbol/symbol_table.hpp"
+
+class OptimizationManager {
+public:
+    explicit OptimizationManager(const CompilerConfig& cfg, DiagnosticEngine& diag) {
+        if (cfg.optConstantFolding)
+            passes_.push_back(std::make_unique<ConstantFoldingPass>(diag));
+        if (cfg.optDeadCodeElim)
+            passes_.push_back(std::make_unique<DeadCodeElimPass>());
+        maxRounds_ = cfg.maxFixpointRounds;
+    }
+
+    // optimize: AST'yi klonlar ve optimize edilmiş kopyayı döndürür.
+    // Dönen pointer caller'a aittir (delete edilmeli).
+    ASTNode* optimize(ASTNode* root, SymbolTable* table) {
+        ASTNode* clone = deepClone(root);
+
+        for (int round = 0; round < maxRounds_; ++round) {
+            bool anyChange = false;
+            for (auto& pass : passes_)
+                if (pass->run(clone, table)) anyChange = true;
+            if (!anyChange) break;
+        }
+
+        return clone;
+    }
+
+private:
+    std::vector<std::unique_ptr<OptimizationPass>> passes_;
+    int maxRounds_ = 10;
+};
+
+#endif // SAQUT_OPT_MANAGER

src/opt/optimization_pass.hpp

@@ -0,0 +1,19 @@
+#ifndef SAQUT_OPT_PASS
+#define SAQUT_OPT_PASS
+
+#include <string>
+#include "parser/ast_node.hpp"
+#include "symbol/symbol_table.hpp"
+
+class OptimizationPass {
+public:
+    virtual ~OptimizationPass() = default;
+
+    // Pass'i çalıştırır. En az bir dönüşüm yaptıysa true döndürür.
+    // root: optimize edilecek klonlanmış AST kökü (sahiplik değişmez).
+    virtual bool run(ASTNode* root, SymbolTable* table) = 0;
+
+    virtual const std::string& name() const = 0;
+};
+
+#endif // SAQUT_OPT_PASS

src/parser/nodes/literal.cpp

@@ -6,17 +6,21 @@
 LiteralNode::LiteralNode() { kind = ASTKind::Literal; }
 
 void LiteralNode::log(int indent) {
+    std::string val = hasDirectValue ? std::to_string(directIntValue)
+                                     : (parserToken.token ? parserToken.token->token : "?");
     std::cout << padRight("", indent)
-              << "Literal {" << (parserToken.token ? parserToken.token->token : "?") << "} "
+              << "Literal {" << val << "} "
               << literalTypeToString(literalType);
+    if (isConstant) std::cout << " [folded]";
     if (literalType == LiteralType::INTEGER && literalBase != 10)
         std::cout << " (base " << literalBase << ")";
     std::cout << "\n";
 }
 
 std::string LiteralNode::toJson(int depth) {
-    std::string in = jsonIndent(depth);
+    std::string in  = jsonIndent(depth);
-    std::string val = parserToken.token ? parserToken.token->token : "?";
+    std::string val = hasDirectValue ? std::to_string(directIntValue)
+                                     : (parserToken.token ? parserToken.token->token : "?");
     std::ostringstream ss;
     ss << "{\n"
        << in << "  \"kind\": \"Literal\",\n"

src/parser/nodes/literal.hpp

@@ -12,6 +12,11 @@ public:
     int         literalBase  = 10;
     bool        isFloatValue = false;
 
+    // Sabit katlama (constant folding) tarafından üretilen sentetik literal.
+    // parserToken.token yerine bu değer kullanılır.
+    bool hasDirectValue  = false;
+    int  directIntValue  = 0;
+
     LiteralNode();
     void log(int indent = 0) override;
     std::string toJson(int depth = 0) override;