refactor(codegen): split emission by responsibility

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

7 files changed, 1138 insertions, 1097 deletions

diff --git a/lib/CodeGen/Builtins.h b/lib/CodeGen/Builtins.h
new file mode 100644
index 0000000..34e36a9
--- /dev/null
+++ b/lib/CodeGen/Builtins.h
@@ -0,0 +1,37 @@
+#pragma once
+#include <string>
+
+namespace cps::detail {
+
+// Single source of truth for the built-in functions: name, arity and return
+// type. emitExpr checks arity against this table before dispatching, and
+// getExprTypeInfo reads the return type from it.
+struct BuiltinInfo {
+    const char *Name;
+    unsigned Arity;
+    const char *ReturnTypeName;
+};
+
+inline constexpr BuiltinInfo Builtins[] = {
+    {"LENGTH",     1, "INTEGER"},
+    {"MID",        3, "STRING"},
+    {"RIGHT",      2, "STRING"},
+    {"LEFT",       2, "STRING"},
+    {"LCASE",      1, "STRING"},
+    {"UCASE",      1, "STRING"},
+    {"ASC",        1, "INTEGER"},
+    {"CHR",        1, "STRING"},
+    {"IS_NUM",     1, "BOOLEAN"},
+    {"NUM_TO_STR", 1, "STRING"},
+    {"STR_TO_NUM", 1, "REAL"},
+    {"EOF",        1, "BOOLEAN"},
+};
+
+inline const BuiltinInfo *findBuiltin(const std::string &Name) {
+    for (const auto &B : Builtins) {
+        if (Name == B.Name) return &B;
+    }
+    return nullptr;
+}
+
+} // namespace cps::detail
diff --git a/lib/CodeGen/CodeGen.cc b/lib/CodeGen/CodeGen.cc
index 7e463db..6c6f682 100644
--- a/lib/CodeGen/CodeGen.cc
+++ b/lib/CodeGen/CodeGen.cc
@@ -1,10 +1,8 @@
 #include "cps/CodeGen.h"
 #include "cps/ArrayHandler.h"
-#include "cps/FileAST.h"
 #include "cps/FileHandler.h"
 #include "cps/ExceptionHandler.h"
-#include "cps/Lexer.h"
-#include "cps/TypeAST.h"
+#include "Builtins.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/Verifier.h"
 #include <cstdarg>
@@ -13,40 +11,7 @@
 using namespace llvm;
 using namespace cps;
 
-namespace {
-
-// Single source of truth for the built-in functions: name, arity and return
-// type. emitExpr checks arity against this table before dispatching, and
-// getExprTypeInfo reads the return type from it.
-struct BuiltinInfo {
-    const char *Name;
-    unsigned Arity;
-    const char *ReturnTypeName;
-};
-
-constexpr BuiltinInfo Builtins[] = {
-    {"LENGTH",     1, "INTEGER"},
-    {"MID",        3, "STRING"},
-    {"RIGHT",      2, "STRING"},
-    {"LEFT",       2, "STRING"},
-    {"LCASE",      1, "STRING"},
-    {"UCASE",      1, "STRING"},
-    {"ASC",        1, "INTEGER"},
-    {"CHR",        1, "STRING"},
-    {"IS_NUM",     1, "BOOLEAN"},
-    {"NUM_TO_STR", 1, "STRING"},
-    {"STR_TO_NUM", 1, "REAL"},
-    {"EOF",        1, "BOOLEAN"},
-};
-
-const BuiltinInfo *findBuiltin(const std::string &Name) {
-    for (const auto &B : Builtins) {
-        if (Name == B.Name) return &B;
-    }
-    return nullptr;
-}
-
-} // namespace
+using namespace cps::detail;
 
 CodeGen::~CodeGen() = default;
 
@@ -177,362 +142,6 @@ const TypeInfo *CodeGen::resolveType(const std::string &TypeName) const {
     return Types->resolve(TypeName);
 }
 
-const TypeInfo *CodeGen::getExprTypeInfo(ExprAST *Expr) const {
-    if (!Expr) return nullptr;
-
-    if (dynamic_cast<IntegerExprAST*>(Expr)) return resolveType("INTEGER");
-    if (dynamic_cast<RealExprAST*>(Expr)) return resolveType("REAL");
-    if (dynamic_cast<BooleanExprAST*>(Expr)) return resolveType("BOOLEAN");
-    if (dynamic_cast<CharExprAST*>(Expr)) return resolveType("CHAR");
-    if (dynamic_cast<StringExprAST*>(Expr)) return resolveType("STRING");
-    if (auto *Cast = dynamic_cast<CastExprAST*>(Expr))
-        return resolveType(Cast->getTypeName());
-
-    if (auto *Var = dynamic_cast<VariableExprAST*>(Expr)) {
-        const SymbolInfo *Info = getSymbolInfo(Var->getName());
-        if (Info) return resolveType(Info->TypeName);
-        if (const EnumConstant *EC = Types->lookupEnumConstant(Var->getName())) {
-            return resolveType(EC->TypeName);
-        }
-        return nullptr;
-    }
-
-    if (auto *Arr = dynamic_cast<ArrayAccessExprAST*>(Expr)) {
-        const SymbolInfo *Info = getSymbolInfo(Arr->getName());
-        return Info ? resolveType(Info->TypeName) : nullptr;
-    }
-
-    if (auto *D = dynamic_cast<DesignatorExprAST*>(Expr)) {
-        const SymbolInfo *Info = getSymbolInfo(D->getBaseName());
-        if (!Info) return nullptr;
-        std::string TypeName = Info->TypeName;
-        size_t Start = 0;
-        if (Info->IsArray) {
-            // SymbolInfo already holds the ELEMENT type name for arrays.
-            if (D->getAccesses().empty() || D->getAccesses()[0].Kind != AccessKind::Index)
-                return nullptr;
-            Start = 1;
-        }
-        for (size_t I = Start; I < D->getAccesses().size(); ++I) {
-            const TypeInfo *Cur = resolveType(TypeName);
-            if (!Cur) return nullptr;
-            const DesignatorAccess &A = D->getAccesses()[I];
-            if (A.Kind == AccessKind::Field) {
-                const RecordPayload *RP = Cur->asRecord();
-                const RecordFieldInfo *FI = RP ? RP->findField(A.FieldName) : nullptr;
-                if (!FI) return nullptr;
-                if (!FI->IsPublic) return nullptr;
-                TypeName = FI->TypeName;
-            } else if (A.Kind == AccessKind::Deref) {
-                const PointerPayload *PP = Cur->asPointer();
-                if (!PP) return nullptr;
-                TypeName = PP->PointeeTypeName;
-            } else {
-                return nullptr; // indexing a non-array
-            }
-        }
-        return resolveType(TypeName);
-    }
-
-    // ^x has no pseudocode type of its own; only the pointer admission in
-    // emitCoercedExpr may consume it.
-    if (dynamic_cast<AddrOfExprAST*>(Expr)) return nullptr;
-
-    if (auto *Unary = dynamic_cast<UnaryExprAST*>(Expr)) {
-        if (Unary->getOp() == tok_not) {
-            return resolveType("BOOLEAN");
-        }
-        const TypeInfo *Operand = getExprTypeInfo(Unary->getOperand());
-        if (Operand && Operand->isC()) return Types->promoteCScalar(Operand);
-        if (Operand && !Operand->isC() && !Operand->isUserKind())
-            return Operand->isReal() ? resolveType("REAL") : resolveType("INTEGER");
-        return nullptr;
-    }
-
-    if (auto *Bin = dynamic_cast<BinaryExprAST*>(Expr)) {
-        switch (Bin->getOp()) {
-            case tok_eq:
-            case tok_ne:
-            case '<':
-            case '>':
-            case tok_le:
-            case tok_ge:
-            case tok_and:
-            case tok_or:
-                return resolveType("BOOLEAN");
-            case '&':
-                return resolveType("STRING");
-            case '/':
-                return resolveType("REAL");
-            default:
-                break;
-        }
-
-        const TypeInfo *L = getExprTypeInfo(Bin->getLHS());
-        const TypeInfo *R = getExprTypeInfo(Bin->getRHS());
-        if ((L && L->isC()) || (R && R->isC())) return Types->commonCScalar(L, R);
-        // Enum arithmetic: E +/- INTEGER (enum on the left) yields the enum;
-        // every other user-kind combination has no type (emission rejects it).
-        if ((L && L->isUserKind()) || (R && R->isUserKind())) {
-            if (L && L->isEnum() && R && R->Kind == TypeKind::Integer &&
-                (Bin->getOp() == '+' || Bin->getOp() == '-')) {
-                return L;
-            }
-            return nullptr;
-        }
-        if ((L && L->Kind == TypeKind::Real) || (R && R->Kind == TypeKind::Real)) {
-            return resolveType("REAL");
-        }
-        return resolveType("INTEGER");
-    }
-
-    if (auto *Call = dynamic_cast<CallExprAST*>(Expr)) {
-        const std::string &Name = Call->getCallee();
-        if (const BuiltinInfo *B = findBuiltin(Name)) {
-            return resolveType(B->ReturnTypeName);
-        }
-        if (const FuncSig *Sig = FuncGen->getSignature(Name)) {
-            return resolveType(Sig->ReturnTypeName);
-        }
-
-        Function *CalleeF = TheModule->getFunction(Name);
-        if (!CalleeF) return resolveType("INTEGER");
-
-        Type *RetTy = CalleeF->getReturnType();
-        if (RetTy->isVoidTy()) return resolveType("VOID");
-        if (RetTy->isDoubleTy()) return resolveType("REAL");
-        if (RetTy->isIntegerTy(1)) return resolveType("BOOLEAN");
-        if (RetTy->isIntegerTy(8)) return resolveType("CHAR");
-        if (RetTy->isPointerTy()) return resolveType("STRING");
-        return resolveType("INTEGER");
-    }
-
-    return nullptr;
-}
-
-Value *CodeGen::coerceValueToType(Value *Val, const TypeInfo *TargetInfo) {
-    if (!Val || !TargetInfo || !TargetInfo->LLVMType) return nullptr;
-
-    if (Val->getType() == TargetInfo->LLVMType) {
-        return Val;
-    }
-
-    switch (TargetInfo->Kind) {
-        case TypeKind::Real:
-            if (Val->getType()->isDoubleTy()) return Val;
-            if (Val->getType()->isIntegerTy(1))
-                return Builder->CreateUIToFP(Val, Type::getDoubleTy(*TheContext), "bool_to_real");
-            if (Val->getType()->isIntegerTy(8))
-                return Builder->CreateUIToFP(Val, Type::getDoubleTy(*TheContext), "char_to_real");
-            if (Val->getType()->isIntegerTy())
-                return Builder->CreateSIToFP(Val, Type::getDoubleTy(*TheContext), "int_to_real");
-            break;
-
-        case TypeKind::Integer:
-            if (Val->getType()->isIntegerTy(64)) return Val;
-            if (Val->getType()->isDoubleTy())
-                return Builder->CreateFPToSI(Val, Type::getInt64Ty(*TheContext), "real_to_int");
-            if (Val->getType()->isIntegerTy(1))
-                return Builder->CreateZExt(Val, Type::getInt64Ty(*TheContext), "bool_to_int");
-            if (Val->getType()->isIntegerTy(8))
-                return Builder->CreateZExt(Val, Type::getInt64Ty(*TheContext), "char_to_int");
-            if (Val->getType()->isIntegerTy())
-                return Builder->CreateSExtOrTrunc(Val, Type::getInt64Ty(*TheContext), "int_cast");
-            break;
-
-        case TypeKind::Boolean:
-            if (Val->getType()->isIntegerTy(1)) return Val;
-            if (Val->getType()->isIntegerTy())
-                return Builder->CreateICmpNE(Val, Constant::getNullValue(Val->getType()), "to_bool");
-            if (Val->getType()->isDoubleTy())
-                return Builder->CreateFCmpONE(Val, ConstantFP::get(*TheContext, APFloat(0.0)), "to_bool");
-            if (Val->getType()->isPointerTy())
-                return Builder->CreateICmpNE(Val,
-                                             ConstantPointerNull::get(cast<PointerType>(Val->getType())),
-                                             "ptr_to_bool");
-            break;
-
-        case TypeKind::Char:
-            if (Val->getType()->isIntegerTy(8)) return Val;
-            if (Val->getType()->isIntegerTy(1))
-                return Builder->CreateZExt(Val, Type::getInt8Ty(*TheContext), "bool_to_char");
-            if (Val->getType()->isDoubleTy())
-                return Builder->CreateFPToUI(Val, Type::getInt8Ty(*TheContext), "real_to_char");
-            if (Val->getType()->isIntegerTy())
-                return Builder->CreateTruncOrBitCast(Val, Type::getInt8Ty(*TheContext), "int_to_char");
-            break;
-
-        case TypeKind::String:
-            if (Val->getType()->isPointerTy()) return Val;
-            if (Val->getType()->isIntegerTy(1)) {
-                return Builder->CreateSelect(Val, TrueStr, FalseStr, "bool_to_str");
-            }
-            if (Val->getType()->isDoubleTy()) {
-                return StrConvHandler->emitNumToStr(Val, true);
-            }
-            if (Val->getType()->isIntegerTy(8)) {
-                Value *Mem = Builder->CreateCall(MallocFunc,
-                                                 ConstantInt::get(*TheContext, APInt(64, 2)),
-                                                 "char_str");
-                Builder->CreateStore(Val, Mem);
-                Value *NullPtr = Builder->CreateInBoundsGEP(Type::getInt8Ty(*TheContext),
-                                                            Mem,
-                                                            ConstantInt::get(*TheContext, APInt(64, 1)));
-                Builder->CreateStore(ConstantInt::get(Type::getInt8Ty(*TheContext), 0), NullPtr);
-                return Mem;
-            }
-            if (Val->getType()->isIntegerTy()) {
-                Value *AsInt = coerceValueToType(Val, resolveType("INTEGER"));
-                return AsInt ? StrConvHandler->emitNumToStr(AsInt, false) : nullptr;
-            }
-            break;
-
-        case TypeKind::Void:
-            return nullptr;
-
-        // Enum/Record/Pointer identity lives in the type NAME; at this level
-        // an enum is a plain i64 and a pointer a plain ptr, so nothing can be
-        // checked here. emitCoercedExpr is the only legitimate door.
-        case TypeKind::Enum:
-        case TypeKind::Record:
-        case TypeKind::Pointer:
-        case TypeKind::CScalar:
-        case TypeKind::CPointer:
-            reportError("Internal: a %s value reached representation coercion without a name-level check",
-                        TargetInfo->Name.c_str());
-            return nullptr;
-    }
-
-    reportError("Cannot coerce value of LLVM type to target type %s",
-            TargetInfo->Name.c_str());
-    return nullptr;
-}
-
-void CodeGen::emitDeclareStmt(DeclareStmtAST *Stmt) {
-    const TypeInfo *Info = resolveType(Stmt->getType());
-    if (!Info || !Info->LLVMType || Info->isVoid()) {
-        reportError("Unknown type %s", Stmt->getType().c_str());
-        return;
-    }
-    if (Types->lookupEnumConstant(Stmt->getName())) {
-        reportError("'%s' is an enum value and cannot be declared as a variable",
-                    Stmt->getName().c_str());
-        return;
-    }
-    if (Types->resolve(Stmt->getName())) {
-        reportError("'%s' is a type name and cannot be declared as a variable",
-                    Stmt->getName().c_str());
-        return;
-    }
-
-    Function *TheFunction = Builder->GetInsertBlock()->getParent();
-    AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, Info->LLVMType, Stmt->getName());
-
-    Value *InitVal = nullptr;
-    if (Info->isString()) {
-        InitVal = EmptyStringStr;
-    } else {
-        InitVal = Types->getZeroValue(Info->Name);
-    }
-
-    if (InitVal) {
-        Builder->CreateStore(InitVal, Alloca);
-    }
-
-    registerSymbol(Stmt->getName(), Alloca, Info->Name, false);
-}
-
-Value *CodeGen::emitStringNullGuard(Value *StrVal) {
-    if (!StrVal || !StrVal->getType()->isPointerTy()) return StrVal;
-    Value *IsNull = Builder->CreateICmpEQ(StrVal,
-                                          ConstantPointerNull::get(cast<PointerType>(StrVal->getType())),
-                                          "str_is_null");
-    return Builder->CreateSelect(IsNull, EmptyStringStr, StrVal, "safe_str");
-}
-
-void CodeGen::emitOutputValue(Value *Val, const TypeInfo *Info, bool AppendNewline) {
-    if (!Val || !Info) return;
-
-    std::vector<Value*> Args;
-    Value *Fmt = nullptr;
-
-    // Exhaustive over TypeKind (no default): the compiler warns when a new
-    // kind is added without deciding its OUTPUT story.
-    switch (Info->Kind) {
-    case TypeKind::Real:
-        Fmt = AppendNewline
-            ? PrintfFloatFormatStr
-            : Builder->CreateGlobalString("%f", "fmt_flt_inline", 0, TheModule.get());
-        Args.push_back(Fmt);
-        Args.push_back(Val);
-        break;
-
-    case TypeKind::Boolean: {
-        Value *BoolVal = coerceValueToType(Val, resolveType("BOOLEAN"));
-        Fmt = AppendNewline
-            ? PrintfStringFormatStr
-            : Builder->CreateGlobalString("%s", "fmt_str_inline", 0, TheModule.get());
-        Args.push_back(Fmt);
-        Args.push_back(Builder->CreateSelect(BoolVal, TrueStr, FalseStr));
-        break;
-    }
-
-    case TypeKind::String: {
-        Value *StrVal = emitStringNullGuard(Val);
-        Fmt = AppendNewline
-            ? PrintfStringFormatStr
-            : Builder->CreateGlobalString("%s", "fmt_str_inline", 0, TheModule.get());
-        Args.push_back(Fmt);
-        Args.push_back(StrVal);
-        break;
-    }
-
-    case TypeKind::Char: {
-        Value *CharVal = coerceValueToType(Val, resolveType("CHAR"));
-        Value *Promoted = Builder->CreateZExt(CharVal, Type::getInt32Ty(*TheContext), "char_for_printf");
-        Fmt = AppendNewline
-            ? PrintfCharFormatStr
-            : Builder->CreateGlobalString("%c", "fmt_chr_inline", 0, TheModule.get());
-        Args.push_back(Fmt);
-        Args.push_back(Promoted);
-        break;
-    }
-
-    case TypeKind::Integer:
-    case TypeKind::Enum: { // an enum prints its ordinal (user decision)
-        Value *IntVal = Info->isEnum() ? Val : coerceValueToType(Val, resolveType("INTEGER"));
-        Fmt = AppendNewline
-            ? PrintfFormatStr
-            : Builder->CreateGlobalString("%lld", "fmt_int_inline", 0, TheModule.get());
-        Args.push_back(Fmt);
-        Args.push_back(IntVal);
-        break;
-    }
-
-    case TypeKind::Record:
-        reportError("Cannot OUTPUT a value of record type %s; output its fields individually",
-                    Info->Name.c_str());
-        return;
-
-    case TypeKind::Pointer:
-        reportError("Cannot OUTPUT a value of pointer type %s", Info->Name.c_str());
-        return;
-
-    case TypeKind::CScalar:
-        emitCOutput(Val, Info, AppendNewline);
-        return;
-    case TypeKind::CPointer:
-        reportError("OUTPUT is not supported for type %s", Info->Name.c_str());
-        return;
-
-    case TypeKind::Void:
-        reportError("Cannot OUTPUT a VOID value");
-        return;
-    }
-
-    Builder->CreateCall(PrintfFunc, Args);
-}
-
 void CodeGen::compile(const std::vector<std::unique_ptr<StmtAST>> &Statements) {
     FunctionType *FT = FunctionType::get(Type::getInt32Ty(*TheContext), false);
     Function *F = Function::Create(FT, Function::ExternalLinkage, "main", TheModule.get());
@@ -581,268 +190,6 @@ void CodeGen::print(raw_ostream &Output) {
     TheModule->print(Output, nullptr);
 }
 
-Value *CodeGen::emitExpr(ExprAST *Expr) {
-    if (auto *Cast = dynamic_cast<CastExprAST*>(Expr)) return emitCast(Cast);
-    if (!Expr) return nullptr;
-
-    if (auto *Num = dynamic_cast<IntegerExprAST*>(Expr)) {
-        return ConstantInt::get(*TheContext, APInt(64, Num->getVal(), true));
-    }
-
-    if (auto *Real = dynamic_cast<RealExprAST*>(Expr)) {
-        return ConstantFP::get(*TheContext, APFloat(Real->getVal()));
-    }
-
-    if (auto *Bool = dynamic_cast<BooleanExprAST*>(Expr)) {
-        return ConstantInt::get(*TheContext, APInt(1, Bool->getVal() ? 1 : 0));
-    }
-
-    if (auto *Chr = dynamic_cast<CharExprAST*>(Expr)) {
-        return ConstantInt::get(Type::getInt8Ty(*TheContext), static_cast<unsigned char>(Chr->getVal()));
-    }
-
-    if (auto *Str = dynamic_cast<StringExprAST*>(Expr)) {
-        return StrHandler->createLiteral(Str->getVal());
-    }
-
-    if (auto *Var = dynamic_cast<VariableExprAST*>(Expr)) {
-        const SymbolInfo *Info = getSymbolInfo(Var->getName());
-        if (!Info) {
-            // Enum values are bare identifiers; collisions with variables are
-            // rejected at declaration time, so the order here cannot shadow.
-            if (const EnumConstant *EC = Types->lookupEnumConstant(Var->getName())) {
-                return ConstantInt::get(*TheContext, APInt(64, static_cast<uint64_t>(EC->Ordinal), true));
-            }
-            reportError("Unknown variable name %s", Var->getName().c_str());
-            return nullptr;
-        }
-        if (Info->IsArray) {
-            return Info->Storage;
-        }
-
-        const TypeInfo *TypeInfo = resolveType(Info->TypeName);
-        if (!TypeInfo || !TypeInfo->LLVMType) {
-            reportError("Unknown type for variable %s", Var->getName().c_str());
-            return nullptr;
-        }
-
-        Value *Loaded = Builder->CreateLoad(TypeInfo->LLVMType, Info->Storage, Var->getName().c_str());
-        if (TypeInfo->isString()) {
-            Loaded = emitStringNullGuard(Loaded);
-        }
-        return Loaded;
-    }
-
-    if (auto *ArrAcc = dynamic_cast<ArrayAccessExprAST*>(Expr)) {
-        return Arrays->emitArrayAccess(ArrAcc, *this);
-    }
-
-    if (auto *Unary = dynamic_cast<UnaryExprAST*>(Expr)) {
-        if (Unary->getOp() == tok_not) {
-            const TypeInfo *Info = getExprTypeInfo(Unary->getOperand());
-            Value *Operand = Info && Info->isC()
-                ? convertNumericValue(emitExpr(Unary->getOperand()), Info, resolveType("BOOLEAN"))
-                : emitCoercedExpr(Unary->getOperand(), resolveType("BOOLEAN"));
-            if (Info && Info->Kind == TypeKind::CPointer) {
-                reportError("NOT does not support C pointer operands");
-                return nullptr;
-            }
-            if (!Operand) return nullptr;
-            return Builder->CreateNot(Operand, "nottmp");
-        }
-        if (Unary->getOp() == '-') {
-            const TypeInfo *Info = getExprTypeInfo(Unary->getOperand());
-            if (Info && Info->Kind == TypeKind::CScalar && !Info->isVoid()) {
-                const TypeInfo *Promoted = Types->promoteCScalar(Info);
-                Value *Operand = convertNumericValue(emitExpr(Unary->getOperand()), Info, Promoted);
-                if (!Operand) return nullptr;
-                return Promoted->isReal() ? Builder->CreateFNeg(Operand, "c_neg")
-                                          : Builder->CreateNeg(Operand, "c_neg");
-            }
-            if (!Info || Info->isC() || Info->isUserKind() || Info->isString() || Info->isVoid()) {
-                reportError("Unary '-' requires a supported numeric operand");
-                return nullptr;
-            }
-            Value *Operand = emitExpr(Unary->getOperand());
-            if (!Operand) return nullptr;
-            return ArithHandler->emitBinaryOp('-', ConstantInt::get(Type::getInt64Ty(*TheContext), 0),
-                                             Operand, 0);
-        }
-        return nullptr;
-    }
-
-    if (auto *Bin = dynamic_cast<BinaryExprAST*>(Expr)) {
-        // Whole arrays evaluate to raw data pointers and ^x to raw addresses;
-        // neither is a value any operator may consume.
-        if (isWholeArrayVar(Bin->getLHS()) || isWholeArrayVar(Bin->getRHS())) {
-            reportError("A whole array cannot be used as an operand; index it");
-            return nullptr;
-        }
-        if (dynamic_cast<AddrOfExprAST*>(Bin->getLHS()) ||
-            dynamic_cast<AddrOfExprAST*>(Bin->getRHS())) {
-            reportError("'^' (address-of) can only be used where a pointer type is expected");
-            return nullptr;
-        }
-
-        // Enum/Record/Pointer operands never reach ArithmeticHandler or the
-        // '&' path: their admissible operations are decided by name here.
-        const TypeInfo *LT = getExprTypeInfo(Bin->getLHS());
-        const TypeInfo *RT = getExprTypeInfo(Bin->getRHS());
-        if ((LT && LT->isC()) || (RT && RT->isC())) {
-            return emitCBinaryOp(Bin, LT, RT);
-        }
-        if ((LT && LT->isUserKind()) || (RT && RT->isUserKind())) {
-            return emitUserKindBinaryOp(Bin, LT, RT);
-        }
-
-        Value *L = emitExpr(Bin->getLHS());
-        Value *R = emitExpr(Bin->getRHS());
-        if (!L || !R) return nullptr;
-        if (Bin->getOp() == '&') {
-            L = coerceValueToType(L, resolveType("STRING"));
-            R = coerceValueToType(R, resolveType("STRING"));
-            if (!L || !R) return nullptr;
-            return StrHandler->emitConcat(L, R);
-        }
-        // STRING and explicit pointers share LLVM's ptr representation;
-        // string comparisons must dispatch on the pseudocode type.
-        switch (Bin->getOp()) {
-        case tok_eq: case tok_ne: case '<': case '>': case tok_le: case tok_ge:
-            if ((LT && LT->isString()) || (RT && RT->isString())) {
-                if (!(LT && LT->isString() && RT && RT->isString())) {
-                    reportError("STRING comparison requires two STRING operands (line %d)", Bin->getLine());
-                    return nullptr;
-                }
-                return StrHandler->emitCompare(Bin->getOp(), L, R);
-            }
-            break;
-        default:
-            break;
-        }
-        return ArithHandler->emitBinaryOp(Bin->getOp(), L, R, Bin->getLine());
-    }
-
-    if (auto *Call = dynamic_cast<CallExprAST*>(Expr)) {
-        std::string Name = Call->getCallee();
-        if (const BuiltinInfo *B = findBuiltin(Name)) {
-            if (Call->getArgs().size() != B->Arity) {
-                reportError("%s expects %u arg%s", B->Name, B->Arity, B->Arity == 1 ? "" : "s");
-                return nullptr;
-            }
-        }
-        if (Name == "LENGTH") {
-            Value *Str = emitCoercedExpr(Call->getArgs()[0].get(), resolveType("STRING"));
-            if (!Str) return nullptr;
-            return StrHandler->emitLength(Str);
-        }
-        if (Name == "MID") {
-            Value *Str = emitCoercedExpr(Call->getArgs()[0].get(), resolveType("STRING"));
-            Value *Start = emitCoercedExpr(Call->getArgs()[1].get(), resolveType("INTEGER"));
-            Value *Len = emitCoercedExpr(Call->getArgs()[2].get(), resolveType("INTEGER"));
-            if (!Str || !Start || !Len) return nullptr;
-            return StrHandler->emitMid(Str, Start, Len);
-        }
-        if (Name == "RIGHT") {
-            Value *Str = emitCoercedExpr(Call->getArgs()[0].get(), resolveType("STRING"));
-            Value *Len = emitCoercedExpr(Call->getArgs()[1].get(), resolveType("INTEGER"));
-            if (!Str || !Len) return nullptr;
-            return StrHandler->emitRight(Str, Len);
-        }
-        if (Name == "LEFT") {
-            Value *Str = emitCoercedExpr(Call->getArgs()[0].get(), resolveType("STRING"));
-            Value *Len = emitCoercedExpr(Call->getArgs()[1].get(), resolveType("INTEGER"));
-            if (!Str || !Len) return nullptr;
-            return StrHandler->emitLeft(Str, Len);
-        }
-        if (Name == "LCASE") {
-            Value *Str = emitCoercedExpr(Call->getArgs()[0].get(), resolveType("STRING"));
-            if (!Str) return nullptr;
-            return StrHandler->emitLCase(Str);
-        }
-        if (Name == "UCASE") {
-            Value *Str = emitCoercedExpr(Call->getArgs()[0].get(), resolveType("STRING"));
-            if (!Str) return nullptr;
-            return StrHandler->emitUCase(Str);
-        }
-        if (Name == "ASC") {
-            const TypeInfo *ArgType = getExprTypeInfo(Call->getArgs()[0].get());
-            if (ArgType && (ArgType->isUserKind() || ArgType->isC())) {
-                reportError("ASC expects a CHAR or STRING (got %s)", ArgType->Name.c_str());
-                return nullptr;
-            }
-            Value *ArgVal = emitExpr(Call->getArgs()[0].get());
-            if (!ArgVal) return nullptr;
-            Value *CharVal = nullptr;
-            if (ArgType && ArgType->isChar()) {
-                CharVal = coerceValueToType(ArgVal, resolveType("CHAR"));
-            } else {
-                CharVal = Builder->CreateLoad(Type::getInt8Ty(*TheContext), ArgVal, "char_load");
-            }
-            Value *AscVal = Builder->CreateZExt(CharVal, Type::getInt32Ty(*TheContext), "asc_val");
-            return coerceValueToType(AscVal, resolveType("INTEGER"));
-        }
-        if (Name == "CHR") {
-            Value *IntVal = emitCoercedExpr(Call->getArgs()[0].get(), resolveType("INTEGER"));
-            if (!IntVal) return nullptr;
-            Value *CharVal = Builder->CreateTrunc(IntVal, Type::getInt8Ty(*TheContext), "chr_val");
-            return coerceValueToType(CharVal, resolveType("STRING"));
-        }
-        if (Name == "IS_NUM") {
-            Value *Str = emitCoercedExpr(Call->getArgs()[0].get(), resolveType("STRING"));
-            if (!Str) return nullptr;
-            return StrConvHandler->emitIsNum(Str);
-        }
-        if (Name == "NUM_TO_STR") {
-            const TypeInfo *ArgType = getExprTypeInfo(Call->getArgs()[0].get());
-            if (ArgType && (ArgType->isUserKind() || ArgType->isC())) {
-                reportError("NUM_TO_STR expects a number (got %s)", ArgType->Name.c_str());
-                return nullptr;
-            }
-            Value *NumV = emitExpr(Call->getArgs()[0].get());
-            if (!NumV) return nullptr;
-            bool IsReal = NumV->getType()->isDoubleTy();
-            if (NumV->getType()->isIntegerTy(8)) {
-                NumV = coerceValueToType(NumV, resolveType("INTEGER"));
-            }
-            return StrConvHandler->emitNumToStr(NumV, IsReal);
-        }
-        if (Name == "STR_TO_NUM") {
-            Value *Str = emitCoercedExpr(Call->getArgs()[0].get(), resolveType("STRING"));
-            if (!Str) return nullptr;
-            return StrConvHandler->emitStrToNum(Str, true);
-        }
-        if (Name == "EOF") {
-            if (isWholeArrayVar(Call->getArgs()[0].get())) {
-                reportError("Cannot use a whole array as the EOF filename");
-                return nullptr;
-            }
-            Value *FileName = emitCoercedExpr(Call->getArgs()[0].get(), resolveType("STRING"));
-            if (!FileName) return nullptr;
-            return Files->emitEof(FileName, Call->getLine());
-        }
-
-        std::vector<Value*> Args;
-        if (!marshalCallArgs(Name, Call->getArgs(), Call->getLine(), Args)) return nullptr;
-        return FuncGen->emitCallExpr(Call, Args);
-    }
-
-    if (auto *D = dynamic_cast<DesignatorExprAST*>(Expr)) {
-        LValueInfo LV;
-        if (!emitLValue(D, LV)) return nullptr;
-        return loadFromLValue(LV);
-    }
-
-    // ^x produces a raw address; it is only admissible where a pointer type
-    // is expected, which emitCoercedExpr enforces by pointee name.
-    if (auto *Addr = dynamic_cast<AddrOfExprAST*>(Expr)) {
-        LValueInfo LV;
-        if (!emitLValue(Addr->getTarget(), LV)) return nullptr;
-        return LV.Addr;
-    }
-
-    return nullptr;
-}
-
 // Collects the arguments for a call to a user FUNCTION/PROCEDURE, dispatching
 // on the *declared* signature: BYREF parameters take the variable's alloca,
 // BYVAL parameters are evaluated and coerced to the declared parameter type.
@@ -912,445 +259,3 @@ bool CodeGen::marshalCallArgs(const std::string &Callee,
     }
     return true;
 }
-
-void CodeGen::emitTryStmt(TryStmtAST *Stmt) {
-    auto *F = Builder->GetInsertBlock()->getParent();
-    auto *CatchBB = BasicBlock::Create(*TheContext, "catch", F);
-    auto *AfterBB = BasicBlock::Create(*TheContext, "try_cont", F);
-    auto SavedArrays = Arrays->snapshotTable();
-
-    Exceptions->pushHandler(CatchBB);
-    for (const auto &S : Stmt->getBody()) emitStmt(S.get());
-    auto *Exception = Exceptions->popHandler();
-    if (!Builder->GetInsertBlock()->hasTerminator()) Builder->CreateBr(AfterBB);
-    Arrays->exchangeTable(SavedArrays);
-
-    Builder->SetInsertPoint(CatchBB);
-    Exceptions->beginCatch(Exception);
-    for (const auto &S : Stmt->getCatchBody()) emitStmt(S.get());
-    Exceptions->endCatch();
-    if (!Builder->GetInsertBlock()->hasTerminator()) Builder->CreateBr(AfterBB);
-    Arrays->exchangeTable(std::move(SavedArrays));
-    Builder->SetInsertPoint(AfterBB);
-}
-
-void CodeGen::emitIfStmt(IfStmtAST *Stmt) {
-    Value *CondV = emitCoercedExpr(Stmt->getCond(), resolveType("BOOLEAN"));
-    if (!CondV) return;
-
-    Function *TheFunction = Builder->GetInsertBlock()->getParent();
-    BasicBlock *ThenBB = BasicBlock::Create(*TheContext, "then", TheFunction);
-    BasicBlock *ElseBB = BasicBlock::Create(*TheContext, "else", TheFunction);
-    BasicBlock *MergeBB = BasicBlock::Create(*TheContext, "ifcont", TheFunction);
-
-    Builder->CreateCondBr(CondV, ThenBB, ElseBB);
-
-    // Arrays are block-scoped: metadata SSA values and the buffer setup live
-    // inside the branch, so a declaration must not survive it.
-    auto SavedArrays = Arrays->snapshotTable();
-    Builder->SetInsertPoint(ThenBB);
-    for (const auto &S : Stmt->getThenStmts()) emitStmt(S.get());
-    if (!Builder->GetInsertBlock()->hasTerminator()) Builder->CreateBr(MergeBB);
-    Arrays->exchangeTable(SavedArrays);
-
-    Builder->SetInsertPoint(ElseBB);
-    for (const auto &S : Stmt->getElseStmts()) emitStmt(S.get());
-    if (!Builder->GetInsertBlock()->hasTerminator()) Builder->CreateBr(MergeBB);
-    Arrays->exchangeTable(std::move(SavedArrays));
-
-    Builder->SetInsertPoint(MergeBB);
-}
-
-void CodeGen::emitWhileStmt(WhileStmtAST *Stmt) {
-    Function *TheFunction = Builder->GetInsertBlock()->getParent();
-
-    BasicBlock *CondBB = BasicBlock::Create(*TheContext, "whilecond", TheFunction);
-    BasicBlock *LoopBB = BasicBlock::Create(*TheContext, "whileloop", TheFunction);
-    BasicBlock *AfterBB = BasicBlock::Create(*TheContext, "whilecont", TheFunction);
-
-    Builder->CreateBr(CondBB);
-
-    Builder->SetInsertPoint(CondBB);
-    Value *CondV = emitCoercedExpr(Stmt->getCond(), resolveType("BOOLEAN"));
-    if (!CondV) return;
-
-    Builder->CreateCondBr(CondV, LoopBB, AfterBB);
-
-    // Arrays declared in the body are block-scoped (see emitIfStmt).
-    auto SavedArrays = Arrays->snapshotTable();
-    Builder->SetInsertPoint(LoopBB);
-    for (const auto &S : Stmt->getBody()) emitStmt(S.get());
-    Arrays->exchangeTable(std::move(SavedArrays));
-
-    if (!Builder->GetInsertBlock()->hasTerminator())
-        Builder->CreateBr(CondBB);
-
-    Builder->SetInsertPoint(AfterBB);
-}
-
-void CodeGen::emitRepeatStmt(RepeatStmtAST *Stmt) {
-    Function *TheFunction = Builder->GetInsertBlock()->getParent();
-
-    BasicBlock *LoopBB = BasicBlock::Create(*TheContext, "repeatloop", TheFunction);
-    BasicBlock *CondBB = BasicBlock::Create(*TheContext, "repeatcond", TheFunction);
-    BasicBlock *AfterBB = BasicBlock::Create(*TheContext, "repeatcont", TheFunction);
-
-    Builder->CreateBr(LoopBB);
-
-    // Arrays declared in the body are block-scoped (see emitIfStmt).
-    auto SavedArrays = Arrays->snapshotTable();
-    Builder->SetInsertPoint(LoopBB);
-    for (const auto &S : Stmt->getBody()) emitStmt(S.get());
-    Arrays->exchangeTable(std::move(SavedArrays));
-    if (!Builder->GetInsertBlock()->hasTerminator())
-        Builder->CreateBr(CondBB);
-
-    Builder->SetInsertPoint(CondBB);
-    Value *CondV = emitCoercedExpr(Stmt->getCond(), resolveType("BOOLEAN"));
-    if (!CondV) return;
-
-    Builder->CreateCondBr(CondV, AfterBB, LoopBB);
-
-    Builder->SetInsertPoint(AfterBB);
-}
-
-void CodeGen::emitForStmt(ForStmtAST *Stmt) {
-    Function *TheFunction = Builder->GetInsertBlock()->getParent();
-    std::string VarName = Stmt->getVarName();
-
-    const SymbolInfo *Symbol = getSymbolInfo(VarName);
-    if (!Symbol) {
-        reportError("Unknown variable in FOR loop %s", VarName.c_str());
-        return;
-    }
-    if (Symbol->TypeName != "INTEGER") {
-        reportError("FOR loop variable %s must be INTEGER", VarName.c_str());
-        return;
-    }
-
-    Value *StartVal = emitCoercedExpr(Stmt->getStart(), resolveType("INTEGER"));
-    if (!StartVal) return;
-
-    Value *Alloca = Symbol->Storage;
-    Builder->CreateStore(StartVal, Alloca);
-
-    // STEP is evaluated exactly once, before the loop.
-    Value *StepVal = nullptr;
-    if (Stmt->getStep()) {
-        StepVal = emitCoercedExpr(Stmt->getStep(), resolveType("INTEGER"));
-        if (!StepVal) return;
-    } else {
-        StepVal = ConstantInt::get(*TheContext, APInt(64, 1));
-    }
-
-    BasicBlock *CondBB = BasicBlock::Create(*TheContext, "forcond", TheFunction);
-    BasicBlock *LoopBB = BasicBlock::Create(*TheContext, "forloop", TheFunction);
-    BasicBlock *IncBB = BasicBlock::Create(*TheContext, "forinc", TheFunction);
-    BasicBlock *AfterBB = BasicBlock::Create(*TheContext, "forcont", TheFunction);
-
-    Builder->CreateBr(CondBB);
-    Builder->SetInsertPoint(CondBB);
-
-    Value *CurVar = Builder->CreateLoad(Type::getInt64Ty(*TheContext), Alloca, VarName.c_str());
-    Value *EndVal = emitCoercedExpr(Stmt->getEnd(), resolveType("INTEGER"));
-    if (!EndVal) return;
-
-    // The loop direction depends on the STEP value at run time.
-    Value *StepNonNeg = Builder->CreateICmpSGE(StepVal,
-                                               ConstantInt::get(*TheContext, APInt(64, 0)),
-                                               "step_nonneg");
-    Value *CondUp = Builder->CreateICmpSLE(CurVar, EndVal, "forcond_le");
-    Value *CondDown = Builder->CreateICmpSGE(CurVar, EndVal, "forcond_ge");
-    Value *CondV = Builder->CreateSelect(StepNonNeg, CondUp, CondDown, "forcond");
-
-    Builder->CreateCondBr(CondV, LoopBB, AfterBB);
-
-    // Arrays declared in the body are block-scoped (see emitIfStmt).
-    auto SavedArrays = Arrays->snapshotTable();
-    Builder->SetInsertPoint(LoopBB);
-    for (const auto &S : Stmt->getBody()) emitStmt(S.get());
-    Arrays->exchangeTable(std::move(SavedArrays));
-    if (!Builder->GetInsertBlock()->hasTerminator())
-        Builder->CreateBr(IncBB);
-
-    Builder->SetInsertPoint(IncBB);
-    Value *CurValForInc = Builder->CreateLoad(Type::getInt64Ty(*TheContext), Alloca, VarName.c_str());
-    Value *NextVal = Builder->CreateAdd(CurValForInc, StepVal, "nextval");
-    Builder->CreateStore(NextVal, Alloca);
-    Builder->CreateBr(CondBB);
-
-    Builder->SetInsertPoint(AfterBB);
-}
-
-void CodeGen::emitStmt(StmtAST *Stmt) {
-    if (!Stmt) return;
-
-    if (auto *FuncDef = dynamic_cast<FunctionDefAST*>(Stmt)) {
-        BasicBlock *SavedBlock = Builder->GetInsertBlock();
-        // Function bodies get a fresh array scope (metadata SSA values belong
-        // to the emitting function), mirroring FunctionGen's Symbols handling.
-        auto SavedArrays = Arrays->exchangeTable({});
-
-        FuncGen->emitFunctionDef(FuncDef, [this](StmtAST *S) {
-            this->emitStmt(S);
-        });
-
-        Arrays->exchangeTable(std::move(SavedArrays));
-        if (SavedBlock) Builder->SetInsertPoint(SavedBlock);
-        return;
-    }
-
-    // Keep diagnosing statements after RETURN/THROW without appending code
-    // to a terminated block or making those statements reachable.
-    if (Builder->GetInsertBlock()->hasTerminator()) {
-        auto *F = Builder->GetInsertBlock()->getParent();
-        Builder->SetInsertPoint(BasicBlock::Create(*TheContext, "unreachable_code", F));
-    }
-
-    if (auto *Try = dynamic_cast<TryStmtAST*>(Stmt)) {
-        emitTryStmt(Try);
-        return;
-    }
-    if (dynamic_cast<ThrowStmtAST*>(Stmt)) {
-        Exceptions->emitThrow();
-        return;
-    }
-    if (auto *ArrDecl = dynamic_cast<ArrayDeclareStmtAST*>(Stmt)) {
-        Arrays->emitArrayDeclare(ArrDecl, *this);
-        return;
-    }
-    if (auto *ArrAssign = dynamic_cast<ArrayAssignStmtAST*>(Stmt)) {
-        Arrays->emitArrayAssign(ArrAssign, *this);
-        return;
-    }
-
-    if (auto *Call = dynamic_cast<CallStmtAST*>(Stmt)) {
-        std::vector<Value*> Args;
-        if (!marshalCallArgs(Call->getCallee(), Call->getArgs(), Call->getLine(), Args)) return;
-        FuncGen->emitCallStmt(Call, Args);
-        return;
-    }
-
-    if (auto *Ret = dynamic_cast<ReturnStmtAST*>(Stmt)) {
-        Function *F = Builder->GetInsertBlock()->getParent();
-        const FuncSig *Sig = FuncGen->getSignature(F->getName().str());
-        // Pseudocode cannot name a function "main" (reserved runtime symbol),
-        // so no signature means we are emitting the top level.
-        if (!Sig) {
-            reportError("RETURN is only allowed inside a FUNCTION or PROCEDURE");
-            return;
-        }
-        if (F->getReturnType()->isVoidTy() && Ret->getRetVal()) {
-            reportError("RETURN with a value is only allowed in a FUNCTION");
-            return;
-        }
-        if (!F->getReturnType()->isVoidTy() && !Ret->getRetVal()) {
-            reportError("RETURN in a FUNCTION requires a value");
-            return;
-        }
-        Value *RetVal = nullptr;
-        if (Ret->getRetVal()) {
-            RetVal = emitCoercedExpr(Ret->getRetVal(), resolveType(Sig->ReturnTypeName));
-            if (!RetVal) return;
-        }
-        FuncGen->emitReturn(Ret, RetVal);
-        return;
-    }
-
-    if (auto *Decl = dynamic_cast<DeclareStmtAST*>(Stmt)) {
-        emitDeclareStmt(Decl);
-        return;
-    }
-
-    if (auto *Assign = dynamic_cast<AssignStmtAST*>(Stmt)) {
-        const SymbolInfo *Info = getSymbolInfo(Assign->getName());
-        if (!Info) {
-            if (Types->lookupEnumConstant(Assign->getName())) {
-                reportError("Enum value %s is not an assignable location", Assign->getName().c_str());
-            } else {
-                reportError("Unknown variable name %s", Assign->getName().c_str());
-            }
-            return;
-        }
-        if (Info->IsArray) {
-            reportError("Cannot assign array %s without indices", Assign->getName().c_str());
-            return;
-        }
-
-        Value *Val = emitCoercedExpr(Assign->getExpr(), resolveType(Info->TypeName));
-        if (!Val) return;
-
-        Builder->CreateStore(Val, Info->Storage);
-        return;
-    }
-
-    if (auto *In = dynamic_cast<InputStmtAST*>(Stmt)) {
-        const SymbolInfo *Info = getSymbolInfo(In->getName());
-        if (!Info) {
-            reportError("Unknown variable name %s", In->getName().c_str());
-            return;
-        }
-        if (Info->IsArray) {
-            reportError("INPUT for entire array %s is not supported", In->getName().c_str());
-            return;
-        }
-
-        const TypeInfo *TypeInfo = resolveType(Info->TypeName);
-        if (!TypeInfo) {
-            reportError("Unknown type for INPUT %s", In->getName().c_str());
-            return;
-        }
-
-        std::vector<Value*> Args;
-        if (TypeInfo->isC()) {
-            emitCInput(Info, TypeInfo);
-        } else if (TypeInfo->isReal()) {
-            Args.push_back(ScanfFloatFormatStr);
-            Args.push_back(Info->Storage);
-            Builder->CreateCall(ScanfFunc, Args);
-        } else if (TypeInfo->isBoolean()) {
-            AllocaInst *TempInt = CreateEntryBlockAlloca(Builder->GetInsertBlock()->getParent(), "tmp_bool_input");
-            Args.push_back(ScanfFormatStr);
-            Args.push_back(TempInt);
-            Builder->CreateCall(ScanfFunc, Args);
-
-            Value *Val = Builder->CreateLoad(Type::getInt64Ty(*TheContext), TempInt);
-            Value *BoolVal = Builder->CreateICmpNE(Val, ConstantInt::get(*TheContext, APInt(64, 0)), "bool_cast");
-            Builder->CreateStore(BoolVal, Info->Storage);
-        } else if (TypeInfo->isString()) {
-            Value *Mem = Builder->CreateCall(MallocFunc, ConstantInt::get(*TheContext, APInt(64, 1024)), "input_str");
-            Args.push_back(ScanfStringFormatStr);
-            Args.push_back(Mem);
-            Builder->CreateCall(ScanfFunc, Args);
-            Builder->CreateStore(Mem, Info->Storage);
-        } else if (TypeInfo->isChar()) {
-            Value *CharFmt = Builder->CreateGlobalString(" %c", "fmt_in_char", 0, TheModule.get());
-            Args.push_back(CharFmt);
-            Args.push_back(Info->Storage);
-            Builder->CreateCall(ScanfFunc, Args);
-        } else if (TypeInfo->Kind == TypeKind::Integer) {
-            Args.push_back(ScanfFormatStr);
-            Args.push_back(Info->Storage);
-            Builder->CreateCall(ScanfFunc, Args);
-        } else {
-            // Enum/Record/Pointer and any future kind: scanf'ing raw bytes
-            // into typed storage would corrupt it — reject explicitly.
-            reportError("INPUT is not supported for a value of type %s", TypeInfo->Name.c_str());
-        }
-        return;
-    }
-
-    if (auto *Out = dynamic_cast<OutputStmtAST*>(Stmt)) {
-        const auto &Exprs = Out->getExprs();
-        for (size_t I = 0; I < Exprs.size(); ++I) {
-            ExprAST *Expr = Exprs[I].get();
-            if (Arrays->tryEmitArrayOutput(Expr, *this)) continue;
-
-            Value *Val = emitExpr(Expr);
-            const TypeInfo *TypeInfo = getExprTypeInfo(Expr);
-            if (!TypeInfo) {
-                reportError("Cannot infer the type of the OUTPUT expression");
-                continue;
-            }
-            if (TypeInfo->isVoid()) {
-                reportError("Cannot OUTPUT the result of a PROCEDURE call");
-                continue;
-            }
-            emitOutputValue(Val, TypeInfo, I + 1 == Exprs.size());
-        }
-        return;
-    }
-
-    if (auto *Open = dynamic_cast<OpenFileStmtAST*>(Stmt)) {
-        if (isWholeArrayVar(Open->getFileName())) {
-            reportError("Cannot use a whole array as the OPENFILE filename");
-            return;
-        }
-        Value *Name = emitCoercedExpr(Open->getFileName(), resolveType("STRING"));
-        if (!Name) return;
-        Files->emitOpen(Name, Open->getMode(), Open->getLine());
-        return;
-    }
-
-    if (auto *Read = dynamic_cast<ReadFileStmtAST*>(Stmt)) {
-        const SymbolInfo *Info = getSymbolInfo(Read->getVarName());
-        if (!Info) {
-            reportError("Unknown variable name %s", Read->getVarName().c_str());
-            return;
-        }
-        if (Info->IsArray) {
-            reportError("READFILE into entire array %s is not supported", Read->getVarName().c_str());
-            return;
-        }
-        if (Info->TypeName != "STRING") {
-            reportError("READFILE variable %s must be of type STRING (got %s)",
-                        Read->getVarName().c_str(), Info->TypeName.c_str());
-            return;
-        }
-        if (isWholeArrayVar(Read->getFileName())) {
-            reportError("Cannot use a whole array as the READFILE filename");
-            return;
-        }
-        Value *Name = emitCoercedExpr(Read->getFileName(), resolveType("STRING"));
-        if (!Name) return;
-        Value *LineStr = Files->emitRead(Name, Read->getLine());
-        if (!LineStr) return;
-        Builder->CreateStore(LineStr, Info->Storage);
-        return;
-    }
-
-    if (auto *Write = dynamic_cast<WriteFileStmtAST*>(Stmt)) {
-        if (isWholeArrayVar(Write->getFileName()) || isWholeArrayVar(Write->getData())) {
-            reportError("Cannot use a whole array in WRITEFILE");
-            return;
-        }
-        Value *Name = emitCoercedExpr(Write->getFileName(), resolveType("STRING"));
-        Value *Data = emitCoercedExpr(Write->getData(), resolveType("STRING"));
-        if (!Name || !Data) return;
-        Files->emitWrite(Name, Data, Write->getLine());
-        return;
-    }
-
-    if (auto *Close = dynamic_cast<CloseFileStmtAST*>(Stmt)) {
-        if (isWholeArrayVar(Close->getFileName())) {
-            reportError("Cannot use a whole array as the CLOSEFILE filename");
-            return;
-        }
-        Value *Name = emitCoercedExpr(Close->getFileName(), resolveType("STRING"));
-        if (!Name) return;
-        Files->emitClose(Name, Close->getLine());
-        return;
-    }
-
-    if (auto *IfStmt = dynamic_cast<IfStmtAST*>(Stmt)) {
-        emitIfStmt(IfStmt);
-        return;
-    }
-    if (auto *WhileStmt = dynamic_cast<WhileStmtAST*>(Stmt)) {
-        emitWhileStmt(WhileStmt);
-        return;
-    }
-    if (auto *RepeatStmt = dynamic_cast<RepeatStmtAST*>(Stmt)) {
-        emitRepeatStmt(RepeatStmt);
-        return;
-    }
-    if (auto *ForStmt = dynamic_cast<ForStmtAST*>(Stmt)) {
-        emitForStmt(ForStmt);
-        return;
-    }
-
-    // TYPE declarations are registered by compile()'s pre-pass (the parser
-    // guarantees they are top-level); nothing is emitted here.
-    if (dynamic_cast<EnumTypeDeclAST*>(Stmt) || dynamic_cast<PointerTypeDeclAST*>(Stmt) ||
-        dynamic_cast<RecordTypeDeclAST*>(Stmt) || dynamic_cast<CTypeDeclAST*>(Stmt)) {
-        return;
-    }
-    if (auto *DA = dynamic_cast<DesignatorAssignStmtAST*>(Stmt)) {
-        LValueInfo LV;
-        if (!emitLValue(DA->getTarget(), LV)) return;
-        Value *Val = emitCoercedExpr(DA->getExpr(), resolveType(LV.TypeName));
-        if (!Val) return;
-        Builder->CreateStore(Val, LV.Addr);
-        return;
-    }
-}
diff --git a/lib/CodeGen/ControlFlowGen.cc b/lib/CodeGen/ControlFlowGen.cc
new file mode 100644
index 0000000..ebd5d3c
--- /dev/null
+++ b/lib/CodeGen/ControlFlowGen.cc
@@ -0,0 +1,175 @@
+#include "cps/CodeGen.h"
+#include "cps/ArrayHandler.h"
+#include "cps/ExceptionHandler.h"
+
+using namespace llvm;
+using namespace cps;
+
+void CodeGen::emitTryStmt(TryStmtAST *Stmt) {
+    auto *F = Builder->GetInsertBlock()->getParent();
+    auto *CatchBB = BasicBlock::Create(*TheContext, "catch", F);
+    auto *AfterBB = BasicBlock::Create(*TheContext, "try_cont", F);
+    auto SavedArrays = Arrays->snapshotTable();
+
+    Exceptions->pushHandler(CatchBB);
+    for (const auto &S : Stmt->getBody()) emitStmt(S.get());
+    auto *Exception = Exceptions->popHandler();
+    if (!Builder->GetInsertBlock()->hasTerminator()) Builder->CreateBr(AfterBB);
+    Arrays->exchangeTable(SavedArrays);
+
+    Builder->SetInsertPoint(CatchBB);
+    Exceptions->beginCatch(Exception);
+    for (const auto &S : Stmt->getCatchBody()) emitStmt(S.get());
+    Exceptions->endCatch();
+    if (!Builder->GetInsertBlock()->hasTerminator()) Builder->CreateBr(AfterBB);
+    Arrays->exchangeTable(std::move(SavedArrays));
+    Builder->SetInsertPoint(AfterBB);
+}
+
+void CodeGen::emitIfStmt(IfStmtAST *Stmt) {
+    Value *CondV = emitCoercedExpr(Stmt->getCond(), resolveType("BOOLEAN"));
+    if (!CondV) return;
+
+    Function *TheFunction = Builder->GetInsertBlock()->getParent();
+    BasicBlock *ThenBB = BasicBlock::Create(*TheContext, "then", TheFunction);
+    BasicBlock *ElseBB = BasicBlock::Create(*TheContext, "else", TheFunction);
+    BasicBlock *MergeBB = BasicBlock::Create(*TheContext, "ifcont", TheFunction);
+
+    Builder->CreateCondBr(CondV, ThenBB, ElseBB);
+
+    // Arrays are block-scoped: metadata SSA values and the buffer setup live
+    // inside the branch, so a declaration must not survive it.
+    auto SavedArrays = Arrays->snapshotTable();
+    Builder->SetInsertPoint(ThenBB);
+    for (const auto &S : Stmt->getThenStmts()) emitStmt(S.get());
+    if (!Builder->GetInsertBlock()->hasTerminator()) Builder->CreateBr(MergeBB);
+    Arrays->exchangeTable(SavedArrays);
+
+    Builder->SetInsertPoint(ElseBB);
+    for (const auto &S : Stmt->getElseStmts()) emitStmt(S.get());
+    if (!Builder->GetInsertBlock()->hasTerminator()) Builder->CreateBr(MergeBB);
+    Arrays->exchangeTable(std::move(SavedArrays));
+
+    Builder->SetInsertPoint(MergeBB);
+}
+
+void CodeGen::emitWhileStmt(WhileStmtAST *Stmt) {
+    Function *TheFunction = Builder->GetInsertBlock()->getParent();
+
+    BasicBlock *CondBB = BasicBlock::Create(*TheContext, "whilecond", TheFunction);
+    BasicBlock *LoopBB = BasicBlock::Create(*TheContext, "whileloop", TheFunction);
+    BasicBlock *AfterBB = BasicBlock::Create(*TheContext, "whilecont", TheFunction);
+
+    Builder->CreateBr(CondBB);
+
+    Builder->SetInsertPoint(CondBB);
+    Value *CondV = emitCoercedExpr(Stmt->getCond(), resolveType("BOOLEAN"));
+    if (!CondV) return;
+
+    Builder->CreateCondBr(CondV, LoopBB, AfterBB);
+
+    // Arrays declared in the body are block-scoped (see emitIfStmt).
+    auto SavedArrays = Arrays->snapshotTable();
+    Builder->SetInsertPoint(LoopBB);
+    for (const auto &S : Stmt->getBody()) emitStmt(S.get());
+    Arrays->exchangeTable(std::move(SavedArrays));
+
+    if (!Builder->GetInsertBlock()->hasTerminator())
+        Builder->CreateBr(CondBB);
+
+    Builder->SetInsertPoint(AfterBB);
+}
+
+void CodeGen::emitRepeatStmt(RepeatStmtAST *Stmt) {
+    Function *TheFunction = Builder->GetInsertBlock()->getParent();
+
+    BasicBlock *LoopBB = BasicBlock::Create(*TheContext, "repeatloop", TheFunction);
+    BasicBlock *CondBB = BasicBlock::Create(*TheContext, "repeatcond", TheFunction);
+    BasicBlock *AfterBB = BasicBlock::Create(*TheContext, "repeatcont", TheFunction);
+
+    Builder->CreateBr(LoopBB);
+
+    // Arrays declared in the body are block-scoped (see emitIfStmt).
+    auto SavedArrays = Arrays->snapshotTable();
+    Builder->SetInsertPoint(LoopBB);
+    for (const auto &S : Stmt->getBody()) emitStmt(S.get());
+    Arrays->exchangeTable(std::move(SavedArrays));
+    if (!Builder->GetInsertBlock()->hasTerminator())
+        Builder->CreateBr(CondBB);
+
+    Builder->SetInsertPoint(CondBB);
+    Value *CondV = emitCoercedExpr(Stmt->getCond(), resolveType("BOOLEAN"));
+    if (!CondV) return;
+
+    Builder->CreateCondBr(CondV, AfterBB, LoopBB);
+
+    Builder->SetInsertPoint(AfterBB);
+}
+
+void CodeGen::emitForStmt(ForStmtAST *Stmt) {
+    Function *TheFunction = Builder->GetInsertBlock()->getParent();
+    std::string VarName = Stmt->getVarName();
+
+    const SymbolInfo *Symbol = getSymbolInfo(VarName);
+    if (!Symbol) {
+        reportError("Unknown variable in FOR loop %s", VarName.c_str());
+        return;
+    }
+    if (Symbol->TypeName != "INTEGER") {
+        reportError("FOR loop variable %s must be INTEGER", VarName.c_str());
+        return;
+    }
+
+    Value *StartVal = emitCoercedExpr(Stmt->getStart(), resolveType("INTEGER"));
+    if (!StartVal) return;
+
+    Value *Alloca = Symbol->Storage;
+    Builder->CreateStore(StartVal, Alloca);
+
+    // STEP is evaluated exactly once, before the loop.
+    Value *StepVal = nullptr;
+    if (Stmt->getStep()) {
+        StepVal = emitCoercedExpr(Stmt->getStep(), resolveType("INTEGER"));
+        if (!StepVal) return;
+    } else {
+        StepVal = ConstantInt::get(*TheContext, APInt(64, 1));
+    }
+
+    BasicBlock *CondBB = BasicBlock::Create(*TheContext, "forcond", TheFunction);
+    BasicBlock *LoopBB = BasicBlock::Create(*TheContext, "forloop", TheFunction);
+    BasicBlock *IncBB = BasicBlock::Create(*TheContext, "forinc", TheFunction);
+    BasicBlock *AfterBB = BasicBlock::Create(*TheContext, "forcont", TheFunction);
+
+    Builder->CreateBr(CondBB);
+    Builder->SetInsertPoint(CondBB);
+
+    Value *CurVar = Builder->CreateLoad(Type::getInt64Ty(*TheContext), Alloca, VarName.c_str());
+    Value *EndVal = emitCoercedExpr(Stmt->getEnd(), resolveType("INTEGER"));
+    if (!EndVal) return;
+
+    // The loop direction depends on the STEP value at run time.
+    Value *StepNonNeg = Builder->CreateICmpSGE(StepVal,
+                                               ConstantInt::get(*TheContext, APInt(64, 0)),
+                                               "step_nonneg");
+    Value *CondUp = Builder->CreateICmpSLE(CurVar, EndVal, "forcond_le");
+    Value *CondDown = Builder->CreateICmpSGE(CurVar, EndVal, "forcond_ge");
+    Value *CondV = Builder->CreateSelect(StepNonNeg, CondUp, CondDown, "forcond");
+
+    Builder->CreateCondBr(CondV, LoopBB, AfterBB);
+
+    // Arrays declared in the body are block-scoped (see emitIfStmt).
+    auto SavedArrays = Arrays->snapshotTable();
+    Builder->SetInsertPoint(LoopBB);
+    for (const auto &S : Stmt->getBody()) emitStmt(S.get());
+    Arrays->exchangeTable(std::move(SavedArrays));
+    if (!Builder->GetInsertBlock()->hasTerminator())
+        Builder->CreateBr(IncBB);
+
+    Builder->SetInsertPoint(IncBB);
+    Value *CurValForInc = Builder->CreateLoad(Type::getInt64Ty(*TheContext), Alloca, VarName.c_str());
+    Value *NextVal = Builder->CreateAdd(CurValForInc, StepVal, "nextval");
+    Builder->CreateStore(NextVal, Alloca);
+    Builder->CreateBr(CondBB);
+
+    Builder->SetInsertPoint(AfterBB);
+}
diff --git a/lib/CodeGen/ExpressionGen.cc b/lib/CodeGen/ExpressionGen.cc
new file mode 100644
index 0000000..0d69408
--- /dev/null
+++ b/lib/CodeGen/ExpressionGen.cc
@@ -0,0 +1,273 @@
+#include "cps/CodeGen.h"
+#include "cps/ArrayHandler.h"
+#include "cps/FileHandler.h"
+#include "cps/Lexer.h"
+#include "cps/TypeAST.h"
+#include "Builtins.h"
+
+using namespace llvm;
+using namespace cps;
+
+using namespace cps::detail;
+
+Value *CodeGen::emitExpr(ExprAST *Expr) {
+    if (auto *Cast = dynamic_cast<CastExprAST*>(Expr)) return emitCast(Cast);
+    if (!Expr) return nullptr;
+
+    if (auto *Num = dynamic_cast<IntegerExprAST*>(Expr)) {
+        return ConstantInt::get(*TheContext, APInt(64, Num->getVal(), true));
+    }
+
+    if (auto *Real = dynamic_cast<RealExprAST*>(Expr)) {
+        return ConstantFP::get(*TheContext, APFloat(Real->getVal()));
+    }
+
+    if (auto *Bool = dynamic_cast<BooleanExprAST*>(Expr)) {
+        return ConstantInt::get(*TheContext, APInt(1, Bool->getVal() ? 1 : 0));
+    }
+
+    if (auto *Chr = dynamic_cast<CharExprAST*>(Expr)) {
+        return ConstantInt::get(Type::getInt8Ty(*TheContext), static_cast<unsigned char>(Chr->getVal()));
+    }
+
+    if (auto *Str = dynamic_cast<StringExprAST*>(Expr)) {
+        return StrHandler->createLiteral(Str->getVal());
+    }
+
+    if (auto *Var = dynamic_cast<VariableExprAST*>(Expr)) {
+        const SymbolInfo *Info = getSymbolInfo(Var->getName());
+        if (!Info) {
+            // Enum values are bare identifiers; collisions with variables are
+            // rejected at declaration time, so the order here cannot shadow.
+            if (const EnumConstant *EC = Types->lookupEnumConstant(Var->getName())) {
+                return ConstantInt::get(*TheContext, APInt(64, static_cast<uint64_t>(EC->Ordinal), true));
+            }
+            reportError("Unknown variable name %s", Var->getName().c_str());
+            return nullptr;
+        }
+        if (Info->IsArray) {
+            return Info->Storage;
+        }
+
+        const TypeInfo *TypeInfo = resolveType(Info->TypeName);
+        if (!TypeInfo || !TypeInfo->LLVMType) {
+            reportError("Unknown type for variable %s", Var->getName().c_str());
+            return nullptr;
+        }
+
+        Value *Loaded = Builder->CreateLoad(TypeInfo->LLVMType, Info->Storage, Var->getName().c_str());
+        if (TypeInfo->isString()) {
+            Loaded = emitStringNullGuard(Loaded);
+        }
+        return Loaded;
+    }
+
+    if (auto *ArrAcc = dynamic_cast<ArrayAccessExprAST*>(Expr)) {
+        return Arrays->emitArrayAccess(ArrAcc, *this);
+    }
+
+    if (auto *Unary = dynamic_cast<UnaryExprAST*>(Expr)) {
+        if (Unary->getOp() == tok_not) {
+            const TypeInfo *Info = getExprTypeInfo(Unary->getOperand());
+            Value *Operand = Info && Info->isC()
+                ? convertNumericValue(emitExpr(Unary->getOperand()), Info, resolveType("BOOLEAN"))
+                : emitCoercedExpr(Unary->getOperand(), resolveType("BOOLEAN"));
+            if (Info && Info->Kind == TypeKind::CPointer) {
+                reportError("NOT does not support C pointer operands");
+                return nullptr;
+            }
+            if (!Operand) return nullptr;
+            return Builder->CreateNot(Operand, "nottmp");
+        }
+        if (Unary->getOp() == '-') {
+            const TypeInfo *Info = getExprTypeInfo(Unary->getOperand());
+            if (Info && Info->Kind == TypeKind::CScalar && !Info->isVoid()) {
+                const TypeInfo *Promoted = Types->promoteCScalar(Info);
+                Value *Operand = convertNumericValue(emitExpr(Unary->getOperand()), Info, Promoted);
+                if (!Operand) return nullptr;
+                return Promoted->isReal() ? Builder->CreateFNeg(Operand, "c_neg")
+                                          : Builder->CreateNeg(Operand, "c_neg");
+            }
+            if (!Info || Info->isC() || Info->isUserKind() || Info->isString() || Info->isVoid()) {
+                reportError("Unary '-' requires a supported numeric operand");
+                return nullptr;
+            }
+            Value *Operand = emitExpr(Unary->getOperand());
+            if (!Operand) return nullptr;
+            return ArithHandler->emitBinaryOp('-', ConstantInt::get(Type::getInt64Ty(*TheContext), 0),
+                                             Operand, 0);
+        }
+        return nullptr;
+    }
+
+    if (auto *Bin = dynamic_cast<BinaryExprAST*>(Expr)) {
+        // Whole arrays evaluate to raw data pointers and ^x to raw addresses;
+        // neither is a value any operator may consume.
+        if (isWholeArrayVar(Bin->getLHS()) || isWholeArrayVar(Bin->getRHS())) {
+            reportError("A whole array cannot be used as an operand; index it");
+            return nullptr;
+        }
+        if (dynamic_cast<AddrOfExprAST*>(Bin->getLHS()) ||
+            dynamic_cast<AddrOfExprAST*>(Bin->getRHS())) {
+            reportError("'^' (address-of) can only be used where a pointer type is expected");
+            return nullptr;
+        }
+
+        // Enum/Record/Pointer operands never reach ArithmeticHandler or the
+        // '&' path: their admissible operations are decided by name here.
+        const TypeInfo *LT = getExprTypeInfo(Bin->getLHS());
+        const TypeInfo *RT = getExprTypeInfo(Bin->getRHS());
+        if ((LT && LT->isC()) || (RT && RT->isC())) {
+            return emitCBinaryOp(Bin, LT, RT);
+        }
+        if ((LT && LT->isUserKind()) || (RT && RT->isUserKind())) {
+            return emitUserKindBinaryOp(Bin, LT, RT);
+        }
+
+        Value *L = emitExpr(Bin->getLHS());
+        Value *R = emitExpr(Bin->getRHS());
+        if (!L || !R) return nullptr;
+        if (Bin->getOp() == '&') {
+            L = coerceValueToType(L, resolveType("STRING"));
+            R = coerceValueToType(R, resolveType("STRING"));
+            if (!L || !R) return nullptr;
+            return StrHandler->emitConcat(L, R);
+        }
+        // STRING and explicit pointers share LLVM's ptr representation;
+        // string comparisons must dispatch on the pseudocode type.
+        switch (Bin->getOp()) {
+        case tok_eq: case tok_ne: case '<': case '>': case tok_le: case tok_ge:
+            if ((LT && LT->isString()) || (RT && RT->isString())) {
+                if (!(LT && LT->isString() && RT && RT->isString())) {
+                    reportError("STRING comparison requires two STRING operands (line %d)", Bin->getLine());
+                    return nullptr;
+                }
+                return StrHandler->emitCompare(Bin->getOp(), L, R);
+            }
+            break;
+        default:
+            break;
+        }
+        return ArithHandler->emitBinaryOp(Bin->getOp(), L, R, Bin->getLine());
+    }
+
+    if (auto *Call = dynamic_cast<CallExprAST*>(Expr)) {
+        std::string Name = Call->getCallee();
+        if (const BuiltinInfo *B = findBuiltin(Name)) {
+            if (Call->getArgs().size() != B->Arity) {
+                reportError("%s expects %u arg%s", B->Name, B->Arity, B->Arity == 1 ? "" : "s");
+                return nullptr;
+            }
+        }
+        if (Name == "LENGTH") {
+            Value *Str = emitCoercedExpr(Call->getArgs()[0].get(), resolveType("STRING"));
+            if (!Str) return nullptr;
+            return StrHandler->emitLength(Str);
+        }
+        if (Name == "MID") {
+            Value *Str = emitCoercedExpr(Call->getArgs()[0].get(), resolveType("STRING"));
+            Value *Start = emitCoercedExpr(Call->getArgs()[1].get(), resolveType("INTEGER"));
+            Value *Len = emitCoercedExpr(Call->getArgs()[2].get(), resolveType("INTEGER"));
+            if (!Str || !Start || !Len) return nullptr;
+            return StrHandler->emitMid(Str, Start, Len);
+        }
+        if (Name == "RIGHT") {
+            Value *Str = emitCoercedExpr(Call->getArgs()[0].get(), resolveType("STRING"));
+            Value *Len = emitCoercedExpr(Call->getArgs()[1].get(), resolveType("INTEGER"));
+            if (!Str || !Len) return nullptr;
+            return StrHandler->emitRight(Str, Len);
+        }
+        if (Name == "LEFT") {
+            Value *Str = emitCoercedExpr(Call->getArgs()[0].get(), resolveType("STRING"));
+            Value *Len = emitCoercedExpr(Call->getArgs()[1].get(), resolveType("INTEGER"));
+            if (!Str || !Len) return nullptr;
+            return StrHandler->emitLeft(Str, Len);
+        }
+        if (Name == "LCASE") {
+            Value *Str = emitCoercedExpr(Call->getArgs()[0].get(), resolveType("STRING"));
+            if (!Str) return nullptr;
+            return StrHandler->emitLCase(Str);
+        }
+        if (Name == "UCASE") {
+            Value *Str = emitCoercedExpr(Call->getArgs()[0].get(), resolveType("STRING"));
+            if (!Str) return nullptr;
+            return StrHandler->emitUCase(Str);
+        }
+        if (Name == "ASC") {
+            const TypeInfo *ArgType = getExprTypeInfo(Call->getArgs()[0].get());
+            if (ArgType && (ArgType->isUserKind() || ArgType->isC())) {
+                reportError("ASC expects a CHAR or STRING (got %s)", ArgType->Name.c_str());
+                return nullptr;
+            }
+            Value *ArgVal = emitExpr(Call->getArgs()[0].get());
+            if (!ArgVal) return nullptr;
+            Value *CharVal = nullptr;
+            if (ArgType && ArgType->isChar()) {
+                CharVal = coerceValueToType(ArgVal, resolveType("CHAR"));
+            } else {
+                CharVal = Builder->CreateLoad(Type::getInt8Ty(*TheContext), ArgVal, "char_load");
+            }
+            Value *AscVal = Builder->CreateZExt(CharVal, Type::getInt32Ty(*TheContext), "asc_val");
+            return coerceValueToType(AscVal, resolveType("INTEGER"));
+        }
+        if (Name == "CHR") {
+            Value *IntVal = emitCoercedExpr(Call->getArgs()[0].get(), resolveType("INTEGER"));
+            if (!IntVal) return nullptr;
+            Value *CharVal = Builder->CreateTrunc(IntVal, Type::getInt8Ty(*TheContext), "chr_val");
+            return coerceValueToType(CharVal, resolveType("STRING"));
+        }
+        if (Name == "IS_NUM") {
+            Value *Str = emitCoercedExpr(Call->getArgs()[0].get(), resolveType("STRING"));
+            if (!Str) return nullptr;
+            return StrConvHandler->emitIsNum(Str);
+        }
+        if (Name == "NUM_TO_STR") {
+            const TypeInfo *ArgType = getExprTypeInfo(Call->getArgs()[0].get());
+            if (ArgType && (ArgType->isUserKind() || ArgType->isC())) {
+                reportError("NUM_TO_STR expects a number (got %s)", ArgType->Name.c_str());
+                return nullptr;
+            }
+            Value *NumV = emitExpr(Call->getArgs()[0].get());
+            if (!NumV) return nullptr;
+            bool IsReal = NumV->getType()->isDoubleTy();
+            if (NumV->getType()->isIntegerTy(8)) {
+                NumV = coerceValueToType(NumV, resolveType("INTEGER"));
+            }
+            return StrConvHandler->emitNumToStr(NumV, IsReal);
+        }
+        if (Name == "STR_TO_NUM") {
+            Value *Str = emitCoercedExpr(Call->getArgs()[0].get(), resolveType("STRING"));
+            if (!Str) return nullptr;
+            return StrConvHandler->emitStrToNum(Str, true);
+        }
+        if (Name == "EOF") {
+            if (isWholeArrayVar(Call->getArgs()[0].get())) {
+                reportError("Cannot use a whole array as the EOF filename");
+                return nullptr;
+            }
+            Value *FileName = emitCoercedExpr(Call->getArgs()[0].get(), resolveType("STRING"));
+            if (!FileName) return nullptr;
+            return Files->emitEof(FileName, Call->getLine());
+        }
+
+        std::vector<Value*> Args;
+        if (!marshalCallArgs(Name, Call->getArgs(), Call->getLine(), Args)) return nullptr;
+        return FuncGen->emitCallExpr(Call, Args);
+    }
+
+    if (auto *D = dynamic_cast<DesignatorExprAST*>(Expr)) {
+        LValueInfo LV;
+        if (!emitLValue(D, LV)) return nullptr;
+        return loadFromLValue(LV);
+    }
+
+    // ^x produces a raw address; it is only admissible where a pointer type
+    // is expected, which emitCoercedExpr enforces by pointee name.
+    if (auto *Addr = dynamic_cast<AddrOfExprAST*>(Expr)) {
+        LValueInfo LV;
+        if (!emitLValue(Addr->getTarget(), LV)) return nullptr;
+        return LV.Addr;
+    }
+
+    return nullptr;
+}
diff --git a/lib/CodeGen/OutputGen.cc b/lib/CodeGen/OutputGen.cc
new file mode 100644
index 0000000..c4ceb79
--- /dev/null
+++ b/lib/CodeGen/OutputGen.cc
@@ -0,0 +1,95 @@
+#include "cps/CodeGen.h"
+
+using namespace llvm;
+using namespace cps;
+
+Value *CodeGen::emitStringNullGuard(Value *StrVal) {
+    if (!StrVal || !StrVal->getType()->isPointerTy()) return StrVal;
+    Value *IsNull = Builder->CreateICmpEQ(StrVal,
+                                          ConstantPointerNull::get(cast<PointerType>(StrVal->getType())),
+                                          "str_is_null");
+    return Builder->CreateSelect(IsNull, EmptyStringStr, StrVal, "safe_str");
+}
+
+void CodeGen::emitOutputValue(Value *Val, const TypeInfo *Info, bool AppendNewline) {
+    if (!Val || !Info) return;
+
+    std::vector<Value*> Args;
+    Value *Fmt = nullptr;
+
+    // Exhaustive over TypeKind (no default): the compiler warns when a new
+    // kind is added without deciding its OUTPUT story.
+    switch (Info->Kind) {
+    case TypeKind::Real:
+        Fmt = AppendNewline
+            ? PrintfFloatFormatStr
+            : Builder->CreateGlobalString("%f", "fmt_flt_inline", 0, TheModule.get());
+        Args.push_back(Fmt);
+        Args.push_back(Val);
+        break;
+
+    case TypeKind::Boolean: {
+        Value *BoolVal = coerceValueToType(Val, resolveType("BOOLEAN"));
+        Fmt = AppendNewline
+            ? PrintfStringFormatStr
+            : Builder->CreateGlobalString("%s", "fmt_str_inline", 0, TheModule.get());
+        Args.push_back(Fmt);
+        Args.push_back(Builder->CreateSelect(BoolVal, TrueStr, FalseStr));
+        break;
+    }
+
+    case TypeKind::String: {
+        Value *StrVal = emitStringNullGuard(Val);
+        Fmt = AppendNewline
+            ? PrintfStringFormatStr
+            : Builder->CreateGlobalString("%s", "fmt_str_inline", 0, TheModule.get());
+        Args.push_back(Fmt);
+        Args.push_back(StrVal);
+        break;
+    }
+
+    case TypeKind::Char: {
+        Value *CharVal = coerceValueToType(Val, resolveType("CHAR"));
+        Value *Promoted = Builder->CreateZExt(CharVal, Type::getInt32Ty(*TheContext), "char_for_printf");
+        Fmt = AppendNewline
+            ? PrintfCharFormatStr
+            : Builder->CreateGlobalString("%c", "fmt_chr_inline", 0, TheModule.get());
+        Args.push_back(Fmt);
+        Args.push_back(Promoted);
+        break;
+    }
+
+    case TypeKind::Integer:
+    case TypeKind::Enum: { // an enum prints its ordinal (user decision)
+        Value *IntVal = Info->isEnum() ? Val : coerceValueToType(Val, resolveType("INTEGER"));
+        Fmt = AppendNewline
+            ? PrintfFormatStr
+            : Builder->CreateGlobalString("%lld", "fmt_int_inline", 0, TheModule.get());
+        Args.push_back(Fmt);
+        Args.push_back(IntVal);
+        break;
+    }
+
+    case TypeKind::Record:
+        reportError("Cannot OUTPUT a value of record type %s; output its fields individually",
+                    Info->Name.c_str());
+        return;
+
+    case TypeKind::Pointer:
+        reportError("Cannot OUTPUT a value of pointer type %s", Info->Name.c_str());
+        return;
+
+    case TypeKind::CScalar:
+        emitCOutput(Val, Info, AppendNewline);
+        return;
+    case TypeKind::CPointer:
+        reportError("OUTPUT is not supported for type %s", Info->Name.c_str());
+        return;
+
+    case TypeKind::Void:
+        reportError("Cannot OUTPUT a VOID value");
+        return;
+    }
+
+    Builder->CreateCall(PrintfFunc, Args);
+}
diff --git a/lib/CodeGen/StatementGen.cc b/lib/CodeGen/StatementGen.cc
new file mode 100644
index 0000000..f10d78b
--- /dev/null
+++ b/lib/CodeGen/StatementGen.cc
@@ -0,0 +1,282 @@
+#include "cps/CodeGen.h"
+#include "cps/ArrayHandler.h"
+#include "cps/FileAST.h"
+#include "cps/FileHandler.h"
+#include "cps/ExceptionHandler.h"
+#include "cps/TypeAST.h"
+
+using namespace llvm;
+using namespace cps;
+
+void CodeGen::emitStmt(StmtAST *Stmt) {
+    if (!Stmt) return;
+
+    if (auto *FuncDef = dynamic_cast<FunctionDefAST*>(Stmt)) {
+        BasicBlock *SavedBlock = Builder->GetInsertBlock();
+        // Function bodies get a fresh array scope (metadata SSA values belong
+        // to the emitting function), mirroring FunctionGen's Symbols handling.
+        auto SavedArrays = Arrays->exchangeTable({});
+
+        FuncGen->emitFunctionDef(FuncDef, [this](StmtAST *S) {
+            this->emitStmt(S);
+        });
+
+        Arrays->exchangeTable(std::move(SavedArrays));
+        if (SavedBlock) Builder->SetInsertPoint(SavedBlock);
+        return;
+    }
+
+    // Keep diagnosing statements after RETURN/THROW without appending code
+    // to a terminated block or making those statements reachable.
+    if (Builder->GetInsertBlock()->hasTerminator()) {
+        auto *F = Builder->GetInsertBlock()->getParent();
+        Builder->SetInsertPoint(BasicBlock::Create(*TheContext, "unreachable_code", F));
+    }
+
+    if (auto *Try = dynamic_cast<TryStmtAST*>(Stmt)) {
+        emitTryStmt(Try);
+        return;
+    }
+    if (dynamic_cast<ThrowStmtAST*>(Stmt)) {
+        Exceptions->emitThrow();
+        return;
+    }
+    if (auto *ArrDecl = dynamic_cast<ArrayDeclareStmtAST*>(Stmt)) {
+        Arrays->emitArrayDeclare(ArrDecl, *this);
+        return;
+    }
+    if (auto *ArrAssign = dynamic_cast<ArrayAssignStmtAST*>(Stmt)) {
+        Arrays->emitArrayAssign(ArrAssign, *this);
+        return;
+    }
+
+    if (auto *Call = dynamic_cast<CallStmtAST*>(Stmt)) {
+        std::vector<Value*> Args;
+        if (!marshalCallArgs(Call->getCallee(), Call->getArgs(), Call->getLine(), Args)) return;
+        FuncGen->emitCallStmt(Call, Args);
+        return;
+    }
+
+    if (auto *Ret = dynamic_cast<ReturnStmtAST*>(Stmt)) {
+        Function *F = Builder->GetInsertBlock()->getParent();
+        const FuncSig *Sig = FuncGen->getSignature(F->getName().str());
+        // Pseudocode cannot name a function "main" (reserved runtime symbol),
+        // so no signature means we are emitting the top level.
+        if (!Sig) {
+            reportError("RETURN is only allowed inside a FUNCTION or PROCEDURE");
+            return;
+        }
+        if (F->getReturnType()->isVoidTy() && Ret->getRetVal()) {
+            reportError("RETURN with a value is only allowed in a FUNCTION");
+            return;
+        }
+        if (!F->getReturnType()->isVoidTy() && !Ret->getRetVal()) {
+            reportError("RETURN in a FUNCTION requires a value");
+            return;
+        }
+        Value *RetVal = nullptr;
+        if (Ret->getRetVal()) {
+            RetVal = emitCoercedExpr(Ret->getRetVal(), resolveType(Sig->ReturnTypeName));
+            if (!RetVal) return;
+        }
+        FuncGen->emitReturn(Ret, RetVal);
+        return;
+    }
+
+    if (auto *Decl = dynamic_cast<DeclareStmtAST*>(Stmt)) {
+        emitDeclareStmt(Decl);
+        return;
+    }
+
+    if (auto *Assign = dynamic_cast<AssignStmtAST*>(Stmt)) {
+        const SymbolInfo *Info = getSymbolInfo(Assign->getName());
+        if (!Info) {
+            if (Types->lookupEnumConstant(Assign->getName())) {
+                reportError("Enum value %s is not an assignable location", Assign->getName().c_str());
+            } else {
+                reportError("Unknown variable name %s", Assign->getName().c_str());
+            }
+            return;
+        }
+        if (Info->IsArray) {
+            reportError("Cannot assign array %s without indices", Assign->getName().c_str());
+            return;
+        }
+
+        Value *Val = emitCoercedExpr(Assign->getExpr(), resolveType(Info->TypeName));
+        if (!Val) return;
+
+        Builder->CreateStore(Val, Info->Storage);
+        return;
+    }
+
+    if (auto *In = dynamic_cast<InputStmtAST*>(Stmt)) {
+        const SymbolInfo *Info = getSymbolInfo(In->getName());
+        if (!Info) {
+            reportError("Unknown variable name %s", In->getName().c_str());
+            return;
+        }
+        if (Info->IsArray) {
+            reportError("INPUT for entire array %s is not supported", In->getName().c_str());
+            return;
+        }
+
+        const TypeInfo *TypeInfo = resolveType(Info->TypeName);
+        if (!TypeInfo) {
+            reportError("Unknown type for INPUT %s", In->getName().c_str());
+            return;
+        }
+
+        std::vector<Value*> Args;
+        if (TypeInfo->isC()) {
+            emitCInput(Info, TypeInfo);
+        } else if (TypeInfo->isReal()) {
+            Args.push_back(ScanfFloatFormatStr);
+            Args.push_back(Info->Storage);
+            Builder->CreateCall(ScanfFunc, Args);
+        } else if (TypeInfo->isBoolean()) {
+            AllocaInst *TempInt = CreateEntryBlockAlloca(Builder->GetInsertBlock()->getParent(), "tmp_bool_input");
+            Args.push_back(ScanfFormatStr);
+            Args.push_back(TempInt);
+            Builder->CreateCall(ScanfFunc, Args);
+
+            Value *Val = Builder->CreateLoad(Type::getInt64Ty(*TheContext), TempInt);
+            Value *BoolVal = Builder->CreateICmpNE(Val, ConstantInt::get(*TheContext, APInt(64, 0)), "bool_cast");
+            Builder->CreateStore(BoolVal, Info->Storage);
+        } else if (TypeInfo->isString()) {
+            Value *Mem = Builder->CreateCall(MallocFunc, ConstantInt::get(*TheContext, APInt(64, 1024)), "input_str");
+            Args.push_back(ScanfStringFormatStr);
+            Args.push_back(Mem);
+            Builder->CreateCall(ScanfFunc, Args);
+            Builder->CreateStore(Mem, Info->Storage);
+        } else if (TypeInfo->isChar()) {
+            Value *CharFmt = Builder->CreateGlobalString(" %c", "fmt_in_char", 0, TheModule.get());
+            Args.push_back(CharFmt);
+            Args.push_back(Info->Storage);
+            Builder->CreateCall(ScanfFunc, Args);
+        } else if (TypeInfo->Kind == TypeKind::Integer) {
+            Args.push_back(ScanfFormatStr);
+            Args.push_back(Info->Storage);
+            Builder->CreateCall(ScanfFunc, Args);
+        } else {
+            // Enum/Record/Pointer and any future kind: scanf'ing raw bytes
+            // into typed storage would corrupt it — reject explicitly.
+            reportError("INPUT is not supported for a value of type %s", TypeInfo->Name.c_str());
+        }
+        return;
+    }
+
+    if (auto *Out = dynamic_cast<OutputStmtAST*>(Stmt)) {
+        const auto &Exprs = Out->getExprs();
+        for (size_t I = 0; I < Exprs.size(); ++I) {
+            ExprAST *Expr = Exprs[I].get();
+            if (Arrays->tryEmitArrayOutput(Expr, *this)) continue;
+
+            Value *Val = emitExpr(Expr);
+            const TypeInfo *TypeInfo = getExprTypeInfo(Expr);
+            if (!TypeInfo) {
+                reportError("Cannot infer the type of the OUTPUT expression");
+                continue;
+            }
+            if (TypeInfo->isVoid()) {
+                reportError("Cannot OUTPUT the result of a PROCEDURE call");
+                continue;
+            }
+            emitOutputValue(Val, TypeInfo, I + 1 == Exprs.size());
+        }
+        return;
+    }
+
+    if (auto *Open = dynamic_cast<OpenFileStmtAST*>(Stmt)) {
+        if (isWholeArrayVar(Open->getFileName())) {
+            reportError("Cannot use a whole array as the OPENFILE filename");
+            return;
+        }
+        Value *Name = emitCoercedExpr(Open->getFileName(), resolveType("STRING"));
+        if (!Name) return;
+        Files->emitOpen(Name, Open->getMode(), Open->getLine());
+        return;
+    }
+
+    if (auto *Read = dynamic_cast<ReadFileStmtAST*>(Stmt)) {
+        const SymbolInfo *Info = getSymbolInfo(Read->getVarName());
+        if (!Info) {
+            reportError("Unknown variable name %s", Read->getVarName().c_str());
+            return;
+        }
+        if (Info->IsArray) {
+            reportError("READFILE into entire array %s is not supported", Read->getVarName().c_str());
+            return;
+        }
+        if (Info->TypeName != "STRING") {
+            reportError("READFILE variable %s must be of type STRING (got %s)",
+                        Read->getVarName().c_str(), Info->TypeName.c_str());
+            return;
+        }
+        if (isWholeArrayVar(Read->getFileName())) {
+            reportError("Cannot use a whole array as the READFILE filename");
+            return;
+        }
+        Value *Name = emitCoercedExpr(Read->getFileName(), resolveType("STRING"));
+        if (!Name) return;
+        Value *LineStr = Files->emitRead(Name, Read->getLine());
+        if (!LineStr) return;
+        Builder->CreateStore(LineStr, Info->Storage);
+        return;
+    }
+
+    if (auto *Write = dynamic_cast<WriteFileStmtAST*>(Stmt)) {
+        if (isWholeArrayVar(Write->getFileName()) || isWholeArrayVar(Write->getData())) {
+            reportError("Cannot use a whole array in WRITEFILE");
+            return;
+        }
+        Value *Name = emitCoercedExpr(Write->getFileName(), resolveType("STRING"));
+        Value *Data = emitCoercedExpr(Write->getData(), resolveType("STRING"));
+        if (!Name || !Data) return;
+        Files->emitWrite(Name, Data, Write->getLine());
+        return;
+    }
+
+    if (auto *Close = dynamic_cast<CloseFileStmtAST*>(Stmt)) {
+        if (isWholeArrayVar(Close->getFileName())) {
+            reportError("Cannot use a whole array as the CLOSEFILE filename");
+            return;
+        }
+        Value *Name = emitCoercedExpr(Close->getFileName(), resolveType("STRING"));
+        if (!Name) return;
+        Files->emitClose(Name, Close->getLine());
+        return;
+    }
+
+    if (auto *IfStmt = dynamic_cast<IfStmtAST*>(Stmt)) {
+        emitIfStmt(IfStmt);
+        return;
+    }
+    if (auto *WhileStmt = dynamic_cast<WhileStmtAST*>(Stmt)) {
+        emitWhileStmt(WhileStmt);
+        return;
+    }
+    if (auto *RepeatStmt = dynamic_cast<RepeatStmtAST*>(Stmt)) {
+        emitRepeatStmt(RepeatStmt);
+        return;
+    }
+    if (auto *ForStmt = dynamic_cast<ForStmtAST*>(Stmt)) {
+        emitForStmt(ForStmt);
+        return;
+    }
+
+    // TYPE declarations are registered by compile()'s pre-pass (the parser
+    // guarantees they are top-level); nothing is emitted here.
+    if (dynamic_cast<EnumTypeDeclAST*>(Stmt) || dynamic_cast<PointerTypeDeclAST*>(Stmt) ||
+        dynamic_cast<RecordTypeDeclAST*>(Stmt) || dynamic_cast<CTypeDeclAST*>(Stmt)) {
+        return;
+    }
+    if (auto *DA = dynamic_cast<DesignatorAssignStmtAST*>(Stmt)) {
+        LValueInfo LV;
+        if (!emitLValue(DA->getTarget(), LV)) return;
+        Value *Val = emitCoercedExpr(DA->getExpr(), resolveType(LV.TypeName));
+        if (!Val) return;
+        Builder->CreateStore(Val, LV.Addr);
+        return;
+    }
+}
diff --git a/lib/CodeGen/ValueTypeGen.cc b/lib/CodeGen/ValueTypeGen.cc
new file mode 100644
index 0000000..70def81
--- /dev/null
+++ b/lib/CodeGen/ValueTypeGen.cc
@@ -0,0 +1,274 @@
+#include "cps/CodeGen.h"
+#include "cps/Lexer.h"
+#include "cps/TypeAST.h"
+#include "Builtins.h"
+
+using namespace llvm;
+using namespace cps;
+
+using namespace cps::detail;
+
+const TypeInfo *CodeGen::getExprTypeInfo(ExprAST *Expr) const {
+    if (!Expr) return nullptr;
+
+    if (dynamic_cast<IntegerExprAST*>(Expr)) return resolveType("INTEGER");
+    if (dynamic_cast<RealExprAST*>(Expr)) return resolveType("REAL");
+    if (dynamic_cast<BooleanExprAST*>(Expr)) return resolveType("BOOLEAN");
+    if (dynamic_cast<CharExprAST*>(Expr)) return resolveType("CHAR");
+    if (dynamic_cast<StringExprAST*>(Expr)) return resolveType("STRING");
+    if (auto *Cast = dynamic_cast<CastExprAST*>(Expr))
+        return resolveType(Cast->getTypeName());
+
+    if (auto *Var = dynamic_cast<VariableExprAST*>(Expr)) {
+        const SymbolInfo *Info = getSymbolInfo(Var->getName());
+        if (Info) return resolveType(Info->TypeName);
+        if (const EnumConstant *EC = Types->lookupEnumConstant(Var->getName())) {
+            return resolveType(EC->TypeName);
+        }
+        return nullptr;
+    }
+
+    if (auto *Arr = dynamic_cast<ArrayAccessExprAST*>(Expr)) {
+        const SymbolInfo *Info = getSymbolInfo(Arr->getName());
+        return Info ? resolveType(Info->TypeName) : nullptr;
+    }
+
+    if (auto *D = dynamic_cast<DesignatorExprAST*>(Expr)) {
+        const SymbolInfo *Info = getSymbolInfo(D->getBaseName());
+        if (!Info) return nullptr;
+        std::string TypeName = Info->TypeName;
+        size_t Start = 0;
+        if (Info->IsArray) {
+            // SymbolInfo already holds the ELEMENT type name for arrays.
+            if (D->getAccesses().empty() || D->getAccesses()[0].Kind != AccessKind::Index)
+                return nullptr;
+            Start = 1;
+        }
+        for (size_t I = Start; I < D->getAccesses().size(); ++I) {
+            const TypeInfo *Cur = resolveType(TypeName);
+            if (!Cur) return nullptr;
+            const DesignatorAccess &A = D->getAccesses()[I];
+            if (A.Kind == AccessKind::Field) {
+                const RecordPayload *RP = Cur->asRecord();
+                const RecordFieldInfo *FI = RP ? RP->findField(A.FieldName) : nullptr;
+                if (!FI) return nullptr;
+                if (!FI->IsPublic) return nullptr;
+                TypeName = FI->TypeName;
+            } else if (A.Kind == AccessKind::Deref) {
+                const PointerPayload *PP = Cur->asPointer();
+                if (!PP) return nullptr;
+                TypeName = PP->PointeeTypeName;
+            } else {
+                return nullptr; // indexing a non-array
+            }
+        }
+        return resolveType(TypeName);
+    }
+
+    // ^x has no pseudocode type of its own; only the pointer admission in
+    // emitCoercedExpr may consume it.
+    if (dynamic_cast<AddrOfExprAST*>(Expr)) return nullptr;
+
+    if (auto *Unary = dynamic_cast<UnaryExprAST*>(Expr)) {
+        if (Unary->getOp() == tok_not) {
+            return resolveType("BOOLEAN");
+        }
+        const TypeInfo *Operand = getExprTypeInfo(Unary->getOperand());
+        if (Operand && Operand->isC()) return Types->promoteCScalar(Operand);
+        if (Operand && !Operand->isC() && !Operand->isUserKind())
+            return Operand->isReal() ? resolveType("REAL") : resolveType("INTEGER");
+        return nullptr;
+    }
+
+    if (auto *Bin = dynamic_cast<BinaryExprAST*>(Expr)) {
+        switch (Bin->getOp()) {
+            case tok_eq:
+            case tok_ne:
+            case '<':
+            case '>':
+            case tok_le:
+            case tok_ge:
+            case tok_and:
+            case tok_or:
+                return resolveType("BOOLEAN");
+            case '&':
+                return resolveType("STRING");
+            case '/':
+                return resolveType("REAL");
+            default:
+                break;
+        }
+
+        const TypeInfo *L = getExprTypeInfo(Bin->getLHS());
+        const TypeInfo *R = getExprTypeInfo(Bin->getRHS());
+        if ((L && L->isC()) || (R && R->isC())) return Types->commonCScalar(L, R);
+        // Enum arithmetic: E +/- INTEGER (enum on the left) yields the enum;
+        // every other user-kind combination has no type (emission rejects it).
+        if ((L && L->isUserKind()) || (R && R->isUserKind())) {
+            if (L && L->isEnum() && R && R->Kind == TypeKind::Integer &&
+                (Bin->getOp() == '+' || Bin->getOp() == '-')) {
+                return L;
+            }
+            return nullptr;
+        }
+        if ((L && L->Kind == TypeKind::Real) || (R && R->Kind == TypeKind::Real)) {
+            return resolveType("REAL");
+        }
+        return resolveType("INTEGER");
+    }
+
+    if (auto *Call = dynamic_cast<CallExprAST*>(Expr)) {
+        const std::string &Name = Call->getCallee();
+        if (const BuiltinInfo *B = findBuiltin(Name)) {
+            return resolveType(B->ReturnTypeName);
+        }
+        if (const FuncSig *Sig = FuncGen->getSignature(Name)) {
+            return resolveType(Sig->ReturnTypeName);
+        }
+
+        Function *CalleeF = TheModule->getFunction(Name);
+        if (!CalleeF) return resolveType("INTEGER");
+
+        Type *RetTy = CalleeF->getReturnType();
+        if (RetTy->isVoidTy()) return resolveType("VOID");
+        if (RetTy->isDoubleTy()) return resolveType("REAL");
+        if (RetTy->isIntegerTy(1)) return resolveType("BOOLEAN");
+        if (RetTy->isIntegerTy(8)) return resolveType("CHAR");
+        if (RetTy->isPointerTy()) return resolveType("STRING");
+        return resolveType("INTEGER");
+    }
+
+    return nullptr;
+}
+
+Value *CodeGen::coerceValueToType(Value *Val, const TypeInfo *TargetInfo) {
+    if (!Val || !TargetInfo || !TargetInfo->LLVMType) return nullptr;
+
+    if (Val->getType() == TargetInfo->LLVMType) {
+        return Val;
+    }
+
+    switch (TargetInfo->Kind) {
+        case TypeKind::Real:
+            if (Val->getType()->isDoubleTy()) return Val;
+            if (Val->getType()->isIntegerTy(1))
+                return Builder->CreateUIToFP(Val, Type::getDoubleTy(*TheContext), "bool_to_real");
+            if (Val->getType()->isIntegerTy(8))
+                return Builder->CreateUIToFP(Val, Type::getDoubleTy(*TheContext), "char_to_real");
+            if (Val->getType()->isIntegerTy())
+                return Builder->CreateSIToFP(Val, Type::getDoubleTy(*TheContext), "int_to_real");
+            break;
+
+        case TypeKind::Integer:
+            if (Val->getType()->isIntegerTy(64)) return Val;
+            if (Val->getType()->isDoubleTy())
+                return Builder->CreateFPToSI(Val, Type::getInt64Ty(*TheContext), "real_to_int");
+            if (Val->getType()->isIntegerTy(1))
+                return Builder->CreateZExt(Val, Type::getInt64Ty(*TheContext), "bool_to_int");
+            if (Val->getType()->isIntegerTy(8))
+                return Builder->CreateZExt(Val, Type::getInt64Ty(*TheContext), "char_to_int");
+            if (Val->getType()->isIntegerTy())
+                return Builder->CreateSExtOrTrunc(Val, Type::getInt64Ty(*TheContext), "int_cast");
+            break;
+
+        case TypeKind::Boolean:
+            if (Val->getType()->isIntegerTy(1)) return Val;
+            if (Val->getType()->isIntegerTy())
+                return Builder->CreateICmpNE(Val, Constant::getNullValue(Val->getType()), "to_bool");
+            if (Val->getType()->isDoubleTy())
+                return Builder->CreateFCmpONE(Val, ConstantFP::get(*TheContext, APFloat(0.0)), "to_bool");
+            if (Val->getType()->isPointerTy())
+                return Builder->CreateICmpNE(Val,
+                                             ConstantPointerNull::get(cast<PointerType>(Val->getType())),
+                                             "ptr_to_bool");
+            break;
+
+        case TypeKind::Char:
+            if (Val->getType()->isIntegerTy(8)) return Val;
+            if (Val->getType()->isIntegerTy(1))
+                return Builder->CreateZExt(Val, Type::getInt8Ty(*TheContext), "bool_to_char");
+            if (Val->getType()->isDoubleTy())
+                return Builder->CreateFPToUI(Val, Type::getInt8Ty(*TheContext), "real_to_char");
+            if (Val->getType()->isIntegerTy())
+                return Builder->CreateTruncOrBitCast(Val, Type::getInt8Ty(*TheContext), "int_to_char");
+            break;
+
+        case TypeKind::String:
+            if (Val->getType()->isPointerTy()) return Val;
+            if (Val->getType()->isIntegerTy(1)) {
+                return Builder->CreateSelect(Val, TrueStr, FalseStr, "bool_to_str");
+            }
+            if (Val->getType()->isDoubleTy()) {
+                return StrConvHandler->emitNumToStr(Val, true);
+            }
+            if (Val->getType()->isIntegerTy(8)) {
+                Value *Mem = Builder->CreateCall(MallocFunc,
+                                                 ConstantInt::get(*TheContext, APInt(64, 2)),
+                                                 "char_str");
+                Builder->CreateStore(Val, Mem);
+                Value *NullPtr = Builder->CreateInBoundsGEP(Type::getInt8Ty(*TheContext),
+                                                            Mem,
+                                                            ConstantInt::get(*TheContext, APInt(64, 1)));
+                Builder->CreateStore(ConstantInt::get(Type::getInt8Ty(*TheContext), 0), NullPtr);
+                return Mem;
+            }
+            if (Val->getType()->isIntegerTy()) {
+                Value *AsInt = coerceValueToType(Val, resolveType("INTEGER"));
+                return AsInt ? StrConvHandler->emitNumToStr(AsInt, false) : nullptr;
+            }
+            break;
+
+        case TypeKind::Void:
+            return nullptr;
+
+        // Enum/Record/Pointer identity lives in the type NAME; at this level
+        // an enum is a plain i64 and a pointer a plain ptr, so nothing can be
+        // checked here. emitCoercedExpr is the only legitimate door.
+        case TypeKind::Enum:
+        case TypeKind::Record:
+        case TypeKind::Pointer:
+        case TypeKind::CScalar:
+        case TypeKind::CPointer:
+            reportError("Internal: a %s value reached representation coercion without a name-level check",
+                        TargetInfo->Name.c_str());
+            return nullptr;
+    }
+
+    reportError("Cannot coerce value of LLVM type to target type %s",
+            TargetInfo->Name.c_str());
+    return nullptr;
+}
+
+void CodeGen::emitDeclareStmt(DeclareStmtAST *Stmt) {
+    const TypeInfo *Info = resolveType(Stmt->getType());
+    if (!Info || !Info->LLVMType || Info->isVoid()) {
+        reportError("Unknown type %s", Stmt->getType().c_str());
+        return;
+    }
+    if (Types->lookupEnumConstant(Stmt->getName())) {
+        reportError("'%s' is an enum value and cannot be declared as a variable",
+                    Stmt->getName().c_str());
+        return;
+    }
+    if (Types->resolve(Stmt->getName())) {
+        reportError("'%s' is a type name and cannot be declared as a variable",
+                    Stmt->getName().c_str());
+        return;
+    }
+
+    Function *TheFunction = Builder->GetInsertBlock()->getParent();
+    AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, Info->LLVMType, Stmt->getName());
+
+    Value *InitVal = nullptr;
+    if (Info->isString()) {
+        InitVal = EmptyStringStr;
+    } else {
+        InitVal = Types->getZeroValue(Info->Name);
+    }
+
+    if (InitVal) {
+        Builder->CreateStore(InitVal, Alloca);
+    }
+
+    registerSymbol(Stmt->getName(), Alloca, Info->Name, false);
+}