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// User-defined type registration and addressable designator access.
#include "cps/CodeGen.h"
#include "cps/ArrayHandler.h"
#include "cps/TypeAST.h"
using namespace llvm;
using namespace cps;
// Registers every top-level TYPE declaration before prototypes are emitted.
// Two passes so a pointer TYPE may reference a type declared later
// (TYPE NodePtr = ^Node before TYPE Node — required for linked structures);
// by-value record fields still require their record type to be complete,
// which pass B's source order enforces.
void CodeGen::runTypePrePass(const std::vector<std::unique_ptr<StmtAST>> &Statements) {
std::string Err;
for (const auto &S : Statements) {
bool Ok = true;
if (auto *C = dynamic_cast<CTypeDeclAST*>(S.get()))
Ok = Types->defineCAlias(C->getName(), C->getExpression(), Err);
else if (auto *E = dynamic_cast<EnumTypeDeclAST*>(S.get()))
Ok = Types->declareUserType(E->getName(), TypeKind::Enum, Err);
else if (auto *P = dynamic_cast<PointerTypeDeclAST*>(S.get()))
Ok = Types->declareUserType(P->getName(), TypeKind::Pointer, Err);
else if (auto *R = dynamic_cast<RecordTypeDeclAST*>(S.get()))
Ok = Types->declareUserType(R->getName(), TypeKind::Record, Err);
if (!Ok) reportError("%s", Err.c_str());
}
for (const auto &S : Statements) {
bool Ok = true;
if (auto *E = dynamic_cast<EnumTypeDeclAST*>(S.get())) {
Ok = Types->defineEnum(E->getName(), E->getValueNames(), Err);
} else if (auto *P = dynamic_cast<PointerTypeDeclAST*>(S.get())) {
Ok = Types->definePointer(P->getName(), P->getPointeeTypeName(), Err);
} else if (auto *R = dynamic_cast<RecordTypeDeclAST*>(S.get())) {
Ok = Types->defineRecord(R->getName(), R->getFields(), Err);
}
if (!Ok) reportError("%s", Err.c_str());
}
}
// Resolves a designator (or legacy variable/array-access node) to the address
// of its storage plus the type name stored there. Array indexing goes through
// ArrayHandler's checked pipeline; dereferences emit the null-pointer check.
bool CodeGen::emitLValue(ExprAST *E, LValueInfo &Out) {
if (auto *Var = dynamic_cast<VariableExprAST*>(E)) {
const SymbolInfo *Info = getSymbolInfo(Var->getName());
if (!Info) {
if (Types->lookupEnumConstant(Var->getName())) {
reportError("Enum value %s is not an assignable location", Var->getName().c_str());
} else {
reportError("Unknown variable name %s", Var->getName().c_str());
}
return false;
}
if (Info->IsArray) {
reportError("Whole array %s is not an assignable location; index it", Var->getName().c_str());
return false;
}
Out.Addr = Info->Storage;
Out.TypeName = Info->TypeName;
return true;
}
if (auto *Acc = dynamic_cast<ArrayAccessExprAST*>(E)) {
Out.Addr = Arrays->emitElementAddress(Acc, *this, Out.TypeName);
return Out.Addr != nullptr;
}
auto *D = dynamic_cast<DesignatorExprAST*>(E);
if (!D) {
reportError("Expression is not an assignable location");
return false;
}
const SymbolInfo *Info = getSymbolInfo(D->getBaseName());
if (!Info) {
if (Types->lookupEnumConstant(D->getBaseName())) {
reportError("Enum value %s is not an assignable location", D->getBaseName().c_str());
} else {
reportError("Unknown variable name %s", D->getBaseName().c_str());
}
return false;
}
const auto &Accesses = D->getAccesses();
Value *Addr = Info->Storage;
std::string TypeName = Info->TypeName;
size_t Start = 0;
if (Info->IsArray) {
if (Accesses.empty() || Accesses[0].Kind != AccessKind::Index) {
reportError("Array %s must be indexed before '.' or '^' access", D->getBaseName().c_str());
return false;
}
Addr = Arrays->emitElementAddress(D->getBaseName(), Accesses[0].Indices,
D->getLine(), *this, TypeName);
if (!Addr) return false;
Start = 1;
}
for (size_t I = Start; I < Accesses.size(); ++I) {
const DesignatorAccess &A = Accesses[I];
const TypeInfo *Cur = resolveType(TypeName);
if (!Cur) {
reportError("Unknown type %s", TypeName.c_str());
return false;
}
switch (A.Kind) {
case AccessKind::Field: {
const RecordPayload *RP = Cur->asRecord();
if (!RP) {
reportError("Type %s is not a record; '.%s' is invalid",
TypeName.c_str(), A.FieldName.c_str());
return false;
}
const RecordFieldInfo *FI = RP->findField(A.FieldName);
if (!FI) {
reportError("Record type %s has no field %s", TypeName.c_str(), A.FieldName.c_str());
return false;
}
if (!FI->IsPublic) {
reportError("Cannot access private field %s of type %s",
A.FieldName.c_str(), TypeName.c_str());
return false;
}
Addr = Builder->CreateStructGEP(Cur->LLVMType, Addr, FI->Index,
TypeName + "." + A.FieldName);
TypeName = FI->TypeName;
break;
}
case AccessKind::Deref: {
const PointerPayload *PP = Cur->asPointer();
if (!PP) {
reportError("Cannot dereference a value of type %s ('^' needs a pointer)",
TypeName.c_str());
return false;
}
const TypeInfo *Pointee = resolveType(PP->PointeeTypeName);
if (!Pointee || Pointee->isVoid()) {
reportError("Cannot dereference a void pointer");
return false;
}
Value *P = Builder->CreateLoad(PointerType::getUnqual(*TheContext), Addr, "deref_ptr");
RuntimeChecker->emitNullDerefCheck(P, D->getLine());
Addr = P;
TypeName = PP->PointeeTypeName;
break;
}
case AccessKind::Index:
reportError("Cannot index a value of type %s (only declared arrays can be indexed)",
TypeName.c_str());
return false;
}
}
Out.Addr = Addr;
Out.TypeName = TypeName;
return true;
}
Value *CodeGen::loadFromLValue(const LValueInfo &LV) {
const TypeInfo *Info = resolveType(LV.TypeName);
if (!Info || !Info->LLVMType) {
reportError("Unknown type %s", LV.TypeName.c_str());
return nullptr;
}
Value *Val = Builder->CreateLoad(Info->LLVMType, LV.Addr);
if (Info->isString()) {
Val = emitStringNullGuard(Val);
}
return Val;
}
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