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#include "cps/CodeGen.h"
#include <cstdio>
using namespace llvm;
using namespace cps;
// Only bindings introduced by constants or hiding constants are restored.
// Ordinary variables keep the compiler's existing function-wide visibility.
void CodeGen::emitScopedBlock(const std::vector<std::unique_ptr<StmtAST>> &Body) {
ConstantScopes.push_back({NextScopeID++, {}});
for (const auto &S : Body) emitStmt(S.get());
for (const auto &[Name, Previous] : ConstantScopes.back().Saved) {
if (Previous) Symbols[Name] = *Previous;
else Symbols.erase(Name);
}
ConstantScopes.pop_back();
}
void CodeGen::warnMemberShadow(const std::string &Name, int Line) const {
if (CurrentClass.empty()) return;
const TypeInfo *Class = resolveType(CurrentClass);
const RecordPayload *Record = Class ? Class->asRecord() : nullptr;
if (Record && Record->findField(Name)) {
fprintf(stderr, "warning: Declaration of %s shadows a field of class %s at line %d\n",
Name.c_str(), CurrentClass.c_str(), Line);
}
}
bool CodeGen::prepareSymbolDeclaration(const std::string &Name, bool IsConstant) {
if (!CurrentClass.empty() && sameIdentifier(Name, "this")) {
reportError("Cannot redeclare this inside a method");
return false;
}
auto &Scope = ConstantScopes.back();
auto It = Symbols.find(Name);
if (It != Symbols.end()) {
if (It->second.ScopeID == Scope.ID) {
reportError("Declaration of %s conflicts with an existing declaration in this scope", Name.c_str());
return false;
}
if (IsConstant || It->second.ConstantValue) Scope.Saved.emplace(Name, It->second);
} else if (IsConstant) {
Scope.Saved.emplace(Name, std::nullopt);
}
warnMemberShadow(Name, DiagnosticLine);
return true;
}
bool CodeGen::requireWritable(const SymbolInfo &Info, const std::string &Name) {
if (!Info.ConstantValue) return true;
reportError("Constant %s is not a writable location", Name.c_str());
return false;
}
void CodeGen::emitConstantStmt(ConstantStmtAST *Stmt) {
const std::string &Name = Stmt->getName();
if (Types->lookupEnumConstant(Name) || Types->resolve(Name)) {
reportError("Constant %s conflicts with an enum value or type name", Name.c_str());
return;
}
if (ConstantScopes.back().ID == 0 &&
(FuncGen->getSignature(Name) || isBuiltinName(Name))) {
reportError("Constant %s conflicts with a function name", Name.c_str());
return;
}
if (!prepareSymbolDeclaration(Name, true)) return;
const TypeInfo *Type = getExprTypeInfo(Stmt->getValue());
Value *Val = emitExpr(Stmt->getValue());
auto *Literal = dyn_cast_or_null<Constant>(Val);
if (!Type || !Literal) {
reportError("CONSTANT initializer must be a literal");
return;
}
Symbols[Name] = {nullptr, Type->Name, false, Literal, ConstantScopes.back().ID};
}
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