diff --git a/src/script_opt/CPP/DeclFunc.cc b/src/script_opt/CPP/DeclFunc.cc
index 02674029ca..da7b3fa377 100644
--- a/src/script_opt/CPP/DeclFunc.cc
+++ b/src/script_opt/CPP/DeclFunc.cc
@@ -219,12 +219,12 @@ string CPPCompile::BindArgs(const FuncTypePtr& ft, const IDPList* lambda_ids)
 	for ( auto i = 0; i < n; ++i )
 		{
 		auto arg_i = string("f->GetElement(") + Fmt(i) + ")";
-		const auto& ft = params->GetFieldType(i);
+		const auto& pt = params->GetFieldType(i);
 
-		if ( IsNativeType(ft) )
-			res += arg_i + NativeAccessor(ft);
+		if ( IsNativeType(pt) )
+			res += arg_i + NativeAccessor(pt);
 		else
-			res += GenericValPtrToGT(arg_i, ft, GEN_VAL_PTR);
+			res += GenericValPtrToGT(arg_i, pt, GEN_VAL_PTR);
 
 		res += ", ";
 		}
diff --git a/src/script_opt/CPP/Exprs.cc b/src/script_opt/CPP/Exprs.cc
index b21d12b77d..8a6dc49de5 100644
--- a/src/script_opt/CPP/Exprs.cc
+++ b/src/script_opt/CPP/Exprs.cc
@@ -620,11 +620,11 @@ string CPPCompile::GenRecordConstructorExpr(const Expr* e)
 
 	for ( auto i = 0; i < n; ++i )
 		{
-		const auto& e = exprs[i];
+		const auto& expr = exprs[i];
 
-		ASSERT(e->Tag() == EXPR_FIELD_ASSIGN);
+		ASSERT(expr->Tag() == EXPR_FIELD_ASSIGN);
 
-		vals += GenExpr(e->GetOp1(), GEN_VAL_PTR);
+		vals += GenExpr(expr->GetOp1(), GEN_VAL_PTR);
 
 		if ( i < n - 1 )
 			vals += ", ";
@@ -668,12 +668,12 @@ string CPPCompile::GenTableConstructorExpr(const Expr* e)
 
 	for ( auto i = 0; i < n; ++i )
 		{
-		const auto& e = exprs[i];
+		const auto& expr = exprs[i];
 
-		ASSERT(e->Tag() == EXPR_ASSIGN);
+		ASSERT(expr->Tag() == EXPR_ASSIGN);
 
-		auto index = e->GetOp1();
-		auto v = e->GetOp2();
+		auto index = expr->GetOp1();
+		auto v = expr->GetOp2();
 
 		if ( index->Tag() == EXPR_LIST )
 			// Multiple indices.
diff --git a/src/script_opt/CPP/Types.cc b/src/script_opt/CPP/Types.cc
index b4ef3555fc..38511b5c85 100644
--- a/src/script_opt/CPP/Types.cc
+++ b/src/script_opt/CPP/Types.cc
@@ -44,6 +44,7 @@ bool CPPCompile::IsNativeType(const TypePtr& t) const
 
 	default:
 		reporter->InternalError("bad type in CPPCompile::IsNativeType");
+		return false;
 	}
 	}
 
@@ -287,6 +288,7 @@ const char* CPPCompile::TypeTagName(TypeTag tag) const
 
 	default:
 		reporter->InternalError("bad type in CPPCompile::TypeTagName");
+		return nullptr;
 	}
 	}
 
@@ -318,6 +320,7 @@ const char* CPPCompile::TypeName(const TypePtr& t)
 
 	default:
 		reporter->InternalError("bad type in CPPCompile::TypeName");
+		return nullptr;
 	}
 	}
 
@@ -353,6 +356,7 @@ const char* CPPCompile::FullTypeName(const TypePtr& t)
 
 	default:
 		reporter->InternalError("bad type in CPPCompile::FullTypeName");
+		return nullptr;
 	}
 	}
 
@@ -365,6 +369,7 @@ const char* CPPCompile::TypeType(const TypePtr& t)
 
 	default:
 		reporter->InternalError("bad type in CPPCompile::TypeType");
+		return nullptr;
 	}
 	}
 
@@ -542,6 +547,7 @@ const char* CPPCompile::NativeAccessor(const TypePtr& t)
 
 	default:
 		reporter->InternalError("bad type in CPPCompile::NativeAccessor");
+		return nullptr;
 	}
 	}
 
@@ -572,6 +578,7 @@ const char* CPPCompile::IntrusiveVal(const TypePtr& t)
 
 	default:
 		reporter->InternalError("bad type in CPPCompile::IntrusiveVal");
+		return nullptr;
 	}
 	}