initial implementation of class for temporary variables; this will grow in complexity as we add additional optimization stages

src/CMakeLists.txt

@@ -327,6 +327,7 @@ set(MAIN_SRCS
     script_opt/ProfileFunc.cc
     script_opt/ScriptOpt.cc
     script_opt/Stmt.cc
+    script_opt/TempVar.cc
 
     nb_dns.c
     digest.h

src/script_opt/TempVar.cc

@@ -0,0 +1,17 @@
+// See the file "COPYING" in the main distribution directory for copyright.
+
+#include "TempVar.h"
+#include "Reporter.h"
+
+
+namespace zeek::detail {
+
+TempVar::TempVar(int num, const TypePtr& t, ExprPtr _rhs) : type(t)
+	{
+	char buf[8192];
+	snprintf(buf, sizeof buf, "#%d", num);
+	name = util::copy_string(buf);
+	id = nullptr;
+	}
+
+} // zeek::detail

src/script_opt/TempVar.h

@@ -0,0 +1,36 @@
+// See the file "COPYING" in the main distribution directory for copyright.
+
+#pragma once
+
+// Class for managing temporary variables created during statement reduction
+// for compilation.
+
+#include "ID.h"
+#include "Expr.h"
+
+
+namespace zeek::detail {
+
+class TempVar {
+public:
+	TempVar(int num, const TypePtr& t, ExprPtr rhs);
+	~TempVar()	{ delete name; }
+
+	const char* Name() const	{ return name; }
+	const zeek::Type* Type() const	{ return type.get(); }
+	const Expr* RHS() const		{ return rhs.get(); }
+
+	IDPtr Id() const	{ return id; }
+	void SetID(IDPtr _id)	{ id = std::move(_id); }
+	void Deactivate()	{ active = false; }
+	bool IsActive() const	{ return active; }
+
+protected:
+	char* name;
+	IDPtr id;
+	const TypePtr& type;
+	ExprPtr rhs;
+	bool active = true;
+};
+
+} // zeek::detail