[yul-phaser] Make Program copyable by doing a deep copy of the AST in the copy constructor

test/yulPhaser/Program.cpp

@@ -65,6 +65,26 @@ namespace solidity::phaser::test
 BOOST_AUTO_TEST_SUITE(Phaser)
 BOOST_AUTO_TEST_SUITE(ProgramTest)
 
+BOOST_AUTO_TEST_CASE(copy_constructor_should_make_deep_copy_of_ast)
+{
+	string sourceCode(
+		"{\n"
+		"    let x := 1\n"
+		"}\n"
+	);
+	CharStream sourceStream(sourceCode, current_test_case().p_name);
+	auto program = Program::load(sourceStream);
+
+	Program programCopy(program);
+
+	BOOST_TEST(&programCopy.ast() != &program.ast());
+
+	// There might be a more direct way to compare ASTs but converting to JSON should be good enough
+	// as long as the conversion is deterministic. A very nice side effect of doing it this way is
+	// that BOOST_TEST will print the complete AST structure of both programs in case of a mismatch.
+	BOOST_TEST(programCopy.toJson() == program.toJson());
+}
+
 BOOST_AUTO_TEST_CASE(load_should_rewind_the_stream)
 {
 	string sourceCode(

tools/yulPhaser/Program.cpp

@@ -57,6 +57,13 @@ ostream& operator<<(ostream& _stream, Program const& _program);
 
 }
 
+Program::Program(Program const& program):
+	m_ast(make_unique<Block>(get<Block>(ASTCopier{}(*program.m_ast)))),
+	m_dialect{program.m_dialect},
+	m_nameDispenser(program.m_nameDispenser)
+{
+}
+
 Program Program::load(CharStream& _sourceCode)
 {
 	// ASSUMPTION: parseSource() rewinds the stream on its own

tools/yulPhaser/Program.h

@@ -20,8 +20,6 @@
 #include <libyul/optimiser/NameDispenser.h>
 #include <libyul/AsmData.h>
 
-#include <boost/noncopyable.hpp>
-
 #include <optional>
 #include <ostream>
 #include <set>
@@ -55,14 +53,16 @@ namespace solidity::phaser
  * The class allows the user to apply extra optimisations and obtain metrics and general
  * information about the resulting syntax tree.
  */
-class Program: private boost::noncopyable
+class Program
 {
 public:
+	Program(Program const& program);
 	Program(Program&& program):
 		m_ast(std::move(program.m_ast)),
 		m_dialect{program.m_dialect},
 		m_nameDispenser(std::move(program.m_nameDispenser))
 	{}
+	Program operator=(Program const& program) = delete;
 	Program operator=(Program&& program) = delete;
 
 	static Program load(langutil::CharStream& _sourceCode);