enable setting "-O optimize-AST" option

src/Options.cc

@@ -151,6 +151,7 @@ static void set_analysis_option(const char* opt, Options& opts)
 		{
 		opts.analysis_options.inliner = true;
 		opts.analysis_options.activate = true;
+		opts.analysis_options.optimize_AST = true;
 		return;
 		}
 
@@ -161,6 +162,7 @@ static void set_analysis_option(const char* opt, Options& opts)
 		fprintf(stderr, "    dump-xform	dump transformed scripts to stdout; implies xform\n");
 		fprintf(stderr, "    help	print this list\n");
 		fprintf(stderr, "    inline	inline function calls\n");
+		fprintf(stderr, "    optimize-AST	optimize the (transformed) AST; implies xform\n");
 		fprintf(stderr, "    recursive	report on recursive functions and exit\n");
 		fprintf(stderr, "    xform	tranform scripts to \"reduced\" form\n");
 		exit(0);
@@ -178,6 +180,8 @@ static void set_analysis_option(const char* opt, Options& opts)
 		a_o.inliner = a_o.report_recursive = true;
 	else if ( util::streq(opt, "xform") )
 		a_o.activate = true;
+	else if ( util::streq(opt, "optimize-AST") )
+		a_o.activate = a_o.optimize_AST = true;
 
 	else
 		{

src/script_opt/ScriptOpt.cc

@@ -133,6 +133,7 @@ void analyze_scripts()
 		check_env_opt("ZEEK_DUMP_XFORM", analysis_options.dump_xform);
 		check_env_opt("ZEEK_DUMP_UDS", analysis_options.dump_uds);
 		check_env_opt("ZEEK_INLINE", analysis_options.inliner);
+		check_env_opt("ZEEK_OPT", analysis_options.optimize_AST);
 		check_env_opt("ZEEK_XFORM", analysis_options.activate);
 
 		auto usage = getenv("ZEEK_USAGE_ISSUES");
@@ -148,6 +149,7 @@ void analyze_scripts()
 			}
 
 		if ( analysis_options.only_func ||
+		     analysis_options.optimize_AST ||
 		     analysis_options.usage_issues > 0 )
 			analysis_options.activate = true;
 
@@ -157,6 +159,12 @@ void analyze_scripts()
 	if ( ! analysis_options.activate && ! analysis_options.inliner )
 		return;
 
+	if ( analysis_options.usage_issues > 0 && analysis_options.optimize_AST )
+		{
+		fprintf(stderr, "warning: \"-O optimize-AST\" option is incompatible with -u option, deactivating optimization\n");
+		analysis_options.optimize_AST = false;
+		}
+
 	// Now that everything's parsed and BiF's have been initialized,
 	// profile the functions.
 	std::unordered_map<const ScriptFunc*, std::shared_ptr<ProfileFunc>>

src/script_opt/ScriptOpt.h

@@ -22,6 +22,9 @@ struct AnalyOpt {
 	// Whether to analyze scripts.
 	bool activate = false;
 
+	// Whether to optimize the AST.
+	bool optimize_AST = false;
+
 	// If true, dump out transformed code: the results of reducing
 	// interpreted scripts, and, if optimize is set, of then optimizing
 	// them.  Always done if only_func is set.