put global statements into a quasi-function to support script optimization

src/parse.y

@@ -266,7 +266,7 @@ static bool expr_is_table_type_name(const zeek::detail::Expr* expr)
 
 %%
 
-bro:
+zeek:
 		decl_list stmt_list
 			{
 			if ( zeek::detail::stmts )

src/script_opt/ScriptOpt.cc

@@ -3,6 +3,7 @@
 #include "zeek/Options.h"
 #include "zeek/Reporter.h"
 #include "zeek/Desc.h"
+#include "zeek/module_util.h"
 #include "zeek/script_opt/ScriptOpt.h"
 #include "zeek/script_opt/ProfileFunc.h"
 #include "zeek/script_opt/Inline.h"
@@ -153,6 +154,28 @@ void analyze_func(ScriptFuncPtr f)
 	funcs.emplace_back(f, ScopePtr{NewRef{}, f->GetScope()}, f->CurrentBody());
 	}
 
+const FuncInfo* analyze_global_stmts(Stmt* stmts)
+	{
+	// We ignore analysis_options.only_func - if it's in use, later
+	// logic will keep this function from being compiled, but it's handy
+	// now to enter it into "funcs" so we have a FuncInfo to return.
+
+	auto id = install_ID("<global-stmts>", GLOBAL_MODULE_NAME, true, false);
+	auto empty_args_t = make_intrusive<RecordType>(nullptr);
+	auto func_t = make_intrusive<FuncType>(empty_args_t, nullptr, FUNC_FLAVOR_FUNCTION);
+	id->SetType(func_t);
+
+	auto sc = current_scope();
+	std::vector<IDPtr> empty_inits;
+	StmtPtr stmts_p{NewRef{}, stmts};
+	auto sf = make_intrusive<ScriptFunc>(id, stmts_p, empty_inits,
+						sc->Length(), 0);
+
+	funcs.emplace_back(sf, ScopePtr{NewRef{}, sc}, stmts_p);
+
+	return &funcs.back();
+	}
+
 static void check_env_opt(const char* opt, bool& opt_flag)
 	{
 	if ( getenv(opt) )

src/script_opt/ScriptOpt.h

@@ -96,6 +96,11 @@ extern std::unordered_set<const Func*> non_recursive_funcs;
 // Analyze a given function for optimization.
 extern void analyze_func(ScriptFuncPtr f);
 
+// Analyze the given top-level statement(s) for optimization.  Returns
+// a pointer to a FuncInfo for an argument-less quasi-function that can
+// be Invoked, or its body executed directly, to execute the statements.
+extern const FuncInfo* analyze_global_stmts(Stmt* stmts);
+
 // Analyze all of the parsed scripts collectively for optimization.
 extern void analyze_scripts();
 

src/zeek-setup.cc

@@ -752,6 +752,8 @@ SetupResult setup(int argc, char** argv, Options* zopts)
 			}
 		}
 
+	auto init_stmts = stmts ? analyze_global_stmts(stmts) : nullptr;
+
 	analyze_scripts();
 
 	if ( analysis_options.report_recursive )
@@ -838,15 +840,15 @@ SetupResult setup(int argc, char** argv, Options* zopts)
 	// cause more severe problems.
 	ZEEK_LSAN_ENABLE();
 
-	if ( stmts )
+	if ( init_stmts )
 		{
 		StmtFlowType flow;
-		Frame f(current_scope()->Length(), nullptr, nullptr);
+		Frame f(init_stmts->Scope()->Length(), nullptr, nullptr);
 		g_frame_stack.push_back(&f);
 
 		try
 			{
-			stmts->Exec(&f, flow);
+			init_stmts->Body()->Exec(&f, flow);
 			}
 		catch ( InterpreterException& )
 			{