option handling for new -u/-uu flag for reporting usage issues

src/Options.cc

@@ -93,6 +93,7 @@ void usage(const char* prog, int code)
 	fprintf(stderr, "    -r|--readfile <readfile>       | read from given tcpdump file (only one allowed, pass '-' as the filename to read from stdin)\n");
 	fprintf(stderr, "    -s|--rulefile <rulefile>       | read rules from given file\n");
 	fprintf(stderr, "    -t|--tracefile <tracefile>     | activate execution tracing\n");
+	fprintf(stderr, "    -u|--usage-issues              | find variable usage issues and exit; use -uu for deeper/more expensive analysis\n");
 	fprintf(stderr, "    -v|--version                   | print version and exit\n");
 	fprintf(stderr, "    -w|--writefile <writefile>     | write to given tcpdump file\n");
 #ifdef DEBUG
@@ -286,6 +287,7 @@ Options parse_cmdline(int argc, char** argv)
 		{"rulefile",		required_argument,	nullptr,	's'},
 		{"tracefile",		required_argument,	nullptr,	't'},
 		{"writefile",		required_argument,	nullptr,	'w'},
+		{"usage-issues",	no_argument,		nullptr,	'u'},
 		{"version",		no_argument,		nullptr,	'v'},
 		{"no-checksums",	no_argument,		nullptr,	'C'},
 		{"force-dns",		no_argument,		nullptr,	'F'},
@@ -322,7 +324,7 @@ Options parse_cmdline(int argc, char** argv)
 	};
 
 	char opts[256];
-	util::safe_strncpy(opts, "B:e:f:G:H:I:i:j::n:O:o:p:r:s:T:t:U:w:X:CDFNPQSWabdhv",
+	util::safe_strncpy(opts, "B:e:f:G:H:I:i:j::n:O:o:p:r:s:T:t:U:w:X:CDFNPQSWabdhuv",
 	                         sizeof(opts));
 
 #ifdef USE_PERFTOOLS_DEBUG
@@ -407,6 +409,9 @@ Options parse_cmdline(int argc, char** argv)
 		case 't':
 			rval.debug_script_tracing_file = optarg;
 			break;
+		case 'u':
+			++rval.analysis_options.usage_issues;
+			break;
 		case 'v':
 			rval.print_version = true;
 			break;

src/script_opt/ScriptOpt.cc

@@ -12,6 +12,8 @@
 namespace zeek::detail {
 
 
+AnalyOpt analysis_options;
+
 std::unordered_set<const Func*> non_recursive_funcs;
 
 // Tracks all of the loaded functions (including event handlers and hooks).
@@ -104,10 +106,8 @@ static void check_env_opt(const char* opt, bool& opt_flag)
 		opt_flag = true;
 	}
 
-void analyze_scripts(Options& opts)
+void analyze_scripts()
 	{
-	auto& analysis_options = opts.analysis_options;
-
 	static bool did_init = false;
 
 	if ( ! did_init )
@@ -116,6 +116,11 @@ void analyze_scripts(Options& opts)
 		check_env_opt("ZEEK_INLINE", analysis_options.inliner);
 		check_env_opt("ZEEK_XFORM", analysis_options.activate);
 
+		auto usage = getenv("ZEEK_USAGE_ISSUES");
+
+		if ( usage )
+			analysis_options.usage_issues = atoi(usage) > 1 ? 2 : 1;
+
 		if ( ! analysis_options.only_func )
 			{
 			auto zo = getenv("ZEEK_ONLY");
@@ -123,7 +128,8 @@ void analyze_scripts(Options& opts)
 				analysis_options.only_func = zo;
 			}
 
-		if ( analysis_options.only_func )
+		if ( analysis_options.only_func ||
+		     analysis_options.usage_issues > 0 )
 			analysis_options.activate = true;
 
 		did_init = true;

src/script_opt/ScriptOpt.h

@@ -36,8 +36,18 @@ struct AnalyOpt {
 	// If true, report which functions are directly and indirectly
 	// recursive, and exit.  Only germane if running the inliner.
 	bool report_recursive = false;
+
+	// If non-zero, looks for variables that are used-but-possibly-not-set,
+	// or set-but-not-used.
+	//
+	// If > 1, also reports on uses of uninitialized record fields and
+	// analyzes nested records in depth.  Warning: with the current
+	// data structures this greatly increases analysis time.
+	int usage_issues = 0;
 };
 
+extern AnalyOpt analysis_options;
+
 
 class ProfileFunc;
 
@@ -81,7 +91,7 @@ extern std::unordered_set<const Func*> non_recursive_funcs;
 extern void analyze_func(ScriptFuncPtr f);
 
 // Analyze all of the parsed scripts collectively for optimization.
-extern void analyze_scripts(Options& opts);
+extern void analyze_scripts();
 
 
 } // namespace zeek::detail

src/zeek-setup.cc

@@ -781,9 +781,11 @@ SetupResult setup(int argc, char** argv, Options* zopts)
 			}
 		}
 
-	analyze_scripts(options);
+	// Set up the global that facilitates access to analysis/optimization
+	// options from deep within some modules.
+	analysis_options = options.analysis_options;
 
-	auto& analysis_options = options.analysis_options;
+	analyze_scripts();
 
 	if ( analysis_options.report_recursive )
 		// This option is report-and-exit.