v2: enable compilation of short programs with no 'import os'

vlib/v/gen/cgen.v

@@ -665,10 +665,12 @@ fn (g mut Gen) gen_fn_decl(it ast.FnDecl) {
 	}
 	if is_main {
 		g.writeln('_vinit();')
-		if g.autofree {
-			g.writeln('free(_const_os__args.data); // empty, inited in _vinit()')
+		if g.is_importing_os() {
+			if g.autofree {
+				g.writeln('free(_const_os__args.data); // empty, inited in _vinit()')
+			}
+			g.writeln('_const_os__args = os__init_os_args(argc, (byteptr*)argv);')
 		}
-		g.writeln('_const_os__args = os__init_os_args(argc, (byteptr*)argv);')
 	}
 	g.stmts(it.stmts)
 	// ////////////
@@ -1794,7 +1796,10 @@ fn (g mut Gen) write_init_function() {
 	if g.autofree {
 		g.writeln('void _vcleanup() {')
 		g.writeln('puts("cleaning up...");')
-		g.writeln('free(_const_os__args.data);')
+		if g.is_importing_os() {
+			g.writeln('free(_const_os__args.data);')
+			g.writeln('string_free(_const_os__wd_at_startup);')
+		}
 		g.writeln('free(_const_strconv__ftoa__powers_of_10.data);')
 		g.writeln('}')
 	}
@@ -2318,3 +2323,7 @@ pub fn (g mut Gen) write_tests_main() {
 	}
 	g.writeln('return 0; }')
 }
+
+fn (g &Gen) is_importing_os() bool {
+	return 'os' in g.table.imports
+}

vlib/v/gen/cgen_test.v

@@ -62,9 +62,9 @@ fn compare_texts(a, b, path string) bool {
 		line_b := lines_b[i]
 		if line_a.trim_space() != line_b.trim_space() {
 			println('${path}: Got\n$a')
-			println('${term_fail} near line: ${i}')
-			println(term.red('actual  :${line_a}'))
-			println(term.red('expected:${line_b}'))
+			println('${path}:${i}: ${term_fail}')
+			println(term.bold(term.bright_yellow('actual  : ')) + line_a)
+			println(term.green('expected: ') + line_b)
 			println(lines_b[i + 1])
 			println(lines_b[i + 2])
 			// exit(1)

vlib/v/gen/tests/1.c

@@ -48,7 +48,6 @@ struct varg_int {
 //
 int main(int argc, char** argv) {
 	_vinit();
-	_const_os__args = os__init_os_args(argc, (byteptr*)argv);
 	int a = 10;
 	a++;
 	int negative = -a;

vlib/v/gen/tests/2.c

@@ -78,7 +78,6 @@ void end() {
 
 int main(int argc, char** argv) {
 	_vinit();
-	_const_os__args = os__init_os_args(argc, (byteptr*)argv);
 	return 0;
 }
 

vlib/v/gen/tests/3.c

@@ -64,7 +64,6 @@ void handle_expr(Expr e) {
 
 int main(int argc, char** argv) {
 	_vinit();
-	_const_os__args = os__init_os_args(argc, (byteptr*)argv);
 	User user = (User){
 		.age = 0,
 		.name = tos3(""),

vlib/v/gen/tests/4.c

@@ -24,7 +24,6 @@ int Bar_testa(Bar* b);
 
 int main(int argc, char** argv) {
 	_vinit();
-	_const_os__args = os__init_os_args(argc, (byteptr*)argv);
     Bar b = (Bar){
         .a = 122,
     };