compiler: more memory logic + replace "cur_fn &Fn" with "cur_fn Fn"

vlib/builtin/builtin.v

@@ -99,14 +99,14 @@ pub fn print(s string) {
 }
 
 __global total_m i64 = 0
-//__global nr_mallocs int = 0 
+//__global nr_mallocs int = 0
 pub fn malloc(n int) byteptr {
 	if n < 0 {
 		panic('malloc(<0)')
 	}
-	//nr_mallocs++ 
-/* 
-TODO 
+	//nr_mallocs++
+/*
+TODO
 #ifdef VPLAY
 	if n > 10000 {
 		panic('allocating more than 10 KB is not allowed in the playground')
@@ -117,7 +117,7 @@ TODO
 	println('\n\n\nmalloc($n) total=$total_m')
 	print_backtrace()
 #endif
-*/ 
+*/
 	ptr := C.malloc(n)
 	if isnil(ptr) {
 		panic('malloc($n) failed')
@@ -141,5 +141,9 @@ fn memdup(src voidptr, sz int) voidptr {
 	return C.memcpy(mem, src, sz)
 }
 
+fn v_ptr_free(ptr voidptr) {
+	C.free(ptr)
+}	
+
 
 

vlib/builtin/map.v

@@ -236,7 +236,24 @@ pub fn (m map) print() {
 	println('>>>>>>>>>>')
 }
 
-pub fn (m map) free() {
+fn (n mut mapnode) free() {
+	if n.val != 0 {
+		free(n.val)
+	}	
+	if n.left != 0 {
+		n.left.free()
+	}	
+	if n.right != 0 {
+		n.right.free()
+	}	
+	free(n)
+}
+
+pub fn (m mut map) free() {
+	if m.root == 0 {
+		return
+	}	
+	m.root.free()
 	// C.free(m.table)
 	// C.free(m.keys_table)
 }

vlib/builtin/string.v

@@ -156,7 +156,7 @@ pub fn (s string) u64() u64 {
 
 // ==
 fn (s string) eq(a string) bool {
-	if isnil(s.str) {
+	if isnil(s.str) { // should never happen
 		panic('string.eq(): nil string')
 	}
 	if s.len != a.len {

vlib/os/os.v

@@ -289,8 +289,7 @@ pub fn (f File) close() {
 }
 
 // system starts the specified command, waits for it to complete, and returns its code.
-
-fn popen(path string) &FILE {
+fn popen(path string) *C.FILE {
 	$if windows {
 		mode := 'rb'
 		wpath := path.to_wide()
@@ -302,7 +301,7 @@ fn popen(path string) &FILE {
 	}
 }
 
-fn pclose(f &FILE) int {
+fn pclose(f *C.FILE) int {
 	$if windows {
 		return C._pclose(f)
 	}