more C warnings fixed

vlib/builtin/builtin.v

@@ -17,17 +17,19 @@ fn on_panic(f fn (int) int) {
 	// TODO
 }
 
+fn C.backtrace(voidptr, int) int
+
 pub fn print_backtrace_skipping_top_frames(skipframes int) {
 	$if mac {
 		buffer := [100]byteptr
-		nr_ptrs := C.backtrace(buffer, 100)
-		C.backtrace_symbols_fd(&buffer[skipframes], nr_ptrs-skipframes, 1)
+		nr_ptrs := C.backtrace(*voidptr(buffer), 100)
+		C.backtrace_symbols_fd(*voidptr(&buffer[skipframes]), nr_ptrs-skipframes, 1)
 		return
 	}
 	$if linux {
 		if C.backtrace_symbols_fd != 0 {
 			buffer := [100]byteptr
-			nr_ptrs := C.backtrace(buffer, 100)
+			nr_ptrs := C.backtrace(*voidptr(buffer), 100)
 			C.backtrace_symbols_fd(&buffer[skipframes], nr_ptrs-skipframes, 1)
 			return
 		}else{

vlib/builtin/int.v

@@ -9,20 +9,20 @@ module builtin
 
 pub fn (d f64) str() string {
 	buf := malloc(sizeof(double) * 5 + 1)// TODO
-	C.sprintf(buf, '%f', d)
-	return tos(buf, strlen(buf))
+	C.sprintf(*char(buf), '%f', d)
+	return tos(buf, vstrlen(buf))
 }
 
 pub fn (d f32) str() string {
 	buf := malloc(sizeof(double) * 5 + 1)// TODO
-	C.sprintf(buf, '%f', d)
-	return tos(buf, strlen(buf))
+	C.sprintf(*char(buf), '%f', d)
+	return tos(buf, vstrlen(buf))
 }
 
 pub fn ptr_str(ptr voidptr) string {
 	buf := malloc(sizeof(double) * 5 + 1)// TODO
-	C.sprintf(buf, '%p', ptr)
-	return tos(buf, strlen(buf))
+	C.sprintf(*char(buf), '%p', ptr)
+	return tos(buf, vstrlen(buf))
 }
 
 // compare floats using C epsilon
@@ -160,7 +160,7 @@ pub fn (n int) hex() string {
 		11
 	}
 	hex := malloc(len) // 0x + \n
-	count := int(C.sprintf(hex, '0x%x', n))
+	count := int(C.sprintf(*char(hex), '0x%x', n))
 	return tos(hex, count)
 }
 
@@ -171,7 +171,7 @@ pub fn (n i64) hex() string {
 		19
 	}
 	hex := malloc(len)
-	count := int(C.sprintf(hex, '0x%x', n))
+	count := int(C.sprintf(*char(hex), '0x%llx', n))
 	return tos(hex, count)
 }
 

vlib/builtin/map.v

@@ -211,7 +211,7 @@ pub fn (m mut map) delete(key string) {
 	m.size--
 }
 
-pub fn (m map) exists(key string) bool {
+pub fn (m map) exists(key string) {
 	panic('map.exists(key) was removed from the language. Use `key in map` instead.')
 }
 

vlib/builtin/string.v

@@ -22,6 +22,10 @@ pub:
 // For C strings only
 fn C.strlen(s byteptr) int
 
+pub fn vstrlen(s byteptr) int {
+	return C.strlen(*char(s))
+}	
+
 fn todo() { }
 
 // Converts a C string to a V string.
@@ -50,7 +54,7 @@ fn tos2(s byteptr) string {
 	if isnil(s) {
 		panic('tos2: nil string')
 	}
-	len := C.strlen(s)
+	len := vstrlen(s)
 	res := tos(s, len)
 	return res
 }

vlib/builtin/utf8.v

@@ -4,8 +4,8 @@
 
 module builtin
 
-pub fn utf8_char_len(b byte) int { 
-	return (( 0xe5000000 >> (( b >> 3 ) & 0x1e )) & 3 ) + 1 
+pub fn utf8_char_len(b byte) int {
+	return (( 0xe5000000 >> (( b >> 3 ) & 0x1e )) & 3 ) + 1
 }
 
 // Convert utf32 to utf8
@@ -157,12 +157,11 @@ fn utf8_len(c byte) int {
 pub fn utf8_getchar() int {
   c := int(C.getchar())
   len := utf8_len(~c)
-
   if c < 0 {
     return 0
-  } else if (len == 0) {
+  } else if len == 0 {
     return c
-  } else if (len == 1) {
+  } else if len == 1 {
     return -1
   } else {
     mut uc := int(c & ((1 << (7 - len)) - 1))
@@ -171,7 +170,7 @@ pub fn utf8_getchar() int {
       if c2 != -1 && (c2 >> 6) == 2 {
         uc <<= 6
         uc |= int((c2 & 63))
-      }  else if (c2 == -1) {
+      }  else if c2 == -1 {
         return 0
       } else {
         return -1