builtin,os: use more precise C. declarations for C.fread, C.fwrite and C.qsort

vlib/builtin/cfns.c.v

@@ -17,7 +17,7 @@ fn C.free(ptr voidptr)
 
 fn C.exit(code int)
 
-fn C.qsort(voidptr, int, int, qsort_callback_func)
+fn C.qsort(base voidptr, items size_t, item_size size_t, cb qsort_callback_func)
 
 fn C.sprintf(a ...voidptr) int
 
@@ -59,7 +59,9 @@ fn C.fopen() voidptr
 
 fn C.fileno(voidptr) int
 
-fn C.fwrite() int
+fn C.fread(ptr voidptr, item_size size_t, items size_t, stream &C.FILE) size_t
+
+fn C.fwrite(ptr voidptr, item_size size_t, items size_t, stream &C.FILE) size_t
 
 fn C.fclose() int
 
@@ -96,8 +98,6 @@ fn C.rmdir() int
 
 fn C.chdir() int
 
-fn C.fread() int
-
 fn C.rewind() int
 
 fn C.stat(charptr) int

vlib/os/file.c.v

@@ -33,7 +33,7 @@ pub fn (mut f File) write(buf []byte) ?int {
 		}
 	}
 	*/
-	written := C.fwrite(buf.data, buf.len, 1, f.cfile)
+	written := int(C.fwrite(buf.data, buf.len, 1, f.cfile))
 	if written == 0 && buf.len != 0 {
 		return error('0 bytes written')
 	}
@@ -54,7 +54,7 @@ pub fn (mut f File) writeln(s string) ?int {
 	}
 	*/
 	// TODO perf
-	written := C.fwrite(s.str, s.len, 1, f.cfile)
+	written := int(C.fwrite(s.str, s.len, 1, f.cfile))
 	if written == 0 && s.len != 0 {
 		return error('0 bytes written')
 	}
@@ -70,7 +70,7 @@ pub fn (mut f File) write_string(s string) ?int {
 		return error('file is not opened')
 	}
 	// TODO perf
-	written := C.fwrite(s.str, s.len, 1, f.cfile)
+	written := int(C.fwrite(s.str, s.len, 1, f.cfile))
 	if written == 0 && s.len != 0 {
 		return error('0 bytes written')
 	}
@@ -80,18 +80,18 @@ pub fn (mut f File) write_string(s string) ?int {
 // write_to implements the RandomWriter interface
 pub fn (mut f File) write_to(pos int, buf []byte) ?int {
 	C.fseek(f.cfile, pos, C.SEEK_SET)
-	res := C.fwrite(buf.data, 1, buf.len, f.cfile)
+	res := int(C.fwrite(buf.data, 1, buf.len, f.cfile))
 	C.fseek(f.cfile, 0, C.SEEK_END)
 	return res
 }
 
 pub fn (mut f File) write_bytes(data voidptr, size int) int {
-	return C.fwrite(data, 1, size, f.cfile)
+	return int(C.fwrite(data, 1, size, f.cfile))
 }
 
 pub fn (mut f File) write_bytes_at(data voidptr, size int, pos int) int {
 	C.fseek(f.cfile, pos, C.SEEK_SET)
-	res := C.fwrite(data, 1, size, f.cfile)
+	res := int(C.fwrite(data, 1, size, f.cfile))
 	C.fseek(f.cfile, 0, C.SEEK_END)
 	return res
 }
@@ -123,7 +123,7 @@ pub fn (f &File) read_bytes_into(pos int, mut buf []byte) ?int {
 	C.fseek(f.cfile, pos, C.SEEK_SET)
 	// errno is only set if fread fails, so clear it first to tell
 	C.errno = 0
-	nbytes := C.fread(buf.data, 1, buf.len, f.cfile)
+	nbytes := int(C.fread(buf.data, 1, buf.len, f.cfile))
 	if C.errno != 0 {
 		return error(posix_get_error_msg(C.errno))
 	}
@@ -139,7 +139,7 @@ pub fn (f &File) read(mut buf []byte) ?int {
 		return 0
 	}
 	C.errno = 0
-	nbytes := C.fread(buf.data, 1, buf.len, f.cfile)
+	nbytes := int(C.fread(buf.data, 1, buf.len, f.cfile))
 	if C.errno != 0 {
 		return error(posix_get_error_msg(C.errno))
 	}
@@ -153,7 +153,7 @@ pub fn (f &File) read_at(pos int, mut buf []byte) ?int {
 	}
 	C.fseek(f.cfile, pos, C.SEEK_SET)
 	C.errno = 0
-	nbytes := C.fread(buf.data, 1, buf.len, f.cfile)
+	nbytes := int(C.fread(buf.data, 1, buf.len, f.cfile))
 	if C.errno != 0 {
 		return error(posix_get_error_msg(C.errno))
 	}

vlib/os/os_c.v

@@ -59,7 +59,7 @@ pub fn read_bytes(path string) ?[]byte {
 	}
 	C.rewind(fp)
 	mut res := []byte{len: fsize}
-	nr_read_elements := C.fread(res.data, fsize, 1, fp)
+	nr_read_elements := int(C.fread(res.data, fsize, 1, fp))
 	if nr_read_elements == 0 && fsize > 0 {
 		return error('fread failed')
 	}
@@ -88,7 +88,7 @@ pub fn read_file(path string) ?string {
 	C.rewind(fp)
 	unsafe {
 		mut str := malloc(fsize + 1)
-		nelements := C.fread(str, fsize, 1, fp)
+		nelements := int(C.fread(str, fsize, 1, fp))
 		if nelements == 0 && fsize > 0 {
 			free(str)
 			return error('fread failed')