diff --git a/vlib/builtin/builtin.v b/vlib/builtin/builtin.v
index 50e60a35dc..0683d85cf6 100644
--- a/vlib/builtin/builtin.v
+++ b/vlib/builtin/builtin.v
@@ -30,8 +30,6 @@ 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
diff --git a/vlib/builtin/cdefs.v b/vlib/builtin/cdefs.v
index 697475b586..ba280e73bc 100644
--- a/vlib/builtin/cdefs.v
+++ b/vlib/builtin/cdefs.v
@@ -1,5 +1,7 @@
 module builtin
 
+fn backtrace(a voidptr, b int) int
+
 fn C.memcpy(byteptr, byteptr, int)
 fn C.memmove(byteptr, byteptr, int)
 //fn C.malloc(int) byteptr
@@ -8,6 +10,12 @@ fn C.realloc(a byteptr, b int) byteptr
 fn C.qsort(voidptr, int, int, voidptr)
 
 fn C.sprintf(a ...voidptr) byteptr
+fn C.strlen(s byteptr) int
+
+
+
+fn backtrace_symbols_fd(voidptr, int, int)
+
 
 
 // Windows
diff --git a/vlib/builtin/string.v b/vlib/builtin/string.v
index e3b8691048..bb51dfb8e5 100644
--- a/vlib/builtin/string.v
+++ b/vlib/builtin/string.v
@@ -58,15 +58,10 @@ pub:
 	len   int
 }
 
-// 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.
 // String data is reused, not copied.
 pub fn tos(s byteptr, len int) string {
diff --git a/vlib/compiler/cheaders.v b/vlib/compiler/cheaders.v
index c1df0d850b..47404d44ef 100644
--- a/vlib/compiler/cheaders.v
+++ b/vlib/compiler/cheaders.v
@@ -21,13 +21,14 @@ CommonCHeaders = '
 
 #ifdef __APPLE__
 #include <libproc.h> // proc_pidpath
-#include <execinfo.h> // backtrace and backtrace_symbols_fd
+//#include <execinfo.h> // backtrace and backtrace_symbols_fd
 #endif
 
 #ifdef __linux__
-#ifndef __BIONIC__
-#include <execinfo.h> // backtrace and backtrace_symbols_fd
-#endif
+//#if !defined(__BIONIC__) && !defined(__GNUC_PREREQ)
+//#include <execinfo.h> // backtrace and backtrace_symbols_fd
+//#endif
+
 #pragma weak backtrace
 #pragma weak backtrace_symbols_fd
 #endif
diff --git a/vlib/compiler/fn.v b/vlib/compiler/fn.v
index 6a408f5fab..58dcc55748 100644
--- a/vlib/compiler/fn.v
+++ b/vlib/compiler/fn.v
@@ -352,7 +352,7 @@ fn (p mut Parser) fn_decl() {
 	}
 	// Translated C code and .vh can have empty functions (just definitions)
 	is_fn_header := !is_c && !p.is_vh &&
-		(p.pref.translated || p.pref.is_test || p.is_vh) &&
+		//(p.pref.translated || p.pref.is_test || p.is_vh) &&
 		p.tok != .lcbr
 	if is_fn_header {
 		f.is_decl = true