export xfree() to Nim

libbacktrace.nim

@@ -42,7 +42,7 @@ proc getBacktrace*(): string {.noinline.} =
   result = newString(btLen)
   if btLen > 0:
     copyMem(addr(result[0]), bt, btLen)
-  c_free(bt)
+  xfree_backtrace_c(bt)
 
 when defined(nimStackTraceOverride):
   registerStackTraceOverride(getBacktrace)

libbacktrace_wrapper.c

@@ -46,7 +46,7 @@ static void *xmalloc(size_t size)
 	return res;
 }
 
-static void xfree(void *ptr)
+void xfree(void *ptr)
 {
 	if (ptr == NULL) {
 		fprintf(stderr, "BUG: xfree() received a NULL pointer.\n");

libbacktrace_wrapper.h

@@ -18,6 +18,8 @@ extern "C" {
 // The returned string needs to be freed by the caller.
 char *get_backtrace_c(void) __attribute__((noinline));
 
+void xfree(void *ptr);
+
 #ifdef __cplusplus
 } // extern "C"
 #endif

libbacktrace_wrapper.nim

@@ -13,3 +13,6 @@
 proc get_backtrace_c*(): cstring {.importc: "get_backtrace_c",
                               header: "libbacktrace_wrapper.h".}
 
+proc xfree_backtrace_c*(p: pointer) {.importc: "xfree",
+                              header: "libbacktrace_wrapper.h".}
+