optimal & fix file cmake

build-standalone-codex-5j6ZZh/CMakeFiles/CheckLibraryExists/CheckFunctionExists.cxx

@@ -0,0 +1,28 @@
+#ifdef CHECK_FUNCTION_EXISTS
+
+#  ifdef __cplusplus
+extern "C"
+#  endif
+  char
+  CHECK_FUNCTION_EXISTS(void);
+#  ifdef __CLASSIC_C__
+int main()
+{
+  int ac;
+  char* av[];
+#  else
+int main(int ac, char* av[])
+{
+#  endif
+  CHECK_FUNCTION_EXISTS();
+  if (ac > 1000) {
+    return *av[0];
+  }
+  return 0;
+}
+
+#else /* CHECK_FUNCTION_EXISTS */
+
+#  error "CHECK_FUNCTION_EXISTS has to specify the function"
+
+#endif /* CHECK_FUNCTION_EXISTS */