plugin: record hits and misses to logfile

src/clang-hash.cc

@@ -10,6 +10,8 @@
 #include <utime.h>
 #include <sys/stat.h>
 #include <sys/types.h>
+#include <fcntl.h>
+
 
 
 using namespace clang;
@@ -48,6 +50,15 @@ static void link_object_file() {
         dst = objectfile_copy;
     }
 
+    // Record Events
+    if (getenv("CLANG_HASH_LOGFILE")) {
+        int fd = open(getenv("CLANG_HASH_LOGFILE"),
+                      O_APPEND | O_WRONLY | O_CREAT,
+                      0644);
+        write(fd, atexit_mode == ATEXIT_FROM_CACHE ? "H" : "M", 1);
+        close(fd);
+    }
+
     /* If destination exists, we have to unlink it. */
     struct stat dummy;
     if (stat(dst, &dummy) == 0) { // exists