GCOVFlush-compiler-rt.patch

Index: lib/profile/GCDAProfiling.c
===================================================================
--- lib/profile/GCDAProfiling.c  (revision 173961)
+++ lib/profile/GCDAProfiling.c	(working copy)
@@ -269,6 +269,9 @@
   for (i = 0; i < num_counters; ++i)
     fprintf(stderr, "llvmgcda:   %llu\n", (unsigned long long)counters[i]);
 #endif
+
+  for (i = 0; i < num_counters; ++i)
+    counters[i] = 0;
 }
 
 void llvm_gcda_end_file() {
@@ -282,3 +285,34 @@
   fprintf(stderr, "llvmgcda: -----\n");
 #endif
 }
+
+struct llvm_gcda_list {
+  struct llvm_gcda_list *next;      /* next in list */
+  void (*fn_ptr)(void);     /* function pointer */
+};
+
+static struct llvm_gcda_list *__llvm_gcda_list = NULL; /* points to head of LIFO stack */
+
+void __llvm_gcda_register(void (*func)(void)) {
+  struct llvm_gcda_list *p = malloc(sizeof(*p));
+
+  if (__llvm_gcda_list == NULL) {
+    __llvm_gcda_list = malloc(sizeof(*p));
+    __llvm_gcda_list->next = NULL;
+    __llvm_gcda_list->fn_ptr = NULL;
+  }
+
+  p->fn_ptr = func;
+  p->next = __llvm_gcda_list;
+  __llvm_gcda_list = p;
+}
+
+void __llvm_gcov_flush() {
+  struct llvm_gcda_list *p = __llvm_gcda_list;
+
+  while (p->next != NULL) {
+    if (p->fn_ptr)
+      p->fn_ptr();
+    p = p->next;
+  }
+}
\ No newline at end of file

GCOVFlush-llvm.patch

Index: lib/Transforms/Instrumentation/GCOVProfiling.cpp
===================================================================
--- lib/Transforms/Instrumentation/GCOVProfiling.cpp  (revision 173961)
+++ lib/Transforms/Instrumentation/GCOVProfiling.cpp	(working copy)
@@ -700,6 +700,12 @@
                           PointerType::get(FTy, 0), false);
   Constant *AtExitFn = M->getOrInsertFunction("atexit", FTy);
   Builder.CreateCall(AtExitFn, WriteoutF);
+
+  // Register the write function with the flush utility so its possible to
+  // flush the gcov data before atexit as well.
+  Constant *GcdaRegisterFn = M->getOrInsertFunction("__llvm_gcda_register",
+                                                    FTy);
+  Builder.CreateCall(GcdaRegisterFn, WriteoutF);
   Builder.CreateRetVoid();
 
   appendToGlobalCtors(*M, F, 0);