Create a coverage initialization function.

This function replaces the call of `atexit' from being generated in the compile
units. Basically, it registers the "writeout" and "flush" functions (if
present). It will generate calls to the `atexit' function for cleanups and final
writeout functions, but only once. This is better than checking for `main',
because a library may not have a `main' function in it.
<rdar://problem/12439551>

llvm-svn: 177578

2 files changed, 21 insertions, 1 deletions

diff --git a/compiler-rt/SDKs/darwin/usr/include/stdlib.h b/compiler-rt/SDKs/darwin/usr/include/stdlib.h
index c18c2e49a32..7c973dcc610 100644
--- a/compiler-rt/SDKs/darwin/usr/include/stdlib.h
+++ b/compiler-rt/SDKs/darwin/usr/include/stdlib.h
@@ -22,6 +22,7 @@
 typedef __SIZE_TYPE__ size_t;
 
 void abort(void) __attribute__((__noreturn__));
+int atexit(void (*)(void));
 int atoi(const char *);
 void free(void *);
 char *getenv(const char *);
diff --git a/compiler-rt/lib/profile/GCDAProfiling.c b/compiler-rt/lib/profile/GCDAProfiling.c
index bca25536755..86f68f58a9c 100644
--- a/compiler-rt/lib/profile/GCDAProfiling.c
+++ b/compiler-rt/lib/profile/GCDAProfiling.c
@@ -331,7 +331,7 @@ void llvm_register_writeout_function(writeout_fn fn) {
   }
 }
 
-void __llvm_writeout_files() {
+void llvm_writeout_files() {
   struct writeout_fn_node *curr = writeout_fn_head;
 
   while (curr) {
@@ -381,3 +381,22 @@ void llvm_delete_flush_function_list() {
 
   flush_fn_head = flush_fn_tail = NULL;
 }
+
+void llvm_gcov_init(writeout_fn wfn, flush_fn ffn) {
+  static int atexit_ran = 0;
+
+  if (wfn)
+    llvm_register_writeout_function(wfn);
+
+  if (ffn)
+    llvm_register_flush_function(ffn);
+
+  if (atexit_ran == 0) {
+    atexit_ran = 1;
+
+    /* Make sure we write out the data and delete the data structures. */
+    atexit(llvm_delete_flush_function_list);
+    atexit(llvm_delete_writeout_function_list);
+    atexit(llvm_writeout_files);
+  }
+}