gcov: dump in a static dtor instead of in an atexit handler

	PR gcov-profile/7970
	PR gcov-profile/16855
	PR gcov-profile/44779
	* g++.dg/gcov/pr16855.C: New test.
	* coverage.c (build_gcov_exit_decl): New function.
	(coverage_obj_init): Call the function and generate __gcov_exit
	destructor.
	* doc/gcov.texi: Document when __gcov_exit function is called.
	* libgcov-driver.c (__gcov_init): Do not register a atexit
	handler.
	(__gcov_exit): Rename from gcov_exit.
	* libgcov.h (__gcov_exit): Declare.

From-SVN: r240529

1 files changed, 25 insertions, 2 deletions

diff --git a/gcc/coverage.c b/gcc/coverage.c
index 30cdc69..0b8c0b3 100644
--- a/gcc/coverage.c
+++ b/gcc/coverage.c
@@ -1055,8 +1055,30 @@ build_init_ctor (tree gcov_info_type)
   stmt = build_call_expr (init_fn, 1, stmt);
   append_to_statement_list (stmt, &ctor);
 
-  /* Generate a constructor to run it.  */
-  cgraph_build_static_cdtor ('I', ctor, DEFAULT_INIT_PRIORITY);
+  /* Generate a constructor to run it (with priority 99).  */
+  cgraph_build_static_cdtor ('I', ctor, DEFAULT_INIT_PRIORITY - 1);
+}
+
+/* Generate the destructor function to call __gcov_exit.  */
+
+static void
+build_gcov_exit_decl (void)
+{
+  tree init_fn = build_function_type_list (void_type_node, void_type_node,
+					   NULL);
+  init_fn = build_decl (BUILTINS_LOCATION, FUNCTION_DECL,
+			get_identifier ("__gcov_exit"), init_fn);
+  TREE_PUBLIC (init_fn) = 1;
+  DECL_EXTERNAL (init_fn) = 1;
+  DECL_ASSEMBLER_NAME (init_fn);
+
+  /* Generate a call to __gcov_exit ().  */
+  tree dtor = NULL;
+  tree stmt = build_call_expr (init_fn, 0);
+  append_to_statement_list (stmt, &dtor);
+
+  /* Generate a destructor to run it (with priority 99).  */
+  cgraph_build_static_cdtor ('D', dtor, DEFAULT_INIT_PRIORITY - 1);
 }
 
 /* Create the gcov_info types and object.  Generate the constructor
@@ -1114,6 +1136,7 @@ coverage_obj_init (void)
   DECL_NAME (gcov_info_var) = get_identifier (name_buf);
 
   build_init_ctor (gcov_info_type);
+  build_gcov_exit_decl ();
 
   return true;
 }