re PR debug/90574 ([gdb] gdb wrongly stopped at a breakpoint in an unexecuted line of code)

2019-06-07  Richard Biener  <rguenther@suse.de>

	PR debug/90574
	* tree-cfg.c (stmt_starts_bb_p): Split blocks at labels
	that appear after user labels.

	* gcc.misc-tests/gcov-pr90574-1.c: New testcase.
	* gcc.misc-tests/gcov-pr90574-2.c: Likewise.

From-SVN: r272040

gcc/ChangeLog

+2019-06-07  Richard Biener  <rguenther@suse.de>
+
+	PR debug/90574
+	* tree-cfg.c (stmt_starts_bb_p): Split blocks at labels
+	that appear after user labels.
+
 2019-06-07  Martin Liska  <mliska@suse.cz>
 
 	* cselib.c (cselib_init): Disable hash table

gcc/testsuite/ChangeLog

+2019-06-07  Richard Biener  <rguenther@suse.de>
+
+	PR debug/90574
+	* gcc.misc-tests/gcov-pr90574-1.c: New testcase.
+	* gcc.misc-tests/gcov-pr90574-2.c: Likewise.
+
 2019-06-07  Jan Hubicka  <hubicka@ucw.cz>
 
 	* gcc.dg/lto/alias-access-path-2.0.c: New testcase.

gcc/testsuite/gcc.misc-tests/gcov-pr90574-1.c

+/* { dg-options "-fprofile-arcs -ftest-coverage" } */
+/* { dg-do run { target native } } */
+
+int main(int argc, char **argv)
+{
+  if (argc == 0)
+    {
+      int *ptr;
+label:  /* count(#####) */
+	{
+	}
+    }
+  if (argc == 1)
+    {
+      __builtin_printf("hello\n");
+    }
+  return 0;
+}
+
+/* { dg-final { run-gcov gcov-pr90574-1.c } } */

gcc/testsuite/gcc.misc-tests/gcov-pr90574-2.c

+/* { dg-options "-fprofile-arcs -ftest-coverage" } */
+/* { dg-do run { target native } } */
+
+int main(int argc, char **argv)
+{
+  switch (argc)
+    {
+    case 0:
+      foo: /* count(#####) */
+    case 1:;
+    }
+  return 0;
+}
+
+/* { dg-final { run-gcov gcov-pr90574-2.c } } */

gcc/tree-cfg.c

@@ -2722,10 +2722,10 @@ stmt_starts_bb_p (gimple *stmt, gimple *prev_stmt)
 	  || FORCED_LABEL (gimple_label_label (label_stmt)))
 	return true;
 
-      if (prev_stmt && gimple_code (prev_stmt) == GIMPLE_LABEL)
+      if (glabel *plabel = safe_dyn_cast <glabel *> (prev_stmt))
 	{
-	  if (DECL_NONLOCAL (gimple_label_label (
-			       as_a <glabel *> (prev_stmt))))
+	  if (DECL_NONLOCAL (gimple_label_label (plabel))
+	      || !DECL_ARTIFICIAL (gimple_label_label (plabel)))
 	    return true;
 
 	  cfg_stats.num_merged_labels++;