re PR c++/91974 (function not sequenced before function argument)

	PR c++/91974
	* cp-gimplify.c (cp_gimplify_expr) <case CALL_EXPR>: For
	-fstrong-eval-order ensure CALL_EXPR_FN side-effects are evaluated
	before any arguments.  Additionally, ensure CALL_EXPR_FN that isn't
	invariant nor OBJ_TYPE_REF nor SSA_NAME is forced into a temporary.

	* g++.dg/cpp1z/eval-order5.C: New test.

From-SVN: r276562

gcc/cp/ChangeLog

+2019-10-04  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/91974
+	* cp-gimplify.c (cp_gimplify_expr) <case CALL_EXPR>: For
+	-fstrong-eval-order ensure CALL_EXPR_FN side-effects are evaluated
+	before any arguments.  Additionally, ensure CALL_EXPR_FN that isn't
+	invariant nor OBJ_TYPE_REF nor SSA_NAME is forced into a temporary.
+
 2019-10-03  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	* init.c (build_new): Use cp_expr_loc_or_input_loc in two places.

gcc/cp/cp-gimplify.c

@@ -818,6 +818,21 @@ cp_gimplify_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p)
 
     case CALL_EXPR:
       ret = GS_OK;
+      if (flag_strong_eval_order == 2
+	  && CALL_EXPR_FN (*expr_p)
+	  && cp_get_callee_fndecl_nofold (*expr_p) == NULL_TREE)
+	{
+	  enum gimplify_status t
+	    = gimplify_expr (&CALL_EXPR_FN (*expr_p), pre_p, NULL,
+			     is_gimple_call_addr, fb_rvalue);
+	  if (t == GS_ERROR)
+	    ret = GS_ERROR;
+	  else if (is_gimple_variable (CALL_EXPR_FN (*expr_p))
+		   && TREE_CODE (CALL_EXPR_FN (*expr_p)) != SSA_NAME)
+	    CALL_EXPR_FN (*expr_p)
+	      = get_initialized_tmp_var (CALL_EXPR_FN (*expr_p), pre_p,
+					 NULL);
+	}
       if (!CALL_EXPR_FN (*expr_p))
 	/* Internal function call.  */;
       else if (CALL_EXPR_REVERSE_ARGS (*expr_p))

gcc/testsuite/ChangeLog

+2019-10-04  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/91974
+	* g++.dg/cpp1z/eval-order5.C: New test.
+
 2019-10-03  Steven G. Kargl  <kargl@gcc.gnu.org>
 
 	PR fortran/91497

gcc/testsuite/g++.dg/cpp1z/eval-order5.C

+// PR c++/91974
+// { dg-do run }
+// { dg-options "-fstrong-eval-order" }
+
+extern "C" void abort ();
+
+bool ok = false;
+
+void
+foo (int x)
+{
+  if (x != 0)
+    abort ();
+  ok = true;
+}
+
+void
+bar (int)
+{
+  abort ();
+}
+
+int
+main ()
+{
+  typedef void (*T) (int);
+  T fn = foo;
+  fn ((fn = bar, 0));
+  if (fn != bar || !ok)
+    abort ();
+}