[Bug target/65729] [5 Regression] ICE (in prohibited_class_reg_set_mode_p, at lra-constraints.c) on arm-linux-gnueabihf

["jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65729

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Seems the ICE or successful compilation aren't the only thing gcc used to
produce here:

old - r218687 ok     
r218688 - r218759 error: inconsistent operand constraints in an ‘asm’   
r218760 - r220293 ok 
r220294 - latest internal compiler error: in prohibited_class_reg_set_mode_p,
at lra-constraints.c
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From: "mpolacek at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/65727] [4.8/4.9/5 Regression] Segfault With Decltype In Lambda Expression Used To Initialize Static Class Member
Date: Fri, 10 Apr 2015 09:04:00 -0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?ide727

--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Here, we're trying to build_x_indirect_ref for a NULL pointer, that is bad.
The reason is that here
 787       /* In a lambda, need to go through 'this' capture.  */
 788       tree lam = CLASSTYPE_LAMBDA_EXPR (current_class_type);
 789       tree cap = lambda_expr_this_capture (lam, add_capture_p);
 790       if (cap != error_mark_node)
 791         object = build_x_indirect_ref (EXPR_LOCATION (object), cap,
 792                                        RO_NULL, tf_warning_or_error);
lambda_expr_this_capture returns NULL: it's looking for 'this', but doesn't
find it.

The fix in r215478 [1] dealt with not finding 'this' by checking for
error_mark, but perhaps we should also check whether the capture is non-NULL:

--- a/gcc/cp/lambda.c
+++ b/gcc/cp/lambda.c
@@ -787,7 +787,7 @@ maybe_resolve_dummy (tree object, bool add_capture_p)
       /* In a lambda, need to go through 'this' capture.  */
       tree lam = CLASSTYPE_LAMBDA_EXPR (current_class_type);
       tree cap = lambda_expr_this_capture (lam, add_capture_p);
-      if (cap != error_mark_node)
+      if (cap && cap != error_mark_node)
        object = build_x_indirect_ref (EXPR_LOCATION (object), cap,
                                       RO_NULL, tf_warning_or_error);
     }

[1] https://gcc.gnu.org/ml/gcc-patches/2014-09/msg01878.html