[gcc/devel/ranger] c++: ICE with ptr_plus_expr

[Aldy Hernandez]

https://gcc.gnu.org/g:f2c8be187e8eb061e44166ac41646285821be6a6

commit f2c8be187e8eb061e44166ac41646285821be6a6
Author: Nathan Sidwell <nathan@acm.org>
Date:   Tue Apr 21 06:46:42 2020 -0700

    c++: ICE with ptr_plus_expr
    
    An ICE on darwin, when a SFINAE-context substitution produced
    error_mark_node foo an operand of a POINTER_PLUS_EXPR.
    fold_build_pointer_plus is unprepared to deal with that, so we need to
    check earlier.  We had no luck reducing the testcase to something
    manageable.
    
            * pt.c (tsubst_copy_and_build) [POINTER_PLUS_EXPR]: Check for
            error_mark_node.

Diff:
---
 gcc/cp/ChangeLog | 11 ++++++++---
 gcc/cp/pt.c      |  4 ++++
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 5b2bff8c561..81647d40b68 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,8 @@
+2020-04-21  Nathan Sidwell  <nathan@acm.org>
+
+	* pt.c (tsubst_copy_and_build) [POINTER_PLUS_EXPR]: Check for
+	error_mark_node.
+
 2020-04-21 Iain Sandoe <iain@sandoe.co.uk>
 
 	PR c++/94661
@@ -38,13 +43,13 @@
 
 2020-04-20  Nathan Sidwell  <nathan@acm.org>
 
-	PR 94454 - tpl-tpl-parms are not canonicalizable types
+	PR c++/94454 - tpl-tpl-parms are not canonicalizable types
 	* pt.c (canonical_type_parameter): Assert not a tpl-tpl-parm.
 	(process_template_parm): tpl-tpl-parms are structural.
 	(rewrite_template_parm): Propagate structuralness.
 
-	PR 94454 - Expr pack expansion equality
-	* tree.c (cp_tree_equal): [TEMPLATE_ID_EXPR, default] Refactor.
+	PR c++/94454 - Expr pack expansion equality
+	* tree.c (cp_tree_equal) [TEMPLATE_ID_EXPR, default]: Refactor.
 	[EXPR_PACK_EXPANSION]: Add.
 
 	PR c++/94454 Template Argument Hashing
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index cd6392aca22..6f74c278c23 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -19409,7 +19409,11 @@ tsubst_copy_and_build (tree t,
     case POINTER_PLUS_EXPR:
       {
 	tree op0 = RECUR (TREE_OPERAND (t, 0));
+	if (op0 == error_mark_node)
+	  RETURN (error_mark_node);
 	tree op1 = RECUR (TREE_OPERAND (t, 1));
+	if (op1 == error_mark_node)
+	  RETURN (error_mark_node);
 	RETURN (fold_build_pointer_plus (op0, op1));
       }