From: Jakub Jelinek <jakub@redhat.com>
Date: Wed, 3 Jan 2018 12:16:13 +0000 (+0100)
Subject: re PR c++/83634 (ICE in useless_type_conversion_p, at gimple-expr.c:86)
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=19c37faad10950f693872a4be018cfd9bc81804a;p=gcc.git

re PR c++/83634 (ICE in useless_type_conversion_p, at gimple-expr.c:86)

	PR c++/83634
	* cp-gimplify.c (cp_fold) <case NOP_EXPR>: If the operand folds to
	error_mark_node, return error_mark_node.

	* g++.dg/parse/pr83634.C: New test.

From-SVN: r256174
---

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 750a9a8f94f..9dfb293e7f3 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,9 @@
 2018-01-03  Jakub Jelinek  <jakub@redhat.com>
 
+	PR c++/83634
+	* cp-gimplify.c (cp_fold) <case NOP_EXPR>: If the operand folds to
+	error_mark_node, return error_mark_node.
+
 	Update copyright years.
 
 2018-01-02  Jakub Jelinek  <jakub@redhat.com>
diff --git a/gcc/cp/cp-gimplify.c b/gcc/cp/cp-gimplify.c
index 4f607289539..c090ee7fcbd 100644
--- a/gcc/cp/cp-gimplify.c
+++ b/gcc/cp/cp-gimplify.c
@@ -2112,7 +2112,20 @@ cp_fold (tree x)
     case NON_LVALUE_EXPR:
 
       if (VOID_TYPE_P (TREE_TYPE (x)))
-	return x;
+	{
+	  /* This is just to make sure we don't end up with casts to
+	     void from error_mark_node.  If we just return x, then
+	     cp_fold_r might fold the operand into error_mark_node and
+	     leave the conversion in the IR.  STRIP_USELESS_TYPE_CONVERSION
+	     during gimplification doesn't like such casts.
+	     Don't create a new tree if op0 != TREE_OPERAND (x, 0), the
+	     folding of the operand should be in the caches and if in cp_fold_r
+	     it will modify it in place.  */
+	  op0 = cp_fold (TREE_OPERAND (x, 0));
+	  if (op0 == error_mark_node)
+	    x = error_mark_node;
+	  break;
+	}
 
       loc = EXPR_LOCATION (x);
       op0 = cp_fold_maybe_rvalue (TREE_OPERAND (x, 0), rval_ops);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 822c29d640d..cff788b6a92 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2018-01-03  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/83634
+	* g++.dg/parse/pr83634.C: New test.
+
 2018-01-03  Thomas Koenig  <tkoenig@gcc.gnu.org>
 
 	PR fortran/83664
diff --git a/gcc/testsuite/g++.dg/parse/pr83634.C b/gcc/testsuite/g++.dg/parse/pr83634.C
new file mode 100644
index 00000000000..70a396eb421
--- /dev/null
+++ b/gcc/testsuite/g++.dg/parse/pr83634.C
@@ -0,0 +1,11 @@
+// PR c++/83634
+// { dg-do compile }
+
+void
+foo ()
+{
+  const int x = fn ();		// { dg-error "was not declared in this scope" }
+  short n;
+  for (n = x; n < 100; ++n)
+    ;
+}