From 5328cad24f7460a39b2def12bb9b62be36c92a54 Mon Sep 17 00:00:00 2001
From: Martin Sebor <msebor@redhat.com>
Date: Fri, 4 Jun 2021 11:21:51 -0600
Subject: [PATCH] PR c/100783 - ICE on -Wnonnull and erroneous type

gcc/c-family/ChangeLog:

	PR c/100783
	* c-attribs.c (positional_argument): Bail on erroneous types.

gcc/c/ChangeLog:

	PR c/100783
	* c-objc-common.c (print_type): Handle erroneous types.

gcc/testsuite/ChangeLog:

	PR c/100783
	* gcc.dg/nonnull-6.c: New test.
---
 gcc/c-family/c-attribs.c         |  3 +++
 gcc/c/c-objc-common.c            |  6 ++++++
 gcc/testsuite/gcc.dg/nonnull-6.c | 15 +++++++++++++++
 3 files changed, 24 insertions(+)
 create mode 100644 gcc/testsuite/gcc.dg/nonnull-6.c

diff --git a/gcc/c-family/c-attribs.c b/gcc/c-family/c-attribs.c
index 156f7b3..42026a8 100644
--- a/gcc/c-family/c-attribs.c
+++ b/gcc/c-family/c-attribs.c
@@ -698,6 +698,9 @@ positional_argument (const_tree fntype, const_tree atname, tree pos,
 
   if (tree argtype = type_argument_type (fntype, ipos))
     {
+      if (argtype == error_mark_node)
+	return NULL_TREE;
+
       if (flags & POSARG_ELLIPSIS)
 	{
 	  if (argno < 1)
diff --git a/gcc/c/c-objc-common.c b/gcc/c/c-objc-common.c
index a68249d..b945de1 100644
--- a/gcc/c/c-objc-common.c
+++ b/gcc/c/c-objc-common.c
@@ -185,6 +185,12 @@ get_aka_type (tree type)
 static void
 print_type (c_pretty_printer *cpp, tree t, bool *quoted)
 {
+  if (t == error_mark_node)
+    {
+      pp_string (cpp, _("{erroneous}"));
+      return;
+    }
+
   gcc_assert (TYPE_P (t));
   struct obstack *ob = pp_buffer (cpp)->obstack;
   char *p = (char *) obstack_base (ob);
diff --git a/gcc/testsuite/gcc.dg/nonnull-6.c b/gcc/testsuite/gcc.dg/nonnull-6.c
new file mode 100644
index 0000000..8f36870
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/nonnull-6.c
@@ -0,0 +1,15 @@
+/* PR c/100783 - ICE on -Wnonnull and erroneous type
+   { dg-do compile }
+   { dg-options "-Wall" } */
+
+__attribute__((nonnull (1))) void
+f1 (char[][n]);                         // { dg-error "undeclared" }
+
+__attribute__((nonnull (2))) void
+f2 (int n, char[n][m]);                 // { dg-error "undeclared" }
+
+__attribute__((nonnull (1))) void
+f3 (char[*][n]);                        // { dg-error "undeclared" }
+
+__attribute__((nonnull (1))) void
+f4 (char[f1]);                          // { dg-error "size" }
-- 
2.7.4