From: Jakub Jelinek <jakub@redhat.com>
Date: Wed, 3 Mar 2021 08:55:19 +0000 (+0100)
Subject: c-family: Avoid ICE on va_arg [PR99324]
X-Git-Tag: upstream/12.2.0~9481
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=ba09d11a9d0ae2382bab715b102a7746d20dea6d;p=platform%2Fupstream%2Fgcc.git

c-family: Avoid ICE on va_arg [PR99324]

build_va_arg calls the middle-end mark_addressable, which e.g. requires that
cfun is non-NULL.  The following patch calls instead c_common_mark_addressable_vec
which is the c-family variant similarly to the FE c_mark_addressable and
cxx_mark_addressable, except that it doesn't error on addresses of register
variables.  As the taking of the address is artificial for the .VA_ARG
ifn and when that is lowered goes away, it is similar case to the vector
subscripting for which c_common_mark_addressable_vec has been added.

2021-03-03  Jakub Jelinek  <jakub@redhat.com>

	PR c/99324
	* c-common.c (build_va_arg): Call c_common_mark_addressable_vec
	instead of mark_addressable.  Fix a comment typo -
	neutrallly -> neutrally.

	* gcc.c-torture/compile/pr99324.c: New test.
---

diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
index 088626d..d227686 100644
--- a/gcc/c-family/c-common.c
+++ b/gcc/c-family/c-common.c
@@ -4553,7 +4553,7 @@ build_va_arg (location_t loc, tree expr, tree type)
       if (canon_va_type == NULL_TREE)
 	error_at (loc, "first argument to %<va_arg%> not of type %<va_list%>");
 
-      /* Let's handle things neutrallly, if expr:
+      /* Let's handle things neutrally, if expr:
 	 - has undeclared type, or
 	 - is not an va_list type.  */
       return build_va_arg_1 (loc, type, error_mark_node);
@@ -4565,7 +4565,7 @@ build_va_arg (location_t loc, tree expr, tree type)
 
       /* Take the address, to get '&ap'.  Note that &ap is not a va_list
 	 type.  */
-      mark_addressable (expr);
+      c_common_mark_addressable_vec (expr);
       expr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (expr)), expr);
 
       return build_va_arg_1 (loc, type, expr);
@@ -4627,7 +4627,7 @@ build_va_arg (location_t loc, tree expr, tree type)
 
       /* Take the address, to get '&ap'.  Make sure it's a pointer to array
 	 elem type.  */
-      mark_addressable (expr);
+      c_common_mark_addressable_vec (expr);
       expr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (canon_va_type)),
 		     expr);
 
diff --git a/gcc/testsuite/gcc.c-torture/compile/pr99324.c b/gcc/testsuite/gcc.c-torture/compile/pr99324.c
new file mode 100644
index 0000000..7a41e5c
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr99324.c
@@ -0,0 +1,19 @@
+/* PR c/99324 */
+
+#include <stdarg.h>
+
+int
+foo (int x, ...)
+{
+  va_list a;
+  va_start (a, x);
+  int b[6] = {};
+  int bar (c)
+    int c[1][va_arg (a, int)];
+  {
+    return sizeof c[0];
+  }
+  int r = bar (b);
+  va_end (a);
+  return r;
+}