LIST_HEAD as a local variable is a C99ism.

Address of a variable whose storage duration is `auto` is _not_ a
compile time constant, according to ISO 9899 section 6.4.
LIST_HEAD takes such thing.  You can't use it to declare local
variables.

Interestingly, address of a static variable _is_ a compile time
constant.  So a declaration like `static LIST_HEAD..` is
completely legal even in C90.

In C99 and newer, this is not a constraint violation.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63312 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

2 files changed, 4 insertions, 2 deletions

diff --git a/io.c b/io.c
index c0457731d0..6a0d7114d2 100644
--- a/io.c
+++ b/io.c
@@ -4670,7 +4670,8 @@ io_close_fptr(VALUE io)
     rb_io_t *fptr;
     VALUE write_io;
     rb_io_t *write_fptr;
-    LIST_HEAD(busy);
+    struct list_head busy;
+    busy.n.next = busy.n.prev = &busy.n;
 
     write_io = GetWriteIO(io);
     if (io != write_io) {
diff --git a/thread.c b/thread.c
index 00d8b43986..7ca6625d7c 100644
--- a/thread.c
+++ b/thread.c
@@ -2288,7 +2288,8 @@ rb_notify_fd_close(int fd, struct list_head *busy)
 void
 rb_thread_fd_close(int fd)
 {
-    LIST_HEAD(busy);
+    struct list_head busy;
+    busy.n.next = busy.n.prev = &busy.n;
 
     if (rb_notify_fd_close(fd, &busy)) {
 	do rb_thread_schedule(); while (!list_empty(&busy));