Bump to m4 1.4.19

[platform/upstream/m4.git] / lib / c-stack.h

diff --git a/lib/c-stack.h b/lib/c-stack.h
index 5aadfb5..a9a8b13 100644 (file)
--- a/lib/c-stack.h
+++ b/lib/c-stack.h
@@ -1,6 +1,6 @@
 /* Stack overflow handling.
 
-   Copyright (C) 2002, 2004, 2008-2011 Free Software Foundation, Inc.
+   Copyright (C) 2002, 2004, 2008-2021 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -13,7 +13,7 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
 
 
 /* Set up ACTION so that it is invoked on C stack overflow and on other,
@@ -33,12 +33,17 @@
 
    A null ACTION acts like an action that does nothing.
 
-   ACTION must be async-signal-safe.  ACTION together with its callees
-   must not require more than SIGSTKSZ bytes of stack space.  Also,
-   ACTION should not call longjmp, because this implementation does
-   not guarantee that it is safe to return to the original stack.
+   Restrictions:
+   - ACTION must be async-signal-safe.
+   - ACTION together with its callees must not require more than 64 KiB of
+     stack space.
+   - ACTION must not create and then invoke nested functions
+     <https://gcc.gnu.org/onlinedocs/gcc/Nested-Functions.html>, because
+     this implementation does not guarantee an executable stack.
+   - ACTION should not call longjmp, because this implementation does not
+     guarantee that it is safe to return to the original stack.
 
    This function may install a handler for the SIGSEGV signal or for the SIGBUS
    signal or exercise other system dependent exception handling APIs.  */
 
-extern int c_stack_action (void (* /*action*/) (int));
+extern int c_stack_action (_GL_ASYNC_SAFE void (* /*action*/) (int));