Mercurial > gnulib
view doc/alloca.texi @ 40156:066c585853e5
tests: Accommodate a shell that is not in /bin/sh.
* tests/init.sh (setup_): Set srcdir and builddir.
(BOURNE_SHELL): New variable.
* modules/acl-tests (Depends-on): Add 'test-framework-sh'.
* modules/file-has-acl-tests (Depends-on): Likewise.
* modules/copy-file-tests (Depends-on): Likewise.
* tests/test-set-mode-acl-1.sh: Use the test framework. Invoke shell
scripts through $BOURNE_SHELL.
* tests/test-set-mode-acl-2.sh: Likewise.
* tests/test-copy-acl-1.sh: Likewise.
* tests/test-copy-acl-2.sh: Likewise.
* tests/test-file-has-acl-1.sh: Likewise.
* tests/test-file-has-acl-2.sh: Likewise.
* tests/test-copy-file-1.sh: Likewise.
* tests/test-copy-file-2.sh: Likewise.
* tests/test-set-mode-acl.sh (builddir): Consider value set by the
invoker.
* tests/test-copy-acl.sh (builddir): Likewise.
* tests/test-file-has-acl.sh (builddir): Likewise.
* tests/test-copy-file.sh (builddir): Likewise.
* tests/test-vc-list-files-cvs.sh: Don't create shims for executables in
build-aux/. Instead, invoke shell scripts through $BOURNE_SHELL.
* tests/test-vc-list-files-git.sh: Likewise.
author | Bruno Haible <bruno@clisp.org> |
---|---|
date | Sun, 27 Jan 2019 16:01:23 +0100 |
parents | b06060465f09 |
children |
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@c Documentation of gnulib module 'alloca'. @c Copyright (C) 2004, 2007, 2009-2019 Free Software Foundation, Inc. @c Permission is granted to copy, distribute and/or modify this document @c under the terms of the GNU Free Documentation License, Version 1.3 or @c any later version published by the Free Software Foundation; with no @c Invariant Sections, no Front-Cover Texts, and no Back-Cover @c Texts. A copy of the license is included in the ``GNU Free @c Documentation License'' file as part of this distribution. The @code{alloca} module provides for a function @code{alloca} which allocates memory on the stack, where the system allows it. A memory block allocated with @code{alloca} exists only until the function that calls @code{alloca} returns or exits abruptly. There are a few systems where this is not possible: HP-UX systems, and some other platforms when the C++ compiler is used. On these platforms the alloca module provides a @code{malloc} based emulation. This emulation will not free a memory block immediately when the calling function returns, but rather will wait until the next @code{alloca} call from a function with the same or a shorter stack length. Thus, in some cases, a few memory blocks will be kept although they are not needed any more. The user can @code{#include <alloca.h>} and use @code{alloca} on all platforms. Note that the @code{#include <alloca.h>} must be the first one after the autoconf-generated @file{config.h}, for AIX 3 compatibility. Thanks to IBM for this nice restriction! Note that GCC 3.1 and 3.2 can @emph{inline} functions that call @code{alloca}. When this happens, the memory blocks allocated with @code{alloca} will not be freed until @emph{the end of the calling function}. If this calling function runs a loop calling the function that uses @code{alloca}, the program easily gets a stack overflow and crashes. To protect against this compiler behaviour, you can mark the function that uses @code{alloca} with the following attribute: @smallexample #ifdef __GNUC__ __attribute__ ((__noinline__)) #endif @end smallexample An alternative to this module is the @samp{alloca-opt} module.