Prepare for radical source tree reorganization. zack/build-layout-experiment

All top-level files and directories are moved into a temporary storage
directory, REORG.TODO, except for files that will certainly still
exist in their current form at top level when we're done (COPYING,
COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which
are moved to the new directory OldChangeLogs, instead), and the
generated file INSTALL (which is just deleted; in the new order, there
will be no generated files checked into version control).

1 files changed, 73 insertions, 0 deletions

diff --git a/REORG.TODO/math/lgamma-compat.h b/REORG.TODO/math/lgamma-compat.h
new file mode 100644
index 0000000000..90a423756a
--- /dev/null
+++ b/REORG.TODO/math/lgamma-compat.h
@@ -0,0 +1,73 @@
+/* ABI compatibility for lgamma functions.
+   Copyright (C) 2015-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef LGAMMA_COMPAT_H
+#define LGAMMA_COMPAT_H 1
+
+#include <shlib-compat.h>
+
+/* XSI POSIX requires lgamma to set signgam, but ISO C does not permit
+   this.  Namespace issues can be avoided if the functions set
+   __signgam and signgam is a weak alias, but this only works if both
+   signgam and __signgam were exported from the glibc version the
+   program was linked against.  Before glibc 2.23, lgamma functions
+   set signgam which was not a weak alias for __signgam, so old
+   binaries have dynamic symbols for signgam only and the versions of
+   lgamma used for old binaries must set both signgam and __signgam.
+   Those versions also do a check of _LIB_VERSION != _ISOC_ to match
+   old glibc.
+
+   Users of this file define USE_AS_COMPAT to 0 when building the main
+   version of lgamma, 1 when building the compatibility version.  */
+
+#define LGAMMA_OLD_VER GLIBC_2_0
+#define LGAMMA_NEW_VER GLIBC_2_23
+#define HAVE_LGAMMA_COMPAT SHLIB_COMPAT (libm, LGAMMA_OLD_VER, LGAMMA_NEW_VER)
+
+/* Whether to build this version at all.  */
+#define BUILD_LGAMMA (HAVE_LGAMMA_COMPAT || !USE_AS_COMPAT)
+
+/* The name to use for this version.  */
+#if USE_AS_COMPAT
+# define LGFUNC(FUNC) FUNC ## _compat
+#else
+# define LGFUNC(FUNC) FUNC
+#endif
+
+/* If there is a compatibility version, gamma (not an ISO C function,
+   so never a problem for it to set signgam) points directly to it
+   rather than having separate versions.  */
+#define GAMMA_ALIAS (USE_AS_COMPAT ? HAVE_LGAMMA_COMPAT : !HAVE_LGAMMA_COMPAT)
+
+/* How to call the underlying lgamma_r function.  */
+#define CALL_LGAMMA(TYPE, FUNC, ARG)			\
+  ({							\
+    TYPE lgamma_tmp;					\
+    int local_signgam;					\
+    if (USE_AS_COMPAT)					\
+      {							\
+	lgamma_tmp = FUNC ((ARG), &local_signgam);	\
+	if (_LIB_VERSION != _ISOC_)			\
+	  signgam = __signgam = local_signgam;		\
+      }							\
+    else						\
+      lgamma_tmp = FUNC ((ARG), &__signgam);		\
+    lgamma_tmp;						\
+  })
+
+#endif /* lgamma-compat.h.  */