Move LDBL_CLASSIFY_COMPAT to its own header.

The general rule in glibc is that it's better for a macro to be always
defined, and tested with #if, than for it to be tested with #ifdef,
because the latter is prone to typos in the macro name as well as to
the header with the macro accidentally not being included in a file
testing it.  (Testing with an "if" statement is even better, in those
cases where it's possible to do things that way, as it then means both
cases in the code get checked for syntax in glibc builds with either
value of the condition.)

math_private.h has several different groups of macros, meaning that
architectures wanting to override some of them need to define those
then include the generic version, which then defines macros if not
already defined.  It's hard to avoid that arrangement completely, but
various cases can be improved by splitting out macros or groups of
macros into separate files.

This patch splits out the LDBL_CLASSIFY_COMPAT macro into a separate
ldbl-classify-compat.h header.  This macro is tested with #ifdef; this
patch changes it to testing with #if, with a default definition to 0
in the generic header and then architecture-specific headers defining
it to 1.

Tested with build-many-glibcs.py that installed stripped shared
libraries are unchanged by the patch.

	* sysdeps/generic/ldbl-classify-compat.h: New file.
	* sysdeps/arm/ldbl-classify-compat.h: Likewise.
	* sysdeps/m68k/coldfire/ldbl-classify-compat.h: Likewise.
	* sysdeps/microblaze/ldbl-classify-compat.h: Likewise.
	* sysdeps/mips/ldbl-classify-compat.h: Likewise.
	* sysdeps/nios2/ldbl-classify-compat.h: Likewise.
	* sysdeps/sh/ldbl-classify-compat.h: Likewise.
	* sysdeps/ieee754/dbl-64/s_finite.c: Include
	<ldbl-classify-compat.h>.
	[LDBL_CLASSIFY_COMPAT]: Test value, not whether defined.
	* sysdeps/ieee754/dbl-64/s_isinf.c: Include
	<ldbl-classify-compat.h>.
	[LDBL_CLASSIFY_COMPAT]: Test value, not whether defined.
	* sysdeps/ieee754/dbl-64/s_isnan.c: Include
	<ldbl-classify-compat.h>.
	[LDBL_CLASSIFY_COMPAT]: Test value, not whether defined.
	* sysdeps/ieee754/dbl-64/wordsize-64/s_finite.c: Include
	<ldbl-classify-compat.h>.
	[LDBL_CLASSIFY_COMPAT]: Test value, not whether defined.
	* sysdeps/ieee754/dbl-64/wordsize-64/s_isinf.c: Include
	<ldbl-classify-compat.h>.
	[LDBL_CLASSIFY_COMPAT]: Test value, not whether defined.
	* sysdeps/ieee754/dbl-64/wordsize-64/s_isnan.c: Include
	<ldbl-classify-compat.h>.
	[LDBL_CLASSIFY_COMPAT]: Test value, not whether defined.
	* sysdeps/arm/math_private.h (LDBL_CLASSIFY_COMPAT): Remove macro.
	* sysdeps/mips/math_private.h (LDBL_CLASSIFY_COMPAT): Likewise.
	* sysdeps/m68k/coldfire/math_private.h: Remove file.
	* sysdeps/microblaze/math_private.h: Likewise.
	* sysdeps/nios2/math_private.h: Likewise.
	* sysdeps/sh/math_private.h: Likewise.

15 files changed, 69 insertions, 30 deletions

diff --git a/sysdeps/sh/math_private.h b/sysdeps/arm/ldbl-classify-compat.h
index d13f2d49d3..f3f10607ca 100644
--- a/sysdeps/sh/math_private.h
+++ b/sysdeps/arm/ldbl-classify-compat.h
@@ -1,10 +1,8 @@
-#ifndef SH_MATH_PRIVATE_H
-#define SH_MATH_PRIVATE_H 1
+#ifndef ARM_LDBL_CLASSIFY_COMPAT_H
+#define ARM_LDBL_CLASSIFY_COMPAT_H 1
 
 /* Enable __finitel, __isinfl, and __isnanl for binary compatibility
    when built without long double support. */
 #define LDBL_CLASSIFY_COMPAT 1
 
-#include_next <math_private.h>
-
 #endif
diff --git a/sysdeps/arm/math_private.h b/sysdeps/arm/math_private.h
index d39e9ee24a..c175b15601 100644
--- a/sysdeps/arm/math_private.h
+++ b/sysdeps/arm/math_private.h
@@ -1,10 +1,6 @@
 #ifndef ARM_MATH_PRIVATE_H
 #define ARM_MATH_PRIVATE_H 1
 
-/* Enable __finitel, __isinfl, and __isnanl for binary compatibility
-   when built without long double support. */
-#define LDBL_CLASSIFY_COMPAT 1
-
 #include "fenv_private.h"
 #include_next <math_private.h>
 
diff --git a/sysdeps/generic/ldbl-classify-compat.h b/sysdeps/generic/ldbl-classify-compat.h
new file mode 100644
index 0000000000..d77ca18275
--- /dev/null
+++ b/sysdeps/generic/ldbl-classify-compat.h
@@ -0,0 +1,33 @@
+/* Specify whether there should be compat symbol aliases for some
+   classification functions.  Generic version.
+   Copyright (C) 2015-2018 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 _LDBL_CLASSIFY_COMPAT_H
+#define _LDBL_CLASSIFY_COMPAT_H	1
+
+/* If defined to 1, enable __finitel, __isinfl, and __isnanl function
+   aliases for binary compatibility when built without long double
+   support.  If defined to 0, or if long double does not have the same
+   format as double, there are no such aliases.  New ports should use
+   the default definition of this as 0, as such
+   implementation-namespace functions should only have one exported
+   name per floating-point format, not one per floating-point
+   type.  */
+#define LDBL_CLASSIFY_COMPAT 0
+
+#endif /* ldbl-classify-compat.h */
diff --git a/sysdeps/ieee754/dbl-64/s_finite.c b/sysdeps/ieee754/dbl-64/s_finite.c
index eed80c6449..da1519b1d0 100644
--- a/sysdeps/ieee754/dbl-64/s_finite.c
+++ b/sysdeps/ieee754/dbl-64/s_finite.c
@@ -21,6 +21,7 @@ static char rcsid[] = "$NetBSD: s_finite.c,v 1.8 1995/05/10 20:47:17 jtc Exp $";
 
 #include <math.h>
 #include <math_private.h>
+#include <ldbl-classify-compat.h>
 #include <shlib-compat.h>
 
 #undef __finite
@@ -38,7 +39,7 @@ int FINITE(double x)
 hidden_def (__finite)
 weak_alias (__finite, finite)
 #ifdef NO_LONG_DOUBLE
-# ifdef LDBL_CLASSIFY_COMPAT
+# if LDBL_CLASSIFY_COMPAT
 #  if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_23)
 compat_symbol (libc, __finite, __finitel, GLIBC_2_0);
 #  endif
diff --git a/sysdeps/ieee754/dbl-64/s_isinf.c b/sysdeps/ieee754/dbl-64/s_isinf.c
index c0ad54538a..93eb65c147 100644
--- a/sysdeps/ieee754/dbl-64/s_isinf.c
+++ b/sysdeps/ieee754/dbl-64/s_isinf.c
@@ -15,6 +15,7 @@ static char rcsid[] = "$NetBSD: s_isinf.c,v 1.3 1995/05/11 23:20:14 jtc Exp $";
 
 #include <math.h>
 #include <math_private.h>
+#include <ldbl-classify-compat.h>
 #include <shlib-compat.h>
 
 int
@@ -29,7 +30,7 @@ __isinf (double x)
 hidden_def (__isinf)
 weak_alias (__isinf, isinf)
 #ifdef NO_LONG_DOUBLE
-# if defined LDBL_CLASSIFY_COMPAT && SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_23)
+# if LDBL_CLASSIFY_COMPAT && SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_23)
 compat_symbol (libc, __isinf, __isinfl, GLIBC_2_0);
 # endif
 weak_alias (__isinf, isinfl)
diff --git a/sysdeps/ieee754/dbl-64/s_isnan.c b/sysdeps/ieee754/dbl-64/s_isnan.c
index 642ec3a494..82723eeb8a 100644
--- a/sysdeps/ieee754/dbl-64/s_isnan.c
+++ b/sysdeps/ieee754/dbl-64/s_isnan.c
@@ -21,6 +21,7 @@ static char rcsid[] = "$NetBSD: s_isnan.c,v 1.8 1995/05/10 20:47:36 jtc Exp $";
 
 #include <math.h>
 #include <math_private.h>
+#include <ldbl-classify-compat.h>
 #include <shlib-compat.h>
 
 #undef __isnan
@@ -37,7 +38,7 @@ __isnan (double x)
 hidden_def (__isnan)
 weak_alias (__isnan, isnan)
 #ifdef NO_LONG_DOUBLE
-# if defined LDBL_CLASSIFY_COMPAT && SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_23)
+# if LDBL_CLASSIFY_COMPAT && SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_23)
 compat_symbol (libc, __isnan, __isnanl, GLIBC_2_0);
 # endif
 weak_alias (__isnan, isnanl)
diff --git a/sysdeps/ieee754/dbl-64/wordsize-64/s_finite.c b/sysdeps/ieee754/dbl-64/wordsize-64/s_finite.c
index ef51608f6e..40676924fe 100644
--- a/sysdeps/ieee754/dbl-64/wordsize-64/s_finite.c
+++ b/sysdeps/ieee754/dbl-64/wordsize-64/s_finite.c
@@ -16,6 +16,7 @@
 
 #include <math.h>
 #include <math_private.h>
+#include <ldbl-classify-compat.h>
 #include <shlib-compat.h>
 #include <stdint.h>
 
@@ -30,7 +31,7 @@ __finite(double x)
 hidden_def (__finite)
 weak_alias (__finite, finite)
 #ifdef NO_LONG_DOUBLE
-# ifdef LDBL_CLASSIFY_COMPAT
+# if LDBL_CLASSIFY_COMPAT
 #  if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_23)
 compat_symbol (libc, __finite, __finitel, GLIBC_2_0);
 #  endif
diff --git a/sysdeps/ieee754/dbl-64/wordsize-64/s_isinf.c b/sysdeps/ieee754/dbl-64/wordsize-64/s_isinf.c
index 951fb73239..2b427a8b4c 100644
--- a/sysdeps/ieee754/dbl-64/wordsize-64/s_isinf.c
+++ b/sysdeps/ieee754/dbl-64/wordsize-64/s_isinf.c
@@ -11,6 +11,7 @@
 
 #include <math.h>
 #include <math_private.h>
+#include <ldbl-classify-compat.h>
 #include <shlib-compat.h>
 
 int
@@ -26,7 +27,7 @@ __isinf (double x)
 hidden_def (__isinf)
 weak_alias (__isinf, isinf)
 #ifdef NO_LONG_DOUBLE
-# if defined LDBL_CLASSIFY_COMPAT && SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_23)
+# if LDBL_CLASSIFY_COMPAT && SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_23)
 compat_symbol (libc, __isinf, __isinfl, GLIBC_2_0);
 # endif
 weak_alias (__isinf, isinfl)
diff --git a/sysdeps/ieee754/dbl-64/wordsize-64/s_isnan.c b/sysdeps/ieee754/dbl-64/wordsize-64/s_isnan.c
index bcff9e3b67..cd805d157b 100644
--- a/sysdeps/ieee754/dbl-64/wordsize-64/s_isnan.c
+++ b/sysdeps/ieee754/dbl-64/wordsize-64/s_isnan.c
@@ -17,6 +17,7 @@
 
 #include <math.h>
 #include <math_private.h>
+#include <ldbl-classify-compat.h>
 #include <shlib-compat.h>
 #include <stdint.h>
 
@@ -32,7 +33,7 @@ int __isnan(double x)
 hidden_def (__isnan)
 weak_alias (__isnan, isnan)
 #ifdef NO_LONG_DOUBLE
-# if defined LDBL_CLASSIFY_COMPAT && SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_23)
+# if LDBL_CLASSIFY_COMPAT && SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_23)
 compat_symbol (libc, __isnan, __isnanl, GLIBC_2_0);
 # endif
 weak_alias (__isnan, isnanl)
diff --git a/sysdeps/nios2/math_private.h b/sysdeps/m68k/coldfire/ldbl-classify-compat.h
index bc7f9c8e90..c1ec4d4ffa 100644
--- a/sysdeps/nios2/math_private.h
+++ b/sysdeps/m68k/coldfire/ldbl-classify-compat.h
@@ -1,10 +1,8 @@
-#ifndef NIO2_MATH_PRIVATE_H
-#define NIO2_MATH_PRIVATE_H 1
+#ifndef COLDFIRE_LDBL_CLASSIFY_COMPAT_H
+#define COLDFIRE_LDBL_CLASSIFY_COMPAT_H 1
 
 /* Enable __finitel, __isinfl, and __isnanl for binary compatibility
    when built without long double support. */
 #define LDBL_CLASSIFY_COMPAT 1
 
-#include_next <math_private.h>
-
 #endif
diff --git a/sysdeps/m68k/coldfire/math_private.h b/sysdeps/microblaze/ldbl-classify-compat.h
index d306a508b4..38c5c99949 100644
--- a/sysdeps/m68k/coldfire/math_private.h
+++ b/sysdeps/microblaze/ldbl-classify-compat.h
@@ -1,10 +1,8 @@
-#ifndef COLDFIRE_MATH_PRIVATE_H
-#define COLDFIRE_MATH_PRIVATE_H 1
+#ifndef MICROBLAZE_LDBL_CLASSIFY_COMPAT_H
+#define MICROBLAZE_LDBL_CLASSIFY_COMPAT_H 1
 
 /* Enable __finitel, __isinfl, and __isnanl for binary compatibility
    when built without long double support. */
 #define LDBL_CLASSIFY_COMPAT 1
 
-#include_next <math_private.h>
-
 #endif
diff --git a/sysdeps/microblaze/math_private.h b/sysdeps/mips/ldbl-classify-compat.h
index 64dc18133f..547ac7b53a 100644
--- a/sysdeps/microblaze/math_private.h
+++ b/sysdeps/mips/ldbl-classify-compat.h
@@ -1,10 +1,8 @@
-#ifndef MICROBLAZE_MATH_PRIVATE_H
-#define MICROBLAZE_MATH_PRIVATE_H 1
+#ifndef MIPS_LDBL_CLASSIFY_COMPAT_H
+#define MIPS_LDBL_CLASSIFY_COMPAT_H 1
 
 /* Enable __finitel, __isinfl, and __isnanl for binary compatibility
    when built without long double support. */
 #define LDBL_CLASSIFY_COMPAT 1
 
-#include_next <math_private.h>
-
 #endif
diff --git a/sysdeps/mips/math_private.h b/sysdeps/mips/math_private.h
index a3c25138c7..01ae8b18fd 100644
--- a/sysdeps/mips/math_private.h
+++ b/sysdeps/mips/math_private.h
@@ -240,10 +240,6 @@ libc_feholdsetround_mips_ctx (struct rm_ctx *ctx, int round)
 
 #endif
 
-/* Enable __finitel, __isinfl, and __isnanl for binary compatibility
-   when built without long double support. */
-#define LDBL_CLASSIFY_COMPAT 1
-
 #include_next <math_private.h>
 
 #endif
diff --git a/sysdeps/nios2/ldbl-classify-compat.h b/sysdeps/nios2/ldbl-classify-compat.h
new file mode 100644
index 0000000000..a9614de9df
--- /dev/null
+++ b/sysdeps/nios2/ldbl-classify-compat.h
@@ -0,0 +1,8 @@
+#ifndef NIOS2_LDBL_CLASSIFY_COMPAT_H
+#define NIOS2_LDBL_CLASSIFY_COMPAT_H 1
+
+/* Enable __finitel, __isinfl, and __isnanl for binary compatibility
+   when built without long double support. */
+#define LDBL_CLASSIFY_COMPAT 1
+
+#endif
diff --git a/sysdeps/sh/ldbl-classify-compat.h b/sysdeps/sh/ldbl-classify-compat.h
new file mode 100644
index 0000000000..d3b978cdff
--- /dev/null
+++ b/sysdeps/sh/ldbl-classify-compat.h
@@ -0,0 +1,8 @@
+#ifndef SH_LDBL_CLASSIFY_COMPAT_H
+#define SH_LDBL_CLASSIFY_COMPAT_H 1
+
+/* Enable __finitel, __isinfl, and __isnanl for binary compatibility
+   when built without long double support. */
+#define LDBL_CLASSIFY_COMPAT 1
+
+#endif