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| | From c2921b17a37e887b8a5ca9d84b875b9ba702b79c Mon Sep 17 00:00:00 2001
From: "Gabriel F. T. Gomes" <gftg@linux.vnet.ibm.com>
Date: Mon, 21 Aug 2017 14:23:27 +0200
Subject: [PATCH 10/90] Do not use __builtin_types_compatible_p in C++ mode
(bug 21930)
The logic to define isinf for float128 depends on the availability of
__builtin_types_compatible_p, which is only available in C mode,
however, the conditionals do not check for C or C++ mode. This lead to
an error in libstdc++ configure, as reported by bug 21930.
This patch adds a conditional for C mode in the definition of isinf for
float128. No definition is provided in C++ mode, since libstdc++
headers undefine isinf.
Tested for powerpc64le (glibc test suite and libstdc++-v3 configure).
[BZ #21930]
* math/math.h (isinf): Check if in C or C++ mode before using
__builtin_types_compatible_p, since this is a C mode feature.
(cherry picked from commit 47a67213a9f51c5f8816d240500b10db605d8b77)
diff --git a/ChangeLog b/ChangeLog
index 6886cd9361..415fa3cc79 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2017-08-18 Gabriel F. T. Gomes <gftg@linux.vnet.ibm.com>
+
+ [BZ #21930]
+ * math/math.h (isinf): Check if in C or C++ mode before using
+ __builtin_types_compatible_p, since this is a C mode feature.
+
2017-08-10 Gabriel F. T. Gomes <gftg@linux.vnet.ibm.com>
[BZ #21941]
diff --git a/NEWS b/NEWS
index d57c4052cf..75b82c899e 100644
--- a/NEWS
+++ b/NEWS
@@ -11,6 +11,7 @@ The following bugs are resolved with this release:
[21242] assert: Suppress pedantic warning caused by statement expression
[21885] getaddrinfo: Release resolver context on error in gethosts
+ [21930] Do not use __builtin_types_compatible_p in C++ mode
[21932] Unpaired __resolv_context_get in generic get*_r implementation
\f
Version 2.26
diff --git a/math/math.h b/math/math.h
index e21708045a..dea8dbe1ae 100644
--- a/math/math.h
+++ b/math/math.h
@@ -442,8 +442,12 @@ enum
/* Return nonzero value if X is positive or negative infinity. */
# if __HAVE_DISTINCT_FLOAT128 && !__GNUC_PREREQ (7,0) \
- && !defined __SUPPORT_SNAN__
- /* __builtin_isinf_sign is broken for float128 only before GCC 7.0. */
+ && !defined __SUPPORT_SNAN__ && !defined __cplusplus
+ /* Since __builtin_isinf_sign is broken for float128 before GCC 7.0,
+ use the helper function, __isinff128, with older compilers. This is
+ only provided for C mode, because in C++ mode, GCC has no support
+ for __builtin_types_compatible_p (and when in C++ mode, this macro is
+ not used anyway, because libstdc++ headers undefine it). */
# define isinf(x) \
(__builtin_types_compatible_p (__typeof (x), _Float128) \
? __isinff128 (x) : __builtin_isinf_sign (x))
|