From 695965c27be74acb5968f19d51af86065c4b71a9 Mon Sep 17 00:00:00 2001
From: Hongxu Jia <hongxu.jia@windriver.com>
Date: Mon, 13 May 2019 09:48:14 +0800
Subject: [PATCH] support musl

...
|./lib/math.h:2877:1: error: 'int signbit(float)' conflicts with a previous declaration
| _GL_MATH_CXX_REAL_FLOATING_DECL_2 (signbit)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|In file included from recipe-sysroot/usr/include/c++/8.3.0/math.h:36,
|                 from ./lib/math.h:27,
|                 from ./src/include/driver.h:27,
|                 from src/devices/grodvi/dvi.cpp:20:
|recipe-sysroot/usr/include/c++/8.3.0/cmath:661:3: note: previous declaration 'constexpr bool std::signbit(float)'
|   signbit(float __x)
|   ^~~~~~~
...

Upstream-Status: Backport [http://git.savannah.gnu.org/gitweb/?p=gnulib.git;a=commit;h=453ff940449bbbde9ec00f0bbf82a359c5598fc7]

Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com>
---
 gnulib_m4/signbit.m4 | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/gnulib_m4/signbit.m4 b/gnulib_m4/signbit.m4
index 9e7884d..8b9c70c 100644
--- a/gnulib_m4/signbit.m4
+++ b/gnulib_m4/signbit.m4
@@ -31,6 +31,8 @@ AC_DEFUN([gl_SIGNBIT],
         [case "$host_os" in
                           # Guess yes on glibc systems.
            *-gnu* | gnu*) gl_cv_func_signbit="guessing yes" ;;
+                          # Guess yes on musl systems.
+           *-musl*)       gl_cv_func_signbit="guessing yes" ;;
                           # Guess yes on native Windows.
            mingw*)        gl_cv_func_signbit="guessing yes" ;;
                           # If we don't know, assume the worst.
-- 
2.7.4