From 5c349a1c391c9ce171a1c80f5164fae764f27dba Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andr=C3=A9=20Draszik?= <adraszik@tycoint.com>
Date: Wed, 24 Aug 2016 20:58:59 +0100
Subject: [PATCH 2/4] boost/test/execution_monitor.hpp: fix mips soft float
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gcc.compile.c++ <builddir>/boost/bin.v2/libs/test/build/gcc-4.3.1/release/threading-multi/execution_monitor.o

    "mipsel-poky-linux-musl-g++" "-mel" "-mabi=32" "-msoft-float" "-march=mips32r2" "-mips16" "-minterlink-compressed" "-mtune=24kec" "-mdsp" "-Wl,-O1" "-Wl,--as-needed" "-fstack-protector-strong" "-Wl,-z,relro,-z,now" "--sysroot=<sysroot>"  -ftemplate-depth-128 -O2 -pipe -g -feliminate-unused-debug-types -fdebug-prefix-map=<srcdir>=/usr/src/debug/boost/1.61.0-r0 -fdebug-prefix-map=<sysroot_host>= -fdebug-prefix-map=<sysroot>= -fstack-protector-strong -pie -fpie -D_FORTIFY_SOURCE=2 -Wformat -Wformat-security -Werror=format-security -fvisibility-inlines-hidden -O3 -finline-functions -Wno-inline -Wall -pedantic -pthread -fPIC -Wno-variadic-macros -DBOOST_ALL_NO_LIB=1 -DBOOST_CHRONO_DYN_LINK=1 -DBOOST_SYSTEM_DYN_LINK=1 -DBOOST_SYSTEM_NO_DEPRECATED -DBOOST_TEST_DYN_LINK=1 -DBOOST_TIMER_DYN_LINK=1 -DNDEBUG  -I"." -c -o "<builddir>/boost/bin.v2/libs/test/build/gcc-4.3.1/release/threading-multi/execution_monitor.o" "libs/test/src/execution_monitor.cpp"

In file included from ./boost/test/impl/execution_monitor.ipp:31:0,
                 from libs/test/src/execution_monitor.cpp:16:
./boost/test/execution_monitor.hpp:491:27: error: 'FE_DIVBYZERO' was not declared in this scope
     BOOST_FPE_DIVBYZERO = FE_DIVBYZERO,
                           ^~~~~~~~~~~~
./boost/test/execution_monitor.hpp:492:27: error: 'FE_INEXACT' was not declared in this scope
     BOOST_FPE_INEXACT   = FE_INEXACT,
                           ^~~~~~~~~~
./boost/test/execution_monitor.hpp:493:27: error: 'FE_INVALID' was not declared in this scope
     BOOST_FPE_INVALID   = FE_INVALID,
                           ^~~~~~~~~~
./boost/test/execution_monitor.hpp:494:27: error: 'FE_OVERFLOW' was not declared in this scope
     BOOST_FPE_OVERFLOW  = FE_OVERFLOW,
                           ^~~~~~~~~~~
./boost/test/execution_monitor.hpp:495:27: error: 'FE_UNDERFLOW' was not declared in this scope
     BOOST_FPE_UNDERFLOW = FE_UNDERFLOW,
                           ^~~~~~~~~~~~

The reason is that some (notably FPU-less) architectures,
including mips*-nf, don't define/implement some of the
floating point constants, even though fenv.h is
available.

The key point is:
  A fully standards conforming fenv.h does not have to
  define any FE_* macros, and if it does define them,
  then it defines macros only for the FP exceptions it
  actually supports.

So correct usage requires a triple check:
1) Check BOOST_NO_FENV_H to see if the header is supported.
2) Include the header and then check FE_ALL_EXCEPT to see
   if any FP exceptions are supported.
3) Before using the individual FE_* macros, you need to
   check for their existence too as not all may be
   supported.

https://svn.boost.org/trac/boost/ticket/11756

Other projects have similar issues, e.g. pixman, and
apply similar work-arounds:
  https://lists.freedesktop.org/archives/pixman/2014-February/003172.html

Architectures are notably also allowed to define FE_ALL_EXCEPT to 0!
Keeping this in mind, and knowing that the compiler will eliminate
code that can't be executed, we can change BOOST_FPE_ALL to be 0 for
the case of compiling using Clang and/or fenv.h being unavailable
as well, which allows simplification of the #ifdef's in
execution_monitor.ipp a bit.

Signed-off-by: André Draszik <adraszik@tycoint.com>
---
Upstream-Status: Submitted https://svn.boost.org/trac/boost/ticket/11756
 boost/test/execution_monitor.hpp      | 26 +++++++++++++++++++++++++-
 boost/test/impl/execution_monitor.ipp | 10 ++++++++--
 2 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/boost/test/execution_monitor.hpp b/boost/test/execution_monitor.hpp
index 0eee497..44fe59d 100644
--- a/boost/test/execution_monitor.hpp
+++ b/boost/test/execution_monitor.hpp
@@ -486,15 +486,39 @@ enum masks {
     BOOST_FPE_ALL       = MCW_EM,
 #elif defined(BOOST_NO_FENV_H) || defined(BOOST_CLANG) \
     || defined(__ARM_PCS)
-    BOOST_FPE_ALL       = 1,
+    BOOST_FPE_ALL       = 0,
 #else
+#if defined(FE_DIVBYZERO)
     BOOST_FPE_DIVBYZERO = FE_DIVBYZERO,
+#else
+    BOOST_FPE_DIVBYZERO = 0,
+#endif
+#if defined(FE_INEXACT)
     BOOST_FPE_INEXACT   = FE_INEXACT,
+#else
+    BOOST_FPE_INEXACT   = 0,
+#endif
+#if defined(FE_INVALID)
     BOOST_FPE_INVALID   = FE_INVALID,
+#else
+    BOOST_FPE_INVALID   = 0,
+#endif
+#if defined(FE_OVERFLOW)
     BOOST_FPE_OVERFLOW  = FE_OVERFLOW,
+#else
+    BOOST_FPE_OVERFLOW  = 0,
+#endif
+#if defined(FE_UNDERFLOW)
     BOOST_FPE_UNDERFLOW = FE_UNDERFLOW,
+#else
+    BOOST_FPE_UNDERFLOW = 0,
+#endif
 
+#if defined(FE_ALL_EXCEPT)
     BOOST_FPE_ALL       = FE_ALL_EXCEPT,
+#else
+    BOOST_FPE_ALL       = 0,
+#endif
 #endif
     BOOST_FPE_INV       = BOOST_FPE_ALL+1
 };
diff --git a/boost/test/impl/execution_monitor.ipp b/boost/test/impl/execution_monitor.ipp
index f7fc8ea..d1088b9 100644
--- a/boost/test/impl/execution_monitor.ipp
+++ b/boost/test/impl/execution_monitor.ipp
@@ -1381,7 +1381,10 @@ enable( unsigned mask )
 #endif
 
     return ~old_cw & BOOST_FPE_ALL;
-#elif defined(__GLIBC__) && defined(__USE_GNU) && !defined(BOOST_CLANG) && !defined(BOOST_NO_FENV_H)
+#elif defined(__GLIBC__) && defined(__USE_GNU)
+    if (BOOST_FPE_ALL == 0)
+        /* Not Implemented */
+        return 0;
     feclearexcept(BOOST_FPE_ALL);
     int res = feenableexcept( mask );
     return res == -1 ? (unsigned)BOOST_FPE_INV : (unsigned)res;
@@ -1418,7 +1421,10 @@ disable( unsigned mask )
 #endif
 
     return ~old_cw & BOOST_FPE_ALL;
-#elif defined(__GLIBC__) && defined(__USE_GNU) && !defined(BOOST_CLANG) && !defined(BOOST_NO_FENV_H)
+#elif defined(__GLIBC__) && defined(__USE_GNU)
+    if (BOOST_FPE_ALL == 0)
+        /* Not Implemented */
+        return BOOST_FPE_INV;
     feclearexcept(BOOST_FPE_ALL);
     int res = fedisableexcept( mask );
     return res == -1 ? (unsigned)BOOST_FPE_INV : (unsigned)res;
-- 
2.9.3

