SITL fixs for alpine linux

Tools/ardupilotwaf/boards.py

@@ -360,6 +360,7 @@ def configure_env(self, cfg, env):
         ]
 
         cfg.check_librt(env)
+        cfg.check_feenableexcept()
 
         env.LINKFLAGS += ['-pthread',]
         env.AP_LIBRARIES += [

Tools/ardupilotwaf/cxx_checks.py

@@ -169,6 +169,22 @@ def check_librt(cfg, env):
 
     return ret
 
+@conf
+def check_feenableexcept(cfg):
+
+    cfg.check(
+        compiler='cxx',
+        fragment='''
+        #include <fenv.h>
+
+        int main() {
+            return feenableexcept(FE_OVERFLOW | FE_DIVBYZERO);
+        }''',
+        msg="Checking for feenableexcept",
+        define_name="HAVE_FEENABLEEXCEPT",
+        mandatory=False,
+    )
+
 @conf
 def check_package(cfg, env, libname):
     '''use pkg-config to look for an installed library that has a LIBNAME.pc file'''

libraries/AP_Common/missing/fenv.h

@@ -2,6 +2,7 @@
 
 #include_next <fenv.h>
 
+#ifndef HAVE_FEENABLEEXCEPT
 #if defined(__APPLE__) && defined(__MACH__)
 
 // Public domain polyfill for feenableexcept on OS X
@@ -45,4 +46,29 @@ inline int fedisableexcept(unsigned int excepts)
     return fesetenv(&fenv) ? -1 : old_excepts;
 }
 
+#else
+inline int feenableexcept(unsigned int excepts)
+{
+    #pragma STDC FENV_ACCESS ON
+    fexcept_t flags;
+    /* Save current exception flags. */
+    fegetexceptflag(&flags, FE_ALL_EXCEPT);
+
+    feclearexcept(FE_ALL_EXCEPT);   /* clear all fp exception conditions */
+    return fesetexceptflag(&flags, excepts) != 0 ? -1 : flags; /* set new flags */
+
+}
+
+inline int fedisableexcept(unsigned int excepts)
+{
+    #pragma STDC FENV_ACCESS ON
+    fexcept_t flags;
+    /* Save current exception flags. */
+    fegetexceptflag(&flags, FE_ALL_EXCEPT);
+
+    feclearexcept(FE_ALL_EXCEPT);   /* clear all fp exception conditions */
+    return fesetexceptflag(&flags, ~excepts) != 0 ? -1 : flags; /* set new flags */
+}
+
+#endif
 #endif

libraries/AP_HAL_SITL/UART_utils.cpp

@@ -26,6 +26,7 @@
 #ifdef USE_TERMIOS
 #include <termios.h>
 #else
+#include <asm/ioctls.h>
 #include <asm/termbits.h>
 #endif