compiling, crashing when run

unittests/testcfg/rtems/cmake/rtems-qemu-toolchain.cmake

@@ -0,0 +1,23 @@
+# the name of the target operating system
+set(CMAKE_SYSTEM_NAME aarch64-rtems6)
+
+set(CMAKE_SYSTEM_PROCESSOR a72)
+
+# which compilers to use for C and C++
+set(CMAKE_C_COMPILER   aarch64-rtems6-gcc)
+set(CMAKE_CXX_COMPILER aarch64-rtems6-g++)
+
+set(CMAKE_C_COMPILER_WORKS 1)
+set(CMAKE_CXX_COMPILER_WORKS 1)
+
+# where is the target environment located
+#set(CMAKE_FIND_ROOT_PATH  /usr/i586-mingw32msvc
+#    /home/alex/mingw-install)
+
+# adjust the default behavior of the FIND_XXX() commands:
+# search programs in the host environment
+set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
+
+# search headers and libraries in the target environment
+set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
+set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)

unittests/testcfg/rtems/include/cmath

@@ -0,0 +1,39 @@
+#pragma once
+
+#include_next <cmath>
+
+extern "C++"
+{
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+
+#undef lround
+#undef erfc
+#undef round
+
+
+using ::lround;
+
+long
+  lround(float __x);
+
+  constexpr long
+  lround(long double __x);
+
+using ::erfc;
+  
+constexpr float
+  erfc(float __x);
+
+  constexpr long double
+  erfc(long double __x);
+  
+  constexpr float
+  round(float __x);
+
+  using ::round;
+  
+  constexpr long double
+  round(long double __x);
+}
+}