2020-12-27

在龙芯Fedora28上编译 FlightGear 2019.1.1 时遇到 从输出所省略的额外重寻址溢出 错误，错误信息如下：

[ 98%] Linking CXX executable fgfs
CMakeFiles/fgfs.dir/__/Scripting/NasalCanvas.cxx.o：在函数‘to_nasal_helper(Context*, osg::BoundingBoxImpl<osg::Vec3f> const&)’中：
/home/loongson/下载/flightgear/flightgear-2019.1.1/src/Scripting/NasalCanvas.cxx:90:(.text+0x238):  截断重寻址至相符: R_MIPS_CALL16 针对 _Unwind_Resume@@GCC_3.0
/home/loongson/下载/flightgear/flightgear-2019.1.1/src/Scripting/NasalCanvas.cxx:84:(.text+0x28c):  截断重寻址至相符: R_MIPS_CALL16 针对 _Unwind_Resume@@GCC_3.0
CMakeFiles/fgfs.dir/__/Scripting/NasalCanvas.cxx.o：在函数‘f_createCanvas(nasal::CallContext const&)’中：
/home/loongson/下载/flightgear/flightgear-2019.1.1/src/Scripting/NasalCanvas.cxx:127:(.text+0x4e4):  截断重寻址至相符: R_MIPS_CALL16 针对 std::allocator<char>::allocator()@@GLIBCXX_3.4
/home/loongson/下载/flightgear/flightgear-2019.1.1/src/Scripting/NasalCanvas.cxx:127:(.text+0x508):  截断重寻址至相符: R_MIPS_CALL16 针对 std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(char const*, std::allocator<char> const&)
/home/loongson/下载/flightgear/flightgear-2019.1.1/src/Scripting/NasalCanvas.cxx:127:(.text+0x580):  截断重寻址至相符: R_MIPS_CALL16 针对 std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::~basic_string()
/home/loongson/下载/flightgear/flightgear-2019.1.1/src/Scripting/NasalCanvas.cxx:127:(.text+0x594):  截断重寻址至相符: R_MIPS_CALL16 针对 std::allocator<char>::~allocator()@@GLIBCXX_3.4
/home/loongson/下载/flightgear/flightgear-2019.1.1/src/Scripting/NasalCanvas.cxx:127:(.text+0x5fc):  截断重寻址至相符: R_MIPS_CALL16 针对 std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::~basic_string()
/home/loongson/下载/flightgear/flightgear-2019.1.1/src/Scripting/NasalCanvas.cxx:127:(.text+0x61c):  截断重寻址至相符: R_MIPS_CALL16 针对 std::allocator<char>::~allocator()@@GLIBCXX_3.4
/home/loongson/下载/flightgear/flightgear-2019.1.1/src/Scripting/NasalCanvas.cxx:127:(.text+0x634):  截断重寻址至相符: R_MIPS_CALL16 针对 _Unwind_Resume@@GCC_3.0
CMakeFiles/fgfs.dir/__/Scripting/NasalCanvas.cxx.o：在函数‘f_createWindow(nasal::CallContext const&)’中：
/home/loongson/下载/flightgear/flightgear-2019.1.1/src/Scripting/NasalCanvas.cxx:137:(.text+0x6d0):  截断重寻址至相符: R_MIPS_CALL16 针对 std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string()@@GLIBCXX_3.4.21
/home/loongson/下载/flightgear/flightgear-2019.1.1/src/Scripting/NasalCanvas.cxx:137:(.text+0x7a4):  从输出所省略的额外重寻址溢出
collect2: 错误：ld 返回 1
make[2]: *** [src/Main/CMakeFiles/fgfs.dir/build.make:7427：src/Main/fgfs] 错误 1
make[1]: *** [CMakeFiles/Makefile2:2133：src/Main/CMakeFiles/fgfs.dir/all] 错误 2
make: *** [Makefile:163：all] 错误 2

大佬指点后得知需要添加cxxflag -mxgot 。最终解决如下：

在 CMakeList.txt 中添加一行（我添加在了第55行）：

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -mxgot")

重新 cmake && make 通过。