'u32 fswab32(__u32)' 不能出现在 netinet/tcp_md5.h 的常量表达式中

Question

在我的一个代码中，我遇到了以下错误，因为我正在使用。

==========错误========

/auto/andpkg/rep_cache//wr-x86-xeon/5.0/sysroot/intel_xeon_32_core-wrs-linux/usr/include/linux/tcp.h:72:17: error: '__u32 __fswab32(__u32)' cannot appear in a constant-expression

=========================

于是我改为netinet/tcp.h，错误解决。然而，下一个头文件是 netinet/tcp_md5.h，我发现 netinet/tcp_md5.h 依次包含。所以现在我遇到了相同的编译错误和一些重新声明错误。

=========重新声明错误===============

在 ../../../../zeromq/conf.x86it/../zeromq-4.0.1/../../../../routing 包含的文件中-sw/include/pre-os/netinet/tcp_md5.h:59:0, 来自 ../../../../zeromq/conf.x86it/../zeromq-4.0.1/src/options.hpp:38，来自 ../../../../zeromq/conf.x86it/../zeromq-4.0.1/src/ctx.cpp:30: ../../../.. /zeromq/conf.x86it/../zeromq-4.0.1/../../../../routing-sw/include/pre-os/x86it/os /linux/tcp.h:91:0: 错误："TCP_NODELAY" 重新定义 [-Werror] ../../../../zeromq/conf.x86it/../zeromq-4.0 .1/../../../../routing-sw/include/pre-os/netinet/tcp.h:148:0: 注意：这是前面的位置定义../../../../zeromq/conf.x86it/../zeromq-4.0.1/../../../../routing-sw/include/pre-os/x86it/os/linux/tcp.h:92:0: 错误："TCP_MAXSEG" 重新定义 [-Werror] ../../../../zeromq/conf.x86it/../zeromq-4.0.1/../../../../routing-sw/include/pre-os/netinet/tcp.h:149 :0: 注意：这是前面定义的位置../../../../zeromq/conf.x86it/../zeromq-4.0.1/../../../ ../routing-sw/include/pre-os/x86it/os/linux/tcp.h:94:0: 错误："TCP_KEEPIDLE" 重新定义 [-Werror] 。 ./../../../zeromq/conf.x86it/../zeromq-4.0.1/../../../../routing-sw/include/pre-os/netinet/tcp.h:158:0: 注意：这里是之前定义的位置../../../../zeromq/conf.x86it/../zeromq-4.0 .1/../../../../ routing-sw/include/pre-os/x86it/os/linux/tcp.h:95:0: 错误："TCP_KEEPINTVL" 重新定义 [-Werror] ../. ./../../zeromq/conf.x86it/../zeromq-4.0.1/../../../../routing-sw/include/pre-os/ netinet/tcp.h:159:0: 注意：这里是之前定义的位置../../../../zeromq/conf.x86it/../zeromq-4.0.1/ ../../../../routing-sw/include/pre-os/x86it/os/linux/tcp.h:96:0: 错误: "TCP_KEEPCNT" 重新定义 [-Werror] ../../../../zeromq/conf.x86it/../zeromq-4.0.1/../../../../routing- sw/include/pre-os/netinet/tcp.h:157:0: 注意：这里是前面定义的位置

../../../../zeromq/conf.x86it/../zeromq-4.0.1/../../../../routing-sw/include/pre-os/x86it/os/linux/tcp.h:24:8: error: redefinition of 'struct tcphdr' ../../../../zeromq/conf.x86it/../zeromq-4.0.1/../../../../routing-sw/include/pre-os/netinet/tcp.h:67:8: error: previous definition of 'struct tcphdr'

==========================

==========常量表达式再次出错==========

../../../../zeromq/conf.x86it/../zeromq-4.0.1/../../../../routing-sw/include/pre-os/x86it/os/linux/tcp.h:72:17: error: '__u32 __fswab32(__u32)' cannot appear in a constant-expression ../../../../zeromq/conf.x86it/../zeromq-4.0.1/../../../../routing-sw/include/pre-os/x86it/os/linux/tcp.h:72:17: error: a function call cannot appear in a constant-expression ../../../../zeromq/conf.x86it/../zeromq-4.0.1/../../../../routing-sw/include/pre-os/x86it/os/linux/tcp.h:73:17: error: '__u32 __fswab32(__u32)' cannot appear in a constant-expression

=============

似乎存在 cross 依赖项。有人遇到过这个问题吗？解决这个问题的方法是什么？

Answer 1

在CXXFLAGS中添加-std=c++0x后，编译顺利:

CXXFLAGS = -Wall           \
           -pipe            \
           -g                \
           -O2                \
           -fno-crossjumping   \
           -fno-strict-aliasing \
           -march=pentiumpro     \
           --sysroot=/auto/andpkg/rep_cache//wr-x86-xeon/5.0/sysroot/intel_xeon_32_core-wrs-linux \
           -m32                    \
           -Wno-variadic-macros     \
           -std=c++0x

'u32 fswab32(__u32)' 不能出现在 netinet/tcp_md5.h 的常量表达式中

'u32 fswab32(__u32)' cannot appear in a constant-expression in netinet/tcp_md5.h

linux

cross-compiling

zeromq

'__u32 __fswab32(__u32)' 不能出现在 netinet/tcp_md5.h 的常量表达式中

'__u32 __fswab32(__u32)' cannot appear in a constant-expression in netinet/tcp_md5.h

linux

cross-compiling

zeromq

'u32 fswab32(__u32)' 不能出现在 netinet/tcp_md5.h 的常量表达式中

'u32 fswab32(__u32)' cannot appear in a constant-expression in netinet/tcp_md5.h