Compiler error of EthernetInterface + GCC ARM

When you compile a exported project that conotains EthernetInterface by GCC ARM ver 5.2 (2015/4q) or later, following error occurs.

In file included from ./EthernetInterface/Socket/Socket.h:21:0,
                 from ./EthernetInterface/Socket/TCPSocketConnection.h:22,
                 from ./EthernetInterface/EthernetInterface.h:84,
                 from main.cpp:2:
./EthernetInterface/lwip/include/lwip/sockets.h:311:8: error: redefinition of 's
truct timeval'
 struct timeval {
        ^
In file included from c:\program files\gnu tools arm embedded\5.2 2015q4\arm-non
e-eabi\include\sys\select.h:27:0,
                 from c:\program files\gnu tools arm embedded\5.2 2015q4\arm-non
e-eabi\include\sys\types.h:89,
                 from c:\program files\gnu tools arm embedded\5.2 2015q4\arm-non
e-eabi\include\stdio.h:48,
                 from c:\program files\gnu tools arm embedded\5.2 2015q4\arm-non
e-eabi\include\c++\5.2.1\cstdio:42,
                 from ./mbed/platform.h:27,
                 from ./mbed/mbed.h:21,
                 from main.cpp:1:
c:\program files\gnu tools arm embedded\5.2 2015q4\arm-none-eabi\include\sys\_ti
meval.h:51:8: error: previous definition of 'struct timeval'
 struct timeval {
        ^
Makefile:60: recipe for target `main.o' failed
make: *** [main.o] Error 1

The way to fix the error

following description is written in EthernetInterface\lwip\include\lwip\sockets.h(304).

/** LWIP_TIMEVAL_PRIVATE: if you want to use the struct timeval provided
 * by your system, set this to 0 and include <sys/time.h> in cc.h */ 

According to this description, you can fix this error by modifing following 2 files.

EthernetInterface\lwip\include\lwip\sockets.h(307)

#define LWIP_TIMEVAL_PRIVATE 1
     ↓
#define LWIP_TIMEVAL_PRIVATE 0

EthernetInterface\lwip-sys\arch\cc.h(35)

#include <stdint.h>
     ↓
#include <stdint.h>
#include <sys/time.h>

cause

In GCC ARM ver.5.2, <sys/select.h> is added to the system include file.
"struct timeval" is defined in this file, and this causes duplicate definition.

EterhnetInterface + GCC ARM でコンパイルエラー

EthernetInterfaceをimportしたプロジェクトをGCC ARMでexportし、 GCC ARMのver.5.2以降(2015/4q以降)でコンパイルすると、以下のコンパイルエラーが出力されます。

In file included from ./EthernetInterface/Socket/Socket.h:21:0,
                 from ./EthernetInterface/Socket/TCPSocketConnection.h:22,
                 from ./EthernetInterface/EthernetInterface.h:84,
                 from main.cpp:2:
./EthernetInterface/lwip/include/lwip/sockets.h:311:8: error: redefinition of 's
truct timeval'
 struct timeval {
        ^
In file included from c:\program files\gnu tools arm embedded\5.2 2015q4\arm-non
e-eabi\include\sys\select.h:27:0,
                 from c:\program files\gnu tools arm embedded\5.2 2015q4\arm-non
e-eabi\include\sys\types.h:89,
                 from c:\program files\gnu tools arm embedded\5.2 2015q4\arm-non
e-eabi\include\stdio.h:48,
                 from c:\program files\gnu tools arm embedded\5.2 2015q4\arm-non
e-eabi\include\c++\5.2.1\cstdio:42,
                 from ./mbed/platform.h:27,
                 from ./mbed/mbed.h:21,
                 from main.cpp:1:
c:\program files\gnu tools arm embedded\5.2 2015q4\arm-none-eabi\include\sys\_ti
meval.h:51:8: error: previous definition of 'struct timeval'
 struct timeval {
        ^
Makefile:60: recipe for target `main.o' failed
make: *** [main.o] Error 1

対応方法

EthernetInterface\lwip\include\lwip\sockets.h(304)に以下の記述があります。

/** LWIP_TIMEVAL_PRIVATE: if you want to use the struct timeval provided
 * by your system, set this to 0 and include <sys/time.h> in cc.h */ 

この記述どおり、以下2箇所の変更を行うことで、エラーを回避できます。

EthernetInterface\lwip\include\lwip\sockets.h(307)

#define LWIP_TIMEVAL_PRIVATE 1
     ↓
#define LWIP_TIMEVAL_PRIVATE 0

EthernetInterface\lwip-sys\arch\cc.h(35)

#include <stdint.h>
     ↓
#include <stdint.h>
#include <sys/time.h>

原因

GCC ARM ver.5.2より、標準ライブラリのインクルードファイルに<sys/select.h>が追加されました。
この中でtimeval構造体を定義しており、lwip内で定義しているtimeval構造体と重複定義となってしまうようです。