Link problem with MinGW

[RookieCLY]

Is there an already existing issue for this?

• I have searched the existing issues

Expected behavior

I have already compile foonathan_memory, fastcdr and tinyxml2 with MinGW successfully. But there are some problem when I compile the fastdds with MinGW, like "i64 to LL","stat redefined","declspec( dllexport ) to attribute((visibility("default")))"...... I used some special means to solve these problems and finally successfully compiled fastdds, then i got libfastdds.dll and libfastdds.dll.a

Current behavior

But when I use libfastdds.dll and libfastdds.dll.a in my project, there are some thing wrong like
E:/mingw32-14/bin/../lib/gcc/i686-w64-mingw32/14.2.0/../../../../i686-w64-mingw32/bin/ld.exe: CMakeFiles\MBus.dir/objects.a(startlogPubSubTypes.cxx.obj):startlogPubSubTypes.cxx:(.text+0x5cd): undefined reference to eprosima::fastdds::MD5::MD5()'`......
All the symbol from FastDDS which i used in my project was undefined. I tried every import and export combination in fastdds_dll.hpp, "attribute((visibility("default")))" "declspec( dllexport )" "declspec( dllimport )" "null" . But does not work.
Are there some special export config for MinGW in FastDDS?

Steps to reproduce

1:Compile foonathan_memory, fastcdr and tinyxml2 with MinGW.
2:Modify the source code, like modify CMAKE_CXX_FLAGS, modify include in some files, and so on.
3:Use libfastdds.dll.a in your project.

Fast DDS version/commit

FastDDS v3.1.1 master
FastCDR v2.2.5
MinGW v14.2.0
Windows10

Platform/Architecture

Other. Please specify in Additional context section.

Transport layer

Default configuration, UDPv4 & SHM

Additional context

No response

XML configuration file

No response

Relevant log output

No response

Network traffic capture

No response

[Javgilavi]

Hi @RookieCLY,

Can you share more details on the errors that you had when compiling fastdds? And what were the "solution means" that you did?

[RookieCLY]

@Javgilavi
Yes, my pleasure. “solution means” can be divided into three parts.
First, warning with little impact. like "unused-parameter" "missing-field-initializers" and so on. I just use command like "-Wno-unused-parameter" to ignore them.
Then, some llibrary error between windows and unix. Added option for "elif defined(MINGW)" to ifdef _WIN32(or _MSC_VER) and else , then fill the MINGW branch, so it can work as same as the _WIN32(or _MSC_VER) branch. For example, in "RobustExclusiveLock.hpp", add "elif defined(MINGW)" to ifdef _MSC_VER and else in the "include" block and "class" block. Then copy the code from "_MSC_VER" block, use the same function "_sopen_s" with <io.h>(MinGW), modify "_SH_DENYRW" to "0x0010", which is not defined in <io.h>(MinGW).
Third, Manually link library, like "target_link_libraries(fastdds PUBLIC ws2_32 mswsock)".

As for the error in this issue, I solved this problem with "declspec( dllexport )" and "-Wno-attributes". So i can use almost all the symbols from libfastdds.dll and libfastdds.dll.a.
Why "almost all"? There are some new problem for "TypeSupport".
When I use TypeSupport(new startlogPubSubType()) to construct a TypeSupport object, i got the error
E:/mingw32-14/bin/../lib/gcc/i686-w64-mingw32/14.2.0/../../../../i686-w64-mingw32/bin/ld.exe: C:\Users\CUILIU~1\AppData\Local\Temp\ccEr7V0I.o:xmsgbus.cxx:(.text$_ZN8eprosima7fastdds3dds11TypeSupportC1EPNS1_13TopicDataTypeE[__ZN8eprosima7fastdds3dds11TypeSupportC1EPNS1_13TopicDataTypeE]+0x20): undefined reference tovtable for eprosima::fastdds::dds::TypeSupport' `
Maybe there are some thing wrong with "class TypeSupport : public std::shared_ptr<TopicDataType>" and MinGW?
By the way, "startlogPubSubType" was generated by fastdds-gen with a idl.