CMAKE cpp compiler not working

[rdos314]

Here is the current rule:

# C++ compile a file into an object file
set(CMAKE_CXX_COMPILE_OBJECT
  "<CMAKE_CXX_COMPILER> ${CMAKE_WCL_QUIET} -d+ <DEFINES> <INCLUDES> <FLAGS> -fo<OBJECT> -c -cc++ <SOURCE>")

However, this doesn't work since wpp386 doesn't understand the -c compiler switch.

It should look something like this:

set(CMAKE_CXX_COMPILE_OBJECT
    "<CMAKE_CXX_COMPILER> <SOURCE> -fo=<OBJECT> <DEFINES> <INCLUDES> <FLAGS> "

[rdos314]

The static library generation rule doesn't seem to be correct either:

# C create a static library
set(CMAKE_C_CREATE_STATIC_LIBRARY
  "<CMAKE_AR> ${CMAKE_LIB_QUIET} -c -n -b <TARGET_QUOTED> <LINK_FLAGS> <OBJECTS> ")

However, the object files must be added with "+". Another issue is the use of -c, which means case sensitive, and this should be passed if needed, not as standard. Flags should not be link flags, since thouse will include things that wlib cannot handle. A better approach would be:

# C create a static library
set(CMAKE_C_CREATE_STATIC_LIBRARY
  "<CMAKE_AR> ${CMAKE_LIB_QUIET}  -n -b <TARGET> <FLAGS> +<OBJECTS> ")

[jmalak]

If I remember correctly then Watcom and Open Watcom CMake support uses historically wcl386 utility not C or C++ compiler directly therefore it uses some different options then C/C++ compiler and behaviour is little bit different. It uses all objects as space separated list not require +.
Anyway it is CMake issue not OW. Watcom CMake stuff is not part of OW we only refer use of OW with CMake.
You can submit any change to CMake to CMake development repository.

[jmalak]

I'm a bit surprised because this has been tested on several projects and there was no problem with the static or dynamic libraries being created.
If I remember correctly, the problem is with the CMake logic of how static and dynamic libraries are used in CMake projects.
Anyway, it's a bit confusing and looks like bad parameters, but be careful because it's a more complex hierarchy of parameters and modes. There is a difference between *NIX systems using the "ar" utility and OW using wlib. I cannot remember how static import library is created, if by wlib or by wlink, it should be taken into account too.
You're right that the wlib -c option shouldn't be there, but what's the point of making a static library without the -c option?

[rdos314]

I notice that the Watcom IDE use wpp386 to compile C++ code, and I need to move projects from the IDE to CMake. Will it work to pass the arguments from Watcom IDE to wcc386 instead, and give wcc386 as the CXX compiler for CMake? I modified my local Openwatcom.cmake like this:

set(CMAKE_CXX_COMPILER_OBJECT "<CMAKE_CXX_COMPILER> ${CMAKE_WCL_QUIET} <SOURCE> -fo=<OBJECT> <DEFINES> <INCLUDES> <FLAGS>")

Now my simple C++ test program for RDOS builds correctly. I use wpp386 as the CXX compiler.

I don't have write access to the CMAKE project, and I also think we should agree on how the CPP compiler is best supported.

[jmalak]

I think that it is not possible to use C++ compiler this way with CMake OW default stuff and it is useless also.
Even if it is possible to change CMake OW stuff to not use wcl386 and use separated C and C++ compiler but it is not simple due to CMake backward compatibility. It will require completely new CMake OW stuff based on direct usage of C and C++ compilers.
Anyway you not need too much change because most of C++ compiler options are directly passed by wcl386 to wpp386.
The wpp386 you can call by "wcl386 -c -cc++", it is what CMake uses and for wcc386 call "wcl386 -c -cc".
Anyway you have to transform the IDE project into a CMake script somehow. Most of options are same for wcl386 as for wpp386 may be only a few is different.
I don't understand why you don't use existing CMake stuff which works correctly with C and C++ compiler, you don't need such override as you use.

If you have any problem with existing CMake OW "Default" stuff then show some example of your problem.

I worked last time on CMake script to build WolfSSL with OW there is nothing magic.