Compile and link two files using cmake?

Question

I have two files in my project.
One is a ".c" file, one is a ".asm" file. First, I compile both the files into two ".o" object files and then link together using a custom linker script.
Currently, I am using a simple bash script with manual commands to build the project, but as the project size is expected to increase, I was thinking of moving the project to using cmake as its primary build system.

I have searched documentation of cmake and googled for a lot of time, although I have shortlisted some of the variables in cmake which might prove to be useful in this case, I am unable to find any sample explaining how to achieve this.

Can anybody provide me with a brief sample code on how should I go about achieving this ?

I had two problems, one is compiling assembly but I think I figured it out, so the main problem is the linking part. — Pratik Singhal, Sep 18 '14 at 14:49

randomusername · Accepted Answer · 2014-09-18T16:08:06.077

You asked for an example? Here's one from the cmake wiki

set(mySrcs foo.c bar.c)

set(can_use_assembler FALSE)

# test wether it is a x86 machine and as/gas is available
if("${CMAKE_SYSTEM_PROCESSOR}" MATCHES "i.86")
   enable_language(ASM-ATT)
   if(CMAKE_ASM-ATT_COMPILER_WORKS)
      set(can_use_assembler TRUE)
      set(mySrcs ${mySrcs} codec_i86.s)
   endif(CMAKE_ASM-ATT_COMPILER_WORKS)
endif("${CMAKE_SYSTEM_PROCESSOR}" MATCHES "i.86")

# no assembler found
if(not can_use_assembler)
   set(mySrcs ${mySrcs} codec_generic.c)
endif(not can_use_assembler)

add_executable(player ${mySrcs})

Because of the way that CMake works, assembling and linking are grouped together in the same step (from the programmer's perspective at least). So add_executable automatically handles everything for you.

If you want to include a linker script, that gets more difficult with CMake. The best place to look into it is over here. Since the examples and instructions are too long to copy out in the SO answer box, I'll leave the reading to you.

This doesn't answer the linking part, also I told in the comments already that I have handled the assembly compilation part. — Pratik Singhal, Sep 18 '14 at 16:05
@ps06756 See My edit on how to add a linker script. It's quite annoying and is definitely something that kitware should solve in the near future. — randomusername, Sep 18 '14 at 16:12

Compile and link two files using cmake?

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