How to remove tokens from a list in cmake?

Question

I want to exclude some source files from building when not in Windows.
What is wrong in the following CMakeLists.txt cmake file?

aux_source_directory(. SRC_LIST)

# Remove Microsoft specific files
message(${SRC_LIST})

list(REMOVE_ITEM SRC_LIST stdafx.h stdafx.cpp)

message("------------------")
message(${SRC_LIST})

The contents of the messages before and after trying to remove the two files are exactly the same.

What is wrong?

Answer 1

You have to specify the exact name of the element you want to remove.

In your case, aux_source_directory prepends each entry with a ./, so the correct command has to be

list(REMOVE_ITEM SRC_LIST ./stdafx.h ./stdafx.cpp)

Also, please make sure you understand the implications of using manual calls to aux_source_directory for maintaining lists of source files:

It is tempting to use this command to avoid writing the list of source files for a library or executable target. While this seems to work, there is no way for CMake to generate a build system that knows when a new source file has been added. Normally the generated build system knows when it needs to rerun CMake because the CMakeLists.txt file is modified to add a new source. When the source is just added to the directory without modifying this file, one would have to manually rerun CMake to generate a build system incorporating the new file.

Quoting the documentation for aux_source_directory.