Exploring Alternatives to VS_KEYWORD for Project Structure in CMake-Generated MSVC Projects

VS_KEYWORD in CMake

VS_KEYWORD is a special CMake property that's primarily used when generating project files for Microsoft Visual Studio (MSVC). It allows you to specify a keyword that will be associated with a particular target within the generated project. This keyword can then be used by MSVC to identify and manage the target in its own project structure.

How it Works

1. • You can set the VS_KEYWORD property for a target within your CMakeLists.txt file using the set_target_properties command:

     set_target_properties(my_target PROPERTIES VS_KEYWORD "MyCustomKeyword")
     

     In this example, the VS_KEYWORD property for the target my_target is set to "MyCustomKeyword".

2. Impact on MSVC Project Files
   

   • When CMake generates project files for MSVC, it typically creates a project configuration for each build configuration you've specified (e.g., Debug, Release). Within each configuration, CMake may create folders or groups to organize targets.

   • The specific behavior of how VS_KEYWORD is used in the generated project files depends on the version of MSVC and potentially other factors. Here are some common possibilities:

     • Project Configuration Folders
       MSVC might create a folder named after the VS_KEYWORD within the project configuration to group related files for that target.
     • Custom Properties
       MSVC might set a custom property on the target or its associated files that reflects the VS_KEYWORD value. This property can then be used by MSVC for various purposes, such as filtering or managing targets in the IDE.

Example: Customizing Project Structure

Suppose you have a CMake project with multiple targets, and you want to organize them differently within the generated MSVC project. You can use VS_KEYWORD to achieve this:

set_target_properties(executable1 PROPERTIES VS_KEYWORD "Executables")
set_target_properties(library2 PROPERTIES VS_KEYWORD "Libraries")

In this case, CMake might create folders named "Executables" and "Libraries" within each MSVC project configuration to group the respective targets. This can help improve the organization and clarity of your project in the MSVC IDE.

Key Points

• It can be used to customize the project structure and target management within MSVC.
• Its exact impact depends on MSVC version and other factors.
• VS_KEYWORD is specifically for MSVC project generation.

Additional Considerations

• For more advanced project organization in MSVC, you might consider using CMake's built-in folder organization features or custom project generators.
• If you're using CMake with other IDEs besides MSVC, VS_KEYWORD likely won't have any effect.

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Example 1: Basic Organization

This example shows how to use VS_KEYWORD to group an executable and a library target under separate folders in the generated MSVC project:

add_executable(my_executable main.cpp)
add_library(my_library library.cpp)

set_target_properties(my_executable PROPERTIES VS_KEYWORD "Executables")
set_target_properties(my_library PROPERTIES VS_KEYWORD "Libraries")

In this case, CMake might create folders named "Executables" and "Libraries" within each MSVC project configuration to hold the respective targets (my_executable and my_library).

Example 2: Customizing Folder Names

This example builds upon the previous one, but assigns more descriptive folder names using string manipulation:

set(EXECUTABLE_FOLDER_NAME "My Custom Executables")
set(LIBRARY_FOLDER_NAME "Internal Libraries")

add_executable(my_executable main.cpp)
add_library(my_library library.cpp)

set_target_properties(my_executable PROPERTIES VS_KEYWORD "${EXECUTABLE_FOLDER_NAME}")
set_target_properties(my_library PROPERTIES VS_KEYWORD "${LIBRARY_FOLDER_NAME}")

Here, CMake might create folders named "My Custom Executables" and "Internal Libraries" to organize the targets.

Example 3: Conditional Keyword Assignment

This example demonstrates setting VS_KEYWORD based on the build type (Debug or Release):

if(CMAKE_BUILD_TYPE STREQUAL "Debug")
  set(TARGET_KEYWORD_SUFFIX "_Debug")
else()
  set(TARGET_KEYWORD_SUFFIX "")
endif()

add_executable(my_program main.cpp)
set_target_properties(my_program PROPERTIES VS_KEYWORD "MyProgram${TARGET_KEYWORD_SUFFIX}")

In this case, the generated MSVC project might have a folder named "MyProgram" (for Release) or "MyProgram_Debug" (for Debug).

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CMake's Built-in Folder Organization

CMake provides built-in features for organizing targets within project files. You can use these features to achieve similar results as with VS_KEYWORD without relying on a specific MSVC property. Here are some options:

• Custom Targets
  Define custom targets to group related build steps or files. These targets won't be directly compiled but can help structure the project visually.

  add_custom_target(MyTarget ALL COMMAND echo "This is a custom target for grouping")
  
  add_executable(executable1 source1.cpp)
  add_executable(executable2 source2.cpp)
  
  add_dependencies(MyTarget executable1 executable2)  # Associate executables with the custom target
  

• CMAKE_CXX_FLAGS
  You can use compiler flags like /SUBSYSTEM:CONSOLE for console applications or /SUBSYSTEM:WINDOWS for GUI applications. MSVC might use these flags to categorize targets within the project.

  if(WIN32)
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /SUBSYSTEM:WINDOWS")
  else()
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /SUBSYSTEM:CONSOLE")
  endif()
  
  add_executable(my_gui_app main.cpp)
  

• SOURCE_GROUP
  This property allows you to assign a group name to a source file. Targets that depend on those files will inherit the group association. This helps organize files logically within the Solution Explorer in MSVC.

  set_source_files(SRC1 main.cpp)
  source_group(SOURCE_FILES MySourceGroup SRC1)
  
  add_executable(my_executable ${SRC1})
  

Custom Project Generators

For more advanced control over the generated MSVC project structure, you can create custom project generators. These are CMake scripts that write the specific project files desired. This approach requires more effort but offers maximum flexibility.

Refer to the CMake documentation for details on creating custom project generators:

Choosing the Right Approach

The best alternative depends on your specific needs and the level of control you require. If you just need basic organization, SOURCE_GROUP and CMAKE_CXX_FLAGS might be sufficient. However, for complex project structures, custom project generators offer the most flexibility.

Additional Considerations

• Consider project maintainability and clarity when choosing an approach.
• VS_KEYWORD can still be a valid option, especially if you need compatibility with older MSVC versions that might rely on it.