CMake Tools 1.4.0 doesn't define CMAKE_BUILD_TYPE in a project's build directory's CMakeCache.txt

[drfknoble]

Brief Issue Summary

I am using Visual Studio Code and CMake Tools to build a simple C++ project using OpenCV. The project relies on OpenCV's opencv_world430d.dll and OpenCV_world.dll files. To copy them to the build and install directory, I use an if statement to check whether the CMAKE_BUILD_TYPE matches either Debug or Release; then I define a variable equal to the path to the corresponding debug or release dll. Lastly, I use a custom command to copy the files to the build directory and install them to a desired install location. The problem is, CMAKE_BUILD_TYPE is not defined - even though I've configured the project and selected a Debug configuration.

Expected:

If build type is Debug, the syntax if(${CMAKE_BUILD_TYPE) MATCHES Debug) should return true; else, if build type is Release, the syntax if(${CMAKE_BUILD_TYPE) MATCHES Release) should return true.

It is expected that CMAKE_BUILD_TYPE is defined as either Debug or Release.

Apparent Behavior

CMAKE_BUILD_TYPE is not defined.

Platform and Versions

• Operating System: Windows 10
• CMake Version: 3.17.3
• VSCode Version: 1.45.1
• CMake Tools Extension Version: 1.4.0
• Compiler/Toolchain: Visual C++ 2019

Other Notes/Information

Looking in the project's build directory's CMakeCache.txt file, CMAKE_BUILD_TYPE is not included. When I use Visual Studio 2019, the project behaves as expected and CMAKE_BUILD_TYPE is included in the CMakeCache.txt file.

[drfknoble]

If you manually set the preferred generator to be "Ninja", then CMAKE_BUILD_TYPE is defined in the CMakeCache.txt file.

If no preferred generator is specified, Visual Studio is used as the generator and it doesn't specify CMAKE_BUILD_TYPE in the CMakeCache.txt file.

Given that Visual Studio may be the default for a lot of people, it'd be good if it, by default, added CMAKE_BUILD_TYPE to CMakeCache.txt. I'm not sure if it's a bug, a problem with my installation, or something I should do (but didn't know to do). Perhaps if someone can comment, then we can be sure which of these it is.

[jakoch]

Hi!

I think CMAKE_BUILD_TYPE isn't set by default in this case, because CMake supports two types of generators: single-configurations (makefiles, nmake) and multi-configurations (IDEs).

I suggest to add the following lines to settings.json.
This should then update your CMAKE_BUILD_TYPE accordingly and set it as -D CLI option.

"cmake.configureSettings": {
   "CMAKE_BUILD_TYPE": "${buildType}"
}

With this in the CMakeListst.txt to see, if var is set:

message(STATUS "CMAKE_BUILD_TYPE: ${CMAKE_BUILD_TYPE}")

[db4]

Looks like the problem is the CMake generator: for older CMake Tools it was Ninja but for 1.4.0 it's Visual Studio XXXX. The latter is a multi-configuration generator so CMake does not define CMAKE_BUILD_TYPE for it (CMake generator expressions supposed to be used instead)

I also need CMAKE_BUILD_TYPE in my build to I'm trying to use Ninja generator as I did before. No luck yet - any related vscode settings (cmake.preferredGenerators etc.) are just ignored. Any idea how to do that?

[bobbrow]

@db4, Are you saying that the Ninja generator is not defining the CMAKE_BUILD_TYPE? Have you reloaded the window/extension since you changed your generator? Sometimes the settings change doesn't automatically get applied. That's something we're investigating. #1127

[db4]

@db4, Are you saying that the Ninja generator is not defining the CMAKE_BUILD_TYPE?

Quite the opposite: Ninja generator defines CMAKE_BUILD_TYPE, Visual Studio XXXX does not.

[bobbrow]

So are you saying you can't get the extension to pick Ninja again? Did you set the cmake.generator or cmake.preferredGenerators settings?

[db4]

So are you saying you can't get the extension to pick Ninja again? Did you set the cmake.generator or cmake.preferredGenerators settings?

Well, I cannot reproduce the issue anymore - after upgrade to 1.4.1 and some cleanups cmake.generator=Ninja works as expected.

[xylr117z4]

VS Code has added a setting for Cmake which sets the build type on multi config generators (the default generator.)

if you open File > Preferences > Settings and search "CMAKE_" or "CMAKE_BUILD_TYPE" it'll be the first option to appear.

It'd be nice if this were the default, but well I'm not sure where we'd bug them about it... and well I can't be bothered to do that.

[xiaohaoo]

VS Code为Cmake添加了一个设置，它在多配置生成器（默认生成器）上设置构建类型。

如果你打开文件>首选项>设置并搜索“CMAKE_”或“CMAKE_BUILD_TYPE”，它将是第一个出现的选项。

如果这是默认的就好了，但是我不确定我们会在哪里打扰他们……我可不想这么做。

Good.

[benmcmorran]

We'll evaluate changing the default value of this setting in the 1.16 extension release.