![]() ![]() gitignore) suited exactly for your personal needs. You can create a user-local CMakeUserPresets.json file (put it in your. Actually, CMake's Preset feature sounds right up your alley. Note that most shells have history functionality, so you can recall past commands you've executed. The advantage is not having to remember and/or copy and paste long directory names every time I call cmake If the variable is a boolean, there's a shorthand command for defining a cache variable: option. ![]() I've written about this also in my answer to "CMakePresets.json vs CMakeSettings.json vs CMakeLists.txt". ) to conditionally only set the variable hasn't been set yet. Note that for potentially non-cache variables, you can do similar using if(DEFINED. Generally speaking, if the variable is something that you think someone building your project might want to have control over, then you should leave it to the user to use -D, and set a "default value" in your CMakeLists.txt by using set(. You can specify a type, and also a docstring.īoth cache and non-cache variables can be referenced using the same syntax ( docs and related nuance: policy CMP0126). Non-cache variables are scoped to blocks, functions, and directory scopes ( docs). You can also set the type using the TYPE argument. You can pass CACHE to set the variable as a cache variable. If you set the type to PATH or FILEPATH, the value will be converted to an absolute path. D sets variables as cache variables (see also Mastering CMake chapter, and variables docs), which means that even though they aren't set in the configuration files, they will be remembered. Note: My question does not have a specific context but was inspired by following this pytorch tutorial to setup my first C++ project and use pytorch. This answer provides a use case where the two methods are not the same, but is for some specific variable and library I have no knowledge of so can't relate to: Setting "-D" variables inside CMake This answer talks about scope of variables in cmake, and may contain the answer to my question, but it is too convoluted for me to follow: What's the CMake syntax to set and use variables? My question is what is the functional difference between the two methods, and what are some simple use cases where I might not want to use set instead of the command line -D flag? Related Questions The advantage is not having to remember and/or copy and paste long directory names every time I call cmake -DVARIABLE_NAME=path/to/infinity/and/beyond. The CMake docs splits expressions into Informational, Logical, and Output.Rather than using the command line and the -D flag to set variables, I've been using set() inside the CMakeLists.txt for my simple "learner" one-directory project. They act as if they are evaluated at build/install time, though actually they are evaluated for each build configuration. You can mix it with the positional arguments listed above any remaining arguments (therefore optional positional arguments) are in COMPLEX_PREFIX_UNPARSED_ARGUMENTS. If you look at the official page, you'll see a slightly different method using set to avoid explicitly writing the semicolons in the list feel free to use the structure you like best. Inside the function after this call, you'll find: COMPLEX_PREFIX_SINGLE = TRUEĬOMPLEX_PREFIX_MULTI_VALUES = "some other values" There are a series of all caps keywords you can use inside an if statement, and you can often refer to variables by either directly by name or using the $Ĭomplex(SINGLE ONE_VALUE value MULTI_VALUES some other values) CMake has an if statement, though over the years it has become rather complex. ![]()
0 Comments
Leave a Reply. |