Cmake file exists check

It essentially was a big CMake framework that first collected info about every module, looked at the dependencies between them and the needed libraries and then build targets manually for a module by linking explicitly everything that module needed.

The whole thing was implemented in a collection of complicated macros. There maps and lists and algorithms and directory traversals and everything you can imagine. The whole thing is written in CMake of course. Legacy code for the win! At one point I was considering building a similar system myself for my personal projects. Nothing adequately clicked with me. This went on for some while. Finally, a very fortunate thing happened.

I watched Applied Best Practices and decided to check out the repository. I still did some adjustments but I am still grateful that I found this project. Here I will go over the elements of the structure of the template project that I created. For by CMake structure I wanted at least some attempt to make external dependency management a little bit easier. The open-source, decentralized and multi-platform package manager to create and share all your native binaries.

I believe this here is just enough to set you up and give you some basics of how Conan does its magic. Conan can be installed through pip and there is an official get started guide.

Once everything is set up properly, you can write your conanfile. This is where all of your dependencies are defined.

An example file is:. It is a conf file with several sections. The dependencies go in the requires node. Usually what to put there is defined on the page of each Conan package. The generators section defines exactly what Conan does and how it builds the dependencies configuration files.

Different generators have different effects and use cases. With this configuration setup, you can later include several lines of CMake code in your top-level CMakeLists.

In theory at least. Sometimes things are a little bit tricky to get them running. This includes all of the CMake targets defined for Clara. We can later effortlessly link agings them when defining our executable for example. With Conan out of the way, I can now proceed to the pure CMake part of my project structure.

At the start, I want to layout my key core design goals. Determines which operating system and executable format the files are built for. This could be one of several values:.

Determines the tool to use for dependency resolution. Determines the path to the tool to use for dependency resolution. This is the actual path to objdump , dumpbin , or otool. If the file does not exist, it will be created. Create a file with no content if it does not yet exist. If a file does not exist it will be silently ignored. Generate an output file for each build configuration supported by the current CMake Generator. Evaluate generator expressions from the input content to produce the output content.

Generate the output file for a particular configuration only if the condition is true. The condition must be either 0 or 1 after evaluating generator expressions. Changed in version 3. See policy CMP Specify the output file name to generate. Multiple configurations may generate the same output file only if the generated content is identical.

Specify which target to use when evaluating generator expressions that require a target for evaluation e. Specify the newline style for the generated file.

Generated files are modified and their timestamp updated on subsequent cmake runs only if their content is changed. Use the content given explicitly as input.

Restrict variable replacement to references of the form VAR. Specify the newline style for the output file. Globbing expressions are similar to regular expressions, but much simpler. On Windows and macOS, globbing is case-insensitive even if the underlying filesystem is case-sensitive both filenames and globbing expressions are converted to lowercase before matching.

On other platforms, globbing is case-sensitive. If any of the outputs change, CMake will regenerate the build system. We do not recommend using GLOB to collect a list of source files from your source tree.

If no CMakeLists. Remove the given files. No error is emitted if a given file does not exist. Thanks, although it seems a lot of work just to check for a file : — gimmeamilk. I understand this works, but I agree with gimmeamilk it is tedious for such a simple thing.

Still, I will vote up the solution. May be, it would be worth to emphasize that your answer provides a portable solution. That's why I might be a bit sensitive concerning this. Stephen Stephen 1 1 silver badge 6 6 bronze badges. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. The the book provides the following snippet:. The script checks if the requested components are installed by checking if the corresponding export file exist.

This works only for components that include an exported target. My current solution would be to force the creation of an empty export set with an install script, but that looks very wrong.