-
Brad King authored
Internally we mark `file(GENERATE)` outputs as `GENERATED` in order to tell custom command dependency tracing logic not to expect the files to exist on disk yet. This is because we do not generate the files until after that tracing is done. The Ninja generator also interprets the `GENERATED` property to mean that it is expected that some build rule will generate the file if another build rule depends on it. If the generator does not know of a custom command that generates the file then it adds an empty one so that the `ninja` build tool does not complain about a dependency on a file that does not exist and has no rule to generate it. However, this step is not necessary for `file(GENERATE)` outputs because there is no build rule to generate them and they will exist before `ninja` runs. Add an additional `__CMAKE_GENERATED_BY_CMAKE` property internally to tell the Ninja generator that a `GENERATED` file will exist before the build starts and is not expected to have a build rule producing it. Fixes: #17942
0826c201