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dacd986f1b
This allows developers to control whether these diagnostics are considered errors when `-warnings-as-errors` is specified. Resolves rdar://157694667.
1.1 KiB
1.1 KiB
Missing module version (ModuleVersionMissing)
Warnings that indicate the compiler cannot resolve an #if canImport(<ModuleName>, _version: <version>) directive because the module found was not built with a -user-module-version flag.
Overview
Developers may conditionalize which code is active in a source file based on the module version number of an imported dependency module, like this:
import Dependency
#if canImport(Dependency, _version: 1.2)
// Use declarations introduced in version 1.2 of Dependency
#else
// ...
#endif
A dependency's module version must be established by passing the -user-module-version flag when compiling the sources of the dependency the module. If no -user-module-version flag was specified when the dependency module was built, then the compiler will warn that it cannot resolve the #if canImport directive:
warning: cannot find user version number for module 'Dependency'; version number ignored [#ModuleVersionMissing]
If this diagnostic is emitted, then the #if canImport directive implicitly evaluates true.