Distribution.Simple.BuildToolDepends

This modules provides functions for working with both the legacy "build-tools" field, and its replacement, "build-tool-depends". Prefer using the functions contained to access those fields directly.

Documentation

desugarBuildTool :: PackageDescription -> LegacyExeDependency -> Maybe ExeDependency

Desugar a "build-tools" entry into proper a executable dependency if possible.

An entry can be so desguared in two cases:

1. The name in build-tools matches a locally defined executable. The executable dependency produced is on that exe in the current package.
2. The name in build-tools matches a hard-coded set of known tools. For now, the executable dependency produced is one an executable in a package of the same, but the hard-coding could just as well be per-key.

The first cases matches first.

getAllToolDependencies :: PackageDescription -> BuildInfo -> [ExeDependency]

Get everything from "build-tool-depends", along with entries from "build-tools" that we know how to desugar.

This should almost always be used instead of just accessing the buildToolDepends field directly.

isInternal :: PackageDescription -> ExeDependency -> Bool

Does the given executable dependency map to this current package?

This is a tiny function, but used in a number of places.

This function is only sound to call on BuildInfos from the given package description. This is because it just filters the package names of each dependency, and does not check whether version bounds in fact exclude the current package, or the referenced components in fact exist in the current package.

This is OK because when a package is loaded, it is checked (in Check) that dependencies matching internal components do indeed have version bounds accepting the current package, and any depended-on component in the current package actually exists. In fact this check is performed by gathering the internal tool dependencies of each component of the package according to this module, and ensuring those properties on each so-gathered dependency.

version bounds and components of the package are unchecked. This is because we sanitize exe deps so that the matching name implies these other conditions.

getAllInternalToolDependencies :: PackageDescription -> BuildInfo -> [UnqualComponentName]

Get internal "build-tool-depends", along with internal "build-tools"

This is a tiny function, but used in a number of places. The same restrictions that apply to isInternal also apply to this function.