Portability | portable |
---|---|
Maintainer | cabal-devel@haskell.org |
This should be a much more sophisticated abstraction than it is. Currently
it's just a bit of data about the compiler, like it's flavour and name and
version. The reason it's just data is because currently it has to be in
Read
and Show
so it can be saved along with the LocalBuildInfo
. The
only interesting bit of info it contains is a mapping between language
extensions and compiler command line flags. This module also defines a
PackageDB
type which is used to refer to package databases. Most compilers
only know about a single global package collection but GHC has a global and
per-user one and it lets you create arbitrary other package databases. We do
not yet fully support this latter feature.
- module Distribution.Compiler
- data Compiler = Compiler {
- compilerId :: CompilerId
- compilerLanguages :: [(Language, String)]
- compilerExtensions :: [(Extension, String)]
- showCompilerId :: Compiler -> String
- compilerFlavor :: Compiler -> CompilerFlavor
- compilerVersion :: Compiler -> Version
- data PackageDB
- type PackageDBStack = [PackageDB]
- registrationPackageDB :: PackageDBStack -> PackageDB
- data OptimisationLevel
- flagToOptimisationLevel :: Maybe String -> OptimisationLevel
- type Flag = String
- languageToFlags :: Compiler -> Maybe Language -> [Flag]
- unsupportedLanguages :: Compiler -> [Language] -> [Language]
- extensionsToFlags :: Compiler -> [Extension] -> [Flag]
- unsupportedExtensions :: Compiler -> [Extension] -> [Extension]
Haskell implementations
module Distribution.Compiler
Compiler | |
|
Support for package databases
Some compilers have a notion of a database of available packages. For some there is just one global db of packages, other compilers support a per-user or an arbitrary db specified at some location in the file system. This can be used to build isloated environments of packages, for example to build a collection of related packages without installing them globally.
type PackageDBStack = [PackageDB]Source
We typically get packages from several databases, and stack them together. This type lets us be explicit about that stacking. For example typical stacks include:
[GlobalPackageDB] [GlobalPackageDB, UserPackageDB] [GlobalPackageDB, SpecificPackageDB "package.conf.inplace"]
Note that the GlobalPackageDB
is invariably at the bottom since it
contains the rts, base and other special compiler-specific packages.
We are not restricted to using just the above combinations. In particular we can use several custom package dbs and the user package db together.
When it comes to writing, the top most (last) package is used.
registrationPackageDB :: PackageDBStack -> PackageDBSource
Return the package that we should register into. This is the package db at the top of the stack.
Support for optimisation levels
data OptimisationLevel Source
Some compilers support optimising. Some have different levels. For compliers that do not the level is just capped to the level they do support.
Support for language extensions
unsupportedLanguages :: Compiler -> [Language] -> [Language]Source
extensionsToFlags :: Compiler -> [Extension] -> [Flag]Source
For the given compiler, return the flags for the supported extensions.
unsupportedExtensions :: Compiler -> [Extension] -> [Extension]Source
For the given compiler, return the extensions it does not support.