Install some default exception handlers and run the inner computation. Unless you want to handle exceptions yourself, you should wrap this around the top level of your program. The default handlers output the error message(s) to stderr and exit cleanly.

This function is no longer necessary, cleanup is now done by runGhc/runGhcT.

Run function for the Ghc monad.

It initialises the GHC session and warnings via initGhcMonad. Each call to this function will create a new session which should not be shared among several threads.

Any errors not handled inside the Ghc action are propagated as IO exceptions.

Run function for GhcT monad transformer.

It initialises the GHC session and warnings via initGhcMonad. Each call to this function will create a new session which should not be shared among several threads.

Initialise a GHC session.

If you implement a custom GhcMonad you must call this function in the monad run function. It will initialise the session variable and clear all warnings.

The first argument should point to the directory where GHC's library files reside. More precisely, this should be the output of ghc --print-libdir of the version of GHC the module using this API is compiled with. For portability, you should use the ghc-paths package, available at http://hackage.haskell.org/package/ghc-paths.

Parse command line arguments that look like files. First normalises its arguments and then splits them into source files and object files. A source file can be turned into a Target via guessTarget

Updates both the interactive and program DynFlags in a Session. This also reads the package database (unless it has already been read), and prepares the compilers knowledge about packages. It can be called again to load new packages: just add new package flags to (packageFlags dflags).

Returns a list of new packages that may need to be linked in using the dynamic linker (see linkPackages) as a result of new package flags. If you are not doing linking or doing static linking, you can ignore the list of packages returned.

Returns the program DynFlags.

Sets the program DynFlags. Note: this invalidates the internal cached module graph, causing more work to be done the next time load is called.

Returns a boolean indicating if preload units have changed and need to be reloaded.

Set the action taken when the compiler produces a message. This can also be accomplished using setProgramDynFlags, but using setLogAction avoids invalidating the cached module graph.

Get the DynFlags used to evaluate interactive expressions.

Set the DynFlags used to evaluate interactive expressions. Note: this cannot be used for changes to packages. Use setSessionDynFlags, or setProgramDynFlags and then copy the unitState into the interactive DynFlags.

Find the package environment (if one exists)

We interpret the package environment as a set of package flags; to be specific, if we find a package environment file like

clear-package-db
global-package-db
package-db blah/package.conf.d
package-id id1
package-id id2

we interpret this as

[ -hide-all-packages
, -clear-package-db
, -global-package-db
, -package-db blah/package.conf.d
, -package-id id1
, -package-id id2
]

There's also an older syntax alias for package-id, which is just an unadorned package id

id1
id2

Sets the targets for this session. Each target may be a module name or a filename. The targets correspond to the set of root modules for the program/library. Unloading the current program is achieved by setting the current set of targets to be empty, followed by load.

Returns the current set of targets

Add another target.

Remove a target

Attempts to guess what Target a string refers to. This function implements the --make/GHCi command-line syntax for filenames:

• if the string looks like a Haskell source filename, then interpret it as such
• if adding a .hs or .lhs suffix yields the name of an existing file, then use that
• otherwise interpret the string as a module name

Perform a dependency analysis starting from the current targets and update the session with the new module graph.

Dependency analysis entails parsing the import directives and may therefore require running certain preprocessors.

Note that each ModSummary in the module graph caches its DynFlags. These DynFlags are determined by the current session DynFlags and the OPTIONS and LANGUAGE pragmas of the parsed module. Thus if you want changes to the DynFlags to take effect you need to call this function again. In case of errors, just throw them.

Perform dependency analysis like in depanal. In case of errors, the errors and an empty module graph are returned.

Try to load the program. See LoadHowMuch for the different modes.

This function implements the core of GHC's --make mode. It preprocesses, compiles and loads the specified modules, avoiding re-compilation wherever possible. Depending on the backend (see backend field) compiling and loading may result in files being created on disk.

Calls the defaultWarnErrLogger after each compiling each module, whether successful or not.

If errors are encountered during dependency analysis, the module depanalE returns together with the errors an empty ModuleGraph. After processing this empty ModuleGraph, the errors of depanalE are thrown. All other errors are reported using the defaultWarnErrLogger.

Describes which modules of the module graph need to be loaded.

Inform GHC that the working directory has changed. GHC will flush its cache of module locations, since it may no longer be valid.

Note: Before changing the working directory make sure all threads running in the same session have stopped. If you change the working directory, you should also unload the current program (set targets to empty, followed by load).

Parse a module.

Throws a SourceError on parse error.

Typecheck and rename a parsed module.

Throws a SourceError if either fails.

Desugar a typechecked module.

Load a module. Input doesn't need to be desugared.

A module must be loaded before dependent modules can be typechecked. This always includes generating a ModIface and, depending on the DynFlags's backend, may also include code generation.

This function will always cause recompilation and will always overwrite previous compilation results (potentially files on disk).

The result of successful parsing.

The result of successful typechecking. It also contains the parser result.

The result of successful desugaring (i.e., translation to core). Also contains all the information of a typechecked module.

A CoreModule consists of just the fields of a ModGuts that are needed for the compileToCoreModule interface.

This is the way to get access to the Core bindings corresponding to a module. compileToCore parses, typechecks, and desugars the module, then returns the resulting Core module (consisting of the module name, type declarations, and function declarations) if successful.

Like compileToCoreModule, but invokes the simplifier, so as to return simplified and tidied Core.

Return the ModSummary of a module with the given name.

The module must be part of the module graph (see hsc_mod_graph and ModuleGraph). If this is not the case, this function will throw a GhcApiError.

This function ignores boot modules and requires that there is only one non-boot module with the given name.

Get the module dependency graph.

Return True <==> module is loaded.

Topological sort of the module graph

Calculate SCCs of the module graph, possibly dropping the hi-boot nodes The resulting list of strongly-connected-components is in topologically sorted order, starting with the module(s) at the bottom of the dependency graph (ie compile them first) and ending with the ones at the top.

Drop hi-boot nodes (first boolean arg)?

• False: treat the hi-boot summaries as nodes of the graph, so the graph must be acyclic
• True: eliminate the hi-boot nodes, and instead pretend the a source-import of Foo is an import of Foo The resulting graph has no hi-boot nodes, but can be cyclic

Container for information about a Module.

Request information about a loaded Module

The list of top-level entities defined in a module

Returns the instances defined by the specified module. Warning: currently unimplemented for package modules.

Retrieve module safe haskell mode

Looks up a global name: that is, any top-level name in any visible module. Unlike lookupName, lookupGlobalName does not use the interactive context, and therefore does not require a preceding setContext.