base- Basic libraries
Copyright(c) The University of Glasgow 2011
Licensesee libraries/base/LICENSE
Portabilitynon-portable (GHC Extensions)
Safe HaskellTrustworthy




Access to GHC's info-table provenance metadata.

The API of this module is unstable and not meant to be consumed by the general public. If you absolutely must depend on it, make sure to use a tight upper bound, e.g., base < 4.X rather than base < 5, because the interface can change rapidly without much warning.

Since: base-



data InfoProv Source #


Instances details
Show InfoProv Source # 
Instance details

Defined in GHC.InfoProv

Eq InfoProv Source # 
Instance details

Defined in GHC.InfoProv

whereFrom :: a -> IO (Maybe InfoProv) Source #

Get information about where a value originated from. This information is stored statically in a binary when `-finfo-table-map` is enabled. The source positions will be greatly improved by also enabled debug information with `-g3`. Finally you can enable `-fdistinct-constructor-tables` to get more precise information about data constructor allocations.

The information is collect by looking at the info table address of a specific closure and then consulting a specially generated map (by `-finfo-table-map`) to find out where we think the best source position to describe that info table arose from.

Since: base-