Copyright | (c) The University of Glasgow 2011 |
---|---|
License | see libraries/base/LICENSE |
Maintainer | ghc-devs@haskell.org |
Stability | internal |
Portability | non-portable (GHC Extensions) |
Safe Haskell | Trustworthy |
Language | Haskell2010 |
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-4.18.0.0
Documentation
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-4.16.0.0
Internals
data InfoProvEnt Source #