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| author | Ben Gamari <ben@smart-cactus.org> | 2023-04-12 11:40:39 -0400 |
|---|---|---|
| committer | Ben Gamari <ben@smart-cactus.org> | 2023-05-10 13:53:40 -0400 |
| commit | a02756b537b75acba0942381789850662ed6eab3 (patch) | |
| tree | 334407c83ce12f2275bf86f810f990cb3bba9513 /docs/users_guide/debugging.rst | |
| parent | 37f7aaa85f2da971fd2d430054e42449b596b4de (diff) | |
| download | haskell-wip/orig-thunk-info.tar.gz | |
compiler: Record original thunk info tables on stackwip/orig-thunk-info
Diffstat (limited to 'docs/users_guide/debugging.rst')
| -rw-r--r-- | docs/users_guide/debugging.rst | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/docs/users_guide/debugging.rst b/docs/users_guide/debugging.rst index e2acac340f..a972cb8ff0 100644 --- a/docs/users_guide/debugging.rst +++ b/docs/users_guide/debugging.rst @@ -1072,6 +1072,18 @@ Checking for consistency cases. This is helpful when debugging demand analysis or type checker bugs which can sometimes manifest as segmentation faults. +.. ghc-flag:: -forig-thunk-info + :shortdesc: Generate ``stg_orig_thunk_info`` stack frames on thunk entry + :type: dynamic + + When debugging cyclic thunks it can be helpful to know the original + info table of a thunk being evaluated. This flag enables code generation logic + to facilitate this, producing a ``stg_orig_thunk_info`` stack frame alongside + the usual update frame; such ``orig_thunk`` frames have no operational + effect but capture the original info table of the updated thunk for inspection + by debugging tools. See ``Note [Original thunk info table frames]`` in + ``GHC.StgToCmm.Bind`` for details. + .. ghc-flag:: -fcheck-prim-bounds :shortdesc: Instrument array primops with bounds checks. :type: dynamic |