ucsd-progsys/liquidhaskell

Specs not exported from preprocessed source code

Open

#2,132 opened on 2023年1月1日

GitHub で見る
 (3 comments) (0 reactions) (0 assignees)Haskell (1,306 stars) (157 forks)batch import
good first issue

説明

Consider the following example, where the source for the A module is preprocessed with hsc2hs:

# A.hsc
module A where

{-@ type Foo = { v : Int | v = 5 } @-}

# B.hs
module B where

import A

{-@ foo :: Foo @-}
foo = 5

LH fails with the following error:

[1 of 2] Compiling A

**** LIQUID: SAFE (0 constraints checked) **************************************
[2 of 2] Compiling B
ghc: panic! (the 'impossible' happened)
  (GHC version 8.10.7:
	[src/B.hs:5:12-14 Unknown type constructor `Foo`
                     matchTyCon: Foo]

If A.hsc is renamed to A.hs instead, then everything works fine. This problem might be hsc2hs-specific, but I suspect it's a more general problem with preprocessed source code.

Version of LH used: 0.8.10.7 (latest release on Hackage at time of writing)

コントリビューターガイド

技術スタック
なし
領域
toolingbuild system
Issue 種別
bug
難度新しい貢献者にとっての実装難度です。1 は非常に小さな変更、5 は専門的な作業です。
3
推定時間経験ある貢献者が調査、実装、テスト、pull request 準備にかけるおおよその時間範囲です。
half day
活動状況Issue が今どれだけ取り組みやすいかを示します。新しい、活発、古い、ブロック中、またはメンテナー入力待ちなどです。
stale
明確さ期待される変更、受け入れ条件、次の手順がどれだけ明確かを示します。
clear
前提条件
Knowledge of HaskellFamiliarity with LiquidHaskellUnderstanding of hsc2hs preprocessing
初心者向け度初回貢献者にどれだけ取り組みやすいかを 1-100 で推定したスコアです。
35
調査方針
Investigate how LiquidHaskell processes preprocessed source files like .hsc. Look at the code in the liquidhaskell repository, particularly the modules handling GHC plugin operations and interface generation. The difference between .hsc and .hs suggests a parsing or file extension handling issue. Check if the preprocessing step affects the export of liquid type specifications. Start by examining the 'src/' directory for files that deal with source preprocessing and type export. Document findings in a comment on the issue and consider reaching out to maintainers for further guidance.