haskell-stack-trace-plugin: haskell-stack-trace-plugin

[ compiler-plugin, debug, development, library, mit, program ] [ Propose Tags ]

This plugin allow implicitly add HasCallStack class to every top-level function for all module. Hence, we can to get completely continuous call stack.


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Versions [RSS] [faq] 0.1.0.0, 0.1.1.0, 0.1.1.1, 0.1.2.0, 0.1.3.0
Change log CHANGELOG.md
Dependencies base (>=4.12 && <4.16), ghc (==8.6.* || ==8.8.* || ==8.10.* || ==9.0.*), haskell-stack-trace-plugin [details]
License MIT
Copyright 2018-2021 Shinya Yamaguchi
Author Shinya Yamaguchi
Maintainer a@wado.dev
Category Compiler Plugin, Development, Debug
Home page https://github.com/waddlaw/haskell-stack-trace-plugin
Bug tracker https://github.com/waddlaw/haskell-stack-trace-plugin/issues
Source repo head: git clone git://github.com/waddlaw/haskell-stack-trace-plugin
Uploaded by waddlaw at 2021-05-25T03:22:00Z
Distributions NixOS:0.1.3.0
Executables example
Downloads 1034 total (13 in the last 30 days)
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Status Hackage Matrix CI
Docs available [build log]
Last success reported on 2021-05-25 [all 1 reports]

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Readme for haskell-stack-trace-plugin-0.1.3.0

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haskell-stack-trace-plugin

Hackage

This plugin allow implicitly add HasCallStack class to every top-level function for all module. Hence, we can to get completely continuous call stack.

  1. (implicitly) Import GHC.Stack for all modules.
  2. Add HasCallStack constraint for all top-level functions.

Requirement: (8.6 <= on GHC)

Synopsis

module Main where

import Data.Maybe (fromJust)

main :: IO ()
main = print f1

f1 :: Int
f1 = f2

f2 :: Int
f2 = f3

-- HsQualTy
f3 :: HasCallStack => Int
f3 = f4 0

-- HsQualTy
f4 :: Show a => a -> Int
f4 n = f5 (show n) 0

-- HsFunTy
f5 :: String -> Int -> Int
f5 _ _ = head f6

-- HsListTy
f6 :: [Int]
f6 = [fst f7]

-- HsTupleTy
f7 :: (Int, Int)
f7 = (fromJust f8, fromJust f8)

-- HsAppTy
f8 :: Maybe Int
f8 = Just f9

f9 :: Int
f9 = f10
  where
    f10 :: Int
    f10 = fError

-- HsTyVar
fError :: Int
fError = error "fError"

This example get error:

$ cabal build
example/Main.hs:15:7: error:
    Not in scope: type constructor or class ‘HasCallStack’
   |
15 | f3 :: HasCallStack => Int
   |       ^^^^^^^^^^^^

Yes, add import GHC.Stack to above example.

Fix and rebuild!

$ cabal run example -v0
example: fError
CallStack (from HasCallStack):
  error, called at example/Main.hs:47:10 in main:Main

Hmm, it is not useful. But, you will to be happy when enable this plugin.

  ghc-options:
    -fplugin=StackTrace.Plugin
$ cabal run example -v0
example: fError
CallStack (from HasCallStack):
  error, called at example/Main.hs:47:10 in main:Main
  fError, called at example/Main.hs:43:11 in main:Main
  f10, called at example/Main.hs:40:6 in main:Main
  f9, called at example/Main.hs:37:11 in main:Main
  f8, called at example/Main.hs:33:16 in main:Main
  f7, called at example/Main.hs:29:11 in main:Main
  f6, called at example/Main.hs:25:15 in main:Main
  f5, called at example/Main.hs:21:8 in main:Main
  f4, called at example/Main.hs:17:6 in main:Main
  f3, called at example/Main.hs:13:6 in main:Main
  f2, called at example/Main.hs:10:6 in main:Main
  f1, called at example/Main.hs:7:14 in main:Main
  main, called at example/Main.hs:7:1 in main:Main

Great!!!