{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE Strict            #-}
module Tokstyle.Linter.FuncPrototypes (descr) where

import           Control.Monad.State.Strict  (State)
import qualified Control.Monad.State.Strict  as State
import           Data.Fix                    (Fix (..))
import           Data.Text                   (Text)
import qualified Data.Text                   as Text
import           Language.Cimple             (Lexeme, Node, NodeF (..))
import           Language.Cimple.Diagnostics (CimplePos, Diagnostic)
import           Language.Cimple.TraverseAst (AstActions, astActions, doNode,
                                              traverseAst)
import           Tokstyle.Common             (warn)


linter :: AstActions (State [Diagnostic CimplePos]) Text
linter :: AstActions (State [Diagnostic CimplePos]) Text
linter = AstActions (State [Diagnostic CimplePos]) Text
forall (f :: * -> *) text. Applicative f => AstActions f text
astActions
    { doNode :: FilePath
-> Node (Lexeme Text)
-> State [Diagnostic CimplePos] ()
-> State [Diagnostic CimplePos] ()
doNode = \FilePath
file Node (Lexeme Text)
node State [Diagnostic CimplePos] ()
act ->
        case Node (Lexeme Text) -> NodeF (Lexeme Text) (Node (Lexeme Text))
forall (f :: * -> *). Fix f -> f (Fix f)
unFix Node (Lexeme Text)
node of
            FunctionPrototype Node (Lexeme Text)
_ Lexeme Text
name [] -> do
                FilePath -> Lexeme Text -> Text -> State [Diagnostic CimplePos] ()
forall diags at.
(HasDiagnosticsRich diags CimplePos,
 HasDiagnosticInfo at CimplePos) =>
FilePath -> at -> Text -> DiagnosticsT diags ()
warn FilePath
file Lexeme Text
name Text
"empty parameter list must be written as `(void)`"
                State [Diagnostic CimplePos] ()
act

            FunctionDefn{} -> () -> State [Diagnostic CimplePos] ()
forall (m :: * -> *) a. Monad m => a -> m a
return ()
            NodeF (Lexeme Text) (Node (Lexeme Text))
_ -> State [Diagnostic CimplePos] ()
act
    }

analyse :: (FilePath, [Node (Lexeme Text)]) -> [Diagnostic CimplePos]
analyse :: (FilePath, [Node (Lexeme Text)]) -> [Diagnostic CimplePos]
analyse = [Diagnostic CimplePos] -> [Diagnostic CimplePos]
forall a. [a] -> [a]
reverse ([Diagnostic CimplePos] -> [Diagnostic CimplePos])
-> ((FilePath, [Node (Lexeme Text)]) -> [Diagnostic CimplePos])
-> (FilePath, [Node (Lexeme Text)])
-> [Diagnostic CimplePos]
forall b c a. (b -> c) -> (a -> b) -> a -> c
. (State [Diagnostic CimplePos] ()
 -> [Diagnostic CimplePos] -> [Diagnostic CimplePos])
-> [Diagnostic CimplePos]
-> State [Diagnostic CimplePos] ()
-> [Diagnostic CimplePos]
forall a b c. (a -> b -> c) -> b -> a -> c
flip State [Diagnostic CimplePos] ()
-> [Diagnostic CimplePos] -> [Diagnostic CimplePos]
forall s a. State s a -> s -> s
State.execState [] (State [Diagnostic CimplePos] () -> [Diagnostic CimplePos])
-> ((FilePath, [Node (Lexeme Text)])
    -> State [Diagnostic CimplePos] ())
-> (FilePath, [Node (Lexeme Text)])
-> [Diagnostic CimplePos]
forall b c a. (b -> c) -> (a -> b) -> a -> c
. AstActions (State [Diagnostic CimplePos]) Text
-> (FilePath, [Node (Lexeme Text)])
-> State [Diagnostic CimplePos] ()
forall text a (f :: * -> *).
(TraverseAst text a, Applicative f) =>
AstActions f text -> a -> f ()
traverseAst AstActions (State [Diagnostic CimplePos]) Text
linter

descr :: ((FilePath, [Node (Lexeme Text)]) -> [Diagnostic CimplePos], (Text, Text))
descr :: ((FilePath, [Node (Lexeme Text)]) -> [Diagnostic CimplePos],
 (Text, Text))
descr = ((FilePath, [Node (Lexeme Text)]) -> [Diagnostic CimplePos]
analyse, (Text
"func-prototypes", [Text] -> Text
Text.unlines
    [ Text
"Checks that empty parameter lists in C functions are written as `(void)`."
    , Text
""
    , Text
"**Reason:** old-style empty parameter lists written as `()` are risky, because"
    , Text
"C interprets them as variadic. GCC warns about this but sometimes misses one."
    ]))