d2ad58f410
- Remove ncurses6.patch - it's not so easy ;) - Add remove-cur_term-usage.patch to remove the need to access the cur_term global which isn't available in the openSUSE ncurses6 build. OBS-URL: https://build.opensuse.org/request/show/336406 OBS-URL: https://build.opensuse.org/package/show/devel:languages:haskell/ghc?expand=0&rev=190
109 lines
4.8 KiB
Diff
109 lines
4.8 KiB
Diff
Subject: Remove use of cur_term global struct
|
|
From: Scott Bahling sbahling@suse.com
|
|
Date: 2015-10-04
|
|
|
|
With the move to ncurses6, it has been decided by the openSUSE
|
|
developer to build the library in threaded mode only. In threaded
|
|
mode, the global variables are protected and not exported.
|
|
|
|
ghc-terminfo was accessing (reading and writing) the cur_term
|
|
global so it doesn't work with the openSUSE threaded ncurses6
|
|
library. This is an attempt to remove the need to access cur_term
|
|
and rely only on the low-level functions.
|
|
|
|
First, cur_term was being set to a null pointer in order to force
|
|
ncurses setupterm() to return new struct instead of a copy of the
|
|
current when the terminal name is the same. Actually (and unfortunately)
|
|
setupterm() does not return the struct but rather set the global cur_term.
|
|
Reading the ncurses code, and the NEWS file, it appears that the
|
|
behavior of setupterm() had been changed quite some time ago, and no
|
|
longer returns a copy of the struct (internal 'reuse' option) (NEWS 20041127).
|
|
The code seems to confirm this, so setting cur_term to a null pointer
|
|
shouldn't really be required - we remove poke cur_term!
|
|
|
|
That's great, but the we still have the problem that setupterm() doesn't
|
|
return the terminal struct that is required later to setup the
|
|
cleanup routine of the Terminal type (del_curterm cterm). The only
|
|
function that appears to return the cur_term pointer is set_curterm()
|
|
which has the side effect of overwriting the current pointer in the
|
|
process :/ So, we call set_curterm() with a null pointer, retrieving
|
|
the former, cur_term pointer for our use in the cterm instance, and
|
|
then call set_curterm() again with the former pointer to set it
|
|
back again.... whew! Having looked at the ncurses set_curterm() code
|
|
it seems it handles a null pointer in the way we would need.
|
|
|
|
Later in the withCurTerm function we use virtually the same trick
|
|
to relieve the need to peek into the cur_term global. I'm not so
|
|
sure if this is Haskell correct code though.
|
|
|
|
Someone with more Haskell programming knowledge than me should review
|
|
this patch. It still needs to be tested as well.
|
|
|
|
---
|
|
diff -Nrup a/libraries/terminfo/System/Console/Terminfo/Base.hs b/libraries/terminfo/System/Console/Terminfo/Base.hs
|
|
--- a/libraries/terminfo/System/Console/Terminfo/Base.hs 2015-02-25 06:13:15.000000000 +0100
|
|
+++ b/libraries/terminfo/System/Console/Terminfo/Base.hs 2015-10-03 21:40:09.106028237 +0200
|
|
@@ -63,7 +63,6 @@ import Data.Typeable
|
|
data TERMINAL
|
|
newtype Terminal = Terminal (ForeignPtr TERMINAL)
|
|
|
|
-foreign import ccall "&" cur_term :: Ptr (Ptr TERMINAL)
|
|
foreign import ccall set_curterm :: Ptr TERMINAL -> IO (Ptr TERMINAL)
|
|
foreign import ccall "&" del_curterm :: FunPtr (Ptr TERMINAL -> IO ())
|
|
|
|
@@ -73,19 +72,12 @@ foreign import ccall setupterm :: CStrin
|
|
--
|
|
-- Throws a 'SetupTermError' if the terminfo database could not be read.
|
|
setupTerm :: String -> IO Terminal
|
|
-setupTerm term = bracket (peek cur_term) (poke cur_term) $ \_ ->
|
|
- withCString term $ \c_term ->
|
|
+setupTerm term = withCString term $ \c_term ->
|
|
with 0 $ \ret_ptr -> do
|
|
-- NOTE: I believe that for the way we use terminfo
|
|
-- (i.e. custom output function)
|
|
-- this parameter does not affect anything.
|
|
let stdOutput = 1
|
|
- {-- Force ncurses to return a new struct rather than
|
|
- a copy of the current one (which it would do if the
|
|
- terminal names are the same). This prevents problems
|
|
- when calling del_term on a struct shared by more than one
|
|
- Terminal. --}
|
|
- poke cur_term nullPtr
|
|
-- Call setupterm and check the return value.
|
|
setupterm c_term stdOutput ret_ptr
|
|
ret <- peek ret_ptr
|
|
@@ -93,7 +85,12 @@ setupTerm term = bracket (peek cur_term)
|
|
then throwIO $ SetupTermError
|
|
$ "Couldn't look up terminfo entry " ++ show term
|
|
else do
|
|
- cterm <- peek cur_term
|
|
+ -- There is no function to simply return the cur_term pointer.
|
|
+ -- We call set_curterm with nullPtr which will give us
|
|
+ -- the value of the old cur_term and then we set it back
|
|
+ -- again.
|
|
+ cterm <- set_curterm nullPtr
|
|
+ set_curterm cterm
|
|
fmap Terminal $ newForeignPtr del_curterm cterm
|
|
|
|
data SetupTermError = SetupTermError String
|
|
@@ -120,15 +117,10 @@ setupTermFromEnv = do
|
|
-- TODO: this isn't really thread-safe...
|
|
withCurTerm :: Terminal -> IO a -> IO a
|
|
withCurTerm (Terminal term) f = withForeignPtr term $ \cterm -> do
|
|
- old_term <- peek cur_term
|
|
- if old_term /= cterm
|
|
- then do
|
|
- _ <- set_curterm cterm
|
|
- x <- f
|
|
- _ <- set_curterm old_term
|
|
- return x
|
|
- else f
|
|
-
|
|
+ old_term <- set_curterm cterm
|
|
+ x <- f
|
|
+ set_curterm old_term
|
|
+ return x
|
|
|
|
----------------------
|
|
|