From 3165e3c2f42d56838c4c496c2717b3c2b4cb73fe Mon Sep 17 00:00:00 2001
From: Aditya Alok <dev.aditya.alok@gmail.com>
Date: Sun, 10 Apr 2022 01:41:30 +0530
Subject: [PATCH] feat(ghc-libs): link against libandroid-posix-semaphore

GHC unix lib uses `ccall` ffi which ignores include indirection. It
directly links against available symbols during compile.

Although, directly linking to `libandroid-posix-semaphore` should work
too, but that depends upon library load order during runtime, i.e if
`libc` is loaded before (very unlikely, unless LD_PRELOAD is set)
`libandroid-posix-semaphore`, it would use sem_{open,close,unlink} from
it, which isn't implemented.

So, to be sure that it always links against `libandroid-posix-semaphore`
symbols, I have patched it to use `capi` ffi which considers include
indirections.

Signed-off-by: Aditya Alok <dev.aditya.alok@gmail.com>
---
 packages/ghc-libs/build.sh        |  6 +++---
 packages/ghc-libs/semaphore.patch | 25 +++++++++++++++++++++++++
 2 files changed, 28 insertions(+), 3 deletions(-)
 create mode 100644 packages/ghc-libs/semaphore.patch

diff --git a/packages/ghc-libs/build.sh b/packages/ghc-libs/build.sh
index f1c9a498c..b5e08cb03 100644
--- a/packages/ghc-libs/build.sh
+++ b/packages/ghc-libs/build.sh
@@ -3,10 +3,10 @@ TERMUX_PKG_DESCRIPTION="The Glasgow Haskell Compiler - Dynamic Libraries"
 TERMUX_PKG_LICENSE="BSD 2-Clause, BSD 3-Clause, LGPL-2.1"
 TERMUX_PKG_MAINTAINER="Aditya Alok <dev.aditya.alok@gmail.com>"
 TERMUX_PKG_VERSION=8.10.7
-TERMUX_PKG_REVISION=2
+TERMUX_PKG_REVISION=3
 TERMUX_PKG_SRCURL="https://downloads.haskell.org/~ghc/${TERMUX_PKG_VERSION}/ghc-${TERMUX_PKG_VERSION}-src.tar.xz"
 TERMUX_PKG_SHA256=e3eef6229ce9908dfe1ea41436befb0455fefb1932559e860ad4c606b0d03c9d
-TERMUX_PKG_DEPENDS="iconv, libffi, ncurses, libgmp"
+TERMUX_PKG_DEPENDS="iconv, libffi, ncurses, libgmp, libandroid-posix-semaphore"
 TERMUX_PKG_BUILD_IN_SRC=true
 TERMUX_PKG_EXTRA_CONFIGURE_ARGS="
 --disable-ld-override
@@ -77,7 +77,7 @@ termux_step_pre_configure() {
 		SRC_HC_OPTS        = -O -H64m
 		GhcStage1HcOpts    = -O
 		GhcStage2HcOpts    = ${EXTRA_FLAGS}
-		GhcLibHcOpts       = ${EXTRA_FLAGS}
+		GhcLibHcOpts       = ${EXTRA_FLAGS} -optl-landroid-posix-semaphore
 		BuildFlavour       = quick-cross
 		GhcLibWays         = v dyn
 		STRIP_CMD          = ${STRIP}
diff --git a/packages/ghc-libs/semaphore.patch b/packages/ghc-libs/semaphore.patch
new file mode 100644
index 000000000..eb671ecc8
--- /dev/null
+++ b/packages/ghc-libs/semaphore.patch
@@ -0,0 +1,25 @@
+--- ghc-8.10.7/libraries/unix/System/Posix/Semaphore.hsc	2020-04-19 14:47:09.000000000 +0530
++++ ghc-8.10.7-patch/libraries/unix/System/Posix/Semaphore.hsc	2022-04-11 12:43:10.193206043 +0530
+@@ -3,6 +3,7 @@
+ #else
+ {-# LANGUAGE Trustworthy #-}
+ #endif
++{-# LANGUAGE CApiFFI #-}
+ -----------------------------------------------------------------------------
+ -- |
+ -- Module      :  System.Posix.Semaphore
+@@ -114,11 +115,11 @@
+                           cint <- peek ptr
+                           return $ fromEnum cint
+ 
+-foreign import ccall safe "sem_open"
++foreign import capi safe "semaphore.h sem_open"
+         sem_open :: CString -> CInt -> CMode -> CUInt -> IO (Ptr ())
+-foreign import ccall safe "sem_close"
++foreign import capi safe "semaphore.h sem_close"
+         sem_close :: Ptr () -> IO CInt
+-foreign import ccall safe "sem_unlink"
++foreign import capi safe "semaphore.h sem_unlink"
+         sem_unlink :: CString -> IO CInt
+ 
+ foreign import ccall safe "sem_wait"