Remove <sys/sem.h>

System V semaphores doesn't work for non-root, it's better to
point at unnamed POSIX semaphores in <semaphore.h>

README.md

@@ -126,9 +126,8 @@ Common porting problems
 * Android uses a customized version of shared memory managemnt known as ashmem. libandroid-shmem wraps SYSV shared
   memory calls to standard ashmem operations. Use it with `LDFLAGS+=" -landroid-shmem`.
 
-* SYSV semaphore libc wrappers (semget(2), semop(2) and others) aren't available. Direct syscalls can be used with
-  `CFLAGS+=" -DTERMUX_SEMOPS_STUBS=1"`. Using this requires privelege escalation i.e. only root can do it. Use
-  unnamed POSIX semaphores instead (named semaphores are unimplemented).
+* SYSV semaphores (semget(2), semop(2) and others) aren't available.
+  Use unnamed POSIX semaphores instead (named semaphores are unimplemented).
 
 dlopen() and RTLD_* flags
 =================================

build-package.sh

@@ -218,7 +218,7 @@ termux_step_setup_variables() {
 	TERMUX_STANDALONE_TOOLCHAIN="$TERMUX_TOPDIR/_lib/toolchain-${TERMUX_ARCH}-ndk${TERMUX_NDK_VERSION}-api${TERMUX_API_LEVEL}"
 	# Bump the below version if a change is made in toolchain setup to ensure
 	# that everyone gets an updated toolchain:
-	TERMUX_STANDALONE_TOOLCHAIN+="-v16"
+	TERMUX_STANDALONE_TOOLCHAIN+="-v17"
 
 	export TERMUX_TAR="tar"
 	export TERMUX_TOUCH="touch"
@@ -564,8 +564,9 @@ termux_step_setup_toolchain() {
 		# ifaddrs.h: Added in android-24 unified headers, use a inline implementation for now.
 		cp "$TERMUX_SCRIPTDIR"/ndk_patches/{elf.h,sysexits.h,ifaddrs.h} $_TERMUX_TOOLCHAIN_TMPDIR/sysroot/usr/include
 
-		# Remove <sys/shm.h> from the NDK in favour of that from the libandroid-shmem:
-		rm $_TERMUX_TOOLCHAIN_TMPDIR/sysroot/usr/include/sys/shm.h
+		# Remove <sys/shm.h> from the NDK in favour of that from the libandroid-shmem.
+		# Also remove <sys/sem.h> as it doesn't work for non-root.
+		rm $_TERMUX_TOOLCHAIN_TMPDIR/sysroot/usr/include/sys/{shm.h,sem.h}
 
 		local _LIBDIR=usr/lib
 		if [ $TERMUX_ARCH = x86_64 ]; then _LIBDIR+=64; fi

disabled-packages/postgresql/build.sh

@@ -15,8 +15,5 @@ USE_UNNAMED_POSIX_SEMAPHORES=1
 TERMUX_PKG_EXTRA_MAKE_ARGS=" -s"
 
 termux_step_pre_configure () {
-	# to use shmem and sem stubs
-	CFLAGS+=" -DTERMUX_SEMOPS_STUBS=1"
 	LDFLAGS+=" -llog"
 }
-

ndk_patches/sys-sem.h.patch

@@ -1,17 +0,0 @@
---- /home/vishal/Android/Sdk/ndk-bundle/platforms/android-21/arch-arm/usr/include/sys/sem.h	2016-10-12 15:11:58.000000000 +0530
-+++ ./usr/include/sys/sem.h	2017-01-24 08:23:25.150726158 +0530
-@@ -31,4 +31,14 @@
- 
- #include <linux/sem.h>
- 
-+#ifdef TERMUX_SEMOPS_STUBS
-+
-+#include <sys/syscall.h>
-+
-+#define semop(semid, sops, nsops)  syscall(__NR_semop, semid, sops, nsops)
-+#define semget(key, nsems, semflg) syscall(__NR_semget, key, nsems, semflg)
-+#define semctl(semid, semnum, cmd, ...) syscall(__NR_semctl, semid, semnum, cmd, __VA_ARGS__)
-+
-+#endif /* TERMUX_SEMOPS_STUBS */
-+
- #endif /* _SYS_SEM_H_ */