ksh: ksh fails to compile with tcc

This bug was reported to me by Chase (one of the CDE contributers) via email:

Secondly, I was wondering if you maybe had any insight into why ksh fails to compile with tcc on linux. First, when running CC=tcc ./bin/package make it says it doesn’t like the preprocessor macro #define onexit on_exit in src/lib/libast/comp/atexit.c. When that is fixed (I made an ugly fix by substituting the underscore for a preprocessor macro UNDERSCORE and tcc’s cpp seemed to like that), iffe fails saying that tcc -c doesn’t accept libraries. Since it is only a compiler check testing if int i=1 compiles, I simply took out the -lm the Mamfile was asking for. The last problem is the one that stumps me, pty fails after this and give no helpful debugging output.

I’ve attempted to fix this bug in the patch below, with limited success. It only fixes the compile on Linux and requires a relatively recent version of tcc to build (tcc commit dd60b20c or later). Even with the patch below tcc fails to compile ksh on FreeBSD and it breaks pty on illumos:

diff --git a/src/cmd/INIT/iffe.sh b/src/cmd/INIT/iffe.sh
index 9c0426e5..3647bc43 100644
--- a/src/cmd/INIT/iffe.sh
+++ b/src/cmd/INIT/iffe.sh
@@ -31,10 +31,22 @@ AIX)	unset LIBPATH ;;
 esac
 
 command=iffe
-version=2021-02-03 # update in USAGE too #
+version=2021-03-19 # update in USAGE too #
 
 compile() # $cc ...
 {
+	# tcc can't combine -l* and -c
+	if echo "$@" | grep ' -c' | grep -q ' -l'
+	then
+		for arg
+		do	shift
+			case $arg in
+			-l*) : ;;
+			*) set -- "$@" "$arg"
+			esac
+		done
+	fi
+
 	"$@" 2>$tmp.err
 	_compile_status=$?
 	if	test -s $tmp.err
@@ -753,7 +765,7 @@ set=
 case `(getopts '[-][123:xyz]' opt --xyz; echo 0$opt) 2>/dev/null` in
 0123)	USAGE=$'
 [-?
-@(#)$Id: iffe (ksh 93u+m) 2021-02-03 $
+@(#)$Id: iffe (ksh 93u+m) 2021-03-19 $
 ]
 [-author?Glenn Fowler <gsf@research.att.com>]
 [-author?Phong Vo <kpv@research.att.com>]
diff --git a/src/lib/libast/features/lib b/src/lib/libast/features/lib
index 5a9a67b2..de9410b1 100644
--- a/src/lib/libast/features/lib
+++ b/src/lib/libast/features/lib
@@ -28,7 +28,7 @@ lib	getopt,getsubopt,getopt_long,getopt_long_only
 lib	glob,index,iswblank,iswctype,killpg,link,localeconv,madvise
 lib	mbtowc,mbrtowc,memalign,memchr,memcpy,memdup,memmove,memset
 lib	mkdir,mkfifo,mktemp,mktime
-lib	mount,on_exit,onexit,opendir,pathconf
+lib	mount,onexit,opendir,pathconf
 lib	readlink,remove,rename,rewinddir,rindex,rmdir,setlocale
 lib	setpgid,setpgrp,setpgrp2,setreuid,setsid,setuid,sigaction
 lib	sigprocmask,sigsetmask,sigunblock,sigvec,socketpair
@@ -56,6 +56,21 @@ sys	socket,stream,systeminfo,universe,vfork
 typ	ino64_t,off64_t
 typ	struct.dirent64 dirent.h
 
+tst note{ on_exit works and accepts one argument }end output{
+	#include <stdlib.h>
+
+	static void success(void)
+	{
+		printf("#define _lib_on_exit\t1\n");
+	}
+
+	int main(void)
+	{
+		on_exit(success);
+		exit(0);
+	}
+}end
+
 tst	tst_errno note{ errno can be assigned }end link{
 	_BEGIN_EXTERNS_
 	#define error		______error