From 62b347a1b0767070be1e54884da2b0f63fe36714 Mon Sep 17 00:00:00 2001
From: tg <tg@mirbsd.org>
Date: Sun, 4 Mar 2007 00:13:17 +0000
Subject: [PATCH] merge the const branch +- a few

---
 Makefile  |   3 +-
 edit.c    |   5 +-
 eval.c    |  78 +++++++++++++----------
 exec.c    | 111 +++++++++++++++++---------------
 funcs.c   | 185 +++++++++++++++++++++++++++++-------------------------
 histrap.c |  18 +++---
 main.c    |  27 ++++----
 misc.c    |  14 ++---
 sh.h      | 151 ++++++++++++++++++++++++++------------------
 syn.c     |  24 +++----
 tree.c    |  36 +++++------
 var.c     |   6 +-
 12 files changed, 358 insertions(+), 300 deletions(-)

diff --git a/Makefile b/Makefile
index e7c30f1..e3edff4 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-# $MirOS: src/bin/mksh/Makefile,v 1.32 2007/03/03 21:48:33 tg Exp $
+# $MirOS: src/bin/mksh/Makefile,v 1.33 2007/03/04 00:13:14 tg Exp $
 
 .include <bsd.own.mk>
 
@@ -22,7 +22,6 @@ CPPFLAGS+=	-DMKSH_ASSUME_UTF8 \
 		-DHAVE_MULTI_IDSTRING=1 -DHAVE_PERSISTENT_HISTORY=1
 COPTS+=		-std=gnu99 -Wall
 .endif
-CDIAGFLAGS+=	-Wno-cast-qual
 
 LINKS+=		${BINDIR}/${PROG} ${BINDIR}/sh
 MLINKS+=	${PROG}.1 sh.1
diff --git a/edit.c b/edit.c
index f09bb3d..307ef79 100644
--- a/edit.c
+++ b/edit.c
@@ -5,7 +5,7 @@
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/edit.c,v 1.82 2007/02/16 17:46:42 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/edit.c,v 1.83 2007/03/04 00:13:14 tg Exp $");
 
 /* tty driver characters we are interested in */
 typedef struct {
@@ -602,8 +602,7 @@ x_free_words(int nwords, char **words)
 	int i;
 
 	for (i = 0; i < nwords; i++)
-		if (words[i])
-			afree(words[i], ATEMP);
+		afreechk(words[i])
 	afree(words, ATEMP);
 }
 
diff --git a/eval.c b/eval.c
index 3bce92f..c1e5848 100644
--- a/eval.c
+++ b/eval.c
@@ -2,7 +2,7 @@
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/eval.c,v 1.22 2007/01/17 18:01:51 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/eval.c,v 1.23 2007/03/04 00:13:15 tg Exp $");
 
 #ifdef MKSH_SMALL
 #define MKSH_NOPWNAM
@@ -40,12 +40,12 @@ typedef struct Expand {
 #define IFS_WS		1	/* have seen IFS white-space */
 #define IFS_NWS		2	/* have seen IFS non-white-space */
 
-static int varsub(Expand *, char *, char *, int *, int *);
-static int comsub(Expand *, char *);
+static int varsub(Expand *, const char *, const char *, int *, int *);
+static int comsub(Expand *, const char *);
 static char *trimsub(char *, char *, int);
 static void glob(char *, XPtrV *, int);
 static void globit(XString *, char **, char *, XPtrV *, int);
-static char *maybe_expand_tilde(char *, XString *, char **, int);
+static const char *maybe_expand_tilde(const char *, XString *, char **, int);
 static char *tilde(char *);
 #ifndef MKSH_NOPWNAM
 static char *homedir(char *);
@@ -73,12 +73,16 @@ substitute(const char *cp, int f)
  * expand arg-list
  */
 char **
-eval(char **ap, int f)
+eval(const char **ap, int f)
 {
 	XPtrV w;
 
-	if (*ap == NULL)
-		return ap;
+	if (*ap == NULL) {
+		union mksh_ccphack vap;
+
+		vap.ro = ap;
+		return (vap.rw);
+	}
 	XPinit(w, 32);
 	XPput(w, NULL);		/* space for shell name */
 	while (*ap != NULL)
@@ -91,15 +95,16 @@ eval(char **ap, int f)
  * expand string
  */
 char *
-evalstr(char *cp, int f)
+evalstr(const char *cp, int f)
 {
 	XPtrV w;
+	char *dp;
 
 	XPinit(w, 1);
 	expand(cp, &w, f);
-	cp = (XPsize(w) == 0) ? null : (char*) *XPptrv(w);
+	dp = (XPsize(w) == 0) ? null : (char*) *XPptrv(w);
 	XPfree(w);
-	return cp;
+	return (dp);
 }
 
 /*
@@ -107,25 +112,26 @@ evalstr(char *cp, int f)
  * used from iosetup to expand redirection files
  */
 char *
-evalonestr(char *cp, int f)
+evalonestr(const char *cp, int f)
 {
 	XPtrV w;
+	char *rv;
 
 	XPinit(w, 1);
 	expand(cp, &w, f);
 	switch (XPsize(w)) {
 	case 0:
-		cp = null;
+		rv = null;
 		break;
 	case 1:
-		cp = (char*) *XPptrv(w);
+		rv = (char *) *XPptrv(w);
 		break;
 	default:
-		cp = evalstr(cp, f&~DOGLOB);
+		rv = evalstr(cp, f&~DOGLOB);
 		break;
 	}
 	XPfree(w);
-	return cp;
+	return (rv);
 }
 
 /* for nested substitution: ${var:=$var2} */
@@ -140,7 +146,7 @@ typedef struct SubType {
 } SubType;
 
 void
-expand(char *cp,	/* input word */
+expand(const char *cp,	/* input word */
     XPtrV *wp,		/* output words */
     int f)		/* DO* flags */
 {
@@ -148,7 +154,8 @@ expand(char *cp,	/* input word */
 	int type;		/* expansion type */
 	int quote = 0;		/* quoted */
 	XString ds;		/* destination string */
-	char *dp, *sp;		/* dest., source */
+	char *dp;		/* destination */
+	const char *sp;		/* source */
 	int fdo, word;		/* second pass flags; have word */
 	int doblank;		/* field splitting of parameter/command subst */
 	Expand x = {		/* expansion variables */
@@ -262,26 +269,25 @@ expand(char *cp,	/* input word */
 			   * This is where all syntax checking gets done...
 			   */
 			    {
-				char *varname = ++sp; /* skip the { or x (}) */
+				const char *varname = ++sp; /* skip the { or x (}) */
 				int stype;
 				int slen = 0;
 
 				sp = strchr(sp, '\0') + 1; /* skip variable */
 				type = varsub(&x, varname, sp, &stype, &slen);
 				if (type < 0) {
-					char endc;
-					char *str, *end;
+					char *beg, *end, *str;
 
 					sp = varname - 2; /* restore sp */
-					end = sp + (wdscan(sp, CSUBST) - sp);
+					end = (beg = str_save(sp, ATEMP)) +
+					    (wdscan(sp, CSUBST) - sp);
 					/* ({) the } or x is already skipped */
-					endc = *end;
 					*end = EOS;
-					str = snptreef(NULL, 64, "%S", sp);
-					*end = endc;
+					str = snptreef(NULL, 64, "%S", beg);
+					afree(beg, ATEMP);
 					errorf("%s: bad substitution", str);
 				}
-				if (f&DOBLANK)
+				if (f & DOBLANK)
 					doblank++;
 				tilde_ok = 0;
 				if (type == XBASE) {	/* expand? */
@@ -639,7 +645,8 @@ expand(char *cp,	/* input word */
 					if (type == XBASE &&
 					    (f & (DOTILDE|DOASNTILDE)) &&
 					    (tilde_ok & 2)) {
-						char *p, *dp_x;
+						const char *p;
+						char *dp_x;
 
 						dp_x = dp;
 						p = maybe_expand_tilde(sp,
@@ -676,7 +683,7 @@ expand(char *cp,	/* input word */
  * Prepare to generate the string returned by ${} substitution.
  */
 static int
-varsub(Expand *xp, char *sp, char *word,
+varsub(Expand *xp, const char *sp, const char *word,
     int *stypep,	/* becomes qualifier type */
     int *slenp)		/* " " len (=, :=, etc.) valid iff *stypep != 0 */
 {
@@ -684,7 +691,7 @@ varsub(Expand *xp, char *sp, char *word,
 	int state;	/* next state: XBASE, XARG, XSUB, XNULLSUB */
 	int stype;	/* substitution type */
 	int slen;
-	char *p;
+	const char *p;
 	struct tbl *vp;
 
 	if (sp[0] == '\0')	/* Bad variable name */
@@ -701,7 +708,8 @@ varsub(Expand *xp, char *sp, char *word,
 			return -1;
 		sp++;
 		/* Check for size of array */
-		if ((p=strchr(sp,'[')) && (p[1]=='*'||p[1]=='@') && p[2]==']') {
+		if ((p = cstrchr(sp, '[')) && (p[1] == '*' || p[1] == '@') &&
+		    p[2] == ']') {
 			int n = 0;
 			int max = 0;
 
@@ -772,7 +780,8 @@ varsub(Expand *xp, char *sp, char *word,
 			state = XARG;
 		}
 	} else {
-		if ((p=strchr(sp,'[')) && (p[1]=='*'||p[1]=='@') && p[2]==']') {
+		if ((p = cstrchr(sp, '[')) && (p[1] == '*' || p[1] == '@') &&
+		    p[2] == ']') {
 			XPtrV wv;
 
 			switch (stype & 0x7f) {
@@ -827,7 +836,7 @@ varsub(Expand *xp, char *sp, char *word,
  * Run the command in $(...) and read its output.
  */
 static int
-comsub(Expand *xp, char *cp)
+comsub(Expand *xp, const char *cp)
 {
 	Source *s, *sold;
 	struct op *t;
@@ -1120,12 +1129,13 @@ debunk(char *dp, const char *sp, size_t dlen)
  * puts the expanded version in *dcp,dp and returns a pointer in p just
  * past the name, otherwise returns 0.
  */
-static char *
-maybe_expand_tilde(char *p, XString *dsp, char **dpp, int isassign)
+static const char *
+maybe_expand_tilde(const char *p, XString *dsp, char **dpp, int isassign)
 {
 	XString ts;
 	char *dp = *dpp;
-	char *tp, *r;
+	char *tp;
+	const char *r;
 
 	Xinit(ts, tp, 16, ATEMP);
 	/* : only for DOASNTILDE form */
diff --git a/exec.c b/exec.c
index abab4e1..a2a6372 100644
--- a/exec.c
+++ b/exec.c
@@ -2,22 +2,20 @@
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/exec.c,v 1.24 2007/01/17 22:51:46 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/exec.c,v 1.25 2007/03/04 00:13:15 tg Exp $");
 
-static int	comexec(struct op *, struct tbl *volatile, char **,
-		    int volatile);
-static void	scriptexec(struct op *, char **)
+static int comexec(struct op *, struct tbl *volatile, const char **,
+    int volatile);
+static void scriptexec(struct op *, const char **)
     __attribute__((noreturn));
-static int	call_builtin(struct tbl *, char **);
-static int	iosetup(struct ioword *, struct tbl *);
-static int	herein(const char *, int);
-static char	*do_selectargs(char **, bool);
-static int	dbteste_isa(Test_env *, Test_meta);
+static int call_builtin(struct tbl *, const char **);
+static int iosetup(struct ioword *, struct tbl *);
+static int herein(const char *, int);
+static const char *do_selectargs(const char **, bool);
+static int dbteste_isa(Test_env *, Test_meta);
 static const char *dbteste_getopnd(Test_env *, Test_op, int);
-static int	dbteste_eval(Test_env *, Test_op, const char *, const char *,
-		    int);
-static void	dbteste_error(Test_env *, int, const char *);
-
+static int dbteste_eval(Test_env *, Test_op, const char *, const char *, int);
+static void dbteste_error(Test_env *, int, const char *);
 
 /*
  * execute command tree
@@ -29,8 +27,9 @@ execute(struct op *volatile t,
 	int i;
 	volatile int rv = 0;
 	int pv[2];
-	char ** volatile ap;
-	char *s, *cp;
+	const char ** volatile ap;
+	char ** volatile up;
+	const char *s, *cp;
 	struct ioword **iowp;
 	struct tbl *tp = NULL;
 
@@ -63,10 +62,11 @@ execute(struct op *volatile t,
 		/* POSIX says expand command words first, then redirections,
 		 * and assignments last..
 		 */
-		ap = eval(t->args, t->u.evalflags | DOBLANK | DOGLOB | DOTILDE);
+		up = eval(t->args, t->u.evalflags | DOBLANK | DOGLOB | DOTILDE);
 		if (flags & XTIME)
 			/* Allow option parsing (bizarre, but POSIX) */
-			timex_hook(t, &ap);
+			timex_hook(t, &up);
+		ap = (const char **)up;
 		if (Flag(FXTRACE) && ap[0]) {
 			shf_fprintf(shl_out, "%s",
 				substitute(str_val(global("PS4")), 0));
@@ -104,7 +104,7 @@ execute(struct op *volatile t,
 
 	switch (t->type) {
 	case TCOM:
-		rv = comexec(t, tp, ap, flags);
+		rv = comexec(t, tp, (const char **)ap, flags);
 		break;
 
 	case TPAREN:
@@ -245,8 +245,9 @@ execute(struct op *volatile t,
 	case TSELECT:
 	    {
 		volatile bool is_first = true;
-		ap = (t->vars != NULL) ? eval(t->vars, DOBLANK|DOGLOB|DOTILDE) :
-		    e->loc->argv + 1;
+		ap = (t->vars == NULL) ? e->loc->argv + 1 :
+		    (const char **)eval((const char **)t->vars,
+		    DOBLANK | DOGLOB | DOTILDE);
 		e->type = E_LOOP;
 		while (1) {
 			i = sigsetjmp(e->jbuf, 0);
@@ -314,7 +315,7 @@ execute(struct op *volatile t,
 	case TCASE:
 		cp = evalstr(t->str, DOTILDE);
 		for (t = t->left; t != NULL && t->type == TPAT; t = t->right)
-		    for (ap = t->vars; *ap; ap++)
+		    for (ap = (const char **)t->vars; *ap; ap++)
 			if ((s = evalstr(*ap, DOTILDE|DOPAT)) &&
 			    gmatchx(cp, s, false))
 				goto Found;
@@ -340,12 +341,17 @@ execute(struct op *volatile t,
 
 	case TEXEC:		/* an eval'd TCOM */
 		s = t->args[0];
-		ap = makenv();
+		up = makenv();
 		restoresigs();
 		cleanup_proc_env();
-		execve(t->str, t->args, ap);
+		{
+			union mksh_ccphack cargs;
+
+			cargs.ro = t->args;
+			execve(t->str, cargs.rw, up);
+		}
 		if (errno == ENOEXEC)
-			scriptexec(t, ap);
+			scriptexec(t, (const char **)up);
 		else
 			errorf("%s: %s", s, strerror(errno));
 	}
@@ -368,12 +374,13 @@ execute(struct op *volatile t,
  */
 
 static int
-comexec(struct op *t, struct tbl *volatile tp, char **ap, volatile int flags)
+comexec(struct op *t, struct tbl *volatile tp, const char **ap,
+    volatile int flags)
 {
 	int i;
 	volatile int rv = 0;
-	char *cp;
-	char **lastp;
+	const char *cp;
+	const char **lastp;
 	static struct op texec; /* Must be static (XXX but why?) */
 	int type_flags;
 	int keepasn_ok;
@@ -503,14 +510,14 @@ comexec(struct op *t, struct tbl *volatile tp, char **ap, volatile int flags)
 
 	switch (tp->type) {
 	case CSHELL:			/* shell built-in */
-		rv = call_builtin(tp, ap);
+		rv = call_builtin(tp, (const char **)ap);
 		break;
 
 	case CFUNC:			/* function call */
 	    {
 		volatile int old_xflag;
 		volatile Tflag old_inuse;
-		char *volatile old_kshname;
+		const char *volatile old_kshname;
 
 		if (!(tp->flag & ISSET)) {
 			struct tbl *ftp;
@@ -555,7 +562,7 @@ comexec(struct op *t, struct tbl *volatile tp, char **ap, volatile int flags)
 		if (tp->flag & FKSH)
 			kshname = ap[0];
 		else
-			ap[0] = (char *) kshname;
+			ap[0] = kshname;
 		e->loc->argv = ap;
 		for (i = 0; *ap++ != NULL; i++)
 			;
@@ -664,35 +671,37 @@ comexec(struct op *t, struct tbl *volatile tp, char **ap, volatile int flags)
 }
 
 static void
-scriptexec(struct op *tp, char **ap)
+scriptexec(struct op *tp, const char **ap)
 {
-	static char execshell[] = "/bin/sh";
 	const char *sh;
+	union mksh_ccphack args, cap;
 
 	sh = str_val(global("EXECSHELL"));
 	if (sh && *sh)
 		sh = search(sh, path, X_OK, NULL);
 	if (!sh || !*sh)
-		sh = execshell;
+		sh = "/bin/sh";
 
 	*tp->args-- = tp->str;
-	*tp->args = str_save(sh, ATEMP);
+	args.ro = tp->args;
+	*args.ro = sh;
 
-	execve(tp->args[0], tp->args, ap);
+	cap.ro = ap;
+	execve(args.rw[0], args.rw, cap.rw);
 
 	/* report both the program that was run and the bogus shell */
 	errorf("%s: %s: %s", tp->str, sh, strerror(errno));
 }
 
 int
-shcomexec(char **wp)
+shcomexec(const char **wp)
 {
 	struct tbl *tp;
 
 	tp = ktsearch(&builtins, *wp, hash(*wp));
 	if (tp == NULL)
 		internal_errorf(1, "shcomexec: %s", *wp);
-	return call_builtin(tp, wp);
+	return (call_builtin(tp, wp));
 }
 
 /*
@@ -768,7 +777,7 @@ define(const char *name, struct op *t)
  * add builtin
  */
 void
-builtin(const char *name, int (*func) (char **))
+builtin(const char *name, int (*func) (const char **))
 {
 	struct tbl *tp;
 	Tflag flag;
@@ -970,7 +979,7 @@ search(const char *name, const char *lpath,
 }
 
 static int
-call_builtin(struct tbl *tp, char **wp)
+call_builtin(struct tbl *tp, const char **wp)
 {
 	int rv;
 
@@ -1193,13 +1202,11 @@ herein(const char *content, int sub)
  *	ksh special - the select command processing section
  *	print the args in column form - assuming that we can
  */
-static char *
-do_selectargs(char **ap, bool print_menu)
+static const char *
+do_selectargs(const char **ap, bool print_menu)
 {
-	static char read_args0[] = "read",
-	    read_args1[] = "-r", read_args2[] = "REPLY",
-	    *read_args[] = {
-		read_args0, read_args1, read_args2, NULL
+	static const char *read_args[] = {
+		"read", "-r", "REPLY", NULL
 	};
 	char *s;
 	int i, argct;
@@ -1227,9 +1234,9 @@ do_selectargs(char **ap, bool print_menu)
 }
 
 struct select_menu_info {
-	char	*const *args;
-	int	arg_width;
-	int	num_width;
+	const char *const *args;
+	int arg_width;
+	int num_width;
 };
 
 static char *select_fmt_entry(const void *, int, char *, int);
@@ -1250,10 +1257,10 @@ select_fmt_entry(const void *arg, int i, char *buf, int buflen)
  *	print a select style menu
  */
 int
-pr_menu(char *const *ap)
+pr_menu(const char *const *ap)
 {
 	struct select_menu_info smi;
-	char *const *pp;
+	const char *const *pp;
 	int nwidth, dwidth;
 	int i, n;
 
@@ -1331,7 +1338,7 @@ dbteste_isa(Test_env *te, Test_meta meta)
 {
 	int ret = 0;
 	int uqword;
-	char *p;
+	const char *p;
 
 	if (!*te->pos.wp)
 		return meta == TM_END;
@@ -1367,7 +1374,7 @@ dbteste_isa(Test_env *te, Test_meta meta)
 static const char *
 dbteste_getopnd(Test_env *te, Test_op op, int do_eval)
 {
-	char *s = *te->pos.wp;
+	const char *s = *te->pos.wp;
 
 	if (!s)
 		return NULL;
diff --git a/funcs.c b/funcs.c
index 30b0c37..7b79960 100644
--- a/funcs.c
+++ b/funcs.c
@@ -5,10 +5,10 @@
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/funcs.c,v 1.46 2007/01/26 18:37:26 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/funcs.c,v 1.47 2007/03/04 00:13:15 tg Exp $");
 
 int
-c_cd(char **wp)
+c_cd(const char **wp)
 {
 	int optc;
 	int physical = Flag(FPHYSICAL);
@@ -21,6 +21,7 @@ c_cd(char **wp)
 	char *dir, *try, *pwd;
 	int phys_path;
 	char *cdpath;
+	bool dir_ = false;
 
 	while ((optc = ksh_getopt(wp, &builtin_opt, "LP")) != -1)
 		switch (optc) {
@@ -51,15 +52,17 @@ c_cd(char **wp)
 		}
 	} else if (!wp[1]) {
 		/* One argument: - or dir */
-		dir = wp[0];
+		dir = str_save(wp[0], ATEMP);
 		if (strcmp(dir, "-") == 0) {
+			afree(dir, ATEMP);
 			dir = str_val(oldpwd_s);
 			if (dir == null) {
 				bi_errorf("no OLDPWD");
 				return 1;
 			}
 			printpath++;
-		}
+		} else
+			dir_ = true;
 	} else if (!wp[2]) {
 		/* Two arguments - substitute arg1 in PWD for arg2 */
 		int ilen, olen, nlen, elen;
@@ -83,6 +86,7 @@ c_cd(char **wp)
 		nlen = strlen(wp[1]);
 		elen = strlen(current_wd + ilen + olen) + 1;
 		dir = alloc(ilen + nlen + elen, ATEMP);
+		dir_ = true;
 		memcpy(dir, current_wd, ilen);
 		memcpy(dir + ilen, wp[1], nlen);
 		memcpy(dir + ilen + nlen, current_wd + ilen + olen, elen);
@@ -114,6 +118,7 @@ c_cd(char **wp)
 			bi_errorf("%s: bad directory", dir);
 		else
 			bi_errorf("%s - %s", try, strerror(errno));
+		afreechv(dir_, dir);
 		return 1;
 	}
 
@@ -147,11 +152,12 @@ c_cd(char **wp)
 	if (printpath || cdnode)
 		shprintf("%s\n", pwd);
 
+	afreechv(dir_, dir);
 	return 0;
 }
 
 int
-c_pwd(char **wp)
+c_pwd(const char **wp)
 {
 	int optc;
 	int physical = Flag(FPHYSICAL);
@@ -187,7 +193,7 @@ c_pwd(char **wp)
 }
 
 int
-c_print(char **wp)
+c_print(const char **wp)
 {
 #define PO_NL		BIT(0)	/* print newline */
 #define PO_EXPAND	BIT(1)	/* expand backslash sequences */
@@ -196,7 +202,7 @@ c_print(char **wp)
 #define PO_COPROC	BIT(4)	/* printing to coprocess: block SIGPIPE */
 	int fd = 1;
 	int flags = PO_EXPAND|PO_NL;
-	char *s;
+	const char *s;
 	const char *emsg;
 	XString xs;
 	char *xp;
@@ -375,10 +381,10 @@ c_print(char **wp)
 }
 
 int
-c_whence(char **wp)
+c_whence(const char **wp)
 {
 	struct tbl *tp;
-	char *id;
+	const char *id;
 	int pflag = 0, vflag = 0, Vflag = 0;
 	int ret = 0;
 	int optc;
@@ -495,7 +501,7 @@ c_whence(char **wp)
 
 /* Deal with command -vV - command -p dealt with in comexec() */
 int
-c_command(char **wp)
+c_command(const char **wp)
 {
 	/* Let c_whence do the work.  Note that c_command() must be
 	 * a distinct function from c_whence() (tested in comexec()).
@@ -505,14 +511,14 @@ c_command(char **wp)
 
 /* typeset, export, and readonly */
 int
-c_typeset(char **wp)
+c_typeset(const char **wp)
 {
 	struct block *l = e->loc;
 	struct tbl *vp, **p;
 	Tflag fset = 0, fclr = 0;
 	int thing = 0, func = 0, localv = 0;
 	const char *opts = "L#R#UZ#fi#lprtux";	/* see comment below */
-	char *fieldstr, *basestr;
+	const char *fieldstr, *basestr;
 	int field, base;
 	int optc;
 	Tflag flag;
@@ -802,7 +808,7 @@ c_typeset(char **wp)
 }
 
 int
-c_alias(char **wp)
+c_alias(const char **wp)
 {
 	struct table *t = &aliases;
 	int rv = 0, rflag = 0, tflag, Uflag = 0, pflag = 0;
@@ -856,8 +862,9 @@ c_alias(char **wp)
 
 	/* "hash -r" means reset all the tracked aliases.. */
 	if (rflag) {
-		static char args0[] = "unalias", args1[] = "-ta",
-		    *args[] = { args0, args1, NULL };
+		static const char *args[] = {
+			"unalias", "-ta", NULL
+		};
 
 		if (!tflag || *wp) {
 			shprintf("alias: -r flag can only be used with -t"
@@ -885,14 +892,15 @@ c_alias(char **wp)
 	}
 
 	for (; *wp != NULL; wp++) {
-		char *alias = *wp;
-		char *val = strchr(alias, '=');
+		const char *alias = *wp;
+		char *xalias = NULL;
+		const char *val;
 		const char *newval;
 		struct tbl *ap;
 		int h;
 
-		if (val)
-			alias = str_nsave(alias, val++ - alias, ATEMP);
+		if ((val = cstrchr(alias, '=')))
+			alias = xalias = str_nsave(alias, val++ - alias, ATEMP);
 		h = hash(alias);
 		if (val == NULL && !tflag && !xflag) {
 			ap = ktsearch(t, alias, h);
@@ -933,15 +941,14 @@ c_alias(char **wp)
 			ap->flag &= ~xflag;
 		else
 			ap->flag |= xflag;
-		if (val)
-			afree(alias, ATEMP);
+		afreechk(xalias);
 	}
 
 	return rv;
 }
 
 int
-c_unalias(char **wp)
+c_unalias(const char **wp)
 {
 	struct table *t = &aliases;
 	struct tbl *ap;
@@ -997,7 +1004,7 @@ c_unalias(char **wp)
 }
 
 int
-c_let(char **wp)
+c_let(const char **wp)
 {
 	int rv = 1;
 	long val;
@@ -1015,7 +1022,7 @@ c_let(char **wp)
 }
 
 int
-c_jobs(char **wp)
+c_jobs(const char **wp)
 {
 	int optc;
 	int flag = 0;
@@ -1052,7 +1059,7 @@ c_jobs(char **wp)
 }
 
 int
-c_fgbg(char **wp)
+c_fgbg(const char **wp)
 {
 	int bg = strcmp(*wp, "bg") == 0;
 	int rv = 0;
@@ -1094,10 +1101,10 @@ kill_fmt_entry(const void *arg, int i, char *buf, int buflen)
 
 
 int
-c_kill(char **wp)
+c_kill(const char **wp)
 {
 	Trap *t = NULL;
-	char *p;
+	const char *p;
 	int lflag = 0;
 	int i, n, rv, sig;
 
@@ -1207,7 +1214,7 @@ getopts_reset(int val)
 }
 
 int
-c_getopts(char **wp)
+c_getopts(const char **wp)
 {
 	int	argc;
 	const char *opts;
@@ -1304,7 +1311,7 @@ c_getopts(char **wp)
 }
 
 int
-c_bind(char **wp)
+c_bind(const char **wp)
 {
 	int optc, rv = 0, macro = 0, list = 0;
 	char *cp;
@@ -1369,18 +1376,18 @@ static void p_time(struct shf *, int, struct timeval *, int,
 
 /* :, false and true */
 int
-c_label(char **wp)
+c_label(const char **wp)
 {
 	return wp[0][0] == 'f' ? 1 : 0;
 }
 
 int
-c_shift(char **wp)
+c_shift(const char **wp)
 {
 	struct block *l = e->loc;
 	int n;
 	long val;
-	char *arg;
+	const char *arg;
 
 	if (ksh_getopt(wp, &builtin_opt, null) == '?')
 		return 1;
@@ -1406,10 +1413,10 @@ c_shift(char **wp)
 }
 
 int
-c_umask(char **wp)
+c_umask(const char **wp)
 {
 	int i;
-	char *cp;
+	const char *cp;
 	int symbolic = 0;
 	mode_t old_umask;
 	int optc;
@@ -1427,20 +1434,20 @@ c_umask(char **wp)
 		old_umask = umask(0);
 		umask(old_umask);
 		if (symbolic) {
-			char buf[18];
+			char buf[18], *p;
 			int j;
 
 			old_umask = ~old_umask;
-			cp = buf;
+			p = buf;
 			for (i = 0; i < 3; i++) {
-				*cp++ = "ugo"[i];
-				*cp++ = '=';
+				*p++ = "ugo"[i];
+				*p++ = '=';
 				for (j = 0; j < 3; j++)
 					if (old_umask & (1 << (8 - (3*i + j))))
-						*cp++ = "rwx"[j];
-				*cp++ = ',';
+						*p++ = "rwx"[j];
+				*p++ = ',';
 			}
-			cp[-1] = '\0';
+			p[-1] = '\0';
 			shprintf("%s\n", buf);
 		} else
 			shprintf("%#3.3o\n", (unsigned) old_umask);
@@ -1533,11 +1540,11 @@ c_umask(char **wp)
 }
 
 int
-c_dot(char **wp)
+c_dot(const char **wp)
 {
 	const char *file;
-	char *cp;
-	char **argv;
+	const char *cp;
+	const char **argv;
 	int argc;
 	int i;
 	int err;
@@ -1572,7 +1579,7 @@ c_dot(char **wp)
 }
 
 int
-c_wait(char **wp)
+c_wait(const char **wp)
 {
 	int rv = 0;
 	int sig;
@@ -1594,20 +1601,21 @@ c_wait(char **wp)
 }
 
 int
-c_read(char **wp)
+c_read(const char **wp)
 {
 	int c = 0;
 	int expande = 1, historyr = 0;
 	int expanding;
 	int ecode = 0;
-	char *cp;
+	const char *cp;
+	char *ccp;
 	int fd = 0;
 	struct shf *shf;
 	int optc;
 	const char *emsg;
 	XString cs, xs = { NULL, NULL, 0, NULL};
 	struct tbl *vp;
-	char *xp = NULL;
+	char *xp = NULL, *wpalloc = NULL;
 	static char REPLY[] = "REPLY";
 
 	while ((optc = ksh_getopt(wp, &builtin_opt, "prsu,")) != -1)
@@ -1645,8 +1653,10 @@ c_read(char **wp)
 	 */
 	shf = shf_reopen(fd, SHF_RD | SHF_INTERRUPT | can_seek(fd), shl_spare);
 
-	if ((cp = strchr(*wp, '?')) != NULL) {
-		*cp = 0;
+	if ((cp = cstrchr(*wp, '?')) != NULL) {
+		wpalloc = str_save(*wp, ATEMP);
+		wpalloc[cp - *wp] = '\0';
+		*wp = wpalloc;
 		if (isatty(fd)) {
 			/* at&t ksh says it prints prompt on fd if it's open
 			 * for writing and is a tty, but it doesn't do it
@@ -1671,9 +1681,9 @@ c_read(char **wp)
 	if (historyr)
 		Xinit(xs, xp, 128, ATEMP);
 	expanding = 0;
-	Xinit(cs, cp, 128, ATEMP);
+	Xinit(cs, ccp, 128, ATEMP);
 	for (; *wp != NULL; wp++) {
-		for (cp = Xstring(cs, cp); ; ) {
+		for (ccp = Xstring(cs, ccp); ; ) {
 			if (c == '\n' || c == EOF)
 				break;
 			while (1) {
@@ -1700,7 +1710,7 @@ c_read(char **wp)
 				Xcheck(xs, xp);
 				Xput(xs, xp, c);
 			}
-			Xcheck(cs, cp);
+			Xcheck(cs, ccp);
 			if (expanding) {
 				expanding = 0;
 				if (c == '\n') {
@@ -1713,7 +1723,7 @@ c_read(char **wp)
 						pprompt(prompt, 0);
 					}
 				} else if (c != EOF)
-					Xput(cs, cp, c);
+					Xput(cs, ccp, c);
 				continue;
 			}
 			if (expande && c == '\\') {
@@ -1723,31 +1733,33 @@ c_read(char **wp)
 			if (c == '\n' || c == EOF)
 				break;
 			if (ctype(c, C_IFS)) {
-				if (Xlength(cs, cp) == 0 && ctype(c, C_IFSWS))
+				if (Xlength(cs, ccp) == 0 && ctype(c, C_IFSWS))
 					continue;
 				if (wp[1])
 					break;
 			}
-			Xput(cs, cp, c);
+			Xput(cs, ccp, c);
 		}
 		/* strip trailing IFS white space from last variable */
 		if (!wp[1])
-			while (Xlength(cs, cp) && ctype(cp[-1], C_IFS) &&
-			    ctype(cp[-1], C_IFSWS))
-				cp--;
-		Xput(cs, cp, '\0');
+			while (Xlength(cs, ccp) && ctype(ccp[-1], C_IFS) &&
+			    ctype(ccp[-1], C_IFSWS))
+				ccp--;
+		Xput(cs, ccp, '\0');
 		vp = global(*wp);
 		/* Must be done before setting export. */
 		if (vp->flag & RDONLY) {
 			shf_flush(shf);
 			bi_errorf("%s is read only", *wp);
+			afreechk(wpalloc);
 			return 1;
 		}
 		if (Flag(FEXPORT))
 			typeset(*wp, EXPORT, 0, 0, 0);
-		if (!setstr(vp, Xstring(cs, cp), KSH_RETURN_ERROR)) {
-		    shf_flush(shf);
-		    return 1;
+		if (!setstr(vp, Xstring(cs, ccp), KSH_RETURN_ERROR)) {
+			shf_flush(shf);
+			afreechk(wpalloc);
+			return 1;
 		}
 	}
 
@@ -1765,11 +1777,12 @@ c_read(char **wp)
 	if (c == EOF && !ecode)
 		coproc_read_close(fd);
 
+	afreechk(wpalloc);
 	return ecode ? ecode : c == EOF;
 }
 
 int
-c_eval(char **wp)
+c_eval(const char **wp)
 {
 	struct source *s, *saves = source;
 	int savef, rv;
@@ -1814,10 +1827,10 @@ c_eval(char **wp)
 }
 
 int
-c_trap(char **wp)
+c_trap(const char **wp)
 {
 	int i;
-	char *s;
+	const char *s;
 	Trap *p;
 
 	if (ksh_getopt(wp, &builtin_opt, null) == '?')
@@ -1861,11 +1874,11 @@ c_trap(char **wp)
 }
 
 int
-c_exitreturn(char **wp)
+c_exitreturn(const char **wp)
 {
 	int how = LEXIT;
 	int n;
-	char *arg;
+	const char *arg;
 
 	if (ksh_getopt(wp, &builtin_opt, null) == '?')
 		return 1;
@@ -1903,11 +1916,11 @@ c_exitreturn(char **wp)
 }
 
 int
-c_brkcont(char **wp)
+c_brkcont(const char **wp)
 {
 	int n, quit;
 	struct env *ep, *last_ep = NULL;
-	char *arg;
+	const char *arg;
 
 	if (ksh_getopt(wp, &builtin_opt, null) == '?')
 		return 1;
@@ -1956,15 +1969,14 @@ c_brkcont(char **wp)
 }
 
 int
-c_set(char **wp)
+c_set(const char **wp)
 {
 	int argi, setargs;
 	struct block *l = e->loc;
-	char **owp = wp;
+	const char **owp = wp;
 
 	if (wp[1] == NULL) {
-		static char args0[] = "set", args1[] = "-",
-		    *args[] = { args0, args1, NULL };
+		static const char *args [] = { "set", "-", NULL };
 		return c_typeset(args);
 	}
 
@@ -1978,7 +1990,8 @@ c_set(char **wp)
 		while (*++wp != NULL)
 			*wp = str_save(*wp, &l->area);
 		l->argc = wp - owp - 1;
-		l->argv = (char **) alloc(sizeofN(char *, l->argc+2), &l->area);
+		l->argv = (const char **) alloc(sizeofN(char *, l->argc+2),
+		     &l->area);
 		for (wp = l->argv; (*wp++ = *owp++) != NULL; )
 			;
 	}
@@ -1992,9 +2005,9 @@ c_set(char **wp)
 }
 
 int
-c_unset(char **wp)
+c_unset(const char **wp)
 {
-	char *id;
+	const char *id;
 	int optc, unset_var = 1;
 	int ret = 0;
 
@@ -2042,7 +2055,7 @@ p_time(struct shf *shf, int posix, struct timeval *tv, int width,
 }
 
 int
-c_times(char **wp __unused)
+c_times(const char **wp __unused)
 {
 	struct rusage usage;
 
@@ -2147,7 +2160,7 @@ timex_hook(struct op *t, char **volatile *app)
 
 	ksh_getopt_reset(&opt, 0);
 	opt.optind = 0;	/* start at the start */
-	while ((optc = ksh_getopt(wp, &opt, ":p")) != -1)
+	while ((optc = ksh_getopt((const char **)wp, &opt, ":p")) != -1)
 		switch (optc) {
 		case 'p':
 			t->str[0] |= TF_POSIX;
@@ -2172,7 +2185,7 @@ timex_hook(struct op *t, char **volatile *app)
 
 /* exec with no args - args case is taken care of in comexec() */
 int
-c_exec(char **wp __unused)
+c_exec(const char **wp __unused)
 {
 	int i;
 
@@ -2192,11 +2205,11 @@ c_exec(char **wp __unused)
 
 #if !defined(MKSH_SMALL) || defined(MKSH_NEED_MKNOD)
 static int
-c_mknod(char **wp)
+c_mknod(const char **wp)
 {
 	int argc, optc, rv = 0;
 	bool ismkfifo = false;
-	char **argv;
+	const char **argv;
 	void *set = NULL;
 	mode_t mode = 0, oldmode = 0;
 
@@ -2278,7 +2291,7 @@ c_mknod(char **wp)
 
 /* dummy function, special case in comexec() */
 int
-c_builtin(char **wp __unused)
+c_builtin(const char **wp __unused)
 {
 	return 0;
 }
@@ -2401,7 +2414,7 @@ static int	ptest_eval(Test_env *, Test_op, const char *,
 static void	ptest_error(Test_env *, int, const char *);
 
 int
-c_test(char **wp)
+c_test(const char **wp)
 {
 	int argc;
 	int res;
@@ -2432,7 +2445,7 @@ c_test(char **wp)
 	 * our parser does the right thing for the omitted steps.
 	 */
 	if (argc <= 5) {
-		char **owp = wp;
+		const char **owp = wp;
 		int invert = 0;
 		Test_op	op;
 		const char *opnd1, *opnd2;
@@ -2834,7 +2847,7 @@ ptest_error(Test_env *te, int offset, const char *msg)
 #define HARD	0x2
 
 int
-c_ulimit(char **wp)
+c_ulimit(const char **wp)
 {
 	static const struct limits {
 		const char	*name;
diff --git a/histrap.c b/histrap.c
index 4e97322..4f170b1 100644
--- a/histrap.c
+++ b/histrap.c
@@ -3,7 +3,7 @@
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/histrap.c,v 1.43 2007/03/03 21:36:07 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/histrap.c,v 1.44 2007/03/04 00:13:16 tg Exp $");
 
 Trap sigtraps[NSIG + 1];
 static struct sigaction Sigact_ign, Sigact_trap;
@@ -35,14 +35,15 @@ static int	hsize;
 #endif
 
 int
-c_fc(char **wp)
+c_fc(const char **wp)
 {
 	struct shf *shf;
 	struct temp *tf = NULL;
-	char *p, *editor = NULL;
+	const char *p;
+	char *editor = NULL;
 	int gflag = 0, lflag = 0, nflag = 0, sflag = 0, rflag = 0;
 	int optc;
-	char *first = NULL, *last = NULL;
+	const char *first = NULL, *last = NULL;
 	char **hfirst, **hlast, **hp;
 
 	if (!Flag(FTALKING_I)) {
@@ -107,11 +108,10 @@ c_fc(char **wp)
 		}
 
 		/* Check for pattern replacement argument */
-		if (*wp && **wp && (p = strchr(*wp + 1, '='))) {
+		if (*wp && **wp && (p = cstrchr(*wp + 1, '='))) {
 			pat = str_save(*wp, ATEMP);
-			p = pat + (p - *wp);
-			*p++ = '\0';
-			rep = p;
+			rep = pat + (p - *wp);
+			*rep++ = '\0';
 			wp++;
 		}
 		/* Check for search prefix */
@@ -1239,7 +1239,7 @@ restoresigs(void)
 }
 
 void
-settrap(Trap *p, char *s)
+settrap(Trap *p, const char *s)
 {
 	sig_t f;
 
diff --git a/main.c b/main.c
index 6cb4da6..bb17f8c 100644
--- a/main.c
+++ b/main.c
@@ -13,7 +13,7 @@
 #include <locale.h>
 #endif
 
-__RCSID("$MirOS: src/bin/mksh/main.c,v 1.71 2007/03/03 21:36:07 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/main.c,v 1.72 2007/03/04 00:13:16 tg Exp $");
 
 extern char **environ;
 
@@ -60,14 +60,14 @@ static const char *initcoms[] = {
 static int initio_done;
 
 int
-main(int argc, char *argv[])
+main(int argc, const char *argv[])
 {
 	int i;
 	int argi;
 	Source *s;
 	struct block *l;
 	int restricted, errexit;
-	char **wp;
+	const char **wp;
 	struct env env;
 	pid_t ppid;
 	struct tbl *vp;
@@ -82,8 +82,9 @@ main(int argc, char *argv[])
 
 	/* make sure argv[] is sane */
 	if (!*argv) {
-		static char empty_argv0[] = "mksh",
-		    *empty_argv[] = { empty_argv0, NULL };
+		static const char *empty_argv[] = {
+			"mksh", NULL
+		};
 
 		argv = empty_argv;
 		argc = 1;
@@ -180,7 +181,7 @@ main(int argc, char *argv[])
 
 	/* import environment */
 	if (environ != NULL)
-		for (wp = environ; *wp != NULL; wp++)
+		for (wp = (const char **)environ; *wp != NULL; wp++)
 			typeset(*wp, IMPORT | EXPORT, 0, 0, 0);
 
 	kshpid = procpid = getpid();
@@ -219,7 +220,7 @@ main(int argc, char *argv[])
 	setint(global("PPID"), (long)ppid);
 
 	/* execute initialisation statements */
-	for (wp = (char **)initcoms; *wp != NULL; wp++) {
+	for (wp = initcoms; *wp != NULL; wp++) {
 		shcomexec(wp);
 		for (; *wp != NULL; wp++)
 			;
@@ -312,7 +313,7 @@ main(int argc, char *argv[])
 	l = e->loc;
 	l->argv = &argv[argi - 1];
 	l->argc = argc - argi;
-	l->argv[0] = (char *)kshname;
+	l->argv[0] = kshname;
 	getopts_reset(1);
 
 	/* Disable during .profile/ENV reading */
@@ -346,12 +347,12 @@ main(int argc, char *argv[])
 	}
 
 	if (restricted) {
-		static const char *const restr_com[] = {
+		static const char *restr_com[] = {
 			"typeset", "-r", "PATH",
 			"ENV", "SHELL",
 			NULL
 		};
-		shcomexec((char **)restr_com);
+		shcomexec(restr_com);
 		/* After typeset command... */
 		Flag(FRESTRICTED) = 1;
 	}
@@ -369,11 +370,11 @@ main(int argc, char *argv[])
 }
 
 int
-include(const char *name, int argc, char **argv, int intr_ok)
+include(const char *name, int argc, const char **argv, int intr_ok)
 {
 	Source *volatile s = NULL;
 	struct shf *shf;
-	char **volatile old_argv;
+	const char **volatile old_argv;
 	volatile int old_argc;
 	int i;
 
@@ -975,7 +976,7 @@ closepipe(int *pv)
  * a string (the X in 2>&X, read -uX, print -uX) into a file descriptor.
  */
 int
-check_fd(char *name, int mode, const char **emsgp)
+check_fd(const char *name, int mode, const char **emsgp)
 {
 	int fd, fl;
 
diff --git a/misc.c b/misc.c
index 98b6a8c..ac0fa8a 100644
--- a/misc.c
+++ b/misc.c
@@ -6,7 +6,7 @@
 #include <grp.h>
 #endif
 
-__RCSID("$MirOS: src/bin/mksh/misc.c,v 1.50 2007/01/26 18:27:34 tg Exp $\t"
+__RCSID("$MirOS: src/bin/mksh/misc.c,v 1.51 2007/03/04 00:13:16 tg Exp $\t"
 	MKSH_SH_H_ID);
 
 #undef USE_CHVT
@@ -88,9 +88,9 @@ str_save(const char *s, Area *ap)
 
 /* called from XcheckN() to grow buffer */
 char *
-Xcheck_grow_(XString *xsp, char *xp, unsigned more)
+Xcheck_grow_(XString *xsp, const char *xp, unsigned more)
 {
-	char *old_beg = xsp->beg;
+	const char *old_beg = xsp->beg;
 
 	xsp->len += more > xsp->len ? more : xsp->len;
 	xsp->beg = aresize(xsp->beg, xsp->len + 8, xsp->areap);
@@ -268,14 +268,14 @@ change_flag(enum sh_flag f,
  * non-option arguments, -1 if there is an error.
  */
 int
-parse_args(char **argv,
+parse_args(const char **argv,
     int what,			/* OF_CMDLINE or OF_SET */
     int *setargsp)
 {
 	static char cmd_opts[NELEM(options) + 5]; /* o:T:\0 */
 	static char set_opts[NELEM(options) + 6]; /* A:o;s\0 */
 	char *opts;
-	char *array = NULL;
+	const char *array = NULL;
 	Getopt go;
 	int optc, set, sortargs = 0, arrayset = 0;
 	unsigned i;
@@ -808,13 +808,13 @@ ksh_getopt_reset(Getopt *go, int flags)
  *	  in go->info.
  */
 int
-ksh_getopt(char **argv, Getopt *go, const char *optionsp)
+ksh_getopt(const char **argv, Getopt *go, const char *optionsp)
 {
 	char c;
 	char *o;
 
 	if (go->p == 0 || (c = argv[go->optind - 1][go->p]) == '\0') {
-		char *arg = argv[go->optind], flag = arg ? *arg : '\0';
+		const char *arg = argv[go->optind], flag = arg ? *arg : '\0';
 
 		go->p = 1;
 		if (flag == '-' && arg[1] == '-' && arg[2] == '\0') {
diff --git a/sh.h b/sh.h
index 646c882..30f7060 100644
--- a/sh.h
+++ b/sh.h
@@ -8,7 +8,7 @@
 /*	$OpenBSD: c_test.h,v 1.4 2004/12/20 11:34:26 otto Exp $	*/
 /*	$OpenBSD: tty.h,v 1.5 2004/12/20 11:34:26 otto Exp $	*/
 
-#define MKSH_SH_H_ID "$MirOS: src/bin/mksh/sh.h,v 1.113 2007/03/03 21:36:07 tg Exp $"
+#define MKSH_SH_H_ID "$MirOS: src/bin/mksh/sh.h,v 1.114 2007/03/04 00:13:16 tg Exp $"
 #define MKSH_VERSION "R29 2007/02/16"
 
 #if HAVE_SYS_PARAM_H
@@ -220,7 +220,7 @@ typedef int32_t Tflag;
 #define PATH_MAX	1024	/* pathname size */
 #endif
 
-EXTERN	char *kshname;		/* $0 */
+EXTERN	const char *kshname;	/* $0 */
 EXTERN	pid_t kshpid;		/* $$, shell pid */
 EXTERN	pid_t procpid;		/* pid of executing process */
 EXTERN	uid_t ksheuid;		/* effective uid of shell */
@@ -230,6 +230,25 @@ EXTERN	const char *safe_prompt; /* safe prompt if PS1 substitution fails */
 EXTERN	const char initvsn[] I__("KSH_VERSION=@(#)MIRBSD KSH " MKSH_VERSION);
 #define KSH_VERSION	(initvsn + 16)
 
+/*
+ * Evil hack for const correctness due to API brokenness
+ */
+union mksh_cchack {
+	char *rw;
+	const char *ro;
+};
+union mksh_ccphack {
+	char **rw;
+	const char **ro;
+};
+#define cstrchr(s,c) __extension__({	\
+	union mksh_cchack in, out;	\
+					\
+	in.ro = (s);			\
+	out.rw = strchr(in.rw, (c));	\
+	(out.ro);			\
+})
+
 /*
  * Area-based allocation built on malloc/free
  */
@@ -471,7 +490,7 @@ EXTERN int ifs0 I__(' ');	/* for "$*" */
 typedef struct {
 	int		optind;
 	int		uoptind;/* what user sees in $OPTIND */
-	char		*optarg;
+	const char	*optarg;
 	int		flags;	/* see GF_* */
 	int		info;	/* see GI_* */
 	unsigned int	p;	/* 0 or index into argv[optind - 1] */
@@ -498,8 +517,8 @@ EXTERN struct coproc coproc;
 EXTERN sigset_t		sm_default, sm_sigchld;
 
 /* name of called builtin function (used by error functions) */
-EXTERN char	*builtin_argv0;
-EXTERN Tflag	builtin_flag;	/* flags of called builtin (SPEC_BI, etc.) */
+EXTERN const char *builtin_argv0;
+EXTERN Tflag builtin_flag;	/* flags of called builtin (SPEC_BI, etc.) */
 
 /* current working directory, and size of memory allocated for same */
 EXTERN char	*current_wd;
@@ -604,7 +623,7 @@ struct tbl {			/* table item */
 	union {
 		char *s;	/* string */
 		long i;		/* integer */
-		int (*f)(char **);	/* int function */
+		int (*f)(const char **);	/* int function */
 		struct op *t;	/* "function" tree */
 	} val;			/* value */
 	int index;		/* index for an array */
@@ -693,7 +712,7 @@ struct arg_info {
  */
 struct block {
 	Area area;		/* area to allocate things */
-	char **argv;
+	const char **argv;
 	int argc;
 	int flags;		/* see BF_* */
 	struct table vars;	/* local variables */
@@ -726,7 +745,7 @@ EXTERN	struct table homedirs;	/* homedir() cache */
 
 struct builtin {
 	const char *name;
-	int (*func)(char **);
+	int (*func)(const char **);
 };
 
 extern const struct builtin shbuiltins [], kshbuiltins [];
@@ -769,7 +788,7 @@ struct op {
 		short evalflags;	/* TCOM: arg expansion eval() flags */
 		short ksh_func;		/* TFUNC: function x (vs x()) */
 	} u;
-	char **args;			/* arguments to a command */
+	const char **args;		/* arguments to a command */
 	char **vars;			/* variable assignments */
 	struct ioword **ioact;		/* IO actions (eg, < > >>) */
 	struct op *left, *right;	/* descendents */
@@ -937,7 +956,7 @@ typedef char *XStringP;
 #define Xsavepos(xs, xp) ((xp) - (xs).beg)
 #define Xrestpos(xs, xp, n) ((xs).beg + (n))
 
-char *Xcheck_grow_(XString *, char *, unsigned);
+char *Xcheck_grow_(XString *, const char *, unsigned);
 
 /*
  * expandable vector of generic pointers
@@ -982,10 +1001,10 @@ struct source {
 	int	type;		/* input type */
 	const char *start;	/* start of current buffer */
 	union {
-		char **strv;	/* string [] */
-		struct shf *shf; /* shell file */
-		struct tbl *tblp; /* alias (SALIAS) */
-		char *freeme;	/* also for SREREAD */
+		const char **strv; /* string [] */
+		struct shf *shf;   /* shell file */
+		struct tbl *tblp;  /* alias (SALIAS) */
+		char *freeme;	   /* also for SREREAD */
 	} u;
 	char	ugbuf[2];	/* buffer for ungetsc() (SREREAD) and
 				 * alias (SALIAS) */
@@ -1101,6 +1120,14 @@ void afreeall(Area *);
 void *alloc(size_t, Area *);
 void *aresize(void *, size_t, Area *);
 void afree(void *, Area *);
+#define afreechk(s)	do {		\
+	if (s)				\
+		afree(s, ATEMP);	\
+} while (0)
+#define afreechv(v,s)	do {		\
+	if (v)				\
+		afree(s, ATEMP);	\
+} while (0)
 /* edit.c */
 void x_init(void);
 int x_read(char *, size_t);
@@ -1110,63 +1137,63 @@ int utf_widthadj(const char *, const char **);
 #define utf_width(x)	utf_widthadj(x, NULL);
 /* eval.c */
 char *substitute(const char *, int);
-char **eval(char **, int);
-char *evalstr(char *cp, int);
-char *evalonestr(char *cp, int);
+char **eval(const char **, int);
+char *evalstr(const char *cp, int);
+char *evalonestr(const char *cp, int);
 char *debunk(char *, const char *, size_t);
-void expand(char *, XPtrV *, int);
+void expand(const char *, XPtrV *, int);
 int glob_str(char *, XPtrV *, int);
 /* exec.c */
 int execute(struct op * volatile, volatile int);
-int shcomexec(char **);
+int shcomexec(const char **);
 struct tbl *findfunc(const char *, unsigned int, int);
 int define(const char *, struct op *);
-void builtin(const char *, int (*)(char **));
+void builtin(const char *, int (*)(const char **));
 struct tbl *findcom(const char *, int);
 void flushcom(int);
 const char *search(const char *, const char *, int, int *);
 int search_access(const char *, int, int *);
-int pr_menu(char *const *);
+int pr_menu(const char *const *);
 int pr_list(char *const *);
 /* expr.c */
 int evaluate(const char *, long *, int, bool);
 int v_evaluate(struct tbl *, const char *, volatile int, bool);
 /* funcs.c */
-int c_hash(char **);
-int c_cd(char **);
-int c_pwd(char **);
-int c_print(char **);
-int c_whence(char **);
-int c_command(char **);
-int c_typeset(char **);
-int c_alias(char **);
-int c_unalias(char **);
-int c_let(char **);
-int c_jobs(char **);
-int c_fgbg(char **);
-int c_kill(char **);
+int c_hash(const char **);
+int c_cd(const char **);
+int c_pwd(const char **);
+int c_print(const char **);
+int c_whence(const char **);
+int c_command(const char **);
+int c_typeset(const char **);
+int c_alias(const char **);
+int c_unalias(const char **);
+int c_let(const char **);
+int c_jobs(const char **);
+int c_fgbg(const char **);
+int c_kill(const char **);
 void getopts_reset(int);
-int c_getopts(char **);
-int c_bind(char **);
-int c_label(char **);
-int c_shift(char **);
-int c_umask(char **);
-int c_dot(char **);
-int c_wait(char **);
-int c_read(char **);
-int c_eval(char **);
-int c_trap(char **);
-int c_brkcont(char **);
-int c_exitreturn(char **);
-int c_set(char **);
-int c_unset(char **);
-int c_ulimit(char **);
-int c_times(char **);
+int c_getopts(const char **);
+int c_bind(const char **);
+int c_label(const char **);
+int c_shift(const char **);
+int c_umask(const char **);
+int c_dot(const char **);
+int c_wait(const char **);
+int c_read(const char **);
+int c_eval(const char **);
+int c_trap(const char **);
+int c_brkcont(const char **);
+int c_exitreturn(const char **);
+int c_set(const char **);
+int c_unset(const char **);
+int c_ulimit(const char **);
+int c_times(const char **);
 int timex(struct op *, int);
 void timex_hook(struct op *, char ** volatile *);
-int c_exec(char **);
-int c_builtin(char **);
-int c_test(char **);
+int c_exec(const char **);
+int c_builtin(const char **);
+int c_test(const char **);
 /* histrap.c */
 void init_histvec(void);
 void hist_init(Source *);
@@ -1174,7 +1201,7 @@ void hist_init(Source *);
 void hist_finish(void);
 #endif
 void histsave(int, const char *, int);
-int c_fc(char **);
+int c_fc(const char **);
 void sethistsize(int);
 #if HAVE_PERSISTENT_HISTORY
 void sethistfile(const char *);
@@ -1195,7 +1222,7 @@ void runtraps(int intr);
 void runtrap(Trap *);
 void cleartraps(void);
 void restoresigs(void);
-void settrap(Trap *, char *);
+void settrap(Trap *, const char *);
 int block_pipe(void);
 void restore_pipe(int);
 int setsig(Trap *, sig_t, int);
@@ -1225,7 +1252,7 @@ void set_prompt(int, Source *);
 void pprompt(const char *, int);
 int promptlen(const char *);
 /* main.c */
-int include(const char *, int, char **, int);
+int include(const char *, int, const char **, int);
 int command(const char *);
 int shell(Source *volatile, int volatile);
 void unwind(int)
@@ -1255,7 +1282,7 @@ int savefd(int);
 void restfd(int, int);
 void openpipe(int *);
 void closepipe(int *);
-int check_fd(char *, int, const char **);
+int check_fd(const char *, int, const char **);
 void coproc_init(void);
 void coproc_read_close(int);
 void coproc_readw_close(int);
@@ -1283,7 +1310,7 @@ char *str_nsave(const char *, int, Area *);
 int option(const char *);
 char *getoptions(void);
 void change_flag(enum sh_flag, int, int);
-int parse_args(char **, int, int *);
+int parse_args(const char **, int, int *);
 int getn(const char *, int *);
 int bi_getn(const char *, int *);
 int gmatchx(const char *, const char *, int);
@@ -1291,7 +1318,7 @@ int has_globbing(const char *, const char *);
 const unsigned char *pat_scan(const unsigned char *, const unsigned char *, int);
 int xstrcmp(const void *, const void *);
 void ksh_getopt_reset(Getopt *, int);
-int ksh_getopt(char **, Getopt *, const char *);
+int ksh_getopt(const char **, Getopt *, const char *);
 void print_value_quoted(const char *);
 void print_columns(struct shf *, int,
     char *(*)(const void *, int, char *, int),
@@ -1362,7 +1389,7 @@ char **makenv(void);
 void change_random(void);
 int array_ref_len(const char *);
 char *arrayname(const char *);
-void set_array(const char *, int, char **);
+void set_array(const char *, int, const char **);
 
 enum Test_op {
 	TO_NONOP = 0,	/* non-operator */
@@ -1399,10 +1426,10 @@ typedef struct test_env Test_env;
 struct test_env {
 	int flags;		/* TEF_* */
 	union {
-		char **wp;	/* used by ptest_* */
+		const char **wp;/* used by ptest_* */
 		XPtrV *av;	/* used by dbtestp_* */
 	} pos;
-	char **wp_end;		/* used by ptest_* */
+	const char **wp_end;	/* used by ptest_* */
 	int (*isa)(Test_env *, Test_meta);
 	const char *(*getopnd) (Test_env *, Test_op, int);
 	int (*eval)(Test_env *, Test_op, const char *, const char *, int);
diff --git a/syn.c b/syn.c
index 041f669..a8bbdf6 100644
--- a/syn.c
+++ b/syn.c
@@ -2,7 +2,7 @@
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/syn.c,v 1.10 2007/01/17 22:51:47 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/syn.c,v 1.11 2007/03/04 00:13:17 tg Exp $");
 
 struct nesting_state {
 	int	start_token;	/* token than began nesting (eg, FOR) */
@@ -376,7 +376,7 @@ get_command(int cf)
 	}
 
 	if (iopn == 0) {
-		afree((void*) iops, ATEMP);
+		afree((void*)iops, ATEMP);
 		t->ioact = NULL;
 	} else {
 		iops[iopn++] = NULL;
@@ -387,7 +387,7 @@ get_command(int cf)
 
 	if (t->type == TCOM || t->type == TDBRACKET) {
 		XPput(args, NULL);
-		t->args = (char **) XPclose(args);
+		t->args = (const char **)XPclose(args);
 		XPput(vars, NULL);
 		t->vars = (char **) XPclose(vars);
 	} else {
@@ -549,6 +549,7 @@ function_body(char *name,
 	old_func_parse = e->flags & EF_FUNC_PARSE;
 	e->flags |= EF_FUNC_PARSE;
 	if ((t->left = get_command(CONTIN)) == NULL) {
+		char *tv;
 		/*
 		 * Probably something like foo() followed by eof or ;.
 		 * This is accepted by sh and ksh88.
@@ -556,13 +557,13 @@ function_body(char *name,
 		 * be used as input), we pretend there is a colon here.
 		 */
 		t->left = newtp(TCOM);
-		t->left->args = (char **) alloc(sizeof(char *) * 2, ATEMP);
-		t->left->args[0] = alloc(sizeof(char) * 3, ATEMP);
-		t->left->args[0][0] = CHAR;
-		t->left->args[0][1] = ':';
-		t->left->args[0][2] = EOS;
+		t->left->args = (const char **)alloc(sizeof(char *) * 2, ATEMP);
+		t->left->args[0] = tv = alloc(sizeof(char) * 3, ATEMP);
+		tv[0] = CHAR;
+		tv[1] = ':';
+		tv[2] = EOS;
 		t->left->args[1] = NULL;
-		t->left->vars = (char **) alloc(sizeof(char *), ATEMP);
+		t->left->vars = (char **)alloc(sizeof(char *), ATEMP);
 		t->left->vars[0] = NULL;
 		t->left->lineno = 1;
 	}
@@ -739,10 +740,11 @@ newtp(int type)
 {
 	struct op *t;
 
-	t = (struct op *) alloc(sizeof(*t), ATEMP);
+	t = (struct op *)alloc(sizeof(*t), ATEMP);
 	t->type = type;
 	t->u.evalflags = 0;
-	t->args = t->vars = NULL;
+	t->args = NULL;
+	t->vars = NULL;
 	t->ioact = NULL;
 	t->left = t->right = NULL;
 	t->str = NULL;
diff --git a/tree.c b/tree.c
index 0a11d35..dfbf056 100644
--- a/tree.c
+++ b/tree.c
@@ -2,7 +2,7 @@
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/tree.c,v 1.7 2006/11/12 14:58:16 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/tree.c,v 1.8 2007/03/04 00:13:17 tg Exp $");
 
 #define INDENT	4
 
@@ -18,11 +18,10 @@ static void     iofree(struct ioword **, Area *);
 /*
  * print a command tree
  */
-
 static void
 ptree(struct op *t, int indent, struct shf *shf)
 {
-	char **w;
+	const char **w;
 	struct ioword **ioact;
 	struct op *t1;
 
@@ -32,7 +31,7 @@ ptree(struct op *t, int indent, struct shf *shf)
 	switch (t->type) {
 	case TCOM:
 		if (t->vars)
-			for (w = t->vars; *w != NULL; )
+			for (w = (const char **)t->vars; *w != NULL; )
 				fptreef(shf, indent, "%S ", *w++);
 		else
 			fptreef(shf, indent, "#no-vars# ");
@@ -83,7 +82,7 @@ ptree(struct op *t, int indent, struct shf *shf)
 			fptreef(shf, indent, "for %s ", t->str);
 		if (t->vars != NULL) {
 			fptreef(shf, indent, "in ");
-			for (w = t->vars; *w; )
+			for (w = (const char **)t->vars; *w; )
 				fptreef(shf, indent, "%S ", *w++);
 			fptreef(shf, indent, "%;");
 		}
@@ -94,7 +93,7 @@ ptree(struct op *t, int indent, struct shf *shf)
 		fptreef(shf, indent, "case %S in", t->str);
 		for (t1 = t->left; t1 != NULL; t1 = t1->right) {
 			fptreef(shf, indent, "%N(");
-			for (w = t1->vars; *w != NULL; w++)
+			for (w = (const char **)t1->vars; *w != NULL; w++)
 				fptreef(shf, indent, "%S%c", *w,
 				    (w[1] != NULL) ? '|' : ')');
 			fptreef(shf, indent + INDENT, "%;%T%N;;", t1->left);
@@ -240,7 +239,6 @@ pioact(struct shf *shf, int indent, struct ioword *iop)
 /*
  * variants of fputc, fputs for ptreef and snptreef
  */
-
 static void
 tputC(int c, struct shf *shf)
 {
@@ -419,12 +417,12 @@ vfptreef(struct shf *shf, int indent, const char *fmt, va_list va)
 /*
  * copy tree (for function definition)
  */
-
 struct op *
 tcopy(struct op *t, Area *ap)
 {
 	struct op *r;
-	char **tw, **rw;
+	const char **tw;
+	char **rw;
 
 	if (t == NULL)
 		return NULL;
@@ -439,11 +437,11 @@ tcopy(struct op *t, Area *ap)
 	if (t->vars == NULL)
 		r->vars = NULL;
 	else {
-		for (tw = t->vars; *tw++ != NULL; )
+		for (tw = (const char **)t->vars; *tw++ != NULL; )
 			;
 		rw = r->vars = (char **)
-			alloc((tw - t->vars + 1) * sizeof(*tw), ap);
-		for (tw = t->vars; *tw != NULL; )
+		    alloc((tw - (const char **)t->vars + 1) * sizeof(*tw), ap);
+		for (tw = (const char **)t->vars; *tw != NULL; )
 			*rw++ = wdcopy(*tw++, ap);
 		*rw = NULL;
 	}
@@ -453,8 +451,8 @@ tcopy(struct op *t, Area *ap)
 	else {
 		for (tw = t->args; *tw++ != NULL; )
 			;
-		rw = r->args = (char **)
-			alloc((tw - t->args + 1) * sizeof(*tw), ap);
+		r->args = (const char **)(rw = (char **)
+			alloc((tw - t->args + 1) * sizeof(*tw), ap));
 		for (tw = t->args; *tw != NULL; )
 			*rw++ = wdcopy(*tw++, ap);
 		*rw = NULL;
@@ -596,7 +594,7 @@ wdstrip(const char *wp)
 		}
 }
 
-static	struct ioword **
+static struct ioword **
 iocopy(struct ioword **iow, Area *ap)
 {
 	struct ioword **ior;
@@ -628,7 +626,6 @@ iocopy(struct ioword **iow, Area *ap)
 /*
  * free tree (for function definition)
  */
-
 void
 tfree(struct op *t, Area *ap)
 {
@@ -647,7 +644,10 @@ tfree(struct op *t, Area *ap)
 	}
 
 	if (t->args != NULL) {
-		for (w = t->args; *w != NULL; w++)
+		union mksh_ccphack cw;
+		/* XXX we assume the caller is right */
+		cw.ro = t->args;
+		for (w = cw.rw; *w != NULL; w++)
 			afree((void*)*w, ap);
 		afree((void*)t->args, ap);
 	}
@@ -661,7 +661,7 @@ tfree(struct op *t, Area *ap)
 	afree((void*)t, ap);
 }
 
-static	void
+static void
 iofree(struct ioword **iow, Area *ap)
 {
 	struct ioword **iop;
diff --git a/var.c b/var.c
index 9fcf2ec..568e0ab 100644
--- a/var.c
+++ b/var.c
@@ -2,7 +2,7 @@
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/var.c,v 1.35 2007/03/03 21:36:08 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/var.c,v 1.36 2007/03/04 00:13:17 tg Exp $");
 
 /*
  * Variables
@@ -32,7 +32,7 @@ void
 newblock(void)
 {
 	struct block *l;
-	static char *empty[] = { null };
+	static const char *empty[] = { null };
 
 	l = (struct block *) alloc(sizeof(struct block), ATEMP);
 	l->flags = 0;
@@ -1149,7 +1149,7 @@ arrayname(const char *str)
 /* Set (or overwrite, if !reset) the array variable var to the values in vals.
  */
 void
-set_array(const char *var, int reset, char **vals)
+set_array(const char *var, int reset, const char **vals)
 {
 	struct tbl *vp, *vq;
 	int i;