Rename char *nvenv to void *nvmeta (re: 4d68815)

The previous commit removed the redundant use of the nvenv pointer
of struct Namval to point directly to values in environ[]. That was
its original purpose, but there are many remaining additional uses.
So far, I've discovered:
    - help string for type commands (typeset -T -h)
      (typeset.c, nvtype.c)
    - pointer to dimension 2+ array
      (array.c and loads of other places)
    - compound variable (NV_COMVAR, NV_TABLE)
      (arith.c, nvdisc.c, name.c)
    - struct slnod: linked list of stacks (for functions;
      see also sh_funstaks())
      (xec.c, name.c)
      name.c:2375
    - flaggery for builtins (purpose to be worked out):
      (nvdisc.c, path.c)

So, this follow-up commit has no actual code changes; it is for
code legibility. It:

- Removes the now-unused NV_IMPORT attribute. It shared a bit value
  with NV_MINIMAL, so the few remaining uses of it in the code has
  been changed to NV_MIMIMAL to avoid potential bugs.
- Renames nvenv to nvmeta, in recognition of the fact that it is
  used for many kinds of purposes.
- Makes nvmeta a void pointer instead of a char pointer.
- Accordingly removes now-redundant explicit typecasts.

src/cmd/ksh93/bltins/read.c

@@ -277,11 +277,11 @@ int sh_readline(char **names, volatile int fd, int flags, ssize_t size, Sflong_t
 		}
 		else if(flags&C_FLAG)
 		{
-			char *sp =  np->nvenv;
+			void *sp = np->nvmeta;
 			delim = -1;
 			nv_unset(np);
 			if(!nv_isattr(np,NV_MINIMAL))
-				np->nvenv = sp;
+				np->nvmeta = sp;
 			nv_setvtree(np);
 		}
 		else
@@ -499,7 +499,7 @@ int sh_readline(char **names, volatile int fd, int flags, ssize_t size, Sflong_t
 					var = sh_memdup(var,c+1);
 				nv_putval(np,var,NV_RAW);
 				nv_setsize(np,c);
-				if(!nv_isattr(np,NV_IMPORT|NV_EXPORT)  && (mp=(Namval_t*)np->nvenv))
+				if(!nv_isattr(np,NV_MINIMAL|NV_EXPORT) && (mp = np->nvmeta))
 					nv_setsize(mp,c);
 			}
 		}

src/cmd/ksh93/bltins/typeset.c

@@ -549,7 +549,7 @@ int    b_typeset(int argc,char *argv[],Shbltin_t *context)
 		}
 		else if(nv_isnull(tdata.tp) && sh.envlist)   /* only create a type command if there were assignment(s) */
 			nv_newtype(tdata.tp);
-		tdata.tp->nvenv = tdata.help;
+		tdata.tp->nvmeta = tdata.help;
 		flag &= ~NV_TYPE;
 		if(nv_isattr(tdata.tp,NV_TAGGED))
 		{
@@ -790,7 +790,7 @@ static int     setall(char **argv,int flag,Dt_t *troot,struct tdata *tp)
 			}
 			if(nv_isnull(np) && !nv_isarray(np) && nv_isattr(np,NV_NOFREE))
 				nv_offattr(np,NV_NOFREE);
-			else if(tp->tp && !nv_isattr(np,NV_MINIMAL|NV_EXPORT) && (mp=(Namval_t*)np->nvenv) && (ap=nv_arrayptr(mp)) && (ap->nelem&ARRAY_TREE))
+			else if(tp->tp && !nv_isattr(np,NV_MINIMAL|NV_EXPORT) && (mp = np->nvmeta) && (ap = nv_arrayptr(mp)) && (ap->nelem & ARRAY_TREE))
 			{
 				errormsg(SH_DICT,ERROR_exit(1),e_typecompat,nv_name(np));
 				UNREACHABLE();
@@ -958,7 +958,7 @@ static int     setall(char **argv,int flag,Dt_t *troot,struct tdata *tp)
 			}
 			if(tp->help && !nv_isattr(np,NV_MINIMAL|NV_EXPORT))
 			{
-				np->nvenv = tp->help;
+				np->nvmeta = tp->help;
 				nv_onattr(np,NV_EXPORT);
 			}
 			if(last)

src/cmd/ksh93/include/name.h

@@ -24,7 +24,7 @@
 #define _NV_PRIVATE	\
 	Namfun_t	*nvfun;		/* pointer to trap functions */ \
 	union Value	nvalue; 	/* value field */ \
-	char		*nvenv;		/* pointer to environment name */ 
+	void		*nvmeta;	/* pointer to any of various kinds of type-dependent data */
 
 #include	<ast.h>
 #include	<cdt.h>
@@ -116,7 +116,7 @@ struct Ufunction
 /* attributes of Namval_t items */
 
 /* The following attributes are for internal use */
-#define NV_NOCHANGE	(NV_EXPORT|NV_IMPORT|NV_RDONLY|NV_TAGGED|NV_NOFREE|NV_ARRAY)
+#define NV_NOCHANGE	(NV_EXPORT|NV_MINIMAL|NV_RDONLY|NV_TAGGED|NV_NOFREE|NV_ARRAY)
 #define NV_ATTRIBUTES	(~(NV_NOSCOPE|NV_ARRAY|NV_NOARRAY|NV_IDENT|NV_ASSIGN|NV_REF|NV_VARNAME|NV_STATIC))
 #define NV_PARAM	NV_NODISC	/* expansion use positional params */
 
@@ -130,15 +130,15 @@ struct Ufunction
 #define NV_STATICF	NV_INTEGER		/* static class function */
 
 #define NV_NOPRINT	(NV_LTOU|NV_UTOL)	/* do not print */
-#define NV_NOALIAS	(NV_NOPRINT|NV_IMPORT)
+#define NV_NOALIAS	(NV_NOPRINT|NV_MINIMAL)
 #define NV_NOEXPAND	NV_RJUST		/* do not expand alias */
 #define NV_BLTIN	(NV_NOPRINT|NV_EXPORT)
 #define BLT_ENV		(NV_RDONLY)		/* non-stoppable,
 						 * can modify environment */
 #define BLT_SPC		(NV_LJUST)		/* special built-ins */
 #define BLT_EXIT	(NV_RJUST)		/* exit value can be > 255 or < 0 */
 #define BLT_DCL		(NV_TAGGED)		/* declaration command */
-#define BLT_NOSFIO	(NV_IMPORT)		/* doesn't use sfio */
+#define BLT_NOSFIO	(NV_MINIMAL)		/* doesn't use sfio */
 #define NV_OPTGET	(NV_BINARY)		/* function calls getopts */
 #define nv_isref(n)	(nv_isattr((n),NV_REF|NV_TAGGED|NV_FUNCT)==NV_REF)
 #define is_abuiltin(n)	(nv_isattr(n,NV_BLTIN|NV_INTEGER)==NV_BLTIN)

src/cmd/ksh93/include/nval.h

@@ -137,8 +137,7 @@ struct Namval
 #define NV_ARRAY	0x400	/* node is an array */
 #define NV_REF		0x4000	/* reference bit */
 #define NV_TABLE	0x800	/* node is a dictionary table */
-#define NV_IMPORT	0x1000	/* value imported from environment */
-#define NV_MINIMAL	NV_IMPORT	/* node does not contain all fields */
+#define NV_MINIMAL	0x1000	/* node does not contain all fields */
 #if SHOPT_OPTIMIZE
 #define NV_NOOPTIMIZE	NV_TABLE	/* disable loop invariants optimizer */
 #else

src/cmd/ksh93/sh/arith.c

@@ -182,7 +182,7 @@ static Namval_t *scope(Namval_t *np,struct lval *lvalue,int assign)
 				if(ap && !ap->table)
 					ap->table = dtopen(&_Nvdisc,Dtoset);
 				if(ap && ap->table && (nq=nv_search(nv_getsub(np),ap->table,NV_ADD)))
-					nq->nvenv = (char*)np;
+					nq->nvmeta = np;
 				if(nq && nv_isnull(nq))
 					np = nv_arraychild(np,nq,0);
 			}

src/cmd/ksh93/sh/array.c

@@ -378,7 +378,7 @@ static Namval_t *array_find(Namval_t *np,Namarr_t *arp, int flag)
 			sfprintf(sh.strbuf,"%d",ap->cur);
 			cp = sfstruse(sh.strbuf);
 			mp = nv_search(cp, ap->header.table, NV_ADD);
-			mp->nvenv = (char*)np;
+			mp->nvmeta = np;
 			nv_arraychild(np,mp,0);
 		}
 		if(up->np && array_isbit(ap->bits,ap->cur,ARRAY_CHILD))
@@ -446,7 +446,7 @@ static Namfun_t *array_clone(Namval_t *np, Namval_t *mp, int flags, Namfun_t *fp
 			do
 			{
 				if(nq=nv_opensub(np))
-					nq->nvenv = (void*)mp;
+					nq->nvmeta = mp;
 			}
 			while(nv_nextsub(np));
 		}
@@ -790,7 +790,7 @@ static void array_copytree(Namval_t *np, Namval_t *mp)
 	nv_disc(np,(Namfun_t*)fp, NV_FIRST);
 	fp->nofree |= 1;
 	nv_onattr(np,NV_ARRAY);
-	mp->nvenv = (char*)np;
+	mp->nvmeta = np;
 }
 
 /*
@@ -1028,15 +1028,15 @@ Namval_t *nv_arraychild(Namval_t *np, Namval_t *nq, int c)
 	if((tp=nv_type(np)) || c)
 	{
 		ap->nelem |= ARRAY_NOCLONE;
-		nq->nvenv = (char*)np;
+		nq->nvmeta = np;
 		if(c=='t')
 			nv_clone(tp,nq, 0);
 		else
 			nv_clone(np, nq, NV_NODISC);
 		nv_offattr(nq,NV_ARRAY);
 		ap->nelem &= ~ARRAY_NOCLONE;
 	}
-	nq->nvenv = (char*)np;
+	nq->nvmeta = np;
 	if((fp=nq->nvfun) && fp->disc && fp->disc->setdisc && (fp = nv_disc(nq,fp,NV_POP)))
 		free(fp);
 	if(!ap->fun)
@@ -1237,7 +1237,7 @@ Namval_t *nv_putsub(Namval_t *np,char *sp,long mode)
 					sfprintf(sh.strbuf,"%d",ap->cur);
 					cp = sfstruse(sh.strbuf);
 					mp = nv_search(cp, ap->header.table, NV_ADD);
-					mp->nvenv = (char*)np;
+					mp->nvmeta = np;
 					nv_arraychild(np,mp,0);
 					nv_setvtree(mp);
 				}
@@ -1720,7 +1720,7 @@ void *nv_associative(Namval_t *np,const char *sp,int mode)
 		return ap->cur;
 	    case NV_ACURRENT:
 		if(ap->cur)
-			ap->cur->nvenv = (char*)np;
+			ap->cur->nvmeta = np;
 		return ap->cur;
 	    case NV_ANAME:
 		if(ap->cur)
@@ -1749,7 +1749,7 @@ void *nv_associative(Namval_t *np,const char *sp,int mode)
 			if((mp || (mp=nv_search(sp,ap->header.table,mode))) && nv_isnull(mp) && (mode&NV_ADD))
 			{
 				nv_onattr(mp,type);
-				mp->nvenv = (char*)np;
+				mp->nvmeta = np;
 				if((mode&NV_ADD) && nv_type(np)) 
 					nv_arraychild(np,mp,0);
 				if(sh.subshell)

src/cmd/ksh93/sh/init.c

@@ -789,7 +789,7 @@ static void put_lastarg(Namval_t* np,const char *val,int flags,Namfun_t *fp)
 		nv_offattr(np,NV_NOFREE);
 	sh.lastarg = (char*)val;
 	nv_offattr(np,NV_EXPORT);
-	np->nvenv = 0;
+	np->nvmeta = NULL;
 }
 
 static void match2d(struct match *mp)
@@ -1950,7 +1950,7 @@ Dt_t *sh_inittree(const struct shtable2 *name_vals)
 			np->nvname = (char*)tp->sh_name;
 			treep = base_treep;
 		}
-		np->nvenv = 0;
+		np->nvmeta = NULL;
 		if(name_vals==(const struct shtable2*)shtab_builtins)
 			np->nvalue.bfp = (void*)((struct shtable3*)tp)->sh_value;
 		else
@@ -2032,7 +2032,7 @@ static void env_import_attributes(char *next)
 		if(next = strchr(++cp,'='))
 			*next = 0;
 		np = nv_search(cp+2,sh.var_tree,NV_ADD);
-		if(np!=SHLVL && nv_isattr(np,NV_IMPORT|NV_EXPORT))
+		if(np!=SHLVL && nv_isattr(np,NV_EXPORT))
 		{
 			int flag = *(unsigned char*)cp-' ';
 			int size = *(unsigned char*)(cp+1)-' ';
@@ -2064,7 +2064,7 @@ static void env_import_attributes(char *next)
 			flag &= ~NV_RDONLY;	/* refuse to import readonly attribute */
 			if(!flag)
 				continue;
-			nv_newattr(np,flag|NV_IMPORT|NV_EXPORT,size);
+			nv_newattr(np,flag|NV_EXPORT,size);
 		}
 	}
 	return;

src/cmd/ksh93/sh/name.c

@@ -1181,7 +1181,7 @@ Namval_t *nv_create(const char *name,  Dt_t *root, int flags, Namfun_t *dp)
 							if(n && ap && !ap->table)
 								ap->table = dtopen(&_Nvdisc,Dtoset);
 							if(ap && ap->table && (nq=nv_search(sub,ap->table,n)))
-								nq->nvenv = (char*)np;
+								nq->nvmeta = np;
 							if(nq && nv_isnull(nq))
 								nq = nv_arraychild(np,nq,c);
 						}
@@ -2404,7 +2404,7 @@ static void table_unset(Dt_t *root, int flags, Dt_t *oroot)
  *   will retain its attributes.
  *   <flags> can contain NV_RDONLY to override the readonly attribute
  *	being cleared.
- *   <flags> can contain NV_EXPORT to override preserve nvenv
+ *   <flags> can contain NV_EXPORT to preserve nvmeta.
  */
 void	_nv_unset(Namval_t *np,int flags)
 {
@@ -2421,7 +2421,7 @@ void	_nv_unset(Namval_t *np,int flags)
 	}
 	if(is_afunction(np) && np->nvalue.ip)
 	{
-		struct slnod *slp = (struct slnod*)(np->nvenv);
+		struct slnod *slp = np->nvmeta;
 		if(np->nvalue.rp->running)
 		{
 			np->nvalue.rp->running |= 1;
@@ -2531,7 +2531,7 @@ void	_nv_unset(Namval_t *np,int flags)
 			if(nv_isattr(np,NV_EXPORT) && !strchr(np->nvname,'['))
 				env_change();
 			if(!(flags&NV_EXPORT) ||  nv_isattr(np,NV_EXPORT))
-				np->nvenv = 0;
+				np->nvmeta = NULL;
 			nv_setattr(np,0);
 		}
 		else
@@ -3156,16 +3156,17 @@ int nv_rename(Namval_t *np, int flags)
 	Namval_t		*last_table = sh.last_table;
 	Dt_t			*last_root = sh.last_root;
 	Dt_t			*hp = 0;
-	char			*nvenv=0,*prefix=sh.prefix;
+	void			*nvmeta = NULL;
+	char			*prefix = sh.prefix;
 	Namarr_t		*ap;
 	if(nv_isattr(np,NV_PARAM) && sh.st.prevst)
 	{
 		if(!(hp=(Dt_t*)sh.st.prevst->save_tree))
 			hp = dtvnext(sh.var_tree);
 	}
 	if(!nv_isattr(np,NV_MINIMAL))
-		nvenv = np->nvenv;
-	if(nvenv || (cp = nv_name(np)) && nv_isarray(np) && cp[strlen(cp)-1] == ']')
+		nvmeta = np->nvmeta;
+	if(nvmeta || (cp = nv_name(np)) && nv_isarray(np) && cp[strlen(cp)-1] == ']')
 		arraynp = 1;
 	if(!(cp=nv_getval(np)))
 	{
@@ -3215,12 +3216,12 @@ int nv_rename(Namval_t *np, int flags)
 		{
 			if(ap = nv_arrayptr(np))
 				ap->nelem++;
-			mp->nvenv = nvenv = (void*)np;
+			mp->nvmeta = nvmeta = np;
 		}
 	}
 	if(mp)
 	{
-		nvenv = (char*)np;
+		nvmeta = np;
 		np = mp;
 	}
 	if(nr==np)
@@ -3244,7 +3245,7 @@ int nv_rename(Namval_t *np, int flags)
 	sh.last_root = last_root;
 	if(flags&NV_MOVE)
 	{
-		if(arraynp && !nv_isattr(np,NV_MINIMAL) && (mp=(Namval_t*)np->nvenv) && (ap=nv_arrayptr(mp)) && !ap->fun)
+		if(arraynp && !nv_isattr(np,NV_MINIMAL) && (mp = np->nvmeta) && (ap = nv_arrayptr(mp)) && !ap->fun)
 			ap->nelem++;
 	}
 	if((nv_arrayptr(nr) && !arraynr) || nv_isvtree(nr))
@@ -3256,7 +3257,7 @@ int nv_rename(Namval_t *np, int flags)
 			if(ap->table)
 				mp = nv_search(nv_getsub(np),ap->table,NV_ADD);
 			nv_arraychild(np,mp,0);
-			nvenv = (void*)np;
+			nvmeta = np;
 		}
 		else
 			mp = np;
@@ -3282,10 +3283,10 @@ int nv_rename(Namval_t *np, int flags)
 		}
 		else
 			nv_clone(nr,mp,(flags&NV_MOVE)|NV_COMVAR);
-		mp->nvenv = nvenv;
+		mp->nvmeta = nvmeta;
 		if(flags&NV_MOVE)
 		{
-			if(arraynr && !nv_isattr(nr,NV_MINIMAL) && (mp=(Namval_t*)nr->nvenv) && (ap=nv_arrayptr(mp)))
+			if(arraynr && !nv_isattr(nr,NV_MINIMAL) && (mp = nr->nvmeta) && (ap = nv_arrayptr(mp)))
 			{
 				nv_putsub(mp,nr->nvname,0);
 				_nv_unset(mp,0);
@@ -3298,7 +3299,7 @@ int nv_rename(Namval_t *np, int flags)
 		nv_putval(np,nv_getval(nr),0);
 		if(flags&NV_MOVE)
 		{
-			if(!nv_isattr(nr,NV_MINIMAL) && (mp=(Namval_t*)(nr->nvenv)) && (ap=nv_arrayptr(mp)))
+			if(!nv_isattr(nr,NV_MINIMAL) && (mp = nr->nvmeta) && (ap = nv_arrayptr(mp)))
 				ap->nelem--;
 			_nv_unset(nr,0);
 		}
@@ -3552,9 +3553,9 @@ char *nv_name(Namval_t *np)
 #if SHOPT_FIXEDARRAY
 	ap = nv_arrayptr(np);
 #endif /* SHOPT_FIXEDARRAY */
-	if(!nv_isattr(np,NV_MINIMAL|NV_EXPORT) && np->nvenv)
+	if(!nv_isattr(np,NV_MINIMAL|NV_EXPORT) && np->nvmeta)
 	{
-		Namval_t *nq= sh.last_table, *mp= (Namval_t*)np->nvenv;
+		Namval_t *nq = sh.last_table, *mp = np->nvmeta;
 		if(np==sh.last_table)
 			sh.last_table = 0;
 		if(nv_isarray(mp))