Implementation of the local builtin with support for dynamic local scopes

src/cmd/ksh93/bltins/cflow.c

@@ -44,7 +44,7 @@
 int b_return(int n, char *argv[],Shbltin_t *context)
 {
  /* 'return' outside of function, dotscript and profile behaves like 'exit' */
- char do_exit = **argv=='e' || sh.fn_depth==0 && sh.dot_depth==0 && !sh_isstate(SH_PROFILE);
+ char do_exit = **argv=='e' || !sh.infunction && !sh_isstate(SH_PROFILE);
  NOT_USED(context);
  while((n = optget(argv, **argv=='e' ? sh_optexit : sh_optreturn))) switch(n)
  {

src/cmd/ksh93/bltins/misc.c

@@ -2,7 +2,7 @@
 * *
 * This software is part of the ast package *
 * Copyright (c) 1982-2012 AT&T Intellectual Property *
-* Copyright (c) 2020-2023 Contributors to ksh 93u+m *
+* Copyright (c) 2020-2024 Contributors to ksh 93u+m *
 * and is licensed under the *
 * Eclipse Public License, Version 2.0 *
 * *
@@ -56,8 +56,6 @@
 #include <times.h>
 #endif
 
-#define DOTMAX MAXDEPTH /* maximum level of . nesting */
-
 /*
  * Handler function for nv_scan() that unsets a variable's export attribute
  */
@@ -215,16 +213,17 @@ int b_eval(int argc,char *argv[], Shbltin_t *context)
 #endif
 int b_dot_cmd(int n,char *argv[],Shbltin_t *context)
 {
- char *script;
- Namval_t *np;
- int jmpval;
- struct sh_scoped savst, *prevscope = sh.st.self;
- char *filename=0, *buffer=0, *tofree;
- int fd;
- struct dolnod *saveargfor;
- volatile struct dolnod *argsave=0;
- struct checkpt buff;
- Sfio_t *iop=0;
+ char *script;
+ Namval_t *np;
+ struct sh_scoped savst, *prevscope = sh.st.self;
+ char *filename=0, *buffer=0, *tofree;
+ int fd, dtret, jmpval, save_invoc_local;
+ char save_infunction = -1;
+ struct dolnod *saveargfor;
+ volatile struct dolnod *argsave=0;
+ struct checkpt buff;
+ Sfio_t *iop=0;
+ Namval_t *nspace = sh.namespace;
  NOT_USED(context);
  while (n = optget(argv,sh_optdot)) switch (n)
  {
@@ -242,61 +241,61 @@ int b_dot_cmd(int n,char *argv[],Shbltin_t *context)
  errormsg(SH_DICT,ERROR_usage(2),"%s",optusage(NULL));
  UNREACHABLE();
  }
- if(sh.dot_depth >= DOTMAX)
+ if(sh.dot_depth >= MAXDEPTH)
  {
  errormsg(SH_DICT,ERROR_exit(1),e_toodeep,script);
  UNREACHABLE();
  }
- if(!(np=sh.posix_fun))
+ /* check for KornShell style function first */
+ np = nv_search(script,sh.fun_tree,0);
+ if(np && is_afunction(np) && !nv_isattr(np,NV_FPOSIX) && !(sh_isoption(SH_POSIX) && sh.bltindata.bnode==SYSDOT))
  {
- /* check for KornShell style function first */
- np = nv_search(script,sh.fun_tree,0);
- if(np && is_afunction(np) && !nv_isattr(np,NV_FPOSIX) && !(sh_isoption(SH_POSIX) && sh.bltindata.bnode==SYSDOT))
+ if(!np->nvalue.ip)
  {
- if(!np->nvalue.ip)
+ path_search(script,NULL,0);
+ if(np->nvalue.ip)
  {
- path_search(script,NULL,0);
- if(np->nvalue.ip)
- {
- if(nv_isattr(np,NV_FPOSIX))
- np = 0;
- }
- else
- {
- errormsg(SH_DICT,ERROR_exit(1),e_found,script);
- UNREACHABLE();
- }
+ if(nv_isattr(np,NV_FPOSIX))
+ np = 0;
  }
- }
- else
- np = 0;
- if(!np)
- {
- if((fd=path_open(script,path_get(script))) < 0)
+ else
  {
- errormsg(SH_DICT,ERROR_system(1),e_open,script);
+ errormsg(SH_DICT,ERROR_exit(1),e_found,script);
  UNREACHABLE();
  }
- filename = path_fullname(stkptr(sh.stk,PATH_OFFSET));
  }
  }
+ else
+ np = 0;
+ if(!np)
+ {
+ /* Open the dot script */
+ if((fd=path_open(script,path_get(script))) < 0)
+ {
+ errormsg(SH_DICT,ERROR_system(1),e_open,script);
+ UNREACHABLE();
+ }
+ filename = path_fullname(stkptr(sh.stk,PATH_OFFSET));
+ }
+ else
+ {
+ /* We are executing a KornShell function as a dot script */
+ save_infunction = sh.infunction;
+ sh.infunction = FUN_KSHDOT;
+ }
  *prevscope = sh.st;
- sh.st.lineno = np?((struct functnod*)nv_funtree(np))->functline:1;
+ sh.st.lineno = np ? ((struct functnod*)nv_funtree(np))->functline : 1;
  sh.st.save_tree = sh.var_tree;
  if(filename)
- {
  sh.st.filename = filename;
- sh.st.lineno = 1;
- }
  sh.st.prevst = prevscope;
  sh.st.self = &savst;
  sh.topscope = (Shscope_t*)sh.st.self;
  prevscope->save_tree = sh.var_tree;
  tofree = sh.st.filename;
  if(np)
  sh.st.filename = np->nvalue.rp->fname;
- nv_putval(SH_PATHNAMENOD, sh.st.filename ,NV_NOFREE);
- sh.posix_fun = 0;
+ nv_putval(SH_PATHNAMENOD,sh.st.filename,NV_NOFREE);
  if(np || argv[1])
  argsave = sh_argnew(argv,&saveargfor);
  sh_pushcontext(&buff,SH_JMPDOT);
@@ -308,9 +307,11 @@ int b_dot_cmd(int n,char *argv[],Shbltin_t *context)
  sh.dot_depth++;
  update_sh_level();
  if(np)
+ /* Execute the function as though it were a dot script */
  sh_exec((Shnode_t*)(nv_funtree(np)),sh_isstate(SH_ERREXIT));
  else
  {
+ /* Run the dot script */
  buffer = sh_malloc(IOBSIZE+1);
  iop = sfnew(NULL,buffer,IOBSIZE,fd,SF_READ);
  sh_offstate(SH_NOFORK);
@@ -331,12 +332,14 @@ int b_dot_cmd(int n,char *argv[],Shbltin_t *context)
  prevscope->dolc = sh.st.dolc;
  prevscope->dolv = sh.st.dolv;
  }
- if (sh.st.self != &savst)
+ if(sh.st.self != &savst)
  *sh.st.self = sh.st;
- /* only restore the top Shscope_t portion for POSIX functions */
+ if(save_infunction != -1)
+ sh.infunction = save_infunction;
+ /* Only restore the top Shscope_t portion for functions */
  memcpy(&sh.st, prevscope, sizeof(Shscope_t));
  sh.topscope = (Shscope_t*)prevscope;
- nv_putval(SH_PATHNAMENOD, sh.st.filename ,NV_NOFREE);
+ nv_putval(SH_PATHNAMENOD,sh.st.filename,NV_NOFREE);
  if(jmpval && jmpval!=SH_JMPFUN)
  siglongjmp(*sh.jmplist,jmpval);
  return sh.exitval;

src/cmd/ksh93/bltins/typeset.c

@@ -21,6 +21,8 @@
  * export [-p] [arg...]
  * readonly [-p] [arg...]
  * typeset [options] [arg...]
+ * declare [options] [arg...]
+ * local [options] [arg...]
  * autoload [options] [arg...]
  * compound [options] [arg...]
  * float [options] [arg...]
@@ -208,6 +210,7 @@ int b_alias(int argc,char *argv[],Shbltin_t *context)
  /* for the dictionary generator */
  int b_autoload(int argc,char *argv[],Shbltin_t *context){}
  int b_compound(int argc,char *argv[],Shbltin_t *context){}
+ int b_declare(int argc,char *argv[],Shbltin_t *context){}
  int b_float(int argc,char *argv[],Shbltin_t *context){}
  int b_functions(int argc,char *argv[],Shbltin_t *context){}
  int b_integer(int argc,char *argv[],Shbltin_t *context){}
@@ -221,17 +224,19 @@ int b_typeset(int argc,char *argv[],Shbltin_t *context)
  const char *optstring = sh_opttypeset;
  Namdecl_t *ntp = (Namdecl_t*)context->ptr;
  Dt_t *troot;
- int isfloat=0, isadjust=0, shortint=0, sflag=0;
+ int isfloat=0, isadjust=0, shortint=0, sflag=0, local, declare, scoping_flags = 0;
 
  memset(&tdata,0,sizeof(tdata));
  troot = sh.var_tree;
+ declare = argv[0][0] == 'd';
+ local = argv[0][0] == 'l';
  if(ntp) /* type declaration command added using 'typeset -T' or 'enum' */
  {
  tdata.tp = ntp->tp;
  opt_info.disc = (Optdisc_t*)ntp->optinfof;
  optstring = ntp->optstring;
  }
- else if(argv[0][0] != 't') /* not <t>ypeset */
+ else if(argv[0][0] != 't' && !declare && !local) /* not <t>ypeset, <d>eclare or <l>ocal */
  {
  char **new_argv = (char **)stkalloc(sh.stk, (argc + 2) * sizeof(char*));
  error_info.id = new_argv[0] = SYSTYPESET->nvname;
@@ -430,7 +435,19 @@ int b_typeset(int argc,char *argv[],Shbltin_t *context)
  flag |= (NV_EXPORT|NV_IDENT);
  break;
  case 'g':
+ flag &= ~(NV_SCOPES);
  flag |= NV_GLOBAL;
+ scoping_flags++;
+ break;
+ case 'D':
+ flag &= ~(NV_SCOPES);
+ flag |= NV_DYNAMIC;
+ scoping_flags++;
+ break;
+ case 'P':
+ flag &= ~(NV_SCOPES);
+ flag |= NV_STATSCOPE;
+ scoping_flags++;
  break;
  case ':':
  errormsg(SH_DICT,2, "%s", opt_info.arg);
@@ -444,6 +461,12 @@ int b_typeset(int argc,char *argv[],Shbltin_t *context)
 endargs:
  argv += opt_info.index;
  opt_info.disc = 0;
+ /* 'local' builtin */
+ if(local && !sh.infunction)
+ {
+ errormsg(SH_DICT,ERROR_exit(1), "can only be used in a function");
+ UNREACHABLE();
+ }
  /* handle argument of + and - specially */
  if(*argv && argv[0][1]==0 && (*argv[0]=='+' || *argv[0]=='-'))
  tdata.aflag = *argv[0];
@@ -466,9 +489,9 @@ int b_typeset(int argc,char *argv[],Shbltin_t *context)
  errormsg(SH_DICT,2,e_optincompat1,"-m");
  error_info.errors++;
  }
- if((flag&NV_REF) && (flag&~(NV_REF|NV_IDENT|NV_ASSIGN|NV_GLOBAL)))
+ if((flag&NV_REF) && (flag&~(NV_REF|NV_IDENT|NV_ASSIGN|NV_SCOPES)))
  {
- errormsg(SH_DICT,2,e_optincompat2,"-n","other options except -g");
+ errormsg(SH_DICT,2,e_optincompat2,"-n","other options except -P, -D and -g");
  error_info.errors++;
  }
  if((flag&NV_TYPE) && (flag&~(NV_TYPE|NV_VARNAME|NV_ASSIGN)))
@@ -497,11 +520,23 @@ int b_typeset(int argc,char *argv[],Shbltin_t *context)
  errormsg(SH_DICT,ERROR_exit(2),"option argument cannot be greater than %d",SHRT_MAX);
  UNREACHABLE();
  }
- if((flag&NV_GLOBAL) && sh.mktype)
+ if((flag&NV_SCOPES) && sh.mktype)
  {
- errormsg(SH_DICT,ERROR_exit(2),"-g: type members cannot be global");
+ errormsg(SH_DICT,ERROR_exit(2),"type members cannot use the scoping flags -P, -D and -g");
  UNREACHABLE();
  }
+ if(scoping_flags > 1)
+ {
+ errormsg(SH_DICT,ERROR_exit(2),"the scoping flags -P, -D and -g cannot be combined");
+ UNREACHABLE();
+ }
+ if(troot==sh.var_tree && !sh.mktype && sh.infunction && !(flag&(NV_SCOPES)))
+ {
+ if(local || declare)
+ flag |= NV_DYNAMIC;
+ else if(sh.infunction==FUN_POSIX)
+ flag |= NV_GLOBAL;
+ }
  if(isfloat)
  flag |= NV_DOUBLE;
  if(sflag)
@@ -511,7 +546,7 @@ int b_typeset(int argc,char *argv[],Shbltin_t *context)
  else if(!sh.typeinit)
  flag |= NV_STATIC|NV_IDENT;
  }
- if(sh.fn_depth && !tdata.pflag)
+ if(sh.infunction < FUN_KSHDOT && !tdata.pflag)
  flag |= NV_NOSCOPE;
  if(tdata.help)
  tdata.help = sh_strdup(tdata.help);
@@ -645,7 +680,7 @@ static int setall(char **argv,int flag,Dt_t *troot,struct tdata *tp)
 {
  char *name;
  char *last = 0;
- int nvflags=(flag&(NV_ARRAY|NV_NOARRAY|NV_VARNAME|NV_IDENT|NV_ASSIGN|NV_STATIC|NV_MOVE));
+ int nvflags=(flag&(NV_ARRAY|NV_NOARRAY|NV_VARNAME|NV_IDENT|NV_ASSIGN|NV_STATIC|NV_MOVE|NV_DYNAMIC));
  int r=0, ref=0, comvar=(flag&NV_COMVAR),iarray=(flag&NV_IARRAY);
  Dt_t *save_vartree = NULL;
  Namval_t *save_namespace = NULL;

src/cmd/ksh93/data/builtins.c

@@ -70,6 +70,8 @@ const struct shtable3 shtab_builtins[] =
  "functions", NV_BLTIN|BLT_ENV, bltin(typeset),
  "integer", NV_BLTIN|BLT_ENV|BLT_DCL, bltin(typeset),
  "nameref", NV_BLTIN|BLT_ENV|BLT_DCL, bltin(typeset),
+ "local", NV_BLTIN|BLT_ENV|BLT_DCL, bltin(typeset),
+ "declare", NV_BLTIN|BLT_ENV|BLT_DCL, bltin(typeset),
  "test", NV_BLTIN|BLT_ENV, bltin(test),
  "[", NV_BLTIN|BLT_ENV, bltin(test),
  "let", NV_BLTIN|BLT_ENV, bltin(let),
@@ -729,7 +731,7 @@ const char sh_optexport[] =
  "[+>0?An error occurred.]"
 "}"
 
-"[+SEE ALSO?\bsh\b(1), \btypeset\b(1)]"
+"[+SEE ALSO?\bsh\b(1), \btypeset\b(1), \blocal\b(1)]"
 ;
 
 const char sh_optgetopts[] =
@@ -1541,7 +1543,7 @@ const char sh_optreadonly[] =
  "[+>0?An error occurred.]"
 "}"
 
-"[+SEE ALSO?\bsh\b(1), \btypeset\b(1)]"
+"[+SEE ALSO?\bsh\b(1), \btypeset\b(1), \blocal\b(1)]"
 ;
 
 const char sh_optredirect[] =
@@ -1691,6 +1693,7 @@ const char sh_optksh[] =
 
 "[+SEE ALSO?\bset\b(1), \bbuiltin\b(1)]"
 ;
+
 const char sh_optset[] =
 "+[-1c?\n@(#)$Id: set (ksh 93u+m) 2023-05-18 $\n]"
 "[--catalog?" SH_DICT "]"
@@ -1727,11 +1730,9 @@ const char sh_optset[] =
  "[+>0?An error occurred.]"
 "}"
 
-"[+SEE ALSO?\btypeset\b(1), \bshift\b(1)]"
+"[+SEE ALSO?\btypeset\b(1), \blocal\b(1), \bshift\b(1)]"
 ;
 
-
-
 const char sh_optshift[] =
 "[-1c?\n@(#)$Id: shift (AT&T Research) 1999-07-07 $\n]"
 "[--catalog?" SH_DICT "]"
@@ -1856,7 +1857,11 @@ const char sh_opttypeset[] =
 "[+?When \btypeset\b is called inside a function defined with the "
  "\bfunction\b reserved word, and \aname\a does not contain a "
  "\b.\b, then a local variable statically scoped to that function "
- "will be created.]"
+ "will be created. If \btypeset\b is used in a POSIX function, a "
+ "variable is created in the global scope.]"
+"[+?\btypeset\b can also be invoked as \bdeclare\b, or (in functions "
+ "only) as \blocal\b. A variable created or modified by either \bdeclare\b "
+ "or \blocal\b is given a dynamic scope.]"
 "[+?Not all option combinations are possible. For example, the numeric "
  "options \b-i\b, \b-E\b, and \b-F\b cannot be specified with "
  "the justification options \b-L\b, \b-R\b, and \b-Z\b.]"
@@ -1912,7 +1917,10 @@ const char sh_opttypeset[] =
 "[n?Name reference. The value is the name of a variable that \aname\a "
  "references. \aname\a cannot contain a \b.\b.]"
 "[p?Causes the output to be in a format that can be used as input to the "
- "shell to recreate the attributes for variables.]"
+ "shell to recreate the attributes for variables. If this flag "
+ "is used by \btypeset\b in a POSIX function without also passing "
+ "\b-D\b or \b-P\b, the local scope is ignored and \btypeset\b will "
+ "only use the global scope.]"
 "[r?Enables readonly. Once enabled it cannot be disabled. See "
  "\breadonly\b(1).]"
 "[s?Used with \b-i\b to restrict integer size to short.]"
@@ -1962,6 +1970,8 @@ const char sh_opttypeset[] =
  "unset prior to processing the assignment list.]"
 "[T]:?[tname?\atname\a is the name of a type name given to each \aname\a.]"
 "[Z]#?[n?Zero fill. If \an\a is given it represents the field width.]"
+"[D?Modifies variables using a dynamic local scope in functions.]"
+"[P?Modifies variables using a static local scope in functions.]"
 "\n"
 "\n[name[=value]...]\n"
 " -f [-tu] [name...]\n"
@@ -2075,7 +2085,7 @@ const char sh_optunset[] =
  "or an error occurred.]"
 "}"
 
-"[+SEE ALSO?\btypeset\b(1)]"
+"[+SEE ALSO?\btypeset\b(1), \blocal\b(1)]"
 ;
 
 const char sh_optunalias[] =