5 files changed, 40 insertions, 37 deletions
diff --git a/lparser.c b/lparser.c
index 24668c24..79b2317b 100644
--- a/lparser.c
+++ b/lparser.c
@@ -187,10 +187,10 @@ static int registerlocalvar (LexState *ls, FuncState *fs, TString *varname) {
 /*
-** Create a new local variable with the given 'name'. Return its index
+** Create a new local variable with the given 'name' and given 'kind'.
-** in the function.
+** Return its index in the function.
 */
-static int new_localvar (LexState *ls, TString *name) {
+static int new_localvarkind (LexState *ls, TString *name, int kind) {
  lua_State *L = ls->L;
  FuncState *fs = ls->fs;
  Dyndata *dyd = ls->dyd;
@@ -200,11 +200,19 @@ static int new_localvar (LexState *ls, TString *name) {
  luaM_growvector(L, dyd->actvar.arr, dyd->actvar.n + 1,
                  dyd->actvar.size, Vardesc, USHRT_MAX, "local variables");
  var = &dyd->actvar.arr[dyd->actvar.n++];
-  var->vd.kind = VDKREG;  /* default */
+  var->vd.kind = kind;  /* default */
  var->vd.name = name;
  return dyd->actvar.n - 1 - fs->firstlocal;
 }
+/*
+** Create a new local variable with the given 'name' and regular kind.
+*/
+static int new_localvar (LexState *ls, TString *name) {
+  return new_localvarkind(ls, name, VDKREG);
+}
 #define new_localvarliteral(ls,v) \
    new_localvar(ls,  \
      luaX_newstring(ls, "" v, (sizeof(v)/sizeof(char)) - 1));
@@ -1573,7 +1581,7 @@ static void fornum (LexState *ls, TString *varname, int line) {
  new_localvarliteral(ls, "(for state)");
  new_localvarliteral(ls, "(for state)");
  new_localvarliteral(ls, "(for state)");
-  new_localvar(ls, varname);
+  new_localvarkind(ls, varname, RDKCONST);  /* control variable */
  checknext(ls, '=');
  exp1(ls);  /* initial value */
  checknext(ls, ',');
@@ -1601,8 +1609,8 @@ static void forlist (LexState *ls, TString *indexname) {
  new_localvarliteral(ls, "(for state)");
  new_localvarliteral(ls, "(for state)");
  new_localvarliteral(ls, "(for state)");
-  /* create declared variables */
+  new_localvarkind(ls, indexname, RDKCONST);  /* control variable */
-  new_localvar(ls, indexname);
+  /* other declared variables */
  while (testnext(ls, ',')) {
    new_localvar(ls, str_checkname(ls));
    nvars++;
@@ -1728,14 +1736,14 @@ static void localstat (LexState *ls) {
  FuncState *fs = ls->fs;
  int toclose = -1;  /* index of to-be-closed variable (if any) */
  Vardesc *var;  /* last variable */
-  int vidx, kind;  /* index and kind of last variable */
+  int vidx;  /* index of last variable */
  int nvars = 0;
  int nexps;
  expdesc e;
  do {
-    vidx = new_localvar(ls, str_checkname(ls));
+    TString *vname = str_checkname(ls);
-    kind = getlocalattribute(ls);
+    int kind = getlocalattribute(ls);
-    getlocalvardesc(fs, vidx)->vd.kind = kind;
+    vidx = new_localvarkind(ls, vname, kind);
    if (kind == RDKTOCLOSE) {  /* to-be-closed? */
      if (toclose != -1)  /* one already present? */
        luaK_semerror(ls, "multiple to-be-closed variables in local list");
diff --git a/manual/manual.of b/manual/manual.of
index 416622c1..73d25951 100644
--- a/manual/manual.of
+++ b/manual/manual.of
@@ -1467,7 +1467,7 @@ It has the following syntax:
  exp @bnfter{,} exp @bnfopt{@bnfter{,} exp} @Rw{do} block @Rw{end}}
 }
 The given identifier (@bnfNter{Name}) defines the control variable,
-which is a new variable local to the loop body (@emph{block}).
+which is a new read-only variable local to the loop body (@emph{block}).
 The loop starts by evaluating once the three control expressions.
 Their values are called respectively
@@ -1499,11 +1499,6 @@ For integer loops,
 the control variable never wraps around;
 instead, the loop ends in case of an overflow.
-You should not change the value of the control variable
-during the loop.
-If you need its value after the loop,
-assign it to another variable before exiting the loop.
 }
 @sect4{@title{The generic @Rw{for} loop}
@@ -1526,7 +1521,8 @@ for @rep{var_1}, @Cdots, @rep{var_n} in @rep{explist} do @rep{body} end
 works as follows.
 The names @rep{var_i} declare loop variables local to the loop body.
-The first of these variables is the @emph{control variable}.
+The first of these variables is the @emph{control variable},
+which is a read-only variable.
 The loop starts by evaluating @rep{explist}
 to produce four values:
@@ -1550,9 +1546,6 @@ to-be-closed variable @see{to-be-closed},
 which can be used to release resources when the loop ends.
 Otherwise, it does not interfere with the loop.
-You should not change the value of the control variable
-during the loop.
 }
 }
@@ -9156,6 +9149,9 @@ change between versions.
 @itemize{
 @item{
+The control variable in @Rw{for} loops are read only.
+If you need to change it,
+declare a local variable with the same name in the loop body.
 }
 }
diff --git a/testes/attrib.lua b/testes/attrib.lua
index 83821c06..fc427080 100644
--- a/testes/attrib.lua
+++ b/testes/attrib.lua
@@ -236,7 +236,7 @@ package.path = oldpath
 local fname = "file_does_not_exist2"
 local m, err = pcall(require, fname)
 for t in string.gmatch(package.path..";"..package.cpath, "[^;]+") do
-  t = string.gsub(t, "?", fname)
+  local t = string.gsub(t, "?", fname)
  assert(string.find(err, t, 1, true))
 end
diff --git a/testes/closure.lua b/testes/closure.lua
index c2453677..27ec5596 100644
--- a/testes/closure.lua
+++ b/testes/closure.lua
@@ -60,32 +60,29 @@ end
 -- testing closures with 'for' control variable
 a = {}
 for i=1,10 do
-  a[i] = {set = function(x) i=x end, get = function () return i end}
+  a[i] = function () return i end
  if i == 3 then break end
 end
 assert(a[4] == undef)
-a[1].set(10)
+assert(a[2]() == 2)
-assert(a[2].get() == 2)
+assert(a[3]() == 3)
-a[2].set('a')
-assert(a[3].get() == 3)
-assert(a[2].get() == 'a')
 a = {}
 local t = {"a", "b"}
 for i = 1, #t do
  local k = t[i]
-  a[i] = {set = function(x, y) i=x; k=y end,
+  a[i] = {set = function(x) k=x end,
          get = function () return i, k end}
  if i == 2 then break end
 end
-a[1].set(10, 20)
+a[1].set(10)
 local r,s = a[2].get()
 assert(r == 2 and s == 'b')
 r,s = a[1].get()
-assert(r == 10 and s == 20)
+assert(r == 1 and s == 10)
-a[2].set('a', 'b')
+a[2].set('a')
 r,s = a[2].get()
-assert(r == "a" and s == "b")
+assert(r == 2 and s == "a")
 -- testing closures with 'for' control variable x break
diff --git a/testes/nextvar.lua b/testes/nextvar.lua
index 80b3d05c..87910ef9 100644
--- a/testes/nextvar.lua
+++ b/testes/nextvar.lua
@@ -609,10 +609,12 @@ do
  a = 0; for i=1.0, 0.99999, -1 do a=a+1 end; assert(a==1)
 end
-do   -- changing the control variable
+do   -- attempt to change the control variable
-  local a
+  local st, msg = load "for i = 1, 10 do i = 10 end"
-  a = 0; for i = 1, 10 do a = a + 1; i = "x" end; assert(a == 10)
+  assert(not st and string.find(msg, "assign to const variable 'i'"))
-  a = 0; for i = 10.0, 1, -1 do a = a + 1; i = "x" end; assert(a == 10)
+  local st, msg = load "for v, k in pairs{} do v = 10 end"
+  assert(not st and string.find(msg, "assign to const variable 'v'"))
 end
 -- conversion

diff --git a/lparser.c b/lparser.c index 24668c24..79b2317b 100644 --- a/lparser.c +++ b/lparser.c
@@ -187,10 +187,10 @@ static int registerlocalvar (LexState ls, FuncState fs, TString *varname) {
187		187
188		188
189	/*	189	/*
190	** Create a new local variable with the given 'name'. Return its index	190	** Create a new local variable with the given 'name' and given 'kind'.
191	** in the function.	191	** Return its index in the function.
192	*/	192	*/
193	static int new_localvar (LexState ls, TString name) {	193	static int new_localvarkind (LexState ls, TString name, int kind) {
194	lua_State *L = ls->L;	194	lua_State *L = ls->L;
195	FuncState *fs = ls->fs;	195	FuncState *fs = ls->fs;
196	Dyndata *dyd = ls->dyd;	196	Dyndata *dyd = ls->dyd;
@@ -200,11 +200,19 @@ static int new_localvar (LexState ls, TString name) {
200	luaM_growvector(L, dyd->actvar.arr, dyd->actvar.n + 1,	200	luaM_growvector(L, dyd->actvar.arr, dyd->actvar.n + 1,
201	dyd->actvar.size, Vardesc, USHRT_MAX, "local variables");	201	dyd->actvar.size, Vardesc, USHRT_MAX, "local variables");
202	var = &dyd->actvar.arr[dyd->actvar.n++];	202	var = &dyd->actvar.arr[dyd->actvar.n++];
203	var->vd.kind = VDKREG; /* default */	203	var->vd.kind = kind; /* default */
204	var->vd.name = name;	204	var->vd.name = name;
205	return dyd->actvar.n - 1 - fs->firstlocal;	205	return dyd->actvar.n - 1 - fs->firstlocal;
206	}	206	}
207		207
		208
		209	/*
		210	** Create a new local variable with the given 'name' and regular kind.
		211	*/
		212	static int new_localvar (LexState ls, TString name) {
		213	return new_localvarkind(ls, name, VDKREG);
		214	}
		215
208	#define new_localvarliteral(ls,v) \	216	#define new_localvarliteral(ls,v) \
209	new_localvar(ls, \	217	new_localvar(ls, \
210	luaX_newstring(ls, "" v, (sizeof(v)/sizeof(char)) - 1));	218	luaX_newstring(ls, "" v, (sizeof(v)/sizeof(char)) - 1));
@@ -1573,7 +1581,7 @@ static void fornum (LexState ls, TString varname, int line) {
1573	new_localvarliteral(ls, "(for state)");	1581	new_localvarliteral(ls, "(for state)");
1574	new_localvarliteral(ls, "(for state)");	1582	new_localvarliteral(ls, "(for state)");
1575	new_localvarliteral(ls, "(for state)");	1583	new_localvarliteral(ls, "(for state)");
1576	new_localvar(ls, varname);	1584	new_localvarkind(ls, varname, RDKCONST); /* control variable */
1577	checknext(ls, '=');	1585	checknext(ls, '=');
1578	exp1(ls); /* initial value */	1586	exp1(ls); /* initial value */
1579	checknext(ls, ',');	1587	checknext(ls, ',');
@@ -1601,8 +1609,8 @@ static void forlist (LexState ls, TString indexname) {
1601	new_localvarliteral(ls, "(for state)");	1609	new_localvarliteral(ls, "(for state)");
1602	new_localvarliteral(ls, "(for state)");	1610	new_localvarliteral(ls, "(for state)");
1603	new_localvarliteral(ls, "(for state)");	1611	new_localvarliteral(ls, "(for state)");
1604	/* create declared variables */	1612	new_localvarkind(ls, indexname, RDKCONST); /* control variable */
1605	new_localvar(ls, indexname);	1613	/* other declared variables */
1606	while (testnext(ls, ',')) {	1614	while (testnext(ls, ',')) {
1607	new_localvar(ls, str_checkname(ls));	1615	new_localvar(ls, str_checkname(ls));
1608	nvars++;	1616	nvars++;
@@ -1728,14 +1736,14 @@ static void localstat (LexState *ls) {
1728	FuncState *fs = ls->fs;	1736	FuncState *fs = ls->fs;
1729	int toclose = -1; /* index of to-be-closed variable (if any) */	1737	int toclose = -1; /* index of to-be-closed variable (if any) */
1730	Vardesc var; / last variable */	1738	Vardesc var; / last variable */
1731	int vidx, kind; /* index and kind of last variable */	1739	int vidx; /* index of last variable */
1732	int nvars = 0;	1740	int nvars = 0;
1733	int nexps;	1741	int nexps;
1734	expdesc e;	1742	expdesc e;
1735	do {	1743	do {
1736	vidx = new_localvar(ls, str_checkname(ls));	1744	TString *vname = str_checkname(ls);
1737	kind = getlocalattribute(ls);	1745	int kind = getlocalattribute(ls);
1738	getlocalvardesc(fs, vidx)->vd.kind = kind;	1746	vidx = new_localvarkind(ls, vname, kind);
1739	if (kind == RDKTOCLOSE) { /* to-be-closed? */	1747	if (kind == RDKTOCLOSE) { /* to-be-closed? */
1740	if (toclose != -1) /* one already present? */	1748	if (toclose != -1) /* one already present? */
1741	luaK_semerror(ls, "multiple to-be-closed variables in local list");	1749	luaK_semerror(ls, "multiple to-be-closed variables in local list");


diff --git a/manual/manual.of b/manual/manual.of index 416622c1..73d25951 100644 --- a/manual/manual.of +++ b/manual/manual.of
@@ -1467,7 +1467,7 @@ It has the following syntax:
1467	exp @bnfter{,} exp @bnfopt{@bnfter{,} exp} @Rw{do} block @Rw{end}}	1467	exp @bnfter{,} exp @bnfopt{@bnfter{,} exp} @Rw{do} block @Rw{end}}
1468	}	1468	}
1469	The given identifier (@bnfNter{Name}) defines the control variable,	1469	The given identifier (@bnfNter{Name}) defines the control variable,
1470	which is a new variable local to the loop body (@emph{block}).	1470	which is a new read-only variable local to the loop body (@emph{block}).
1471		1471
1472	The loop starts by evaluating once the three control expressions.	1472	The loop starts by evaluating once the three control expressions.
1473	Their values are called respectively	1473	Their values are called respectively
@@ -1499,11 +1499,6 @@ For integer loops,
1499	the control variable never wraps around;	1499	the control variable never wraps around;
1500	instead, the loop ends in case of an overflow.	1500	instead, the loop ends in case of an overflow.
1501		1501
1502	You should not change the value of the control variable
1503	during the loop.
1504	If you need its value after the loop,
1505	assign it to another variable before exiting the loop.
1506
1507	}	1502	}
1508		1503
1509	@sect4{@title{The generic @Rw{for} loop}	1504	@sect4{@title{The generic @Rw{for} loop}
@@ -1526,7 +1521,8 @@ for @rep{var_1}, @Cdots, @rep{var_n} in @rep{explist} do @rep{body} end
1526	works as follows.	1521	works as follows.
1527		1522
1528	The names @rep{var_i} declare loop variables local to the loop body.	1523	The names @rep{var_i} declare loop variables local to the loop body.
1529	The first of these variables is the @emph{control variable}.	1524	The first of these variables is the @emph{control variable},
		1525	which is a read-only variable.
1530		1526
1531	The loop starts by evaluating @rep{explist}	1527	The loop starts by evaluating @rep{explist}
1532	to produce four values:	1528	to produce four values:
@@ -1550,9 +1546,6 @@ to-be-closed variable @see{to-be-closed},
1550	which can be used to release resources when the loop ends.	1546	which can be used to release resources when the loop ends.
1551	Otherwise, it does not interfere with the loop.	1547	Otherwise, it does not interfere with the loop.
1552		1548
1553	You should not change the value of the control variable
1554	during the loop.
1555
1556	}	1549	}
1557		1550
1558	}	1551	}
@@ -9156,6 +9149,9 @@ change between versions.
9156	@itemize{	9149	@itemize{
9157		9150
9158	@item{	9151	@item{
		9152	The control variable in @Rw{for} loops are read only.
		9153	If you need to change it,
		9154	declare a local variable with the same name in the loop body.
9159	}	9155	}
9160		9156
9161	}	9157	}


diff --git a/testes/attrib.lua b/testes/attrib.lua index 83821c06..fc427080 100644 --- a/testes/attrib.lua +++ b/testes/attrib.lua
@@ -236,7 +236,7 @@ package.path = oldpath
236	local fname = "file_does_not_exist2"	236	local fname = "file_does_not_exist2"
237	local m, err = pcall(require, fname)	237	local m, err = pcall(require, fname)
238	for t in string.gmatch(package.path..";"..package.cpath, "[^;]+") do	238	for t in string.gmatch(package.path..";"..package.cpath, "[^;]+") do
239	t = string.gsub(t, "?", fname)	239	local t = string.gsub(t, "?", fname)
240	assert(string.find(err, t, 1, true))	240	assert(string.find(err, t, 1, true))
241	end	241	end
242		242


diff --git a/testes/closure.lua b/testes/closure.lua index c2453677..27ec5596 100644 --- a/testes/closure.lua +++ b/testes/closure.lua
@@ -60,32 +60,29 @@ end
60	-- testing closures with 'for' control variable	60	-- testing closures with 'for' control variable
61	a = {}	61	a = {}
62	for i=1,10 do	62	for i=1,10 do
63	a[i] = {set = function(x) i=x end, get = function () return i end}	63	a[i] = function () return i end
64	if i == 3 then break end	64	if i == 3 then break end
65	end	65	end
66	assert(a[4] == undef)	66	assert(a[4] == undef)
67	a[1].set(10)	67	assert(a[2]() == 2)
68	assert(a[2].get() == 2)	68	assert(a[3]() == 3)
69	a[2].set('a')
70	assert(a[3].get() == 3)
71	assert(a[2].get() == 'a')
72		69
73	a = {}	70	a = {}
74	local t = {"a", "b"}	71	local t = {"a", "b"}
75	for i = 1, #t do	72	for i = 1, #t do
76	local k = t[i]	73	local k = t[i]
77	a[i] = {set = function(x, y) i=x; k=y end,	74	a[i] = {set = function(x) k=x end,
78	get = function () return i, k end}	75	get = function () return i, k end}
79	if i == 2 then break end	76	if i == 2 then break end
80	end	77	end
81	a[1].set(10, 20)	78	a[1].set(10)
82	local r,s = a[2].get()	79	local r,s = a[2].get()
83	assert(r == 2 and s == 'b')	80	assert(r == 2 and s == 'b')
84	r,s = a[1].get()	81	r,s = a[1].get()
85	assert(r == 10 and s == 20)	82	assert(r == 1 and s == 10)
86	a[2].set('a', 'b')	83	a[2].set('a')
87	r,s = a[2].get()	84	r,s = a[2].get()
88	assert(r == "a" and s == "b")	85	assert(r == 2 and s == "a")
89		86
90		87
91	-- testing closures with 'for' control variable x break	88	-- testing closures with 'for' control variable x break


diff --git a/testes/nextvar.lua b/testes/nextvar.lua index 80b3d05c..87910ef9 100644 --- a/testes/nextvar.lua +++ b/testes/nextvar.lua
@@ -609,10 +609,12 @@ do
609	a = 0; for i=1.0, 0.99999, -1 do a=a+1 end; assert(a==1)	609	a = 0; for i=1.0, 0.99999, -1 do a=a+1 end; assert(a==1)
610	end	610	end
611		611
612	do -- changing the control variable	612	do -- attempt to change the control variable
613	local a	613	local st, msg = load "for i = 1, 10 do i = 10 end"
614	a = 0; for i = 1, 10 do a = a + 1; i = "x" end; assert(a == 10)	614	assert(not st and string.find(msg, "assign to const variable 'i'"))
615	a = 0; for i = 10.0, 1, -1 do a = a + 1; i = "x" end; assert(a == 10)	615
		616	local st, msg = load "for v, k in pairs{} do v = 10 end"
		617	assert(not st and string.find(msg, "assign to const variable 'v'"))
616	end	618	end
617		619
618	-- conversion	620	-- conversion