shithub: libmujs

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Fix bug where some environment records were not marked by GC.

Environments when calling a function were saved in a local variable.
Therefore the garbage collector did not see them in its list of roots
to follow, resulting in environments being freed while still in use.

--- a/jsgc.c

+++ b/jsgc.c

@@ -120,6 +120,7 @@

 	int nenv = 0, nfun = 0, nobj = 0;

 	int genv = 0, gfun = 0, gobj = 0;

 	int mark;

+	int i;

 	mark = J->gcmark = J->gcmark == 1 ? 2 : 1;

@@ -129,6 +130,8 @@

 	jsG_markobject(J, mark, J->Boolean_prototype);

 	jsG_markobject(J, mark, J->Number_prototype);

 	jsG_markobject(J, mark, J->String_prototype);

+	jsG_markobject(J, mark, J->RegExp_prototype);

+	jsG_markobject(J, mark, J->Date_prototype);

 	jsG_markobject(J, mark, J->Error_prototype);

 	jsG_markobject(J, mark, J->EvalError_prototype);

@@ -142,7 +145,11 @@

 	jsG_markobject(J, mark, J->G);

 	jsG_markstack(J, mark);

+

 	jsG_markenvironment(J, mark, J->E);

+	jsG_markenvironment(J, mark, J->GE);

+	for (i = 0; i < J->envtop; ++i)

+		jsG_markenvironment(J, mark, J->envstack[i]);

 	prevnextenv = &J->gcenv;

 	for (env = J->gcenv; env; env = nextenv) {

--- a/jsi.h

+++ b/jsi.h

@@ -49,6 +49,7 @@

 /* Limits */

 #define JS_STACKSIZE 256	/* value stack size */

+#define JS_ENVLIMIT 64		/* environment stack size */

 #define JS_TRYLIMIT 64		/* exception stack size */

 #define JS_GCLIMIT 10000	/* run gc cycle every N allocations */

@@ -92,6 +93,7 @@

 {

 	jmp_buf buf;

 	js_Environment *E;

+	int envtop;

 	int top, bot;

 	short *pc;

 };

@@ -172,6 +174,10 @@

 	js_Environment *gcenv;

 	js_Function *gcfun;

 	js_Object *gcobj;

+

+	/* environments on the call stack but currently not in scope */

+	int envtop;

+	js_Environment *envstack[JS_ENVLIMIT];

 	/* exception stack */

 	int trylen;

--- a/jsrun.c

+++ b/jsrun.c

@@ -801,16 +801,26 @@

 /* Function calls */

+static void jsR_savescope(js_State *J, js_Environment *newE)

+{

+	if (J->envtop + 1 >= JS_ENVLIMIT)

+		js_stackoverflow(J);

+	J->envstack[J->envtop++] = J->E;

+	J->E = newE;

+}

+

+static void jsR_restorescope(js_State *J)

+{

+	J->E = J->envstack[--J->envtop];

+}

+

 static void jsR_calllwfunction(js_State *J, unsigned int n, js_Function *F, js_Environment *scope)

 {

-	js_Environment *saveE;

 	js_Value v;

 	unsigned int i;

-	saveE = J->E;

+	jsR_savescope(J, scope);

-	J->E = scope;

-

 	if (n > F->numparams) {

 		js_pop(J, F->numparams - n);

 		n = F->numparams;

@@ -823,18 +833,17 @@

 	TOP = --BOT; /* clear stack */

 	js_pushvalue(J, v);

-	J->E = saveE;

+	jsR_restorescope(J);

 }

 static void jsR_callfunction(js_State *J, unsigned int n, js_Function *F, js_Environment *scope)

 {

-	js_Environment *saveE;

 	js_Value v;

 	unsigned int i;

-	saveE = J->E;

+	scope = jsR_newenvironment(J, jsV_newobject(J, JS_COBJECT, NULL), scope);

-	J->E = jsR_newenvironment(J, jsV_newobject(J, JS_COBJECT, NULL), scope);

+	jsR_savescope(J, scope);

 	if (F->arguments) {

 		js_newobject(J);

@@ -866,7 +875,7 @@

 	TOP = --BOT; /* clear stack */

 	js_pushvalue(J, v);

-	J->E = saveE;

+	jsR_restorescope(J);

 }

 static void jsR_callscript(js_State *J, unsigned int n, js_Function *F)

@@ -991,6 +1000,7 @@

 	if (J->trylen == JS_TRYLIMIT)

 		js_error(J, "try: exception stack overflow");

 	J->trybuf[J->trylen].E = J->E;

+	J->trybuf[J->trylen].envtop = J->envtop;

 	J->trybuf[J->trylen].top = J->top;

 	J->trybuf[J->trylen].bot = J->bot;

 	J->trybuf[J->trylen].pc = pc;

@@ -1002,6 +1012,7 @@

 		js_Value v = js_tovalue(J, -1);

 		--J->trylen;

 		J->E = J->trybuf[J->trylen].E;

+		J->envtop = J->trybuf[J->trylen].envtop;

 		J->top = J->trybuf[J->trylen].top;

 		J->bot = J->trybuf[J->trylen].bot;

 		js_pushvalue(J, v);