shithub: libmujs

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Omit needless setjmp guard over catch block in try/catch statement.

Make the catch opcodes only set the scope chain, and add explicit
try/endtry opcodes for the catch block in try/catch/finally statements.

--- a/jscompile.c

+++ b/jscompile.c

@@ -666,8 +666,14 @@

 			}

 			/* came from catch block */

 			if (prev == node->c) {

-				emit(J, F, OP_ENDCATCH);

-				if (node->d) cstm(J, F, node->d); /* finally */

+				/* ... with finally */

+				if (node->d) {

+					emit(J, F, OP_ENDCATCH);

+					emit(J, F, OP_ENDTRY);

+					cstm(J, F, node->d); /* finally */

+				} else {

+					emit(J, F, OP_ENDCATCH);

+				}

 			}

 			break;

 		}

@@ -693,25 +699,19 @@

 static void ctrycatch(JF, js_Ast *trystm, js_Ast *catchvar, js_Ast *catchstm)

 {

-	int L1, L2, L3;

+	int L1, L2;

 	L1 = jump(J, F, OP_TRY);

 	{

 		/* if we get here, we have caught an exception in the try block */

-		L2 = jump(J, F, OP_CATCH);

-		emitraw(J, F, addstring(J, F, catchvar->string));

-		{

-			/* if we get here, we have caught an exception in the catch block */

-			emit(J, F, OP_THROW); /* rethrow exception */

-		}

-		label(J, F, L2);

+		emitstring(J, F, OP_CATCH, catchvar->string);

 		cstm(J, F, catchstm);

 		emit(J, F, OP_ENDCATCH);

-		L3 = jump(J, F, OP_JUMP); /* skip past the try block */

+		L2 = jump(J, F, OP_JUMP); /* skip past the try block */

 	}

 	label(J, F, L1);

 	cstm(J, F, trystm);

 	emit(J, F, OP_ENDTRY);

-	label(J, F, L3);

+	label(J, F, L2);

 }

 static void ctrycatchfinally(JF, js_Ast *trystm, js_Ast *catchvar, js_Ast *catchstm, js_Ast *finallystm)

@@ -720,8 +720,7 @@

 	L1 = jump(J, F, OP_TRY);

 	{

 		/* if we get here, we have caught an exception in the try block */

-		L2 = jump(J, F, OP_CATCH);

-		emitraw(J, F, addstring(J, F, catchvar->string));

+		L2 = jump(J, F, OP_TRY);

 		{

 			/* if we get here, we have caught an exception in the catch block */

 			cstm(J, F, finallystm); /* inline finally block */

@@ -728,6 +727,7 @@

 			emit(J, F, OP_THROW); /* rethrow exception */

 		}

 		label(J, F, L2);

+		emitstring(J, F, OP_CATCH, catchvar->string);

 		cstm(J, F, catchstm);

 		emit(J, F, OP_ENDCATCH);

 		L3 = jump(J, F, OP_JUMP); /* skip past the try block to the finally block */

--- a/jscompile.h

+++ b/jscompile.h

@@ -89,8 +89,9 @@

 	OP_TRY,		/* -ADDR- /jump/ or -ADDR- <exception> */

 	OP_ENDTRY,

-	OP_CATCH,	/* -ADDR,S- /jump/ or -ADDR,S- <exception> */

+	OP_CATCH,	/* push scope chain with exception variable */

 	OP_ENDCATCH,

+

 	OP_WITH,

 	OP_ENDWITH,

--- a/jsdump.c

+++ b/jsdump.c

@@ -651,6 +651,7 @@

 		case OP_GETPROPS:

 		case OP_SETPROPS:

 		case OP_DELPROPS:

+		case OP_CATCH:

 			pc(' ');

 			ps(F->strtab[*p++]);

 			break;

@@ -664,11 +665,6 @@

 		case OP_TRY:

 			printf(" %d", *p++);

 			break;

-		case OP_CATCH:

-			printf(" %d", *p++);

-			pc(' ');

-			ps(F->strtab[*p++]);

-			break;

 		}

 		nl();

@@ -713,6 +709,7 @@

 		case JS_CNUMBER: printf("[Number %g]", v.u.object->u.number); break;

 		case JS_CSTRING: printf("[String'%s']", v.u.object->u.string); break;

 		case JS_CERROR: printf("[Error %s]", v.u.object->u.string); break;

+		case JS_CITERATOR: printf("[Iterator %p]", v.u.object); break;

 		default: printf("[Object %p]", v.u.object); break;

 		}

 		break;

--- a/jsrun.c

+++ b/jsrun.c

@@ -822,23 +822,16 @@

 			break;

 		case OP_CATCH:

-			offset = *pc++;

 			str = ST[*pc++];

-			if (js_trypc(J, pc)) {

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

-			} else {

-				obj = jsV_newobject(J, JS_COBJECT, NULL);

-				js_pushobject(J, obj);

-				js_rot2(J);

-				js_setproperty(J, -2, str);

-				J->E = jsR_newenvironment(J, obj, J->E);

-				js_pop(J, 1);

-				pc = pcstart + offset;

-			}

+			obj = jsV_newobject(J, JS_COBJECT, NULL);

+			js_pushobject(J, obj);

+			js_rot2(J);

+			js_setproperty(J, -2, str);

+			J->E = jsR_newenvironment(J, obj, J->E);

+			js_pop(J, 1);

 			break;

 		case OP_ENDCATCH:

-			js_endtry(J);

 			J->E = J->E->outer;

 			break;