enhanced compile_while_expression()/compile_do_while_expression() not to eliminate blocks containing one or more labels

moo/kernel/test-003.moo

@@ -53,7 +53,7 @@ class MyObject(Object)
 	}
 
 
-	method(#class) local_return_001
+	method(#class) test_local_return_001
 	{
 		| a b c d|
 		a := 10.
@@ -70,6 +70,74 @@ class MyObject(Object)
 		^a == 13 and b == 77 and c == 88 and d == 3.
 	}
 
+	method(#class) test_if_001
+	{
+		| a b c d e x |
+
+		x := if (false) { X02: a := 55. goto Z02 }
+		     elif (false) { b := 66.}
+		     elif (2 > 1) { c := 77. goto X02 }
+		     elif (true) { d := 88 }
+		     else { Z02:  e := 99 }.
+
+		^c == 77 and a == 55 and e == 99 and b == nil and d == nil and x == 99.
+	}
+
+	method(#class) test_while_001
+	{
+		| a b i |
+
+		a := 0.
+		b := #(0 0 0 0 0) copy.
+		i := 0.
+
+		while (false)
+		{
+		X02:
+			a := a + 1.
+			b at: i put: 1.
+			i := i + 1.
+			goto X03.
+		}.
+		goto X02.
+
+		until (false)
+		{
+		X03:
+			a := a + 2.
+			b at: i put: 2.
+			i := i + 1.
+			goto Y01.
+		}.
+
+		do
+		{
+		X04:
+			a := a + 3.
+			b at: i put: 3.
+			i := i + 1.
+			goto X05.
+		}
+		while (true).
+	Y01:
+		goto X04.
+
+		do
+		{
+			a := a + 4.
+			b at: i put: 4.
+			i := i + 1.
+			break.
+		X05:
+			a := a + 5.
+			b at: i put: 5.
+			i := i + 1.
+		}
+		until (false).
+
+		^a == 15 and b = #(1 2 3 5 4).
+	}
+
 method(#class) q
 {
 	| v |
@@ -116,13 +184,15 @@ start:
 			[ [] value == nil ],
 			
 			// 20-24
-			[ self local_return_001 ],
+			[ self test_local_return_001 ],
+			[ self test_if_001 ],
+			[ self test_while_001 ],
 			[ (if (1 > 2) { } else { }) == nil. ],
 			[ (if (1 < 2) { } else { }) == nil. ],
 			[ (if (1 > 2) { } else { goto A01. A01: }) == nil ],
-			[ (if (1 > 2) { } else { 9876. goto A02. A02: }) == 9876 ],
 
 			// 25-29
+			[ (if (1 > 2) { } else { 9876. goto A02. A02: }) == 9876 ],
 			[ [ | a3 | a3:= 20. if (a3 == 21) { a3 := 4321. goto L03 } else { a3 := 1234. goto L03 }. a3 := 8888. L03: a3 ] value == 1234 ],
 			[ [ | a4 | a4:= 21. if (a4 == 21) { a4 := 4321. goto L04 } else { a4 := 1234. goto L04 }. a4 := 8888. L04: a4 ] value == 4321 ]
 		).

moo/lib/comp.c

@@ -6462,6 +6462,7 @@ static int compile_while_expression (moo_t* moo) /* or compile_until_expression
 	moo_ioloc_t while_loc, brace_loc, closing_brace_loc;
 	moo_oow_t precondpos, postcondpos, prebbpos, postbbpos;
 	int cond_style = 0, loop_pushed = 0, is_until_loop;
+	moo_label_t* la, * lb;
 
 	MOO_ASSERT (moo, TOKEN_TYPE(moo) == MOO_IOTOK_WHILE || TOKEN_TYPE(moo) == MOO_IOTOK_UNTIL);
 
@@ -6521,12 +6522,14 @@ static int compile_while_expression (moo_t* moo) /* or compile_until_expression
 	GET_TOKEN (moo); /* get { */
 	brace_loc = *TOKEN_LOC(moo);
 	prebbpos = cc->mth.code.len;
+	la = cc->mth._label;
 	if (compile_braced_block(moo) <= -1) goto oops;
+	lb = cc->mth._label;
 	closing_brace_loc = *TOKEN_LOC(moo);
 	GET_TOKEN (moo); /* get the next token after } */
 	postbbpos = cc->mth.code.len;
 
-	if (prebbpos + 1 == postbbpos && cc->mth.code.ptr[prebbpos] == BCODE_PUSH_NIL)
+	if (la == lb && prebbpos + 1 == postbbpos && cc->mth.code.ptr[prebbpos] == BCODE_PUSH_NIL)
 	{
 		/* optimization -
 		 *  the braced block is kind of empty as it only pushes nil.
@@ -6560,7 +6563,7 @@ static int compile_while_expression (moo_t* moo) /* or compile_until_expression
 		}
 	}
 
-	if (cond_style == -1) 
+	if (la == lb && cond_style == -1) 
 	{
 		/* optimization - get rid of instructions generated for the while
 		 * loop including the conditional as the condition was false */
@@ -6591,6 +6594,7 @@ static int compile_do_while_expression (moo_t* moo)
 	moo_oow_t precondpos, postcondpos, prebbpos, postbbpos;
 	int jbinst = 0, loop_pushed = 0, is_until_loop;
 	moo_loop_t* loop = MOO_NULL;
+	moo_label_t* la, * lb;
 
 	MOO_ASSERT (moo, TOKEN_TYPE(moo) == MOO_IOTOK_DO);
 	do_loc = *TOKEN_LOC(moo);
@@ -6603,7 +6607,9 @@ static int compile_do_while_expression (moo_t* moo)
 	if (push_loop(moo, MOO_LOOP_DO_WHILE, prebbpos) <= -1) goto oops;
 	loop_pushed = 1;
 
+	la = cc->mth._label;
 	if (compile_braced_block(moo) <= -1) goto oops;
+	lb = cc->mth._label;
 
 	closing_brace_loc = *TOKEN_LOC(moo);
 	GET_TOKEN (moo); /* get the next token after } */
@@ -6617,7 +6623,7 @@ static int compile_do_while_expression (moo_t* moo)
 	GET_TOKEN (moo); /* get ( */
 	postbbpos = cc->mth.code.len;
 
-	if (prebbpos + 1 == postbbpos && cc->mth.code.ptr[prebbpos] == BCODE_PUSH_NIL)
+	if (la == lb && prebbpos + 1 == postbbpos && cc->mth.code.ptr[prebbpos] == BCODE_PUSH_NIL)
 	{
 		/* optimization -
 		 *  the braced block is kind of empty as it only pushes nil.
@@ -6651,14 +6657,14 @@ static int compile_do_while_expression (moo_t* moo)
 		if (cc->mth.code.ptr[precondpos] == (is_until_loop? BCODE_PUSH_FALSE: BCODE_PUSH_TRUE))
 		{
 			/* the conditional is always true. eliminate PUSH_TRUE and emit an absolute jump */
-			eliminate_instructions (moo, precondpos, cc->mth.code.len - 1);
+			eliminate_instructions (moo, precondpos, precondpos);
 			postcondpos = precondpos;
 			jbinst = BCODE_JUMP_BACKWARD;
 		}
 		else if (cc->mth.code.ptr[precondpos] == (is_until_loop? BCODE_PUSH_TRUE: BCODE_PUSH_FALSE))
 		{
 			/* the conditional is always false. eliminate PUSH_FALSE and don't emit jump */
-			eliminate_instructions (moo, precondpos, cc->mth.code.len - 1);
+			eliminate_instructions (moo, precondpos, precondpos);
 			postcondpos = precondpos;
 			goto skip_emitting_jump_backward;
 		}