fix weird compiler warning for while 1 {..}

codeOptimizers/src/prog8/optimizer/StatementOptimizer.kt

@@ -71,6 +71,11 @@ class StatementOptimizer(private val program: Program,
     }
 
     override fun after(ifElse: IfElse, parent: Node): Iterable<IAstModification> {
+        val constvalue = ifElse.condition.constValue(program)
+        if(constvalue!=null) {
+            errors.warn("condition is always ${constvalue.asBooleanValue}", ifElse.condition.position)
+        }
+
         // remove empty if statements
         if(ifElse.truepart.isEmpty() && ifElse.elsepart.isEmpty())
             return listOf(IAstModification.Remove(ifElse, parent as IStatementContainer))
@@ -87,17 +92,12 @@ class StatementOptimizer(private val program: Program,
             )
         }
 
-        val constvalue = ifElse.condition.constValue(program)
         if(constvalue!=null) {
             return if(constvalue.asBooleanValue){
                 // always true -> keep only if-part
-                if(!ifElse.definingModule.isLibrary)
-                    errors.warn("condition is always true", ifElse.condition.position)
                 listOf(IAstModification.ReplaceNode(ifElse, ifElse.truepart, parent))
             } else {
                 // always false -> keep only else-part
-                if(!ifElse.definingModule.isLibrary)
-                    errors.warn("condition is always false", ifElse.condition.position)
                 listOf(IAstModification.ReplaceNode(ifElse, ifElse.elsepart, parent))
             }
         }

compiler/src/prog8/compiler/astprocessing/CodeDesugarer.kt

@@ -110,6 +110,22 @@ if CONDITION==0
     }
 
     override fun after(whileLoop: WhileLoop, parent: Node): Iterable<IAstModification> {
+        /*
+        while true -> repeat
+        while false -> discard
+         */
+
+        val constCondition = whileLoop.condition.constValue(program)?.asBooleanValue
+        if(constCondition==true) {
+            errors.warn("condition is always true", whileLoop.condition.position)
+            val repeat = RepeatLoop(null, whileLoop.body, whileLoop.position)
+            return listOf(IAstModification.ReplaceNode(whileLoop, repeat, parent))
+        } else if(constCondition==false) {
+            errors.warn("condition is always false", whileLoop.condition.position)
+            return listOf(IAstModification.Remove(whileLoop, parent as IStatementContainer))
+        }
+
+
         /*
 while CONDITION { STUFF }
     ==>

docs/source/todo.rst

@@ -2,6 +2,9 @@
 TODO
 ====
 
+- get rid of jvmTarget in gradle scripts?
+- make  sizeof() works with an asmbinary label
+- should string encodings not be restricted by the compiler target? (at least, ISO should be everywhere?)
 - uword scanline_buf = memory("scanline", 320, 0)   different result when inside a sub or outside a sub??! (imageviewer iff module)
 - [on branch: shortcircuit] investigate McCarthy evaluation again? this may also reduce code size perhaps for things like if a>4 or a<2 ....
 - once VAL_1 is merged into the kernal properly, remove all the workarounds in cx16 floats.parse_f()