ir: fix overwriting chunk label

codeGenIntermediate/src/prog8/codegen/intermediate/IRCodeGen.kt

@@ -346,8 +346,14 @@ class IRCodeGen(
 
     private fun labelFirstChunk(chunks: IRCodeChunks, label: String): IRCodeChunks {
         require(chunks.isNotEmpty() && label.isNotBlank())
-        val newChunks = chunks.drop(1).toMutableList()
-        val labeledFirstChunk = when(val first=chunks[0]) {
+        val first = chunks[0]
+        if(first.label!=null) {
+            if(first.label==label)
+                return chunks
+            val newFirst = IRCodeChunk(label, first.position, first)
+            return listOf(newFirst) + chunks
+        }
+        val labeledFirstChunk = when(first) {
             is IRCodeChunk -> {
                 val newChunk = IRCodeChunk(label, first.position, first.next)
                 newChunk.instructions += first.instructions
@@ -363,8 +369,7 @@ class IRCodeGen(
                 throw AssemblyError("invalid chunk")
             }
         }
-        newChunks.add(0, labeledFirstChunk)
-        return newChunks
+        return listOf(labeledFirstChunk) + chunks.drop(1)
     }
 
     private fun translate(whenStmt: PtWhen): IRCodeChunks {

compiler/test/vm/TestCompilerVirtual.kt

@@ -99,19 +99,16 @@ mylabel2:
             goto mylabel2
         } until cx16.r0
 
-; TODO fix this for vm codegen:
         repeat cx16.r0 {
 mylabel3:
             goto mylabel3
         }
 
-; TODO fix this for vm codegen:
         for cx16.r0L in 0 to 2 {
 mylabel4:
             goto mylabel4
         }
 
-; TODO fix this for vm codegen:
         for cx16.r0L in cx16.r1L to cx16.r2L {
 mylabel5:
             goto mylabel5

docs/source/todo.rst

@@ -3,7 +3,6 @@ TODO
 
 For next release
 ^^^^^^^^^^^^^^^^
-- ir: fix unit tests
 - ir: join more codechunks, before ir is written to file
 - ir: fix removeWeirdBranches in IR optimizer
 - update diagram in technical.rst?