fix subroutine inline problem with strings

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

@@ -16,7 +16,7 @@ class IRUnusedCodeRemover(
         irprog.blocks.reversed().forEach { block ->
             if(block.isEmpty()) {
                 irprog.blocks.remove(block)
-                irprog.st.removeTree(block.label)
+                pruneSymboltable(block.label)
                 numRemoved++
             }
         }
@@ -24,6 +24,22 @@ class IRUnusedCodeRemover(
         return numRemoved
     }
 
+    private fun pruneSymboltable(blockLabel: String) {
+        // we could clean up the SymbolTable as well, but ONLY if these symbols aren't referenced somewhere still in an instruction
+        val prefix = "$blockLabel."
+        val blockVars = irprog.st.allVariables().filter { it.name.startsWith(prefix) }
+        blockVars.forEach { stVar ->
+            irprog. allSubs().flatMap { it.chunks }.forEach { chunk ->
+                chunk.instructions.forEach { ins ->
+                    if(ins.labelSymbol == stVar.name) {
+                        return
+                    }
+                }
+            }
+        }
+        irprog.st.removeTree(blockLabel)
+    }
+
     private fun removeUnusedSubroutines(): Int {
         val allLabeledChunks = mutableMapOf<String, IRCodeChunkBase>()
         irprog.foreachCodeChunk { chunk ->

codeOptimizers/src/prog8/optimizer/UnusedCodeRemover.kt

@@ -75,7 +75,9 @@ class UnusedCodeRemover(private val program: Program,
                     if(!block.statements.any { it is Subroutine && it.hasBeenInlined })
                         errors.warn("removing unused block '${block.name}'", block.position)
                 }
-                program.removeInternedStringsFromRemovedBlock(block)
+                if(!block.statements.any { it is Subroutine && it.hasBeenInlined }) {
+                    program.removeInternedStringsFromRemovedBlock(block)
+                }
                 return listOf(IAstModification.Remove(block, parent as IStatementContainer))
             }
         }

compiler/test/codegeneration/TestVariousCodeGen.kt

@@ -178,4 +178,28 @@ main {
 }"""
         compileText(C64Target(), false, src, writeAssembly = true) shouldNotBe null
     }
+
+    test("string vars in inlined subroutines are ok") {
+        val src="""
+main {
+    sub start() {
+        void block2.curdir()
+        void block2.other()
+    }
+}
+
+block2 {
+    str result="zzzz"
+    sub curdir() -> str {
+        return result
+    }
+
+    sub other() -> str {
+        return "other"
+    }
+}"""
+
+        compileText(C64Target(), true, src, writeAssembly = true) shouldNotBe null
+        compileText(VMTarget(), true, src, writeAssembly = true) shouldNotBe null
+    }
 })

docs/source/todo.rst

@@ -1,10 +1,6 @@
 TODO
 ====
 
-- fix undefined symbol error for     sub curdir() -> str {  return "todo" }
-- fix placeholder error for
-    str result = "todo"  ,   sub curdir() -> str { return result }
-
 - document some library modules better (diskio, etc)
 
 ...