remove unused interned strings in the resulting code (for example from removed if/else blocks)

compiler/res/prog8lib/cx16/gfx2.p8

@@ -627,7 +627,7 @@ gfx2 {
         ; Non-recursive scanline flood fill.
         ; based loosely on code found here https://www.codeproject.com/Articles/6017/QuickFill-An-efficient-flood-fill-algorithm
         ; with the fixes applied to the seedfill_4 routine as mentioned in the comments.
-        const ubyte MAXDEPTH = 48
+        const ubyte MAXDEPTH = 64
         word @zp xx = x as word
         word @zp yy = y as word
         word[MAXDEPTH] @split @shared stack_xl

compiler/res/prog8lib/cx16/monogfx.p8

@@ -638,7 +638,7 @@ _done
         ; Non-recursive scanline flood fill.
         ; based loosely on code found here https://www.codeproject.com/Articles/6017/QuickFill-An-efficient-flood-fill-algorithm
         ; with the fixes applied to the seedfill_4 routine as mentioned in the comments.
-        const ubyte MAXDEPTH = 48
+        const ubyte MAXDEPTH = 64
         word @zp xx = x as word
         word @zp yy = y as word
         word[MAXDEPTH] @split @shared stack_xl

compiler/res/prog8lib/virtual/monogfx.p8

@@ -373,7 +373,7 @@ monogfx {
         ; Non-recursive scanline flood fill.
         ; based loosely on code found here https://www.codeproject.com/Articles/6017/QuickFill-An-efficient-flood-fill-algorithm
         ; with the fixes applied to the seedfill_4 routine as mentioned in the comments.
-        const ubyte MAXDEPTH = 48
+        const ubyte MAXDEPTH = 64
         word @zp xx = x as word
         word @zp yy = y as word
         word[MAXDEPTH] @split @shared stack_xl

compiler/src/prog8/compiler/astprocessing/VerifyFunctionArgTypes.kt

@@ -19,7 +19,23 @@ internal class VerifyFunctionArgTypes(val program: Program, val errors: IErrorRe
                 errors.err("memory block '${slab.name}' already exists with a different size and/or alignment at ${other.position}", slab.position)
             }
         }
+
+        // remove unused strings from interned strings block
+        val internedBlock = program.allBlocks.singleOrNull { it.name== internedStringsModuleName }
+        internedBlock?.statements?.withIndex()?.reversed()?.forEach { (index, st) ->
+            if(st is VarDecl && st.scopedName !in allStringRefs) {
+                internedBlock.statements.removeAt(index)
             }
+        }
+    }
+
+    override fun visit(identifier: IdentifierReference) {
+        if(identifier.wasStringLiteral(program)) {
+            allStringRefs.add(identifier.nameInSource)
+        }
+    }
+
+    private val allStringRefs = mutableListOf<List<String>>()
 
     private class Slab(val name: String, val size: Int, val align: Int, val position: Position)
     private val memorySlabs = mutableListOf<Slab>()

docs/source/todo.rst

@@ -1,7 +1,7 @@
+
 TODO
 ====
 
-- remove unused interned strings in the resulting code (for example from removed if/else blocks)
 - [on branch: shortcircuit] investigate McCarthy evaluation again? this may also reduce code size perhaps for things like if a>4 or a<2 ....
 - [on branch: ir-less-branch-opcodes] IR: reduce the number of branch instructions such as BEQ, BEQR, etc (gradually), replace with CMP(I) + status branch instruction
 - IR: reduce amount of CMP/CMPI after instructions that set the status bits correctly (LOADs? INC? Bitwise operations, etc), but only after setting the status bits is verified!

examples/test.p8

@@ -1,21 +1,12 @@
 %import textio
-%import string
 %zeropage basicsafe
 
 main {
     sub start() {
-        str name = "irmen????????????"
-        name[5] = 0
-
-        txt.print(name)
-        txt.nl()
-        ubyte length = string.append(name, ".prg")
-
-        txt.print_ub(length)
-        txt.chrout('[')
-        for cx16.r0L in 0 to length-1 {
-            txt.chrout(name[cx16.r0L])
+        if true {
+            txt.print("true")
+        } else {
+            txt.print("false")
         }
-        txt.chrout(']')
     }
 }

gradle.properties

@@ -5,4 +5,4 @@ org.gradle.daemon=true
 kotlin.code.style=official
 javaVersion=11
 kotlinVersion=1.9.20
-version=9.6-SNAPSHOT
+version=9.6

parser/antlr/Prog8ANTLR.g4

@@ -188,8 +188,7 @@ expression :
 
 arrayindexed:
     scoped_identifier arrayindex
-    // TODO to allow chained array indexing:  | arrayindexed arrayindex
-    // TODO or even to allow array indexing on any uword address value:  | expression arrayindex
+    // TODO to allow chained/multidimensional array indexing:  | arrayindexed arrayindex
     ;