fix compiler crash with assigning certain array values as vardecl initializer

compiler/src/prog8/compiler/astprocessing/AstExtensions.kt

@@ -23,7 +23,12 @@ internal fun Program.processAstBeforeAsmGeneration(errors: IErrorReporter, compT
 internal fun Program.reorderStatements(errors: IErrorReporter) {
     val reorder = StatementReorderer(this, errors)
     reorder.visit(this)
-    reorder.applyModifications()
+    if(errors.noErrors()) {
+        reorder.applyModifications()
+        reorder.visit(this)
+        if(errors.noErrors())
+            reorder.applyModifications()
+    }
 }
 
 internal fun Program.addTypecasts(errors: IErrorReporter) {

compiler/src/prog8/compiler/astprocessing/StatementReorderer.kt

@@ -210,7 +210,7 @@ internal class StatementReorderer(val program: Program, val errors: IErrorReport
                     val assign = Assignment(target, declValue, decl.position)
                     return listOf(
                             IAstModification.ReplaceNode(decl, assign, parent),
-                            IAstModification.InsertFirst(decl, decl.definingScope())
+                            IAstModification.InsertFirst(decl.copy(), decl.definingScope())
                     )
                 }
             }

compilerAst/src/prog8/ast/statements/AstStatements.kt

@@ -234,9 +234,7 @@ open class VarDecl(val type: VarDeclType,
     }
 
     override fun replaceChildNode(node: Node, replacement: Node) {
-        require(replacement is Expression && node===value)
-        // NOTE: ideally you also want to check that node===value but this sometimes crashes the optimizer when queueing multiple node replacements
-        //       just accept the risk of having the wrong node specified in the IAstModification object...
+        require(replacement is Expression && (value==null || node===value))
         value = replacement
         replacement.parent = this
     }

docs/source/todo.rst

@@ -2,6 +2,8 @@
 TODO
 ====
 
+- optimize %32 to & 31
+
 - optimize several inner loops in gfx2
 - hoist all variable declarations up to the subroutine scope *before* even the constant folding takes place (to avoid undefined symbol errors when referring to a variable from another nested scope in the subroutine)
 - optimize swap of two memread values with index, using the same pointer expression/variable, like swap(@(ptr+1), @(ptr+2))

examples/test.p8

@@ -1,54 +1,12 @@
-%target cx16
-%import textio
-%option no_sysinit
-%zeropage basicsafe
-
-; simple test program for the "VTUI" text user interface library
-; see:  https://github.com/JimmyDansbo/VTUIlib
 
 main {
     sub start() {
-        vtui.initialize()
-        txt.print("ok")
+
+        uword world = $2000
+        ubyte xx
+
+        ubyte chr = world[2]
+        ubyte chr2 = world[xx]
     }
 }
 
-
-vtui $1000 {
-
-    %asmbinary "cx16/vtui/VTUI0.8.BIN", 2     ; skip the 2 dummy load address bytes
-
-    ; NOTE: base address $1000 here must be the same as the block's memory address, for obvious reasons!
-    ; The routines below are for VTUI 0.8
-    romsub $1000  =  initialize() clobbers(A, X, Y)
-    romsub $1002  =  screen_set(ubyte mode @A) clobbers(A, X, Y)
-    romsub $1005  =  set_bank(ubyte bank @Pc) clobbers(A)
-    romsub $1008  =  set_stride(ubyte stride @A) clobbers(A)
-    romsub $100b  =  set_decr(ubyte incrdecr @Pc) clobbers(A)
-    romsub $100e  =  clr_scr(ubyte char @A, ubyte colors @X) clobbers(Y)
-    romsub $1011  =  gotoxy(ubyte column @A, ubyte row @Y)
-    romsub $1014  =  plot_char(ubyte char @A, ubyte colors @X)
-    romsub $1017  =  scan_char() -> ubyte @A, ubyte @X
-    romsub $101a  =  hline(ubyte char @A, ubyte length @Y, ubyte colors @X) clobbers(A)
-    romsub $101d  =  vline(ubyte char @A, ubyte height @Y, ubyte colors @X) clobbers(A)
-    romsub $1020  =  print_str(str txtstring @R0, ubyte length @Y, ubyte colors @X, ubyte convertchars @A) clobbers(A, Y)
-    romsub $1023  =  fill_box(ubyte char @A, ubyte width @R1, ubyte height @R2, ubyte colors @X) clobbers(A, Y)
-    romsub $1026  =  pet2scr(ubyte char @A) -> ubyte @A
-    romsub $1029  =  scr2pet(ubyte char @A) -> ubyte @A
-    romsub $102c  =  border(ubyte mode @A, ubyte width @R1, ubyte height @R2, ubyte colors @X) clobbers(Y)       ; NOTE: mode 6 means 'custom' characters taken from r3 - r6
-    romsub $102f  =  save_rect(ubyte ramtype @A, ubyte vbank @Pc, uword address @R0, ubyte width @R1, ubyte height @R2) clobbers(A, X, Y)
-    romsub $1032  =  rest_rect(ubyte ramtype @A, ubyte vbank @Pc, uword address @R0, ubyte width @R1, ubyte height @R2) clobbers(A, X, Y)
-    romsub $1035  =  input_str(uword buffer @R0, ubyte buflen @Y, ubyte colors @X) clobbers (A) -> ubyte @Y
-
-    ; -- helper function to do string length counting for you internally
-    asmsub print_str2(str txtstring @R0, ubyte colors @X, ubyte convertchars @A) clobbers(A, Y) {
-        %asm {{
-            pha
-            lda  cx16.r0
-            ldy  cx16.r0+1
-            jsr  prog8_lib.strlen
-            pla
-            jmp  print_str
-        }}
-    }
-}