fix pointer[i].field compiler crash

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

@@ -1624,28 +1624,62 @@ internal class ExpressionGen(private val codeGen: IRCodeGen) {
         val right = binExpr.right as? PtIdentifier
         require(binExpr.operator=="." && left!=null && right!=null) {"invalid dereference expression ${binExpr.position}"}
         val result = mutableListOf<IRCodeChunkBase>()
+        val field: Pair<DataType, UInt>
+        val pointerReg: Int
+        var extraFieldOffset = 0
+
+        if(left.type.isStructInstance) {
+
+            // indexing on a pointer directly
+            // fetch pointer address, determine struct and field, add index * structsize
+            if(left.variable!=null) {
+                val pointerTr = translateExpression(left.variable!!)
+                result += pointerTr.chunks
+                pointerReg = pointerTr.resultReg
+            } else if(left.pointerderef!=null) {
+                TODO("get pointer from deref $left")
+            } else {
+                throw AssemblyError("weird arrayindexer $left")
+            }
+            val struct = left.type.subType!! as StStruct
+            val constindex = left.index as? PtNumber
+            if(constindex!=null) {
+                extraFieldOffset = struct.size.toInt() * constindex.number.toInt()
+            } else {
+                val (chunks, indexReg) = codeGen.loadIndexReg(left.index, struct.size.toInt(), true, false)
+                result += chunks
+                addInstr(result, IRInstruction(Opcode.ADDR, IRDataType.WORD, reg1 = pointerReg, reg2 = indexReg), null)
+            }
+            field = struct.getField(right.name, codeGen.program.memsizer)
+
+        } else {
+
+            // indexing on an array with pointers
+            // fetch the pointer from the array, determine the struct & field
             val indexedTr = translateExpression(left)
             result += indexedTr.chunks
-        val pointerReg = indexedTr.resultReg
+            pointerReg = indexedTr.resultReg
             val struct = left.type.dereference().subType as? StStruct
             require(indexedTr.dt == IRDataType.WORD && struct != null)
-        val field = struct.getField(right.name, this.codeGen.program.memsizer)
+            field = struct.getField(right.name, codeGen.program.memsizer)
-        val vmDt = irType(field.first)
+        }
+
+        // add field offset to pointer and load the value into the result register
+        val fieldVmDt = irType(field.first)
         var resultFpReg = -1
         var resultReg = -1
-        if(vmDt==IRDataType.FLOAT)
+        if (fieldVmDt == IRDataType.FLOAT)
             resultFpReg = codeGen.registers.next(IRDataType.FLOAT)
         else
-            resultReg = codeGen.registers.next(vmDt)
+            resultReg = codeGen.registers.next(fieldVmDt)
-
         result += IRCodeChunk(null, null).also {
-            it += IRInstruction(Opcode.ADD, IRDataType.WORD, reg1 = pointerReg, immediate = field.second.toInt())
+            it += IRInstruction(Opcode.ADD, IRDataType.WORD, reg1 = pointerReg, immediate = field.second.toInt() + extraFieldOffset)
-            it += if(vmDt==IRDataType.FLOAT)
+            it += if (fieldVmDt == IRDataType.FLOAT)
                 IRInstruction(Opcode.LOADI, IRDataType.FLOAT, fpReg1 = resultFpReg, reg1 = pointerReg)
             else
-                IRInstruction(Opcode.LOADI, vmDt, reg1 = resultReg, reg2 = pointerReg)
+                IRInstruction(Opcode.LOADI, fieldVmDt, reg1 = resultReg, reg2 = pointerReg)
         }
-        return ExpressionCodeResult(result, vmDt, resultReg, resultFpReg)
+        return ExpressionCodeResult(result, fieldVmDt, resultReg, resultFpReg)
     }
 
     internal fun traverseRestOfDerefChainToCalculateFinalAddress(targetPointerDeref: PtPointerDeref, pointerReg: Int): Pair<IRCodeChunks, UInt> {

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

@@ -389,22 +389,6 @@ _after:
                 // this will be further modified elsewhere
                 val ident = IdentifierReference(right.chain, right.position)
                 return listOf(IAstModification.ReplaceNode(expr.right, ident, expr))
-
-                // TODO hmmm , replace cx16.r1 = listarray[2]^^.value   with   a temp pointer var to contain the indexed value
-//                val assign = expr.parent as? Assignment
-//                if(assign!=null) {
-//                    val ptrDt = expr.left.inferType(program).getOrUndef()
-//                    val pointerVar = VarDecl.createAuto(ptrDt)
-//                    val pointerIdent = IdentifierReference(pointerVar.name.split("."), expr.position)
-//                    val tgt = AssignTarget(pointerIdent, null, null, null, false, null, position = expr.position)
-//                    val assignPtr = Assignment(tgt, expr.left, AssignmentOrigin.USERCODE, expr.position)
-//                    val derefValue = PtrDereference(pointerIdent.nameInSource + right.chain, false, expr.position)
-//                    return listOf(
-//                        IAstModification.InsertBefore(assign, assignPtr, assign.parent as IStatementContainer),
-//                        IAstModification.ReplaceNode(assign.value, derefValue, assign),
-//                        IAstModification.InsertFirst(pointerVar, expr.definingSubroutine!!)
-//                    )
-//                }
             }
         }
 

docs/source/todo.rst

@@ -1,7 +1,6 @@
 TODO
 ====
 
-fix ^^Node nodes  /  cx16.r0L = nodes[2].weight    compiler crash
 disallow ^^str
 
 

examples/test.p8

@@ -1,12 +1,55 @@
+%import textio
+
 main {
     struct Node {
+        ^^Node next
         ubyte weight
     }
-    ^^Node nodes
+    ^^Node nodes = 2000
 
     sub start() {
-        cx16.r0L = nodes[2].weight     ;TODO fix this compiler crash
+        init()
+        cx16.r0L = nodes[2].weight
+        cx16.r1L = thing.things[2].weight
+
+        txt.print_ub(cx16.r0L)
+        txt.spc()
+        txt.print_ub(cx16.r1L)
+        txt.nl()
+
+        cx16.r9L = 3
+        cx16.r0L = nodes[cx16.r9L].weight
+        cx16.r1L = thing.things[cx16.r9L].weight
+
+        txt.print_ub(cx16.r0L)
+        txt.spc()
+        txt.print_ub(cx16.r1L)
+        txt.nl()
     }
+
+    sub init() {
+        sys.memset(2000, 100, 99)
+        sys.memset(3000, 100, 99)
+
+        ; NNW NNW NNW NNW
+        @(2000+2) = 11
+        @(2000+5) = 22
+        @(2000+8) = 33
+        @(2000+11) = 44
+
+        @(3000+2) = 101
+        @(3000+5) = 102
+        @(3000+8) = 103
+        @(3000+11) = 104
+    }
+}
+
+thing {
+    struct Thing {
+        ^^Thing next
+        ubyte weight
+    }
+    ^^Thing things = 3000
 }