From d665489054fd0517d8489bce1da71834a56be956 Mon Sep 17 00:00:00 2001
From: Irmen de Jong <irmen@razorvine.net>
Date: Tue, 2 Jun 2020 00:31:56 +0200
Subject: [PATCH] implemented asm for addressof-assignment

---
 compiler/src/prog8/ast/base/Extensions.kt     |  2 +-
 .../BeforeAsmGenerationAstChanger.kt          | 22 ++++++++++++++-----
 .../target/c64/codegen/AssignmentAsmGen.kt    | 12 +++++-----
 3 files changed, 22 insertions(+), 14 deletions(-)
 rename compiler/src/prog8/compiler/{target => }/BeforeAsmGenerationAstChanger.kt (87%)

diff --git a/compiler/src/prog8/ast/base/Extensions.kt b/compiler/src/prog8/ast/base/Extensions.kt
index 6b61c56d1..e5b3afebd 100644
--- a/compiler/src/prog8/ast/base/Extensions.kt
+++ b/compiler/src/prog8/ast/base/Extensions.kt
@@ -4,7 +4,7 @@ import prog8.ast.Module
 import prog8.ast.Program
 import prog8.ast.processing.*
 import prog8.compiler.CompilationOptions
-import prog8.compiler.target.BeforeAsmGenerationAstChanger
+import prog8.compiler.BeforeAsmGenerationAstChanger
 import prog8.optimizer.FlattenAnonymousScopesAndNopRemover
 
 
diff --git a/compiler/src/prog8/compiler/target/BeforeAsmGenerationAstChanger.kt b/compiler/src/prog8/compiler/BeforeAsmGenerationAstChanger.kt
similarity index 87%
rename from compiler/src/prog8/compiler/target/BeforeAsmGenerationAstChanger.kt
rename to compiler/src/prog8/compiler/BeforeAsmGenerationAstChanger.kt
index c0113adf8..5bd417ffa 100644
--- a/compiler/src/prog8/compiler/target/BeforeAsmGenerationAstChanger.kt
+++ b/compiler/src/prog8/compiler/BeforeAsmGenerationAstChanger.kt
@@ -1,18 +1,15 @@
-package prog8.compiler.target
+package prog8.compiler
 
 import prog8.ast.Node
 import prog8.ast.Program
 import prog8.ast.base.*
-import prog8.ast.expressions.BinaryExpression
-import prog8.ast.expressions.Expression
-import prog8.ast.expressions.IdentifierReference
-import prog8.ast.expressions.TypecastExpression
+import prog8.ast.expressions.*
 import prog8.ast.processing.AstWalker
 import prog8.ast.processing.IAstModification
 import prog8.ast.statements.*
 
 
-class BeforeAsmGenerationAstChanger(val program: Program, val errors: ErrorReporter) : AstWalker() {
+internal class BeforeAsmGenerationAstChanger(val program: Program, val errors: ErrorReporter) : AstWalker() {
 
     override fun after(decl: VarDecl, parent: Node): Iterable<IAstModification> {
         if (decl.value == null && decl.type == VarDeclType.VAR && decl.datatype in NumericDatatypes) {
@@ -101,6 +98,7 @@ class BeforeAsmGenerationAstChanger(val program: Program, val errors: ErrorRepor
     override fun after(typecast: TypecastExpression, parent: Node): Iterable<IAstModification> {
         // see if we can remove superfluous typecasts (outside of expressions)
         // such as casting byte<->ubyte,  word<->uword
+        // Also the special typecast of a reference type (str, array) to an UWORD will be changed into address-of.
         val sourceDt = typecast.expression.inferType(program).typeOrElse(DataType.STRUCT)
         if (typecast.type in ByteDatatypes && sourceDt in ByteDatatypes
                 || typecast.type in WordDatatypes && sourceDt in WordDatatypes) {
@@ -108,6 +106,18 @@ class BeforeAsmGenerationAstChanger(val program: Program, val errors: ErrorRepor
                 return listOf(IAstModification.ReplaceNode(typecast, typecast.expression, parent))
             }
         }
+        else if(sourceDt in PassByReferenceDatatypes) {
+            if(typecast.type==DataType.UWORD) {
+                return listOf(IAstModification.ReplaceNode(
+                        typecast,
+                        AddressOf(typecast.expression as IdentifierReference, typecast.position),
+                        parent
+                ))
+            } else {
+                errors.err("cannot cast pass-by-reference value to type ${typecast.type} (only to UWORD)", typecast.position)
+            }
+        }
+
         return emptyList()
     }
 }
diff --git a/compiler/src/prog8/compiler/target/c64/codegen/AssignmentAsmGen.kt b/compiler/src/prog8/compiler/target/c64/codegen/AssignmentAsmGen.kt
index 608696261..374f0106b 100644
--- a/compiler/src/prog8/compiler/target/c64/codegen/AssignmentAsmGen.kt
+++ b/compiler/src/prog8/compiler/target/c64/codegen/AssignmentAsmGen.kt
@@ -580,9 +580,7 @@ internal class AssignmentAsmGen(private val program: Program, private val errors
                 // non-const value
                 // !!! DON'T FORGET :  CAN BE AUGMENTED ASSIGNMENT !!!
                 when (assign.value) {
-                    is RegisterExpr -> {
-                        TODO("$assign")
-                    }
+                    is RegisterExpr -> throw AssemblyError("expected a typecast for assigning register to word")
                     is IdentifierReference -> {
                         val sourceName = asmgen.asmIdentifierName(assign.value as IdentifierReference)
                         when (assign.aug_op) {
@@ -624,11 +622,11 @@ internal class AssignmentAsmGen(private val program: Program, private val errors
                         }
                         return true
                     }
-                    is DirectMemoryRead -> {
-                        TODO("$assign")
-                    }
+                    is DirectMemoryRead -> throw AssemblyError("expected a typecast for assigning memory read byte to word")
                     is AddressOf -> {
-                        TODO("$assign")
+                        val name = asmgen.asmIdentifierName((assign.value as AddressOf).identifier)
+                        asmgen.out(" lda  #<$name |  sta  $targetName |  lda  #>$name |  sta  $targetName+1")
+                        return true
                     }
                     is ArrayIndexedExpression -> {
                         if (assign.aug_op == "setvalue") {