fix detection of string comparisons (make it aware of new pointer types equivalent to STR)

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

@@ -295,11 +295,25 @@ _after:
     }
 
     override fun after(expr: BinaryExpression, parent: Node): Iterable<IAstModification> {
-        fun isStringComparison(leftDt: InferredTypes.InferredType, rightDt: InferredTypes.InferredType): Boolean =
-            if(leftDt issimpletype BaseDataType.STR && rightDt issimpletype BaseDataType.STR)
-                true
-            else
-                leftDt issimpletype BaseDataType.UWORD && rightDt issimpletype BaseDataType.STR || leftDt issimpletype BaseDataType.STR && rightDt issimpletype BaseDataType.UWORD
+        fun isStringComparison(leftDt: InferredTypes.InferredType, rightDt: InferredTypes.InferredType): Boolean {
+            if (leftDt issimpletype BaseDataType.STR && rightDt issimpletype BaseDataType.STR)
+                return true
+            if (leftDt issimpletype BaseDataType.UWORD && rightDt issimpletype BaseDataType.STR || leftDt issimpletype BaseDataType.STR && rightDt issimpletype BaseDataType.UWORD)
+                return true
+            if(leftDt.isPointer && leftDt.getOrUndef().sub==BaseDataType.UBYTE) {
+                return if(rightDt issimpletype BaseDataType.STR || rightDt.issimpletype(BaseDataType.UWORD))
+                    true
+                else
+                    rightDt.isPointer && rightDt.getOrUndef().sub==BaseDataType.UBYTE
+            }
+            if(rightDt.isPointer && rightDt.getOrUndef().sub==BaseDataType.UBYTE) {
+                return if(leftDt issimpletype BaseDataType.STR || leftDt.issimpletype(BaseDataType.UWORD))
+                    true
+                else
+                    leftDt.isPointer && leftDt.getOrUndef().sub==BaseDataType.UBYTE
+            }
+            return false
+        }
 
         if(expr.operator=="in") {
             val containment = ContainmentCheck(expr.left, expr.right, expr.position)

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

@@ -104,6 +104,9 @@ internal class VerifyFunctionArgTypes(val program: Program, val options: Compila
             if(paramDt.isUnsignedWord && argDt.isPointer)
                 return true
 
+            if(paramDt.isString && (argDt.isPointer && argDt.sub==BaseDataType.UBYTE))
+                return true
+
             return false
         }
 

compiler/test/TestPointers.kt

@@ -491,7 +491,6 @@ main {
         val result = compileText(VMTarget(), false, src, outputDir, writeAssembly = false)!!
         val main = result.compilerAst.allBlocks.first {it.name=="main"}
         val st = main.statements.filterIsInstance<Subroutine>().first {it.name=="start"}.statements
-        st.size shouldBe 8
 
         fun assertIsStringCompare(expr: BinaryExpression) {
             expr.operator shouldBe "=="
@@ -499,6 +498,7 @@ main {
             (expr.left as FunctionCallExpression).target.nameInSource shouldBe listOf("prog8_lib_stringcompare")
         }
 
+        st.size shouldBe 9
         val av1 = (st[0] as Assignment).value as BinaryExpression
         val av2 = (st[1] as Assignment).value as BinaryExpression
         val av3 = (st[2] as Assignment).value as BinaryExpression

docs/source/todo.rst

@@ -1,9 +1,6 @@
 TODO
 ====
 
-fix pointer arith type error (shell fails to compile)  if diskio.list_filename==filename  where filename is a str parameter
-
-
 STRUCTS and TYPED POINTERS (6502 codegen specific)
 --------------------------------------------------