tweaks for string handling as arguments

compiler/src/prog8/ast/processing/AstChecker.kt

@@ -304,9 +304,9 @@ internal class AstChecker(private val program: Program,
         } else {
             // Pass-by-reference datatypes can not occur as parameters to a subroutine directly
             // Instead, their reference (address) should be passed (as an UWORD).
-            // The language has no typed pointers at this time.
+            // TODO The language has no typed pointers at this time!  This should be handled better.
             if(subroutine.parameters.any{it.type in PassByReferenceDatatypes }) {
-                err("Pass-by-reference types (str, array) cannot occur as a parameter type directly. Instead, use an uword for their address, or access the variable from the outer scope directly.")
+                err("Pass-by-reference types (str, array) cannot occur as a parameter type directly. Instead, use an uword to receive their address, or access the variable from the outer scope directly.")
             }
         }
 

compiler/src/prog8/compiler/target/c64/codegen/AsmGen.kt

@@ -1048,6 +1048,9 @@ $endLabel""")
     fun assignFromWordVariable(target: AssignTarget, variable: IdentifierReference) =
             assignmentAsmGen.assignFromWordVariable(target, variable)
 
+    fun assignFromAddressOf(target: AssignTarget, variable: IdentifierReference) =
+            assignmentAsmGen.assignFromAddressOf(target, variable)
+
     fun assignFromFloatVariable(target: AssignTarget, variable: IdentifierReference) =
             assignmentAsmGen.assignFromFloatVariable(target, variable)
 

compiler/src/prog8/compiler/target/c64/codegen/FunctionCallAsmGen.kt

@@ -115,7 +115,6 @@ internal class FunctionCallAsmGen(private val program: Program, private val asmg
                     in ByteDatatypes -> asmgen.assignFromByteConstant(target, value.number.toShort())
                     in WordDatatypes -> asmgen.assignFromWordConstant(target, value.number.toInt())
                     DataType.FLOAT -> asmgen.assignFromFloatConstant(target, value.number.toDouble())
-                    in PassByReferenceDatatypes -> throw AssemblyError("can't pass string/array as argument via a variable?")    // TODO huh
                     else -> throw AssemblyError("weird parameter datatype")
                 }
             }
@@ -125,7 +124,7 @@ internal class FunctionCallAsmGen(private val program: Program, private val asmg
                     in ByteDatatypes -> asmgen.assignFromByteVariable(target, value)
                     in WordDatatypes -> asmgen.assignFromWordVariable(target, value)
                     DataType.FLOAT -> asmgen.assignFromFloatVariable(target, value)
-                    in PassByReferenceDatatypes -> throw AssemblyError("can't pass string/array as argument via a variable?")     // TODO huh
+                    in PassByReferenceDatatypes -> asmgen.assignFromAddressOf(target, value)
                     else -> throw AssemblyError("weird parameter datatype")
                 }
             }

compiler/src/prog8/optimizer/StatementOptimizer.kt

@@ -105,9 +105,10 @@ internal class StatementOptimizer(private val program: Program,
             }
             if(stringVar!=null) {
                 val vardecl = stringVar.targetVarDecl(program.namespace)!!
-                val string = vardecl.value!! as StringLiteralValue
+                val string = vardecl.value as? StringLiteralValue
+                if(string!=null) {
                     val pos = functionCallStatement.position
-                if(string.value.length==1) {
+                    if (string.value.length == 1) {
                         val firstCharEncoded = CompilationTarget.encodeString(string.value, string.altEncoding)[0]
                         val chrout = FunctionCallStatement(
                                 IdentifierReference(listOf("c64", "CHROUT"), pos),
@@ -115,7 +116,7 @@ internal class StatementOptimizer(private val program: Program,
                                 functionCallStatement.void, pos
                         )
                         return listOf(IAstModification.ReplaceNode(functionCallStatement, chrout, parent))
-                } else if(string.value.length==2) {
+                    } else if (string.value.length == 2) {
                         val firstTwoCharsEncoded = CompilationTarget.encodeString(string.value.take(2), string.altEncoding)
                         val chrout1 = FunctionCallStatement(
                                 IdentifierReference(listOf("c64", "CHROUT"), pos),
@@ -134,6 +135,7 @@ internal class StatementOptimizer(private val program: Program,
                     }
                 }
             }
+        }
 
         // if the first instruction in the called subroutine is a return statement, remove the jump altogeter
         val subroutine = functionCallStatement.target.targetSubroutine(program.namespace)

examples/test.p8

@@ -10,27 +10,15 @@ main {
     float[]  fa = [1,2,3,4]
 
     sub start() {
-        float x = 9.9
+        wot("asdfasdf")
-
+        wot("asdfasdf")
-        fa[2] = 8.8
+        wot("asdfasdf1")
-
-        p()
-
-        ubyte b = 2
-        fa[b] = 9.8
-        p()
-        fa[b] = 9.9
-        p()
-
     }
 
-    sub p() {
+    sub wot(uword text) {
-        byte i
+        ;c64scr.print(text)          ; TODO better type error
-        for i in 0 to len(fa)-1 {
+        ;c64.CHROUT('\n')
-            c64flt.print_f(fa[i])
+        c64scr.print_uwhex(text, 1)
-            c64.CHROUT(',')
-            c64.CHROUT(' ')
-        }
         c64.CHROUT('\n')
     }
 }