avoid compiler crash when using char literal in str initialization

fix compiler crash when using str var in an expression without &

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

@@ -3,6 +3,7 @@ package prog8.compiler.astprocessing
 import prog8.ast.IStatementContainer
 import prog8.ast.Node
 import prog8.ast.Program
+import prog8.ast.expressions.BinaryExpression
 import prog8.ast.expressions.CharLiteral
 import prog8.ast.expressions.IdentifierReference
 import prog8.ast.expressions.NumericLiteral
@@ -82,6 +83,18 @@ internal fun Program.charLiteralsToUByteLiterals(target: ICompilationTarget, err
             }
             return noModifications
         }
+
+        override fun after(decl: VarDecl, parent: Node): Iterable<IAstModification> {
+            if(decl.datatype.isString) {
+                val initvalue = decl.value
+                if(initvalue!=null && initvalue is BinaryExpression) {
+                    if(initvalue.left is CharLiteral || initvalue.right is CharLiteral) {
+                        errors.err("using a char literal in a string initialization expression, should probably be a string literal with one character in it instead", initvalue.position)
+                    }
+                }
+            }
+            return noModifications
+        }
     }
 
     walker.visit(this)

compiler/test/ast/TestAstChecks.kt

@@ -368,4 +368,19 @@ main {
         errors.warnings.size shouldBe 0
         errors.errors[0] shouldContain "requires integer or boolean type"
     }
+
+    test("missing address of in expression operand") {
+        val src="""
+main {
+    sub start() {
+        str name = "foo"
+        cx16.r0 =  name+2
+    }
+}"""
+        val errors = ErrorReporterForTests()
+        compileText(C64Target(), false, src, writeAssembly = false, errors = errors) shouldBe null
+        errors.errors.size shouldBe 1
+        errors.warnings.size shouldBe 0
+        errors.errors[0] shouldContain "missing &"
+    }
 })

compilerAst/src/prog8/ast/expressions/AstExpressions.kt

@@ -253,7 +253,7 @@ class BinaryExpression(
 
             // if left or right is a numeric literal, and its value fits in the type of the other operand, use the other's operand type
             // EXCEPTION: if the numeric value is a word and the other operand is a byte type (to allow   v * $0008  for example)
-            if (left is NumericLiteral) {
+            if (left is NumericLiteral && rightDt.isNumericOrBool) {
                 if(!(leftDt.isWord && rightDt.isByte)) {
                     val optimal = NumericLiteral.optimalNumeric(rightDt.base, null, left.number, left.position)
                     if (optimal.type != leftDt.base && DataType.forDt(optimal.type) isAssignableTo rightDt) {
@@ -261,7 +261,7 @@ class BinaryExpression(
                     }
                 }
             }
-            if (right is NumericLiteral) {
+            if (right is NumericLiteral && leftDt.isNumericOrBool) {
                 if(!(rightDt.isWord && leftDt.isByte)) {
                     val optimal = NumericLiteral.optimalNumeric(leftDt.base, null, right.number, right.position)
                     if (optimal.type != rightDt.base && DataType.forDt(optimal.type) isAssignableTo leftDt) {

docs/source/todo.rst

@@ -22,6 +22,8 @@ Future Things and Ideas
   Make up our mind! Maybe all setup does need to be put into start() ? because the program cannot function correctly when the variables aren't initialized properly bss is not cleared etc. etc.
   Add a -library $xxxx command line option (and/or some directive) to preselect every setting that is required to make a library at $xxxx rather than a normal loadable and runnable program?
   Need to add some way to generate a stable jump table at a given address.
+  Need library to not call init_system AND init_system_phase2 not either.
+  Library must not include prog8_program_start stuff either.
 - Fix missing cases where regular & has to return the start of the split array in memory whatever byte comes first. Search TODO("address of split word array")
 - Add a syntax to access specific bits in a variable, to avoid manually shifts&ands, something like  variable[4:8] ?  (or something else this may be too similar to regular array indexing)
 - something to reduce the need to use fully qualified names all the time. 'with' ?  Or 'using <prefix>'?

examples/test.p8

@@ -1,8 +1,7 @@
 main {
     sub start() {
-        uword[] tasklist = [1111,2222,3333]
+        ;str test = '?' * 10
-        uword task_address = tasklist[0]
+        str name = "foo"
-        goto task_address
+        cx16.r0 =  name+2
-        goto task_address+1
     }
 }