fix multi-var decl

compiler/src/prog8/compiler/astprocessing/AstIdentifiersChecker.kt

@@ -53,16 +53,18 @@ internal class AstIdentifiersChecker(private val errors: IErrorReporter,
         if(decl.name in BuiltinFunctions)
             errors.err("builtin function cannot be redefined", decl.position)
 
-        val existingInSameScope = decl.definingScope.lookup(listOf(decl.name))
-        if(existingInSameScope!=null && existingInSameScope!==decl)
-            nameError(decl.name, decl.position, existingInSameScope)
+        if(decl.names.size<2) {
+            val existingInSameScope = decl.definingScope.lookup(listOf(decl.name))
+            if (existingInSameScope != null && existingInSameScope !== decl)
+                nameError(decl.name, decl.position, existingInSameScope)
 
-        val existingOuter = decl.parent.definingScope.lookup(listOf(decl.name))
-        if (existingOuter != null && existingOuter !== decl && existingOuter is VarDecl) {
-            if(existingOuter.parent!==decl.parent)
-                nameShadowWarning(decl.name, decl.position, existingOuter)
-            else
-                nameError(decl.name, decl.position, existingOuter)
+            val existingOuter = decl.parent.definingScope.lookup(listOf(decl.name))
+            if (existingOuter != null && existingOuter !== decl && existingOuter is VarDecl) {
+                if (existingOuter.parent !== decl.parent)
+                    nameShadowWarning(decl.name, decl.position, existingOuter)
+                else
+                    nameError(decl.name, decl.position, existingOuter)
+            }
         }
 
         if(decl.definingBlock.name==decl.name)

compiler/test/ast/TestVariousCompilerAst.kt

@@ -8,6 +8,7 @@ import io.kotest.matchers.types.instanceOf
 import prog8.ast.IFunctionCall
 import prog8.ast.expressions.*
 import prog8.ast.statements.Assignment
+import prog8.ast.statements.ForLoop
 import prog8.ast.statements.InlineAssembly
 import prog8.ast.statements.VarDecl
 import prog8.code.core.DataType
@@ -390,5 +391,54 @@ main {
 }"""
         compileText(VMTarget(), optimize=false, src, writeAssembly=false) shouldNotBe null
     }
+
+    test("multi-var decls in scope with initializer") {
+        val src="""
+main {
+    sub start() {
+        ubyte w
+
+        for w in 0 to 20 {
+            ubyte @zp x,y,z=13
+            ubyte q,r,s
+            x++
+            y++
+            z++
+        }
+    }
+}"""
+        val result = compileText(VMTarget(), optimize = false, src, writeAssembly = false)!!
+        val st = result.compilerAst.entrypoint.statements
+        /*
+    sub start () {
+        ubyte s
+        s = 0
+        ubyte r
+        r = 0
+        ubyte q
+        q = 0
+        ubyte @zp z
+        ubyte @zp y
+        ubyte @zp x
+        ubyte w
+        for w in 0 to 20 step 1  {
+            z = 13
+            y = 13
+            x = 13
+            x++
+            y++
+            z++
+        }
+    }
+         */
+        val vars = st.filterIsInstance<VarDecl>()
+        vars.size shouldBe 7
+        vars.all { it.names.size<=1 } shouldBe true
+        vars.map { it.name } shouldBe listOf("s","r","q","z","y","x","w")
+        val forloop = st.single { it is ForLoop } as ForLoop
+        forloop.body.statements[0] shouldBe instanceOf<Assignment>()
+        forloop.body.statements[1] shouldBe instanceOf<Assignment>()
+        forloop.body.statements[2] shouldBe instanceOf<Assignment>()
+    }
 })
 

compilerAst/src/prog8/ast/antlr/Antlr2Kotlin.kt

@@ -660,7 +660,7 @@ private fun VardeclContext.toAst(type: VarDeclType, value: Expression?): VarDecl
             zp,
             arrayindex()?.toAst(),
             name,
-            identifiers.map { it.NAME().text },
+            if(identifiers.size==1) emptyList() else identifiers.map { it.NAME().text },
             value,
             ARRAYSIG() != null || arrayindex() != null,
             options.SHARED().isNotEmpty(),