From 23ae5cf5f552ad71b1918433609ad2f83eef2579 Mon Sep 17 00:00:00 2001
From: jespergravgaard <jesper@balmangravgaard.dk>
Date: Thu, 9 Apr 2020 09:21:43 +0200
Subject: [PATCH] Variable extern declarations are now supported. Closes #196

---
 .../java/dk/camelot64/kickc/Compiler.java     |   1 +
 .../kickc/model/VariableBuilder.java          |  38 +-
 .../camelot64/kickc/model/symbols/Scope.java  |  21 +-
 .../kickc/model/symbols/Variable.java         |  11 +
 .../model/types/SymbolTypeConversion.java     |  31 +-
 .../Pass0GenerateStatementSequence.java       |   5 +
 .../passes/Pass1AssertProcedureDefined.java   |   2 +-
 .../passes/Pass1AssertVariableDefined.java    |  23 +
 .../dk/camelot64/kickc/test/TestPrograms.java |  41 +-
 ...ch.kc => cstyle-decl-function-mismatch.kc} |   0
 ...ing.kc => cstyle-decl-function-missing.kc} |   0
 ...c => cstyle-decl-function-redefinition.kc} |   0
 ...tyle-decl-0.kc => cstyle-decl-function.kc} |   0
 src/test/kc/cstyle-decl-var-mismatch.kc       |  28 +
 src/test/kc/cstyle-decl-var-missing.kc        |  22 +
 src/test/kc/cstyle-decl-var-multiple.kc       |  18 +
 src/test/kc/cstyle-decl-var-redefinition.kc   |  23 +
 src/test/kc/cstyle-decl-var.kc                |  23 +
 ...le-decl-0.asm => cstyle-decl-function.asm} |   0
 ...le-decl-0.cfg => cstyle-decl-function.cfg} |   0
 ...le-decl-0.log => cstyle-decl-function.log} |   0
 ...le-decl-0.sym => cstyle-decl-function.sym} |   0
 src/test/ref/cstyle-decl-var-multiple.asm     |  30 +
 src/test/ref/cstyle-decl-var-multiple.cfg     |  33 ++
 src/test/ref/cstyle-decl-var-multiple.log     | 531 ++++++++++++++++++
 src/test/ref/cstyle-decl-var-multiple.sym     |  23 +
 src/test/ref/cstyle-decl-var.asm              |  20 +
 src/test/ref/cstyle-decl-var.cfg              |  19 +
 src/test/ref/cstyle-decl-var.log              | 306 ++++++++++
 src/test/ref/cstyle-decl-var.sym              |   8 +
 30 files changed, 1235 insertions(+), 22 deletions(-)
 create mode 100644 src/main/java/dk/camelot64/kickc/passes/Pass1AssertVariableDefined.java
 rename src/test/kc/{cstyle-decl-mismatch.kc => cstyle-decl-function-mismatch.kc} (100%)
 rename src/test/kc/{cstyle-decl-missing.kc => cstyle-decl-function-missing.kc} (100%)
 rename src/test/kc/{cstyle-decl-redefinition.kc => cstyle-decl-function-redefinition.kc} (100%)
 rename src/test/kc/{cstyle-decl-0.kc => cstyle-decl-function.kc} (100%)
 create mode 100644 src/test/kc/cstyle-decl-var-mismatch.kc
 create mode 100644 src/test/kc/cstyle-decl-var-missing.kc
 create mode 100644 src/test/kc/cstyle-decl-var-multiple.kc
 create mode 100644 src/test/kc/cstyle-decl-var-redefinition.kc
 create mode 100644 src/test/kc/cstyle-decl-var.kc
 rename src/test/ref/{cstyle-decl-0.asm => cstyle-decl-function.asm} (100%)
 rename src/test/ref/{cstyle-decl-0.cfg => cstyle-decl-function.cfg} (100%)
 rename src/test/ref/{cstyle-decl-0.log => cstyle-decl-function.log} (100%)
 rename src/test/ref/{cstyle-decl-0.sym => cstyle-decl-function.sym} (100%)
 create mode 100644 src/test/ref/cstyle-decl-var-multiple.asm
 create mode 100644 src/test/ref/cstyle-decl-var-multiple.cfg
 create mode 100644 src/test/ref/cstyle-decl-var-multiple.log
 create mode 100644 src/test/ref/cstyle-decl-var-multiple.sym
 create mode 100644 src/test/ref/cstyle-decl-var.asm
 create mode 100644 src/test/ref/cstyle-decl-var.cfg
 create mode 100644 src/test/ref/cstyle-decl-var.log
 create mode 100644 src/test/ref/cstyle-decl-var.sym

diff --git a/src/main/java/dk/camelot64/kickc/Compiler.java b/src/main/java/dk/camelot64/kickc/Compiler.java
index 7357dface..6b5114964 100644
--- a/src/main/java/dk/camelot64/kickc/Compiler.java
+++ b/src/main/java/dk/camelot64/kickc/Compiler.java
@@ -199,6 +199,7 @@ public class Compiler {
       new Pass1GenerateControlFlowGraph(program).execute();
       new Pass1ResolveForwardReferences(program).execute();
       new Pass1AssertProcedureDefined(program).execute();
+      new Pass1AssertVariableDefined(program).execute();
       new PassNAssertStructMembers(program).execute();
       new Pass1UnwindBlockScopes(program).execute();
       new Pass1Procedures(program).execute();
diff --git a/src/main/java/dk/camelot64/kickc/model/VariableBuilder.java b/src/main/java/dk/camelot64/kickc/model/VariableBuilder.java
index 255bdebe7..519613359 100644
--- a/src/main/java/dk/camelot64/kickc/model/VariableBuilder.java
+++ b/src/main/java/dk/camelot64/kickc/model/VariableBuilder.java
@@ -2,6 +2,7 @@ package dk.camelot64.kickc.model;
 
 import dk.camelot64.kickc.model.symbols.*;
 import dk.camelot64.kickc.model.types.SymbolType;
+import dk.camelot64.kickc.model.types.SymbolTypeConversion;
 import dk.camelot64.kickc.model.types.SymbolTypePointer;
 import dk.camelot64.kickc.model.types.SymbolTypeStruct;
 import dk.camelot64.kickc.model.values.ScopeRef;
@@ -70,7 +71,34 @@ public class VariableBuilder {
       }
       variable.setMemoryArea(this.getMemoryArea());
       variable.setMemoryAlignment(this.getAlignment());
-      scope.add(variable);
+      variable.setDeclarationOnly(this.isDeclarationOnly());
+
+
+      // Check if the symbol has already been declared
+      Symbol declaredSymbol = scope.getLocalSymbol(varName);
+      if(declaredSymbol!=null &&  !declaredSymbol.getFullName().equals(variable.getFullName()))
+         // We found another symbol!
+         declaredSymbol = null;
+
+      if(declaredSymbol!=null) {
+         if(!(declaredSymbol instanceof Variable))
+            throw new CompileError("Error! Conflicting declarations for: "+variable.getFullName());
+         Variable declaredVar = (Variable) declaredSymbol;
+         if(!declaredVar.isDeclarationOnly() && !variable.isDeclarationOnly())
+            throw new CompileError("Error! Redefinition of variable: "+variable.getFullName());
+         if(!SymbolTypeConversion.variableDeclarationMatch(declaredVar, variable))
+            throw new CompileError("Error! Conflicting declarations for: "+variable.getFullName());
+
+         // Update the variable with the definition
+         if(!variable.isDeclarationOnly()) {
+            scope.remove(declaredSymbol);
+            scope.add(variable);
+         }
+      } else {
+         // Not already declared - add it
+         scope.add(variable);
+      }
+
       return variable;
    }
 
@@ -219,6 +247,14 @@ public class VariableBuilder {
       return hasDirective(Directive.Export.class);
    }
 
+   /**
+    * Declared but not defined. ( "extern" keyword)
+    * @return true if the variable is declared but not defined.
+    */
+   public boolean isDeclarationOnly() {
+      return hasDirective(Directive.Extern.class);
+   }
+
    /**
     * Is the variable single-static-assignment ot multi-assignment.
     * Depends on the type and scope of the variable plus directives directly affecting the memory layout ( __mma, __sa, __zp, __address, __align).
diff --git a/src/main/java/dk/camelot64/kickc/model/symbols/Scope.java b/src/main/java/dk/camelot64/kickc/model/symbols/Scope.java
index 64cdb1a7e..60f0242fa 100644
--- a/src/main/java/dk/camelot64/kickc/model/symbols/Scope.java
+++ b/src/main/java/dk/camelot64/kickc/model/symbols/Scope.java
@@ -1,10 +1,7 @@
 package dk.camelot64.kickc.model.symbols;
 
-import dk.camelot64.kickc.model.CompileError;
 import dk.camelot64.kickc.model.InternalError;
-import dk.camelot64.kickc.model.Program;
-import dk.camelot64.kickc.model.Registers;
-import dk.camelot64.kickc.model.VariableRegisterWeights;
+import dk.camelot64.kickc.model.*;
 import dk.camelot64.kickc.model.types.SymbolType;
 import dk.camelot64.kickc.model.values.*;
 
@@ -102,7 +99,7 @@ public abstract class Scope implements Symbol, Serializable {
 
    public Variable addVariableIntermediate() {
       String name = allocateIntermediateVariableName();
-      return add(Variable.createIntermediate( name, this, getSegmentData()));
+      return add(Variable.createIntermediate(name, this, getSegmentData()));
    }
 
    /**
@@ -169,8 +166,8 @@ public abstract class Scope implements Symbol, Serializable {
 
    public Variable getVariable(String name) {
       Variable symbol = (Variable) getSymbol(name);
-      if(symbol!=null && !symbol.isVariable())
-         throw new InternalError("Symbol is not a variable! "+symbol.toString());
+      if(symbol != null && !symbol.isVariable())
+         throw new InternalError("Symbol is not a variable! " + symbol.toString());
       return symbol;
    }
 
@@ -180,7 +177,8 @@ public abstract class Scope implements Symbol, Serializable {
 
    public Variable getConstant(String name) {
       Variable symbol = (Variable) getSymbol(name);
-      if(symbol!=null && !symbol.isKindConstant()) throw new InternalError("Symbol is not a constant! "+symbol.toString());
+      if(symbol != null && !symbol.isKindConstant())
+         throw new InternalError("Symbol is not a constant! " + symbol.toString());
       return symbol;
    }
 
@@ -190,6 +188,7 @@ public abstract class Scope implements Symbol, Serializable {
 
    /**
     * Get all variables/constants
+    *
     * @param includeSubScopes true to include sub-scopes
     * @return all variables/constants
     */
@@ -209,6 +208,7 @@ public abstract class Scope implements Symbol, Serializable {
 
    /**
     * Get all runtime variables (excluding constants)
+    *
     * @param includeSubScopes true to include sub-scopes
     * @return all runtime variables (excluding constants)
     */
@@ -222,6 +222,7 @@ public abstract class Scope implements Symbol, Serializable {
 
    /**
     * Get all constants
+    *
     * @param includeSubScopes true to include sub-scopes
     * @return all constants
     */
@@ -368,7 +369,7 @@ public abstract class Scope implements Symbol, Serializable {
                res.append(symbol.toString(program));
                if(symVar.isArray()) {
                   res.append("[");
-                  if(symVar.getArraySize()!=null) {
+                  if(symVar.getArraySize() != null) {
                      res.append(symVar.getArraySize().toString(program));
                   }
                   res.append("] ");
@@ -395,7 +396,7 @@ public abstract class Scope implements Symbol, Serializable {
                      }
                   }
                }
-               if(symVar.getInitValue()!=null) {
+               if(symVar.getInitValue() != null) {
                   res.append(" = " + symVar.getInitValue().toString(program));
                }
                res.append("\n");
diff --git a/src/main/java/dk/camelot64/kickc/model/symbols/Variable.java b/src/main/java/dk/camelot64/kickc/model/symbols/Variable.java
index c4443a9d3..041c6a8c9 100644
--- a/src/main/java/dk/camelot64/kickc/model/symbols/Variable.java
+++ b/src/main/java/dk/camelot64/kickc/model/symbols/Variable.java
@@ -112,6 +112,9 @@ public class Variable implements Symbol {
    /** If the variable is assigned to a specific "register", this contains the register. If null the variable has no allocation (yet). Constants are never assigned to registers. [Only variables - not constants and not PHI masters] */
    private Registers.Register allocation;
 
+   /** If the variable is only declared and not defined (using the "extern" keyword). */
+   private boolean isDeclarationOnly;
+
    /**
     * Create a variable (or constant)
     *
@@ -594,6 +597,14 @@ public class Variable implements Symbol {
       return getType() instanceof SymbolTypeStruct && isKindLoadStore();
    }
 
+   public boolean isDeclarationOnly() {
+      return isDeclarationOnly;
+   }
+
+   public void setDeclarationOnly(boolean declarationOnly) {
+      isDeclarationOnly = declarationOnly;
+   }
+
    public List<Comment> getComments() {
       return comments;
    }
diff --git a/src/main/java/dk/camelot64/kickc/model/types/SymbolTypeConversion.java b/src/main/java/dk/camelot64/kickc/model/types/SymbolTypeConversion.java
index 3a5fafccb..fdaaf69c6 100644
--- a/src/main/java/dk/camelot64/kickc/model/types/SymbolTypeConversion.java
+++ b/src/main/java/dk/camelot64/kickc/model/types/SymbolTypeConversion.java
@@ -5,6 +5,7 @@ import dk.camelot64.kickc.model.ConstantNotLiteral;
 import dk.camelot64.kickc.model.statements.Statement;
 import dk.camelot64.kickc.model.symbols.Procedure;
 import dk.camelot64.kickc.model.symbols.ProgramScope;
+import dk.camelot64.kickc.model.symbols.Variable;
 import dk.camelot64.kickc.model.values.ConstantInteger;
 import dk.camelot64.kickc.model.values.ConstantLiteral;
 import dk.camelot64.kickc.model.values.ConstantValue;
@@ -226,8 +227,8 @@ public class SymbolTypeConversion {
          return true;
       }
       if(lValueType instanceof SymbolTypePointer && rValueType instanceof SymbolTypePointer && assignmentTypeMatch(((SymbolTypePointer) lValueType).getElementType(), ((SymbolTypePointer) rValueType).getElementType())) {
-            // Pointer types assigned from each other
-            return true;
+         // Pointer types assigned from each other
+         return true;
       }
       return false;
    }
@@ -250,6 +251,7 @@ public class SymbolTypeConversion {
 
    /**
     * Checks that two procedure declarations are a proper match
+    *
     * @param first The first procedure declaration
     * @param second The first procedure declaration
     * @return true if they match types. False otherwise
@@ -265,4 +267,29 @@ public class SymbolTypeConversion {
    }
 
 
+   /**
+    * Checks that two variable declarations are a proper match
+    *
+    * @param first The first variable declaration
+    * @param second The first variable declaration
+    * @return true if they match types. False otherwise
+    */
+   public static boolean variableDeclarationMatch(Variable first, Variable second) {
+      if(!first.getFullName().equals(second.getFullName()))
+         return false;
+      if(!first.getType().equals(second.getType()))
+         return false;
+      if(first.isNoModify() != second.isNoModify())
+         return false;
+      if(first.isVolatile() != second.isVolatile())
+         return false;
+      if(first.isToNoModify() != second.isToNoModify())
+         return false;
+      if(first.isToVolatile() != second.isToVolatile())
+         return false;
+      if(first.isPermanent() != second.isPermanent())
+         return false;
+      return true;
+   }
+
 }
diff --git a/src/main/java/dk/camelot64/kickc/passes/Pass0GenerateStatementSequence.java b/src/main/java/dk/camelot64/kickc/passes/Pass0GenerateStatementSequence.java
index 59ccb37a9..7c5c5e080 100644
--- a/src/main/java/dk/camelot64/kickc/passes/Pass0GenerateStatementSequence.java
+++ b/src/main/java/dk/camelot64/kickc/passes/Pass0GenerateStatementSequence.java
@@ -1094,6 +1094,11 @@ public class Pass0GenerateStatementSequence extends KickCParserBaseVisitor<Objec
       return new Directive.Static();
    }
 
+   @Override
+   public Object visitDirectiveExtern(KickCParser.DirectiveExternContext ctx) {
+      return new Directive.Extern();
+   }
+
    @Override
    public Directive visitDirectiveExport(KickCParser.DirectiveExportContext ctx) {
       return new Directive.Export();
diff --git a/src/main/java/dk/camelot64/kickc/passes/Pass1AssertProcedureDefined.java b/src/main/java/dk/camelot64/kickc/passes/Pass1AssertProcedureDefined.java
index 96a69692d..79d00952f 100644
--- a/src/main/java/dk/camelot64/kickc/passes/Pass1AssertProcedureDefined.java
+++ b/src/main/java/dk/camelot64/kickc/passes/Pass1AssertProcedureDefined.java
@@ -22,7 +22,7 @@ public class Pass1AssertProcedureDefined extends Pass1Base {
          final Label procedureLabel = procedure.getLabel();
          final ControlFlowBlock procedureBlock = getGraph().getBlock(procedureLabel.getRef());
          if(procedureBlock == null)
-            throw new CompileError("Error! Function is never declared: " + procedure.getFullName());
+            throw new CompileError("Error! Function body is never defined: " + procedure.getFullName());
       }
       return false;
    }
diff --git a/src/main/java/dk/camelot64/kickc/passes/Pass1AssertVariableDefined.java b/src/main/java/dk/camelot64/kickc/passes/Pass1AssertVariableDefined.java
new file mode 100644
index 000000000..6af219cd1
--- /dev/null
+++ b/src/main/java/dk/camelot64/kickc/passes/Pass1AssertVariableDefined.java
@@ -0,0 +1,23 @@
+package dk.camelot64.kickc.passes;
+
+import dk.camelot64.kickc.model.CompileError;
+import dk.camelot64.kickc.model.Program;
+import dk.camelot64.kickc.model.symbols.Variable;
+
+/** Pass that checks that all variables declared have a definition*/
+public class Pass1AssertVariableDefined extends Pass1Base {
+
+   public Pass1AssertVariableDefined(Program program) {
+      super(program);
+   }
+
+   @Override
+   public boolean step() {
+      for(Variable var : getScope().getAllVars(true)) {
+         if(var.isDeclarationOnly())
+            throw new CompileError("Error! Variable is declared but never defined: " +  var.getFullName());
+      }
+      return false;
+   }
+
+}
diff --git a/src/test/java/dk/camelot64/kickc/test/TestPrograms.java b/src/test/java/dk/camelot64/kickc/test/TestPrograms.java
index 460b461b4..5de2caf7a 100644
--- a/src/test/java/dk/camelot64/kickc/test/TestPrograms.java
+++ b/src/test/java/dk/camelot64/kickc/test/TestPrograms.java
@@ -38,23 +38,48 @@ public class TestPrograms {
    }
 
    @Test
-   public void testCStyleDeclMissing() throws IOException, URISyntaxException {
-      assertError("cstyle-decl-missing", "Error! Function is never declared: sum", false);
+   public void testCStyleDeclVarMultiple() throws IOException, URISyntaxException {
+      compileAndCompare("cstyle-decl-var-multiple");
    }
 
    @Test
-   public void testCStyleDeclRedefinition() throws IOException, URISyntaxException {
-      assertError("cstyle-decl-redefinition", "Error! Redefinition of function: sum");
+   public void testCStyleDeclVarMissing() throws IOException, URISyntaxException {
+      assertError("cstyle-decl-var-missing", "Variable is declared but never defined: SCREEN", false);
    }
 
    @Test
-   public void testCStyleDeclMismatch() throws IOException, URISyntaxException {
-      assertError("cstyle-decl-mismatch", "Error! Conflicting declarations for: sum");
+   public void testCStyleDeclVarMismatch() throws IOException, URISyntaxException {
+      assertError("cstyle-decl-var-mismatch", "Error! Conflicting declarations for: SCREEN");
    }
 
    @Test
-   public void testCStyleDecl0() throws IOException, URISyntaxException {
-      compileAndCompare("cstyle-decl-0");
+   public void testCStyleDeclVarRedefinition() throws IOException, URISyntaxException {
+      assertError("cstyle-decl-var-redefinition", "Error! Redefinition of variable: SCREEN");
+   }
+
+   @Test
+   public void testCStyleDeclVar() throws IOException, URISyntaxException {
+      compileAndCompare("cstyle-decl-var");
+   }
+
+   @Test
+   public void testCStyleDeclFunctionMissing() throws IOException, URISyntaxException {
+      assertError("cstyle-decl-function-missing", "Error! Function body is never defined: sum", false);
+   }
+
+   @Test
+   public void testCStyleDeclFunctionRedefinition() throws IOException, URISyntaxException {
+      assertError("cstyle-decl-function-redefinition", "Error! Redefinition of function: sum");
+   }
+
+   @Test
+   public void testCStyleDeclFunctionMismatch() throws IOException, URISyntaxException {
+      assertError("cstyle-decl-function-mismatch", "Error! Conflicting declarations for: sum");
+   }
+
+   @Test
+   public void testCStyleDeclFunction() throws IOException, URISyntaxException {
+      compileAndCompare("cstyle-decl-function");
    }
 
    @Test
diff --git a/src/test/kc/cstyle-decl-mismatch.kc b/src/test/kc/cstyle-decl-function-mismatch.kc
similarity index 100%
rename from src/test/kc/cstyle-decl-mismatch.kc
rename to src/test/kc/cstyle-decl-function-mismatch.kc
diff --git a/src/test/kc/cstyle-decl-missing.kc b/src/test/kc/cstyle-decl-function-missing.kc
similarity index 100%
rename from src/test/kc/cstyle-decl-missing.kc
rename to src/test/kc/cstyle-decl-function-missing.kc
diff --git a/src/test/kc/cstyle-decl-redefinition.kc b/src/test/kc/cstyle-decl-function-redefinition.kc
similarity index 100%
rename from src/test/kc/cstyle-decl-redefinition.kc
rename to src/test/kc/cstyle-decl-function-redefinition.kc
diff --git a/src/test/kc/cstyle-decl-0.kc b/src/test/kc/cstyle-decl-function.kc
similarity index 100%
rename from src/test/kc/cstyle-decl-0.kc
rename to src/test/kc/cstyle-decl-function.kc
diff --git a/src/test/kc/cstyle-decl-var-mismatch.kc b/src/test/kc/cstyle-decl-var-mismatch.kc
new file mode 100644
index 000000000..84556defd
--- /dev/null
+++ b/src/test/kc/cstyle-decl-var-mismatch.kc
@@ -0,0 +1,28 @@
+// Test variable declarations
+// Declaration type mismatch
+
+// An extern with one type
+extern unsigned int SCREEN;
+
+// The actual declaration with another
+char * const SCREEN = 0x0400;
+char idx;
+
+// And a little code using them
+void main() {
+    SCREEN[idx++] = 'c';
+    SCREEN[idx++] = 'm';
+    SCREEN[idx++] = 'l';
+}
+
+
+
+
+
+
+
+
+
+
+
+
diff --git a/src/test/kc/cstyle-decl-var-missing.kc b/src/test/kc/cstyle-decl-var-missing.kc
new file mode 100644
index 000000000..489a37b14
--- /dev/null
+++ b/src/test/kc/cstyle-decl-var-missing.kc
@@ -0,0 +1,22 @@
+// Test declarations of variables
+// Missing definition
+
+// The definition
+extern char * const SCREEN = 0x0400;
+
+//Second definition
+char idx;
+
+// And a little code using them
+void main() {
+    SCREEN[idx++] = 'c';
+    SCREEN[idx++] = 'm';
+    SCREEN[idx++] = 'l';
+}
+
+
+
+
+
+
+
diff --git a/src/test/kc/cstyle-decl-var-multiple.kc b/src/test/kc/cstyle-decl-var-multiple.kc
new file mode 100644
index 000000000..d70f7edc9
--- /dev/null
+++ b/src/test/kc/cstyle-decl-var-multiple.kc
@@ -0,0 +1,18 @@
+// Test legal definition of multiple local variables with the same name
+
+char * const SCREEN = 0x0400;
+char idx;
+
+// And a little code using them
+void main() {
+    for( char c: 0..10)
+        for( char c: 0..10)
+            SCREEN[idx++] = '*';
+}
+
+
+
+
+
+
+
diff --git a/src/test/kc/cstyle-decl-var-redefinition.kc b/src/test/kc/cstyle-decl-var-redefinition.kc
new file mode 100644
index 000000000..0111df8ec
--- /dev/null
+++ b/src/test/kc/cstyle-decl-var-redefinition.kc
@@ -0,0 +1,23 @@
+// Test declarations of variables
+// Redefinition
+
+//First definition
+char * const SCREEN = 0x0400;
+
+//Second definition
+char * const SCREEN = 0x0400;
+char idx;
+
+// And a little code using them
+void main() {
+    SCREEN[idx++] = 'c';
+    SCREEN[idx++] = 'm';
+    SCREEN[idx++] = 'l';
+}
+
+
+
+
+
+
+
diff --git a/src/test/kc/cstyle-decl-var.kc b/src/test/kc/cstyle-decl-var.kc
new file mode 100644
index 000000000..709df172f
--- /dev/null
+++ b/src/test/kc/cstyle-decl-var.kc
@@ -0,0 +1,23 @@
+// Test declarations of variables without definition
+
+// A few externs
+extern char * const SCREEN;
+extern char idx;
+
+// The actual declarations
+char * const SCREEN = 0x0400;
+char idx;
+
+// And a little code using them
+void main() {
+    SCREEN[idx++] = 'c';
+    SCREEN[idx++] = 'm';
+    SCREEN[idx++] = 'l';
+}
+
+
+
+
+
+
+
diff --git a/src/test/ref/cstyle-decl-0.asm b/src/test/ref/cstyle-decl-function.asm
similarity index 100%
rename from src/test/ref/cstyle-decl-0.asm
rename to src/test/ref/cstyle-decl-function.asm
diff --git a/src/test/ref/cstyle-decl-0.cfg b/src/test/ref/cstyle-decl-function.cfg
similarity index 100%
rename from src/test/ref/cstyle-decl-0.cfg
rename to src/test/ref/cstyle-decl-function.cfg
diff --git a/src/test/ref/cstyle-decl-0.log b/src/test/ref/cstyle-decl-function.log
similarity index 100%
rename from src/test/ref/cstyle-decl-0.log
rename to src/test/ref/cstyle-decl-function.log
diff --git a/src/test/ref/cstyle-decl-0.sym b/src/test/ref/cstyle-decl-function.sym
similarity index 100%
rename from src/test/ref/cstyle-decl-0.sym
rename to src/test/ref/cstyle-decl-function.sym
diff --git a/src/test/ref/cstyle-decl-var-multiple.asm b/src/test/ref/cstyle-decl-var-multiple.asm
new file mode 100644
index 000000000..66bfdf20e
--- /dev/null
+++ b/src/test/ref/cstyle-decl-var-multiple.asm
@@ -0,0 +1,30 @@
+// Test legal definition of multiple local variables with the same name
+.pc = $801 "Basic"
+:BasicUpstart(main)
+.pc = $80d "Program"
+  .label SCREEN = $400
+// And a little code using them
+main: {
+    .label c = 2
+    lda #0
+    sta.z c
+    tay
+  __b1:
+    ldx #0
+  __b2:
+    // SCREEN[idx++] = '*'
+    lda #'*'
+    sta SCREEN,y
+    // SCREEN[idx++] = '*';
+    iny
+    // for( char c: 0..10)
+    inx
+    cpx #$b
+    bne __b2
+    inc.z c
+    lda #$b
+    cmp.z c
+    bne __b1
+    // }
+    rts
+}
diff --git a/src/test/ref/cstyle-decl-var-multiple.cfg b/src/test/ref/cstyle-decl-var-multiple.cfg
new file mode 100644
index 000000000..1774ec82d
--- /dev/null
+++ b/src/test/ref/cstyle-decl-var-multiple.cfg
@@ -0,0 +1,33 @@
+@begin: scope:[]  from
+  [0] phi()
+  to:@1
+@1: scope:[]  from @begin
+  [1] phi()
+  [2] call main 
+  to:@end
+@end: scope:[]  from @1
+  [3] phi()
+
+(void()) main()
+main: scope:[main]  from @1
+  [4] phi()
+  to:main::@1
+main::@1: scope:[main]  from main main::@3
+  [5] (byte) main::c#4 ← phi( main/(byte) 0 main::@3/(byte) main::c#1 )
+  [5] (byte) idx#7 ← phi( main/(byte) 0 main::@3/(byte) idx#1 )
+  to:main::@2
+main::@2: scope:[main]  from main::@1 main::@2
+  [6] (byte) main::c1#2 ← phi( main::@1/(byte) 0 main::@2/(byte) main::c1#1 )
+  [6] (byte) idx#4 ← phi( main::@1/(byte) idx#7 main::@2/(byte) idx#1 )
+  [7] *((const nomodify byte*) SCREEN + (byte) idx#4) ← (byte) '*'
+  [8] (byte) idx#1 ← ++ (byte) idx#4
+  [9] (byte) main::c1#1 ← ++ (byte) main::c1#2
+  [10] if((byte) main::c1#1!=(byte) $b) goto main::@2
+  to:main::@3
+main::@3: scope:[main]  from main::@2
+  [11] (byte) main::c#1 ← ++ (byte) main::c#4
+  [12] if((byte) main::c#1!=(byte) $b) goto main::@1
+  to:main::@return
+main::@return: scope:[main]  from main::@3
+  [13] return 
+  to:@return
diff --git a/src/test/ref/cstyle-decl-var-multiple.log b/src/test/ref/cstyle-decl-var-multiple.log
new file mode 100644
index 000000000..9f84d6df0
--- /dev/null
+++ b/src/test/ref/cstyle-decl-var-multiple.log
@@ -0,0 +1,531 @@
+Culled Empty Block (label) main::@4
+
+CONTROL FLOW GRAPH SSA
+@begin: scope:[]  from
+  (byte) idx#0 ← (byte) 0
+  to:@1
+
+(void()) main()
+main: scope:[main]  from @1
+  (byte) idx#10 ← phi( @1/(byte) idx#9 )
+  (byte) main::c#0 ← (byte) 0
+  to:main::@1
+main::@1: scope:[main]  from main main::@3
+  (byte) main::c#4 ← phi( main/(byte) main::c#0 main::@3/(byte) main::c#1 )
+  (byte) idx#7 ← phi( main/(byte) idx#10 main::@3/(byte) idx#8 )
+  (byte) main::c1#0 ← (byte) 0
+  to:main::@2
+main::@2: scope:[main]  from main::@1 main::@2
+  (byte) main::c#3 ← phi( main::@1/(byte) main::c#4 main::@2/(byte) main::c#3 )
+  (byte) main::c1#2 ← phi( main::@1/(byte) main::c1#0 main::@2/(byte) main::c1#1 )
+  (byte) idx#4 ← phi( main::@1/(byte) idx#7 main::@2/(byte) idx#1 )
+  *((const nomodify byte*) SCREEN + (byte) idx#4) ← (byte) '*'
+  (byte) idx#1 ← ++ (byte) idx#4
+  (byte) main::c1#1 ← (byte) main::c1#2 + rangenext(0,$a)
+  (bool~) main::$0 ← (byte) main::c1#1 != rangelast(0,$a)
+  if((bool~) main::$0) goto main::@2
+  to:main::@3
+main::@3: scope:[main]  from main::@2
+  (byte) idx#8 ← phi( main::@2/(byte) idx#1 )
+  (byte) main::c#2 ← phi( main::@2/(byte) main::c#3 )
+  (byte) main::c#1 ← (byte) main::c#2 + rangenext(0,$a)
+  (bool~) main::$1 ← (byte) main::c#1 != rangelast(0,$a)
+  if((bool~) main::$1) goto main::@1
+  to:main::@return
+main::@return: scope:[main]  from main::@3
+  (byte) idx#5 ← phi( main::@3/(byte) idx#8 )
+  (byte) idx#2 ← (byte) idx#5
+  return 
+  to:@return
+@1: scope:[]  from @begin
+  (byte) idx#9 ← phi( @begin/(byte) idx#0 )
+  call main 
+  to:@2
+@2: scope:[]  from @1
+  (byte) idx#6 ← phi( @1/(byte) idx#2 )
+  (byte) idx#3 ← (byte) idx#6
+  to:@end
+@end: scope:[]  from @2
+
+SYMBOL TABLE SSA
+(label) @1
+(label) @2
+(label) @begin
+(label) @end
+(const nomodify byte*) SCREEN = (byte*)(number) $400
+(byte) idx
+(byte) idx#0
+(byte) idx#1
+(byte) idx#10
+(byte) idx#2
+(byte) idx#3
+(byte) idx#4
+(byte) idx#5
+(byte) idx#6
+(byte) idx#7
+(byte) idx#8
+(byte) idx#9
+(void()) main()
+(bool~) main::$0
+(bool~) main::$1
+(label) main::@1
+(label) main::@2
+(label) main::@3
+(label) main::@return
+(byte) main::c
+(byte) main::c#0
+(byte) main::c#1
+(byte) main::c#2
+(byte) main::c#3
+(byte) main::c#4
+(byte) main::c1
+(byte) main::c1#0
+(byte) main::c1#1
+(byte) main::c1#2
+
+Simplifying constant pointer cast (byte*) 1024
+Successful SSA optimization PassNCastSimplification
+Alias main::c#2 = main::c#3 
+Alias idx#1 = idx#8 idx#5 idx#2 
+Alias idx#0 = idx#9 
+Alias idx#3 = idx#6 
+Successful SSA optimization Pass2AliasElimination
+Identical Phi Values (byte) idx#10 (byte) idx#0
+Identical Phi Values (byte) main::c#2 (byte) main::c#4
+Identical Phi Values (byte) idx#3 (byte) idx#1
+Successful SSA optimization Pass2IdenticalPhiElimination
+Simple Condition (bool~) main::$0 [10] if((byte) main::c1#1!=rangelast(0,$a)) goto main::@2
+Simple Condition (bool~) main::$1 [13] if((byte) main::c#1!=rangelast(0,$a)) goto main::@1
+Successful SSA optimization Pass2ConditionalJumpSimplification
+Constant (const byte) idx#0 = 0
+Constant (const byte) main::c#0 = 0
+Constant (const byte) main::c1#0 = 0
+Successful SSA optimization Pass2ConstantIdentification
+Resolved ranged next value [8] main::c1#1 ← ++ main::c1#2 to ++
+Resolved ranged comparison value [10] if(main::c1#1!=rangelast(0,$a)) goto main::@2 to (number) $b
+Resolved ranged next value [11] main::c#1 ← ++ main::c#4 to ++
+Resolved ranged comparison value [13] if(main::c#1!=rangelast(0,$a)) goto main::@1 to (number) $b
+Adding number conversion cast (unumber) $b in if((byte) main::c1#1!=(number) $b) goto main::@2
+Adding number conversion cast (unumber) $b in if((byte) main::c#1!=(number) $b) goto main::@1
+Successful SSA optimization PassNAddNumberTypeConversions
+Simplifying constant integer cast $b
+Simplifying constant integer cast $b
+Successful SSA optimization PassNCastSimplification
+Finalized unsigned number type (byte) $b
+Finalized unsigned number type (byte) $b
+Successful SSA optimization PassNFinalizeNumberTypeConversions
+Inlining constant with var siblings (const byte) main::c#0
+Inlining constant with var siblings (const byte) main::c1#0
+Inlining constant with var siblings (const byte) idx#0
+Constant inlined main::c1#0 = (byte) 0
+Constant inlined main::c#0 = (byte) 0
+Constant inlined idx#0 = (byte) 0
+Successful SSA optimization Pass2ConstantInlining
+Added new block during phi lifting main::@5(between main::@3 and main::@1)
+Added new block during phi lifting main::@6(between main::@2 and main::@2)
+Adding NOP phi() at start of @begin
+Adding NOP phi() at start of @1
+Adding NOP phi() at start of @2
+Adding NOP phi() at start of @end
+Adding NOP phi() at start of main
+CALL GRAPH
+Calls in [] to main:2 
+
+Created 4 initial phi equivalence classes
+Coalesced [7] idx#12 ← idx#7
+Coalesced [16] idx#11 ← idx#1
+Coalesced [17] main::c#5 ← main::c#1
+Coalesced (already) [18] idx#13 ← idx#1
+Coalesced [19] main::c1#3 ← main::c1#1
+Coalesced down to 3 phi equivalence classes
+Culled Empty Block (label) @2
+Culled Empty Block (label) main::@5
+Culled Empty Block (label) main::@6
+Adding NOP phi() at start of @begin
+Adding NOP phi() at start of @1
+Adding NOP phi() at start of @end
+Adding NOP phi() at start of main
+
+FINAL CONTROL FLOW GRAPH
+@begin: scope:[]  from
+  [0] phi()
+  to:@1
+@1: scope:[]  from @begin
+  [1] phi()
+  [2] call main 
+  to:@end
+@end: scope:[]  from @1
+  [3] phi()
+
+(void()) main()
+main: scope:[main]  from @1
+  [4] phi()
+  to:main::@1
+main::@1: scope:[main]  from main main::@3
+  [5] (byte) main::c#4 ← phi( main/(byte) 0 main::@3/(byte) main::c#1 )
+  [5] (byte) idx#7 ← phi( main/(byte) 0 main::@3/(byte) idx#1 )
+  to:main::@2
+main::@2: scope:[main]  from main::@1 main::@2
+  [6] (byte) main::c1#2 ← phi( main::@1/(byte) 0 main::@2/(byte) main::c1#1 )
+  [6] (byte) idx#4 ← phi( main::@1/(byte) idx#7 main::@2/(byte) idx#1 )
+  [7] *((const nomodify byte*) SCREEN + (byte) idx#4) ← (byte) '*'
+  [8] (byte) idx#1 ← ++ (byte) idx#4
+  [9] (byte) main::c1#1 ← ++ (byte) main::c1#2
+  [10] if((byte) main::c1#1!=(byte) $b) goto main::@2
+  to:main::@3
+main::@3: scope:[main]  from main::@2
+  [11] (byte) main::c#1 ← ++ (byte) main::c#4
+  [12] if((byte) main::c#1!=(byte) $b) goto main::@1
+  to:main::@return
+main::@return: scope:[main]  from main::@3
+  [13] return 
+  to:@return
+
+
+VARIABLE REGISTER WEIGHTS
+(byte) idx
+(byte) idx#1 420.59999999999997
+(byte) idx#4 1552.0
+(byte) idx#7 202.0
+(void()) main()
+(byte) main::c
+(byte) main::c#1 151.5
+(byte) main::c#4 33.666666666666664
+(byte) main::c1
+(byte) main::c1#1 1501.5
+(byte) main::c1#2 667.3333333333334
+
+Initial phi equivalence classes
+[ main::c#4 main::c#1 ]
+[ idx#4 idx#7 idx#1 ]
+[ main::c1#2 main::c1#1 ]
+Complete equivalence classes
+[ main::c#4 main::c#1 ]
+[ idx#4 idx#7 idx#1 ]
+[ main::c1#2 main::c1#1 ]
+Allocated zp[1]:2 [ main::c#4 main::c#1 ]
+Allocated zp[1]:3 [ idx#4 idx#7 idx#1 ]
+Allocated zp[1]:4 [ main::c1#2 main::c1#1 ]
+
+INITIAL ASM
+Target platform is c64basic / MOS6502X
+  // File Comments
+// Test legal definition of multiple local variables with the same name
+  // Upstart
+.pc = $801 "Basic"
+:BasicUpstart(__bbegin)
+.pc = $80d "Program"
+  // Global Constants & labels
+  .label SCREEN = $400
+  .label idx = 3
+  // @begin
+__bbegin:
+  // [1] phi from @begin to @1 [phi:@begin->@1]
+__b1_from___bbegin:
+  jmp __b1
+  // @1
+__b1:
+  // [2] call main 
+  // [4] phi from @1 to main [phi:@1->main]
+main_from___b1:
+  jsr main
+  // [3] phi from @1 to @end [phi:@1->@end]
+__bend_from___b1:
+  jmp __bend
+  // @end
+__bend:
+  // main
+// And a little code using them
+main: {
+    .label c1 = 4
+    .label c = 2
+    // [5] phi from main to main::@1 [phi:main->main::@1]
+  __b1_from_main:
+    // [5] phi (byte) main::c#4 = (byte) 0 [phi:main->main::@1#0] -- vbuz1=vbuc1 
+    lda #0
+    sta.z c
+    // [5] phi (byte) idx#7 = (byte) 0 [phi:main->main::@1#1] -- vbuz1=vbuc1 
+    lda #0
+    sta.z idx
+    jmp __b1
+    // [5] phi from main::@3 to main::@1 [phi:main::@3->main::@1]
+  __b1_from___b3:
+    // [5] phi (byte) main::c#4 = (byte) main::c#1 [phi:main::@3->main::@1#0] -- register_copy 
+    // [5] phi (byte) idx#7 = (byte) idx#1 [phi:main::@3->main::@1#1] -- register_copy 
+    jmp __b1
+    // main::@1
+  __b1:
+    // [6] phi from main::@1 to main::@2 [phi:main::@1->main::@2]
+  __b2_from___b1:
+    // [6] phi (byte) main::c1#2 = (byte) 0 [phi:main::@1->main::@2#0] -- vbuz1=vbuc1 
+    lda #0
+    sta.z c1
+    // [6] phi (byte) idx#4 = (byte) idx#7 [phi:main::@1->main::@2#1] -- register_copy 
+    jmp __b2
+    // [6] phi from main::@2 to main::@2 [phi:main::@2->main::@2]
+  __b2_from___b2:
+    // [6] phi (byte) main::c1#2 = (byte) main::c1#1 [phi:main::@2->main::@2#0] -- register_copy 
+    // [6] phi (byte) idx#4 = (byte) idx#1 [phi:main::@2->main::@2#1] -- register_copy 
+    jmp __b2
+    // main::@2
+  __b2:
+    // [7] *((const nomodify byte*) SCREEN + (byte) idx#4) ← (byte) '*' -- pbuc1_derefidx_vbuz1=vbuc2 
+    lda #'*'
+    ldy.z idx
+    sta SCREEN,y
+    // [8] (byte) idx#1 ← ++ (byte) idx#4 -- vbuz1=_inc_vbuz1 
+    inc.z idx
+    // [9] (byte) main::c1#1 ← ++ (byte) main::c1#2 -- vbuz1=_inc_vbuz1 
+    inc.z c1
+    // [10] if((byte) main::c1#1!=(byte) $b) goto main::@2 -- vbuz1_neq_vbuc1_then_la1 
+    lda #$b
+    cmp.z c1
+    bne __b2_from___b2
+    jmp __b3
+    // main::@3
+  __b3:
+    // [11] (byte) main::c#1 ← ++ (byte) main::c#4 -- vbuz1=_inc_vbuz1 
+    inc.z c
+    // [12] if((byte) main::c#1!=(byte) $b) goto main::@1 -- vbuz1_neq_vbuc1_then_la1 
+    lda #$b
+    cmp.z c
+    bne __b1_from___b3
+    jmp __breturn
+    // main::@return
+  __breturn:
+    // [13] return 
+    rts
+}
+  // File Data
+
+REGISTER UPLIFT POTENTIAL REGISTERS
+Statement [7] *((const nomodify byte*) SCREEN + (byte) idx#4) ← (byte) '*' [ main::c#4 idx#4 main::c1#2 ] ( main:2 [ main::c#4 idx#4 main::c1#2 ] { }  ) always clobbers reg byte a 
+Removing always clobbered register reg byte a as potential for zp[1]:2 [ main::c#4 main::c#1 ]
+Removing always clobbered register reg byte a as potential for zp[1]:3 [ idx#4 idx#7 idx#1 ]
+Removing always clobbered register reg byte a as potential for zp[1]:4 [ main::c1#2 main::c1#1 ]
+Statement [7] *((const nomodify byte*) SCREEN + (byte) idx#4) ← (byte) '*' [ main::c#4 idx#4 main::c1#2 ] ( main:2 [ main::c#4 idx#4 main::c1#2 ] { }  ) always clobbers reg byte a 
+Potential registers zp[1]:2 [ main::c#4 main::c#1 ] : zp[1]:2 , reg byte x , reg byte y , 
+Potential registers zp[1]:3 [ idx#4 idx#7 idx#1 ] : zp[1]:3 , reg byte x , reg byte y , 
+Potential registers zp[1]:4 [ main::c1#2 main::c1#1 ] : zp[1]:4 , reg byte x , reg byte y , 
+
+REGISTER UPLIFT SCOPES
+Uplift Scope [main] 2,168.83: zp[1]:4 [ main::c1#2 main::c1#1 ] 185.17: zp[1]:2 [ main::c#4 main::c#1 ] 
+Uplift Scope [] 2,174.6: zp[1]:3 [ idx#4 idx#7 idx#1 ] 
+
+Uplifting [main] best 3583 combination reg byte x [ main::c1#2 main::c1#1 ] zp[1]:2 [ main::c#4 main::c#1 ] 
+Uplifting [] best 2953 combination reg byte y [ idx#4 idx#7 idx#1 ] 
+Attempting to uplift remaining variables inzp[1]:2 [ main::c#4 main::c#1 ]
+Uplifting [main] best 2953 combination zp[1]:2 [ main::c#4 main::c#1 ] 
+
+ASSEMBLER BEFORE OPTIMIZATION
+  // File Comments
+// Test legal definition of multiple local variables with the same name
+  // Upstart
+.pc = $801 "Basic"
+:BasicUpstart(__bbegin)
+.pc = $80d "Program"
+  // Global Constants & labels
+  .label SCREEN = $400
+  // @begin
+__bbegin:
+  // [1] phi from @begin to @1 [phi:@begin->@1]
+__b1_from___bbegin:
+  jmp __b1
+  // @1
+__b1:
+  // [2] call main 
+  // [4] phi from @1 to main [phi:@1->main]
+main_from___b1:
+  jsr main
+  // [3] phi from @1 to @end [phi:@1->@end]
+__bend_from___b1:
+  jmp __bend
+  // @end
+__bend:
+  // main
+// And a little code using them
+main: {
+    .label c = 2
+    // [5] phi from main to main::@1 [phi:main->main::@1]
+  __b1_from_main:
+    // [5] phi (byte) main::c#4 = (byte) 0 [phi:main->main::@1#0] -- vbuz1=vbuc1 
+    lda #0
+    sta.z c
+    // [5] phi (byte) idx#7 = (byte) 0 [phi:main->main::@1#1] -- vbuyy=vbuc1 
+    ldy #0
+    jmp __b1
+    // [5] phi from main::@3 to main::@1 [phi:main::@3->main::@1]
+  __b1_from___b3:
+    // [5] phi (byte) main::c#4 = (byte) main::c#1 [phi:main::@3->main::@1#0] -- register_copy 
+    // [5] phi (byte) idx#7 = (byte) idx#1 [phi:main::@3->main::@1#1] -- register_copy 
+    jmp __b1
+    // main::@1
+  __b1:
+    // [6] phi from main::@1 to main::@2 [phi:main::@1->main::@2]
+  __b2_from___b1:
+    // [6] phi (byte) main::c1#2 = (byte) 0 [phi:main::@1->main::@2#0] -- vbuxx=vbuc1 
+    ldx #0
+    // [6] phi (byte) idx#4 = (byte) idx#7 [phi:main::@1->main::@2#1] -- register_copy 
+    jmp __b2
+    // [6] phi from main::@2 to main::@2 [phi:main::@2->main::@2]
+  __b2_from___b2:
+    // [6] phi (byte) main::c1#2 = (byte) main::c1#1 [phi:main::@2->main::@2#0] -- register_copy 
+    // [6] phi (byte) idx#4 = (byte) idx#1 [phi:main::@2->main::@2#1] -- register_copy 
+    jmp __b2
+    // main::@2
+  __b2:
+    // [7] *((const nomodify byte*) SCREEN + (byte) idx#4) ← (byte) '*' -- pbuc1_derefidx_vbuyy=vbuc2 
+    lda #'*'
+    sta SCREEN,y
+    // [8] (byte) idx#1 ← ++ (byte) idx#4 -- vbuyy=_inc_vbuyy 
+    iny
+    // [9] (byte) main::c1#1 ← ++ (byte) main::c1#2 -- vbuxx=_inc_vbuxx 
+    inx
+    // [10] if((byte) main::c1#1!=(byte) $b) goto main::@2 -- vbuxx_neq_vbuc1_then_la1 
+    cpx #$b
+    bne __b2_from___b2
+    jmp __b3
+    // main::@3
+  __b3:
+    // [11] (byte) main::c#1 ← ++ (byte) main::c#4 -- vbuz1=_inc_vbuz1 
+    inc.z c
+    // [12] if((byte) main::c#1!=(byte) $b) goto main::@1 -- vbuz1_neq_vbuc1_then_la1 
+    lda #$b
+    cmp.z c
+    bne __b1_from___b3
+    jmp __breturn
+    // main::@return
+  __breturn:
+    // [13] return 
+    rts
+}
+  // File Data
+
+ASSEMBLER OPTIMIZATIONS
+Removing instruction jmp __b1
+Removing instruction jmp __bend
+Removing instruction jmp __b1
+Removing instruction jmp __b2
+Removing instruction jmp __b3
+Removing instruction jmp __breturn
+Succesful ASM optimization Pass5NextJumpElimination
+Replacing instruction ldy #0 with TAY
+Replacing label __b2_from___b2 with __b2
+Replacing label __b1_from___b3 with __b1
+Removing instruction __b1_from___bbegin:
+Removing instruction __b1:
+Removing instruction main_from___b1:
+Removing instruction __bend_from___b1:
+Removing instruction __b1_from___b3:
+Removing instruction __b2_from___b1:
+Removing instruction __b2_from___b2:
+Succesful ASM optimization Pass5RedundantLabelElimination
+Removing instruction __bend:
+Removing instruction __b1_from_main:
+Removing instruction __b3:
+Removing instruction __breturn:
+Succesful ASM optimization Pass5UnusedLabelElimination
+Updating BasicUpstart to call main directly
+Removing instruction jsr main
+Succesful ASM optimization Pass5SkipBegin
+Removing instruction jmp __b1
+Removing instruction jmp __b2
+Succesful ASM optimization Pass5NextJumpElimination
+Removing instruction __bbegin:
+Succesful ASM optimization Pass5UnusedLabelElimination
+
+FINAL SYMBOL TABLE
+(label) @1
+(label) @begin
+(label) @end
+(const nomodify byte*) SCREEN = (byte*) 1024
+(byte) idx
+(byte) idx#1 reg byte y 420.59999999999997
+(byte) idx#4 reg byte y 1552.0
+(byte) idx#7 reg byte y 202.0
+(void()) main()
+(label) main::@1
+(label) main::@2
+(label) main::@3
+(label) main::@return
+(byte) main::c
+(byte) main::c#1 c zp[1]:2 151.5
+(byte) main::c#4 c zp[1]:2 33.666666666666664
+(byte) main::c1
+(byte) main::c1#1 reg byte x 1501.5
+(byte) main::c1#2 reg byte x 667.3333333333334
+
+zp[1]:2 [ main::c#4 main::c#1 ]
+reg byte y [ idx#4 idx#7 idx#1 ]
+reg byte x [ main::c1#2 main::c1#1 ]
+
+
+FINAL ASSEMBLER
+Score: 1951
+
+  // File Comments
+// Test legal definition of multiple local variables with the same name
+  // Upstart
+.pc = $801 "Basic"
+:BasicUpstart(main)
+.pc = $80d "Program"
+  // Global Constants & labels
+  .label SCREEN = $400
+  // @begin
+  // [1] phi from @begin to @1 [phi:@begin->@1]
+  // @1
+  // [2] call main 
+  // [4] phi from @1 to main [phi:@1->main]
+  // [3] phi from @1 to @end [phi:@1->@end]
+  // @end
+  // main
+// And a little code using them
+main: {
+    .label c = 2
+    // [5] phi from main to main::@1 [phi:main->main::@1]
+    // [5] phi (byte) main::c#4 = (byte) 0 [phi:main->main::@1#0] -- vbuz1=vbuc1 
+    lda #0
+    sta.z c
+    // [5] phi (byte) idx#7 = (byte) 0 [phi:main->main::@1#1] -- vbuyy=vbuc1 
+    tay
+    // [5] phi from main::@3 to main::@1 [phi:main::@3->main::@1]
+    // [5] phi (byte) main::c#4 = (byte) main::c#1 [phi:main::@3->main::@1#0] -- register_copy 
+    // [5] phi (byte) idx#7 = (byte) idx#1 [phi:main::@3->main::@1#1] -- register_copy 
+    // main::@1
+  __b1:
+    // [6] phi from main::@1 to main::@2 [phi:main::@1->main::@2]
+    // [6] phi (byte) main::c1#2 = (byte) 0 [phi:main::@1->main::@2#0] -- vbuxx=vbuc1 
+    ldx #0
+    // [6] phi (byte) idx#4 = (byte) idx#7 [phi:main::@1->main::@2#1] -- register_copy 
+    // [6] phi from main::@2 to main::@2 [phi:main::@2->main::@2]
+    // [6] phi (byte) main::c1#2 = (byte) main::c1#1 [phi:main::@2->main::@2#0] -- register_copy 
+    // [6] phi (byte) idx#4 = (byte) idx#1 [phi:main::@2->main::@2#1] -- register_copy 
+    // main::@2
+  __b2:
+    // SCREEN[idx++] = '*'
+    // [7] *((const nomodify byte*) SCREEN + (byte) idx#4) ← (byte) '*' -- pbuc1_derefidx_vbuyy=vbuc2 
+    lda #'*'
+    sta SCREEN,y
+    // SCREEN[idx++] = '*';
+    // [8] (byte) idx#1 ← ++ (byte) idx#4 -- vbuyy=_inc_vbuyy 
+    iny
+    // for( char c: 0..10)
+    // [9] (byte) main::c1#1 ← ++ (byte) main::c1#2 -- vbuxx=_inc_vbuxx 
+    inx
+    // [10] if((byte) main::c1#1!=(byte) $b) goto main::@2 -- vbuxx_neq_vbuc1_then_la1 
+    cpx #$b
+    bne __b2
+    // main::@3
+    // [11] (byte) main::c#1 ← ++ (byte) main::c#4 -- vbuz1=_inc_vbuz1 
+    inc.z c
+    // [12] if((byte) main::c#1!=(byte) $b) goto main::@1 -- vbuz1_neq_vbuc1_then_la1 
+    lda #$b
+    cmp.z c
+    bne __b1
+    // main::@return
+    // }
+    // [13] return 
+    rts
+}
+  // File Data
+
diff --git a/src/test/ref/cstyle-decl-var-multiple.sym b/src/test/ref/cstyle-decl-var-multiple.sym
new file mode 100644
index 000000000..1e1675fd6
--- /dev/null
+++ b/src/test/ref/cstyle-decl-var-multiple.sym
@@ -0,0 +1,23 @@
+(label) @1
+(label) @begin
+(label) @end
+(const nomodify byte*) SCREEN = (byte*) 1024
+(byte) idx
+(byte) idx#1 reg byte y 420.59999999999997
+(byte) idx#4 reg byte y 1552.0
+(byte) idx#7 reg byte y 202.0
+(void()) main()
+(label) main::@1
+(label) main::@2
+(label) main::@3
+(label) main::@return
+(byte) main::c
+(byte) main::c#1 c zp[1]:2 151.5
+(byte) main::c#4 c zp[1]:2 33.666666666666664
+(byte) main::c1
+(byte) main::c1#1 reg byte x 1501.5
+(byte) main::c1#2 reg byte x 667.3333333333334
+
+zp[1]:2 [ main::c#4 main::c#1 ]
+reg byte y [ idx#4 idx#7 idx#1 ]
+reg byte x [ main::c1#2 main::c1#1 ]
diff --git a/src/test/ref/cstyle-decl-var.asm b/src/test/ref/cstyle-decl-var.asm
new file mode 100644
index 000000000..2f51996bf
--- /dev/null
+++ b/src/test/ref/cstyle-decl-var.asm
@@ -0,0 +1,20 @@
+// Test declarations of variables without definition
+.pc = $801 "Basic"
+:BasicUpstart(main)
+.pc = $80d "Program"
+  // The actual declarations
+  .label SCREEN = $400
+// And a little code using them
+main: {
+    // SCREEN[idx++] = 'c'
+    lda #'c'
+    sta SCREEN
+    // SCREEN[idx++] = 'm'
+    lda #'m'
+    sta SCREEN+1
+    // SCREEN[idx++] = 'l'
+    lda #'l'
+    sta SCREEN+2
+    // }
+    rts
+}
diff --git a/src/test/ref/cstyle-decl-var.cfg b/src/test/ref/cstyle-decl-var.cfg
new file mode 100644
index 000000000..334c4a0c3
--- /dev/null
+++ b/src/test/ref/cstyle-decl-var.cfg
@@ -0,0 +1,19 @@
+@begin: scope:[]  from
+  [0] phi()
+  to:@1
+@1: scope:[]  from @begin
+  [1] phi()
+  [2] call main 
+  to:@end
+@end: scope:[]  from @1
+  [3] phi()
+
+(void()) main()
+main: scope:[main]  from @1
+  [4] *((const nomodify byte*) SCREEN) ← (byte) 'c'
+  [5] *((const nomodify byte*) SCREEN+(byte) 1) ← (byte) 'm'
+  [6] *((const nomodify byte*) SCREEN+(byte) 2) ← (byte) 'l'
+  to:main::@return
+main::@return: scope:[main]  from main
+  [7] return 
+  to:@return
diff --git a/src/test/ref/cstyle-decl-var.log b/src/test/ref/cstyle-decl-var.log
new file mode 100644
index 000000000..95e860568
--- /dev/null
+++ b/src/test/ref/cstyle-decl-var.log
@@ -0,0 +1,306 @@
+
+CONTROL FLOW GRAPH SSA
+@begin: scope:[]  from
+  (byte) idx#0 ← (byte) 0
+  (byte) idx#1 ← (byte) 0
+  to:@1
+
+(void()) main()
+main: scope:[main]  from @1
+  (byte) idx#7 ← phi( @1/(byte) idx#10 )
+  *((const nomodify byte*) SCREEN + (byte) idx#7) ← (byte) 'c'
+  (byte) idx#2 ← ++ (byte) idx#7
+  *((const nomodify byte*) SCREEN + (byte) idx#2) ← (byte) 'm'
+  (byte) idx#3 ← ++ (byte) idx#2
+  *((const nomodify byte*) SCREEN + (byte) idx#3) ← (byte) 'l'
+  (byte) idx#4 ← ++ (byte) idx#3
+  to:main::@return
+main::@return: scope:[main]  from main
+  (byte) idx#8 ← phi( main/(byte) idx#4 )
+  (byte) idx#5 ← (byte) idx#8
+  return 
+  to:@return
+@1: scope:[]  from @begin
+  (byte) idx#10 ← phi( @begin/(byte) idx#1 )
+  call main 
+  to:@2
+@2: scope:[]  from @1
+  (byte) idx#9 ← phi( @1/(byte) idx#5 )
+  (byte) idx#6 ← (byte) idx#9
+  to:@end
+@end: scope:[]  from @2
+
+SYMBOL TABLE SSA
+(label) @1
+(label) @2
+(label) @begin
+(label) @end
+(const nomodify byte*) SCREEN = (byte*)(number) $400
+(byte) idx
+(byte) idx#0
+(byte) idx#1
+(byte) idx#10
+(byte) idx#2
+(byte) idx#3
+(byte) idx#4
+(byte) idx#5
+(byte) idx#6
+(byte) idx#7
+(byte) idx#8
+(byte) idx#9
+(void()) main()
+(label) main::@return
+
+Simplifying constant pointer cast (byte*) 1024
+Successful SSA optimization PassNCastSimplification
+Alias idx#4 = idx#8 idx#5 
+Alias idx#1 = idx#10 
+Alias idx#6 = idx#9 
+Successful SSA optimization Pass2AliasElimination
+Identical Phi Values (byte) idx#7 (byte) idx#1
+Identical Phi Values (byte) idx#6 (byte) idx#4
+Successful SSA optimization Pass2IdenticalPhiElimination
+Constant (const byte) idx#0 = 0
+Constant (const byte) idx#1 = 0
+Successful SSA optimization Pass2ConstantIdentification
+Simplifying expression containing zero SCREEN in [3] *((const nomodify byte*) SCREEN + (const byte) idx#1) ← (byte) 'c'
+Successful SSA optimization PassNSimplifyExpressionWithZero
+Eliminating unused variable (byte) idx#4 and assignment [5] (byte) idx#4 ← ++ (byte) idx#3
+Eliminating unused constant (const byte) idx#0
+Successful SSA optimization PassNEliminateUnusedVars
+Constant right-side identified [1] (byte) idx#2 ← ++ (const byte) idx#1
+Successful SSA optimization Pass2ConstantRValueConsolidation
+Constant (const byte) idx#2 = ++idx#1
+Successful SSA optimization Pass2ConstantIdentification
+Constant right-side identified [2] (byte) idx#3 ← ++ (const byte) idx#2
+Successful SSA optimization Pass2ConstantRValueConsolidation
+Constant (const byte) idx#3 = ++idx#2
+Successful SSA optimization Pass2ConstantIdentification
+Inlining constant with different constant siblings (const byte) idx#1
+Inlining constant with different constant siblings (const byte) idx#2
+Inlining constant with different constant siblings (const byte) idx#3
+Constant inlined idx#2 = ++(byte) 0
+Constant inlined idx#3 = ++++(byte) 0
+Constant inlined idx#1 = (byte) 0
+Successful SSA optimization Pass2ConstantInlining
+Consolidated array index constant in *(SCREEN+++0)
+Consolidated array index constant in *(SCREEN+++++0)
+Successful SSA optimization Pass2ConstantAdditionElimination
+Simplifying constant integer increment ++0
+Simplifying constant integer increment ++0
+Successful SSA optimization Pass2ConstantSimplification
+Simplifying constant integer increment ++1
+Successful SSA optimization Pass2ConstantSimplification
+Adding NOP phi() at start of @begin
+Adding NOP phi() at start of @1
+Adding NOP phi() at start of @2
+Adding NOP phi() at start of @end
+CALL GRAPH
+Calls in [] to main:2 
+
+Created 0 initial phi equivalence classes
+Coalesced down to 0 phi equivalence classes
+Culled Empty Block (label) @2
+Adding NOP phi() at start of @begin
+Adding NOP phi() at start of @1
+Adding NOP phi() at start of @end
+
+FINAL CONTROL FLOW GRAPH
+@begin: scope:[]  from
+  [0] phi()
+  to:@1
+@1: scope:[]  from @begin
+  [1] phi()
+  [2] call main 
+  to:@end
+@end: scope:[]  from @1
+  [3] phi()
+
+(void()) main()
+main: scope:[main]  from @1
+  [4] *((const nomodify byte*) SCREEN) ← (byte) 'c'
+  [5] *((const nomodify byte*) SCREEN+(byte) 1) ← (byte) 'm'
+  [6] *((const nomodify byte*) SCREEN+(byte) 2) ← (byte) 'l'
+  to:main::@return
+main::@return: scope:[main]  from main
+  [7] return 
+  to:@return
+
+
+VARIABLE REGISTER WEIGHTS
+(byte) idx
+(void()) main()
+
+Initial phi equivalence classes
+Complete equivalence classes
+
+INITIAL ASM
+Target platform is c64basic / MOS6502X
+  // File Comments
+// Test declarations of variables without definition
+  // Upstart
+.pc = $801 "Basic"
+:BasicUpstart(__bbegin)
+.pc = $80d "Program"
+  // Global Constants & labels
+  // The actual declarations
+  .label SCREEN = $400
+  // @begin
+__bbegin:
+  // [1] phi from @begin to @1 [phi:@begin->@1]
+__b1_from___bbegin:
+  jmp __b1
+  // @1
+__b1:
+  // [2] call main 
+  jsr main
+  // [3] phi from @1 to @end [phi:@1->@end]
+__bend_from___b1:
+  jmp __bend
+  // @end
+__bend:
+  // main
+// And a little code using them
+main: {
+    // [4] *((const nomodify byte*) SCREEN) ← (byte) 'c' -- _deref_pbuc1=vbuc2 
+    lda #'c'
+    sta SCREEN
+    // [5] *((const nomodify byte*) SCREEN+(byte) 1) ← (byte) 'm' -- _deref_pbuc1=vbuc2 
+    lda #'m'
+    sta SCREEN+1
+    // [6] *((const nomodify byte*) SCREEN+(byte) 2) ← (byte) 'l' -- _deref_pbuc1=vbuc2 
+    lda #'l'
+    sta SCREEN+2
+    jmp __breturn
+    // main::@return
+  __breturn:
+    // [7] return 
+    rts
+}
+  // File Data
+
+REGISTER UPLIFT POTENTIAL REGISTERS
+Statement [4] *((const nomodify byte*) SCREEN) ← (byte) 'c' [ ] ( main:2 [ ] { }  ) always clobbers reg byte a 
+Statement [5] *((const nomodify byte*) SCREEN+(byte) 1) ← (byte) 'm' [ ] ( main:2 [ ] { }  ) always clobbers reg byte a 
+Statement [6] *((const nomodify byte*) SCREEN+(byte) 2) ← (byte) 'l' [ ] ( main:2 [ ] { }  ) always clobbers reg byte a 
+
+REGISTER UPLIFT SCOPES
+Uplift Scope [main] 
+Uplift Scope [] 
+
+Uplifting [main] best 39 combination 
+Uplifting [] best 39 combination 
+
+ASSEMBLER BEFORE OPTIMIZATION
+  // File Comments
+// Test declarations of variables without definition
+  // Upstart
+.pc = $801 "Basic"
+:BasicUpstart(__bbegin)
+.pc = $80d "Program"
+  // Global Constants & labels
+  // The actual declarations
+  .label SCREEN = $400
+  // @begin
+__bbegin:
+  // [1] phi from @begin to @1 [phi:@begin->@1]
+__b1_from___bbegin:
+  jmp __b1
+  // @1
+__b1:
+  // [2] call main 
+  jsr main
+  // [3] phi from @1 to @end [phi:@1->@end]
+__bend_from___b1:
+  jmp __bend
+  // @end
+__bend:
+  // main
+// And a little code using them
+main: {
+    // [4] *((const nomodify byte*) SCREEN) ← (byte) 'c' -- _deref_pbuc1=vbuc2 
+    lda #'c'
+    sta SCREEN
+    // [5] *((const nomodify byte*) SCREEN+(byte) 1) ← (byte) 'm' -- _deref_pbuc1=vbuc2 
+    lda #'m'
+    sta SCREEN+1
+    // [6] *((const nomodify byte*) SCREEN+(byte) 2) ← (byte) 'l' -- _deref_pbuc1=vbuc2 
+    lda #'l'
+    sta SCREEN+2
+    jmp __breturn
+    // main::@return
+  __breturn:
+    // [7] return 
+    rts
+}
+  // File Data
+
+ASSEMBLER OPTIMIZATIONS
+Removing instruction jmp __b1
+Removing instruction jmp __bend
+Removing instruction jmp __breturn
+Succesful ASM optimization Pass5NextJumpElimination
+Removing instruction __b1_from___bbegin:
+Removing instruction __b1:
+Removing instruction __bend_from___b1:
+Succesful ASM optimization Pass5RedundantLabelElimination
+Removing instruction __bend:
+Removing instruction __breturn:
+Succesful ASM optimization Pass5UnusedLabelElimination
+Updating BasicUpstart to call main directly
+Removing instruction jsr main
+Succesful ASM optimization Pass5SkipBegin
+Removing instruction __bbegin:
+Succesful ASM optimization Pass5UnusedLabelElimination
+
+FINAL SYMBOL TABLE
+(label) @1
+(label) @begin
+(label) @end
+(const nomodify byte*) SCREEN = (byte*) 1024
+(byte) idx
+(void()) main()
+(label) main::@return
+
+
+
+FINAL ASSEMBLER
+Score: 24
+
+  // File Comments
+// Test declarations of variables without definition
+  // Upstart
+.pc = $801 "Basic"
+:BasicUpstart(main)
+.pc = $80d "Program"
+  // Global Constants & labels
+  // The actual declarations
+  .label SCREEN = $400
+  // @begin
+  // [1] phi from @begin to @1 [phi:@begin->@1]
+  // @1
+  // [2] call main 
+  // [3] phi from @1 to @end [phi:@1->@end]
+  // @end
+  // main
+// And a little code using them
+main: {
+    // SCREEN[idx++] = 'c'
+    // [4] *((const nomodify byte*) SCREEN) ← (byte) 'c' -- _deref_pbuc1=vbuc2 
+    lda #'c'
+    sta SCREEN
+    // SCREEN[idx++] = 'm'
+    // [5] *((const nomodify byte*) SCREEN+(byte) 1) ← (byte) 'm' -- _deref_pbuc1=vbuc2 
+    lda #'m'
+    sta SCREEN+1
+    // SCREEN[idx++] = 'l'
+    // [6] *((const nomodify byte*) SCREEN+(byte) 2) ← (byte) 'l' -- _deref_pbuc1=vbuc2 
+    lda #'l'
+    sta SCREEN+2
+    // main::@return
+    // }
+    // [7] return 
+    rts
+}
+  // File Data
+
diff --git a/src/test/ref/cstyle-decl-var.sym b/src/test/ref/cstyle-decl-var.sym
new file mode 100644
index 000000000..2f5c57310
--- /dev/null
+++ b/src/test/ref/cstyle-decl-var.sym
@@ -0,0 +1,8 @@
+(label) @1
+(label) @begin
+(label) @end
+(const nomodify byte*) SCREEN = (byte*) 1024
+(byte) idx
+(void()) main()
+(label) main::@return
+