Constructing Control Flow Graph.

src/dk/camelot64/kickc/icl/Constant.java

@@ -0,0 +1,7 @@
+package dk.camelot64.kickc.icl;
+
+/** SSA form constant value */
+public interface Constant extends RValue {
+
+
+}

src/dk/camelot64/kickc/icl/ConstantBool.java

@@ -1,13 +1,13 @@
-package dk.camelot64.kickc.ssa;
+package dk.camelot64.kickc.icl;
 
 /**
  * SSA form constant integer value
  */
-public class SSAConstantBool implements SSAConstant {
+public class ConstantBool implements Constant {
 
    private Boolean value;
 
-   public SSAConstantBool(Boolean value) {
+   public ConstantBool(Boolean value) {
       this.value = value;
    }
 

src/dk/camelot64/kickc/icl/ConstantDouble.java

@@ -1,13 +1,13 @@
-package dk.camelot64.kickc.ssa;
+package dk.camelot64.kickc.icl;
 
 /**
  * SSA form constant integer value
  */
-public class SSAConstantDouble implements SSAConstant {
+public class ConstantDouble implements Constant {
 
    private Double number;
 
-   public SSAConstantDouble(Double number) {
+   public ConstantDouble(Double number) {
       this.number= number;
    }
 

src/dk/camelot64/kickc/icl/ConstantInteger.java

@@ -1,13 +1,13 @@
-package dk.camelot64.kickc.ssa;
+package dk.camelot64.kickc.icl;
 
 /**
  * SSA form constant integer value
  */
-public class SSAConstantInteger implements SSAConstant {
+public class ConstantInteger implements Constant {
 
    private Integer number;
 
-   public SSAConstantInteger(Integer number) {
+   public ConstantInteger(Integer number) {
       this.number = number;
    }
 

src/dk/camelot64/kickc/icl/ConstantString.java

@@ -1,13 +1,13 @@
-package dk.camelot64.kickc.ssa;
+package dk.camelot64.kickc.icl;
 
 /**
  * SSA form constant integer value
  */
-public class SSAConstantString implements SSAConstant {
+public class ConstantString implements Constant {
 
    private String value;
 
-   public SSAConstantString(String value) {
+   public ConstantString(String value) {
       this.value = value;
    }
 

src/dk/camelot64/kickc/icl/ControlFlowBlock.java

@@ -0,0 +1,101 @@
+package dk.camelot64.kickc.icl;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/** A named/labelled sequence of SSA statements connected to other basic blocks.
+ * The connections defines the control flow of the program. */
+public class ControlFlowBlock {
+
+   private Symbol label;
+
+   private List<ControlFlowBlock> predecessors;
+
+   private List<Statement> statements;
+
+   private ControlFlowBlock defaultSuccessor;
+
+   private ControlFlowBlock conditionalSuccessor;
+
+   public ControlFlowBlock(Symbol label) {
+      this.label = label;
+      this.statements = new ArrayList<>();
+      this.predecessors = new ArrayList<>();
+      this.defaultSuccessor = null;
+      this.conditionalSuccessor = null;
+   }
+
+   public Symbol getLabel() {
+      return label;
+   }
+
+   public void addStatement(Statement statement) {
+      this.statements.add(statement);
+   }
+
+   public void addPredecessor(ControlFlowBlock block) {
+      this.predecessors.add(block);
+   }
+
+   public void setDefaultSuccessor(ControlFlowBlock defaultSuccessor) {
+      this.defaultSuccessor = defaultSuccessor;
+   }
+
+   public ControlFlowBlock getDefaultSuccessor() {
+      return defaultSuccessor;
+   }
+
+   public ControlFlowBlock getConditionalSuccessor() {
+      return conditionalSuccessor;
+   }
+
+   public List<ControlFlowBlock> getPredecessors() {
+      return predecessors;
+   }
+
+   public void setConditionalSuccessor(ControlFlowBlock conditionalSuccessor) {
+      this.conditionalSuccessor = conditionalSuccessor;
+   }
+
+   public void removePredecessor(ControlFlowBlock block) {
+      predecessors.remove(block);
+   }
+
+   public List<Statement> getStatements() {
+      return statements;
+   }
+
+   @Override
+   public String toString() {
+      StringBuffer out = new StringBuffer();
+      out.append(label.getName() + ":" + "\n");
+      out.append("  from:");
+      for (ControlFlowBlock predecessor : predecessors) {
+         out.append(predecessor.getLabel().getName()+" ");
+      }
+      out.append("\n");
+      for (Statement statement : statements) {
+         out.append("  "+statement+"\n");
+      }
+      out.append("  to:");
+      if(defaultSuccessor!=null) {
+         out.append(defaultSuccessor.getLabel().getName());
+      }
+      out.append("\n");
+      return out.toString();
+   }
+
+   @Override
+   public boolean equals(Object o) {
+      if (this == o) return true;
+      if (o == null || getClass() != o.getClass()) return false;
+      ControlFlowBlock that = (ControlFlowBlock) o;
+      return label.equals(that.label);
+   }
+
+   @Override
+   public int hashCode() {
+      return label.hashCode();
+   }
+
+}

src/dk/camelot64/kickc/icl/ControlFlowGraph.java

@@ -0,0 +1,34 @@
+package dk.camelot64.kickc.icl;
+
+import java.util.Map;
+
+/** The control flow graph of the program.
+ * The control flow  graph is a set of connected basic blocks. */
+public class ControlFlowGraph {
+
+   private Map<Symbol, ControlFlowBlock> blocks;
+
+   private ControlFlowBlock firstBlock;
+
+   public ControlFlowGraph(Map<Symbol, ControlFlowBlock> blocks, ControlFlowBlock firstBlock) {
+      this.blocks = blocks;
+      this.firstBlock = firstBlock;
+   }
+
+   public ControlFlowBlock getBlock(Symbol symbol) {
+      return blocks.get(symbol);
+   }
+
+   public ControlFlowBlock getFirstBlock() {
+      return firstBlock;
+   }
+
+   @Override
+   public String toString() {
+      StringBuffer out = new StringBuffer();
+      for (ControlFlowBlock block : blocks.values()) {
+         out.append(block);
+      }
+      return out.toString();
+   }
+}

src/dk/camelot64/kickc/icl/LValue.java

@@ -0,0 +1,5 @@
+package dk.camelot64.kickc.icl;
+
+/** Assignable value (capable of being on the left part of an assignment)*/
+public interface LValue {
+}

src/dk/camelot64/kickc/icl/NumberParser.java

@@ -1,7 +1,7 @@
-package dk.camelot64.kickc.ssa;
+package dk.camelot64.kickc.icl;
 
 /** Parser for converting literal numbers to the corresponding Java Integer/Double */
-public class KickCNumberParser {
+public class NumberParser {
 
    public static Number parseLiteral(String literal) {
       boolean isInt = !literal.contains(".");

src/dk/camelot64/kickc/icl/Operator.java

@@ -1,11 +1,11 @@
-package dk.camelot64.kickc.ssa;
+package dk.camelot64.kickc.icl;
 
-/** SSA Form Operator. The operation performed on the rvalues in an SSA Statement. */
-public class SSAOperator {
+/** An Operator. The operation performed on the rvalues in a Statement. */
+public class Operator {
 
    private String operator;
 
-   public SSAOperator(String operator) {
+   public Operator(String operator) {
       this.operator = operator;
    }
 

src/dk/camelot64/kickc/icl/PassGenerateControlFlowGraph.java

@@ -0,0 +1,91 @@
+package dk.camelot64.kickc.icl;
+
+import java.util.ArrayList;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+
+/** Pass that generates a control flow graph for the program */
+public class PassGenerateControlFlowGraph {
+
+   public static final String FIRST_BLOCK_NAME = "@0";
+   private SymbolManager symbolManager;
+   private Map<Symbol, ControlFlowBlock> blocks;
+   private ControlFlowBlock firstBlock;
+
+   public PassGenerateControlFlowGraph(SymbolManager symbolManager) {
+      this.symbolManager = symbolManager;
+      this.blocks = new LinkedHashMap<>();
+   }
+
+   public ControlFlowGraph generate(StatementSequence sequence) {
+      this.firstBlock = getOrCreateBlock(symbolManager.newNamedJumpLabel(FIRST_BLOCK_NAME));
+      ControlFlowBlock currentBlock = this.firstBlock;
+      for (Statement statement : sequence.getStatements()) {
+         if(statement instanceof StatementJumpTarget) {
+            StatementJumpTarget statementJumpTarget = (StatementJumpTarget) statement;
+            ControlFlowBlock nextBlock = getOrCreateBlock(statementJumpTarget.getLabel());
+            currentBlock.setDefaultSuccessor(nextBlock);
+            nextBlock.addPredecessor(currentBlock);
+            currentBlock = nextBlock;
+         }  else if(statement instanceof StatementJump) {
+            StatementJump statementJump = (StatementJump) statement;
+            ControlFlowBlock jmpBlock = getOrCreateBlock(statementJump.getDestination());
+            currentBlock.setDefaultSuccessor(jmpBlock);
+            jmpBlock.addPredecessor(currentBlock);
+            ControlFlowBlock nextBlock = getOrCreateBlock(symbolManager.newIntermediateJumpLabel());
+            currentBlock = nextBlock;
+         }  else if(statement instanceof StatementConditionalJump) {
+            currentBlock.addStatement(statement);
+            StatementConditionalJump statementConditionalJump = (StatementConditionalJump) statement;
+            ControlFlowBlock jmpBlock = getOrCreateBlock(statementConditionalJump.getDestination());
+            ControlFlowBlock nextBlock = getOrCreateBlock(symbolManager.newIntermediateJumpLabel());
+            currentBlock.setDefaultSuccessor(nextBlock);
+            currentBlock.setConditionalSuccessor(jmpBlock);
+            nextBlock.addPredecessor(currentBlock);
+            jmpBlock.addPredecessor(currentBlock);
+            currentBlock = nextBlock;
+         }  else {
+            currentBlock.addStatement(statement);
+         }
+      }
+      cullEmptyBlocks();
+      return new ControlFlowGraph(blocks, firstBlock);
+   }
+
+   private void cullEmptyBlocks() {
+      List<ControlFlowBlock> remove = new ArrayList<>();
+      for (ControlFlowBlock block : blocks.values()) {
+         if(block.getStatements().isEmpty()) {
+            ControlFlowBlock successor = block.getDefaultSuccessor();
+            for (ControlFlowBlock predecessor : block.getPredecessors()) {
+               if(predecessor.getDefaultSuccessor().equals(block)) {
+                  predecessor.setDefaultSuccessor(successor);
+                  successor.addPredecessor(predecessor);
+               }
+               if(predecessor.getConditionalSuccessor().equals(block)) {
+                  predecessor.setConditionalSuccessor(successor);
+                  successor.addPredecessor(predecessor);
+               }
+            }
+            successor.removePredecessor(block);
+            remove.add(block);
+         }
+      }
+      for (ControlFlowBlock block : remove) {
+         blocks.remove(block.getLabel());
+         symbolManager.remove(block.getLabel());
+      }
+   }
+
+   private ControlFlowBlock getOrCreateBlock(Symbol label) {
+      ControlFlowBlock block = blocks.get(label);
+      if(block==null) {
+         block = new ControlFlowBlock(label);
+         blocks.put(block.getLabel(), block);
+      }
+      return block;
+   }
+
+
+}

src/dk/camelot64/kickc/icl/PassGenerateStatementSequence.java

@@ -0,0 +1,172 @@
+package dk.camelot64.kickc.icl;
+
+import dk.camelot64.kickc.parser.KickCBaseVisitor;
+import dk.camelot64.kickc.parser.KickCParser;
+import org.antlr.v4.runtime.tree.TerminalNode;
+
+/** Generates program SSA form by visiting the ANTLR4 parse tree*/
+public class PassGenerateStatementSequence extends KickCBaseVisitor<RValue> {
+
+   private SymbolManager symbolManager;
+   private StatementSequence sequence;
+
+   public PassGenerateStatementSequence() {
+      this.symbolManager = new SymbolManager();
+      this.sequence = new StatementSequence();
+   }
+
+   @Override
+   public RValue visitFile(KickCParser.FileContext ctx) {
+      this.visit(ctx.stmtSeq());
+      return null;
+   }
+
+
+   @Override
+   public RValue visitStmtSeq(KickCParser.StmtSeqContext ctx) {
+      for(int i=0; i<ctx.getChildCount(); i++) {
+         this.visit(ctx.stmt(i));
+      }
+      return null;
+   }
+
+   @Override
+   public RValue visitStmtBlock(KickCParser.StmtBlockContext ctx) {
+      this.visit(ctx.stmtSeq());
+      return null;
+   }
+
+   @Override
+   public RValue visitStmtExpr(KickCParser.StmtExprContext ctx) {
+      this.visit(ctx.expr());
+      return null;
+   }
+
+   @Override
+   public RValue visitStmtIfElse(KickCParser.StmtIfElseContext ctx) {
+      RValue rValue = this.visit(ctx.expr());
+      Symbol ifJumpLabel = symbolManager.newIntermediateJumpLabel();
+      Symbol elseJumpLabel = symbolManager.newIntermediateJumpLabel();
+      Statement ifJmpStmt = new StatementConditionalJump(rValue, ifJumpLabel);
+      sequence.addStatement(ifJmpStmt);
+      Statement elseJmpStmt = new StatementJump(elseJumpLabel);
+      sequence.addStatement(elseJmpStmt);
+      StatementJumpTarget ifJumpTarget = new StatementJumpTarget(ifJumpLabel);
+      sequence.addStatement(ifJumpTarget);
+      this.visit(ctx.stmt(0));
+      KickCParser.StmtContext elseStmt = ctx.stmt(1);
+      if(elseStmt!=null) {
+         Symbol endJumpLabel = symbolManager.newIntermediateJumpLabel();
+         Statement endJmpStmt = new StatementJump(endJumpLabel);
+         sequence.addStatement(endJmpStmt);
+         StatementJumpTarget elseJumpTarget = new StatementJumpTarget(elseJumpLabel);
+         sequence.addStatement(elseJumpTarget);
+         this.visit(elseStmt);
+         StatementJumpTarget endJumpTarget = new StatementJumpTarget(endJumpLabel);
+         sequence.addStatement(endJumpTarget);
+      }  else {
+         StatementJumpTarget elseJumpTarget = new StatementJumpTarget(elseJumpLabel);
+         sequence.addStatement(elseJumpTarget);
+      }
+      return null;
+   }
+
+   @Override
+   public RValue visitStmtWhile(KickCParser.StmtWhileContext ctx) {
+      Symbol beginJumpLabel = symbolManager.newIntermediateJumpLabel();
+      Symbol doJumpLabel = symbolManager.newIntermediateJumpLabel();
+      Symbol endJumpLabel = symbolManager.newIntermediateJumpLabel();
+      StatementJumpTarget beginJumpTarget = new StatementJumpTarget(beginJumpLabel);
+      sequence.addStatement(beginJumpTarget);
+      RValue rValue = this.visit(ctx.expr());
+      Statement doJmpStmt = new StatementConditionalJump(rValue, doJumpLabel);
+      sequence.addStatement(doJmpStmt);
+      Statement endJmpStmt = new StatementJump(endJumpLabel);
+      sequence.addStatement(endJmpStmt);
+      StatementJumpTarget doJumpTarget = new StatementJumpTarget(doJumpLabel);
+      sequence.addStatement(doJumpTarget);
+      this.visit(ctx.stmt());
+      Statement beginJmpStmt = new StatementJump(beginJumpLabel);
+      sequence.addStatement(beginJmpStmt);
+      StatementJumpTarget endJumpTarget = new StatementJumpTarget(endJumpLabel);
+      sequence.addStatement(endJumpTarget);
+      return null;
+   }
+
+   @Override
+   public RValue visitStmtAssignment(KickCParser.StmtAssignmentContext ctx) {
+      if(ctx.TYPE()!=null) {
+         symbolManager.newVariableDeclaration(ctx.NAME().getText(), ctx.TYPE().getText());
+      }
+      if(ctx.expr()!=null) {
+         RValue rValue = this.visit(ctx.expr());
+         Symbol variable = symbolManager.newVariableAssignment(ctx.NAME().getText());
+         Statement stmt = new StatementAssignment(variable, rValue);
+         sequence.addStatement(stmt);
+      }
+      return null;
+   }
+
+   @Override
+   public RValue visitExprNumber(KickCParser.ExprNumberContext ctx) {
+      Number number = NumberParser.parseLiteral(ctx.getText());
+      if(number instanceof Integer)  {
+         return new ConstantInteger((Integer) number);
+      } else {
+         return new ConstantDouble((Double) number);
+      }
+   }
+
+   @Override
+   public RValue visitExprString(KickCParser.ExprStringContext ctx) {
+      return new ConstantString(ctx.getText());
+   }
+
+   @Override
+   public RValue visitExprBool(KickCParser.ExprBoolContext ctx) {
+      String bool = ctx.getText();
+      return new ConstantBool(Boolean.valueOf(bool));
+   }
+
+
+   @Override
+   public RValue visitExprBinary(KickCParser.ExprBinaryContext ctx) {
+      RValue left = this.visit(ctx.expr(0));
+      RValue right = this.visit(ctx.expr(1));
+      String op = ((TerminalNode)ctx.getChild(1)).getSymbol().getText();
+      Operator operator = new Operator(op);
+      Symbol tmpVar = symbolManager.newIntermediateAssignment();
+      Statement stmt = new StatementAssignment(tmpVar, left, operator, right);
+      sequence.addStatement(stmt);
+      return tmpVar;
+   }
+
+   @Override
+   public RValue visitExprUnary(KickCParser.ExprUnaryContext ctx) {
+      RValue child = this.visit(ctx.expr());
+      String op = ((TerminalNode)ctx.getChild(0)).getSymbol().getText();
+      Operator operator = new Operator(op);
+      Symbol tmpVar = symbolManager.newIntermediateAssignment();
+      Statement stmt = new StatementAssignment(tmpVar, operator, child);
+      sequence.addStatement(stmt);
+      return tmpVar;
+   }
+
+   @Override
+   public RValue visitExprPar(KickCParser.ExprParContext ctx) {
+      return this.visit(ctx.expr());
+   }
+
+   @Override
+   public RValue visitExprId(KickCParser.ExprIdContext ctx) {
+      return symbolManager.newVariableUsage(ctx.NAME().getText());
+   }
+
+   public StatementSequence getSequence() {
+      return sequence;
+   }
+
+   public SymbolManager getSymbols() {
+      return this.symbolManager;
+   }
+}

src/dk/camelot64/kickc/icl/PassTypeInference.java

@@ -1,21 +1,21 @@
-package dk.camelot64.kickc.ssa;
+package dk.camelot64.kickc.icl;
 
 /**
  * Pass through the SSA statements inferring types of unresolved variables.
  */
 public class PassTypeInference {
 
-   public void inferTypes(SSASequence sequence, SymbolManager symbols) {
-      for (SSAStatement statement : sequence.getStatements()) {
-         if (statement instanceof SSAStatementAssignment) {
-            SSAStatementAssignment assignment = (SSAStatementAssignment) statement;
+   public void inferTypes(StatementSequence sequence, SymbolManager symbols) {
+      for (Statement statement : sequence.getStatements()) {
+         if (statement instanceof StatementAssignment) {
+            StatementAssignment assignment = (StatementAssignment) statement;
             Symbol symbol = (Symbol) assignment.getlValue();
             if (SymbolType.VAR.equals(symbol.getType())) {
                // Unresolved symbol - perform inference
-               SSAOperator operator = assignment.getOperator();
+               Operator operator = assignment.getOperator();
                if (operator == null || assignment.getRValue1() == null) {
                   // Copy operation or Unary operation
-                  SSARValue rValue = assignment.getRValue2();
+                  RValue rValue = assignment.getRValue2();
                   SymbolType type = inferType(rValue);
                   symbol.setInferredType(type);
                } else {
@@ -30,7 +30,7 @@ public class PassTypeInference {
       }
    }
 
-   private SymbolType inferType(SymbolType type1, SSAOperator operator, SymbolType type2) {
+   private SymbolType inferType(SymbolType type1, Operator operator, SymbolType type2) {
       String op = operator.getOperator();
       switch (op) {
          case "==":
@@ -61,21 +61,21 @@ public class PassTypeInference {
       }
    }
 
-   private SymbolType inferType(SSARValue rValue) {
+   private SymbolType inferType(RValue rValue) {
       SymbolType type = SymbolType.VAR;
       if (rValue instanceof Symbol) {
          Symbol rSymbol = (Symbol) rValue;
          type = rSymbol.getType();
-      } else if (rValue instanceof SSAConstantInteger) {
-         SSAConstantInteger rInt = (SSAConstantInteger) rValue;
+      } else if (rValue instanceof ConstantInteger) {
+         ConstantInteger rInt = (ConstantInteger) rValue;
          if (rInt.getNumber() < 256) {
             type = SymbolType.BYTE;
          } else {
             type = SymbolType.WORD;
          }
-      } else if (rValue instanceof SSAConstantString) {
+      } else if (rValue instanceof ConstantString) {
          type = SymbolType.STRING;
-      } else if (rValue instanceof SSAConstantBool) {
+      } else if (rValue instanceof ConstantBool) {
          type = SymbolType.BOOLEAN;
       }
       return type;

src/dk/camelot64/kickc/icl/RValue.java

@@ -0,0 +1,5 @@
+package dk.camelot64.kickc.icl;
+
+/** A value usable as part of a calculation (ib the right side of an assignment)*/
+public interface RValue {
+}

src/dk/camelot64/kickc/icl/Statement.java

@@ -1,10 +1,10 @@
-package dk.camelot64.kickc.ssa;
+package dk.camelot64.kickc.icl;
 
 /**
  * Single Static Assignment Form Statement.
  * Intermediate form used for compiler optimization.
  */
-public interface SSAStatement extends SSAFragment {
+public interface Statement {
 
 
 }

src/dk/camelot64/kickc/icl/StatementAssignment.java

@@ -1,4 +1,4 @@
-package dk.camelot64.kickc.ssa;
+package dk.camelot64.kickc.icl;
 
 /**
  * Single Static Assignment Form Statement.
@@ -8,56 +8,56 @@ package dk.camelot64.kickc.ssa;
  * <br>
  * <i> lValue := rValue1 &lt;operator&gt; rValue2 </i>
  */
-public class SSAStatementAssignment implements SSAStatement {
+public class StatementAssignment implements Statement {
 
    /** The variable being assigned a value by the statement. */
-   private SSALValue lValue;
+   private LValue lValue;
 
-   private SSARValue rValue1;
-   private SSAOperator operator;
-   private SSARValue rValue2;
+   private RValue rValue1;
+   private Operator operator;
+   private RValue rValue2;
 
-   public SSAStatementAssignment(SSALValue lValue, SSARValue rValue2) {
+   public StatementAssignment(LValue lValue, RValue rValue2) {
       this.lValue = lValue;
       this.rValue1 = null;
       this.operator = null;
       this.rValue2 = rValue2;
    }
 
-   public SSAStatementAssignment(SSALValue lValue, SSARValue rValue1, SSAOperator operator, SSARValue rValue2) {
+   public StatementAssignment(LValue lValue, RValue rValue1, Operator operator, RValue rValue2) {
       this.lValue = lValue;
       this.rValue1 = rValue1;
       this.operator = operator;
       this.rValue2 = rValue2;
    }
 
-   public SSAStatementAssignment(SSALValue lValue, SSAOperator operator, SSARValue rValue2) {
+   public StatementAssignment(LValue lValue, Operator operator, RValue rValue2) {
       this.lValue = lValue;
       this.rValue1 = null;
       this.operator = operator;
       this.rValue2 = rValue2;
    }
 
-   public SSALValue getlValue() {
+   public LValue getlValue() {
       return lValue;
    }
 
-   public SSARValue getRValue1() {
+   public RValue getRValue1() {
       return rValue1;
    }
 
-   public SSAOperator getOperator() {
+   public Operator getOperator() {
       return operator;
    }
 
-   public SSARValue getRValue2() {
+   public RValue getRValue2() {
       return rValue2;
    }
 
    @Override
    public String toString() {
       return
-               "  "+
+
                   lValue + " ← " +
                   (rValue1==null?"":rValue1+" ") +
                   (operator==null?"":operator+" ") +

src/dk/camelot64/kickc/icl/StatementConditionalJump.java

@@ -0,0 +1,31 @@
+package dk.camelot64.kickc.icl;
+
+/**
+ * Intermediate Compiler Form Statement with a conditional jump.
+ * Intermediate form used for compiler optimization.
+ * <br>
+ * <i> if ( Y<sub>j</sub> ) goto XX </i>
+ */
+public class StatementConditionalJump implements Statement {
+
+   private RValue condition;
+   private Symbol destination;
+
+   public StatementConditionalJump(RValue condition, Symbol destination) {
+      this.condition = condition;
+      this.destination = destination;
+   }
+
+   public RValue getCondition() {
+      return condition;
+   }
+
+   public Symbol getDestination() {
+      return destination;
+   }
+
+   @Override
+   public String toString() {
+      return "if("+condition+") goto "+destination.getName();
+   }
+}

src/dk/camelot64/kickc/icl/StatementJump.java

@@ -1,4 +1,4 @@
-package dk.camelot64.kickc.ssa;
+package dk.camelot64.kickc.icl;
 
 /**
  * Single Static Assignment Form Statement unconditional jump.
@@ -6,20 +6,20 @@ package dk.camelot64.kickc.ssa;
  * <br>
  * <i> goto XX </i>
  */
-public class SSAStatementJump implements SSAStatement {
+public class StatementJump implements Statement {
 
-   private SSAJumpLabel destination;
+   private Symbol destination;
 
-   public SSAStatementJump(SSAJumpLabel destination) {
+   public StatementJump(Symbol destination) {
       this.destination = destination;
    }
 
-   public SSAJumpLabel getDestination() {
+   public Symbol getDestination() {
       return destination;
    }
 
    @Override
    public String toString() {
-      return "  "+"goto "+destination;
+      return "goto "+destination.getName();
    }
 }

src/dk/camelot64/kickc/icl/StatementJumpTarget.java

@@ -0,0 +1,24 @@
+package dk.camelot64.kickc.icl;
+
+/**
+ * Single Static Assignment Form Statement Jump target.
+ */
+public class StatementJumpTarget implements Statement {
+
+   private Symbol label;
+
+   public StatementJumpTarget(Symbol label) {
+      this.label = label;
+   }
+
+   public Symbol getLabel() {
+      return label;
+   }
+
+   @Override
+   public String toString() {
+      return label+":";
+   }
+
+
+}

src/dk/camelot64/kickc/icl/StatementSequence.java

@@ -0,0 +1,34 @@
+package dk.camelot64.kickc.icl;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/** A sequence of Statements */
+public class StatementSequence {
+
+   private List<Statement> statements;
+
+   public StatementSequence() {
+      this.statements = new ArrayList<>();
+   }
+
+   public void addStatement(Statement statement) {
+      this.statements.add(statement);
+   }
+
+   @Override
+   public String toString() {
+      StringBuffer out = new StringBuffer();
+      for (Statement statement : statements) {
+         if(!(statement instanceof StatementJumpTarget)) {
+             out.append("  ");
+         }
+         out.append(statement.toString()+"\n");
+      }
+      return out.toString();
+   }
+
+   public List<Statement> getStatements() {
+      return statements;
+   }
+}

src/dk/camelot64/kickc/icl/Symbol.java

@@ -0,0 +1,62 @@
+package dk.camelot64.kickc.icl;
+
+/** A Symbol (variable, jump label, etc.) */
+public class Symbol implements RValue, LValue {
+
+   private String name;
+
+   private SymbolType type;
+
+   private boolean intermediate;
+
+   private boolean inferredType;
+
+   public Symbol(String name, SymbolType type, boolean intermediate) {
+      this.name = name;
+      this.type = type;
+      this.intermediate = intermediate;
+      this.inferredType = false;
+   }
+
+   public String getName() {
+      return name;
+   }
+
+   public SymbolType getType() {
+      return type;
+   }
+
+   public void setInferredType(SymbolType type) {
+      this.type = type;
+      this.inferredType = true;
+   }
+
+   public boolean isIntermediate() {
+      return intermediate;
+   }
+
+   @Override
+   public String toString() {
+      return "("+name + ": " + type.getTypeName() + (inferredType ?"*":"") + ")";
+   }
+
+   @Override
+   public boolean equals(Object o) {
+      if (this == o) return true;
+      if (o == null || getClass() != o.getClass()) return false;
+      Symbol symbol = (Symbol) o;
+      if (intermediate != symbol.intermediate) return false;
+      if (inferredType != symbol.inferredType) return false;
+      if (!name.equals(symbol.name)) return false;
+      return type == symbol.type;
+   }
+
+   @Override
+   public int hashCode() {
+      int result = name.hashCode();
+      result = 31 * result + (type != null ? type.hashCode() : 0);
+      result = 31 * result + (intermediate ? 1 : 0);
+      result = 31 * result + (inferredType ? 1 : 0);
+      return result;
+   }
+}

src/dk/camelot64/kickc/icl/SymbolManager.java

@@ -1,4 +1,4 @@
-package dk.camelot64.kickc.ssa;
+package dk.camelot64.kickc.icl;
 
 import java.util.LinkedHashMap;
 import java.util.Map;
@@ -11,7 +11,7 @@ public class SymbolManager {
    private Map<String, Symbol> symbols;
 
    private int intermediateVarCount = 0;
-   private int intermediateLabelCount = 0;
+   private int intermediateLabelCount = 1;
 
    public SymbolManager() {
       this.symbols = new LinkedHashMap<>();
@@ -45,15 +45,15 @@ public class SymbolManager {
       return symbol;
    }
 
-   public SSAJumpLabel newNamedJumpLabel(String name) {
+   public Symbol newNamedJumpLabel(String name) {
       Symbol symbol = addSymbol(name, SymbolType.LABEL, false);
-      return new SSAJumpLabel(name);
+      return symbol;
    }
 
-   public SSAJumpLabel newIntermediateJumpLabel() {
+   public Symbol newIntermediateJumpLabel() {
       String name = "@"+   intermediateLabelCount++;
-      addSymbol(name, SymbolType.LABEL, true);
-      return new SSAJumpLabel(name);
+      Symbol symbol = addSymbol(name, SymbolType.LABEL, true);
+      return symbol;
    }
 
    @Override
@@ -65,4 +65,8 @@ public class SymbolManager {
       }
       return out.toString();
    }
+
+   public void remove(Symbol symbol) {
+      symbols.remove(symbol.getName());
+   }
 }

src/dk/camelot64/kickc/icl/SymbolType.java

@@ -1,4 +1,4 @@
-package dk.camelot64.kickc.ssa;
+package dk.camelot64.kickc.icl;
 
 /** Symbol Types */
 public enum SymbolType {

src/dk/camelot64/kickc/ssa/GenerateSSA.java

@@ -1,172 +0,0 @@
-package dk.camelot64.kickc.ssa;
-
-import dk.camelot64.kickc.parser.KickCBaseVisitor;
-import dk.camelot64.kickc.parser.KickCParser;
-import org.antlr.v4.runtime.tree.TerminalNode;
-
-/** Generates program SSA form by visiting the ANTLR4 parse tree*/
-public class GenerateSSA extends KickCBaseVisitor<SSARValue> {
-
-   private SymbolManager symbolManager;
-   private SSASequence sequence;
-
-   public GenerateSSA() {
-      this.symbolManager = new SymbolManager();
-      this.sequence = new SSASequence();
-   }
-
-   @Override
-   public SSARValue visitFile(KickCParser.FileContext ctx) {
-      this.visit(ctx.stmtSeq());
-      return null;
-   }
-
-
-   @Override
-   public SSARValue visitStmtSeq(KickCParser.StmtSeqContext ctx) {
-      for(int i=0; i<ctx.getChildCount(); i++) {
-         this.visit(ctx.stmt(i));
-      }
-      return null;
-   }
-
-   @Override
-   public SSARValue visitStmtBlock(KickCParser.StmtBlockContext ctx) {
-      this.visit(ctx.stmtSeq());
-      return null;
-   }
-
-   @Override
-   public SSARValue visitStmtExpr(KickCParser.StmtExprContext ctx) {
-      this.visit(ctx.expr());
-      return null;
-   }
-
-   @Override
-   public SSARValue visitStmtIfElse(KickCParser.StmtIfElseContext ctx) {
-      SSARValue rValue = this.visit(ctx.expr());
-      SSAJumpLabel ifJumpLabel = symbolManager.newIntermediateJumpLabel();
-      SSAJumpLabel elseJumpLabel = symbolManager.newIntermediateJumpLabel();
-      SSAStatement ifJmpStmt = new SSAStatementConditionalJump(rValue, ifJumpLabel);
-      sequence.addStatement(ifJmpStmt);
-      SSAStatement elseJmpStmt = new SSAStatementJump(elseJumpLabel);
-      sequence.addStatement(elseJmpStmt);
-      SSAStatementJumpTarget ifJumpTarget = new SSAStatementJumpTarget(ifJumpLabel);
-      sequence.addStatement(ifJumpTarget);
-      this.visit(ctx.stmt(0));
-      KickCParser.StmtContext elseStmt = ctx.stmt(1);
-      if(elseStmt!=null) {
-         SSAJumpLabel endJumpLabel = symbolManager.newIntermediateJumpLabel();
-         SSAStatement endJmpStmt = new SSAStatementJump(endJumpLabel);
-         sequence.addStatement(endJmpStmt);
-         SSAStatementJumpTarget elseJumpTarget = new SSAStatementJumpTarget(elseJumpLabel);
-         sequence.addStatement(elseJumpTarget);
-         this.visit(elseStmt);
-         SSAStatementJumpTarget endJumpTarget = new SSAStatementJumpTarget(endJumpLabel);
-         sequence.addStatement(endJumpTarget);
-      }  else {
-         SSAStatementJumpTarget elseJumpTarget = new SSAStatementJumpTarget(elseJumpLabel);
-         sequence.addStatement(elseJumpTarget);
-      }
-      return null;
-   }
-
-   @Override
-   public SSARValue visitStmtWhile(KickCParser.StmtWhileContext ctx) {
-      SSAJumpLabel beginJumpLabel = symbolManager.newIntermediateJumpLabel();
-      SSAJumpLabel doJumpLabel = symbolManager.newIntermediateJumpLabel();
-      SSAJumpLabel endJumpLabel = symbolManager.newIntermediateJumpLabel();
-      SSAStatementJumpTarget beginJumpTarget = new SSAStatementJumpTarget(beginJumpLabel);
-      sequence.addStatement(beginJumpTarget);
-      SSARValue rValue = this.visit(ctx.expr());
-      SSAStatement doJmpStmt = new SSAStatementConditionalJump(rValue, doJumpLabel);
-      sequence.addStatement(doJmpStmt);
-      SSAStatement endJmpStmt = new SSAStatementJump(endJumpLabel);
-      sequence.addStatement(endJmpStmt);
-      SSAStatementJumpTarget doJumpTarget = new SSAStatementJumpTarget(doJumpLabel);
-      sequence.addStatement(doJumpTarget);
-      this.visit(ctx.stmt());
-      SSAStatement beginJmpStmt = new SSAStatementJump(beginJumpLabel);
-      sequence.addStatement(beginJmpStmt);
-      SSAStatementJumpTarget endJumpTarget = new SSAStatementJumpTarget(endJumpLabel);
-      sequence.addStatement(endJumpTarget);
-      return null;
-   }
-
-   @Override
-   public SSARValue visitStmtAssignment(KickCParser.StmtAssignmentContext ctx) {
-      if(ctx.TYPE()!=null) {
-         symbolManager.newVariableDeclaration(ctx.NAME().getText(), ctx.TYPE().getText());
-      }
-      if(ctx.expr()!=null) {
-         SSARValue rValue = this.visit(ctx.expr());
-         Symbol variable = symbolManager.newVariableAssignment(ctx.NAME().getText());
-         SSAStatement stmt = new SSAStatementAssignment(variable, rValue);
-         sequence.addStatement(stmt);
-      }
-      return null;
-   }
-
-   @Override
-   public SSARValue visitExprNumber(KickCParser.ExprNumberContext ctx) {
-      Number number = KickCNumberParser.parseLiteral(ctx.getText());
-      if(number instanceof Integer)  {
-         return new SSAConstantInteger((Integer) number);
-      } else {
-         return new SSAConstantDouble((Double) number);
-      }
-   }
-
-   @Override
-   public SSARValue visitExprString(KickCParser.ExprStringContext ctx) {
-      return new SSAConstantString(ctx.getText());
-   }
-
-   @Override
-   public SSARValue visitExprBool(KickCParser.ExprBoolContext ctx) {
-      String bool = ctx.getText();
-      return new SSAConstantBool(Boolean.valueOf(bool));
-   }
-
-
-   @Override
-   public SSARValue visitExprBinary(KickCParser.ExprBinaryContext ctx) {
-      SSARValue left = this.visit(ctx.expr(0));
-      SSARValue right = this.visit(ctx.expr(1));
-      String op = ((TerminalNode)ctx.getChild(1)).getSymbol().getText();
-      SSAOperator operator = new SSAOperator(op);
-      Symbol tmpVar = symbolManager.newIntermediateAssignment();
-      SSAStatement stmt = new SSAStatementAssignment(tmpVar, left, operator, right);
-      sequence.addStatement(stmt);
-      return tmpVar;
-   }
-
-   @Override
-   public SSARValue visitExprUnary(KickCParser.ExprUnaryContext ctx) {
-      SSARValue child = this.visit(ctx.expr());
-      String op = ((TerminalNode)ctx.getChild(0)).getSymbol().getText();
-      SSAOperator operator = new SSAOperator(op);
-      Symbol tmpVar = symbolManager.newIntermediateAssignment();
-      SSAStatement stmt = new SSAStatementAssignment(tmpVar, operator, child);
-      sequence.addStatement(stmt);
-      return tmpVar;
-   }
-
-   @Override
-   public SSARValue visitExprPar(KickCParser.ExprParContext ctx) {
-      return this.visit(ctx.expr());
-   }
-
-   @Override
-   public SSARValue visitExprId(KickCParser.ExprIdContext ctx) {
-      return symbolManager.newVariableUsage(ctx.NAME().getText());
-   }
-
-   public SSASequence getSequence() {
-      return sequence;
-   }
-
-   public SymbolManager getSymbols() {
-      return this.symbolManager;
-   }
-}

src/dk/camelot64/kickc/ssa/SSABasicBlock.java

@@ -1,25 +0,0 @@
-package dk.camelot64.kickc.ssa;
-
-import java.util.ArrayList;
-import java.util.List;
-
-/** A sequence of SSA statements */
-public class SSABasicBlock {
-
-   List<SSAStatement> statements;
-
-   public SSABasicBlock() {
-      this.statements = new ArrayList<>();
-   }
-
-   public void addStatement(SSAStatement statement) {
-      this.statements.add(statement);
-   }
-
-   @Override
-   public String toString() {
-      return "SSABasicBlock{" +
-            "statements=" + statements +
-            '}';
-   }
-}

src/dk/camelot64/kickc/ssa/SSAConstant.java

@@ -1,7 +0,0 @@
-package dk.camelot64.kickc.ssa;
-
-/** SSA form constant value */
-public interface SSAConstant extends SSARValue, SSAFragment {
-
-
-}

src/dk/camelot64/kickc/ssa/SSAFragment.java

@@ -1,7 +0,0 @@
-package dk.camelot64.kickc.ssa;
-
-/**
- * Any SSA Form fragment resulting from translating a part of the parse tree
- */
-public interface SSAFragment {
-}

src/dk/camelot64/kickc/ssa/SSAJumpLabel.java

@@ -1,16 +0,0 @@
-package dk.camelot64.kickc.ssa;
-
-/** A label representing a target of a jump in SSA code */
-public class SSAJumpLabel {
-
-   private String name;
-
-   public SSAJumpLabel(String name) {
-      this.name = name;
-   }
-
-   @Override
-   public String toString() {
-      return name;
-   }
-}

src/dk/camelot64/kickc/ssa/SSALValue.java

@@ -1,5 +0,0 @@
-package dk.camelot64.kickc.ssa;
-
-/** Left value in SSA Form */
-public interface SSALValue {
-}

src/dk/camelot64/kickc/ssa/SSARValue.java

@@ -1,5 +0,0 @@
-package dk.camelot64.kickc.ssa;
-
-/** Right value in SSA FORM  */
-public interface SSARValue {
-}

src/dk/camelot64/kickc/ssa/SSASequence.java

@@ -1,33 +0,0 @@
-package dk.camelot64.kickc.ssa;
-
-import java.util.ArrayList;
-import java.util.List;
-
-/**
- * A sequence of SSA Statements
- */
-public class SSASequence {
-
-   List<SSAStatement> statements;
-
-   public SSASequence() {
-      this.statements = new ArrayList<>();
-   }
-
-   public void addStatement(SSAStatement statement) {
-      this.statements.add(statement);
-   }
-
-   @Override
-   public String toString() {
-      StringBuffer out = new StringBuffer();
-      for (SSAStatement statement : statements) {
-         out.append(statement.toString()+"\n");
-      }
-      return out.toString();
-   }
-
-   public List<SSAStatement> getStatements() {
-      return statements;
-   }
-}

src/dk/camelot64/kickc/ssa/SSAStatementConditionalJump.java

@@ -1,31 +0,0 @@
-package dk.camelot64.kickc.ssa;
-
-/**
- * Single Static Assignment Form Statement with a conditional jump.
- * Intermediate form used for compiler optimization.
- * <br>
- * <i> if ( Y<sub>j</sub> ) goto XX </i>
- */
-public class SSAStatementConditionalJump implements SSAStatement {
-
-   private SSARValue condition;
-   private SSAJumpLabel destination;
-
-   public SSAStatementConditionalJump(SSARValue condition, SSAJumpLabel destination) {
-      this.condition = condition;
-      this.destination = destination;
-   }
-
-   public SSARValue getCondition() {
-      return condition;
-   }
-
-   public SSAJumpLabel getDestination() {
-      return destination;
-   }
-
-   @Override
-   public String toString() {
-      return "  "+"if("+condition+") goto "+destination;
-   }
-}

src/dk/camelot64/kickc/ssa/SSAStatementJumpTarget.java

@@ -1,24 +0,0 @@
-package dk.camelot64.kickc.ssa;
-
-/**
- * Single Static Assignment Form Statement Jump target.
- */
-public class SSAStatementJumpTarget implements SSAStatement {
-
-   private SSAJumpLabel label;
-
-   public SSAStatementJumpTarget(SSAJumpLabel label) {
-      this.label = label;
-   }
-
-   public SSAJumpLabel getLabel() {
-      return label;
-   }
-
-   @Override
-   public String toString() {
-      return label+":";
-   }
-
-
-}

src/dk/camelot64/kickc/ssa/SSAVariable.java

@@ -1,40 +0,0 @@
-package dk.camelot64.kickc.ssa;
-
-/** An SSA form Variable. SSA form variables come in different flavors:
- * <ul>
- *    <li>Each potential modification of a language variable becomes a separate versioned SSA variable.</li>
- *    <li>Expressions are broken into separate SSA statements, each defining a new temporary/intermediate variable.</li>
- * </ul>
- *
- * Named variables are initially created without serials. These are first added after the basic control blocks have been defined.
- *
- * */
-public class SSAVariable implements SSARValue, SSALValue, SSAFragment {
-
-   private String name;
-
-   private Integer serial;
-
-   public SSAVariable(String name) {
-      this.name = name;
-      this.serial = null;
-   }
-
-   public SSAVariable(String name, int serial) {
-      this.name = name;
-      this.serial = serial;
-   }
-
-   public String getName() {
-      return name;
-   }
-
-   public int getSerial() {
-      return serial;
-   }
-
-   @Override
-   public String toString() {
-      return name + (serial==null?"":"_"+serial);
-   }
-}

src/dk/camelot64/kickc/ssa/Symbol.java

@@ -1,43 +0,0 @@
-package dk.camelot64.kickc.ssa;
-
-/** A Symbol (variable, jump label, etc.) */
-public class Symbol implements SSARValue, SSALValue, SSAFragment {
-
-   private String name;
-
-   private SymbolType type;
-
-   private boolean intermediate;
-
-   private boolean inferredType;
-
-   public Symbol(String name, SymbolType type, boolean intermediate) {
-      this.name = name;
-      this.type = type;
-      this.intermediate = intermediate;
-      this.inferredType = false;
-   }
-
-   public String getName() {
-      return name;
-   }
-
-   public SymbolType getType() {
-      return type;
-   }
-
-   public void setInferredType(SymbolType type) {
-      this.type = type;
-      this.inferredType = true;
-   }
-
-   public boolean isIntermediate() {
-      return intermediate;
-   }
-
-   @Override
-   public String toString() {
-      return "("+name + (intermediate?"*":"") + ": " + type.getTypeName() + (inferredType ?"*":"") + ")";
-   }
-
-}

src/dk/camelot64/kickc/test/main.java

@@ -1,10 +1,11 @@
 package dk.camelot64.kickc.test;
 
+import dk.camelot64.kickc.icl.ControlFlowGraph;
+import dk.camelot64.kickc.icl.PassGenerateControlFlowGraph;
 import dk.camelot64.kickc.parser.KickCLexer;
 import dk.camelot64.kickc.parser.KickCParser;
-import dk.camelot64.kickc.ssa.GenerateSSA;
-import dk.camelot64.kickc.ssa.PassTypeInference;
-import dk.camelot64.kickc.ssa.SSASequence;
+import dk.camelot64.kickc.icl.PassGenerateStatementSequence;
+import dk.camelot64.kickc.icl.PassTypeInference;
 import org.antlr.v4.runtime.CharStream;
 import org.antlr.v4.runtime.CharStreams;
 import org.antlr.v4.runtime.CommonTokenStream;
@@ -20,16 +21,18 @@ public class main {
       KickCParser parser = new KickCParser(new CommonTokenStream(lexer));
       parser.setBuildParseTree(true);
       KickCParser.FileContext file = parser.file();
-      GenerateSSA ev = new GenerateSSA();
-      ev.visit(file);
-
-      PassTypeInference passTypeInference = new PassTypeInference();
-      passTypeInference.inferTypes(ev.getSequence(), ev.getSymbols());
-
-      System.out.println("PROGRAM");
-      System.out.println(ev.getSequence().toString());
+      PassGenerateStatementSequence passGenerateStatementSequence = new PassGenerateStatementSequence();
+      passGenerateStatementSequence.visit(file);
+      new PassTypeInference().inferTypes(passGenerateStatementSequence.getSequence(), passGenerateStatementSequence.getSymbols());
+      PassGenerateControlFlowGraph passGenerateControlFlowGraph = new PassGenerateControlFlowGraph(passGenerateStatementSequence.getSymbols());
+      ControlFlowGraph controlFlowGraph = passGenerateControlFlowGraph.generate(passGenerateStatementSequence.getSequence());
       System.out.println("SYMBOLS");
-      System.out.println(ev.getSymbols().toString());
+      System.out.println(passGenerateStatementSequence.getSymbols().toString());
+      System.out.println("PROGRAM");
+      System.out.println(passGenerateStatementSequence.getSequence().toString());
+      System.out.println("CONTROL FLOW GRAPH");
+      System.out.println(controlFlowGraph.toString());
+
    }
 
 }