Code generation (#20)

Co-authored-by: geno <gabrigeno@gmail>
Co-authored-by: Santo Cariotti <santo@dcariotti.me>

1 files changed, 27 insertions, 10 deletions

diff --git a/src/ast/nodes/FuncdefNode.java b/src/ast/nodes/FuncdefNode.java
index 91231cc..c2671b2 100644
--- a/src/ast/nodes/FuncdefNode.java
+++ b/src/ast/nodes/FuncdefNode.java
@@ -8,6 +8,7 @@ import semanticanalysis.SemanticError;
 import semanticanalysis.SymbolTable;
 import ast.types.*;
 import org.antlr.v4.runtime.tree.TerminalNode;
+import codegen.Label;
 
 /**
  * Node for the `funcdef` statement of the grammar.
@@ -17,38 +18,45 @@ public class FuncdefNode implements Node {
     private final TerminalNode name;
     private final Node paramlist;
     private final Node block;
+    private final String funLabel;
 
     public FuncdefNode(TerminalNode name, Node paramlist, Node block) {
         this.name = name;
         this.paramlist = paramlist;
         this.block = block;
+        this.funLabel = Label.newFun("FUN");
     }
 
     @Override
-    public ArrayList<SemanticError> checkSemantics(SymbolTable ST, int _nesting) {
+    public ArrayList<SemanticError> checkSemantics(SymbolTable ST, int _nesting, FunctionType ft) {
         ArrayList<SemanticError> errors = new ArrayList<>();
-        int paramNumber = ((ParamlistNode) paramlist).getParamNumber();
+        int paramNumber = 0;
+        if (paramlist != null) {
+            paramNumber = ((ParamlistNode) paramlist).getParamNumber();
+        }
         Type returnType = this.block.typeCheck();
-        FunctionType ft = new FunctionType(paramNumber, returnType);
+        FunctionType newFt = new FunctionType(paramNumber, returnType, funLabel);
 
-        ST.insert(this.name.toString(), ft, _nesting, "");
+        String funName = this.name.toString();
+        ST.insert(funName, newFt, _nesting, "");
 
         HashMap<String, STentry> HM = new HashMap<>();
 
         ST.add(HM);
 
-        ST.insert(this.name.toString(), ft, _nesting + 1, "");
+        ST.insert(funName, newFt, _nesting + 1, "");
+        ST.decreaseOffset();
 
         if (paramlist != null) {
-            errors.addAll(paramlist.checkSemantics(ST, _nesting + 1));
+            errors.addAll(paramlist.checkSemantics(ST, _nesting + 1, newFt));
         }
 
-        // TODO: think to the fucking offset
         // Offset is increased for the possible return value
-        ST.increaseoffset();
+        ST.increaseOffset();
 
-        errors.addAll(block.checkSemantics(ST, _nesting + 1));
+        errors.addAll(block.checkSemantics(ST, _nesting + 1, newFt));
 
+        // return to the outer block
         ST.remove();
 
         return errors;
@@ -60,9 +68,18 @@ public class FuncdefNode implements Node {
         return new VoidType();
     }
 
-    // TODO: code generation for funcdef
+    /**
+     * Taken from slide 56 of CodeGeneration.pdf
+     */
     @Override
     public String codeGeneration() {
+        String blockS = block.codeGeneration();
+        // The "return" which fix the RA is inside the block
+        String funS = funLabel + ":\n" +
+                "pushr RA\n" +
+                blockS;
+
+        Label.addFunDef(funS);
         return "";
     }