Add codegen for entrypoint method & fixes

task1/CodegenImpl.java

@@ -4,7 +4,19 @@ public class CodegenImpl implements Codegen {
 	public CodegenImpl() {}
 	
 	public String codegen(Program p) throws CodegenException {
-		return "";
+		StringBuilder builder = new StringBuilder();
+		Declaration main = null;
+
+		for (Declaration d : p.decls) {
+			if (main == null) {
+				main = d;
+			}
+			
+			builder.append(compileDeclaration(d));
+		}
+		
+		return builder.toString()
+		+ "call " + String.format("%s_%d:\n", main.id, main.numOfArgs);
 	}
 
 	private String generateLabel() {
@@ -88,15 +100,16 @@ public class CodegenImpl implements Codegen {
 			String compLabel = generateLabel();
 			String bodyLabel = generateLabel();
 			String exitLabel = generateLabel();
+			String contLabel = generateLabel();
 			String breakLabel = generateLabel();
 
 			return "sw s2,-8(sp)\n"
 			+ "sw s3,-4(sp)\n"
 			+ "addi sp,sp,-8\n"
-			+ "la s2," + bodyLabel + "\n" // TODO: does this jump to the check?
+			+ "la s2," + contLabel + "\n"
 			+ "la s3," + breakLabel + "\n"
 			+ bodyLabel + ": " + compileExp(eUntil.body)
-			+ "sw s4,-4(sp)\n"
+			+ contLabel + ": sw s4,-4(sp)\n"
 			+ "addi sp,sp,-4\n"
 			+ "mv s4,a0\n"
 			+ compileFullComp(eUntil.l, eUntil.r, eUntil.comp, exitLabel, compLabel)
@@ -136,7 +149,7 @@ public class CodegenImpl implements Codegen {
 		StringBuilder builder = new StringBuilder();
 
 		// Store return address & current stack pointer
-		builder.append("mv s3,sp\n");
+		builder.append("mv s7,sp\n");
 		builder.append("sw ra,-4(sp)\n");
 		builder.append("addi sp,sp,-4\n");
 
@@ -152,7 +165,7 @@ public class CodegenImpl implements Codegen {
 
 		// push old frame pointer & start-of-frame pointer
 		builder.append("sw fp,-4(sp)\n");
-		builder.append("sw s3,-8(sp)\n");
+		builder.append("sw s7,-8(sp)\n");
 		builder.append("addi sp,sp,-8\n");
 
 		builder.append(