From bdabe5696c7f3317f89c4faa70a8fc55128b7d51 Mon Sep 17 00:00:00 2001
From: Mattias Ulbrich <ulbrich@kit.edu>
Date: Tue, 6 Dec 2022 15:47:29 +0100
Subject: [PATCH] Support for "label=number"

---
 .../edu/kit/kastel/formal/mimaflux/MimaAsm.g4     |  5 +++++
 .../kit/kastel/formal/mimaflux/LabelResolver.java | 15 ++++++++++++---
 .../kastel/formal/mimaflux/ProgramVisitor.java    |  9 +++++++++
 3 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/src/main/antlr/edu/kit/kastel/formal/mimaflux/MimaAsm.g4 b/src/main/antlr/edu/kit/kastel/formal/mimaflux/MimaAsm.g4
index 149688b..2ce5adf 100644
--- a/src/main/antlr/edu/kit/kastel/formal/mimaflux/MimaAsm.g4
+++ b/src/main/antlr/edu/kit/kastel/formal/mimaflux/MimaAsm.g4
@@ -24,6 +24,7 @@ file :
 
 line :
     adr_spec
+  | label_spec
   | command
   ;
 
@@ -31,6 +32,10 @@ adr_spec :
   '*' '=' NUMBER
   ;
 
+label_spec :
+  ID '=' NUMBER
+  ;
+
 command :
   (label=ID ':')? ( mnemomicWith (idArg=ID | numberArg=NUMBER)
               | mnemomicWithout)
diff --git a/src/main/java/edu/kit/kastel/formal/mimaflux/LabelResolver.java b/src/main/java/edu/kit/kastel/formal/mimaflux/LabelResolver.java
index f88fe05..48cbbdd 100644
--- a/src/main/java/edu/kit/kastel/formal/mimaflux/LabelResolver.java
+++ b/src/main/java/edu/kit/kastel/formal/mimaflux/LabelResolver.java
@@ -14,6 +14,8 @@
  */
 package edu.kit.kastel.formal.mimaflux;
 
+import edu.kit.kastel.formal.mimaflux.MimaAsmParser.CommandContext;
+
 import java.util.HashMap;
 import java.util.List;
 import java.util.ListIterator;
@@ -24,16 +26,23 @@ public class LabelResolver {
 
     public void resolve(List<Command> commands) {
         labelMap = new HashMap<String, Integer>();
-        for (Command command : commands) {
+        ListIterator<Command> it = commands.listIterator();
+        while (it.hasNext()) {
+            Command command = it.next();
             if (command.label() != null) {
                 if (labelMap.containsKey(command.label())) {
-                    throw new TokenedException(command.ctx().getStart(), "Symbol '" + command.label() + "' already defined");
+                    CommandContext ctx = command.ctx();
+                    throw new TokenedException(ctx != null ? ctx.getStart() : null, "Symbol '" + command.label() + "' already defined");
                 }
                 labelMap.put(command.label(), command.address());
             }
+            if (command.instruction() == null) {
+                // This was a label definition only.
+                it.remove();
+            }
         }
 
-        ListIterator<Command> it = commands.listIterator();
+        it = commands.listIterator();
         while (it.hasNext()) {
             Command command = it.next();
             if(command.labelArg() != null) {
diff --git a/src/main/java/edu/kit/kastel/formal/mimaflux/ProgramVisitor.java b/src/main/java/edu/kit/kastel/formal/mimaflux/ProgramVisitor.java
index a3dc7e9..0efcb46 100644
--- a/src/main/java/edu/kit/kastel/formal/mimaflux/ProgramVisitor.java
+++ b/src/main/java/edu/kit/kastel/formal/mimaflux/ProgramVisitor.java
@@ -16,6 +16,8 @@
 
 import edu.kit.kastel.formal.mimaflux.MimaAsmParser.Adr_specContext;
 import edu.kit.kastel.formal.mimaflux.MimaAsmParser.CommandContext;
+import edu.kit.kastel.formal.mimaflux.MimaAsmParser.Label_specContext;
+import org.antlr.v4.runtime.tree.TerminalNode;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -35,6 +37,13 @@ public Void visitAdr_spec(Adr_specContext ctx) {
         return null;
     }
 
+    @Override
+    public Void visitLabel_spec(Label_specContext ctx) {
+        Integer number = Integer.decode(ctx.NUMBER().getText());
+        commands.add(new Command(number, ctx.ID().getText(), null, null, 0, null));
+        return null;
+    }
+
     @Override
     public Void visitCommand(CommandContext ctx) {
         String label = null;