From 34d0e1bb0ed84ca4733811f837ea5847be3cd924 Mon Sep 17 00:00:00 2001
From: Marvin Kaiser <marvin.kaiser.93@gmail.com>
Date: Tue, 14 Jan 2020 18:37:34 +0100
Subject: [PATCH] Added cli argument to either generate main method or not

---
 src/main/java/de/hsrm/compiler/Klang/Klang.java     |  7 ++++++-
 .../de/hsrm/compiler/Klang/visitors/GenASM.java     | 13 ++++++++++---
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/src/main/java/de/hsrm/compiler/Klang/Klang.java b/src/main/java/de/hsrm/compiler/Klang/Klang.java
index 19f3268..5696616 100644
--- a/src/main/java/de/hsrm/compiler/Klang/Klang.java
+++ b/src/main/java/de/hsrm/compiler/Klang/Klang.java
@@ -17,6 +17,7 @@ public class Klang {
     boolean evaluate = false;
     boolean prettyPrint = false;
     boolean compile = true;
+    String mainName = "main";
 
     List<String> arguments = Arrays.asList(args);
     if (arguments.contains("-h") || arguments.contains("--help") || arguments.contains("?")) {
@@ -29,6 +30,7 @@ public class Klang {
       System.out.println("--evaluate:\t Evaluates the given source code");
       System.out.println("--pretty:\t Pretty print the given source code");
       System.out.println("--no-compile:\t Do not compile the source code");
+      System.out.println("--no-main:\t Do not generate main function, will be generated as 'start'. Useful for testing");
       return;
     }
     if (arguments.contains("--evaluate")) {
@@ -40,6 +42,9 @@ public class Klang {
     if (arguments.contains("--no-compile")) {
       compile = false;
     }
+    if (arguments.contains("--no-main")) {
+      mainName = "start";
+    }
 
     // create a CharStream that reads from standard input
     CharStream input = CharStreams.fromStream(System.in);
@@ -71,7 +76,7 @@ public class Klang {
       // System.out.println("\nPrinting the assembler code");
       StringWriter wAsm = new StringWriter();
       GenASM.ExWriter exAsm = new GenASM.ExWriter(wAsm);
-      GenASM genasm = new GenASM(exAsm);
+      GenASM genasm = new GenASM(exAsm, mainName);
       node.welcome(genasm);
       System.out.println(wAsm.toString());
     }
diff --git a/src/main/java/de/hsrm/compiler/Klang/visitors/GenASM.java b/src/main/java/de/hsrm/compiler/Klang/visitors/GenASM.java
index eeb48aa..d021f1d 100644
--- a/src/main/java/de/hsrm/compiler/Klang/visitors/GenASM.java
+++ b/src/main/java/de/hsrm/compiler/Klang/visitors/GenASM.java
@@ -56,13 +56,20 @@ public class GenASM implements Visitor<Void> {
   }
 
   public ExWriter ex;
+  private String mainName;
   Map<String, Integer> env = new HashMap<>();
   Set<String> vars;
   String[] rs = { "%rdi", "%rsi", "%rdx", "%rcx", "%r8", "%r9" };
   private int lCount = 0; // Invariante: lCount ist benutzt
 
+  public GenASM(ExWriter ex, String mainName) {
+    this.ex = ex;
+    this.mainName = mainName;
+  }
+
   public GenASM(ExWriter ex) {
     this.ex = ex;
+    this.mainName = "main";
   }
 
   @Override
@@ -445,9 +452,9 @@ public class GenASM implements Visitor<Void> {
       func.welcome(this);
       this.ex.write("\n");
     }
-    this.ex.write(".globl start\n");
-    this.ex.write(".type start, @function\n");
-    this.ex.write("start:\n");
+    this.ex.write(".globl " + mainName + "\n");
+    this.ex.write(".type " +mainName + ", @function\n");
+    this.ex.write(mainName + ":\n");
     this.ex.write("    pushq %rbp\n");
     this.ex.write("    movq %rsp, %rbp\n");
     e.expression.welcome(this);