diff --git a/src/main/java/de/hsrm/compiler/Klang/ContextAnalysis.java b/src/main/java/de/hsrm/compiler/Klang/ContextAnalysis.java
index fe160b8..73acc9d 100644
--- a/src/main/java/de/hsrm/compiler/Klang/ContextAnalysis.java
+++ b/src/main/java/de/hsrm/compiler/Klang/ContextAnalysis.java
@@ -3,6 +3,7 @@ package de.hsrm.compiler.Klang;
 import java.util.Map;
 import java.util.HashMap;
 
+import de.hsrm.compiler.Klang.helper.FunctionInformation;
 import de.hsrm.compiler.Klang.nodes.*;
 import de.hsrm.compiler.Klang.nodes.expressions.*;
 import de.hsrm.compiler.Klang.nodes.loops.DoWhileLoop;
@@ -13,9 +14,13 @@ import de.hsrm.compiler.Klang.types.Type;
 
 public class ContextAnalysis extends KlangBaseVisitor<Node> {
   Map<String, VariableDeclaration> vars = new HashMap<>();
-  Map<String, FunctionDefinition> funcs = new HashMap<>();
+  Map<String, FunctionInformation> funcs;
   Type currentDeclaredReturnType;
 
+  public ContextAnalysis(Map<String, FunctionInformation> funcs) {
+    this.funcs = funcs;
+  }
+
   @Override
   public Node visitProgram(KlangParser.ProgramContext ctx) {
     FunctionDefinition[] funcs = new FunctionDefinition[ctx.functionDef().size()];
@@ -383,14 +388,6 @@ public class ContextAnalysis extends KlangBaseVisitor<Node> {
     FunctionDefinition result = new FunctionDefinition(name, params, (Block) block);
     result.type = returnType;
 
-    // Add this function to our environment
-    
-    // TODO
-    // Geht nicht weil das bei ner Rekursion um die ohren fliegt,
-    // der funktionsprototyp muss in die funcs geschrieben werden,
-    // bevor der block gevisited wird
-    this.funcs.put(name, result);
-
     return result;
   }
 
@@ -407,15 +404,14 @@ public class ContextAnalysis extends KlangBaseVisitor<Node> {
   public Node visitFunctionCallExpression(KlangParser.FunctionCallExpressionContext ctx) {
     String name = ctx.functionCall().IDENT().getText();
 
-    // Make sure the function that is called is defined
-    FunctionDefinition func = this.funcs.get(name);
+    FunctionInformation func = this.funcs.get(name);
     if (func == null) {
       throw new RuntimeException("Function with name \"" + name + "\" not defined.");
     }
 
     // Make sure the number of arguments matches the number of parameters
     int argCount = ctx.functionCall().arguments().expression().size();
-    int paramCount = func.parameters.length;
+    int paramCount = func.parameters.size();
     if (argCount != paramCount) {
       throw new RuntimeException("Function \"" + name + "\" expects " + paramCount + " parameters, but got " + argCount + ".");
     }
@@ -424,12 +420,12 @@ public class ContextAnalysis extends KlangBaseVisitor<Node> {
     Expression[] args = new Expression[argCount];
     for (int i = 0; i < argCount; i++) {
       Expression expression = (Expression) this.visit(ctx.functionCall().arguments().expression(i)); 
-      expression.type.combine(func.parameters[i].type); // Make sure the types are matching
+      expression.type.combine(func.signature[i]); // Make sure the types are matching
       args[i] = expression;
     }
 
     FunctionCall result = new FunctionCall(name, args);
-    result.type = func.type;
+    result.type = func.returnType;
     return result;
   }
 }
\ No newline at end of file
diff --git a/src/main/java/de/hsrm/compiler/Klang/GetFunctions.java b/src/main/java/de/hsrm/compiler/Klang/GetFunctions.java
new file mode 100644
index 0000000..8d157a5
--- /dev/null
+++ b/src/main/java/de/hsrm/compiler/Klang/GetFunctions.java
@@ -0,0 +1,51 @@
+package de.hsrm.compiler.Klang;
+
+import java.util.Map;
+import java.util.TreeMap;
+
+import de.hsrm.compiler.Klang.types.*;
+import de.hsrm.compiler.Klang.helper.*;
+
+public class GetFunctions extends KlangBaseVisitor<Void> {
+
+  private Map<String, FunctionInformation> funcs;
+
+  public GetFunctions(Map<String, FunctionInformation> funcs) {
+    this.funcs = funcs;
+  }
+
+  @Override
+  public Void visitProgram(KlangParser.ProgramContext ctx) {
+    for (int i = 0; i < ctx.functionDef().size(); i++) {
+      this.visit(ctx.functionDef(i));
+    }
+    return null;
+  }
+
+  @Override
+  public Void visitFunctionDef(KlangParser.FunctionDefContext ctx) {
+    String name = ctx.funcName.getText();
+
+    if (this.funcs.containsKey(name)) {
+      throw new Error("Function " + name + " defined multiple times");
+    }
+    
+    Type returnType = Type.getByName(ctx.returnType.type().getText());
+
+    TreeMap<String, Type> parameters = new TreeMap<String, Type>();
+
+    // Process the paremter list by visiting every paremter in it
+    int paramCount = ctx.params.parameter().size();
+    Type[] signature = new Type[paramCount];
+    for (int i = 0; i < paramCount; i++) {
+      Type paramType = Type.getByName(ctx.params.parameter(i).type_annotation().getText());
+      String paramName = ctx.params.parameter(i).IDENT().getText();
+      parameters.put(paramName, paramType);
+      signature[i] = paramType;
+    }
+
+    FunctionInformation information = new FunctionInformation(name, returnType, parameters, signature);
+    this.funcs.put(name, information);
+    return null;
+  }
+}
\ No newline at end of file
diff --git a/src/main/java/de/hsrm/compiler/Klang/Klang.java b/src/main/java/de/hsrm/compiler/Klang/Klang.java
index 5696616..44a12fc 100644
--- a/src/main/java/de/hsrm/compiler/Klang/Klang.java
+++ b/src/main/java/de/hsrm/compiler/Klang/Klang.java
@@ -7,9 +7,11 @@ import org.antlr.v4.runtime.tree.*;
 import java.io.*;
 import java.util.Arrays;
 import java.util.List;
+import java.util.HashMap;
 
 import de.hsrm.compiler.Klang.nodes.Node;
 import de.hsrm.compiler.Klang.visitors.*;
+import de.hsrm.compiler.Klang.helper.*;
 
 public class Klang {
 
@@ -58,8 +60,15 @@ public class Klang {
     // create a parser that feeds off the tokens buffer
     KlangParser parser = new KlangParser(tokens);
 
+    // Parse tokens to AST
     ParseTree tree = parser.parse(); // begin parsing at init rule
-    ContextAnalysis ctxAnal = new ContextAnalysis();
+
+    // Extract information about all functions
+    var functionDefinitions = new HashMap<String, FunctionInformation>();
+    new GetFunctions(functionDefinitions).visit(tree);
+
+    // Context Analysis and DAST generation
+    ContextAnalysis ctxAnal = new ContextAnalysis(functionDefinitions);
     Node node = ctxAnal.visit(tree); // this gets us the DAST
 
     if (prettyPrint) {
diff --git a/src/main/java/de/hsrm/compiler/Klang/helper/FunctionInformation.java b/src/main/java/de/hsrm/compiler/Klang/helper/FunctionInformation.java
new file mode 100644
index 0000000..97508f0
--- /dev/null
+++ b/src/main/java/de/hsrm/compiler/Klang/helper/FunctionInformation.java
@@ -0,0 +1,19 @@
+package de.hsrm.compiler.Klang.helper;
+
+import java.util.Map;
+
+import de.hsrm.compiler.Klang.types.Type;
+
+public class FunctionInformation {
+  public String name;
+  public Type returnType;
+  public Map<String, Type> parameters;
+  public Type[] signature;
+
+  public FunctionInformation(String name, Type returnType, Map<String,Type> parameters, Type[] signature) {
+    this.name = name;
+    this.returnType = returnType;
+    this.parameters = parameters;
+    this.signature = signature;
+  }  
+}
\ No newline at end of file