First flowgraph?

src/main/java/codegen/analysis/flowgraph/FlowGraph.java

@@ -0,0 +1,39 @@
+package codegen.analysis.flowgraph;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class FlowGraph {
+
+    private final FlowGraphHead head;
+    private final List<FlowGraphBlock> blocks;
+    private final FlowGraphTail tail;
+
+    public FlowGraph(FlowGraphHead head, List<FlowGraphBlock> blocks, FlowGraphTail tail) {
+        this.head = head;
+        this.blocks = blocks;
+        this.tail = tail;
+    }
+
+    public void print() {
+        final String blocksString = this.blocks.stream()
+                                               .map(FlowGraphBlock::toString)
+                                               .map(string -> string + "-".repeat(50))
+                                               .collect(Collectors.joining());
+
+        System.out.println(this.head + "-".repeat(100)
+                           + blocksString + "-".repeat(100)
+                           + this.tail);
+    }
+
+    @Override
+    public String toString() {
+        final String blocksString = this.blocks.stream()
+                                               .map(FlowGraphBlock::toString)
+                                               .collect(Collectors.joining());
+
+        return this.head
+               + blocksString
+               + this.tail;
+    }
+}

src/main/java/codegen/analysis/flowgraph/FlowGraphBlock.java

@@ -0,0 +1,25 @@
+package codegen.analysis.flowgraph;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class FlowGraphBlock {
+
+    private final String label;
+    private final List<FlowGraphLine> lines;
+
+    public FlowGraphBlock(String label, List<FlowGraphLine> lines) {
+        this.label = label;
+        this.lines = lines;
+    }
+
+    @Override
+    public String toString() {
+        final String linesString = this.lines.stream()
+                                             .map(FlowGraphLine::toString)
+                                             .collect(Collectors.joining());
+
+        return this.label + ":\n"
+               + linesString;
+    }
+}

src/main/java/codegen/analysis/flowgraph/FlowGraphHead.java

@@ -0,0 +1,37 @@
+package codegen.analysis.flowgraph;
+
+public class FlowGraphHead {
+
+    private final String bytecodeVersion;
+    private final String source;
+    private final String clazz;
+    private final int stackSize;
+    private final int localCount;
+
+    public FlowGraphHead(String bytecodeVersion, String source, String clazz, int stackSize, int localCount) {
+        this.bytecodeVersion = bytecodeVersion;
+        this.source = source;
+        this.clazz = clazz;
+        this.stackSize = stackSize;
+        this.localCount = localCount;
+    }
+
+    @Override
+    public String toString() {
+        return ".bytecode " + this.bytecodeVersion + "\n"
+               + ".source " + this.source + "\n"
+               + ".class public" + this.clazz + "\n"
+               + ".super java/lang/Object\n"
+               + ".method public <init>()V\n"
+               + "\t.limit stack 1\n"
+               + "\t.limit locals 1\n"
+               + "\t\taload_0\n"
+               + "\t\tinvokespecial java/lang/Object/<init>()V\n"
+               + "\t\treturn\n"
+               + ".end method\n\n"
+
+               + ".method public static main([Ljava/lang/String;)V\n"
+               + "\t.limit stack " + this.stackSize + "\n"
+               + "\t.limit locals " + this.localCount + "\n";
+    }
+}

src/main/java/codegen/analysis/flowgraph/FlowGraphLine.java

@@ -0,0 +1,19 @@
+package codegen.analysis.flowgraph;
+
+public class FlowGraphLine {
+
+    private final String instruction;
+    private final String[] args;
+
+    public FlowGraphLine(String instruction, String... args) {
+        this.instruction = instruction;
+        this.args = args;
+    }
+
+    @Override
+    public String toString() {
+        final String argsString = String.join(" ", this.args);
+
+        return "\t\t" + this.instruction + " " + argsString;
+    }
+}

src/main/java/codegen/analysis/flowgraph/FlowGraphTail.java

@@ -0,0 +1,10 @@
+package codegen.analysis.flowgraph;
+
+public class FlowGraphTail {
+
+    @Override
+    public String toString() {
+        return "\t\treturn\n"
+               + ".end method";
+    }
+}