CFG Graph Visualizer (#11)

* add graph support

* add a requirements.txt for plot.py

.gitignore

@@ -1,9 +1,11 @@
 .zig-cache/
-zig-out/
-temp/
 .vscode/
-traces/
+zig-out/
 
-# Don't want any artifacts
+graph/*
+!graph/plot.py
+!graph/requirements.txt
+
+traces/
 **/__pycache__
-demo/
+demo/

graph/plot.py

@@ -0,0 +1,107 @@
+import struct
+import matplotlib.pyplot as plt
+import networkx as nx
+import math
+
+def get_offset_pos(pos, edges, offset_scale=0.03):
+    offset_pos = {node: pos[node] for node in pos}
+    for edge in edges:
+        x1, y1 = pos[edge[0]]
+        x2, y2 = pos[edge[1]]
+        dx = x2 - x1
+        dy = y2 - y1
+        length = math.sqrt(dx*dx + dy*dy)
+        if length == 0:
+            continue
+        offset_x = offset_scale * dy / length
+        offset_y = -offset_scale * dx / length
+        offset_pos[edge[0]] = (offset_pos[edge[0]][0] + offset_x, offset_pos[edge[0]][1] + offset_y)
+        offset_pos[edge[1]] = (offset_pos[edge[1]][0] + offset_x, offset_pos[edge[1]][1] + offset_y)
+    return offset_pos
+
+def read_graph_binary(filename):
+    nodes = []
+    edges = []
+    cfg_edges = []
+
+    with open(filename, "rb") as file:
+        while True:
+            node_id_bytes = file.read(4)
+            if not node_id_bytes:
+                break
+            node_id = struct.unpack("i", node_id_bytes)[0]
+            if node_id == -1:
+                break
+            data_len = struct.unpack("Q", file.read(8))[0]
+            data = file.read(data_len).decode("utf-8")
+            nodes.append((node_id, data))
+
+        while True:
+            edge_from_bytes = file.read(4)
+            if not edge_from_bytes:
+                break
+            edge_from = struct.unpack("i", edge_from_bytes)[0]
+            if edge_from == -1:
+                break
+            edge_to = struct.unpack("i", file.read(4))[0]
+            edges.append((edge_from, edge_to))
+
+        while True:
+            cfg_from_bytes = file.read(4)
+            if not cfg_from_bytes:
+                break
+            cfg_from = struct.unpack("i", cfg_from_bytes)[0]
+            cfg_to = struct.unpack("i", file.read(4))[0]
+            cfg_edges.append((cfg_from, cfg_to))
+
+    return nodes, edges, cfg_edges
+
+nodes, edges, cfg_edges = read_graph_binary("graph.bin")
+
+G = nx.DiGraph()
+
+for node in nodes:
+    G.add_node(node[0], label=node[1])
+
+for edge in edges:
+    G.add_edge(edge[0], edge[1])
+
+predecessors = {cfg_edge[1] for cfg_edge in cfg_edges}
+nodes_with_edges = [node for node in G.nodes if G.out_degree(node) > 0 or G.in_degree(node) > 0 and node in predecessors]
+
+G_filtered = G.subgraph(nodes_with_edges).copy()
+
+# Coloring the first and last nodes in the CFG
+first_node = cfg_edges[0][0]
+predecessors = {cfg_edge[1] for cfg_edge in cfg_edges}
+nodes_with_no_successors = {node for node in G_filtered.nodes if all(cfg_edge[0] != node for cfg_edge in cfg_edges) and node in predecessors}
+
+node_colors = ['green' if node == first_node else 'red' if node in nodes_with_no_successors else 'skyblue' for node in G_filtered.nodes]
+
+pos = nx.nx_agraph.graphviz_layout(G_filtered, prog='dot')
+plt.figure(figsize=(15, 10))
+nx.draw(G_filtered, pos, with_labels=True, labels=nx.get_node_attributes(G_filtered, 'label'), node_color=node_colors, node_size=3000, font_size=10, font_color='black', font_weight='bold', edge_color='gray')
+
+data_edges_pos = pos
+cfg_edges_pos = get_offset_pos(pos, cfg_edges)
+
+for edge in edges:
+    if edge[0] in G_filtered and edge[1] in G_filtered:
+        nx.draw_networkx_edges(G_filtered, data_edges_pos, edgelist=[edge], edge_color='gray', arrows=True)
+
+scale = 4
+
+for cfg_edge in cfg_edges:
+    if cfg_edge[0] in G_filtered and cfg_edge[1] in G_filtered:
+        x1, y1 = pos[cfg_edge[0]]
+        x2, y2 = cfg_edges_pos[cfg_edge[1]]
+        dx = x2 - x1
+        dy = y2 - y1
+        length = math.sqrt(dx*dx + dy*dy)
+        if length == 0:
+            continue
+        offset_x = scale * dy / length
+        offset_y = -scale * dx / length
+        plt.arrow(x1 + offset_x, y1 + offset_y, dx, dy, color='red', linewidth=1, head_width=0.1, head_length=0.2)
+
+plt.savefig("out.png")

graph/requirements.txt

@@ -0,0 +1,2 @@
+matplotlib >= 3.8.4
+networkx >= 2.8.8

src/compiler/Instruction.zig

@@ -71,6 +71,15 @@ fn format2(
     }
 }
 
+pub fn returns(
+    inst: Instruction,
+) bool {
+    return switch (inst.op) {
+        .RETURN_VALUE => true,
+        else => false,
+    };
+}
+
 pub fn fmt(inst: Instruction, co: CodeObject) std.fmt.Formatter(format2) {
     return .{ .data = .{
         .co = co,