feat(ir): Add Callgraph (#185)

Closes #91

---------

Co-authored-by: Georgiy Komarov <[email protected]>

CHANGELOG.md

@@ -8,6 +8,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 
 ### Added
+- Add Callgraph: PR [#185](https://github.com/nowarp/misti/pull/185)
 - `EtaLikeSimplifications` detector: PR [#198](https://github.com/nowarp/misti/pull/198)
 - `ShortCircuitCondition` detector: PR [#202](https://github.com/nowarp/misti/pull/202)
 ### Changed 

cspell.json

@@ -101,7 +101,8 @@
     "Dont",
     "consteval",
     "Georgiy",
-    "Komarov"
+    "Komarov",
+    "callgraph"
   ],
   "flagWords": [],
   "ignorePaths": [

src/internals/ir/builders/ir.ts

@@ -13,12 +13,14 @@ import {
   FunctionName,
   ImportGraph,
   ProjectName,
+  TactASTStore,
 } from "..";
-import { TactASTStoreBuilder } from "./astStore";
 import { MistiContext } from "../../context";
 import { InternalException } from "../../exceptions";
 import { formatPosition } from "../../tact";
 import { unreachable } from "../../util";
+import { CallGraph } from "../callGraph";
+import { TactASTStoreBuilder } from "./astStore";
 import {
   AstContractDeclaration,
   AstExpression,
@@ -53,6 +55,17 @@ function generateReceiveName(receive: AstReceiver): string {
   }
 }
 
+export class TactCallGraphBuilder {
+  /**
+   * Builds a CallGraph for the provided AST Store.
+   * @param astStore The TactASTStore containing AST nodes and function definitions.
+   * @returns A CallGraph instance built from the AST nodes.
+   */
+  static make(ctx: MistiContext, astStore: TactASTStore): CallGraph {
+    const callGraph = new CallGraph(ctx);
+    return callGraph.build(astStore);
+  }
+}
 /**
  * Represents a stateful object which is responsible for constructing the IR of a Tact project.
  *
@@ -98,12 +111,15 @@ export class TactIRBuilder {
   build(): CompilationUnit {
     const functions = this.createFunctions();
     const contracts = this.createContracts();
+    const tactASTStore = TactASTStoreBuilder.make(this.ctx, this.ast).build();
+    const callGraph = TactCallGraphBuilder.make(this.ctx, tactASTStore);
     return new CompilationUnit(
       this.projectName,
       TactASTStoreBuilder.make(this.ctx, this.ast).build(),
       this.imports,
       functions,
       contracts,
+      callGraph,
     );
   }
 

src/internals/ir/callGraph.ts

@@ -0,0 +1,249 @@
+import { unreachable } from "../util";
+import { TactASTStore } from "./astStore";
+import { IdxGenerator } from "./indices";
+import { MistiContext } from "../../";
+import { Logger } from "../../internals/logger";
+import { forEachExpression } from "../tact/iterators";
+import {
+  AstFunctionDef,
+  AstReceiver,
+  AstContractInit,
+  AstExpression,
+  AstMethodCall,
+  AstStaticCall,
+} from "@tact-lang/compiler/dist/grammar/ast";
+
+type CGNodeId = number & { readonly brand: unique symbol };
+type CGEdgeId = number & { readonly brand: unique symbol };
+
+/**
+ * Represents an edge in the call graph, indicating a call from one function to another.
+ */
+class CGEdge {
+  public idx: CGEdgeId;
+
+  constructor(
+    public src: CGNodeId,
+    public dst: CGNodeId,
+  ) {
+    this.idx = IdxGenerator.next("cg_edge") as CGEdgeId;
+  }
+}
+
+/**
+ * Represents a node in the call graph, corresponding to a function or method.
+ */
+class CGNode {
+  public idx: CGNodeId;
+  public inEdges: Set<CGEdgeId> = new Set();
+  public outEdges: Set<CGEdgeId> = new Set();
+
+  /**
+   * @param astId AST id of the relevant function definition. It might be `undefined` if this node doesn’t have a corresponding AST entry,
+   * which indicates an issue in Misti.
+   */
+  constructor(
+    public astId: number | undefined,
+    public name: string,
+    private logger: Logger,
+  ) {
+    this.idx = IdxGenerator.next("cg_node") as CGNodeId;
+    if (astId === undefined) {
+      this.logger.debug(`CGNode created without AST ID for function "${name}"`);
+    }
+  }
+}
+
+/**
+ * The `CallGraph` class represents a directed graph where nodes correspond to functions
+ * or methods in a program, and edges indicate calls between them.
+ *
+ * Nodes and edges are uniquely identified using indices generated by `IdxGenerator`.
+ * This class provides methods to construct the graph from AST data, retrieve nodes and edges,
+ * and check connectivity between nodes.
+ */
+export class CallGraph {
+  private nodeMap: Map<CGNodeId, CGNode> = new Map();
+  private edgesMap: Map<CGEdgeId, CGEdge> = new Map();
+  private nameToNodeId: Map<string, CGNodeId> = new Map();
+  private logger: Logger;
+
+  constructor(private ctx: MistiContext) {
+    this.logger = ctx.logger;
+  }
+
+  public getNodes(): Map<CGNodeId, CGNode> {
+    return this.nodeMap;
+  }
+
+  public getEdges(): Map<CGEdgeId, CGEdge> {
+    return this.edgesMap;
+  }
+
+  /**
+   * Builds the call graph based on functions in the provided AST store.
+   * @param astStore - The AST store containing functions to be added to the graph.
+   * @returns The constructed `CallGraph`.
+   */
+  public build(astStore: TactASTStore): CallGraph {
+    for (const func of astStore.getFunctions()) {
+      const funcName = this.getFunctionName(func);
+      if (funcName) {
+        const node = new CGNode(func.id, funcName, this.logger);
+        this.nodeMap.set(node.idx, node);
+        this.nameToNodeId.set(funcName, node.idx);
+      } else {
+        this.logger.error(
+          `Function with id ${func.id} has no name and will be skipped.`,
+        );
+      }
+    }
+    this.analyzeFunctionCalls(astStore);
+    return this;
+  }
+
+  /**
+   * Determines if there exists a path in the call graph from the source node to the destination node.
+   * This method performs a breadth-first search to find if the destination node is reachable from the source node.
+   *
+   * @param src The ID of the source node to start the search from
+   * @param dst The ID of the destination node to search for
+   * @returns true if there exists a path from src to dst in the call graph, false otherwise
+   *          Returns false if either src or dst node IDs are not found in the graph
+   */
+  public areConnected(src: CGNodeId, dst: CGNodeId): boolean {
+    const srcNode = this.nodeMap.get(src);
+    const dstNode = this.nodeMap.get(dst);
+    if (!srcNode || !dstNode) {
+      return false;
+    }
+    const queue: CGNodeId[] = [src];
+    const visited = new Set<CGNodeId>([src]);
+    while (queue.length > 0) {
+      const current = queue.shift()!;
+      if (current === dst) {
+        return true;
+      }
+      const currentNode = this.nodeMap.get(current);
+      if (currentNode) {
+        for (const edgeId of currentNode.outEdges) {
+          const edge = this.edgesMap.get(edgeId);
+          if (edge && !visited.has(edge.dst)) {
+            visited.add(edge.dst);
+            queue.push(edge.dst);
+          }
+        }
+      }
+    }
+    return false;
+  }
+
+  /**
+   * Analyzes function calls in the AST store and adds corresponding edges in the call graph.
+   * @param astStore The AST store to analyze for function calls.
+   */
+  private analyzeFunctionCalls(astStore: TactASTStore) {
+    for (const func of astStore.getFunctions()) {
+      const funcName = this.getFunctionName(func);
+      if (funcName) {
+        const callerId = this.nameToNodeId.get(funcName);
+        if (callerId !== undefined) {
+          forEachExpression(func, (expr) =>
+            this.processExpression(expr, callerId),
+          );
+        } else {
+          this.logger.warn(
+            `Caller function ${funcName} not found in node map.`,
+          );
+        }
+      }
+    }
+  }
+
+  /**
+   * Extracts the function name based on its type.
+   * @param func The function definition, receiver, or contract initializer.
+   * @returns The function name if available; otherwise, `undefined`.
+   */
+  private getFunctionName(
+    func: AstFunctionDef | AstReceiver | AstContractInit,
+  ): string | undefined {
+    switch (func.kind) {
+      case "function_def":
+        return func.name?.text;
+      case "contract_init":
+        return `contract_init_${func.id}`;
+      case "receiver":
+        return `receiver_${func.id}`;
+      default:
+        unreachable(func);
+    }
+  }
+
+  /**
+   * Processes an expression, identifying static and method calls to add edges.
+   * @param expr The AST expression to process.
+   * @param callerId The ID of the calling node.
+   */
+  private processExpression(expr: AstExpression, callerId: CGNodeId) {
+    if (expr.kind === "static_call") {
+      const staticCall = expr as AstStaticCall;
+      const functionName = staticCall.function?.text;
+      if (functionName) {
+        const calleeId = this.findOrAddFunction(functionName);
+        this.addEdge(callerId, calleeId);
+      } else {
+        this.logger.warn(
+          `Static call expression missing function name at caller ${callerId}`,
+        );
+      }
+    } else if (expr.kind === "method_call") {
+      const methodCall = expr as AstMethodCall;
+      const methodName = methodCall.method?.text;
+      if (methodName) {
+        const calleeId = this.findOrAddFunction(methodName);
+        this.addEdge(callerId, calleeId);
+      } else {
+        this.logger.warn(
+          `Method call expression missing method name at caller ${callerId}`,
+        );
+      }
+    }
+  }
+
+  /**
+   * Finds or adds a function to the call graph by name.
+   * @param name The name of the function to find or add.
+   * @returns The ID of the found or added function node.
+   */
+  private findOrAddFunction(name: string): CGNodeId {
+    const nodeId = this.nameToNodeId.get(name);
+    if (nodeId !== undefined) {
+      return nodeId;
+    }
+    const newNode = new CGNode(undefined, name, this.logger);
+    this.nodeMap.set(newNode.idx, newNode);
+    this.nameToNodeId.set(name, newNode.idx);
+    return newNode.idx;
+  }
+
+  /**
+   * Adds an edge between two nodes in the call graph.
+   * @param src The source node ID.
+   * @param dst The destination node ID.
+   */
+  private addEdge(src: CGNodeId, dst: CGNodeId) {
+    const srcNode = this.nodeMap.get(src);
+    const dstNode = this.nodeMap.get(dst);
+    if (srcNode && dstNode) {
+      const edge = new CGEdge(src, dst);
+      this.edgesMap.set(edge.idx, edge);
+      srcNode.outEdges.add(edge.idx);
+      dstNode.inEdges.add(edge.idx);
+    } else {
+      this.logger.warn(
+        `Cannot add edge from ${src} to ${dst}: node(s) not found.`,
+      );
+    }
+  }
+}

src/internals/ir/ir.ts

@@ -5,6 +5,7 @@
  */
 import { CFGIdx, ContractName, FunctionName, ProjectName } from ".";
 import { TactASTStore } from "./astStore";
+import { CallGraph } from "./callGraph";
 import { BasicBlock, CFG } from "./cfg";
 import { ImportGraph } from "./imports";
 import { IdxGenerator } from "./indices";
@@ -31,6 +32,7 @@ export class CompilationUnit {
     public imports: ImportGraph,
     public functions: Map<CFGIdx, CFG>,
     public contracts: Map<ContractIdx, Contract>,
+    public callGraph: CallGraph,
   ) {}
 
   /**