fix(ast): 规范AST输出

src/ast/AstNodes.h

@@ -1,6 +1,7 @@
 
 #pragma once
 
+#include <iosfwd>
 #include <memory>
 #include <string>
 #include <vector>
@@ -66,5 +67,7 @@ struct CompUnit {
 
 // 调试打印
 void PrintAST(const CompUnit& cu);
+// 导出 AST 为 Graphviz DOT。
+void PrintASTDot(const CompUnit& cu, std::ostream& os);
 
 }  // namespace ast

src/ast/AstPrinter.cpp

@@ -3,70 +3,194 @@
 #include "ast/AstNodes.h"
 
 #include <iostream>
+#include <ostream>
+#include <string>
 
 namespace ast {
 
-static void PrintExpr(const Expr* expr);
-
 static void PrintIndent(int depth) {
   for (int i = 0; i < depth; ++i) std::cout << "  ";
 }
 
-static void PrintExpr(const Expr* expr) {
+static void PrintLine(int depth, const std::string& text) {
+  PrintIndent(depth);
+  std::cout << text << "\n";
+}
+
+static void DumpExpr(const Expr* expr, int depth) {
+  if (!expr) {
+    PrintLine(depth, "NullExpr");
+    return;
+  }
+
   if (auto num = dynamic_cast<const NumberExpr*>(expr)) {
-    std::cout << num->value;
-  } else if (auto var = dynamic_cast<const VarExpr*>(expr)) {
-    std::cout << var->name;
-  } else if (auto bin = dynamic_cast<const BinaryExpr*>(expr)) {
-    std::cout << "(";
-    PrintExpr(bin->lhs.get());
+    PrintLine(depth, "NumberExpr value=" + std::to_string(num->value));
+    return;
+  }
+  if (auto var = dynamic_cast<const VarExpr*>(expr)) {
+    PrintLine(depth, "VarExpr name=" + var->name);
+    return;
+  }
+  if (auto bin = dynamic_cast<const BinaryExpr*>(expr)) {
     const char* op = "?";
     switch (bin->op) {
       case BinaryOp::Add:
-        op = "+";
+        op = "Add";
         break;
       case BinaryOp::Sub:
-        op = "-";
+        op = "Sub";
         break;
       case BinaryOp::Mul:
-        op = "*";
+        op = "Mul";
         break;
       case BinaryOp::Div:
-        op = "/";
+        op = "Div";
         break;
     }
-    std::cout << " " << op << " ";
-    PrintExpr(bin->rhs.get());
-    std::cout << ")";
+    PrintLine(depth, std::string("BinaryExpr op=") + op);
+    DumpExpr(bin->lhs.get(), depth + 1);
+    DumpExpr(bin->rhs.get(), depth + 1);
+    return;
   }
+
+  PrintLine(depth, "UnknownExpr");
 }
 
 void PrintAST(const CompUnit& cu) {
-  if (!cu.func) return;
-  std::cout << "func " << cu.func->name << " () {\n";
+  PrintLine(0, "CompUnit");
+  if (!cu.func) {
+    PrintLine(1, "<empty>");
+    return;
+  }
+
+  PrintLine(1, "FuncDef name=" + cu.func->name);
   const auto& body = cu.func->body;
   if (!body) {
-    std::cout << "}\n";
+    PrintLine(2, "Block <null>");
     return;
   }
+
+  PrintLine(2, "Block");
   for (const auto& decl : body->varDecls) {
-    PrintIndent(1);
-    std::cout << "var " << decl->name;
+    PrintLine(3, "VarDecl name=" + decl->name);
     if (decl->init) {
-      std::cout << " = ";
-      PrintExpr(decl->init.get());
+      PrintLine(4, "Init");
+      DumpExpr(decl->init.get(), 5);
     }
-    std::cout << ";\n";
   }
   for (const auto& stmt : body->stmts) {
     if (auto ret = dynamic_cast<ReturnStmt*>(stmt.get())) {
-      PrintIndent(1);
-      std::cout << "return ";
-      PrintExpr(ret->value.get());
-      std::cout << ";\n";
+      PrintLine(3, "ReturnStmt");
+      DumpExpr(ret->value.get(), 4);
+    } else {
+      PrintLine(3, "UnknownStmt");
+    }
+  }
+}
+
+namespace {
+
+std::string EscapeDotLabel(const std::string& s) {
+  std::string out;
+  out.reserve(s.size());
+  for (char c : s) {
+    if (c == '\\' || c == '"') out.push_back('\\');
+    out.push_back(c);
+  }
+  return out;
+}
+
+class DotWriter {
+ public:
+  explicit DotWriter(std::ostream& os) : os_(os) {}
+
+  int AddNode(const std::string& label) {
+    int id = next_id_++;
+    os_ << "  n" << id << " [label=\"" << EscapeDotLabel(label) << "\"];\n";
+    return id;
+  }
+
+  void AddEdge(int from, int to) { os_ << "  n" << from << " -> n" << to << ";\n"; }
+
+ private:
+  std::ostream& os_;
+  int next_id_ = 0;
+};
+
+int EmitExpr(const Expr* expr, DotWriter& dot) {
+  if (!expr) return dot.AddNode("NullExpr");
+
+  if (auto num = dynamic_cast<const NumberExpr*>(expr)) {
+    return dot.AddNode("Number(" + std::to_string(num->value) + ")");
+  }
+  if (auto var = dynamic_cast<const VarExpr*>(expr)) {
+    return dot.AddNode("Var(" + var->name + ")");
+  }
+  if (auto bin = dynamic_cast<const BinaryExpr*>(expr)) {
+    const char* op = "?";
+    switch (bin->op) {
+      case BinaryOp::Add:
+        op = "Add";
+        break;
+      case BinaryOp::Sub:
+        op = "Sub";
+        break;
+      case BinaryOp::Mul:
+        op = "Mul";
+        break;
+      case BinaryOp::Div:
+        op = "Div";
+        break;
+    }
+    int id = dot.AddNode(std::string("Binary(") + op + ")");
+    int lhs = EmitExpr(bin->lhs.get(), dot);
+    int rhs = EmitExpr(bin->rhs.get(), dot);
+    dot.AddEdge(id, lhs);
+    dot.AddEdge(id, rhs);
+    return id;
+  }
+  return dot.AddNode("UnknownExpr");
+}
+
+}  // namespace
+
+void PrintASTDot(const CompUnit& cu, std::ostream& os) {
+  os << "digraph AST {\n";
+  os << "  rankdir=TB;\n";
+  os << "  node [shape=box, fontname=\"Courier\"];\n";
+
+  DotWriter dot(os);
+  int cu_id = dot.AddNode("CompUnit");
+  if (cu.func) {
+    int func_id = dot.AddNode("FuncDef(" + cu.func->name + ")");
+    dot.AddEdge(cu_id, func_id);
+    if (cu.func->body) {
+      int block_id = dot.AddNode("Block");
+      dot.AddEdge(func_id, block_id);
+
+      for (const auto& decl : cu.func->body->varDecls) {
+        int decl_id = dot.AddNode("VarDecl(" + decl->name + ")");
+        dot.AddEdge(block_id, decl_id);
+        if (decl->init) {
+          int init_id = EmitExpr(decl->init.get(), dot);
+          dot.AddEdge(decl_id, init_id);
+        }
+      }
+
+      for (const auto& stmt : cu.func->body->stmts) {
+        if (auto ret = dynamic_cast<ReturnStmt*>(stmt.get())) {
+          int ret_id = dot.AddNode("Return");
+          dot.AddEdge(block_id, ret_id);
+          int value_id = EmitExpr(ret->value.get(), dot);
+          dot.AddEdge(ret_id, value_id);
+        } else {
+          int stmt_id = dot.AddNode("Stmt");
+          dot.AddEdge(block_id, stmt_id);
+        }
+      }
     }
   }
-  std::cout << "}\n";
+  os << "}\n";
 }
 
 }  // namespace ast

src/main.cpp

@@ -1,5 +1,7 @@
 #include <exception>
+#include <fstream>
 #include <iostream>
+#include <stdexcept>
 
 #include "frontend/AntlrDriver.h"
 #include "frontend/AstBuilder.h"
@@ -20,8 +22,15 @@ int main(int argc, char** argv) {
     auto antlr = ParseFileWithAntlr(opts.input);
     auto ast = BuildAst(antlr.tree);
     ast::PrintAST(*ast);  // 调试 AST
+    if (!opts.ast_dot_output.empty()) {
+      std::ofstream dot_out(opts.ast_dot_output);
+      if (!dot_out) {
+        throw std::runtime_error("无法写入 AST DOT 文件: " + opts.ast_dot_output);
+      }
+      ast::PrintASTDot(*ast, dot_out);
+    }
     ast = RunSema(std::move(ast));
-    // IR 生成：当前使用 IRGenDriver.cpp 里的最小参考实现，
+    // IR 生成：当前使用 IRGenDriver.cpp 里的最小实现，
     // 同学们可以在 irgen/ 目录下按提示自行完善或替换实现。
     auto module = GenerateIR(*ast);
 

src/utils/CLI.cpp

@@ -5,15 +5,15 @@
 
 #include "utils/CLI.h"
 
-#include <cstring>
-#include <string>
 #include <stdexcept>
+#include <string>
+#include <cstring>
 
 CLIOptions ParseCLI(int argc, char** argv) {
   CLIOptions opt;
 
   if (argc <= 1) {
-    throw std::runtime_error("用法: compiler [--help] <input.sy>");
+    throw std::runtime_error("用法: compiler [--help] [--ast-dot <file.dot>] <input.sy>");
   }
 
   for (int i = 1; i < argc; ++i) {
@@ -23,6 +23,14 @@ CLIOptions ParseCLI(int argc, char** argv) {
       return opt;
     }
 
+    if (std::strcmp(arg, "--ast-dot") == 0) {
+      if (i + 1 >= argc) {
+        throw std::runtime_error("参数错误: --ast-dot 需要一个输出路径");
+      }
+      opt.ast_dot_output = argv[++i];
+      continue;
+    }
+
     if (arg[0] == '-') {
       throw std::runtime_error(std::string("未知参数: ") + arg +
                                "（使用 --help 查看用法）");
@@ -35,7 +43,7 @@ CLIOptions ParseCLI(int argc, char** argv) {
     opt.input = arg;
   }
 
-  if (opt.input.empty()) {
+  if (opt.input.empty() && !opt.show_help) {
     throw std::runtime_error("缺少输入文件：请提供 <input.sy>（使用 --help 查看用法）");
   }
   return opt;

src/utils/CLI.h

@@ -1,10 +1,11 @@
-// 简易命令行解析：仅支持输入文件路径。
+// 简易命令行解析：支持帮助、输入文件和 AST DOT 导出。
 #pragma once
 
 #include <string>
 
 struct CLIOptions {
   std::string input;
+  std::string ast_dot_output;
   bool show_help = false;
 };
 

src/utils/Log.cpp

@@ -10,10 +10,11 @@ void PrintHelp(std::ostream& os) {
   os << "SysY Compiler (课程实验最小可运行示例)\n"
      << "\n"
      << "用法:\n"
-     << "  compiler [--help] <input.sy>\n"
+     << "  compiler [--help] [--ast-dot <file.dot>] <input.sy>\n"
      << "\n"
      << "选项:\n"
      << "  -h, --help        打印帮助信息并退出\n"
+     << "  --ast-dot <path>  导出 AST Graphviz DOT 到指定文件\n"
      << "\n"
      << "说明:\n"
      << "  - 当前默认将 IR 输出到标准输出，可使用重定向写入文件:\n"