[Lldb-commits] [lldb] [LLDB] Add Lexer (with tests) for DIL (Data Inspection Language). (PR #123521)

[Andy Hippo via lldb-commits]

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+//===-- DILLexer.h ----------------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLDB_VALUEOBJECT_DILLEXER_H_
+#define LLDB_VALUEOBJECT_DILLEXER_H_
+
+#include "llvm/ADT/StringRef.h"
+#include <cstdint>
+#include <limits.h>
+#include <memory>
+#include <string>
+#include <vector>
+
+namespace lldb_private {
+
+namespace dil {
+
+enum class TokenKind {
+  coloncolon,
+  eof,
+  identifier,
+  invalid,
+  kw_namespace,
+  l_paren,
+  none,
+  r_paren,
+  unknown,
+};
+
+/// Class defining the tokens generated by the DIL lexer and used by the
+/// DIL parser.
+class DILToken {
+public:
+  DILToken(dil::TokenKind kind, std::string spelling, uint32_t start)
+      : m_kind(kind), m_spelling(spelling), m_start_pos(start) {}
+
+  DILToken() : m_kind(dil::TokenKind::none), m_spelling(""), m_start_pos(0) {}
+
+  void setKind(dil::TokenKind kind) { m_kind = kind; }
+  dil::TokenKind getKind() const { return m_kind; }
+
+  std::string getSpelling() const { return m_spelling; }
+
+  uint32_t getLength() const { return m_spelling.size(); }
+
+  bool is(dil::TokenKind kind) const { return m_kind == kind; }
+
+  bool isNot(dil::TokenKind kind) const { return m_kind != kind; }
+
+  bool isOneOf(dil::TokenKind kind1, dil::TokenKind kind2) const {
+    return is(kind1) || is(kind2);
+  }
+
+  template <typename... Ts> bool isOneOf(dil::TokenKind kind, Ts... Ks) const {
+    return is(kind) || isOneOf(Ks...);
+  }
+
+  uint32_t getLocation() const { return m_start_pos; }
+
+  void setValues(dil::TokenKind kind, std::string spelling, uint32_t start) {
+    m_kind = kind;
+    m_spelling = spelling;
+    m_start_pos = start;
+  }
+
+  static const std::string getTokenName(dil::TokenKind kind);
+
+private:
+  dil::TokenKind m_kind;
+  std::string m_spelling;
+  uint32_t m_start_pos; // within entire expression string
+};
+
+/// Class for doing the simple lexing required by DIL.
+class DILLexer {
+public:
+  DILLexer(llvm::StringRef dil_expr) : m_expr(dil_expr.str()) {
----------------
werat wrote:

I think if we accept `StringRef` as input, we shouldn't copy the data and work with the provided string view (and assume we don't outlive it).
If you need the lexer to own the text (and you probably don't), then accept `std::string` and move from it.

https://github.com/llvm/llvm-project/pull/123521