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

[Pavel Labath via lldb-commits]

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@@ -0,0 +1,205 @@
+//===-- DILLexer.cpp ------------------------------------------------------===//
+//
+// 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
+//
+// This implements the recursive descent parser for the Data Inspection
+// Language (DIL), and its helper functions, which will eventually underlie the
+// 'frame variable' command. The language that this parser recognizes is
+// described in lldb/docs/dil-expr-lang.ebnf
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/ValueObject/DILLexer.h"
+#include "llvm/ADT/StringMap.h"
+
+namespace lldb_private {
+
+namespace dil {
+
+// For fast keyword lookup. More keywords will be added later.
+const llvm::StringMap<dil::TokenKind> Keywords = {
+    {"namespace", dil::TokenKind::kw_namespace},
+};
+
+const std::string DILToken::getTokenName(dil::TokenKind kind) {
+  switch (kind) {
+  case dil::TokenKind::coloncolon:
+    return "coloncolon";
+  case dil::TokenKind::eof:
+    return "eof";
+  case dil::TokenKind::identifier:
+    return "identifier";
+  case dil::TokenKind::kw_namespace:
+    return "namespace";
+  case dil::TokenKind::l_paren:
+    return "l_paren";
+  case dil::TokenKind::r_paren:
+    return "r_paren";
+  case dil::TokenKind::unknown:
+    return "unknown";
+  default:
+    return "token_name";
+  }
+}
+
+static bool Is_Letter(char c) {
+  if (('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z'))
+    return true;
+  return false;
+}
+
+static bool Is_Digit(char c) { return ('0' <= c && c <= '9'); }
+
+// A word starts with a letter, underscore, or dollar sign, followed by
+// letters ('a'..'z','A'..'Z'), digits ('0'..'9'), and/or  underscores.
+bool DILLexer::Is_Word(std::string::iterator start, uint32_t &length) {
+  bool done = false;
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labath wrote:

Yes, but you break out of the loop as soon as you set it to true. (I don't think the meaning of the code would change if you just deleted all references to the variable.

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