[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 +1,192 @@
+//===-- DILLexerTests.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
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/ValueObject/DILLexer.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Testing/Support/Error.h"
+#include "gtest/gtest.h"
+#include <string>
+
+using llvm::StringRef;
+
+std::vector<std::pair<lldb_private::dil::Token::Kind, std::string>>
+ExtractTokenData(lldb_private::dil::DILLexer &lexer) {
+  std::vector<std::pair<lldb_private::dil::Token::Kind, std::string>> data;
+  if (lexer.NumLexedTokens() == 0)
+    return data;
+
+  lexer.ResetTokenIdx(UINT_MAX);
+  do {
+    lexer.Advance();
+    lldb_private::dil::Token tok = lexer.GetCurrentToken();
+    data.push_back(std::make_pair(tok.GetKind(), tok.GetSpelling()));
+  } while (data.back().first != lldb_private::dil::Token::eof);
+  return data;
+}
+
+TEST(DILLexerTests, SimpleTest) {
+  StringRef input_expr("simple_var");
+  uint32_t tok_len = 10;
+  llvm::Expected<lldb_private::dil::DILLexer> maybe_lexer =
+      lldb_private::dil::DILLexer::Create(input_expr);
+  ASSERT_THAT_EXPECTED(maybe_lexer, llvm::Succeeded());
+  lldb_private::dil::DILLexer lexer(*maybe_lexer);
+  lldb_private::dil::Token token =
+      lldb_private::dil::Token(lldb_private::dil::Token::unknown, "", 0);
+  EXPECT_EQ(token.GetKind(), lldb_private::dil::Token::unknown);
+
+  lexer.Advance();
+  token = lexer.GetCurrentToken();
+  EXPECT_EQ(token.GetKind(), lldb_private::dil::Token::identifier);
+  EXPECT_EQ(token.GetSpelling(), "simple_var");
+  EXPECT_EQ(token.GetSpelling().size(), tok_len);
+  lexer.Advance();
+  token = lexer.GetCurrentToken();
+  EXPECT_EQ(token.GetKind(), lldb_private::dil::Token::eof);
+}
+
+TEST(DILLexerTests, TokenKindTest) {
+  StringRef input_expr("namespace");
+  llvm::Expected<lldb_private::dil::DILLexer> maybe_lexer =
+      lldb_private::dil::DILLexer::Create(input_expr);
+  ASSERT_THAT_EXPECTED(maybe_lexer, llvm::Succeeded());
+  lldb_private::dil::DILLexer lexer(*maybe_lexer);
+  lldb_private::dil::Token token =
+      lldb_private::dil::Token(lldb_private::dil::Token::unknown, "", 0);
+  lexer.Advance();
+  token = lexer.GetCurrentToken();
+
+  EXPECT_TRUE(token.Is(lldb_private::dil::Token::identifier));
+  EXPECT_FALSE(token.Is(lldb_private::dil::Token::l_paren));
+  EXPECT_TRUE(token.IsOneOf(lldb_private::dil::Token::eof,
+                            lldb_private::dil::Token::identifier));
+  EXPECT_FALSE(token.IsOneOf(
+      lldb_private::dil::Token::l_paren, lldb_private::dil::Token::r_paren,
+      lldb_private::dil::Token::coloncolon, lldb_private::dil::Token::eof));
+}
+
+TEST(DILLexerTests, LookAheadTest) {
+  StringRef input_expr("(anonymous namespace)::some_var");
+  llvm::Expected<lldb_private::dil::DILLexer> maybe_lexer =
+      lldb_private::dil::DILLexer::Create(input_expr);
+  ASSERT_THAT_EXPECTED(maybe_lexer, llvm::Succeeded());
+  lldb_private::dil::DILLexer lexer(*maybe_lexer);
+  lldb_private::dil::Token token =
+      lldb_private::dil::Token(lldb_private::dil::Token::unknown, "", 0);
+  uint32_t expect_loc = 23;
+  lexer.Advance();
+  token = lexer.GetCurrentToken();
+
+  // Current token is '('; check the next 4 tokens, to make
+  // sure they are the identifier 'anonymous', the identifier 'namespace'
+  // ')' and '::', in that order.
+  EXPECT_EQ(token.GetKind(), lldb_private::dil::Token::l_paren);
+  EXPECT_EQ(lexer.LookAhead(1).GetKind(), lldb_private::dil::Token::identifier);
+  EXPECT_EQ(lexer.LookAhead(1).GetSpelling(), "anonymous");
+  EXPECT_EQ(lexer.LookAhead(2).GetKind(), lldb_private::dil::Token::identifier);
+  EXPECT_EQ(lexer.LookAhead(2).GetSpelling(), "namespace");
+  EXPECT_EQ(lexer.LookAhead(3).GetKind(), lldb_private::dil::Token::r_paren);
+  EXPECT_EQ(lexer.LookAhead(4).GetKind(), lldb_private::dil::Token::coloncolon);
+
+  // Our current index should still be 0, as we only looked ahead; we are still
+  // officially on the '('.
+  EXPECT_EQ(lexer.GetCurrentTokenIdx(), (uint32_t)0);
+
+  // Accept the 'lookahead', so our current token is '::', which has the index
+  // 4 in our vector of tokens (which starts at zero).
+  lexer.Advance(4);
+  token = lexer.GetCurrentToken();
+  EXPECT_EQ(token.GetKind(), lldb_private::dil::Token::coloncolon);
+  EXPECT_EQ(lexer.GetCurrentTokenIdx(), (uint32_t)4);
+
+  lexer.Advance();
+  token = lexer.GetCurrentToken();
+  EXPECT_EQ(token.GetKind(), lldb_private::dil::Token::identifier);
+  EXPECT_EQ(token.GetSpelling(), "some_var");
+  EXPECT_EQ(lexer.GetCurrentTokenIdx(), (uint32_t)5);
+  // Verify we've advanced our position counter (lexing location) in the
+  // input 23 characters (the length of '(anonymous namespace)::'.
+  EXPECT_EQ(token.GetLocation(), expect_loc);
+
+  lexer.Advance();
+  token = lexer.GetCurrentToken();
+  EXPECT_EQ(token.GetKind(), lldb_private::dil::Token::eof);
+}
+
+TEST(DILLexerTests, MultiTokenLexTest) {
+  StringRef input_expr("This string has (several ) ::identifiers");
+  llvm::Expected<lldb_private::dil::DILLexer> maybe_lexer =
+      lldb_private::dil::DILLexer::Create(input_expr);
+  ASSERT_THAT_EXPECTED(maybe_lexer, llvm::Succeeded());
+  lldb_private::dil::DILLexer lexer(*maybe_lexer);
+  lldb_private::dil::Token token =
+      lldb_private::dil::Token(lldb_private::dil::Token::unknown, "", 0);
+
+  std::vector<std::pair<lldb_private::dil::Token::Kind, std::string>>
+      lexer_tokens_data = ExtractTokenData(lexer);
+
+  EXPECT_THAT(
+      lexer_tokens_data,
+      testing::ElementsAre(
+          testing::Pair(lldb_private::dil::Token::identifier, "This"),
+          testing::Pair(lldb_private::dil::Token::identifier, "string"),
+          testing::Pair(lldb_private::dil::Token::identifier, "has"),
+          testing::Pair(lldb_private::dil::Token::l_paren, "("),
+          testing::Pair(lldb_private::dil::Token::identifier, "several"),
+          testing::Pair(lldb_private::dil::Token::r_paren, ")"),
+          testing::Pair(lldb_private::dil::Token::coloncolon, "::"),
+          testing::Pair(lldb_private::dil::Token::identifier, "identifiers"),
+          testing::Pair(lldb_private::dil::Token::eof, "")));
+  lexer.Advance();
+  token = lexer.GetCurrentToken();
+  EXPECT_EQ(token.GetSpelling(), "");
+  EXPECT_EQ(token.GetKind(), lldb_private::dil::Token::eof);
+}
+
+TEST(DILLexerTests, IdentifiersTest) {
+  std::vector<std::string> valid_identifiers = {
+      "$My_name1", "$pc",  "abcd", "ab cd", "_",      "_a",       "_a_",
+      "a_b",       "this", "self", "a",     "MyName", "namespace"};
+  std::vector<std::string> invalid_identifiers = {"234", "2a",      "2",
+                                                  "$",   "1MyName", ""};
+
+  // Verify that all of the valid identifiers come out as identifier tokens.
+  for (auto &str : valid_identifiers) {
+    SCOPED_TRACE(str);
+    llvm::Expected<lldb_private::dil::DILLexer> maybe_lexer =
+        lldb_private::dil::DILLexer::Create(str);
+    ASSERT_THAT_EXPECTED(maybe_lexer, llvm::Succeeded());
+    lldb_private::dil::DILLexer lexer(*maybe_lexer);
+    lldb_private::dil::Token token =
+        lldb_private::dil::Token(lldb_private::dil::Token::unknown, "", 0);
+    lexer.Advance();
+    token = lexer.GetCurrentToken();
+    EXPECT_EQ(token.GetKind(), lldb_private::dil::Token::identifier);
+  }
+
+  // Verify that none of the invalid identifiers come out as identifier tokens.
+  for (auto &str : invalid_identifiers) {
+    SCOPED_TRACE(str);
+    llvm::Expected<lldb_private::dil::DILLexer> maybe_lexer =
+        lldb_private::dil::DILLexer::Create(str);
+    if (!maybe_lexer) {
----------------
labath wrote:

Just in case the problem was that some of these cases can fail (return an error) and others can do something else (e.g return EOF), I'm going to add this. You can drop the loop and spell out the expectations for each string separately. The reason the loop is there is because the logic was tedious to write, but when that the check is a single statement, it doesn't bring much to game.

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