[Lldb-commits] [lldb] [lldb] Read Checksum from DWARF line tables (PR #71458)

via lldb-commits lldb-commits at lists.llvm.org
Mon Nov 6 15:09:49 PST 2023


llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-lldb

Author: Jonas Devlieghere (JDevlieghere)

<details>
<summary>Changes</summary>

Read the MD5 checksum from DWARF line tables and store it in the
corresponding support files.

---
Full diff: https://github.com/llvm/llvm-project/pull/71458.diff


9 Files Affected:

- (added) lldb/include/lldb/Utility/Checksum.h (+36) 
- (modified) lldb/include/lldb/Utility/FileSpec.h (+17-2) 
- (modified) lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp (+8-1) 
- (modified) lldb/source/Utility/CMakeLists.txt (+1) 
- (added) lldb/source/Utility/Checksum.cpp (+46) 
- (modified) lldb/source/Utility/FileSpec.cpp (+6-3) 
- (modified) lldb/unittests/Utility/CMakeLists.txt (+1) 
- (added) lldb/unittests/Utility/ChecksumTest.cpp (+57) 
- (modified) lldb/unittests/Utility/FileSpecTest.cpp (+21-37) 


``````````diff
diff --git a/lldb/include/lldb/Utility/Checksum.h b/lldb/include/lldb/Utility/Checksum.h
new file mode 100644
index 000000000000000..90a579b247636ac
--- /dev/null
+++ b/lldb/include/lldb/Utility/Checksum.h
@@ -0,0 +1,36 @@
+//===-- Checksum.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_UTILITY_CHECKSUM_H
+#define LLDB_UTILITY_CHECKSUM_H
+
+#include "llvm/Support/MD5.h"
+
+namespace lldb_private {
+class Checksum {
+public:
+  static llvm::MD5::MD5Result sentinel;
+
+  Checksum(llvm::MD5::MD5Result md5 = sentinel);
+  Checksum(const Checksum &checksum);
+  Checksum &operator=(const Checksum &checksum);
+
+  explicit operator bool() const;
+  bool operator==(const Checksum &checksum) const;
+  bool operator!=(const Checksum &checksum) const;
+
+  std::string digest() const;
+
+private:
+  void SetMD5(llvm::MD5::MD5Result);
+
+  llvm::MD5::MD5Result m_checksum;
+};
+} // namespace lldb_private
+
+#endif // LLDB_UTILITY_CHECKSUM_H
diff --git a/lldb/include/lldb/Utility/FileSpec.h b/lldb/include/lldb/Utility/FileSpec.h
index f06a8543a056e87..29506b01c56d40b 100644
--- a/lldb/include/lldb/Utility/FileSpec.h
+++ b/lldb/include/lldb/Utility/FileSpec.h
@@ -13,15 +13,18 @@
 #include <optional>
 #include <string>
 
+#include "lldb/Utility/Checksum.h"
 #include "lldb/Utility/ConstString.h"
 
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/FormatVariadic.h"
+#include "llvm/Support/MD5.h"
 #include "llvm/Support/Path.h"
 
 #include <cstddef>
 #include <cstdint>
+#include <optional>
 
 namespace lldb_private {
 class Stream;
@@ -72,7 +75,8 @@ class FileSpec {
   ///     The style of the path
   ///
   /// \see FileSpec::SetFile (const char *path)
-  explicit FileSpec(llvm::StringRef path, Style style = Style::native);
+  explicit FileSpec(llvm::StringRef path, Style style = Style::native,
+                    const Checksum &checksum = {});
 
   explicit FileSpec(llvm::StringRef path, const llvm::Triple &triple);
 
@@ -362,7 +366,11 @@ class FileSpec {
   ///
   /// \param[in] style
   ///     The style for the given path.
-  void SetFile(llvm::StringRef path, Style style);
+  ///
+  /// \param[in] checksum
+  ///     The checksum for the given path.
+  void SetFile(llvm::StringRef path, Style style,
+               const Checksum &checksum = {});
 
   /// Change the file specified with a new path.
   ///
@@ -420,6 +428,9 @@ class FileSpec {
   ///   The lifetime of the StringRefs is tied to the lifetime of the FileSpec.
   std::vector<llvm::StringRef> GetComponents() const;
 
+  /// Return the checksum for this FileSpec or all zeros if there is none.
+  const Checksum &GetChecksum() const { return m_checksum; };
+
 protected:
   // Convenience method for setting the file without changing the style.
   void SetFile(llvm::StringRef path);
@@ -427,6 +438,7 @@ class FileSpec {
   /// Called anytime m_directory or m_filename is changed to clear any cached
   /// state in this object.
   void PathWasModified() {
+    m_checksum = Checksum();
     m_is_resolved = false;
     m_absolute = Absolute::Calculate;
   }
@@ -443,6 +455,9 @@ class FileSpec {
   /// The unique'd filename path.
   ConstString m_filename;
 
+  /// The optional MD5 checksum of the file.
+  Checksum m_checksum;
+
   /// True if this path has been resolved.
   mutable bool m_is_resolved = false;
 
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
index aabd83a194932ff..79d44bce3d663b6 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp
@@ -229,8 +229,15 @@ ParseSupportFilesFromPrologue(const lldb::ModuleSP &module,
         remapped_file = std::move(*file_path);
     }
 
+    Checksum checksum;
+    if (prologue.ContentTypes.HasMD5) {
+      const llvm::DWARFDebugLine::FileNameEntry &file_name_entry =
+          prologue.getFileNameEntry(idx);
+      checksum = file_name_entry.Checksum;
+    }
+
     // Unconditionally add an entry, so the indices match up.
-    support_files.EmplaceBack(remapped_file, style);
+    support_files.EmplaceBack(remapped_file, style, checksum);
   }
 
   return support_files;
diff --git a/lldb/source/Utility/CMakeLists.txt b/lldb/source/Utility/CMakeLists.txt
index 16afab1113a970c..a3b0a405b4133f6 100644
--- a/lldb/source/Utility/CMakeLists.txt
+++ b/lldb/source/Utility/CMakeLists.txt
@@ -29,6 +29,7 @@ add_lldb_library(lldbUtility NO_INTERNAL_DEPENDENCIES
   Args.cpp
   Baton.cpp
   Broadcaster.cpp
+  Checksum.cpp
   CompletionRequest.cpp
   Connection.cpp
   ConstString.cpp
diff --git a/lldb/source/Utility/Checksum.cpp b/lldb/source/Utility/Checksum.cpp
new file mode 100644
index 000000000000000..70167e497a526c4
--- /dev/null
+++ b/lldb/source/Utility/Checksum.cpp
@@ -0,0 +1,46 @@
+//===-- Checksum.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/Utility/Checksum.h"
+#include "llvm/ADT/SmallString.h"
+
+using namespace lldb_private;
+
+Checksum::Checksum(llvm::MD5::MD5Result md5) { SetMD5(md5); }
+
+Checksum::Checksum(const Checksum &checksum) { SetMD5(checksum.m_checksum); }
+
+Checksum &Checksum::operator=(const Checksum &checksum) {
+  SetMD5(checksum.m_checksum);
+  return *this;
+}
+
+void Checksum::SetMD5(llvm::MD5::MD5Result md5) {
+  std::uninitialized_copy_n(md5.begin(), 16, m_checksum.begin());
+}
+
+Checksum::operator bool() const {
+  return !std::equal(m_checksum.begin(), m_checksum.end(), sentinel.begin());
+}
+
+bool Checksum::operator==(const Checksum &checksum) const {
+  return std::equal(m_checksum.begin(), m_checksum.end(),
+                    checksum.m_checksum.begin());
+}
+
+bool Checksum::operator!=(const Checksum &checksum) const {
+  return !std::equal(m_checksum.begin(), m_checksum.end(),
+                     checksum.m_checksum.begin());
+}
+
+std::string Checksum::digest() const {
+  return std::string(m_checksum.digest().str());
+}
+
+llvm::MD5::MD5Result Checksum::sentinel = {0, 0, 0, 0, 0, 0, 0, 0,
+                                           0, 0, 0, 0, 0, 0, 0, 0};
diff --git a/lldb/source/Utility/FileSpec.cpp b/lldb/source/Utility/FileSpec.cpp
index eb34ef97cea0b2f..4bbfbb7c1fab5e6 100644
--- a/lldb/source/Utility/FileSpec.cpp
+++ b/lldb/source/Utility/FileSpec.cpp
@@ -68,8 +68,9 @@ void Denormalize(llvm::SmallVectorImpl<char> &path, FileSpec::Style style) {
 FileSpec::FileSpec() : m_style(GetNativeStyle()) {}
 
 // Default constructor that can take an optional full path to a file on disk.
-FileSpec::FileSpec(llvm::StringRef path, Style style) : m_style(style) {
-  SetFile(path, style);
+FileSpec::FileSpec(llvm::StringRef path, Style style, const Checksum &checksum)
+    : m_checksum(checksum), m_style(style) {
+  SetFile(path, style, checksum);
 }
 
 FileSpec::FileSpec(llvm::StringRef path, const llvm::Triple &triple)
@@ -171,9 +172,11 @@ void FileSpec::SetFile(llvm::StringRef pathname) { SetFile(pathname, m_style); }
 // Update the contents of this object with a new path. The path will be split
 // up into a directory and filename and stored as uniqued string values for
 // quick comparison and efficient memory usage.
-void FileSpec::SetFile(llvm::StringRef pathname, Style style) {
+void FileSpec::SetFile(llvm::StringRef pathname, Style style,
+                       const Checksum &checksum) {
   Clear();
   m_style = (style == Style::native) ? GetNativeStyle() : style;
+  m_checksum = checksum;
 
   if (pathname.empty())
     return;
diff --git a/lldb/unittests/Utility/CMakeLists.txt b/lldb/unittests/Utility/CMakeLists.txt
index 5c7003a156813dc..097dae860b15911 100644
--- a/lldb/unittests/Utility/CMakeLists.txt
+++ b/lldb/unittests/Utility/CMakeLists.txt
@@ -4,6 +4,7 @@ add_lldb_unittest(UtilityTests
   OptionsWithRawTest.cpp
   ArchSpecTest.cpp
   BroadcasterTest.cpp
+  ChecksumTest.cpp
   ConstStringTest.cpp
   CompletionRequestTest.cpp
   DataBufferTest.cpp
diff --git a/lldb/unittests/Utility/ChecksumTest.cpp b/lldb/unittests/Utility/ChecksumTest.cpp
new file mode 100644
index 000000000000000..7537d30b5ff5b84
--- /dev/null
+++ b/lldb/unittests/Utility/ChecksumTest.cpp
@@ -0,0 +1,57 @@
+//===-- ChecksumTest.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 "gtest/gtest.h"
+
+#include "lldb/Utility/Checksum.h"
+
+using namespace lldb_private;
+
+static llvm::MD5::MD5Result hash1 = {0, 1, 2,  3,  4,  5,  6,  7,
+                                     8, 9, 10, 11, 12, 13, 14, 15};
+
+static llvm::MD5::MD5Result hash2 = {0, 1, 2,  3,  4,  5,  6,  7,
+                                     8, 9, 10, 11, 12, 13, 14, 15};
+
+static llvm::MD5::MD5Result hash3 = {8, 9, 10, 11, 12, 13, 14, 15,
+                                     0, 1, 2,  3,  4,  5,  6,  7};
+
+TEST(ChecksumTest, TestConstructor) {
+  Checksum checksum1;
+  EXPECT_FALSE(static_cast<bool>(checksum1));
+  EXPECT_EQ(checksum1, Checksum());
+
+  Checksum checksum2 = Checksum(hash1);
+  EXPECT_EQ(checksum2, Checksum(hash1));
+
+  Checksum checksum3(checksum2);
+  EXPECT_EQ(checksum3, Checksum(hash1));
+}
+
+TEST(ChecksumTest, TestCopyConstructor) {
+  Checksum checksum1;
+  EXPECT_FALSE(static_cast<bool>(checksum1));
+  EXPECT_EQ(checksum1, Checksum());
+
+  Checksum checksum2 = checksum1;
+  EXPECT_EQ(checksum2, checksum1);
+
+  Checksum checksum3(checksum1);
+  EXPECT_EQ(checksum3, checksum1);
+}
+
+TEST(ChecksumTest, TestMD5) {
+  Checksum checksum1(hash1);
+  EXPECT_TRUE(static_cast<bool>(checksum1));
+
+  // Make sure two checksums with the same underlying hashes are the same.
+  EXPECT_EQ(Checksum(hash1), Checksum(hash2));
+
+  // Make sure two checksums with different underlying hashes are different.
+  EXPECT_NE(Checksum(hash1), Checksum(hash3));
+}
diff --git a/lldb/unittests/Utility/FileSpecTest.cpp b/lldb/unittests/Utility/FileSpecTest.cpp
index 2a62f6b1e76120f..ebe7bde7d9c2169 100644
--- a/lldb/unittests/Utility/FileSpecTest.cpp
+++ b/lldb/unittests/Utility/FileSpecTest.cpp
@@ -28,8 +28,8 @@ TEST(FileSpecTest, FileAndDirectoryComponents) {
 
   FileSpec fs_windows("F:\\bar", FileSpec::Style::windows);
   EXPECT_STREQ("F:\\bar", fs_windows.GetPath().c_str());
-  // EXPECT_STREQ("F:\\", fs_windows.GetDirectory().GetPath().c_str()); // It returns
-  // "F:/"
+  // EXPECT_STREQ("F:\\", fs_windows.GetDirectory().GetPath().c_str()); // It
+  // returns "F:/"
   EXPECT_STREQ("bar", fs_windows.GetFilename().GetCString());
 
   FileSpec fs_posix_root("/", FileSpec::Style::posix);
@@ -297,45 +297,18 @@ TEST(FileSpecTest, FormatFileSpec) {
 
 TEST(FileSpecTest, IsRelative) {
   llvm::StringRef not_relative[] = {
-    "/",
-    "/a",
-    "/a/",
-    "/a/b",
-    "/a/b/",
-    "//",
-    "//a/",
-    "//a/b",
-    "//a/b/",
-    "~",
-    "~/",
-    "~/a",
-    "~/a/",
-    "~/a/b",
-    "~/a/b/",
-    "/foo/.",
-    "/foo/..",
-    "/foo/../",
-    "/foo/../.",
+      "/",      "/a",     "/a/",     "/a/b",     "/a/b/",     "//",   "//a/",
+      "//a/b",  "//a/b/", "~",       "~/",       "~/a",       "~/a/", "~/a/b",
+      "~/a/b/", "/foo/.", "/foo/..", "/foo/../", "/foo/../.",
   };
-  for (const auto &path: not_relative) {
+  for (const auto &path : not_relative) {
     SCOPED_TRACE(path);
     EXPECT_FALSE(PosixSpec(path).IsRelative());
   }
   llvm::StringRef is_relative[] = {
-    ".",
-    "./",
-    ".///",
-    "a",
-    "./a",
-    "./a/",
-    "./a/",
-    "./a/b",
-    "./a/b/",
-    "../foo",
-    "foo/bar.c",
-    "./foo/bar.c"
-  };
-  for (const auto &path: is_relative) {
+      ".",    "./",    ".///",   "a",      "./a",       "./a/",
+      "./a/", "./a/b", "./a/b/", "../foo", "foo/bar.c", "./foo/bar.c"};
+  for (const auto &path : is_relative) {
     SCOPED_TRACE(path);
     EXPECT_TRUE(PosixSpec(path).IsRelative());
   }
@@ -421,7 +394,6 @@ TEST(FileSpecTest, Match) {
 
   EXPECT_TRUE(Match("", "/foo/bar"));
   EXPECT_TRUE(Match("", ""));
-
 }
 
 TEST(FileSpecTest, TestAbsoluteCaching) {
@@ -534,3 +506,15 @@ TEST(FileSpecTest, TestGetComponents) {
     EXPECT_EQ(file_spec.GetComponents(), pair.second);
   }
 }
+
+TEST(FileSpecTest, TestChecksum) {
+  Checksum checksum({0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15});
+  FileSpec file_spec("/foo/bar", FileSpec::Style::posix, checksum);
+  EXPECT_TRUE(static_cast<bool>(file_spec.GetChecksum()));
+  EXPECT_EQ(file_spec.GetChecksum(), checksum);
+
+  FileSpec copy = file_spec;
+
+  EXPECT_TRUE(static_cast<bool>(copy.GetChecksum()));
+  EXPECT_EQ(file_spec.GetChecksum(), copy.GetChecksum());
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/71458


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