fix: truncate single log file upon reopening (#1143)

LWP can help identifying the corresponding thread in a debugger more easily.

.clang-tidy

@@ -2,7 +2,6 @@
 Checks:          'clang-diagnostic-*,clang-analyzer-*,google-*,modernize-*,-modernize-use-trailing-return-type,readability-*,portability-*,performance-*,bugprone-*,android-*,darwin-*,clang-analyzer-*'
 WarningsAsErrors: ''
 HeaderFilterRegex: ''
-AnalyzeTemporaryDtors: false
 FormatStyle:     file
 CheckOptions:
   - key:             cert-dcl16-c.NewSuffixes

.github/workflows/linux.yml

@@ -31,42 +31,20 @@ jobs:
       - name: Setup Dependencies
         run: |
           sudo apt-get update
-          DEBIAN_FRONTEND=noninteractive sudo apt-get install -y \
-            build-essential \
+          DEBIAN_FRONTEND=noninteractive sudo apt-get install -y --no-install-suggests --no-install-recommends \
+            g++ \
             cmake \
             gcovr \
             libgflags-dev \
+            libgmock-dev \
+            libgtest-dev \
             libunwind-dev \
             ninja-build
 
-      - name: Cache GTest
-        id: cache-gtest
-        uses: actions/cache@v4
-        with:
-          path: gtest/
-          key: ${{runner.os}}-gtest-1.11
-
-      - name: Download GTest
-        if: steps.cache-gtest.outputs.cache-hit != 'true'
-        run: |
-          wget https://github.com/google/googletest/archive/refs/tags/release-1.11.0.tar.gz
-          tar xvf release-1.11.0.tar.gz
-
-      - name: Build GTest
-        if: steps.cache-gtest.outputs.cache-hit != 'true'
-        run: |
-          cmake -S googletest-release-1.11.0 -B build-googletest \
-            -DBUILD_SHARED_LIBS=${{matrix.shared}} \
-            -DCMAKE_BUILD_TYPE=${{matrix.build_type}} \
-            -DCMAKE_INSTALL_PREFIX=${{github.workspace}}/gtest \
-            -G Ninja
-          cmake --build build-googletest --target install
-
       - name: Setup Environment
         if: matrix.build_type == 'Debug'
         run: |
           echo 'CXXFLAGS=--coverage' >> $GITHUB_ENV
-          echo 'GTest_ROOT=${{github.workspace}}/gtest' >> $GITHUB_ENV
 
       - name: Configure
         env:
@@ -131,7 +109,7 @@ jobs:
 
       - name: Upload Coverage to Codecov
         if: matrix.build_type == 'Debug'
-        uses: codecov/codecov-action@v4
+        uses: codecov/codecov-action@v5
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
           files: build_${{matrix.build_type}}/coverage.xml

.github/workflows/macos.yml

@@ -68,7 +68,7 @@ jobs:
 
       - name: Upload Coverage to Codecov
         if: matrix.build_type == 'Debug'
-        uses: codecov/codecov-action@v4
+        uses: codecov/codecov-action@v5
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
           files: build_${{matrix.build_type}}/coverage.xml

.github/workflows/windows.yml

@@ -45,18 +45,18 @@ jobs:
         uses: actions/cache@v4
         with:
           path: gtest/
-          key: ${{runner.os}}-gtest-1.11-${{matrix.lib}}-${{matrix.arch}}-${{matrix.build_type}}
+          key: ${{runner.os}}-gtest-1.14-${{matrix.lib}}-${{matrix.arch}}-${{matrix.build_type}}
 
       - name: Download GTest
         if: steps.cache-gtest.outputs.cache-hit != 'true'
         run: |
-          (New-Object System.Net.WebClient).DownloadFile("https://github.com/google/googletest/archive/refs/tags/release-1.11.0.zip", "release-1.11.0.zip")
-          Expand-Archive release-1.11.0.zip .
+          (New-Object System.Net.WebClient).DownloadFile("https://github.com/google/googletest/archive/refs/tags/v1.14.0.zip", "v1.14.0.zip")
+          Expand-Archive v1.14.0.zip .
 
       - name: Build GTest
         if: steps.cache-gtest.outputs.cache-hit != 'true'
         run: |
-          cmake -S googletest-release-1.11.0 -B build-googletest `
+          cmake -S googletest-1.14.0 -B build-googletest `
                 -A ${{matrix.arch}} `
                 -DBUILD_SHARED_LIBS=${{matrix.lib == 'shared'}} `
                 -Dgtest_force_shared_crt=ON `
@@ -234,7 +234,7 @@ jobs:
 
       - name: Upload Coverage to Codecov
         if: matrix.build_type == 'Debug'
-        uses: codecov/codecov-action@v4
+        uses: codecov/codecov-action@v5
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
           files: build_${{matrix.build_type}}/coverage.xml

.gitignore

@@ -2,3 +2,5 @@
 /build*/
 /site/
 bazel-*
+# Bzlmod lockfile
+/MODULE.bazel.lock

BUILD.bazel

@@ -17,6 +17,6 @@ platform(
     constraint_values = [
         "@platforms//cpu:x86_64",
         "@platforms//os:windows",
-        "@bazel_tools//tools/cpp:clang-cl",
+        "@rules_cc//cc/private/toolchain:clang-cl",
     ],
 )

CMakeLists.txt

@@ -64,7 +64,7 @@ set (CMAKE_VISIBILITY_INLINES_HIDDEN ON)
 
 set (CMAKE_DEBUG_POSTFIX d)
 
-find_package (GTest NO_MODULE)
+find_package (GTest 1.11 COMPONENTS GTest OPTIONAL_COMPONENTS GMock NO_MODULE)
 
 if (GTest_FOUND)
   set (HAVE_LIB_GTEST 1)
@@ -278,12 +278,12 @@ if (WITH_SYMBOLIZE)
     if (HAVE_SYMBOLIZE)
       set (HAVE_STACKTRACE 1)
     endif (HAVE_SYMBOLIZE)
+  elseif (APPLE AND HAVE_DLADDR)
+    set (HAVE_SYMBOLIZE 1)
   elseif (UNIX)
     if (HAVE_ELF_H OR HAVE_SYS_EXEC_ELF_H)
       set (HAVE_SYMBOLIZE 1)
     endif (HAVE_ELF_H OR HAVE_SYS_EXEC_ELF_H)
-  elseif (APPLE AND HAVE_DLADDR)
-    set (HAVE_SYMBOLIZE 1)
   endif (WIN32 OR CYGWIN)
 endif (WITH_SYMBOLIZE)
 

MODULE.bazel

@@ -5,3 +5,9 @@ module(
 
 bazel_dep(name = "gflags", version = "2.2.2")
 bazel_dep(name = "googletest", version = "1.14.0", dev_dependency = True)
+bazel_dep(name = "platforms", version = "0.0.10")
+bazel_dep(name = "rules_cc", version = "0.0.12")
+
+# Required for Windows clang-cl build: --extra_toolchains=@local_config_cc//:cc-toolchain-arm64_windows
+cc_configure = use_extension("@rules_cc//cc:extensions.bzl", "cc_configure_extension")
+use_repo(cc_configure, "local_config_cc")

bazel/glog.bzl

@@ -91,12 +91,14 @@ def glog_library(with_gflags = 1, **kwargs):
         # Enable declaration of _Unwind_Backtrace
         "-D_GNU_SOURCE",
         "-DHAVE_LINK_H",
+        "-DHAVE_SYMBOLIZE",  # Supported by <link.h>
     ]
 
     linux_only_copts = [
         # For utilities.h.
         "-DHAVE_EXECINFO_H",
         "-DHAVE_LINK_H",
+        "-DHAVE_SYMBOLIZE",  # Supported by <link.h>
     ]
 
     darwin_only_copts = [

docs/build.md

@@ -3,27 +3,20 @@
 ## Bazel
 
 To use glog within a project which uses the [Bazel](https://bazel.build/) build
-tool, add the following lines to your `WORKSPACE` file:
+tool, add the following lines to your `MODULE.bazel` file:
 
-``` bazel title="WORKSPACE"
-load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+``` bazel title="MODULE.bazel"
+bazel_dep(name = "glog")
 
-http_archive(
-    name = "gflags",
-    sha256 = "34af2f15cf7367513b352bdcd2493ab14ce43692d2dcd9dfc499492966c64dcf",
-    strip_prefix = "gflags-2.2.2",
-    urls = ["https://github.com/gflags/gflags/archive/v2.2.2.tar.gz"],
-)
-
-http_archive(
-    name = "com_github_google_glog",
-    sha256 = "c17d85c03ad9630006ef32c7be7c65656aba2e7e2fbfc82226b7e680c771fc88",
-    strip_prefix = "glog-0.7.1",
-    urls = ["https://github.com/google/glog/archive/v0.7.1.zip"],
+archive_override(
+    module_name = "glog",
+    urls = "https://github.com/google/glog/archive/cc0de6c200375b33d907ee7632eee2f173b33a09.tar.gz",
+    strip_prefix = "glog-cc0de6c200375b33d907ee7632eee2f173b33a09",  # Latest commit as of 2024-06-08.
+    integrity = "sha256-rUrv4EBkdc+4Wbhfxp+KoRstlj2Iw842/OpLfDq0ivg=",
 )
 ```
 
-You can then add `@com_github_google_glog//:glog` to
+You can then add `@glog//:glog` to
 the deps section of a `cc_binary` or
 `cc_library` rule, and `#!cpp #include <glog/logging.h>` to
 include it in your source code.
@@ -33,7 +26,7 @@ include it in your source code.
     cc_binary(
         name = "main",
         srcs = ["main.cc"],
-        deps = ["@com_github_google_glog//:glog"],
+        deps = ["@glog//:glog"],
     )
     ```
 

src/glog/logging.h

@@ -1419,7 +1419,7 @@ T CheckNotNull(const char* file, int line, const char* names, T&& t) {
 struct LogMessageVoidify {
   // This has to be an operator with a precedence lower than << but
   // higher than ?:
-  void operator&(std::ostream&) noexcept {}
+  constexpr void operator&(std::ostream&) const noexcept {}
 };
 
 }  // namespace internal

src/logging.cc

@@ -995,7 +995,22 @@ bool LogFileObject::CreateLogfile(const string& time_pid_string) {
   if (FLAGS_timestamp_in_logfile_name) {
     // demand that the file is unique for our timestamp (fail if it exists).
     flags = flags | O_EXCL;
+  } else {
+    // logs are written to a single file, where: a log file is created for the
+    // the first time or a file is being recreated due to exceeding max size
+
+    struct stat statbuf;
+    if (stat(filename, &statbuf) == 0) {
+      // truncate the file if it exceeds the max size
+      if ((static_cast<uint32>(statbuf.st_size) >> 20U) >= MaxLogSize()) {
+        flags |= O_TRUNC;
+      }
+
+      // update file length to sync file size
+      file_length_ = static_cast<uint32>(statbuf.st_size);
+    }
   }
+
   FileDescriptor fd{
       open(filename, flags, static_cast<mode_t>(FLAGS_logfile_mode))};
   if (!fd) return false;

src/logging_unittest.cc

@@ -110,6 +110,7 @@ static void TestLogSinkWaitTillSent();
 static void TestCHECK();
 static void TestDCHECK();
 static void TestSTREQ();
+static void TestMaxLogSizeWhenNoTimestamp();
 static void TestBasename();
 static void TestBasenameAppendWhenNoTimestamp();
 static void TestTwoProcessesWrite();
@@ -288,6 +289,7 @@ int main(int argc, char** argv) {
       MungeAndDiffTestStdout(FLAGS_test_srcdir + "/src/logging_unittest.out"));
   FLAGS_logtostdout = false;
 
+  TestMaxLogSizeWhenNoTimestamp();
   TestBasename();
   TestBasenameAppendWhenNoTimestamp();
   TestTwoProcessesWrite();
@@ -806,6 +808,47 @@ static void CheckFile(const string& name, const string& expected_string,
              << expected_string << " in " << files[0];
 }
 
+static void TestMaxLogSizeWhenNoTimestamp() {
+  fprintf(stderr, "==== Test setting max log size without timestamp\n");
+  const string dest = FLAGS_test_tmpdir + "/logging_test_max_log_size";
+  DeleteFiles(dest + "*");
+
+  auto original_max_log_size = FLAGS_max_log_size;
+  auto original_timestamp_in_logfile_name = FLAGS_timestamp_in_logfile_name;
+
+  FLAGS_max_log_size = 1;  // Set max log size to 1MB
+  FLAGS_timestamp_in_logfile_name = false;
+
+  // Set log destination
+  SetLogDestination(GLOG_INFO, dest.c_str());
+
+  // 1e4 info logs -> is about 772 KB in size
+  // 2e4 info logs -> is around 1500 KB in size -> 1.5MB
+  // If our max_log_size constraint is respected, it will truncate earlier logs
+  // and the file size will be lesser than 1MB (around 0.5MB)
+  const int num_logs = 2e4;
+  for (int i = 0; i < num_logs; i++) {
+    LOG(INFO) << "Hello world";
+  }
+  FlushLogFiles(GLOG_INFO);
+
+  // Check log file size
+  struct stat statbuf;
+  stat(dest.c_str(), &statbuf);
+
+  // Verify file size is less than the max log size limit
+  CHECK_LT(static_cast<unsigned int>(statbuf.st_size),
+           FLAGS_max_log_size << 20U);
+
+  // Reset flag values to their original values
+  FLAGS_max_log_size = original_max_log_size;
+  FLAGS_timestamp_in_logfile_name = original_timestamp_in_logfile_name;
+
+  // Release file handle for the destination file to unlock the file in Windows.
+  LogToStderr();
+  DeleteFiles(dest + "*");
+}
+
 static void TestBasename() {
   fprintf(stderr, "==== Test setting log file basename\n");
   const string dest = FLAGS_test_tmpdir + "/logging_test_basename";

src/signalhandler.cc

@@ -55,6 +55,10 @@
 #ifdef HAVE_UNISTD_H
 #  include <unistd.h>
 #endif
+#if defined(HAVE_SYS_SYSCALL_H) && defined(HAVE_SYS_TYPES_H)
+#  include <sys/syscall.h>
+#  include <sys/types.h>
+#endif
 
 namespace google {
 
@@ -216,8 +220,14 @@ void DumpSignalInfo(int signal_number, siginfo_t* siginfo) {
   std::ostringstream oss;
   oss << std::showbase << std::hex << std::this_thread::get_id();
   formatter.AppendString(oss.str().c_str());
-
+#  if defined(GLOG_OS_LINUX) && defined(HAVE_SYS_SYSCALL_H) && \
+      defined(HAVE_SYS_TYPES_H)
+  pid_t tid = syscall(SYS_gettid);
+  formatter.AppendString(" LWP ");
+  formatter.AppendUint64(static_cast<uint64>(tid), 10);
+#  endif
   formatter.AppendString(") ");
+
   // Only linux has the PID of the signal sender in si_pid.
 #  ifdef GLOG_OS_LINUX
   formatter.AppendString("from PID ");

src/symbolize.h

@@ -77,6 +77,10 @@
 #  error "symbolize.h" was not included correctly.
 #endif
 
+// We prefer to let the build system detect the availability of certain features
+// such as symbolization support. HAVE_SYMBOLIZE should therefore be defined by
+// the build system in general unless there is a good reason to perform the
+// detection using the preprocessor.
 #ifndef GLOG_NO_SYMBOLIZE_DETECTION
 #  ifndef HAVE_SYMBOLIZE
 // defined by gcc