- abe587c2360b21f085b7d65a77d840015bc04cf6 Factor an internal interface into its own header, as it w... by Greg Falcon <gfalcon@google.com>

  - 2201f1644336e64280dbd20207d8fbc3bfea2bf4 Internal change. by Abseil Team <absl-team@google.com>
  - 94e6b5b20d2cc754c99a18c575a4f1f3cd1f28d4 Rename no_throw_ctor to nothrow_ctor to match the standar... by Abseil Team <absl-team@google.com>
  - 86aa34d2129c4914c5133b7b619480aae786288e Update header files in debugging target by Tom Manshreck <shreck@google.com>
  - ed234519ced458724a7267b8fdf184eaae1c97c7 Remove CMAKE_CXX_WARNING_VLA from our c++ flags in the cm... by Jon Cohen <cohenjon@google.com>

GitOrigin-RevId: abe587c2360b21f085b7d65a77d840015bc04cf6
Change-Id: I92f9301c69419d3830c358b88984967185aa33f6

1 files changed, 70 insertions, 8 deletions

diff --git a/absl/debugging/symbolize.h b/absl/debugging/symbolize.h
index 073a4479d9c4..24e6e6471c65 100644
--- a/absl/debugging/symbolize.h
+++ b/absl/debugging/symbolize.h
@@ -11,7 +11,44 @@
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
-
+//
+// -----------------------------------------------------------------------------
+// File: symbolize.h
+// -----------------------------------------------------------------------------
+//
+// This file configures the Abseil symbolizer for use in converting instruction
+// pointer addresses (program counters) into human-readable names (function
+// calls, etc.) within Abseil code.
+//
+// The symbolizer may be invoked from several sources:
+//
+//   * Implicitly, through the installation of an Abseil failure signal handler.
+//     (See failure_signal_handler.h for more information.)
+//   * By calling `Symbolize()` directly on a program counter you obtain through
+//     `absl::GetStackTrace()` or `absl::GetStackFrames()`. (See stacktrace.h
+//     for more information.
+//   * By calling `Symbolize()` directly on a program counter you obtain through
+//     other means (which would be platform-dependent).
+//
+// In all of the above cases, the symbolizer must first be initialized before
+// any program counter values can be symbolized. If you are installing a failure
+// signal handler, initialize the symbolizer before you do so.
+//
+// Example:
+//
+//   int main(int argc, char** argv) {
+//     // Initialize the Symbolizer before installing the failure signal handler
+//     absl::InitializeSymbolizer(argv[0]);
+//
+//     // Now you may install the failure signal handler
+//     absl::FailureSignalHandlerOptions options;
+//     absl::InstallFailureSignalHandler(options);
+//
+//     // Start running your main program
+//     ...
+//     return 0;
+//  }
+//
 #ifndef ABSL_DEBUGGING_SYMBOLIZE_H_
 #define ABSL_DEBUGGING_SYMBOLIZE_H_
 
@@ -19,15 +56,40 @@
 
 namespace absl {
 
-// Initializes this module. Symbolize() may fail prior calling this function.
-// `argv0` is the path to this program, which is usually obtained in main()
-// though argv[0].
+// InitializeSymbolizer()
+//
+// Initializes the program counter symbolizer, given the path of the program
+// (typically obtained through `main()`s `argv[0]`). The Abseil symbolizer
+// allows you to read program counters (instruction pointer values) using their
+// human-readable names within output such as stack traces.
+//
+// Example:
+//
+// int main(int argc, char *argv[]) {
+//   absl::InitializeSymbolizer(argv[0]);
+//   // Now you can use the symbolizer
+// }
 void InitializeSymbolizer(const char* argv0);
 
-// Symbolizes a program counter.  On success, returns true and write the
-// symbol name to "out".  The symbol name is demangled if possible
-// (supports symbols generated by GCC 3.x or newer), may be truncated, and
-// will be '\0' terminated.  Otherwise, returns false.
+// Symbolize()
+//
+// Symbolizes a program counter (instruction pointer value) `pc` and, on
+// success, writes the name to `out`. The symbol name is demangled, if possible.
+// Note that the symbolized name may be truncated and will be NUL-terminated.
+// Demangling is supported for symbols generated by GCC 3.x or newer). Returns
+// `false` on failure.
+//
+// Example:
+//
+//   // Print a program counter and its symbol name.
+//   static void DumpPCAndSymbol(void *pc) {
+//     char tmp[1024];
+//     const char *symbol = "(unknown)";
+//     if (absl::Symbolize(pc, tmp, sizeof(tmp))) {
+//       symbol = tmp;
+//     }
+//     absl::PrintF("%*p  %s\n", pc, symbol);
+//  }
 bool Symbolize(const void *pc, char *out, int out_size);
 
 }  // namespace absl