1 files changed, 15 insertions, 0 deletions
diff --git a/absl/debugging/internal/examine_stack.h b/absl/debugging/internal/examine_stack.h
index 39336913..61f0056f 100644
--- a/absl/debugging/internal/examine_stack.h
+++ b/absl/debugging/internal/examine_stack.h
@@ -23,6 +23,21 @@ namespace absl {
 ABSL_NAMESPACE_BEGIN
 namespace debugging_internal {
 
+// Type of function used for printing in stack trace dumping, etc.
+// We avoid closures to keep things simple.
+typedef void OutputWriter(const char*, void*);
+
+// RegisterDebugStackTraceHook() allows to register a single routine
+// `hook` that is called each time DumpStackTrace() is called.
+// `hook` may be called from a signal handler.
+typedef void (*SymbolizeUrlEmitter)(void* const stack[], int depth,
+                                    OutputWriter writer, void* writer_arg);
+
+// Registration of SymbolizeUrlEmitter for use inside of a signal handler.
+// This is inherently unsafe and must be signal safe code.
+void RegisterDebugStackTraceHook(SymbolizeUrlEmitter hook);
+SymbolizeUrlEmitter GetDebugStackTraceHook();
+
 // Returns the program counter from signal context, or nullptr if
 // unknown. `vuc` is a ucontext_t*. We use void* to avoid the use of
 // ucontext_t on non-POSIX systems.