Merge remote-tracking branch 'nixos/master' into readFile-scan-references

1 files changed, 20 insertions, 0 deletions

diff --git a/src/libmain/shared.hh b/src/libmain/shared.hh
index 0cc56d47d..3c37fd627 100644
--- a/src/libmain/shared.hh
+++ b/src/libmain/shared.hh
@@ -113,5 +113,25 @@ struct PrintFreed
 /* Install a SIGSEGV handler to detect stack overflows. */
 void detectStackOverflow();
 
+/* Pluggable behavior to run in case of a stack overflow.
+
+   Default value: defaultStackOverflowHandler.
+
+   This is called by the handler installed by detectStackOverflow().
+
+   This gives Nix library consumers a limit opportunity to report the error
+   condition. The handler should exit the process.
+   See defaultStackOverflowHandler() for a reference implementation.
+
+   NOTE: Use with diligence, because this runs in the signal handler, with very
+   limited stack space and a potentially a corrupted heap, all while the failed
+   thread is blocked indefinitely. All functions called must be reentrant. */
+extern std::function<void(siginfo_t * info, void * ctx)> stackOverflowHandler;
+
+/* The default, robust implementation of stackOverflowHandler.
+
+   Prints an error message directly to stderr using a syscall instead of the
+   logger. Exits the process immediately after. */
+void defaultStackOverflowHandler(siginfo_t * info, void * ctx);
 
 }