diff options
| -rw-r--r-- | src/libutil/error.cc | 5 | ||||
| -rw-r--r-- | src/libutil/error.hh | 4 | ||||
| -rw-r--r-- | src/libutil/util.cc | 17 |
3 files changed, 26 insertions, 0 deletions
diff --git a/src/libutil/error.cc b/src/libutil/error.cc index c9d61942a..4a1b346ef 100644 --- a/src/libutil/error.cc +++ b/src/libutil/error.cc @@ -14,6 +14,11 @@ void BaseError::addTrace(std::shared_ptr<AbstractPos> && e, hintformat hint, boo err.traces.push_front(Trace { .pos = std::move(e), .hint = hint, .frame = frame }); } +void throwExceptionSelfCheck(){ + // This is meant to be caught in initLibUtil() + throw SysError("C++ exception handling is broken. This would appear to be a problem with the way Nix was compiled and/or linked and/or loaded."); +} + // c++ std::exception descendants must have a 'const char* what()' function. // This stringifies the error and caches it for use by what(), or similarly by msg(). const std::string & BaseError::calcWhat() const diff --git a/src/libutil/error.hh b/src/libutil/error.hh index 6a0923081..be5c5e252 100644 --- a/src/libutil/error.hh +++ b/src/libutil/error.hh @@ -214,4 +214,8 @@ public: } }; +/** Throw an exception for the purpose of checking that exception handling works; see 'initLibUtil()'. + */ +void throwExceptionSelfCheck(); + } diff --git a/src/libutil/util.cc b/src/libutil/util.cc index 26f9dc8a8..f24a6e165 100644 --- a/src/libutil/util.cc +++ b/src/libutil/util.cc @@ -48,6 +48,23 @@ extern char * * environ __attribute__((weak)); namespace nix { void initLibUtil() { + // Check that exception handling works. Exception handling has been observed + // not to work on darwin when the linker flags aren't quite right. + // In this case we don't want to expose the user to some unrelated uncaught + // exception, but rather tell them exactly that exception handling is + // broken. + // When exception handling fails, the message tends to be printed by the + // C++ runtime, followed by an abort. + // For example on macOS we might see an error such as + // libc++abi: terminating with uncaught exception of type nix::SysError: error: C++ exception handling is broken. This would appear to be a problem with the way Nix was compiled and/or linked and/or loaded. + bool caught = false; + try { + throwExceptionSelfCheck(); + } catch (nix::Error _e) { + caught = true; + } + // This is not actually the main point of this check, but let's make sure anyway: + assert(caught); } std::optional<std::string> getEnv(const std::string & key) |