core/luajit/context_test.hh

@@ -36,8 +36,8 @@ class ContextFixture : public ::testing::TestWithParam<Context::Kind> {
         task(param_);
       } catch (const Exception& e) {
         std::cerr
-            << "unexpected exception while async task execution: " << e.what()
-            << std::endl;
+            << "unexpected exception while async task execution:\n"
+            << e << std::endl;
         std::abort();
       }
     }
@@ -66,8 +66,8 @@ class ContextFixture : public ::testing::TestWithParam<Context::Kind> {
         task(param_);
       } catch (const Exception& e) {
         std::cerr
-            << "unexpected exception while sync task execution: " << e.what()
-            << std::endl;
+            << "unexpected exception while sync task execution:\n"
+            << e << std::endl;
         std::abort();
       }
     }

iface/CMakeLists.txt

@@ -6,10 +6,12 @@ target_link_libraries(nf7_iface
 )
 target_sources(nf7_iface
   PRIVATE
+    common/exception.cc
     version.cc
   PUBLIC
     common/dealer.hh
     common/container.hh
+    common/exception.hh
     common/future.hh
     common/observer.hh
     common/task.hh

iface/common/exception.cc

@@ -0,0 +1,28 @@
+// No copyright
+#include "iface/common/exception.hh"
+
+namespace nf7 {
+
+std::ostream& operator<<(std::ostream& st, const Exception& e) {
+  auto idx = uint32_t {0};
+  auto ptr = &e;
+  while (true) {
+    const auto& loc = ptr->location();
+    st << idx << ": " << ptr->what() << "\n";
+    st << "    " << loc.file_name() << ":" << loc.line() << "\n";
+    st << "    " << loc.function_name() << "\n";
+    try {
+      ptr->RethrowNestedIf();
+      break;
+    } catch (const Exception& e2) {
+      ptr = &e2;
+      ++idx;
+    } catch (const std::exception& e2) {
+      st << idx << ": " << e2.what() << "\n";
+      break;
+    }
+  }
+  return st;
+}
+
+}  // namespace nf7

iface/common/exception.hh

@@ -2,6 +2,7 @@
 #pragma once
 
 #include <exception>
+#include <ostream>
 #include <source_location>
 
 namespace nf7 {
@@ -14,6 +15,12 @@ class Exception : public std::exception, std::nested_exception {
       std::source_location location = std::source_location::current()) :
       what_(what), location_(location) { }
 
+  void RethrowNestedIf() const {
+    if (auto ptr = nested_ptr()) {
+      std::rethrow_exception(ptr);
+    }
+  }
+
   const char* what() const noexcept override { return what_; }
   const std::source_location& location() const noexcept { return location_; }
 
@@ -22,4 +29,6 @@ class Exception : public std::exception, std::nested_exception {
   std::source_location location_;
 };
 
+std::ostream& operator<<(std::ostream&, const Exception& e);
+
 }  // namespace nf7