Better module backtraces for panics and whatnot (#577)

# Description of Changes


![image](https://github.com/clockworklabs/SpacetimeDB/assets/33094578/9c6356af-9b34-462a-8441-8bd859a73b86)

If these symbols aren't in the stack, it does no processing

# Expected complexity level and risk

1 - it's pretty self-contained, and backwards-compatible with the
existing logs data format

---------

Co-authored-by: Tyler Cloutier <cloutiertyler@users.noreply.github.com>
Co-authored-by: clockwork-labs-bot <clockwork-labs-bot@users.noreply.github.com>

Author: 3 people

crates/bindings-cpp/include/spacetimedb/internal/runtime_registration.h

@@ -1,9 +1,12 @@
 #ifndef SPACETIMEDB_RUNTIME_REGISTRATION_H
 #define SPACETIMEDB_RUNTIME_REGISTRATION_H
 
+#include <atomic>
 #include <functional>
 #include <optional>
 #include <string>
+#include <type_traits>
+#include <utility>
 #include <vector>
 #include "../abi/opaque_types.h"
 #include "autogen/Lifecycle.g.h"
@@ -33,6 +36,18 @@ std::vector<uint8_t> ConsumeBytes(BytesSource source);
 void SetMultiplePrimaryKeyError(const std::string& table_name);
 void SetConstraintRegistrationError(const std::string& code, const std::string& details);
 
+template <typename F>
+__attribute__((noinline)) decltype(auto) __spacetimedb_begin_short_backtrace(F&& f) {
+    if constexpr (std::is_void_v<std::invoke_result_t<F>>) {
+        std::forward<F>(f)();
+        std::atomic_signal_fence(std::memory_order_seq_cst);
+    } else {
+        decltype(auto) result = std::forward<F>(f)();
+        std::atomic_signal_fence(std::memory_order_seq_cst);
+        return result;
+    }
+}
+
 } // namespace Internal
 } // namespace SpacetimeDB
 

crates/bindings-cpp/include/spacetimedb/internal/v10_builder.h

@@ -337,7 +337,9 @@ class V10Builder {
         std::function<void(ReducerContext&, BytesSource)> handler;
         if constexpr (traits::arity == 1) {
             handler = [func](ReducerContext& ctx, BytesSource) {
-                auto result = func(ctx);
+                auto result = __spacetimedb_begin_short_backtrace([&] {
+                    return func(ctx);
+                });
                 if (result.is_err()) {
                     ::SpacetimeDB::fail_reducer(result.error());
                 }
@@ -349,7 +351,9 @@ class V10Builder {
                     bsatn::Reader reader(bytes.data(), bytes.size());
                     auto args = std::make_tuple(bsatn::deserialize<typename traits::template arg_t<Js + 1>>(reader)...);
                     std::apply([&ctx_inner, fn](auto&&... unpacked) {
-                        auto result = fn(ctx_inner, std::forward<decltype(unpacked)>(unpacked)...);
+                        auto result = __spacetimedb_begin_short_backtrace([&] {
+                            return fn(ctx_inner, std::forward<decltype(unpacked)>(unpacked)...);
+                        });
                         if (result.is_err()) {
                             ::SpacetimeDB::fail_reducer(result.error());
                         }
@@ -406,7 +410,9 @@ class V10Builder {
         std::function<void(ReducerContext&, BytesSource)> handler;
         if constexpr (traits::arity == 1) {
             handler = [func](ReducerContext& ctx, BytesSource) {
-                auto result = func(ctx);
+                auto result = __spacetimedb_begin_short_backtrace([&] {
+                    return func(ctx);
+                });
                 if (result.is_err()) {
                     ::SpacetimeDB::fail_reducer(result.error());
                 }
@@ -418,7 +424,9 @@ class V10Builder {
                     bsatn::Reader reader(bytes.data(), bytes.size());
                     auto args = std::make_tuple(bsatn::deserialize<typename traits::template arg_t<Js + 1>>(reader)...);
                     std::apply([&ctx_inner, fn](auto&&... unpacked) {
-                        auto result = fn(ctx_inner, std::forward<decltype(unpacked)>(unpacked)...);
+                        auto result = __spacetimedb_begin_short_backtrace([&] {
+                            return fn(ctx_inner, std::forward<decltype(unpacked)>(unpacked)...);
+                        });
                         if (result.is_err()) {
                             ::SpacetimeDB::fail_reducer(result.error());
                         }
@@ -461,7 +469,9 @@ class V10Builder {
             std::function<std::vector<uint8_t>(ViewContext&, BytesSource)> handler =
                 [func](ViewContext& ctx, BytesSource args_source) -> std::vector<uint8_t> {
                     (void)args_source;
-                    auto result = func(ctx);
+                    auto result = __spacetimedb_begin_short_backtrace([&] {
+                        return func(ctx);
+                    });
                     auto result_vec = view_result_to_vec(std::move(result));
                     IterBuf buf = IterBuf::take();
                     {
@@ -475,7 +485,9 @@ class V10Builder {
             std::function<std::vector<uint8_t>(AnonymousViewContext&, BytesSource)> handler =
                 [func](AnonymousViewContext& ctx, BytesSource args_source) -> std::vector<uint8_t> {
                     (void)args_source;
-                    auto result = func(ctx);
+                    auto result = __spacetimedb_begin_short_backtrace([&] {
+                        return func(ctx);
+                    });
                     auto result_vec = view_result_to_vec(std::move(result));
                     IterBuf buf = IterBuf::take();
                     {
@@ -525,7 +537,9 @@ class V10Builder {
         std::function<std::vector<uint8_t>(ProcedureContext&, BytesSource)> handler;
         if constexpr (traits::arity == 1) {
             handler = [func](ProcedureContext& ctx, BytesSource) -> std::vector<uint8_t> {
-                auto result = func(ctx);
+                auto result = __spacetimedb_begin_short_backtrace([&] {
+                    return func(ctx);
+                });
                 IterBuf buf = IterBuf::take();
                 {
                     bsatn::Writer writer(buf.get());
@@ -539,9 +553,11 @@ class V10Builder {
                 return []<std::size_t... Js>(std::index_sequence<Js...>, Func fn, ProcedureContext& ctx_inner, const std::vector<uint8_t>& bytes) -> std::vector<uint8_t> {
                     bsatn::Reader reader(bytes.data(), bytes.size());
                     auto args = std::make_tuple(bsatn::deserialize<typename traits::template arg_t<Js + 1>>(reader)...);
-                    auto result = std::apply([&ctx_inner, fn](auto&&... unpacked) {
-                        return fn(ctx_inner, std::forward<decltype(unpacked)>(unpacked)...);
-                    }, args);
+                    auto result = __spacetimedb_begin_short_backtrace([&] {
+                        return std::apply([&ctx_inner, fn](auto&&... unpacked) {
+                            return fn(ctx_inner, std::forward<decltype(unpacked)>(unpacked)...);
+                        }, args);
+                    });
                     IterBuf buf = IterBuf::take();
                     {
                         bsatn::Writer writer(buf.get());