[k2] add backtrace in exception (#1336)

Author: astrophysik

runtime-light/state/instance-state.cpp

@@ -79,7 +79,7 @@ void InstanceState::init_script_execution() noexcept {
             [](kphp::coro::task<> script_task) noexcept -> kphp::coro::task<> {
               co_await script_task;
               if (auto exception{std::move(ForkInstanceState::get().current_info().get().thrown_exception)}; !exception.is_null()) [[unlikely]] {
-                kphp::log::error("unhandled exception '{}' at {}:{}", exception.get_class(), exception.get()->$file.c_str(), exception.get()->$line);
+                kphp::log::error("unhandled exception {}", std::move(exception));
               }
             },
             std::move(script_task));

runtime-light/stdlib/diagnostics/error-handling-functions.h

@@ -6,25 +6,32 @@
 
 #include <array>
 #include <cstddef>
+#include <cstdint>
 #include <format>
+#include <span>
+#include <utility>
 
 #include "runtime-common/core/runtime-core.h"
 #include "runtime-light/k2-platform/k2-api.h"
 #include "runtime-light/stdlib/diagnostics/backtrace.h"
 #include "runtime-light/utils/logs.h"
 
 namespace error_handling_impl_ {
+inline constexpr std::string_view FUNCTION_KEY = "function";
+inline constexpr std::string_view FILENAME_KEY = "file";
+inline constexpr std::string_view LINE_KEY = "line";
 
 inline array<array<string>> format_backtrace_symbols(std::span<void* const> backtrace) noexcept {
+
   auto resolved_backtrace{kphp::diagnostic::backtrace_symbols(backtrace)};
   if (resolved_backtrace.empty()) {
     return {};
   }
 
   array<array<string>> backtrace_symbols{array_size{static_cast<int64_t>(backtrace.size()), true}};
-  const string function_key{"function"};
-  const string filename_key{"file"};
-  const string line_key{"line"};
+  const string function_key{FUNCTION_KEY.data(), FUNCTION_KEY.size()};
+  const string filename_key{FILENAME_KEY.data(), FILENAME_KEY.size()};
+  const string line_key{LINE_KEY.data(), LINE_KEY.size()};
 
   for (const k2::SymbolInfo& symbol_info : resolved_backtrace) {
     array<string> frame_info{array_size{3, false}};
@@ -47,11 +54,12 @@ inline array<array<string>> format_backtrace_addresses(std::span<void* const> ba
   }
 
   array<array<string>> backtrace_addresses{array_size{static_cast<int64_t>(backtrace.size()), true}};
-  const string function_key{"function"};
+  const string function_key{FUNCTION_KEY.data(), FUNCTION_KEY.size()};
 
   for (const auto& address : resolved_backtrace) {
     std::array<char, LOG_BUFFER_SIZE> log_buffer{};
-    const auto [_, recorded]{std::format_to_n(log_buffer.data(), log_buffer.size() - 1, "{}", address)};
+    const auto [out, recorded]{std::format_to_n(log_buffer.data(), log_buffer.size() - 1, "{}", address)};
+    *out = '\0';
     array<string> frame_info{array_size{1, false}};
     frame_info.set_value(function_key, string{log_buffer.data(), static_cast<string::size_type>(recorded)});
 

runtime-light/stdlib/diagnostics/exception-types.h

@@ -4,15 +4,21 @@
 
 #pragma once
 
+#include <array>
 #include <cstddef>
 #include <cstdint>
 #include <cstring>
+#include <format>
+#include <span>
 #include <string_view>
+#include <utility>
 
 #include "common/algorithms/hashes.h"
 #include "runtime-common/core/class-instance/refcountable-php-classes.h"
 #include "runtime-common/core/runtime-core.h"
 #include "runtime-common/stdlib/visitors/memory-visitors.h"
+#include "runtime-light/stdlib/diagnostics/backtrace.h"
+#include "runtime-light/stdlib/diagnostics/error-handling-functions.h"
 #include "runtime-light/stdlib/visitors/array-visitors.h"
 #include "runtime-light/utils/logs.h"
 
@@ -71,12 +77,24 @@ struct C$Throwable : public refcountable_polymorphic_php_classes_virt<> {
 
 using Throwable = class_instance<C$Throwable>;
 
+template<>
+struct std::formatter<Throwable> {
+  template<typename ParseContext>
+  constexpr auto parse(ParseContext& ctx) const noexcept {
+    return ctx.begin();
+  }
+
+  template<typename FmtContext>
+  auto format(const Throwable& e, FmtContext& ctx) const noexcept {
+    format_to(ctx.out(), "'{}' at {}:{}", e->$message.c_str(), e->$file.c_str(), e->$line);
+    return ctx.out();
+  }
+};
+
 // ================================================================================================
 
 namespace exception_impl_ {
 
-inline constexpr int32_t backtrace_size_limit = 64;
-
 inline string exception_trace_as_string(const Throwable& e) noexcept {
   auto& static_SB{RuntimeContext::get().static_SB.clean()};
   for (int64_t i = 0; i < e->trace.count(); ++i) {
@@ -89,7 +107,7 @@ inline string exception_trace_as_string(const Throwable& e) noexcept {
 inline void exception_initialize(const Throwable& e, const string& message, int64_t code) noexcept {
   e->$message = message;
   e->$code = code;
-  kphp::log::warning("exception backtrace is not yet supported"); // TODO
+  e->trace = f$debug_backtrace();
 }
 
 } // namespace exception_impl_