From 854d3dcaf84c900482e8b94d2bb475b923fb84d2 Mon Sep 17 00:00:00 2001
From: Christian Menard <christian@xronos.com>
Date: Wed, 17 Jul 2024 13:50:13 +0200
Subject: [PATCH] Portable backtrace mechanism

---
 CMakeLists.txt                   |  5 +++-
 include/reactor-cpp/assert.hh    | 47 +++++++++++++++++++-------------
 include/reactor-cpp/config.hh.in |  3 ++
 lib/CMakeLists.txt               |  5 ++++
 lib/assert.cc                    |  4 +--
 5 files changed, 41 insertions(+), 23 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0b908131..24e5bbed 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -30,7 +30,10 @@ if (NOT DEFINED LF_REACTOR_CPP_SUFFIX)
   endif()
 endif()
 
-find_package (Threads)
+find_package(Threads)
+
+find_package(Backtrace)
+set(REACTOR_CPP_USE_BACKTRACE ${Backtrace_FOUND})
 
 set(DEFAULT_BUILD_TYPE "Release")
 if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
diff --git a/include/reactor-cpp/assert.hh b/include/reactor-cpp/assert.hh
index ffffff31..8483e8de 100644
--- a/include/reactor-cpp/assert.hh
+++ b/include/reactor-cpp/assert.hh
@@ -17,11 +17,6 @@
 #include <stdexcept>
 #include <string>
 
-#ifdef __linux__
-#include <execinfo.h>
-#include <unistd.h>
-#endif
-
 #ifdef REACTOR_CPP_VALIDATE
 constexpr bool runtime_validation = true;
 #else
@@ -37,6 +32,33 @@ constexpr bool runtime_assertion = true;
 // NOLINTNEXTLINE(cppcoreguidelines-macro-usage)
 #define reactor_assert(x) assert(x)
 
+#ifdef REACTOR_CPP_USE_BACKTRACE
+
+// NOLINTNEXTLINE
+#include REACTOR_CPP_BACKTRACE_HEADER
+#include <array>
+#include <iostream>
+
+namespace reactor {
+
+constexpr std::size_t MAX_TRACE_SIZE{16};
+
+inline void print_backtrace() {
+  std::array<void*, MAX_TRACE_SIZE> trace{nullptr};
+  int size = backtrace(trace.data(), MAX_TRACE_SIZE);
+  char** messages = backtrace_symbols(trace.data(), size);
+  for (int i{0}; i < size; i++) {
+    std::cerr << "[backtrace] " << messages[i] << '\n'; // NOLINT
+  }
+}
+
+} // namespace reactor
+#else
+namespace reactor {
+inline void print_backtrace() {}
+} // namespace reactor
+#endif // REACTOR_CPP_BACKTRACE_SUPPORT
+
 namespace reactor {
 
 class ValidationError : public std::runtime_error {
@@ -48,23 +70,10 @@ public:
       : std::runtime_error(build_message(msg)) {}
 };
 
-#ifdef __linux__
-constexpr std::size_t MAX_STACK_SIZE{10};
-
-inline void print_debug_backtrace() {
-  void* array[10]; // NOLINT
-  // get void*'s for all entries on the stack
-  int size = backtrace((void**)array, MAX_STACK_SIZE);
-  backtrace_symbols_fd((void**)array, size, STDERR_FILENO);
-}
-#endif
-
 constexpr inline void validate([[maybe_unused]] bool condition, [[maybe_unused]] const std::string_view message) {
   if constexpr (runtime_validation) { // NOLINT
     if (!condition) {
-#ifdef __linux__
-      print_debug_backtrace();
-#endif
+      print_backtrace();
       throw ValidationError(message);
     }
   }
diff --git a/include/reactor-cpp/config.hh.in b/include/reactor-cpp/config.hh.in
index 94b9d2ea..472eff23 100644
--- a/include/reactor-cpp/config.hh.in
+++ b/include/reactor-cpp/config.hh.in
@@ -10,4 +10,7 @@
 // NOLINTNEXTLINE
 #cmakedefine REACTOR_CPP_LOG_LEVEL @REACTOR_CPP_LOG_LEVEL@
 
+#cmakedefine REACTOR_CPP_USE_BACKTRACE
+#define REACTOR_CPP_BACKTRACE_HEADER <@Backtrace_HEADER@>
+
 #endif
diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index fd47bcfb..43265b9f 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -36,6 +36,11 @@ else()
   target_compile_options(${LIB_TARGET} PRIVATE -Wall -Wextra -pedantic -Werror)
 endif()
 
+if(${Backtrace_FOUND})
+  target_include_directories(${LIB_TARGET} PRIVATE ${Backtrace_INCLUDE_DIRS})
+  target_link_libraries(${LIB_TARGET} ${Backtrace_LIBRARY})
+endif()
+
 target_link_libraries(${LIB_TARGET} ${CMAKE_THREAD_LIBS_INIT})
 if(REACTOR_CPP_TRACE)
   target_link_libraries(${LIB_TARGET} LTTng::UST)
diff --git a/lib/assert.cc b/lib/assert.cc
index 5e6e9584..22403ae2 100644
--- a/lib/assert.cc
+++ b/lib/assert.cc
@@ -33,9 +33,7 @@ void assert_phase([[maybe_unused]] const ReactorElement* ptr, [[maybe_unused]] P
         }
         return "Unknown Phase: Value: " + std::to_string(extract_value(phase));
       };
-#ifdef __linux__
-      print_debug_backtrace();
-#endif
+      print_backtrace();
 
       // C++20 std::format
       throw ValidationError("Expected Phase: " + enum_value_to_name(phase) +