From 5571f56fe0ced1805110e06ac38d4fc8105c45cc Mon Sep 17 00:00:00 2001
From: Romain Geissler <romain.geissler@amadeus.com>
Date: Mon, 8 Dec 2025 16:03:24 +0000
Subject: [PATCH] Enable stack traces from exception on ARM by default if using
 libstdc++.

We know the implementation works on any architecture if libstdc++ is used
(leaks are with libc++). So enable it by default in that case, even if
not using x86.
---
 CMakeLists.txt           |  4 +++-
 build/Jamfile.v2         | 10 ++++++++--
 build/uses_libstdc++.cpp | 15 +++++++++++++++
 src/from_exception.cpp   |  8 ++++++++
 4 files changed, 34 insertions(+), 3 deletions(-)
 create mode 100644 build/uses_libstdc++.cpp

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1b95379..c50804f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -71,8 +71,10 @@ endif()
 stacktrace_check(BOOST_STACKTRACE_HAS_WINDBG has_windbg.cpp "" "dbgeng;ole32" "")
 stacktrace_check(BOOST_STACKTRACE_HAS_WINDBG_CACHED has_windbg_cached.cpp "${CMAKE_CURRENT_SOURCE_DIR}/../config/include" "dbgeng;ole32" "")
 
+stacktrace_check(BOOST_STACKTRACE_USES_LIBSTDCPP uses_libstdc++.cpp "" "" "")
+
 set(_default_from_exception ON)
-if (NOT CMAKE_SYSTEM_PROCESSOR MATCHES "x86_64|AMD64|amd64|i386|i686|x86")
+if ((NOT CMAKE_SYSTEM_PROCESSOR MATCHES "x86_64|AMD64|amd64|i386|i686|x86") AND (NOT BOOST_STACKTRACE_USES_LIBSTDCPP))
   set(_default_from_exception OFF)
 endif()
 
diff --git a/build/Jamfile.v2 b/build/Jamfile.v2
index 9a294bf..42c3930 100644
--- a/build/Jamfile.v2
+++ b/build/Jamfile.v2
@@ -64,6 +64,9 @@ explicit WinDbg ;
 mp-run-simple has_windbg_cached.cpp : : : <library>Dbgeng <library>ole32 : WinDbgCached ;
 explicit WinDbgCached ;
 
+mp-run-simple uses_libstdc++.cpp : : : : UsesLibStdCpp ;
+explicit UsesLibStdCpp ;
+
 rule build-stacktrace-noop ( props * )
 {
     local enabled = [ property.select <boost.stacktrace.noop> : $(props) ] ;
@@ -252,8 +255,11 @@ rule build-stacktrace-from-exception ( props * )
     local arch = [ property.select <architecture> : $(props) ] ;
     if $(arch) && ( $(arch:G=) != x86 )
     {
-        configure.log-library-search-result "boost.stacktrace.from_exception" : "no" ;
-        return <build>no ;
+        if ! [ configure.builds UsesLibStdCpp : $(props) : "boost.stacktrace.from_exception" ]
+        {
+            configure.log-library-search-result "boost.stacktrace.from_exception" : "no" ;
+            return <build>no ;
+        }
     }
     configure.log-library-search-result "boost.stacktrace.from_exception" : "yes" ;
 }
diff --git a/build/uses_libstdc++.cpp b/build/uses_libstdc++.cpp
new file mode 100644
index 0000000..9aae4b3
--- /dev/null
+++ b/build/uses_libstdc++.cpp
@@ -0,0 +1,15 @@
+// Copyright Romain Geissler, 2025.
+//
+// Distributed under the Boost Software License, Version 1.0. (See
+// accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+
+#include <cstdlib>
+
+int main() {
+#ifdef __GLIBCXX__
+    return 0;
+#else
+#error "The C++ runtime library isn't libstdc++"
+#endif
+}
diff --git a/src/from_exception.cpp b/src/from_exception.cpp
index 366ba28..3e36def 100644
--- a/src/from_exception.cpp
+++ b/src/from_exception.cpp
@@ -164,6 +164,12 @@ BOOST_SYMBOL_EXPORT void assert_no_pending_traces() noexcept {
 #include <mutex>
 #include <unordered_map>
 
+// If we use libstdc++, we know the current implementation works and doesn't leak.
+// It's not the case of libc++ where we know there might be leaks and thus we try
+// to ensure the user is aware about it and only build this when
+// BOOST_STACKTRACE_LIBCXX_RUNTIME_MAY_CAUSE_MEMORY_LEAK is defined.
+#ifndef __GLIBCXX__
+
 #ifndef BOOST_STACKTRACE_LIBCXX_RUNTIME_MAY_CAUSE_MEMORY_LEAK
 
 #ifdef BOOST_HAS_THREADS
@@ -185,6 +191,8 @@ BOOST_SYMBOL_EXPORT void assert_no_pending_traces() noexcept {
 
 #endif
 
+#endif
+
 namespace {
 
 constexpr std::size_t kStacktraceDumpSize = 4096;