Add C++23 stacktrace

Author: elsteveogrande

libcxx/CMakeLists.txt

@@ -131,6 +131,11 @@ option(LIBCXX_ENABLE_VENDOR_AVAILABILITY_ANNOTATIONS
    the shared library they shipped should turn this on and see `include/__configuration/availability.h`
    for more details." OFF)
 
+option(LIBCXX_STACKTRACE_ALLOW_TOOLS_AT_RUNTIME
+   "For C++23 <stacktrace>: whether to allow invocation of `addr2line`, `llvm-addr2line`, or `atos`
+   at runtime (if it's available in `PATH`) to resolve call-chain addresses in the stacktrace
+   into source locations, if other methods are not available." ON)
+
 if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
   set(LIBCXX_DEFAULT_TEST_CONFIG "llvm-libc++-shared-gcc.cfg.in")
 elseif(MINGW)
@@ -750,6 +755,7 @@ config_define(${LIBCXX_ENABLE_UNICODE} _LIBCPP_HAS_UNICODE)
 config_define(${LIBCXX_ENABLE_WIDE_CHARACTERS} _LIBCPP_HAS_WIDE_CHARACTERS)
 config_define(${LIBCXX_ENABLE_TIME_ZONE_DATABASE} _LIBCPP_HAS_TIME_ZONE_DATABASE)
 config_define(${LIBCXX_ENABLE_VENDOR_AVAILABILITY_ANNOTATIONS} _LIBCPP_HAS_VENDOR_AVAILABILITY_ANNOTATIONS)
+config_define(${LIBCXX_STACKTRACE_ALLOW_TOOLS_AT_RUNTIME} _LIBCPP_STACKTRACE_ALLOW_TOOLS_AT_RUNTIME)
 
 # TODO: Remove in LLVM 21. We're leaving an error to make this fail explicitly.
 if (LIBCXX_ENABLE_ASSERTIONS)

libcxx/docs/FeatureTestMacroTable.rst

@@ -396,7 +396,7 @@ Status
     ---------------------------------------------------------- -----------------
     ``__cpp_lib_spanstream``                                   *unimplemented*
     ---------------------------------------------------------- -----------------
-    ``__cpp_lib_stacktrace``                                   *unimplemented*
+    ``__cpp_lib_stacktrace``                                   ``202011L``
     ---------------------------------------------------------- -----------------
     ``__cpp_lib_stdatomic_h``                                  ``202011L``
     ---------------------------------------------------------- -----------------

libcxx/docs/ReleaseNotes/21.rst

@@ -53,6 +53,8 @@ Implemented Papers
 - P2711R1: Making multi-param constructors of ``views`` ``explicit`` (`Github <https://github.com/llvm/llvm-project/issues/105252>`__)
 - P2770R0: Stashing stashing ``iterators`` for proper flattening (`Github <https://github.com/llvm/llvm-project/issues/105250>`__)
 - P2655R3: ``common_reference_t`` of ``reference_wrapper`` Should Be a Reference Type (`Github <https://github.com/llvm/llvm-project/issues/105260>`__)
+- P0881R7: A Proposal to add stacktrace library (`Github <https://github.com/llvm/llvm-project/issues/105131>`__)
+- P2301R1: Add a `pmr` alias for `std::stacktrace` (`Github <https://github.com/llvm/llvm-project/issues/105167>`__)
 
 Improvements and New Features
 -----------------------------

libcxx/docs/Status/Cxx23Issues.csv

@@ -189,7 +189,7 @@
 "`LWG3028 <https://wg21.link/LWG3028>`__","Container requirements tables should distinguish ``const`` and non-``const`` variables","2022-11 (Kona)","","",""
 "`LWG3118 <https://wg21.link/LWG3118>`__","``fpos`` equality comparison unspecified","2022-11 (Kona)","","",""
 "`LWG3177 <https://wg21.link/LWG3177>`__","Limit permission to specialize variable templates to program-defined types","2022-11 (Kona)","|Nothing To Do|","",""
-"`LWG3515 <https://wg21.link/LWG3515>`__","§[stacktrace.basic.nonmem]: ``operator<<`` should be less templatized","2022-11 (Kona)","","",""
+"`LWG3515 <https://wg21.link/LWG3515>`__","§[stacktrace.basic.nonmem]: ``operator<<`` should be less templatized","2022-11 (Kona)","|Nothing To Do|","",""
 "`LWG3545 <https://wg21.link/LWG3545>`__","``std::pointer_traits`` should be SFINAE-friendly","2022-11 (Kona)","|Complete|","18",""
 "`LWG3569 <https://wg21.link/LWG3569>`__","``join_view`` fails to support ranges of ranges with non-default_initializable iterators","2022-11 (Kona)","","",""
 "`LWG3594 <https://wg21.link/LWG3594>`__","``inout_ptr`` — inconsistent ``release()`` in destructor","2022-11 (Kona)","|Complete|","19",""

libcxx/docs/Status/Cxx23Papers.csv

@@ -1,5 +1,5 @@
 "Paper #","Paper Name","Meeting","Status","First released version","Notes"
-"`P0881R7 <https://wg21.link/P0881R7>`__","A Proposal to add stacktrace library","2020-11 (Virtual)","","",""
+"`P0881R7 <https://wg21.link/P0881R7>`__","A Proposal to add stacktrace library","2020-11 (Virtual)","|Complete|","21",""
 "`P0943R6 <https://wg21.link/P0943R6>`__","Support C atomics in C++","2020-11 (Virtual)","|Complete|","15",""
 "`P1048R1 <https://wg21.link/P1048R1>`__","A proposal for a type trait to detect scoped enumerations","2020-11 (Virtual)","|Complete|","12",""
 "`P1679R3 <https://wg21.link/P1679R3>`__","string contains function","2020-11 (Virtual)","|Complete|","12",""
@@ -32,7 +32,7 @@
 "`P1675R2 <https://wg21.link/P1675R2>`__","``rethrow_exception`` must be allowed to copy","2021-10 (Virtual)","|Nothing To Do|","",""
 "`P2077R3 <https://wg21.link/P2077R3>`__","Heterogeneous erasure overloads for associative containers","2021-10 (Virtual)","","",""
 "`P2251R1 <https://wg21.link/P2251R1>`__","Require ``span`` & ``basic_string_view`` to be Trivially Copyable","2021-10 (Virtual)","|Complete|","14",""
-"`P2301R1 <https://wg21.link/P2301R1>`__","Add a ``pmr`` alias for ``std::stacktrace``","2021-10 (Virtual)","","",""
+"`P2301R1 <https://wg21.link/P2301R1>`__","Add a ``pmr`` alias for ``std::stacktrace``","2021-10 (Virtual)","|Complete|","21",""
 "`P2321R2 <https://wg21.link/P2321R2>`__","``zip``","2021-10 (Virtual)","|In Progress|","",""
 "`P2340R1 <https://wg21.link/P2340R1>`__","Clarifying the status of the 'C headers'","2021-10 (Virtual)","|Nothing To Do|","",""
 "`P2393R1 <https://wg21.link/P2393R1>`__","Cleaning up ``integer``-class types","2021-10 (Virtual)","","",""
@@ -110,7 +110,7 @@
 "`P2713R1 <https://wg21.link/P2713R1>`__","Escaping improvements in ``std::format``","2023-02 (Issaquah)","|Complete|","19",""
 "`P2675R1 <https://wg21.link/P2675R1>`__","``format``'s width estimation is too approximate and not forward compatible","2023-02 (Issaquah)","|Complete|","17",""
 "`P2572R1 <https://wg21.link/P2572R1>`__","``std::format`` fill character allowances","2023-02 (Issaquah)","|Complete|","17",""
-"`P2693R1 <https://wg21.link/P2693R1>`__","Formatting ``thread::id`` and ``stacktrace``","2023-02 (Issaquah)","|Partial|","","The formatter for ``stacktrace`` is not implemented, since ``stacktrace`` is not implemented yet"
+"`P2693R1 <https://wg21.link/P2693R1>`__","Formatting ``thread::id`` and ``stacktrace``","2023-02 (Issaquah)","|Partial|","","The formatter for ``stacktrace`` is not implemented yet"
 "`P2679R2 <https://wg21.link/P2679R2>`__","Fixing ``std::start_lifetime_as`` for arrays","2023-02 (Issaquah)","","",""
 "`P2674R1 <https://wg21.link/P2674R1>`__","A trait for implicit lifetime types","2023-02 (Issaquah)","|Complete|","20",""
 "`P2655R3 <https://wg21.link/P2655R3>`__","``common_reference_t`` of ``reference_wrapper`` Should Be a Reference Type","2023-02 (Issaquah)","|Complete|","21","The paper is implemented as a DR to C++20"

libcxx/docs/VendorDocumentation.rst

@@ -185,6 +185,14 @@ General purpose options
    ship the IANA time zone database. When time zones are not supported,
    time zone support in <chrono> will be disabled.
 
+.. option:: LIBCXX_STACKTRACE_ALLOW_TOOLS_AT_RUNTIME:BOOL
+
+   **Default**: ``ON``
+
+   For C++23 <stacktrace>: whether to allow invocation of ``addr2line``, ``llvm-addr2line``, or ``atos``
+   at runtime (if it's available in ``PATH``) to resolve call-chain addresses in the stacktrace
+   into source locations, if other methods are not available.
+
 .. option:: LIBCXX_INSTALL_LIBRARY_DIR:PATH
 
   **Default**: ``lib${LIBCXX_LIBDIR_SUFFIX}``

libcxx/include/CMakeLists.txt

@@ -739,6 +739,12 @@ set(files
   __ranges/views.h
   __ranges/zip_view.h
   __split_buffer
+  __stacktrace/base.h
+  __stacktrace/basic.h
+  __stacktrace/entry.h
+  __stacktrace/hash.h
+  __stacktrace/nonmem.h
+  __stacktrace/to_string.h
   __std_mbstate_t.h
   __stop_token/atomic_unique_lock.h
   __stop_token/intrusive_list_view.h
@@ -1058,6 +1064,7 @@ set(files
   span
   sstream
   stack
+  stacktrace
   stdatomic.h
   stdbool.h
   stddef.h

libcxx/include/__config

@@ -924,6 +924,33 @@ typedef __char32_t char32_t;
 #    define _LIBCPP_NOINLINE
 #  endif
 
+// Some functions, e.g. std::stacktrace::current, need to avoid being
+// tail-called by (and tail-calling other) functions, for proper enumeration of
+// call-stack frames.
+// clang-format off
+
+// Disables tail-call optimization for "outbound" calls
+// performed in the function annotated with this attribute.
+#  if __has_cpp_attribute(_Clang::__disable_tail_calls__)
+#    define _LIBCPP_NO_TAIL_CALLS_OUT [[_Clang::__disable_tail_calls__]]
+#  elif __has_cpp_attribute(__gnu__::__optimize__)
+#    define _LIBCPP_NO_TAIL_CALLS_OUT [[__gnu__::__optimize__("no-optimize-sibling-calls")]]
+#  else
+#    define _LIBCPP_NO_TAIL_CALLS_OUT
+#  endif
+
+// Disables tail-call optimization for "inbound" calls -- that is,
+// calls from some other function calling the one having this attribute.
+#  if __has_cpp_attribute(_Clang::__not_tail_called__)
+#    define _LIBCPP_NO_TAIL_CALLS_IN [[_Clang::__not_tail_called__]]
+#  else
+#    define _LIBCPP_NO_TAIL_CALLS_IN
+#  endif
+
+// Disable TCO for calls into, and out from, the annotated function.
+#  define _LIBCPP_NO_TAIL_CALLS _LIBCPP_NO_TAIL_CALLS_IN _LIBCPP_NO_TAIL_CALLS_OUT
+// clang-format on
+
 // We often repeat things just for handling wide characters in the library.
 // When wide characters are disabled, it can be useful to have a quick way of
 // disabling it without having to resort to #if-#endif, which has a larger

libcxx/include/__config_site.in

@@ -33,6 +33,7 @@
 #cmakedefine _LIBCPP_HAS_NO_STD_MODULES
 #cmakedefine01 _LIBCPP_HAS_TIME_ZONE_DATABASE
 #cmakedefine01 _LIBCPP_INSTRUMENTED_WITH_ASAN
+#cmakedefine01 _LIBCPP_STACKTRACE_ALLOW_TOOLS_AT_RUNTIME
 
 // PSTL backends
 #cmakedefine _LIBCPP_PSTL_BACKEND_SERIAL

libcxx/include/__stacktrace/base.h

@@ -0,0 +1,133 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_STACKTRACE_BUILDER
+#define _LIBCPP_STACKTRACE_BUILDER
+
+#include <__config>
+#include <__cstddef/byte.h>
+#include <__cstddef/size_t.h>
+#include <__functional/function.h>
+#include <__fwd/format.h>
+#include <__fwd/ostream.h>
+#include <__memory/allocator.h>
+#include <__memory/allocator_traits.h>
+#include <__new/allocate.h>
+#include <__vector/vector.h>
+#include <cstddef>
+#include <cstdint>
+#include <list>
+#include <optional>
+#include <string>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+class _LIBCPP_EXPORTED_FROM_ABI stacktrace_entry;
+
+namespace __stacktrace {
+
+struct _LIBCPP_HIDE_FROM_ABI alloc final {
+  function<byte*(size_t)> __alloc_bytes_;
+  function<void(byte*, size_t)> __dealloc_bytes_;
+
+  template <class _Allocator>
+  _LIBCPP_HIDE_FROM_ABI alloc(_Allocator __alloc) {
+    using _AT        = allocator_traits<_Allocator>;
+    using _BA        = typename _AT::template rebind_alloc<byte>;
+    auto __ba        = _BA(__alloc);
+    __alloc_bytes_   = [__ba](size_t __sz) mutable { return __ba.allocate(__sz); };
+    __dealloc_bytes_ = [__ba](void* __ptr, size_t __sz) mutable { __ba.deallocate((byte*)__ptr, __sz); };
+  }
+
+  template <typename _Tp>
+  struct _LIBCPP_HIDE_FROM_ABI Alloc {
+    function<byte*(size_t)> __alloc_bytes_;
+    function<void(byte*, size_t)> __dealloc_bytes_;
+
+    Alloc(function<byte*(size_t)> __alloc_bytes, function<void(byte*, size_t)> __dealloc_bytes)
+        : __alloc_bytes_(__alloc_bytes), __dealloc_bytes_(__dealloc_bytes) {}
+
+    template <typename _T2 = _Tp>
+    Alloc(Alloc<_T2> const& __rhs) : Alloc(__rhs.__alloc_bytes_, __rhs.__dealloc_bytes_) {}
+
+    using value_type = _Tp;
+    [[nodiscard]] _Tp* allocate(size_t __sz) { return (_Tp*)__alloc_bytes_(__sz * sizeof(_Tp)); }
+    void deallocate(_Tp* __ptr, size_t __sz) { __dealloc_bytes_((byte*)__ptr, __sz * sizeof(_Tp)); }
+
+    template <typename _A2>
+    bool operator==(_A2 const& __rhs) const {
+      return &__rhs == this;
+    }
+  };
+
+  template <typename _Tp>
+  Alloc<_Tp> _LIBCPP_HIDE_FROM_ABI make_alloc() {
+    return {__alloc_bytes_, __dealloc_bytes_};
+  }
+
+  using str = basic_string<char, char_traits<char>, Alloc<char>>;
+
+  template <typename... _Args>
+  str _LIBCPP_HIDE_FROM_ABI make_str(_Args... __args) {
+    return str(std::forward<_Args>(__args)..., make_alloc<char>());
+  }
+
+  template <typename _Tp>
+  using vec = vector<_Tp, Alloc<_Tp>>;
+
+  template <typename _Tp, typename... _Args>
+  _LIBCPP_HIDE_FROM_ABI vec<_Tp> make_vec(_Args... __args) {
+    return vec(std::forward<_Args>(__args)..., make_alloc<_Tp>());
+  }
+
+  template <typename _Tp>
+  using list = ::std::list<_Tp, Alloc<_Tp>>;
+
+  template <typename _Tp, typename... _Args>
+  _LIBCPP_HIDE_FROM_ABI list<_Tp> make_list(_Args... __args) {
+    return list(std::forward<_Args>(__args)..., make_alloc<_Tp>());
+  }
+};
+
+struct _LIBCPP_HIDE_FROM_ABI entry_base {
+  uintptr_t __addr_actual_{};                   // this address, as observed in this current process
+  uintptr_t __addr_unslid_{};                   // address adjusted for ASLR
+  optional<__stacktrace::alloc::str> __desc_{}; // uses wrapped _Allocator from caller
+  optional<__stacktrace::alloc::str> __file_{}; // uses wrapped _Allocator from caller
+  uint_least32_t __line_{};
+
+  _LIBCPP_HIDE_FROM_ABI stacktrace_entry to_stacktrace_entry() const;
+};
+
+struct _LIBCPP_EXPORTED_FROM_ABI builder final {
+  alloc __alloc_; // wraps the caller-provided allocator
+  alloc::vec<entry_base> __entries_;
+  alloc::str __main_prog_path_;
+
+  template <class _Allocator>
+  explicit _LIBCPP_EXPORTED_FROM_ABI builder(_Allocator __alloc)
+      : __alloc_(__alloc), __entries_(__alloc_.make_vec<entry_base>()), __main_prog_path_(__alloc_.make_str()) {}
+
+  _LIBCPP_NO_TAIL_CALLS _LIBCPP_NOINLINE _LIBCPP_EXPORTED_FROM_ABI void
+  build_stacktrace(size_t __skip, size_t __max_depth);
+};
+
+} // namespace __stacktrace
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP_STACKTRACE_BUILDER