From b2c007b87dcd5db5d59447de2081777aea66f35f Mon Sep 17 00:00:00 2001 From: Jonathan Wakely Date: Tue, 12 Apr 2022 17:17:20 +0100 Subject: [PATCH] libstdc++: shrink-to-fit in std::basic_stacktrace::current(skip, max) If a large stacktrace is reduced to a max depth that is less than half the capacity it will now be reallocated to remove the unused capacity. libstdc++-v3/ChangeLog: * include/std/stacktrace (basic_stacktrace::current): Reallocate a smaller container if the unused capacity is larger than the used size. --- libstdc++-v3/include/std/stacktrace | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/libstdc++-v3/include/std/stacktrace b/libstdc++-v3/include/std/stacktrace index 382d900a822..98ce9231150 100644 --- a/libstdc++-v3/include/std/stacktrace +++ b/libstdc++-v3/include/std/stacktrace @@ -289,7 +289,20 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION if (__err < 0) __ret._M_clear(); else if (__ret.size() > __max_depth) - __ret._M_impl._M_resize(__max_depth, __ret._M_alloc); + { + __ret._M_impl._M_resize(__max_depth, __ret._M_alloc); + + if (__ret._M_impl._M_capacity / 2 >= __max_depth) + { + // shrink to fit + _Impl __tmp = __ret._M_impl._M_clone(__ret._M_alloc); + if (__tmp._M_capacity) + { + __ret._M_clear(); + __ret._M_impl = __tmp; + } + } + } } return __ret; }