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Re: [boost] Boost Digest, Vol 7279, Issue 2
by Stephen Greenfield 11 Jul '24

11 Jul '24

Richard – > This usually happens because you're compiling with one standard library > (e.g. libc++, the default on clang) while your boost libraries were > compiled with another (e.g. libstdc++, the default on gcc). That makes sense. Does my MacOS program need to be compiled for GCC (IE GNU C++17 / GNU C++20), and then linked with libstdc++ to be compatible with the default build of Boost, or the opposite: build Boost and link with libc++? I saw that there’s a list of toolsets, but in the “getting started with unix variants”, included with the 1_85_0 .zip package, there is no listing for toolset=clang or toolset=clang-darwin. Nor is there any mention of clang on: https://www.boost.org/doc/libs/1_85_0/more/getting_started/unix-variants.ht… Stephen -- ------------------------------ Message: 5 Date: Thu, 11 Jul 2024 09:43:01 +0200 From: Richard Hodges <hodges.r(a)gmail.com> To: boost(a)lists.boost.org Subject: Re: [boost] Updating from 1_71_0 to 1_85_0: "No member named 'memcpy' in namespace 'std::__1'" Message-ID: <CALvx3haD3uRR4sXjjDq5Hrw4XoTq11HMqQyq2D5taJQzH7ys7A(a)mail.gmail.com> Content-Type: text/plain; charset="UTF-8" This usually happens because you're compiling with one standard library (e.g. libc++, the default on clang) while your boost libraries were compiled with another (e.g. libstdc++, the default on gcc). R On Thu, 11 Jul 2024 at 02:21, Stephen Greenfield via Boost < boost(a)lists.boost.org> wrote: > Dear Boost gurus, > > Building on MacOS 12.7.3, Xcode 13.4.1, C++ dialect = C++17. Deployment > target is 10.15. This particular project is x86_64 architecture. I?m only > linking libboost_filesystem.a and libboost_iostreams.a (I show my build > boost build steps at the end). > > When updating from Boost 1_71_0 to 1_85_0, I?m suddenly encountering these > kinds of errors: > > > /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk/usr/include/c++/v1/__functional/hash.h:40:5: > No member named 'memcpy' in namespace 'std::__1'; did you mean simply > 'memcpy'? > > > /Users/stephen/dev/Boost > Libraries/boost_1_85_0/boost/system/detail/append_int.hpp:23:5: No member > named 'snprintf' in namespace 'boost::system::detail'; did you mean simply > 'snprintf'? > > > > > In file included from > /Users/stephen/dev/Screenwriter/ScreenWriterX/ScreenWriterX/Screenwriter > Sources/Text Engine/CThingEdit.cp:22: > > In file included from ../ScreenWriterX/ScreenWriterX/Screenwriter > Sources/Text Engine/CThingEdit.h:61: > > In file included from > /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk/usr/include/c++/v1/string:522: > > In file included from > /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk/usr/include/c++/v1/algorithm:653: > > In file included from > /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk/usr/include/c++/v1/functional:500: > > In file included from > /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk/usr/include/c++/v1/__functional/function.h:20: > > In file included from > /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk/usr/include/c++/v1/__memory/shared_ptr.h:25: > > In file included from > /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk/usr/include/c++/v1/__memory/unique_ptr.h:15: > > /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk/usr/include/c++/v1/__functional/hash.h:40:5: > error: no member named 'memcpy' in namespace 'std::__1'; did you mean > simply 'memcpy'? > > _VSTD::memcpy(&__r, __p, sizeof(__r)); > > ^~~~~~~ > > In file included from <built-in>:1: > > In file included from > /Users/stephen/dev/Screenwriter/ScreenWriterX/ScreenWriterX/Screenwriter > Sources/Screenwriter_Prefix.pch:505: > > In file included from > /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk/usr/include/MacTypes.h:44: > > In file included from > /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk/usr/include/c++/v1/stdbool.h:22: > > /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk/usr/include/c++/v1/__config:858:15: > note: expanded from macro '_VSTD' > > #define _VSTD std::_LIBCPP_ABI_NAMESPACE > > ^ > > In file included from > /Users/stephen/dev/Screenwriter/ScreenWriterX/ScreenWriterX/Screenwriter > Sources/Text Engine/CThingEdit.cp:22: > > In file included from ../ScreenWriterX/ScreenWriterX/Screenwriter > Sources/Text Engine/CThingEdit.h:61: > > In file included from > /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk/usr/include/c++/v1/string:522: > > In file included from > /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk/usr/include/c++/v1/algorithm:652: > > /Users/stephen/dev/Boost > Libraries/boost_1_85_0/boost/compatibility/cpp_c_headers/cstring:22:11: > note: 'memcpy' declared here > > using ::memcpy; > > ^ > ?this is for all sorts of symbols. ALSO: > > > > > Showing All Errors Only > > /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk/usr/include/c++/v1/filesystem:2635:5: > Use of undeclared identifier '_LIBCPP_UNREACHABLE' > > > When including: > > #include <fstream> > > > The libraries were build using: > > ./bootstrap.sh cxxflags="-arch x86_64 -arch arm64" cflags="-arch x86_64 > -arch arm64" linkflags="-arch x86_64 -arch arm64" > > ./b2 toolset=clang-darwin target-os=darwin architecture=arm abi=aapcs > cxxflags="-arch arm64" cflags="-arch arm64" linkflags="-arch arm64" -a > > mkdir -p arm64 && cp stage/lib/*.* arm64 > > ./b2 toolset=clang-darwin target-os=darwin architecture=x86 > cxxflags="-arch x86_64" cflags="-arch x86_64" linkflags="-arch x86_64" > abi=sysv binary-format=mach-o -a > > mkdir x86_64 && cp stage/lib/*.* x86_64 > > The intention was for me to eventually make UNIVERSAL dylibs using lipo ? > but for now, I just want to get my build back to functioning with Boost > 1_85_0. > > NOTE that I?m continuing to use Boost?s Filesystem ? even though I THINK > Xcode?s C++20 might now support std::filesystem. > > I?ve searched all over for the answer ? even consulted ChatGPT ? but > haven?t found a solution. But this seems like something bone-headed I?ve > missed. > > Stephen > > _______________________________________________ > Unsubscribe & other changes: > http://lists.boost.org/mailman/listinfo.cgi/boost > ------------------------------ Subject: Digest Footer _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost ------------------------------ End of Boost Digest, Vol 7279, Issue 2 **************************************

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Updating from 1_71_0 to 1_85_0: "No member named 'memcpy' in namespace 'std::__1'"
by Stephen Greenfield 11 Jul '24

11 Jul '24

Dear Boost gurus, Building on MacOS 12.7.3, Xcode 13.4.1, C++ dialect = C++17. Deployment target is 10.15. This particular project is x86_64 architecture. I’m only linking libboost_filesystem.a and libboost_iostreams.a (I show my build boost build steps at the end). When updating from Boost 1_71_0 to 1_85_0, I’m suddenly encountering these kinds of errors: /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk/usr/include/c++/v1/__functional/hash.h:40:5: No member named 'memcpy' in namespace 'std::__1'; did you mean simply 'memcpy'? /Users/stephen/dev/Boost Libraries/boost_1_85_0/boost/system/detail/append_int.hpp:23:5: No member named 'snprintf' in namespace 'boost::system::detail'; did you mean simply 'snprintf'? In file included from /Users/stephen/dev/Screenwriter/ScreenWriterX/ScreenWriterX/Screenwriter Sources/Text Engine/CThingEdit.cp:22: In file included from ../ScreenWriterX/ScreenWriterX/Screenwriter Sources/Text Engine/CThingEdit.h:61: In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk/usr/include/c++/v1/string:522: In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk/usr/include/c++/v1/algorithm:653: In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk/usr/include/c++/v1/functional:500: In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk/usr/include/c++/v1/__functional/function.h:20: In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk/usr/include/c++/v1/__memory/shared_ptr.h:25: In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk/usr/include/c++/v1/__memory/unique_ptr.h:15: /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk/usr/include/c++/v1/__functional/hash.h:40:5: error: no member named 'memcpy' in namespace 'std::__1'; did you mean simply 'memcpy'? _VSTD::memcpy(&__r, __p, sizeof(__r)); ^~~~~~~ In file included from <built-in>:1: In file included from /Users/stephen/dev/Screenwriter/ScreenWriterX/ScreenWriterX/Screenwriter Sources/Screenwriter_Prefix.pch:505: In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk/usr/include/MacTypes.h:44: In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk/usr/include/c++/v1/stdbool.h:22: /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk/usr/include/c++/v1/__config:858:15: note: expanded from macro '_VSTD' #define _VSTD std::_LIBCPP_ABI_NAMESPACE ^ In file included from /Users/stephen/dev/Screenwriter/ScreenWriterX/ScreenWriterX/Screenwriter Sources/Text Engine/CThingEdit.cp:22: In file included from ../ScreenWriterX/ScreenWriterX/Screenwriter Sources/Text Engine/CThingEdit.h:61: In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk/usr/include/c++/v1/string:522: In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk/usr/include/c++/v1/algorithm:652: /Users/stephen/dev/Boost Libraries/boost_1_85_0/boost/compatibility/cpp_c_headers/cstring:22:11: note: 'memcpy' declared here using ::memcpy; ^ …this is for all sorts of symbols. ALSO: Showing All Errors Only /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk/usr/include/c++/v1/filesystem:2635:5: Use of undeclared identifier '_LIBCPP_UNREACHABLE' When including: #include <fstream> The libraries were build using: ./bootstrap.sh cxxflags="-arch x86_64 -arch arm64" cflags="-arch x86_64 -arch arm64" linkflags="-arch x86_64 -arch arm64" ./b2 toolset=clang-darwin target-os=darwin architecture=arm abi=aapcs cxxflags="-arch arm64" cflags="-arch arm64" linkflags="-arch arm64" -a mkdir -p arm64 && cp stage/lib/*.* arm64 ./b2 toolset=clang-darwin target-os=darwin architecture=x86 cxxflags="-arch x86_64" cflags="-arch x86_64" linkflags="-arch x86_64" abi=sysv binary-format=mach-o -a mkdir x86_64 && cp stage/lib/*.* x86_64 The intention was for me to eventually make UNIVERSAL dylibs using lipo – but for now, I just want to get my build back to functioning with Boost 1_85_0. NOTE that I’m continuing to use Boost’s Filesystem – even though I THINK Xcode’s C++20 might now support std::filesystem. I’ve searched all over for the answer – even consulted ChatGPT – but haven’t found a solution. But this seems like something bone-headed I’ve missed. Stephen

4 3

Re: [boost] A question for folks here
by me＠kennethreitz.org 11 Jul '24

11 Jul '24

Hi all, My name is Kenneth Reitz, and I got involved with Boost when Vinnie Falco asked me to join the C++ Alliance to work on the new boost website. You might recognize my name from the Python community, where I’m known for making Requests, Pipenv, and other tools. It’s nice to meet everyone! — Kenneth Reitz > 1. A question for folks here (David Sankel) > 2. Re: A secure string library? (Andrey Semashev) > 3. Re: A secure string library? (Andrey Semashev) > 4. Re: A question for folks here (Richard Hodges) > 5. Re: A secure string library? (Daniela Engert) > 6. Re: A secure string library? (Andrey Semashev) > 7. Re: A secure string library? (Christian Mazakas) > 8. Re: A question for folks here (Matt Borland) > 9. Re: A question for folks here (Christopher Kormanyos) > 10. Re: A question for folks here (Louis Tatta) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Wed, 10 Jul 2024 10:47:50 -0400 > From: David Sankel <camior(a)gmail.com> > To: Boost <boost(a)lists.boost.org> > Subject: [boost] A question for folks here > Message-ID: > <CAFYdOO+m95fKjxnKY3SY_eHC-X=PLs12BteaONG+QpS6fTCxcQ(a)mail.gmail.com> > Content-Type: text/plain; charset="UTF-8" > > For those who got involved in Boost within the last couple years, how did > you hear about boost? What attracted you to it? > > For those who have been around for a while, what keeps you here? Why do you > stay engaged? > > > ------------------------------ > > Message: 2 > Date: Wed, 10 Jul 2024 18:26:20 +0300 > From: Andrey Semashev <andrey.semashev(a)gmail.com> > To: boost(a)lists.boost.org > Subject: Re: [boost] A secure string library? > Message-ID: <6265cabd-c0b9-405e-98f4-8a47683e5472(a)gmail.com> > Content-Type: text/plain; charset=UTF-8 > > On 7/10/24 14:59, Peter Dimov via Boost wrote: >> Ruben Perez wrote: >>> There is OPENSSL_Cleanse, which does a similar job. I found it surprisingly >>> simple - I wonder if this is just enough or there are any corner cases where this >>> doesn't work: >>> https://github.com/openssl/openssl/blob/b544047c99c4a7413f793afe82ab1c165f8… >> >> That's an interesting approach. I can't offhand think of a reason why it wouldn't >> work. > > The compiler might convert OPENSSL_cleanse to something like this: > > void OPENSSL_cleanse(void *ptr, size_t len) > { > memset_t func = memset_func; > if (func != memset) > func(ptr, 0, len); > else > memset(ptr, 0, len); > } > > The purpose here is that, if memset_func is actually memset most of the > time, it can further optimize the call to memset, including to > completely remove it, depending on the call context. The > (well-predictable) branch is typically cheaper than an indirect call. I > think I've seen compilers do something along those lines as a result of > call devirtualization, especially with IPO and LTCG. > > I'm not saying that's what actually happens in OpenSSL, just that > something like this is possible. I think, a dummy asm statement is more > reliable and more efficient. > > void secure_cleanse(void *ptr, size_t len) > { > memset(ptr, 0, len); // a normal memset, optimizations are welcome > __asm__ __volatile__ ("" : : "r" (ptr), "r" (len) : "memory"); > } > > You can even make that function inline and it'll work, and in an optimal > way, too. > > > > ------------------------------ > > Message: 3 > Date: Wed, 10 Jul 2024 18:37:00 +0300 > From: Andrey Semashev <andrey.semashev(a)gmail.com> > To: boost(a)lists.boost.org > Subject: Re: [boost] A secure string library? > Message-ID: <57326885-13ab-4a73-ac5a-5aa6357e799c(a)gmail.com> > Content-Type: text/plain; charset=UTF-8 > > On 7/10/24 18:26, Andrey Semashev wrote: >> On 7/10/24 14:59, Peter Dimov via Boost wrote: >>> Ruben Perez wrote: >>>> There is OPENSSL_Cleanse, which does a similar job. I found it surprisingly >>>> simple - I wonder if this is just enough or there are any corner cases where this >>>> doesn't work: >>>> https://github.com/openssl/openssl/blob/b544047c99c4a7413f793afe82ab1c165f8… >>> >>> That's an interesting approach. I can't offhand think of a reason why it wouldn't >>> work. >> >> The compiler might convert OPENSSL_cleanse to something like this: >> >> void OPENSSL_cleanse(void *ptr, size_t len) >> { >> memset_t func = memset_func; >> if (func != memset) >> func(ptr, 0, len); >> else >> memset(ptr, 0, len); >> } >> >> The purpose here is that, if memset_func is actually memset most of the >> time, it can further optimize the call to memset, including to >> completely remove it, depending on the call context. The >> (well-predictable) branch is typically cheaper than an indirect call. I >> think I've seen compilers do something along those lines as a result of >> call devirtualization, especially with IPO and LTCG. >> >> I'm not saying that's what actually happens in OpenSSL, just that >> something like this is possible. I think, a dummy asm statement is more >> reliable and more efficient. >> >> void secure_cleanse(void *ptr, size_t len) >> { >> memset(ptr, 0, len); // a normal memset, optimizations are welcome >> __asm__ __volatile__ ("" : : "r" (ptr), "r" (len) : "memory"); >> } >> >> You can even make that function inline and it'll work, and in an optimal >> way, too. > > And for compilers that don't support __asm__, I think you could replace > it with: > > std::atomic_signal_fence(std::memory_order::acq_rel); > > > > ------------------------------ > > Message: 4 > Date: Wed, 10 Jul 2024 18:01:03 +0200 > From: Richard Hodges <hodges.r(a)gmail.com> > To: boost(a)lists.boost.org > Subject: Re: [boost] A question for folks here > Message-ID: > <CALvx3hYSO6svxz_aEw_LoaraweTguqW+jJScTyfymZAveOrXZg(a)mail.gmail.com> > Content-Type: text/plain; charset="UTF-8" > > On Wed, 10 Jul 2024 at 16:48, David Sankel via Boost <boost(a)lists.boost.org> > wrote: > >> For those who got involved in Boost within the last couple years, how did >> you hear about boost? What attracted you to it? >> > > I've been using boost as an essential force multiplier of C++ since version > 1.35 when Asio appeared, courtesy of Chris Kohlhoff. > > More recently in 2017, I needed an asynchronous websocket library for C++ > and lo-and-behold, boost had one, courtesy of Vinnie Falco. > > >> >> For those who have been around for a while, what keeps you here? Why do you >> stay engaged? >> > > After finishing a contract in which I used Boost.Beast et.al. in production > code, I took up an offer by the C++ Alliance to become a maintainer of it. > A bit of a "Victor Kiam" moment, if you will. > > While working for the C++ Alliance I was also involved in the design and > first cut of Boost.Json and had some input into Boost.Url, another two very > keenly needed libraries sponsored by the C++ Alliance. > I am no longer working for the C++ Alliance, but maintain a warm > relationship with the organisation. > > I am currently using Boost.Cobalt in a financial trading software suite. > > I stay engaged because: > - I don't want to have to switch languages - C++ is perfectly fine for me. > - Boost polyfills all the essential functionality that the children running > WG21 continue to refuse to provide. > - It's convenient to have one library that provides (almost) every tool I > need. > > My very great thanks to the original authors and contributors, and more > recently to the C++ Alliance, which as far as I can see is the only major > sponsor of Boost. > Without this organisation's involvement, I believe the libraries would have > been allowed to fall into disrepair a long time ago. > > I don't think I have met more than one team in the financial industry which > uses C++ but which does not use Boost. > > On a separate note, I was deeply disappointed by your recent public > outbursts, David. > > Sincerely, > > Richard Hodges > A C++phile > ex maintainer of Boost.Beast > contributor to Boost.Json, Boost.Url > Advisor to Boost.MySQL, Boost.Cobalt > > >> >> _______________________________________________ >> Unsubscribe & other changes: >> http://lists.boost.org/mailman/listinfo.cgi/boost >> > > > ------------------------------ > > Message: 5 > Date: Wed, 10 Jul 2024 18:13:41 +0200 > From: Daniela Engert <dani(a)ngrt.de> > To: boost(a)lists.boost.org > Subject: Re: [boost] A secure string library? > Message-ID: <98140e71-ef1e-431a-a089-e24f56e390bd(a)ngrt.de> > Content-Type: text/plain; charset=UTF-8; format=flowed > > Am 10.07.2024 um 17:37 schrieb Andrey Semashev via Boost: >> On 7/10/24 18:26, Andrey Semashev wrote: >>> On 7/10/24 14:59, Peter Dimov via Boost wrote: >>>> Ruben Perez wrote: >>>>> There is OPENSSL_Cleanse, which does a similar job. I found it surprisingly >>>>> simple - I wonder if this is just enough or there are any corner cases where this >>>>> doesn't work: >>>>> https://github.com/openssl/openssl/blob/b544047c99c4a7413f793afe82ab1c165f8… >>>> That's an interesting approach. I can't offhand think of a reason why it wouldn't >>>> work. >>> The compiler might convert OPENSSL_cleanse to something like this: >>> >>> void OPENSSL_cleanse(void *ptr, size_t len) >>> { >>> memset_t func = memset_func; >>> if (func != memset) >>> func(ptr, 0, len); >>> else >>> memset(ptr, 0, len); >>> } >>> >>> The purpose here is that, if memset_func is actually memset most of the >>> time, it can further optimize the call to memset, including to >>> completely remove it, depending on the call context. The >>> (well-predictable) branch is typically cheaper than an indirect call. I >>> think I've seen compilers do something along those lines as a result of >>> call devirtualization, especially with IPO and LTCG. >>> >>> I'm not saying that's what actually happens in OpenSSL, just that >>> something like this is possible. I think, a dummy asm statement is more >>> reliable and more efficient. >>> >>> void secure_cleanse(void *ptr, size_t len) >>> { >>> memset(ptr, 0, len); // a normal memset, optimizations are welcome >>> __asm__ __volatile__ ("" : : "r" (ptr), "r" (len) : "memory"); >>> } >>> >>> You can even make that function inline and it'll work, and in an optimal >>> way, too. >> And for compilers that don't support __asm__, I think you could replace >> it with: >> >> std::atomic_signal_fence(std::memory_order::acq_rel); >> > I think Peter is actually right in his assessment: > > While 'memset_func' is TU-local, it is also 'volatile'. This implies > every look at it might reveal a different content. Therefore the > necessity for non-constness and dynamic initialization. We humans see > that the variable can't change its value other than in the > initialization. The compiler can't reason that because said properties > are the only ones known during the compilation of 'OPENSSL_cleanse()'. > It can't perform unbounded look-ahead until the end of the TU like we do. > > Dani > > -- > PGP/GPG: 2CCB 3ECB 0954 5CD3 B0DB 6AA0 BA03 56A1 2C4638C5 > > ------------------------------ > > Message: 6 > Date: Wed, 10 Jul 2024 19:24:48 +0300 > From: Andrey Semashev <andrey.semashev(a)gmail.com> > To: boost(a)lists.boost.org > Subject: Re: [boost] A secure string library? > Message-ID: <905dd5f7-5d29-48ab-87aa-6aa0a23e60c6(a)gmail.com> > Content-Type: text/plain; charset=UTF-8 > > On 7/10/24 19:13, Daniela Engert via Boost wrote: >> Am 10.07.2024 um 17:37 schrieb Andrey Semashev via Boost: >>> On 7/10/24 18:26, Andrey Semashev wrote: >>>> On 7/10/24 14:59, Peter Dimov via Boost wrote: >>>>> Ruben Perez wrote: >>>>>> There is OPENSSL_Cleanse, which does a similar job. I found it >>>>>> surprisingly >>>>>> simple - I wonder if this is just enough or there are any corner >>>>>> cases where this >>>>>> doesn't work: >>>>>> https://github.com/openssl/openssl/blob/b544047c99c4a7413f793afe82ab1c165f8… >>>>> That's an interesting approach. I can't offhand think of a reason >>>>> why it wouldn't >>>>> work. >>>> The compiler might convert OPENSSL_cleanse to something like this: >>>> >>>> ?? void OPENSSL_cleanse(void *ptr, size_t len) >>>> ?? { >>>> ???? memset_t func = memset_func; >>>> ???? if (func != memset) >>>> ?????? func(ptr, 0, len); >>>> ???? else >>>> ?????? memset(ptr, 0, len); >>>> ?? } >>>> >>>> The purpose here is that, if memset_func is actually memset most of the >>>> time, it can further optimize the call to memset, including to >>>> completely remove it, depending on the call context. The >>>> (well-predictable) branch is typically cheaper than an indirect call. I >>>> think I've seen compilers do something along those lines as a result of >>>> call devirtualization, especially with IPO and LTCG. >>>> >>>> I'm not saying that's what actually happens in OpenSSL, just that >>>> something like this is possible. I think, a dummy asm statement is more >>>> reliable and more efficient. >>>> >>>> ?? void secure_cleanse(void *ptr, size_t len) >>>> ?? { >>>> ???? memset(ptr, 0, len); // a normal memset, optimizations are welcome >>>> ???? __asm__ __volatile__ ("" : : "r" (ptr), "r" (len) : "memory"); >>>> ?? } >>>> >>>> You can even make that function inline and it'll work, and in an optimal >>>> way, too. >>> And for compilers that don't support __asm__, I think you could replace >>> it with: >>> >>> ?? std::atomic_signal_fence(std::memory_order::acq_rel); >>> >> I think Peter is actually right in his assessment: >> >> While 'memset_func' is TU-local, it is also 'volatile'. This implies >> every look at it might reveal a different content. Therefore the >> necessity for non-constness and dynamic initialization. We humans see >> that the variable can't change its value other than in the >> initialization. The compiler can't reason that because said properties >> are the only ones known during the compilation of 'OPENSSL_cleanse()'. >> It can't perform unbounded look-ahead until the end of the TU like we do. > > With volatile, the compiler is not allowed to optimize away or reorder > loads and stores of the variable. There's no restriction on what the > compiler is allowed to do with the loaded value. > > > > ------------------------------ > > Message: 7 > Date: Wed, 10 Jul 2024 10:10:43 -0700 > From: Christian Mazakas <christian.mazakas(a)gmail.com> > To: boost(a)lists.boost.org > Subject: Re: [boost] A secure string library? > Message-ID: > <CAHf7xWueD5=ekMC178pikzH2iuhAtyzC6v5UgPBSoj0NMy3y9Q(a)mail.gmail.com> > Content-Type: text/plain; charset="UTF-8" > >> Andrey Semashev via Boost: >> With volatile, the compiler is not allowed to optimize away or reorder >> loads and stores of the variable. There's no restriction on what the >> compiler is allowed to do with the loaded value. > > It could insert a branch against `memset` but that seems really only like a > theoretical > optimization. > > This is an example where the volatile preserves the secure_erase() call: > https://godbolt.org/z/854jfarb9 > > Kind of neat trying to get the compiler to elide this stuff. You were > right, Andrey, you really need > LTO and LTCG and the like to get this kind of behavior. Super neat stuff. > > Idk, seems like whatever OpenSSL is doing is Sound Enough in practice. > > I'd be curious to know if it's actually sound for a compiler to make that > kind of optimization or at least > what are the limits on how far a compiler can actually go to ensure > soundness. If you know those limits, > you can probably make this pattern work reliably. > > - Christian > > > ------------------------------ > > Message: 8 > Date: Wed, 10 Jul 2024 17:57:57 +0000 > From: Matt Borland <matt(a)mattborland.com> > To: boost(a)lists.boost.org > Subject: Re: [boost] A question for folks here > Message-ID: > <LQ-gmVceAUPyCRzsmP5gN1Z4NJiwrRtJ-yJY5Q6Ne-3SnJ_omC84hltKP9AbS3x-TVlz35Amln3jW0CBdG0nnzAioM53fxXobq0GO3zYb2E=(a)mattborland.com> > > Content-Type: text/plain; charset="utf-8" > > >> For those who got involved in Boost within the last couple years, how did >> you hear about boost? > > I heard about it from a university professor as a freshman undergraduate student in 2011. Since C++11 was just coming about, and the speed of updating toolchains in academia is slow so we were stuck in the C++03 days on old RHEL systems. > >> What attracted you to it? > > I was studying aeronautical engineering so having pre-made libraries like Boost.Math, Boost.Multiprecision, and ODEint were useful to me. I could focus on the problem at hand rather than having to roll my own special functions, solvers, big numbers, constants, etc. > >> For those who have been around for a while, what keeps you here? Why do you stay engaged? > > I started to get involved with development during the COVID lockdowns because like many people I found myself with quite a bit of extra free time. What hooked me was learning from and working with extremely competent programmers and mathematicians like John Maddock, Chris Kormanyos, and Nick Thompson. I was hired by the C++ Alliance at the beginning of 2023 and they have sponsored my development since. This allows me to work on new (https://github.com/cppalliance/decimal) and existing libraries (charconv, math, multiprecision, random, etc) in a way that I was never able to on a volunteer basis with a full time job. The community is large, knowledgeable, and helpful so I continue to enjoy working on Boost. > > > I think it would be beneficial to the developer community for the Boost Foundation board members to also answer these questions. Frankly some even require introductions with their answers. There are members of the board like Peter, Glen, and Zach that are Titans of Boost, and those like Kristen who I had not heard of until her post about wanting to cut ties with the C++ Alliance. Having unknown members of the Boost Foundation runs counter to their mission statement whereby the board intends to achieve its mission by "fostering community engagement, [and] nurturing leaders..."[1]. > > Matt > > [1] https://sites.google.com/boost.org/boost-foundation/home >

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A secure string library?
by Ruben Perez 10 Jul '24

10 Jul '24

Hi all, Boost.MySQL and Boost.Redis need to hold sensitive information, like passwords, to work. Using std::string may be sufficient for many use cases, but it's not the best security practice. std::string doesn't wipe its memory on cleanup, resulting in the password remaining in memory for an indeterminate amount of time. Other languages like C# implement a SecureString class that wipes memory on destruction. Crypto++ implements a similar concept, but it's a big dependency I'm not willing to take. I'd like to know whether everyone else's opinion on this: * Have you faced this issue before? * Do you think this is something we (as Boost authors) should care about, or am I thinking too much? * Do you think a library implementing secure string/array/buffer classes would be a valuable addition to Boost? Thanks, Ruben.

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[boost 1.85.0 MSVC142-64 ]type_name.hpp(354,2): error C2766: explicit specialization; 'boost::core::detail::tn_holder<unsigned short>' has already been defined
by Bhuyan, Jyotideep 10 Jul '24

10 Jul '24

Hello, I am updating my code from boost version 1.78 to boost 1.85. and facing build issues "error C2766: explicit specialization; 'boost::core::detail::tn_holder<unsigned short>' has already been defined" Below is the error that I am facing that needs your help. I could not find any code or direct header file inclusion in my code related to the below error. C:\<my boost>\boost_1_85\boost\boost\core\type_name.hpp(354,2): error C2766: explicit specialization; 'boost::core::detail::tn_holder<unsigned short>' has already been defined. C:\<my boost>\boost_1_85\boost\boost\core\type_name.hpp(273): message : see previous definition of 'tn_holder<unsigned short> Please note that after upgrading to boost 1.85, the compiler was not able to find "#include <boost/function/detail/prologue.hpp>", I checked this file is not present in the new version. Hence, I have commented header file inclusion in my code. I am building the code for MSVC142 (C++14) for 64-bit Windows 10 architecture. Best Regards, Jyotideep (JD) Please be advised that this email may contain confidential information. If you are not the intended recipient, please notify us by email by replying to the sender and delete this message. The sender disclaims that the content of this email constitutes an offer to enter into, or the acceptance of, any agreement; provided that the foregoing does not invalidate the binding effect of any digital or other electronic reproduction of a manual signature that is included in any attachment. Confidential - Company Proprietary

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failure to produce PDF documentation
by Robert Ramey 10 Jul '24

10 Jul '24

For many years, I've been using the xslt based system for converting boostbook xml into html an pdf files. Once I got it set up, I've never had a problem. But now, it is failing with some error messages provoked by the contents of some xml files which are part of boost book. A casual review of the correspondng github repository shows the that the some of these files have been "maintained" recently ... some as recently as 3 days ago. Could someone (probably the maintainer) look into this. I noticed that when I try to appy this to the safe numerics library. The following should reproduce the problem: cd /Users/robertramey/WorkingProjects/modular-boost/libs/safe_numerics/doc/boostbook $ls *.sh makeepub.sh makehtml.sh makepdf.sh makeproposal.sh $echo $PATH /Volumes/public/fop-2.1:.:/Volumes/public/menu_bash:/usr/local/bin:/System/Cryptexes/App/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/local/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/appleinternal/bin:/Library/Apple/usr/bin $./makepdf.sh [Fatal Error] docbook.xsl:6:3: The element type "hr" must be terminated by the matching end-tag "</hr>". http://docbook.sourceforge.net/release/xsl/current/fo/docbook.xsl; Line #6; Column #3; org.xml.sax.SAXParseException; systemId: http://docbook.sourceforge.net/release/xsl/current/fo/docbook.xsl; lineNumber: 6; columnNumber: 3; The element type "hr" must be terminated by the matching end-tag "</hr>". Jul 09, 2024 2:58:38 PM org.apache.fop.cli.Main startFOP SEVERE: Exception ... Thanks to whoever looks into this. Robert Ramey

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Boost 1.85, Windows, VS2022 17.10.3, build does not create any libs on building boost
by Dennis Luehring 09 Jul '24

09 Jul '24

my system Windows 10 x64, VS2022 10.7.3 Download: https://archives.boost.io/release/1.85.0/source/boost_1_85_0.7z unpack zip to boost_1_85_0 in console: cd boost_1_85_0 bootstrap.bat b2 -j%NUMBER_OF_PROCESSORS% toolset=msvc-14.3 address-model=64 --stagedir=.\lib64-msvc-14.3 --build-dir=.\__build --build-type=complete threading=multi architecture=x86 stage --with-date_time --with-graph --with-nowide --with-test --width-config --with-system --with-filesystem --with-serialization --with-locale --with-log result - lib64-msvc-14.3\lib\cmake gets created - but no libs that is my default build style up to 1.84 the output of bootstrap.bat https://pastebin.com/DQUVe3QR the output of b2 run https://pastebin.com/sJqGLDE7 it seems that all libs are ignored someway any idea?

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[release] Master branch closes for the 1.86.0 beta release on WEDNESDAY
by Marshall Clow 08 Jul '24

08 Jul '24

Calendar is here: https://www.boost.org/development/ — The Release Managers

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New Boost website ready for launch
by Joaquin M López Muñoz 06 Jul '24

06 Jul '24

Hi everyone, As most of you know, the new Boost website has been in the works for quite a long time: last week we've fixed the last showstopper issues and are now in a position to launch it publicly and announce to the wider community! See the launch-ready website at: https://boost.io The new website is ready to replace the current one at boost.org any time we want. The old site has served us well for 25 years, and it deserves to be given a retirement permit. OVERVIEW The new website is organized in five top-level sections: * News: an aggregator of internal announcements, blog articles, videos, etc. related to the Boost project. * Learn: comprehensive and completely rewritten tutorials and reference material for users, contributors and review participants. Check this out: there's a ton of new stuff here. * Community: links to the various discussion venues for Boost (mailing lists, Slack groups, X, etc.). * Libraries: revamped directory of Boost libraries, with integrated access to version-specific docs, repos, and more. * Releases: access to release notes, download binaries and source code for all Boost versions from 1.16.1 up to the current one. Users can navigate the website anonymously or log in to be able to contribute to the News section, receive notifications etc. The site uses responsive design to work on wide screens as well as your mobile device. Also, check the light and dark modes at the top-right corner :-) FEEDBACK AND FUTURE The evolution of the website does not stop here. We have quite a backlog of issues and new features registered at: https://github.com/boostorg/website-v2/issues https://github.com/boostorg/website-v2-docs/issues But we're also expecting your feedback! Please let us know what you think of the website and ways to improve it. I will personally make sure that all comments and suggestions are properly addressed. Ways to contribute: * Through the mailing list or the #boost-website group at cpplang.slack.com. * Filing issues directly at https://github.com/boostorg/website-v2 (website proper) and https://github.com/boostorg/website-v2 (learning material). * Learning material has an "Edit this page" link from where you can fork any documentation section and propose changes through a pull request. * Reach out to me anyway you'd like. ACKNOWLEDGEMENTS There are just too many individuals to list here who had contributed to the new website --my thanks to all of them. Let me mention some of the people I have worked with the most in the last two months, when I took over the PM role for this launch effort. * The people at REVSYS (Frank Wiles, Lacey Henschel) and Spencer Strickland built the Django-based backend and most of the frontend. Kenneth Reitz and Julio C. Estrada have been working tirelessly to close functionality gaps and fix remaining issues up to launch status. * Peter Turcan is the main author of the new learning material featured in the website. Again, check it out and help us spot glitches or propose new topics to work on. * Sam Darwin, who's already the Atlas upon whom the current Boost infrastructure rests, has double down on his responsibilites to set up and take care of this new backend. * René Rivera wrote many of the scripts that power the old website and has assisted us in the migration process with his expertise and unique insights into the particulars of Boost internal procedures. * Many people have filed issues during development, but the record holder is Andrey Semashev (39 tickets and counting). His suggestions and active involvement in the fixing process have made the website a better place. Best, Joaquín M López Muñoz

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[release] The 1.86.0 release will close for major changes WEDNESDAY
by Marshall Clow 02 Jul '24

02 Jul '24

Calendar here: https://www.boost.org/development/ Next deadline: The master branch will close for the beta next Wednesday. — The release managers

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