C++ missing symbol

Developer Tools & Services Xcode
kithrup OP
Created Feb ’23
Replies 15
Boosts 0
Views 1.9k
Participants 2 
#include <stdio.h>
#include <sstream>

int
main(int ac, char **av)
{
		std::__1::basic_ostringstream<char, std::__1::char_traits<char>, std::__1::allocator<char> > x;
		x << "How now brown cow";
		return 0;
}

If I build this on macOS 12, and try to run the binary on macOS 11, it fails because that symbol is not present in /usr/lib/libc++.1.dylib. If I compile it on macOS 11, and run on 11 or later, it works.

Is this correct behaviour? Since the dylib version didn't change, I would expect that to mean no ABI changes.

Answered by kithrup in 744628022

And solved -- it needs to have -target ${arch}-apple-${os}${version}, eg x86_64-apple-macos11.5. And yes, it was vcpkg doing this. I can fix it by editing the triplets file, or I might some day do up a better diff and see how that goes. Or we could just drop support of macOS 11. But options, yay!

Replies  15
Boosts  0
Views  1.9k
Participants  2
kithrup OP
Feb ’23

Note that C++ is far far far from my strong suit, I'm just trying to figure out why our application no longer works on macOS 11 just because we started building it on macOS 12.

0
endecotp OP
Feb ’23

Why are you writing std::__1 ?

I would say that that's undefined behaviour, unless you know something I don't.

0
kithrup OP
Feb ’23

Because the more-c++-capable coworkers weren't able to give me a terribly small example, so I just used the pretty version of the undefined symbol. As I said, it works if I compile it on macOS 11 and run it on 11 and later, but if I compile it on macOS 12, it won't run on macOS 11. And I find this confusing.

0
kithrup OP
Feb ’23

Changing the line to std::basic_ostringstream<char, std::char_traits<char>, std::allocator<char> > x; results in the same behaviour.

0
endecotp OP
Feb ’23

How are you compiling it?

0
kithrup OP
Feb ’23

My sample program? c++ -g t.cc -o t

Our application is built using cmake, which creates a .xcodeproj and runs xcodebuild. As I said (I think?), I'm not sure what particular bit of our code is triggering it. We've tried using -isysroot and setting the deployment target to 11.5, but it's still using /usr/lib/libc++.1.dylib and, well, see first comment about that.

0
endecotp OP
Feb ’23

(BTW, std::basic_ostringstream<char, std::char_traits<char>, std::allocator<char> > is the same as std::ostringstream.)

0
kithrup OP
Feb ’23

Oh, that'll help me find it, I think.

0
endecotp OP
Feb ’23

It might be interesting to see what c++ --verbose says.

0
kithrup OP
Feb ’23

On macOS 11:

Apple clang version 12.0.5 (clang-1205.0.22.11)
Target: x86_64-apple-darwin20.5.0
Thread model: posix
InstalledDir: /Library/Developer/CommandLineTools/usr/bin
 "/Library/Developer/CommandLineTools/usr/bin/clang" -cc1 -triple x86_64-apple-macosx11.0.0 -Wdeprecated-objc-isa-usage -Werror=deprecated-objc-isa-usage -Werror=implicit-function-declaration -emit-obj -mrelax-all -disable-free -disable-llvm-verifier -discard-value-names -main-file-name t.cc -mrelocation-model pic -pic-level 2 -mframe-pointer=all -fno-strict-return -fno-rounding-math -munwind-tables -target-sdk-version=12.1 -fvisibility-inlines-hidden-static-local-var -target-cpu penryn -debugger-tuning=lldb -target-linker-version 650.9 -v -resource-dir /Library/Developer/CommandLineTools/usr/lib/clang/12.0.5 -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX12.1.sdk -I/usr/local/include -stdlib=libc++ -internal-isystem /Library/Developer/CommandLineTools/SDKs/MacOSX12.1.sdk/usr/include/c++/v1 -internal-isystem /Library/Developer/CommandLineTools/SDKs/MacOSX12.1.sdk/usr/local/include -internal-isystem /Library/Developer/CommandLineTools/usr/lib/clang/12.0.5/include -internal-externc-isystem /Library/Developer/CommandLineTools/SDKs/MacOSX12.1.sdk/usr/include -internal-externc-isystem /Library/Developer/CommandLineTools/usr/include -Wno-reorder-init-list -Wno-implicit-int-float-conversion -Wno-c99-designator -Wno-final-dtor-non-final-class -Wno-extra-semi-stmt -Wno-misleading-indentation -Wno-quoted-include-in-framework-header -Wno-implicit-fallthrough -Wno-enum-enum-conversion -Wno-enum-float-conversion -Wno-elaborated-enum-base -fdeprecated-macro -fdebug-compilation-dir /Users/sef -ferror-limit 19 -stack-protector 1 -fstack-check -mdarwin-stkchk-strong-link -fblocks -fencode-extended-block-signature -fregister-global-dtors-with-atexit -fgnuc-version=4.2.1 -fcxx-exceptions -fexceptions -fmax-type-align=16 -fcommon -clang-vendor-feature=+disableNonDependentMemberExprInCurrentInstantiation -fno-odr-hash-protocols -mllvm -disable-aligned-alloc-awareness=1 -o /var/folders/m6/s94tzxq53p568j_kqqxyk3d40000gn/T/t-78ad5e.o -x c++ /tmp/t.cc
clang -cc1 version 12.0.5 (clang-1205.0.22.11) default target x86_64-apple-darwin20.5.0
ignoring nonexistent directory "/usr/local/include"
ignoring nonexistent directory "/Library/Developer/CommandLineTools/SDKs/MacOSX12.1.sdk/usr/local/include"
ignoring nonexistent directory "/Library/Developer/CommandLineTools/SDKs/MacOSX12.1.sdk/Library/Frameworks"
#include "..." search starts here:
#include <...> search starts here:
 /Library/Developer/CommandLineTools/SDKs/MacOSX12.1.sdk/usr/include/c++/v1
 /Library/Developer/CommandLineTools/usr/lib/clang/12.0.5/include
 /Library/Developer/CommandLineTools/SDKs/MacOSX12.1.sdk/usr/include
 /Library/Developer/CommandLineTools/usr/include
 /Library/Developer/CommandLineTools/SDKs/MacOSX12.1.sdk/System/Library/Frameworks (framework directory)
End of search list.
 "/Library/Developer/CommandLineTools/usr/bin/ld" -demangle -lto_library /Library/Developer/CommandLineTools/usr/lib/libLTO.dylib -no_deduplicate -dynamic -arch x86_64 -platform_version macos 11.0.0 12.1 -syslibroot /Library/Developer/CommandLineTools/SDKs/MacOSX12.1.sdk -o a.out -L/usr/local/lib /var/folders/m6/s94tzxq53p568j_kqqxyk3d40000gn/T/t-78ad5e.o -lc++ -lSystem /Library/Developer/CommandLineTools/usr/lib/clang/12.0.5/lib/darwin/libclang_rt.osx.a
0
kithrup OP
Feb ’23

And on macOS 12: On macOS 12:

Apple clang version 14.0.0 (clang-1400.0.29.202)
Target: x86_64-apple-darwin21.6.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
 "/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang" -cc1 -triple x86_64-apple-macosx12.0.0 -Wundef-prefix=TARGET_OS_ -Wdeprecated-objc-isa-usage -Werror=deprecated-objc-isa-usage -Werror=implicit-function-declaration -emit-obj -mrelax-all --mrelax-relocations -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name t.cc -mrelocation-model pic -pic-level 2 -mframe-pointer=all -fno-strict-return -fno-rounding-math -funwind-tables=2 -target-sdk-version=13.1 -fvisibility-inlines-hidden-static-local-var -target-cpu penryn -tune-cpu generic -debug-info-kind=standalone -dwarf-version=4 -debugger-tuning=lldb -target-linker-version 820.1 -v -resource-dir /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/14.0.0 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk -I/usr/local/include -stdlib=libc++ -internal-isystem /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1 -internal-isystem /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/local/include -internal-isystem /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/14.0.0/include -internal-externc-isystem /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include -internal-externc-isystem /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include -Wno-reorder-init-list -Wno-implicit-int-float-conversion -Wno-c99-designator -Wno-final-dtor-non-final-class -Wno-extra-semi-stmt -Wno-misleading-indentation -Wno-quoted-include-in-framework-header -Wno-implicit-fallthrough -Wno-enum-enum-conversion -Wno-enum-float-conversion -Wno-elaborated-enum-base -Wno-reserved-identifier -Wno-gnu-folding-constant -Wno-cast-function-type -Wno-bitwise-instead-of-logical -fdeprecated-macro -fdebug-compilation-dir=/Users/sef/Downloads/ExtensionPermission_7160_Crashes -ferror-limit 19 -stack-protector 1 -fstack-check -mdarwin-stkchk-strong-link -fblocks -fencode-extended-block-signature -fregister-global-dtors-with-atexit -fgnuc-version=4.2.1 -fno-cxx-modules -fcxx-exceptions -fexceptions -fmax-type-align=16 -fcommon -clang-vendor-feature=+messageToSelfInClassMethodIdReturnType -clang-vendor-feature=+disableInferNewAvailabilityFromInit -clang-vendor-feature=+disableNonDependentMemberExprInCurrentInstantiation -fno-odr-hash-protocols -clang-vendor-feature=+enableAggressiveVLAFolding -clang-vendor-feature=+revert09abecef7bbf -clang-vendor-feature=+thisNoAlignAttr -clang-vendor-feature=+thisNoNullAttr -mllvm -disable-aligned-alloc-awareness=1 -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /var/folders/x4/bk1vl6m88xjfxq006s6sv2s00000gn/T/t-8daa50.o -x c++ /tmp/t.cc
clang -cc1 version 14.0.0 (clang-1400.0.29.202) default target x86_64-apple-darwin21.6.0
ignoring nonexistent directory "/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/local/include"
ignoring nonexistent directory "/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/Library/Frameworks"
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/include
 /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1
 /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/14.0.0/include
 /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include
 /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include
 /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks (framework directory)
End of search list.
 "/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ld" -demangle -lto_library /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/libLTO.dylib -no_deduplicate -dynamic -arch x86_64 -platform_version macos 12.0.0 13.1 -syslibroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk -o /tmp/t -L/usr/local/lib /var/folders/x4/bk1vl6m88xjfxq006s6sv2s00000gn/T/t-8daa50.o -lc++ -lSystem /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/14.0.0/lib/darwin/libclang_rt.osx.a
 "/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/dsymutil" -o /tmp/t.dSYM /tmp/t
0
kithrup OP
Feb ’23

Yes, using std::ostreamstring by itself does the trick. And again, this isn't making any sense to me. I compiled up the same program (using c++ -g t.cc -o macos<whatever>) and did:

nm macos11 | grep ostreamIc | sort | grep U ; echo '****' ; nm macos12 | grep ostreamIc | sort | grep U
                 U __ZNSt3__113basic_ostreamIcNS_11char_traitsIcEEE6sentryC1ERS3_
                 U __ZNSt3__113basic_ostreamIcNS_11char_traitsIcEEE6sentryD1Ev
                 U __ZNSt3__113basic_ostreamIcNS_11char_traitsIcEEED0Ev
                 U __ZNSt3__113basic_ostreamIcNS_11char_traitsIcEEED1Ev
                 U __ZNSt3__113basic_ostreamIcNS_11char_traitsIcEEED2Ev
                 U __ZTINSt3__113basic_ostreamIcNS_11char_traitsIcEEEE
                 U __ZTv0_n24_NSt3__113basic_ostreamIcNS_11char_traitsIcEEED0Ev
                 U __ZTv0_n24_NSt3__113basic_ostreamIcNS_11char_traitsIcEEED1Ev
****
                 U __ZNSt3__113basic_ostreamIcNS_11char_traitsIcEEE6sentryC1ERS3_
                 U __ZNSt3__113basic_ostreamIcNS_11char_traitsIcEEE6sentryD1Ev
                 U __ZNSt3__113basic_ostreamIcNS_11char_traitsIcEEED2Ev

which to me looks like macos12 has fewer undefineds, but the ones it does have are in the same set as macos11.

Is this a bug?

0
endecotp OP
Feb ’23

Sorry, I've no idea what's going on there, this is beyond my understanding of how it's supposed to work.

0
kithrup OP
Feb ’23

Ok. So: if I use Xcode to build (and set the Deployment Target to 11.5), then the resulting binary works.

We use vcpkg to manage a bunch of 3rd party libraries, and I'm going to guess that's the cause there -- it doesn't build with xcodebuild, and doesn't have a .xcodeproj bundle. I'm not sure what xcodebuild is doing differently in its invocations, but I could try to go down that rabbithole. 😄

0
kithrup OP
Feb ’23
Accepted Answer

And solved -- it needs to have -target ${arch}-apple-${os}${version}, eg x86_64-apple-macos11.5. And yes, it was vcpkg doing this. I can fix it by editing the triplets file, or I might some day do up a better diff and see how that goes. Or we could just drop support of macOS 11. But options, yay!

0
C++ missing symbol
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