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On 10/3/15 4:13 AM, Mike Frysinger wrote: |
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> Title: GCC 5 Defaults to the New C++11 ABI |
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> Author: Mike Frysinger <vapier@g.o> |
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> Content-Type: text/plain |
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> Posted: 2015-10-02 |
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> Revision: 1 |
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> News-Item-Format: 1.0 |
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> Display-If-Installed: >=sys-devel/gcc-5 |
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> |
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> GCC 5 uses the new C++ ABI by default. When building new code, you might run |
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> into link time errors like: |
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> ...: undefined reference to '_ZNSt6chrono12steady_clock3nowEv@GLIBCXX_3.4.17' |
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> Or you might see linkage failures with "std::__cxx11::string" in the output. |
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> |
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> These are signs that you need to rebuild packages using the new C++ ABI. |
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> You can quickly do so by using revdep-rebuild like so: |
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> # revdep-rebuild --library 'libstdc\+\+\.so\.6' |
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> |
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> For more details, feel free to peruse: |
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> https://developerblog.redhat.com/2015/02/05/gcc5-and-the-c11-abi/ |
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> https://blogs.gentoo.org/blueness/2015/03/10/the-c11-abi-incompatibility-problem-in-gentoo/ |
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Curious, can one reasonably easy downgrade from GCC 5 back to GCC 4? |
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Are there any instructions for that? Is it sufficient to do a similar |
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revdep-rebuild command? |
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In case the downgrade would horribly break systems or be otherwise |
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highly nontrivial, I'd recommend some note for that. |
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Paweł |
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