Bug#897805: llvm-toolchain-5.0: ftbfs with GCC-8

[Matthias Klose]

Package: src:llvm-toolchain-5.0
Version: 1:5.0.1-4
Severity: normal
Tags: sid buster
User: debian-gcc at lists.debian.org
Usertags: ftbfs-gcc-8

Please keep this issue open in the bug tracker for the package it
was filed for.  If a fix in another package is required, please
file a bug for the other package (or clone), and add a block in this
package. Please keep the issue open until the package can be built in
a follow-up test rebuild.

The package fails to build in a test rebuild on at least amd64 with
gcc-8/g++-8, but succeeds to build with gcc-7/g++-7. The
severity of this report will be raised before the buster release.

The full build log can be found at:
http://aws-logs.debian.net/2018/05/01/gcc8/llvm-toolchain-5.0_5.0.1-4_unstable_gcc8.log.gz
The last lines of the build log are at the end of this report.

To build with GCC 8, either set CC=gcc-8 CXX=g++-8 explicitly,
or install the gcc, g++, gfortran, ... packages from experimental.

  apt-get -t=experimental install g++ 

Common build failures are new warnings resulting in build failures with
-Werror turned on, or new/dropped symbols in Debian symbols files.
For other C/C++ related build failures see the porting guide at
http://gcc.gnu.org/gcc-8/porting_to.html

[...]
     struct pair
            ^~~~
cc1plus: warning: unrecognized command line option '-Wno-vla-extension'
cc1plus: warning: unrecognized command line option '-Wno-deprecated-register'
In file included from /<<PKGBUILDDIR>>/include/llvm/ADT/STLExtras.h:32,
                 from /<<PKGBUILDDIR>>/include/llvm/ADT/StringRef.h:13,
                 from /<<PKGBUILDDIR>>/tools/lldb/include/lldb/lldb-private-enumerations.h:13,
                 from /<<PKGBUILDDIR>>/tools/lldb/include/lldb/lldb-private.h:16,
                 from /<<PKGBUILDDIR>>/tools/lldb/include/lldb/Symbol/CompilerType.h:22,
                 from /<<PKGBUILDDIR>>/tools/lldb/include/lldb/Symbol/TaggedASTType.h:13,
                 from /<<PKGBUILDDIR>>/tools/lldb/source/Plugins/ExpressionParser/Clang/IRForTarget.h:14,
                 from /<<PKGBUILDDIR>>/tools/lldb/source/Plugins/ExpressionParser/Clang/IRForTarget.cpp:10:
/<<PKGBUILDDIR>>/include/llvm/ADT/SmallVector.h: In instantiation of 'void llvm::SmallVectorTemplateBase<T, true>::push_back(const T&) [with T = std::pair<void*, long unsigned int>]':
/<<PKGBUILDDIR>>/include/llvm/Support/Allocator.h:247:33:   required from 'void* llvm::BumpPtrAllocatorImpl<AllocatorT, SlabSize, SizeThreshold>::Allocate(size_t, size_t) [with AllocatorT = llvm::MallocAllocator; long unsigned int SlabSize = 4096; long unsigned int SizeThreshold = 4096; size_t = long unsigned int]'
/<<PKGBUILDDIR>>/tools/clang/include/clang/AST/ASTContext.h:624:42:   required from here
/<<PKGBUILDDIR>>/include/llvm/ADT/SmallVector.h:309:11: warning: 'void* memcpy(void*, const void*, size_t)' writing to an object of type 'struct std::pair<void*, long unsigned int>' with no trivial copy-assignment; use copy-assignment or copy-initialization instead [-Wclass-memaccess]
     memcpy(this->end(), &Elt, sizeof(T));
     ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/8/utility:70,
                 from /usr/include/c++/8/tuple:38,
                 from /usr/include/c++/8/functional:54,
                 from /<<PKGBUILDDIR>>/tools/lldb/include/lldb/Symbol/CompilerType.h:15,
                 from /<<PKGBUILDDIR>>/tools/lldb/include/lldb/Symbol/TaggedASTType.h:13,
                 from /<<PKGBUILDDIR>>/tools/lldb/source/Plugins/ExpressionParser/Clang/IRForTarget.h:14,
                 from /<<PKGBUILDDIR>>/tools/lldb/source/Plugins/ExpressionParser/Clang/IRForTarget.cpp:10:
/usr/include/c++/8/bits/stl_pair.h:198:12: note: 'struct std::pair<void*, long unsigned int>' declared here
     struct pair
            ^~~~
cc1plus: warning: unrecognized command line option '-Wno-vla-extension'
cc1plus: warning: unrecognized command line option '-Wno-deprecated-register'
cc1plus: warning: unrecognized command line option '-Wno-vla-extension'
cc1plus: warning: unrecognized command line option '-Wno-deprecated-register'
cc1plus: warning: unrecognized command line option '-Wno-vla-extension'
cc1plus: warning: unrecognized command line option '-Wno-deprecated-register'
cc1plus: warning: unrecognized command line option '-Wno-vla-extension'
cc1plus: warning: unrecognized command line option '-Wno-deprecated-register'
[ 40%] Linking CXX static library ../../../../../../lib/liblldbPluginExpressionParserClang.a
cd /<<PKGBUILDDIR>>/build-llvm/tools/lldb/source/Plugins/ExpressionParser/Clang && /usr/bin/cmake -P CMakeFiles/lldbPluginExpressionParserClang.dir/cmake_clean_target.cmake
cd /<<PKGBUILDDIR>>/build-llvm/tools/lldb/source/Plugins/ExpressionParser/Clang && /usr/bin/cmake -E cmake_link_script CMakeFiles/lldbPluginExpressionParserClang.dir/link.txt --verbose=1
/usr/bin/ar qc ../../../../../../lib/liblldbPluginExpressionParserClang.a  CMakeFiles/lldbPluginExpressionParserClang.dir/ASTDumper.cpp.o CMakeFiles/lldbPluginExpressionParserClang.dir/ASTResultSynthesizer.cpp.o CMakeFiles/lldbPluginExpressionParserClang.dir/ASTStructExtractor.cpp.o CMakeFiles/lldbPluginExpressionParserClang.dir/ClangASTSource.cpp.o CMakeFiles/lldbPluginExpressionParserClang.dir/ClangExpressionDeclMap.cpp.o CMakeFiles/lldbPluginExpressionParserClang.dir/ClangExpressionParser.cpp.o CMakeFiles/lldbPluginExpressionParserClang.dir/ClangExpressionVariable.cpp.o CMakeFiles/lldbPluginExpressionParserClang.dir/ClangFunctionCaller.cpp.o CMakeFiles/lldbPluginExpressionParserClang.dir/ClangModulesDeclVendor.cpp.o CMakeFiles/lldbPluginExpressionParserClang.dir/ClangPersistentVariables.cpp.o CMakeFiles/lldbPluginExpressionParserClang.dir/ClangUserExpression.cpp.o CMakeFiles/lldbPluginExpressionParserClang.dir/ClangUtilityFunction.cpp.o CMakeFiles/lldbPluginExpressionParserClang.dir/IRForTarget.cpp.o
/usr/bin/ranlib ../../../../../../lib/liblldbPluginExpressionParserClang.a
make[4]: Leaving directory '/<<PKGBUILDDIR>>/build-llvm'
[ 40%] Built target lldbPluginExpressionParserClang
make[3]: Leaving directory '/<<PKGBUILDDIR>>/build-llvm'
make[2]: *** [Makefile:155: all] Error 2
make[2]: Leaving directory '/<<PKGBUILDDIR>>/build-llvm'
make[1]: *** [debian/rules:298: override_dh_auto_build] Error 2
make[1]: Leaving directory '/<<PKGBUILDDIR>>'
make: *** [debian/rules:180: build-arch] Error 2
dpkg-buildpackage: error: debian/rules build-arch subprocess returned exit status 2