Restore C++17 mode for Interpreter/Cling

[davidlt]

This was lost while migrating to newer LLVM/Clang stack.

Otherwise -std=c++11 is added to compilation lines overriding -std=c++1z. Thus Cling/Interpreter ends up in C++11 mode and then we get errors about std::string_view only being available in C++17.

Compiled on Fedora 26 with -Dminimal=ON -Dcxx17=ON. Note, it still fails to build near the end:

FAILED: html/G__Html.cxx lib/libHtml_rdict.pcm lib/libHtml.rootmap
cd /build/build/html && /usr/bin/cmake -E env LD_LIBRARY_PATH=/build/build/lib: ROOTIGNOREPREFIX=1 /build/build/bin/rootcling -rootbuild -f G__Html.cxx -s /build/build/lib/libHtml.so -excludePath /build/root -excludePath /build/build -rml libHtml.so -rmf /build/build/lib/libHtml.rootmap -I/build/root -I/build/root/interpreter/cling/include -I/build/build/include TClassDocOutput.h TDocDirective.h TDocInfo.h TDocOutput.h TDocParser.h THtml.h /build/root/html/inc/LinkDef.h

 *** Break *** segmentation violation

Signed-off-by: David Abdurachmanov [email protected]

[phsft-bot]

Starting build on gcc49/centos7, native/mac1012, gcc49/slc6, gcc62/slc6, native/ubuntu14 with CMake flags -Dvc=OFF -Dimt=ON -Dccache=ON

[phsft-bot]

Build failed on ubuntu14/native.
See console output.

[phsft-bot]

Build failed on centos7/gcc49.
See console output.

Failing tests:

• projectroot.roottest.root.tree.array.roottest_root_tree_array_make
• projectroot.roottest.root.tree.treeproblem.roottest_root_tree_treeproblem_make

[phsft-bot]

Build failed on slc6/gcc62.
See console output.

Failing tests:

• projectroot.roottest.root.tree.array.roottest_root_tree_array_make
• projectroot.roottest.root.tree.treeproblem.roottest_root_tree_treeproblem_make

[phsft-bot]

Build failed on slc6/gcc49.
See console output.

Failing tests:

• projectroot.roottest.root.tree.array.roottest_root_tree_array_make
• projectroot.roottest.root.tree.treeproblem.roottest_root_tree_treeproblem_make

[vgvassilev]

It seems this didn't end up in our llvm.git as it probably won't now and next time it would be wiped away again. I will submit it for upstreaming...

[phsft-bot]

Build failed on mac1012/native.
See console output.

Failing tests:

• projectroot.roottest.python.stl.roottest_python_stl_stl
• projectroot.roottest.root.tree.treeproblem.roottest_root_tree_treeproblem_make
• projectroot.roottest.root.tree.array.roottest_root_tree_array_make

[davidlt]

Here are more details on where segfault happens:

Starting program: /build/davidlt/build/bin/rootcling -rootbuild -f G__Html.cxx -s /build/davidlt/build/lib/libHtml.so -excludePath /build/davidlt/root -excludePath /build/davidlt/build -rml libHtml.so -rmf /build/davidlt/build/lib/libHtml.rootmap -I/build/davidlt/root -I/build/davidlt/root/interpreter/cling/include -I/build/davidlt/build/include TClassDocOutput.h TDocDirective.h TDocInfo.h TDocOutput.h TDocParser.h THtml.h /build/davidlt/root/html/inc/LinkDef.h
Missing separate debuginfos, use: dnf debuginfo-install glibc-2.25-5.fc26.x86_64
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
Detaching after fork from child process 62.

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff103ee92 in clang::Redeclarable<clang::RedeclarableTemplateDecl>::getFirstDecl (this=0x38) at /build/davidlt/root/interpreter/llvm/src/tools/clang/include/clang/AST/Redeclarable.h:159
159	  const decl_type *getFirstDecl() const { return First; }
Missing separate debuginfos, use: dnf debuginfo-install libgcc-7.1.1-2.fc26.x86_64 libstdc++-7.1.1-2.fc26.x86_64 sssd-client-1.15.2-5.fc26.x86_64 zlib-1.2.11-2.fc26.x86_64
(gdb) bt
#0  0x00007ffff103ee92 in clang::Redeclarable<clang::RedeclarableTemplateDecl>::getFirstDecl (this=0x38) at /build/davidlt/root/interpreter/llvm/src/tools/clang/include/clang/AST/Redeclarable.h:159
#1  0x00007ffff103bfa6 in clang::RedeclarableTemplateDecl::getCanonicalDecl (this=0x0) at /build/davidlt/root/interpreter/llvm/src/tools/clang/include/clang/AST/DeclTemplate.h:828
#2  0x00007ffff103c1b8 in clang::ClassTemplateDecl::getCanonicalDecl (this=0x0) at /build/davidlt/root/interpreter/llvm/src/tools/clang/include/clang/AST/DeclTemplate.h:2126
#3  0x00007ffff10319a4 in ROOT::TMetaUtils::ReSubstTemplateArg (input=..., instance=0x3044f50) at /build/davidlt/root/core/clingutils/src/TClingUtils.cxx:4587
#4  0x00007ffff117457e in TCling::InspectMembers (this=0x68dcc0, insp=..., obj=0x0, cl=0x3084990, isTransient=true) at /build/davidlt/root/core/metacling/src/TCling.cxx:2237
#5  0x00007fffefe107d6 in TClass::CallShowMembers (this=0x3084990, obj=0x0, insp=..., isTransient=true) at /build/davidlt/root/core/meta/src/TClass.cxx:2137
#6  0x00007fffefe0fd69 in TClass::BuildRealData (this=0x3084990, pointer=0x0, isTransient=true) at /build/davidlt/root/core/meta/src/TClass.cxx:1992
#7  0x00007fffefe09ffe in TBuildRealData::Inspect (this=0x7fffffffbba0, cl=0x1a934a0, pname=0x30743f0 "", mname=0x7fffffffb800 "fMethodCounts", add=0x138, isTransient=true) at /build/davidlt/root/core/meta/src/TClass.cxx:851
#8  0x00007ffff1174e44 in TCling::InspectMembers (this=0x68dcc0, insp=..., obj=0x0, cl=0x1a934a0, isTransient=true) at /build/davidlt/root/core/metacling/src/TCling.cxx:2362
#9  0x00007fffefe107d6 in TClass::CallShowMembers (this=0x1a934a0, obj=0x0, insp=..., isTransient=true) at /build/davidlt/root/core/meta/src/TClass.cxx:2137
#10 0x00007fffefe0fd69 in TClass::BuildRealData (this=0x1a934a0, pointer=0x0, isTransient=true) at /build/davidlt/root/core/meta/src/TClass.cxx:1992
#11 0x00007fffefe431b4 in TProtoClass::TProtoClass (this=0x305f4f0, cl=0x1a934a0) at /build/davidlt/root/core/meta/src/TProtoClass.cxx:67
#12 0x00007ffff7b44c50 in CloseStreamerInfoROOTFile (writeEmptyRootPCM=false) at /build/davidlt/root/io/rootpcm/src/rootclingIO.cxx:197
#13 0x00007ffff1147e1e in FinalizeStreamerInfoWriting (interp=..., writeEmptyRootPCM=false) at /build/davidlt/root/core/dictgen/src/rootcling_impl.cxx:2919
#14 0x00007ffff11486a2 in GenerateFullDict (dictStream=..., interp=..., scan=..., ctorTypes=std::__cxx11::list = {...}, isSplit=false, isGenreflex=false, writeEmptyRootPCM=false) at /build/davidlt/root/core/dictgen/src/rootcling_impl.cxx:3050
#15 0x00007ffff115295f in RootClingMain (argc=24, argv=0x7fffffffe3c8, isDeep=false, isGenreflex=false) at /build/davidlt/root/core/dictgen/src/rootcling_impl.cxx:4723
#16 0x00007ffff1157fba in ROOT_rootcling_Driver (argc=24, argv=0x7fffffffe3c8, config=...) at /build/davidlt/root/core/dictgen/src/rootcling_impl.cxx:5910
#17 0x0000000000400bbc in main (argc=24, argv=0x7fffffffe3c8) at /build/davidlt/root/main/src/rootcling.cxx:46

clang::Redeclarable has a bad address.

[vgvassilev]

It seems that ROOT::TMetaUtils::ReSubstTemplateArg couldn't find the ClassTemplateDecl it expected.

Could we have a reduced example of the code that's being passed and mishandled by TClingUtils.cxx:4587

[davidlt]

Ah, yeah, I didn't check upper frames. Probably TSTdecl->getSpecializedTemplate() produced nullptr.

[vgvassilev]

As you said the TSTdecl has no specializations. It could be that it was not seen by the interpreter...
Was it expecting some llvm::entity? I.e. On the working build what did it return?

[Axel-Naumann]

@pcanal needs to have a look here...

[vgvassilev]

And that's http://llvm.org/viewvc/llvm-project?revision=305123&view=revision.

[davidlt]

Here is JIRA ticket for segfault: https://sft.its.cern.ch/jira/browse/ROOT-8825