c++ - Clang 构建错误

Question

我正在尝试在 Ubuntu 16.04 上构建 clang 主干，但无论我尝试什么，我都会遇到构建错误。首先，我针对 gcc 5.4 构建了 llvm/clang/libc++/libc++abi，这工作正常。现在我正在尝试使用我刚刚构建的 clang 来重建 llvm/clang/libc++/libc++abi。此操作失败并显示以下错误消息:

    [162/4396] Linking CXX executable bin/llvm-tblgen FAILED: 
: && /usr/local/bin/clang++ -stdlib=libc++ 
-fPIC
 -fvisibility-inlines-hidden -Wall -W -Wno-unused-parameter 
-Wwrite-strings -Wcast-qual -Wmissing-field-initializers 
-pedantic -Wno-long-long -Wcovered-switch-default 
-Wnon-virtual-dtor -Wdelete-non-virtual-dtor 
-Werror=date-time -std=c++11 -fcolor-diagnostics 
-ffunction-sections -fdata-sections -O3 -DNDEBUG  
-lc++ -lc++abi -Wl,-allow-shlib-undefined    
-Wl,-O3 -Wl,--gc-sections 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/AsmMatcherEmitter.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/AsmWriterEmitter.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/AsmWriterInst.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/Attributes.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/CallingConvEmitter.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/CodeEmitterGen.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/CodeGenDAGPatterns.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/CodeGenInstruction.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/CodeGenMapTable.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/CodeGenRegisters.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/CodeGenSchedule.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/CodeGenTarget.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/DAGISelEmitter.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/DAGISelMatcherEmitter.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/DAGISelMatcherGen.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/DAGISelMatcherOpt.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/DAGISelMatcher.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/DFAPacketizerEmitter.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/DisassemblerEmitter.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/FastISelEmitter.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/FixedLenDecoderEmitter.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/InstrInfoEmitter.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/IntrinsicEmitter.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/OptParserEmitter.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/PseudoLoweringEmitter.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/RegisterInfoEmitter.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/SearchableTableEmitter.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/SubtargetEmitter.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/TableGen.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/X86DisassemblerTables.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/X86ModRMFilters.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/X86RecognizableInstr.cpp.o 
utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/CTagsEmitter.cpp.o  
-o bin/llvm-tblgen  
lib/libLLVMSupport.a 
lib/libLLVMTableGen.a 
-lpthread 
lib/libLLVMSupport.a 
-lrt 
-ldl 
-ltinfo 
-lpthread 
-lz 
-lm 
lib/libLLVMDemangle.a 
-Wl,-rpath,"\$ORIGIN/../lib" && 
: utils/TableGen/CMakeFiles/obj.llvm-tblgen.dir/DFAPacketizerEmitter.cpp.o: In function `(anonymous namespace)::DFAPacketizerEmitter::run(llvm::raw_ostream&)': /home/mehrlich/Code/llvm/llvm/utils/TableGen/DFAPacketizerEmitter.cpp:(.text._ZN12_GLOBAL__N_120DFAPacketizerEmitter3runERN4llvm11raw_ostreamE+0x253f): undefined reference to `std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>::~basic_string()' clang-4.0: error: linker command failed with exit code 1 (use -v to see invocation) [162/4396] Building CXX object lib/MC/CMakeFiles/LLVMMC.dir/MCContext.cpp.o ninja: build stopped: subcommand failed.

相关错误是 undefined symbol :

In function (anonymous namespace)::DFAPacketizerEmitter::run(llvm::raw_ostream&)': /home/mehrlich/Code/llvm/llvm/utils/TableGen/DFAPacketizerEmitter.cpp:(.text._ZN12_GLOBAL__N_120DFAPacketizerEmitter3runERN4llvm11raw_ostreamE+0x253f): undefined reference to std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>::~basic_string()'

大概这是出于以下两个原因之一:

1。 Clang 正在使用 libstdc++ header :

我们可以从失败的命令中看出，clang++ 正确地选择了 -stdlib=libc++ 开关。正在运行 % clang++ --stdlib=libc++ -E -x c++ - -v < /dev/null使用此选项检查默认包含路径给出

clang version 4.0.0 (trunk 281213) Target: x86_64-unknown-linux-gnu Thread model: posix InstalledDir: /usr/local/bin Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/5 Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/5.4.0 Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/6 Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/6.0.0 Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.9 Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.9.3 Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5 Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5.4.0 Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6 Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6.0.0 Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5.4.0 Candidate multilib: .;@m64 Selected multilib: .;@m64 Found CUDA installation: /usr/local/cuda, version 7.5  "/usr/local/bin/clang-4.0" -cc1 -triple x86_64-unknown-linux-gnu -E -disable-free -disable-llvm-verifier
-discard-value-names -main-file-name - -mrelocation-model static -mthread-model posix -mdisable-fp-elim -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -v -dwarf-column-info -debugger-tuning=gdb -resource-dir /usr/local/bin/../lib/clang/4.0.0 -internal-isystem /usr/local/bin/../include/c++/v1 -internal-isystem /usr/local/include
-internal-isystem /usr/local/bin/../lib/clang/4.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -fdeprecated-macro -fdebug-compilation-dir /home/mehrlich/Code/llvm/build -ferror-limit 19 -fmessage-length 343
-fobjc-runtime=gcc -fcxx-exceptions -fexceptions -fdiagnostics-show-option -fcolor-diagnostics -o - -x c++ - clang -cc1 version 4.0.0 based upon LLVM 4.0.0svn default target x86_64-unknown-linux-gnu ignoring nonexistent directory "/include"
#include "..." search starts here:
#include <...> search starts here:  /usr/local/bin/../include/c++/v1  /usr/local/include  /usr/local/bin/../lib/clang/4.0.0/include  /usr/include/x86_64-linux-gnu  /usr/include End of search list.
# 1 "<stdin>"
# 1 "<built-in>" 1
# 1 "<built-in>" 3
# 328 "<built-in>" 3
# 1 "<command line>" 1
# 1 "<built-in>" 2
# 1 "<stdin>" 2

第一个标题搜索路径#include <...> search starts here: /usr/local/bin/../include/c++/v1是 libc++ header 的正确位置。所以我非常怀疑是这个

2。 Clang 没有链接到 libc++

添加选项 -lc++ -lc++abi到 CMAKE_EXE_LINKER_FLAGS、CMAKE_SHARED_LINKER_FLAGS、CMAKE_MODULE_LINKER_FLAGS 和 CMAKE_STATIC_LINKER_FLAGS 给出以下错误:

[65/4396] Linking CXX static library lib/libLLVMDemangle.a
FAILED: : && /usr/bin/cmake -E remove lib/libLLVMDemangle.a && /usr/bin/ar qc lib/libLLVMDemangle.a -lc++ -lc++abi lib/Demangle/CMakeFiles/LLVMDemangle.dir/ItaniumDemangle.cpp.o && /usr/bin/ranlib lib/libLLVMDemangle.a && :
/usr/bin/ar: invalid option -- '+'
Usage: /usr/bin/ar [emulation options] [-]{dmpqrstx}[abcDfilMNoPsSTuvV] [--plugin <name>] [member-name] [count] archive-file file...
       /usr/bin/ar -M [<mri-script]
 commands:
  d            - delete file(s) from the archive
  m[ab]        - move file(s) in the archive
  p            - print file(s) found in the archive
  q[f]         - quick append file(s) to the archive
  r[ab][f][u]  - replace existing or insert new file(s) into the archive
  s            - act as ranlib
  t            - display contents of archive
  x[o]         - extract file(s) from the archive
 command specific modifiers:
  [a]          - put file(s) after [member-name]
  [b]          - put file(s) before [member-name] (same as [i])
  [D]          - use zero for timestamps and uids/gids (default)
  [U]          - use actual timestamps and uids/gids
  [N]          - use instance [count] of name
  [f]          - truncate inserted file names
  [P]          - use full path names when matching
  [o]          - preserve original dates
  [u]          - only replace files that are newer than current archive contents
 generic modifiers:
  [c]          - do not warn if the library had to be created
  [s]          - create an archive index (cf. ranlib)
  [S]          - do not build a symbol table
  [T]          - make a thin archive
  [v]          - be verbose
  [V]          - display the version number
  @<file>      - read options from <file>
  --target=BFDNAME - specify the target object format as BFDNAME
 optional:
  --plugin <p> - load the specified plugin
 emulation options: 
  No emulation specific options
/usr/bin/ar: supported targets: elf64-x86-64 elf32-i386 elf32-iamcu elf32-x86-64 a.out-i386-linux pei-i386 pei-x86-64 elf64-l1om elf64-k1om elf64-little elf64-big elf32-little elf32-big pe-x86-64 pe-bigobj-x86-64 pe-i386 plugin srec symbolsrec verilog tekhex binary ihex

为此我们可以看到，链接器选项正在传递给 /usr/bin/ar通过 cmake 静态库(这对我来说似乎是错误的事情，但我不是构建过程的专家所以我可能是错的)。从 CMAKE_STATIC_LINKER_FLAGS 中删除这些选项会恢复到有关 undefined symbol 的原始错误消息， 因此大概是 llvm-tblgen目标是一个静态库。 llvm-tblgen绝对是一个可执行文件，不确定 CMAKE_EXE_LINKER_FLAGS 是否未应用于它 正在应用标志，这意味着我不知道为什么这不起作用......

在这一点上，我不确定这是谁的错，我的错，clang 或 cmake，但如果有人在执行此过程中有任何建议或专业知识，我将不胜感激。

更新

现在错误出现在 compiler-rt 中:

projects/compiler-rt/lib/sanitizer_common/CMakeFiles/RTSanitizerCommonLibc.x86_64.dir/sanitizer_unwind_linux_libcdep.cc.o: In function `__sanitizer::Unwind_GetIP(_Unwind_Context*)':
/home/mehrlich/Code/llvm/llvm/projects/compiler-rt/lib/sanitizer_common/sanitizer_unwind_linux_libcdep.cc:98: undefined reference to `_Unwind_GetIP'
projects/compiler-rt/lib/sanitizer_common/CMakeFiles/RTSanitizerCommonLibc.x86_64.dir/sanitizer_unwind_linux_libcdep.cc.o: In function `Unwind_GetIP':
/home/mehrlich/Code/llvm/llvm/projects/compiler-rt/lib/sanitizer_common/sanitizer_unwind_linux_libcdep.cc:98: undefined reference to `_Unwind_GetIP'
projects/compiler-rt/lib/sanitizer_common/CMakeFiles/RTSanitizerCommonLibc.x86_64.dir/sanitizer_unwind_linux_libcdep.cc.o: In function `__sanitizer::BufferedStackTrace::SlowUnwindStack(unsigned long, unsigned int)':
/home/mehrlich/Code/llvm/llvm/projects/compiler-rt/lib/sanitizer_common/sanitizer_unwind_linux_libcdep.cc:125: undefined reference to `_Unwind_Backtrace'
projects/compiler-rt/lib/sanitizer_common/CMakeFiles/RTSanitizerCommonLibc.x86_64.dir/sanitizer_unwind_linux_libcdep.cc.o: In function `SlowUnwindStack':
/home/mehrlich/Code/llvm/llvm/projects/compiler-rt/lib/sanitizer_common/sanitizer_unwind_linux_libcdep.cc:125: undefined reference to `_Unwind_Backtrace'

似乎与此相关bug

Answer 1

这是由最近 libc++ 中的一个错误引起的，该错误意外地从使用 GCC 构建的 libc++.so 版本中删除了 ~basic_string() 的定义。该错误于 9 月 9 日引入，我今天早些时候修复了它。

不幸的是，您的 libc++ 安装有问题，需要在构建 Clang 之前对其进行更新。您可以简单地在现有安装之上安装一个新的 libc++。这可能可以使用当前(错误的)构建目录中的 sudo make install-cxx 来完成。然后您可以像往常一样继续构建 Clang。

有关构建/安装 libc++ 的更多信息，请参阅 http://libcxx.llvm.org/docs/BuildingLibcxx.html .

(注意:修复 libc++ 安装不需要重建 LLVM 或 Clang。)