使用clang编译时无法查看std :: string

g ++(GCC)5.2.0

clang版本3.7.1(标签/ RELEASE_371/final)

GNU gdb(GDB)7.12

由于某种原因,当使用clang编译时,Gdb无法找到std :: string的定义.我有自定义编译和构建gcc和clang,因为Centos 6.5附带了旧版本的gcc.

示例代码

#include 

int main()
{
    std::string s("This is a string");

    return 0;
}

用g ++编译和调试 - 工作得很好

[~]$ g++ -ggdb3 -std=c++14 stl.cpp 
[~]$ gdb a.out
GNU gdb (GDB) 7.12
Reading symbols from a.out...done.
(gdb) break main
Breakpoint 1 at 0x400841: file stl.cpp, line 5.
(gdb) r
Starting program: /home/vagrant/a.out 

Breakpoint 1, main () at stl.cpp:5
5       std::string s("This is a string");
(gdb) n
7       return 0;
(gdb) p s
$1 = {static npos = , 
  _M_dataplus = {> = {<__gnu_cxx::new_allocator> = {}, }, _M_p = 0x612c20 "This is a string"}, _M_string_length = 16, {
    _M_local_buf = "\020\000\000\000\000\000\000\000\300\b@\000\000\000\000", _M_allocated_capacity = 16}}
(gdb) 

检查它是否与我的rpm构建版本的libstdc ++链接,而不是系统

[~]$ ldd a.out
    linux-vdso.so.1 =>  (0x00007ffd709e0000)
    libstdc++.so.6 => /opt/spotx-gcc/lib64/libstdc++.so.6 (0x00007f29318fa000)
    libm.so.6 => /lib64/libm.so.6 (0x00007f2931676000)
    libgcc_s.so.1 => /opt/spotx-gcc/lib64/libgcc_s.so.1 (0x00007f293145f000)
    libc.so.6 => /lib64/libc.so.6 (0x00007f29310cb000)
    /lib64/ld-linux-x86-64.so.2 (0x00007f2931c93000)

[~]$ objdump -T -C a.out
a.out:     file format elf64-x86-64
DYNAMIC SYMBOL TABLE:
0000000000000000  w   D  *UND*  0000000000000000              __gmon_start__
0000000000000000  w   D  *UND*  0000000000000000              _Jv_RegisterClasses
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 __libc_start_main
0000000000000000  w   D  *UND*  0000000000000000              _ITM_deregisterTMCloneTable
0000000000000000  w   D  *UND*  0000000000000000              _ITM_registerTMCloneTable
0000000000000000      DF *UND*  0000000000000000  GLIBCXX_3.4.21 std::__cxx11::basic_string, std::allocator >::~basic_string()
0000000000000000      DF *UND*  0000000000000000  GLIBCXX_3.4 std::allocator::~allocator()
0000000000000000      DF *UND*  0000000000000000  GLIBCXX_3.4.21 std::__cxx11::basic_string, std::allocator >::basic_string(char const*, std::allocator const&)
0000000000000000      DF *UND*  0000000000000000  GLIBCXX_3.4 std::allocator::allocator()
0000000000000000      DF *UND*  0000000000000000  GCC_3.0     _Unwind_Resume
0000000000400700      DF *UND*  0000000000000000  CXXABI_1.3  __gxx_personality_v0

如果我用clang尝试相同的话,现在看起来都很好

[~]$ clang++ -std=c++14 -g stl.cpp
[~]$ gdb a.out
GNU gdb (GDB) 7.12
Reading symbols from a.out...done.
(gdb) break  main
Breakpoint 1 at 0x400853: file stl.cpp, line 5.
(gdb) r
Starting program: /home/vagrant/a.out 

Breakpoint 1, main () at stl.cpp:5
5       std::string s("This is a string");
(gdb) n
7       return 0;
(gdb) p s
$1 = 
(gdb) 

现在我得到了一个不完整的类型 - 但是正在使用相同的库

[~]$ ldd a.out
    linux-vdso.so.1 =>  (0x00007fff5352d000)
    libstdc++.so.6 => /opt/spotx-gcc/lib64/libstdc++.so.6 (0x00007f76b4023000)
    libm.so.6 => /lib64/libm.so.6 (0x00007f76b3d9f000)
    libgcc_s.so.1 => /opt/spotx-gcc/lib64/libgcc_s.so.1 (0x00007f76b3b88000)
    libc.so.6 => /lib64/libc.so.6 (0x00007f76b37f4000)
    /lib64/ld-linux-x86-64.so.2 (0x00007f76b43bc000)


[~]$ objdump -T -C a.out
a.out:     file format elf64-x86-64
DYNAMIC SYMBOL TABLE:
0000000000000000  w   D  *UND*  0000000000000000              __gmon_start__
0000000000000000  w   D  *UND*  0000000000000000              _Jv_RegisterClasses
0000000000000000      DF *UND*  0000000000000000  GLIBC_2.2.5 __libc_start_main
0000000000000000  w   D  *UND*  0000000000000000              _ITM_deregisterTMCloneTable
0000000000000000  w   D  *UND*  0000000000000000              _ITM_registerTMCloneTable
0000000000000000      DF *UND*  0000000000000000  GLIBCXX_3.4.21 std::__cxx11::basic_string, std::allocator >::~basic_string()
0000000000000000      DF *UND*  0000000000000000  GLIBCXX_3.4 std::allocator::~allocator()
0000000000000000      DF *UND*  0000000000000000  GLIBCXX_3.4.21 std::__cxx11::basic_string, std::allocator >::basic_string(char const*, std::allocator const&)
0000000000000000      DF *UND*  0000000000000000  GLIBCXX_3.4 std::allocator::allocator()
0000000000000000      DF *UND*  0000000000000000  GCC_3.0     _Unwind_Resume
0000000000400700      DF *UND*  0000000000000000  CXXABI_1.3  __gxx_personality_v0

有没有人有任何关于在哪里寻找或我错过的东西的建议.两个编译器在构建时都是自举的 - 一切看起来都很好 - 它似乎是std :: string在使用clang时没有定义.

正如ks1322所提到的,这是因为clang决定不为libstc ++发出调试信息.

你可以通过提供以下标志强制clang这样做: -D_GLIBCXX_DEBUG

我只提供调试版本的标志,但如果debug是默认值,而版本版本是特殊目标,则应删除它:

release: CXXFLAGS := $(filter-out -D_GLIBCXX_DEBUG,$(CXXFLAGS)) -O2

这为我解决了同样的问题.