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Unable to view std :: string when compiling with clang

g ++ (GCC) 5.2.0

clang version 3.7.1 (tags / RELEASE_371 / final)

GNU gdb (GDB) 7.12

Gdb cannot find the definition of std :: string when compiling with clang for any reason. I have a custom compiled and built gcc and clang since Centos 6.5 comes with the old version of gcc.

Code example

#include <string>

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

    return 0;
}

Compiling with g ++ and debug - works just fine

[~]$ 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 = <optimized out>, 
  _M_dataplus = {<std::allocator<char>> = {<__gnu_cxx::new_allocator<char>> = {<No data fields>}, <No data fields>}, _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)

Make sure it is linked to my version of libstdc ++ and not the system

[~]$ 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<char, std::char_traits<char>, std::allocator<char> >::~basic_string()
0000000000000000      DF *UND*  0000000000000000  GLIBCXX_3.4 std::allocator<char>::~allocator()
0000000000000000      DF *UND*  0000000000000000  GLIBCXX_3.4.21 std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(char const*, std::allocator<char> const&)
0000000000000000      DF *UND*  0000000000000000  GLIBCXX_3.4 std::allocator<char>::allocator()
0000000000000000      DF *UND*  0000000000000000  GCC_3.0     _Unwind_Resume
0000000000400700      DF *UND*  0000000000000000  CXXABI_1.3  __gxx_personality_v0

Now everything looks good if I try the same with clang

[~]$ 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 = <incomplete type>
(gdb)

Now I get an incomplete type - but the same libraries are used

[~]$ 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<char, std::char_traits<char>, std::allocator<char> >::~basic_string()
0000000000000000      DF *UND*  0000000000000000  GLIBCXX_3.4 std::allocator<char>::~allocator()
0000000000000000      DF *UND*  0000000000000000  GLIBCXX_3.4.21 std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(char const*, std::allocator<char> const&)
0000000000000000      DF *UND*  0000000000000000  GLIBCXX_3.4 std::allocator<char>::allocator()
0000000000000000      DF *UND*  0000000000000000  GCC_3.0     _Unwind_Resume
0000000000400700      DF *UND*  0000000000000000  CXXABI_1.3  __gxx_personality_v0

- , -, . - - std::string clang.

+4
2

ks1322, , clang libst++.

clang , :   -D_GLIBCXX_DEBUG

, debug , - , :

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

.

+8

Fedora clang.

, clang std::string, , libstdc++ . . 24202:

, libstd++:

debuginfos, : dnf debuginfo-install libgcc-5.1.1-4.fc22.x86_64 libstd++ - 5.1.1-4.fc22.x86_64

Clang std::string, , libstd++ ( ); , , -, .

, libstd++?

libstdc++ dnf debuginfo-install libstdc++-6.2.1-2.fc25.x86_64 .

+2
source

Source: https://habr.com/ru/post/1667270/

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