[Clang] -finstrument-functions does not insert '__cyg_profile_func_exit' when using throw expression in c++

[ggstone0523]

'-finstrument-functions' option does not insert '__cyg_profile_func_exit' to function that using throw expression.

code :

#include <stdexcept>

void A()
{
        throw std::runtime_error("!");
};

int main()
{
        try {
                A();
        } catch( ... ) {
        }

        return 0;
}

run

clang++ ./test.cpp -finstrument-functions

result of disassemble using objdump

...
00000000000011a0 <_Z1Av>:
    11a0:       55                      push   %rbp
    11a1:       48 89 e5                mov    %rsp,%rbp
    11a4:       48 83 ec 20             sub    $0x20,%rsp
    11a8:       48 8b 75 08             mov    0x8(%rbp),%rsi
    11ac:       48 8d 3d ed ff ff ff    lea    -0x13(%rip),%rdi        # 11a0 <_Z1Av>
    11b3:       e8 78 fe ff ff          call   1030 <__cyg_profile_func_enter@plt>
    11b8:       bf 10 00 00 00          mov    $0x10,%edi
    11bd:       e8 8e fe ff ff          call   1050 <__cxa_allocate_exception@plt>
    11c2:       48 89 c7                mov    %rax,%rdi
    11c5:       48 89 f8                mov    %rdi,%rax
    11c8:       48 89 45 e8             mov    %rax,-0x18(%rbp)
    11cc:       48 8d 35 31 0e 00 00    lea    0xe31(%rip),%rsi        # 2004 <_IO_stdin_used+0x4>
    11d3:       e8 68 fe ff ff          call   1040 <_ZNSt13runtime_errorC1EPKc@plt>
    11d8:       e9 00 00 00 00          jmp    11dd <_Z1Av+0x3d>
    11dd:       48 8b 7d e8             mov    -0x18(%rbp),%rdi
    11e1:       48 8b 35 10 2e 00 00    mov    0x2e10(%rip),%rsi        # 3ff8 <_ZTISt13runtime_error@GLIBCXX_3.4>
    11e8:       48 8b 15 e9 2d 00 00    mov    0x2de9(%rip),%rdx        # 3fd8 <_ZNSt13runtime_errorD1Ev@GLIBCXX_3.4>
    11ef:       e8 8c fe ff ff          call   1080 <__cxa_throw@plt>
    11f4:       48 8b 7d e8             mov    -0x18(%rbp),%rdi
    11f8:       48 89 c1                mov    %rax,%rcx
    11fb:       89 d0                   mov    %edx,%eax
    11fd:       48 89 4d f8             mov    %rcx,-0x8(%rbp)
    1201:       89 45 f4                mov    %eax,-0xc(%rbp)
    1204:       e8 57 fe ff ff          call   1060 <__cxa_free_exception@plt>
    1209:       48 8b 7d f8             mov    -0x8(%rbp),%rdi
    120d:       e8 7e fe ff ff          call   1090 <_Unwind_Resume@plt>
    1212:       66 66 66 66 66 2e 0f    data16 data16 data16 data16 cs nopw 0x0(%rax,%rax,1)
    1219:       1f 84 00 00 00 00 00
...

[pinskia]

Just FYI, the behavior changed in GCC 4.0 to start inserting __cyg_profile_func_exit on the final path when -finstrument-functions was reimplemented to the tree level from handling it on the expand phase. See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=2200 also.

[llvmbot]

@llvm/issue-subscribers-clang-codegen

Author: Choi Yusun (ggstone0523)

'-finstrument-functions' option does not insert '__cyg_profile_func_exit' to function that using throw expression.

code :

#include <stdexcept>

void A()
{
        throw std::runtime_error("!");
};

int main()
{
        try {
                A();
        } catch( ... ) {
        }

        return 0;
}

run

clang++ ./test.cpp -finstrument-functions

result of disassemble using objdump

...
00000000000011a0 <_Z1Av>:
    11a0:       55                      push   %rbp
    11a1:       48 89 e5                mov    %rsp,%rbp
    11a4:       48 83 ec 20             sub    $0x20,%rsp
    11a8:       48 8b 75 08             mov    0x8(%rbp),%rsi
    11ac:       48 8d 3d ed ff ff ff    lea    -0x13(%rip),%rdi        # 11a0 <_Z1Av>
    11b3:       e8 78 fe ff ff          call   1030 &lt;__cyg_profile_func_enter@<!-- -->plt&gt;
    11b8:       bf 10 00 00 00          mov    $0x10,%edi
    11bd:       e8 8e fe ff ff          call   1050 &lt;__cxa_allocate_exception@<!-- -->plt&gt;
    11c2:       48 89 c7                mov    %rax,%rdi
    11c5:       48 89 f8                mov    %rdi,%rax
    11c8:       48 89 45 e8             mov    %rax,-0x18(%rbp)
    11cc:       48 8d 35 31 0e 00 00    lea    0xe31(%rip),%rsi        # 2004 &lt;_IO_stdin_used+0x4&gt;
    11d3:       e8 68 fe ff ff          call   1040 &lt;_ZNSt13runtime_errorC1EPKc@<!-- -->plt&gt;
    11d8:       e9 00 00 00 00          jmp    11dd &lt;_Z1Av+0x3d&gt;
    11dd:       48 8b 7d e8             mov    -0x18(%rbp),%rdi
    11e1:       48 8b 35 10 2e 00 00    mov    0x2e10(%rip),%rsi        # 3ff8 &lt;_ZTISt13runtime_error@<!-- -->GLIBCXX_3.4&gt;
    11e8:       48 8b 15 e9 2d 00 00    mov    0x2de9(%rip),%rdx        # 3fd8 &lt;_ZNSt13runtime_errorD1Ev@<!-- -->GLIBCXX_3.4&gt;
    11ef:       e8 8c fe ff ff          call   1080 &lt;__cxa_throw@<!-- -->plt&gt;
    11f4:       48 8b 7d e8             mov    -0x18(%rbp),%rdi
    11f8:       48 89 c1                mov    %rax,%rcx
    11fb:       89 d0                   mov    %edx,%eax
    11fd:       48 89 4d f8             mov    %rcx,-0x8(%rbp)
    1201:       89 45 f4                mov    %eax,-0xc(%rbp)
    1204:       e8 57 fe ff ff          call   1060 &lt;__cxa_free_exception@<!-- -->plt&gt;
    1209:       48 8b 7d f8             mov    -0x8(%rbp),%rdi
    120d:       e8 7e fe ff ff          call   1090 &lt;_Unwind_Resume@<!-- -->plt&gt;
    1212:       66 66 66 66 66 2e 0f    data16 data16 data16 data16 cs nopw 0x0(%rax,%rax,1)
    1219:       1f 84 00 00 00 00 00
...