https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91929
Bug ID: 91929
Summary: missing inline subroutine information in static build
using sin/cos
Product: gcc
Version: 9.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: debug
Assignee: unassigned at gcc dot gnu.org
Reporter: mail at milianw dot de
Target Milestone: ---
Hey there,
take the attached C++ code sample and compile it with `g++ -O2 -g -static` to
produce the attached binary. Sampling it with perf produces strange backtraces
even when including inline frames - it seems like the information is simply
lacking from the generated binary? See e.g.:
```
$ addr2line -i -C -f -p -e vector_static_gcc_v9.1.0 -a 418790
0x0000000000418790: __cos_fma at ??:?
$ addr2line -i -C -f -p -e vector_static_gcc_v9.1.0 -a 401572
0x0000000000401572: generate_n<std::back_insert_iterator<std::vector<double> >,
int, main()::<lambda()> > at /usr/include/c++/9.1.0/bits/stl_algo.h:4449
(inlined by) main at /.../vector.cpp:16
```
Here's a backtrace from GDB showing this odd behavior:
```
(gdb) b __cos_fma
Breakpoint 2 at 0x418790
(gdb) c
Continuing.
Breakpoint 2, 0x0000000000418790 in __cos_fma ()
(gdb) bt
#0 0x0000000000418790 in __cos_fma ()
#1 0x0000000000401573 in
std::generate_n<std::back_insert_iterator<std::vector<double> >, int,
main()::<lambda()> > (__n=100000, __gen=...,
__first=...) at /usr/include/c++/9.1.0/new:174
#2 main () at ../../../manual/clients/vector.cpp:16
```
I'm missing inline frames for the lambda and `std::cos<int>` or similar. When
replacing g++ with clang++ 8.0.1 this looks better:
```
(gdb) bt
#0 0x00000000004191d0 in __cos_fma ()
#1 0x0000000000402663 in std::cos<int> (__x=<optimized out>)
at
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/9.1.0/../../../../include/c++/9.1.0/cmath:197
#2 main::$_0::operator() (this=<optimized out>) at ./vector.cpp:14
#3 std::generate_n<std::back_insert_iterator<std::vector<double,
std::allocator<double> > >, int, main::$_0> (__first=..., __n=100000,
__gen=...) at
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/9.1.0/../../../../include/c++/9.1.0/bits/stl_algo.h:4450
#4 main () at ./vector.cpp:12
```
