Description
At the moment, the official std binaries are built without frame pointers: rust-lang/rust#103711. This means that libraries and apps built with freedesktop SDK's Rust have clobbered frame pointers in std functions, even when building with -C force-frame-pointers=yes. This can be verified with a command from the issue:
$ objdump -Cd src/identity | grep -E '>:$|\$0x1,%bpl' | grep -B1 bpl | head -n 50
000000000080da60 <std::panicking::default_hook>:
80dcea: 40 b5 01 mov $0x1,%bpl
--
000000000080fb30 <std::sys::unix::futex::futex_wait>:
80fbd2: 40 b5 01 mov $0x1,%bpl
--
000000000080fcc0 <std::sys::unix::os::glibc_version>:
80fdbf: 40 f6 c5 01 test $0x1,%bpl
80fdc9: 40 f6 c5 01 test $0x1,%bpl
000000000080fe00 <<std::sys::unix::os_str::Slice as core::fmt::Display>::fmt>:
80fe9d: 40 b5 01 mov $0x1,%bpl
<and so on>
Frame pointers in all functions are needed for fast profiling, and they are already enabled across the freedesktop SDK. To be able to profile Rust applications and applications depending on Rust libraries (e.g. Rust gstreamer plugins), they should also be built with frame pointers, including the standard library crates.
Until there are official binaries with frame pointers, would it be possible to rebuild the standard library crates with -C force-frame-pointers=yes for the freedesktop SDK extension?
You can verify that it worked if building an app with -C force-frame-pointers=yes produces empty output for the above command:
$ objdump -Cd src/identity | grep -E '>:$|\$0x1,%bpl' | grep -B1 bpl | head -n 50
$
cc @alatiera