Description
Problem
Debugging in rust-gdb with a shared object library does not activate pretty-printers supplied by rustup.
Running cargo build with crate-type of bin or lib results in a .debug_gdb_scripts section on the target or library, allowing rust-gdb to auto-load the Python pretty printers dynamically during debugging. The pretty printers are great!
rust/compiler/rustc_codegen_llvm/src/debuginfo/gdb.rs
Lines 39 to 40 in 91a0600
However, for crate-type of cdylib, the .debug_gdb_scripts section is not written. This results in a lack of pretty printing in rust-gdb, and makes it more challenging to use rust-gdb to best effect. I'm seeing this when working with Python bindings of Rust code with pyo3. Is there a reason cdylib did not receive this pretty-printer support?
Workaround
I've confirmed that manually adding the .debug_gdb_scripts section to a .so library generated with crate-type=cdylib activates the pretty printers. I did noticed some Python exceptions in the pretty printers, but have not investigated further.
$ objcopy --add-section .debug_gdb_scripts=<(echo -ne "\x01gdb_load_rust_pretty_printers.py\0") ./libmytest_lib.so
$ objdump -sj .debug_gdb_scripts libmytest_lib.so
libmytest_lib.so: file format elf64-x86-64
Contents of section .debug_gdb_scripts:
0000 01676462 5f6c6f61 645f7275 73745f70 .gdb_load_rust_p
0010 72657474 795f7072 696e7465 72732e70 retty_printers.p
0020 7900 y. Version information
rustc 1.60.0 (7737e0b 2022-04-04)
cargo 1.60.0 (d1fd9fe 2022-03-01)