From cae15db74999edb96dd9f5bbd4d55849391dd92b Mon Sep 17 00:00:00 2001 From: David Tolnay Date: Sat, 9 Jul 2016 00:20:00 -0700 Subject: perf symbols: Add Rust demangling Rust demangling is another step after bfd demangling. Add a diagnosis to identify mangled Rust symbols based on the hash that the Rust mangler appends as the last path component, as well as other characteristics. Add a demangler to reconstruct the original symbol. Committer notes: How I tested it: Enabled COPR on Fedora 24 and then installed the 'rust-binary' package, with it: $ cat src/main.rs fn main() { println!("Hello, world!"); } $ cat Cargo.toml [package] name = "hello_world" version = "0.0.1" authors = [ "Arnaldo Carvalho de Melo " ] $ perf record cargo bench Compiling hello_world v0.0.1 (file:///home/acme/projects/hello_world) Running target/release/hello_world-d4b9dab4b2a47d75 running 0 tests test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.096 MB perf.data (1457 samples) ] $ Before this patch: $ perf report --stdio --dsos librbml-e8edd0fd.so # dso: librbml-e8edd0fd.so # # Total Lost Samples: 0 # # Samples: 1K of event 'cycles:u' # Event count (approx.): 979599126 # # Overhead Command Symbol # ........ ....... ............................................................................................................. # 1.78% rustc [.] rbml::reader::maybe_get_doc::hb9d387df6024b15b 1.50% rustc [.] _$LT$reader..DocsIterator$LT$$u27$a$GT$$u20$as$u20$std..iter..Iterator$GT$::next::hd9af9e60d79a35c8 1.20% rustc [.] rbml::reader::doc_at::hc88107fba445af31 0.46% rustc [.] _$LT$reader..TaggedDocsIterator$LT$$u27$a$GT$$u20$as$u20$std..iter..Iterator$GT$::next::h0cb40e696e4bb489 0.35% rustc [.] rbml::reader::Decoder::_next_int::h66eef7825a398bc3 0.29% rustc [.] rbml::reader::Decoder::_next_sub::h8e5266005580b836 0.15% rustc [.] rbml::reader::get_doc::h094521c645459139 0.14% rustc [.] _$LT$reader..Decoder$LT$$u27$doc$GT$$u20$as$u20$serialize..Decoder$GT$::read_u32::h0acea2fff9669327 0.07% rustc [.] rbml::reader::Decoder::next_doc::h6714d469c9dfaf91 0.07% rustc [.] _ZN4rbml6reader10doc_as_u6417h930b740aa94f1d3aE@plt 0.06% rustc [.] _fini $ After: $ perf report --stdio --dsos librbml-e8edd0fd.so # dso: librbml-e8edd0fd.so # # Total Lost Samples: 0 # # Samples: 1K of event 'cycles:u' # Event count (approx.): 979599126 # # Overhead Command Symbol # ........ ....... ................................................................. # 1.78% rustc [.] rbml::reader::maybe_get_doc 1.50% rustc [.] as std::iter::Iterator>::next 1.20% rustc [.] rbml::reader::doc_at 0.46% rustc [.] as std::iter::Iterator>::next 0.35% rustc [.] rbml::reader::Decoder::_next_int 0.29% rustc [.] rbml::reader::Decoder::_next_sub 0.15% rustc [.] rbml::reader::get_doc 0.14% rustc [.] as serialize::Decoder>::read_u32 0.07% rustc [.] rbml::reader::Decoder::next_doc 0.07% rustc [.] _ZN4rbml6reader10doc_as_u6417h930b740aa94f1d3aE@plt 0.06% rustc [.] _fini $ Signed-off-by: David Tolnay Tested-by: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/5780B7FA.3030602@gmail.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/symbol-elf.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'tools/perf/util/symbol-elf.c') diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c index cebf98ec27bc..a34321e9b44d 100644 --- a/tools/perf/util/symbol-elf.c +++ b/tools/perf/util/symbol-elf.c @@ -7,6 +7,7 @@ #include "symbol.h" #include "demangle-java.h" +#include "demangle-rust.h" #include "machine.h" #include "vdso.h" #include @@ -1081,6 +1082,13 @@ new_symbol: demangled = bfd_demangle(NULL, elf_name, demangle_flags); if (demangled == NULL) demangled = java_demangle_sym(elf_name, JAVA_DEMANGLE_NORET); + else if (rust_is_mangled(demangled)) + /* + * Input to Rust demangling is the BFD-demangled + * name which it Rust-demangles in place. + */ + rust_demangle_sym(demangled); + if (demangled != NULL) elf_name = demangled; } -- cgit v1.2.3