llvm-project/lldb/source/Symbol
Alexander Mols 0a2d4f3f24 [lldb] Enable Rust v0 symbol demangling
Rust's v0 name mangling scheme [1] is easy to disambiguate from other
name mangling schemes because symbols always start with `_R`. The llvm
Demangle library supports demangling the Rust v0 scheme. Use it to
demangle Rust symbols.

Added unit tests that check simple symbols. Ran LLDB built with this
patch to debug some Rust programs compiled with the v0 name mangling
scheme. Confirmed symbol names were demangled as expected.

Note: enabling the new name mangling scheme requires a nightly
toolchain:

```
$ cat main.rs
fn main() {
    println!("Hello world!");
}
$ $(rustup which --toolchain nightly rustc) -Z symbol-mangling-version=v0 main.rs -g
$ /home/asm/hacking/llvm/build/bin/lldb ./main --one-line 'b main.rs:2'
(lldb) target create "./main"
Current executable set to '/home/asm/hacking/llvm/rust/main' (x86_64).
(lldb) b main.rs:2
Breakpoint 1: where = main`main::main + 4 at main.rs:2:5, address = 0x00000000000076a4
(lldb) r
Process 948449 launched: '/home/asm/hacking/llvm/rust/main' (x86_64)
warning: (x86_64) /lib64/libgcc_s.so.1 No LZMA support found for reading .gnu_debugdata section
Process 948449 stopped
* thread #1, name = 'main', stop reason = breakpoint 1.1
    frame #0: 0x000055555555b6a4 main`main::main at main.rs:2:5
   1    fn main() {
-> 2        println!("Hello world!");
   3    }
(lldb) bt
error: need to add support for DW_TAG_base_type '()' encoded with DW_ATE = 0x7, bit_size = 0
* thread #1, name = 'main', stop reason = breakpoint 1.1
  * frame #0: 0x000055555555b6a4 main`main::main at main.rs:2:5
    frame #1: 0x000055555555b78b main`<fn() as core::ops::function::FnOnce<()>>::call_once((null)=(main`main::main at main.rs:1), (null)=<unavailable>) at function.rs:227:5
    frame #2: 0x000055555555b66e main`std::sys_common::backtrace::__rust_begin_short_backtrace::<fn(), ()>(f=(main`main::main at main.rs:1)) at backtrace.rs:125:18
    frame #3: 0x000055555555b851 main`std::rt::lang_start::<()>::{closure#0} at rt.rs:49:18
    frame #4: 0x000055555556c9f9 main`std::rt::lang_start_internal::hc51399759a90501a [inlined] core::ops::function::impls::_$LT$impl$u20$core..ops..function..FnOnce$LT$A$GT$$u20$for$u20$$RF$F$GT$::call_once::h04259e4a34d07c2f at function.rs:259:13
    frame #5: 0x000055555556c9f2 main`std::rt::lang_start_internal::hc51399759a90501a [inlined] std::panicking::try::do_call::hb8da45704d5cfbbf at panicking.rs:401:40
    frame #6: 0x000055555556c9f2 main`std::rt::lang_start_internal::hc51399759a90501a [inlined] std::panicking::try::h4beadc19a78fec52 at panicking.rs:365:19
    frame #7: 0x000055555556c9f2 main`std::rt::lang_start_internal::hc51399759a90501a [inlined] std::panic::catch_unwind::hc58016cd36ba81a4 at panic.rs:433:14
    frame #8: 0x000055555556c9f2 main`std::rt::lang_start_internal::hc51399759a90501a at rt.rs:34:21
    frame #9: 0x000055555555b830 main`std::rt::lang_start::<()>(main=(main`main::main at main.rs:1), argc=1, argv=0x00007fffffffcb18) at rt.rs:48:5
    frame #10: 0x000055555555b6fc main`main + 28
    frame #11: 0x00007ffff73f2493 libc.so.6`__libc_start_main + 243
    frame #12: 0x000055555555b59e main`_start + 46
(lldb)
```

[1]: https://github.com/rust-lang/rust/issues/60705

Reviewed By: clayborg, teemperor

Differential Revision: https://reviews.llvm.org/D104054
2021-06-21 18:20:15 +02:00
..
ArmUnwindInfo.cpp [lldb] NFC: Fix trivial typo in comments, documents, and messages 2020-04-07 01:06:16 +09:00
Block.cpp [lldb][NFC] Fix all formatting errors in .cpp file headers 2020-01-24 08:52:55 +01:00
CMakeLists.txt [lldb] Move and clean-up the Declaration class (NFC) 2021-05-04 16:34:44 +00:00
CompactUnwindInfo.cpp [lldb][NFC] Fix all formatting errors in .cpp file headers 2020-01-24 08:52:55 +01:00
CompileUnit.cpp [lldb] Refactor argument group by SourceLocationSpec (NFCI) 2021-05-04 23:04:31 +00:00
CompilerDecl.cpp [lldb][NFC] Fix all formatting errors in .cpp file headers 2020-01-24 08:52:55 +01:00
CompilerDeclContext.cpp [lldb][NFC] Fix all formatting errors in .cpp file headers 2020-01-24 08:52:55 +01:00
CompilerType.cpp [lldb][NFC] Give CompilerType's IsArrayType/IsVectorType/IsBlockPointerType out-parameters default values 2021-02-23 11:15:31 +01:00
DWARFCallFrameInfo.cpp [lldb] Abstract scoped timer logic behind LLDB_SCOPED_TIMER (NFC) 2020-12-22 09:10:27 -08:00
DebugMacros.cpp [lldb][NFC] Fix all formatting errors in .cpp file headers 2020-01-24 08:52:55 +01:00
DeclVendor.cpp [lldb][NFC] Fix all formatting errors in .cpp file headers 2020-01-24 08:52:55 +01:00
FuncUnwinders.cpp [lldb][NFC] Add 'override' where missing in source/ and tools/ 2020-07-15 11:34:47 -07:00
Function.cpp Target::ReadMemory read from read-only binary file Section, not memory 2021-04-16 16:13:07 -07:00
LineEntry.cpp [lldb] Use C++11 default member initializers 2021-06-09 09:43:13 -07:00
LineTable.cpp [lldb/Symbol] Fix column breakpoint `move_to_nearest_code` match 2021-05-05 05:07:50 +00:00
LocateSymbolFile.cpp [lldb] Abstract scoped timer logic behind LLDB_SCOPED_TIMER (NFC) 2020-12-22 09:10:27 -08:00
LocateSymbolFileMacOSX.cpp Ignore DBGArchitecture from dsymForUUID's plist 2020-12-09 14:19:55 -08:00
ObjectFile.cpp Improve performance when parsing symbol tables in mach-o files. 2021-06-02 10:31:37 -07:00
PostfixExpression.cpp [lldb][NFC] Fix all formatting errors in .cpp file headers 2020-01-24 08:52:55 +01:00
Symbol.cpp [lldb] Use C++11 default member initializers 2021-06-09 09:43:13 -07:00
SymbolContext.cpp [lldb] Use C++11 default member initializers 2021-06-09 09:43:13 -07:00
SymbolFile.cpp [lldb] Refactor argument group by SourceLocationSpec (NFCI) 2021-05-04 23:04:31 +00:00
SymbolVendor.cpp [lldb] Delete copy operations on PluginInterface class 2020-10-09 10:37:09 +02:00
Symtab.cpp [lldb] Enable Rust v0 symbol demangling 2021-06-21 18:20:15 +02:00
Type.cpp [lldb] Use C++11 default member initializers 2021-06-09 09:43:13 -07:00
TypeList.cpp Make llvm::StringRef to std::string conversions explicit. 2020-01-28 23:25:25 +01:00
TypeMap.cpp Allow lldb-test to combine -find with -dump-clang-ast 2020-04-17 11:01:20 -07:00
TypeSystem.cpp [lldb] Use C++11 default member initializers 2021-06-09 09:43:13 -07:00
UnwindPlan.cpp [lldb] Use C++11 default member initializers 2021-06-09 09:43:13 -07:00
UnwindTable.cpp [lldb][NFC] Use C++ versions of the deprecated C standard library headers 2021-05-26 12:46:12 +02:00
Variable.cpp Move initialization of Variable::m_loc_is_const_data into constructor (NFC) 2020-10-13 17:01:28 -07:00
VariableList.cpp [lldb][NFC] Fix all formatting errors in .cpp file headers 2020-01-24 08:52:55 +01:00