Bug 445235 - Java/Ada/D demangling is probably broken
Summary: Java/Ada/D demangling is probably broken
Status: REPORTED
Alias: None
Product: valgrind
Classification: Developer tools
Component: general (show other bugs)
Version: unspecified
Platform: Other Linux
: NOR normal (vote)
Target Milestone: ---
Assignee: Julian Seward
URL:
Keywords:
Depends on: 445184
Blocks:
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Reported: 2021-11-09 22:52 UTC by Nick Nethercote
Modified: 2021-11-12 08:49 UTC (History)
4 users (show)

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Description Nick Nethercote 2021-11-09 22:52:43 UTC
+++ This bug was initially created as a clone of Bug #445184 +++

Valgrind has code to demangle symbols for: C++, Rust, Java, Ada, and D. But the Java/Ada/D demangling is probably broken because the code is unreachable.

`VG_(demangle)` has an initial test that requires that the first two chars be "_Z" or "_R", which excludes a bunch of cases. Also, the code in `ML_(cplus_demangle)` that calls the demanglers for Java/Ada/D is a bit different to that for C++ and Rust (in the way the `*_DEMANGLING` constants are used), which may also be a problem.

From a quick look at the code, I think the following is true.
- C++ symbols usually start with "_Z", but "_GLOBAL_" is also possible, which won't work.
- Rust symbols start with "_Z" or "_R".
- Java symbols are a subset of C++ symbols, so should be ok, modulo possible "_GLOBAL_" cases, and possible AUTO_DEMANGLING problems.
- D symbols start with "_D", and so will be broken.
- Ada symbols can start with "_ada_", or with a lower-case letter, and so will be broken.