GNU demangler doesn't demangle anything on MacOS M1

[alexdevsec]

When I use the Ghidra demangler tool from the GUI, it doesn't demangle any symbol names. I tracked it down to the GNU demangler doing nothing. This might be because I'm on macOS Monterey 12.6 on an M1.

For instance, when I run:

$ cd ghidra_10.1.5_PUBLIC/GPL/DemanglerGnu/os/mac_x86_64/ $ ./demangler_gnu_v2_33_1 __ZTISt12length_error __ZTISt12length_error

... it doesn't do any conversion, it just repeats the input because it couldn't demangle.

I get the same thing with v2_24.

Here's the same result using c++filt which comes with Xcode command line tools:

$ /usr/bin/c++filt __ZTISt12length_error typeinfo for std::length_error

This information appears correct.

A workaround might be to point the Ghidra demangler tool to use c++filt, but I don't know how to do that.

Ghidra version: 10.1.5 OS: MacOS Monterey 12.6 on an M1

[dragonmacher]

The issue with this example for the demangler we ship is that there are two leading underscores. I tried this on Linux and it does not work using demangler_gnu_v2_33_1 or using c++filt. Both tools worked as expected when I removed one of the leading underscores.

Ghidra has code to check for __Z and remove one of the underscores. I added the above mangled text as a label to Ghidra. Then, with my cursor on that label, I ran the Ghidra script DemangleSymbolScript.java. This demangled the symbol as expected. Running the Demangler Gnu analyzer also found and demangled the symbol.

[ryanmkurtz]

Note that we have things setup on an M1 such that it will use the x86_64 native executable with Rosetta 2 if an aarch64 version is not available, which is the case with the GNU demangler.

[lnchan]

I would like to add that this also applies to the decompiler binaries (and all other native binaries packaged within Ghidra releases), as none of them are built for aarch64-apple-darwin. Ghidra seems to default to x86_64-apple-darwin at runtime, regardless of the currently running architecture.

[ryanmkurtz]

We do not ship aarch64 binaries with our releases. However, we provide the ability to build them yourself for your native platform. Just run support/buildNatives.