[Demangle][Rust] Parse instantiating crate

[tmiasko]

Summary

Depends on D103459

[dblaikie]

Looks good, thanks!

llvm/lib/Demangle/RustDemangle.cpp

bool Demangler::demangle(StringView Mangled) {
   if (!Mangled.consumeFront("_R")) {
     Error = true;
     return false;
   }
   Input = Mangled;
 
   demanglePath(rust_demangle::InType::No);
 
-  // FIXME parse optional <instantiating-crate>.
+  if (Position != Input.size()) {
+    SwapAndRestore<bool> SavePrint(Print, false);
+    demanglePath(InType::No);
+  }
 
   if (Position != Input.size())
     Error = true;
 
   return !Error;
 }
 
 // Demangles a path. InType indicates whether a path is inside a type. When

llvm/test/Demangle/rust.test

 RUN: llvm-cxxfilt -n  < %s | FileCheck --match-full-lines %s
 
 CHECK: a::main
        _RNvC1a4main
 
 CHECK: hello::rust
        _RNvCshGpAVYOtgW1_5hello4rust
 
 CHECK: a::b::c
        _RNvNvC1a1b1c
 
+; Instantiating crate
+
+CHECK: crate
+       _RC5crateC3foo
+
 ; Closure namespace
 
 CHECK: crate::{closure#0}
        _RNCC5crate0
 
 CHECK: crate::{closure#1}
        _RNCC5crates_0