[llvm] 44d63c5 - [Demangle][Rust] Parse type backreferences

[Tomasz Miąsko via llvm-commits]

Author: Tomasz Miąsko
Date: 2021-06-08T10:01:49+02:00
New Revision: 44d63c57c129f6c784460070c30cb736dbbdb927

URL: https://github.com/llvm/llvm-project/commit/44d63c57c129f6c784460070c30cb736dbbdb927
DIFF: https://github.com/llvm/llvm-project/commit/44d63c57c129f6c784460070c30cb736dbbdb927.diff

LOG: [Demangle][Rust] Parse type backreferences

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D103847

Added: 
    

Modified: 
    llvm/lib/Demangle/RustDemangle.cpp
    llvm/test/Demangle/rust.test

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Demangle/RustDemangle.cpp b/llvm/lib/Demangle/RustDemangle.cpp
index 3ce73f5d935f..4a8f35b8df7a 100644
--- a/llvm/lib/Demangle/RustDemangle.cpp
+++ b/llvm/lib/Demangle/RustDemangle.cpp
@@ -438,8 +438,13 @@ void Demangler::printBasicType(BasicType Type) {
 //          | "D" <dyn-bounds> <lifetime> // dyn Trait<Assoc = X> + Send + 'a
 //          | <backref>                   // backref
 void Demangler::demangleType() {
-  size_t Start = Position;
+  if (Error || RecursionLevel >= MaxRecursionLevel) {
+    Error = true;
+    return;
+  }
+  SwapAndRestore<size_t> SaveRecursionLevel(RecursionLevel, RecursionLevel + 1);
 
+  size_t Start = Position;
   char C = consume();
   BasicType Type;
   if (parseBasicType(C, Type))
@@ -506,6 +511,9 @@ void Demangler::demangleType() {
       Error = true;
     }
     break;
+  case 'B':
+    demangleBackref([&] { demangleType(); });
+    break;
   default:
     Position = Start;
     demanglePath(rust_demangle::InType::Yes);

diff  --git a/llvm/test/Demangle/rust.test b/llvm/test/Demangle/rust.test
index 64255336857c..1c1236d93177 100644
--- a/llvm/test/Demangle/rust.test
+++ b/llvm/test/Demangle/rust.test
@@ -425,6 +425,9 @@ CHECK: _RIC4charKc1234567_E
 CHECK: backref::<backref::ident>
        _RIC7backrefNvB0_5identE
 
+CHECK: backref::<(), ()>
+       _RIC7backrefuB9_E
+
 ; Invalid backreferences
 
 CHECK: _RB_
@@ -436,6 +439,9 @@ CHECK: _RB5_
 CHECK: _RNvB_1a
        _RNvB_1a
 
+CHECK: _RIC7backrefSB9_E
+       _RIC7backrefSB9_E
+
 ; Invalid mangled characters
 
 CHECK: _RNvC2a.1c