[Demangle][Rust] Parse dyn-trait-assoc-binding

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D103364

1 files changed, 26 insertions, 6 deletions

diff --git a/llvm/lib/Demangle/RustDemangle.cpp b/llvm/lib/Demangle/RustDemangle.cpp
index cbb52fa..9513a00 100644
--- a/llvm/lib/Demangle/RustDemangle.cpp
+++ b/llvm/lib/Demangle/RustDemangle.cpp
@@ -121,7 +121,10 @@ bool Demangler::demangle(StringView Mangled) {
   return !Error;
 }
 
-// Demangles a path. InType indicates whether a path is inside a type.
+// Demangles a path. InType indicates whether a path is inside a type. When
+// LeaveOpen is true, a closing `>` after generic arguments is omitted from the
+// output. Return value indicates whether generics arguments have been left
+// open.
 //
 // <path> = "C" <identifier>               // crate root
 //        | "M" <impl-path> <type>         // <T> (inherent impl)
@@ -135,10 +138,10 @@ bool Demangler::demangle(StringView Mangled) {
 //      | "S"      // shim
 //      | <A-Z>    // other special namespaces
 //      | <a-z>    // internal namespaces
-void Demangler::demanglePath(InType InType) {
+bool Demangler::demanglePath(InType InType, LeaveOpen LeaveOpen) {
   if (Error || RecursionLevel >= MaxRecursionLevel) {
     Error = true;
-    return;
+    return false;
   }
   SwapAndRestore<size_t> SaveRecursionLevel(RecursionLevel, RecursionLevel + 1);
 
@@ -220,7 +223,10 @@ void Demangler::demanglePath(InType InType) {
         print(", ");
       demangleGenericArg();
     }
-    print(">");
+    if (LeaveOpen == rust_demangle::LeaveOpen::Yes)
+      return true;
+    else
+      print(">");
     break;
   }
   default:
@@ -228,6 +234,8 @@ void Demangler::demanglePath(InType InType) {
     Error = true;
     break;
   }
+
+  return false;
 }
 
 // <impl-path> = [<disambiguator>] <path>
@@ -555,8 +563,20 @@ void Demangler::demangleDynBounds() {
 // <dyn-trait> = <path> {<dyn-trait-assoc-binding>}
 // <dyn-trait-assoc-binding> = "p" <undisambiguated-identifier> <type>
 void Demangler::demangleDynTrait() {
-  demanglePath(InType::Yes);
-  // FIXME demangle {<dyn-trait-assoc-binding>}
+  bool IsOpen = demanglePath(InType::Yes, LeaveOpen::Yes);
+  while (!Error && consumeIf('p')) {
+    if (!IsOpen) {
+      IsOpen = true;
+      print('<');
+    } else {
+      print(", ");
+    }
+    print(parseIdentifier().Name);
+    print(" = ");
+    demangleType();
+  }
+  if (IsOpen)
+    print(">");
 }
 
 // Demangles optional binder and updates the number of bound lifetimes.