diff --git a/llvm/include/llvm/Demangle/RustDemangle.h b/llvm/include/llvm/Demangle/RustDemangle.h
--- a/llvm/include/llvm/Demangle/RustDemangle.h
+++ b/llvm/include/llvm/Demangle/RustDemangle.h
@@ -84,7 +84,7 @@
   bool demangle(StringView MangledName);
 
 private:
-  void demanglePath(InType InType);
+  bool demanglePath(InType InType, bool LeaveOpen = false);
   void demangleImplPath(InType InType);
   void demangleGenericArg();
   void demangleType();
diff --git a/llvm/lib/Demangle/RustDemangle.cpp b/llvm/lib/Demangle/RustDemangle.cpp
--- a/llvm/lib/Demangle/RustDemangle.cpp
+++ b/llvm/lib/Demangle/RustDemangle.cpp
@@ -121,7 +121,10 @@
   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)
@@ -135,12 +138,13 @@
 //      | "S"      // shim
 //      | <A-Z>    // other special namespaces
 //      | <a-z>    // internal namespaces
-void Demangler::demanglePath(InType InType) {
+bool Demangler::demanglePath(InType InType, bool LeaveOpen) {
   if (Error || RecursionLevel >= MaxRecursionLevel) {
     Error = true;
-    return;
+    return false;
   }
   SwapAndRestore<size_t> SaveRecursionLevel(RecursionLevel, RecursionLevel + 1);
+  bool IsOpen = false;
 
   switch (consume()) {
   case 'C': {
@@ -220,7 +224,10 @@
         print(", ");
       demangleGenericArg();
     }
-    print(">");
+    if (LeaveOpen)
+      IsOpen = true;
+    else
+      print(">");
     break;
   }
   default:
@@ -228,6 +235,8 @@
     Error = true;
     break;
   }
+
+  return IsOpen;
 }
 
 // <impl-path> = [<disambiguator>] <path>
@@ -555,8 +564,20 @@
 // <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, true /* LeaveOpen */);
+  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.
diff --git a/llvm/test/Demangle/rust.test b/llvm/test/Demangle/rust.test
--- a/llvm/test/Demangle/rust.test
+++ b/llvm/test/Demangle/rust.test
@@ -252,6 +252,15 @@
 CHECK: trait::<dyn for<'a> Display>
        _RIC5traitDG_C7DisplayEL_E
 
+CHECK: trait::<dyn IntoIterator<_, Item = _>>
+       _RIC5traitDIC12IntoIteratorpEp4ItempEL_E
+
+CHECK: trait::<dyn IntoIterator<Item = _>>
+       _RIC5traitDC12IntoIteratorp4ItempEL_E
+
+CHECK: trait::<dyn IntoIterator<Item = _, IntoIter = _>>
+       _RIC5traitDC12IntoIteratorp4Itempp8IntoIterpEL_E
+
 ; Invalid trait object, missing lifetime.
 
 CHECK: _RIC5traitDEE