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
@@ -62,7 +62,7 @@
   size_t MaxRecursionLevel;
   // Current recursion level.
   size_t RecursionLevel;
-
+  size_t BoundLifetimes;
   // Input string that is being demangled with "_R" prefix removed.
   StringView Input;
   // Position in the input string.
@@ -89,6 +89,7 @@
   void demangleGenericArg();
   void demangleType();
   void demangleFnSig();
+  void demangleBinder();
   void demangleConst();
   void demangleConstInt();
   void demangleConstBool();
@@ -122,6 +123,7 @@
   }
 
   void printBasicType(BasicType);
+  void printLifetime(uint64_t Index);
 
   char look() const {
     if (Error || Position >= Input.size())
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
@@ -103,6 +103,7 @@
   Error = false;
   Print = true;
   RecursionLevel = 0;
+  BoundLifetimes = 0;
 
   if (!Mangled.consumeFront("_R")) {
     Error = true;
@@ -242,11 +243,12 @@
 //               | "K" <const>
 // <lifetime> = "L" <base-62-number>
 void Demangler::demangleGenericArg() {
-  if (consumeIf('K'))
+  if (consumeIf('L'))
+    printLifetime(parseBase62Number());
+  else if (consumeIf('K'))
     demangleConst();
   else
     demangleType();
-  // FIXME demangle lifetimes.
 }
 
 // <basic-type> = "a"      // i8
@@ -455,13 +457,24 @@
     break;
   }
   case 'R':
-    print("&");
-    // FIXME demangle [<lifetime>].
+    print('&');
+    if (consumeIf('L')) {
+      if (auto Lifetime = parseBase62Number()) {
+        printLifetime(Lifetime);
+        print(' ');
+      }
+    }
     demangleType();
     break;
   case 'Q':
-    print("&mut ");
-    // FIXME demangle [<lifetime>].
+    print('&');
+    if (consumeIf('L')) {
+      if (auto Lifetime = parseBase62Number()) {
+        printLifetime(Lifetime);
+        print(' ');
+      }
+    }
+    print("mut ");
     demangleType();
     break;
   case 'P':
@@ -486,7 +499,8 @@
 // <abi> = "C"
 //       | <undisambiguated-identifier>
 void Demangler::demangleFnSig() {
-  // FIXME demangle binder.
+  SwapAndRestore<size_t> SaveBoundLifetimes(BoundLifetimes, BoundLifetimes);
+  demangleBinder();
 
   if (consumeIf('U'))
     print("unsafe ");
@@ -523,6 +537,32 @@
   }
 }
 
+// Demangles optional binder and updates the number of bound lifetimes.
+//
+// <binder> = ["G" <base-62-number>]
+void Demangler::demangleBinder() {
+  uint64_t Binder = parseOptionalBase62Number('G');
+  if (Error || Binder == 0)
+    return;
+
+  // Use the input size as a weak upper bound on the total number of bound
+  // lifetimes. Inputs exceeding the bound are invalid, but could generate
+  // excessive amounts of output.
+  if (Binder >= Input.size() - BoundLifetimes) {
+    Error = true;
+    return;
+  }
+
+  print("for<");
+  for (size_t I = 0; I != Binder; ++I) {
+    BoundLifetimes += 1;
+    if (I > 0)
+      print(", ");
+    printLifetime(1);
+  }
+  print("> ");
+}
+
 // <const> = <basic-type> <const-data>
 //         | "p"                          // placeholder
 //         | <backref>
@@ -788,3 +828,28 @@
   HexDigits = Input.substr(Start, End - Start);
   return Value;
 }
+
+// Prints a lifetime. An index 0 always represents an erased lifetime. Indices
+// starting from 1, are De Bruijn indices, referring to higher-ranked lifetimes
+// bound by one of the enclosing binders.
+void Demangler::printLifetime(uint64_t Index) {
+  if (Index == 0) {
+    print("'_");
+    return;
+  }
+
+  if (Index - 1 >= BoundLifetimes) {
+    Error = true;
+    return;
+  }
+
+  uint64_t Depth = BoundLifetimes - Index;
+  print('\'');
+  if (Depth < 26) {
+    char C = 'a' + Depth;
+    print(C);
+  } else {
+    print('z');
+    printDecimalNumber(Depth - 26 + 1);
+  }
+}
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
@@ -70,6 +70,16 @@
 CHECK: generic_const::<_>
        _RIC13generic_constKpE
 
+; Generic lifetime arguments
+
+CHECK: generic_lifetime::<'_>
+       _RIC16generic_lifetimeL_E
+
+; Invalid lifetime index.
+
+CHECK: _RIC16generic_lifetimeL0_E
+       _RIC16generic_lifetimeL0_E
+
 ; Basic types
 
 CHECK: basic::<i8>
@@ -178,9 +188,15 @@
 CHECK: types::<&_>
        _RIC5typesRpE
 
+CHECK: types::<&_>
+       _RIC5typesRL_pE
+
 CHECK: types::<&mut _>
        _RIC5typesQpE
 
+CHECK: types::<&mut _>
+       _RIC5typesQL_pE
+
 CHECK: types::<*const _>
        _RIC5typesPpE
 
@@ -216,6 +232,25 @@
 CHECK: function::<unsafe extern "C-cmse-nonsecure-call" fn()>
        _RIC8functionFUK21C_cmse_nonsecure_callEuE
 
+; Binders
+
+CHECK: binders::<for<'a> fn(&'a _)>
+       _RIC7bindersFG_RL0_pEuE
+
+CHECK: binders::<for<'a, 'b> fn(&'a _, &'b _)>
+       _RIC7bindersFG0_RL1_pRL0_pEuE
+
+CHECK: binders::<for<'a, 'b> fn() -> for<'c, 'd> fn(&'a _, &'d _)>
+       _RIC7bindersFG0_EFG0_RL3_pRL0_pEuE
+
+CHECK: binders::<for<'a, 'b, 'c, 'd, 'e, 'f, 'g, 'h, 'i, 'j, 'k, 'l, 'm, 'n, 'o, 'p, 'q, 'r, 's, 't, 'u, 'v, 'w, 'x, 'y, 'z, 'z1, 'z2, 'z3, 'z4> fn(&'a &'b &'c &'d &'e &'f &'g &'h &'i &'j &'k &'l &'m &'n &'o &'p &'q &'r &'s &'t &'u &'v &'w &'x &'y &'z &'z1 &'z2 &'z3 &'z4 ())>
+       _RIC7bindersFGs_RLt_RLs_RLr_RLq_RLp_RLo_RLn_RLm_RLl_RLk_RLj_RLi_RLh_RLg_RLf_RLe_RLd_RLc_RLb_RLa_RL9_RL8_RL7_RL6_RL5_RL4_RL3_RL2_RL1_RL0_uEuE
+
+; Invalid binder. Too many bound lifetimes.
+
+CHECK: _RIC7bindersFGFF_EuE
+       _RIC7bindersFGFF_EuE
+
 ; Integer constants. Test value demangling.
 
 CHECK: integer::<0>