Demangle elaborated type names, (Ts | Tu | Te) <name>.

PiperOrigin-RevId: 640972027
Change-Id: I810aaa10e7761686d03854abab3198be8b2868cf

absl/debugging/internal/demangle.cc

@@ -1544,10 +1544,23 @@ static bool ParseOverloadAttribute(State *state) {
 }
 }
 
 
 // <class-enum-type> ::= <name>
 // <class-enum-type> ::= <name>
+//                   ::= Ts <name>  # struct Name or class Name
+//                   ::= Tu <name>  # union Name
+//                   ::= Te <name>  # enum Name
+//
+// See http://shortn/_W3YrltiEd0.
 static bool ParseClassEnumType(State *state) {
 static bool ParseClassEnumType(State *state) {
   ComplexityGuard guard(state);
   ComplexityGuard guard(state);
   if (guard.IsTooComplex()) return false;
   if (guard.IsTooComplex()) return false;
-  return ParseName(state);
+  ParseState copy = state->parse_state;
+  if (Optional(ParseTwoCharToken(state, "Ts") ||
+               ParseTwoCharToken(state, "Tu") ||
+               ParseTwoCharToken(state, "Te")) &&
+      ParseName(state)) {
+    return true;
+  }
+  state->parse_state = copy;
+  return false;
 }
 }
 
 
 // <array-type> ::= A <(positive dimension) number> _ <(element) type>
 // <array-type> ::= A <(positive dimension) number> _ <(element) type>

absl/debugging/internal/demangle_test.cc

@@ -739,6 +739,30 @@ TEST(Demangle, TypeNestedUnderDecltype) {
   EXPECT_STREQ("f<>()", tmp);
   EXPECT_STREQ("f<>()", tmp);
 }
 }
 
 
+TEST(Demangle, ElaboratedTypes) {
+  char tmp[80];
+
+  // Source:
+  //
+  // template <class T> struct S { class C {}; };
+  // template <class T> void f(class S<T>::C) {}
+  // template void f<int>(class S<int>::C);
+  //
+  // LLVM demangling:
+  //
+  // void f<int>(struct S<int>::C)
+  EXPECT_TRUE(Demangle("_Z1fIiEvTsN1SIT_E1CE", tmp, sizeof(tmp)));
+  EXPECT_STREQ("f<>()", tmp);
+
+  // The like for unions.
+  EXPECT_TRUE(Demangle("_Z1fIiEvTuN1SIT_E1CE", tmp, sizeof(tmp)));
+  EXPECT_STREQ("f<>()", tmp);
+
+  // The like for enums.
+  EXPECT_TRUE(Demangle("_Z1fIiEvTeN1SIT_E1CE", tmp, sizeof(tmp)));
+  EXPECT_STREQ("f<>()", tmp);
+}
+
 // Test subobject-address template parameters.
 // Test subobject-address template parameters.
 TEST(Demangle, SubobjectAddresses) {
 TEST(Demangle, SubobjectAddresses) {
   char tmp[80];
   char tmp[80];