Demangle &-qualified function types.

PiperOrigin-RevId: 637972935
Change-Id: Ia684f7761b2a98a0d9d5ae096daba34e9140aa22

2 files changed, 39 insertions, 8 deletions

diff --git a/absl/debugging/internal/demangle.cc b/absl/debugging/internal/demangle.cc
index 38b5458e..91bea72d 100644
--- a/absl/debugging/internal/demangle.cc
+++ b/absl/debugging/internal/demangle.cc
@@ -1386,19 +1386,30 @@ static bool ParseExceptionSpec(State *state) {
   return false;
 }
 
-// <function-type> ::= [exception-spec] F [Y] <bare-function-type> [O] E
+// <function-type> ::=
+//     [exception-spec] F [Y] <bare-function-type> [<ref-qualifier>] E
+//
+// <ref-qualifier> ::= R | O
 static bool ParseFunctionType(State *state) {
   ComplexityGuard guard(state);
   if (guard.IsTooComplex()) return false;
   ParseState copy = state->parse_state;
-  if (Optional(ParseExceptionSpec(state)) && ParseOneCharToken(state, 'F') &&
-      Optional(ParseOneCharToken(state, 'Y')) && ParseBareFunctionType(state) &&
-      Optional(ParseOneCharToken(state, 'O')) &&
-      ParseOneCharToken(state, 'E')) {
-    return true;
+  Optional(ParseExceptionSpec(state));
+  if (!ParseOneCharToken(state, 'F')) {
+    state->parse_state = copy;
+    return false;
   }
-  state->parse_state = copy;
-  return false;
+  Optional(ParseOneCharToken(state, 'Y'));
+  if (!ParseBareFunctionType(state)) {
+    state->parse_state = copy;
+    return false;
+  }
+  Optional(ParseCharClass(state, "RO"));
+  if (!ParseOneCharToken(state, 'E')) {
+    state->parse_state = copy;
+    return false;
+  }
+  return true;
 }
 
 // <bare-function-type> ::= <(signature) type>+
diff --git a/absl/debugging/internal/demangle_test.cc b/absl/debugging/internal/demangle_test.cc
index 2cfd1f95..0195e5a7 100644
--- a/absl/debugging/internal/demangle_test.cc
+++ b/absl/debugging/internal/demangle_test.cc
@@ -569,6 +569,26 @@ TEST(Demangle, DirectListInitialization) {
   EXPECT_STREQ("j<>()", tmp);
 }
 
+TEST(Demangle, ReferenceQualifiedFunctionTypes) {
+  char tmp[80];
+
+  // void f(void (*)() const &, int)
+  EXPECT_TRUE(Demangle("_Z1fPKFvvREi", tmp, sizeof(tmp)));
+  EXPECT_STREQ("f()", tmp);
+
+  // void f(void (*)() &&, int)
+  EXPECT_TRUE(Demangle("_Z1fPFvvOEi", tmp, sizeof(tmp)));
+  EXPECT_STREQ("f()", tmp);
+
+  // void f(void (*)(int&) &, int)
+  EXPECT_TRUE(Demangle("_Z1fPFvRiREi", tmp, sizeof(tmp)));
+  EXPECT_STREQ("f()", tmp);
+
+  // void f(void (*)(S&&) &&, int)
+  EXPECT_TRUE(Demangle("_Z1fPFvO1SOEi", tmp, sizeof(tmp)));
+  EXPECT_STREQ("f()", tmp);
+}
+
 // Test one Rust symbol to exercise Demangle's delegation path.  Rust demangling
 // itself is more thoroughly tested in demangle_rust_test.cc.
 TEST(Demangle, DelegatesToDemangleRustSymbolEncoding) {