NFC: Make the copies of the demangler byte-for-byte identical
With this patch, the copies of the files ItaniumDemangle.h,
StringView.h, and Utility.h are kept byte-for-byte in sync between
libcxxabi and llvm. All differences (namespaces, fallthrough, and
unreachable macros) are defined in each copies' DemanglerConfig.h.
This patch also adds a script to copy changes from libcxxabi
(cp-to-llvm.sh), and a README.txt explaining the situation.
Differential revision: https://reviews.llvm.org/D53538
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351474 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/Demangle/Compiler.h b/include/llvm/Demangle/Compiler.h
deleted file mode 100644
index 248d6e3..0000000
--- a/include/llvm/Demangle/Compiler.h
+++ /dev/null
@@ -1,93 +0,0 @@
-//===--- Compiler.h ---------------------------------------------*- C++ -*-===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//
-// This file contains a variety of feature test macros copied from
-// include/llvm/Support/Compiler.h so that LLVMDemangle does not need to take
-// a dependency on LLVMSupport.
-//===----------------------------------------------------------------------===//
-
-#ifndef LLVM_DEMANGLE_COMPILER_H
-#define LLVM_DEMANGLE_COMPILER_H
-
-#ifdef _MSC_VER
-// snprintf is implemented in VS 2015
-#if _MSC_VER < 1900
-#define snprintf _snprintf_s
-#endif
-#endif
-
-#ifndef __has_feature
-#define __has_feature(x) 0
-#endif
-
-#ifndef __has_cpp_attribute
-#define __has_cpp_attribute(x) 0
-#endif
-
-#ifndef __has_attribute
-#define __has_attribute(x) 0
-#endif
-
-#ifndef __has_builtin
-#define __has_builtin(x) 0
-#endif
-
-#ifndef LLVM_GNUC_PREREQ
-#if defined(__GNUC__) && defined(__GNUC_MINOR__) && defined(__GNUC_PATCHLEVEL__)
-#define LLVM_GNUC_PREREQ(maj, min, patch) \
- ((__GNUC__ << 20) + (__GNUC_MINOR__ << 10) + __GNUC_PATCHLEVEL__ >= \
- ((maj) << 20) + ((min) << 10) + (patch))
-#elif defined(__GNUC__) && defined(__GNUC_MINOR__)
-#define LLVM_GNUC_PREREQ(maj, min, patch) \
- ((__GNUC__ << 20) + (__GNUC_MINOR__ << 10) >= ((maj) << 20) + ((min) << 10))
-#else
-#define LLVM_GNUC_PREREQ(maj, min, patch) 0
-#endif
-#endif
-
-#if __has_attribute(used) || LLVM_GNUC_PREREQ(3, 1, 0)
-#define LLVM_ATTRIBUTE_USED __attribute__((__used__))
-#else
-#define LLVM_ATTRIBUTE_USED
-#endif
-
-#if __has_builtin(__builtin_unreachable) || LLVM_GNUC_PREREQ(4, 5, 0)
-#define LLVM_BUILTIN_UNREACHABLE __builtin_unreachable()
-#elif defined(_MSC_VER)
-#define LLVM_BUILTIN_UNREACHABLE __assume(false)
-#endif
-
-#if __has_attribute(noinline) || LLVM_GNUC_PREREQ(3, 4, 0)
-#define LLVM_ATTRIBUTE_NOINLINE __attribute__((noinline))
-#elif defined(_MSC_VER)
-#define LLVM_ATTRIBUTE_NOINLINE __declspec(noinline)
-#else
-#define LLVM_ATTRIBUTE_NOINLINE
-#endif
-
-#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
-#define LLVM_DUMP_METHOD LLVM_ATTRIBUTE_NOINLINE LLVM_ATTRIBUTE_USED
-#else
-#define LLVM_DUMP_METHOD LLVM_ATTRIBUTE_NOINLINE
-#endif
-
-#if __cplusplus > 201402L && __has_cpp_attribute(fallthrough)
-#define LLVM_FALLTHROUGH [[fallthrough]]
-#elif __has_cpp_attribute(gnu::fallthrough)
-#define LLVM_FALLTHROUGH [[gnu::fallthrough]]
-#elif !__cplusplus
-// Workaround for llvm.org/PR23435, since clang 3.6 and below emit a spurious
-// error when __has_cpp_attribute is given a scoped attribute in C mode.
-#define LLVM_FALLTHROUGH
-#elif __has_cpp_attribute(clang::fallthrough)
-#define LLVM_FALLTHROUGH [[clang::fallthrough]]
-#else
-#define LLVM_FALLTHROUGH
-#endif
-
-#endif
diff --git a/include/llvm/Demangle/DemangleConfig.h b/include/llvm/Demangle/DemangleConfig.h
new file mode 100644
index 0000000..beaf9a0
--- /dev/null
+++ b/include/llvm/Demangle/DemangleConfig.h
@@ -0,0 +1,98 @@
+//===--- DemangleConfig.h ---------------------------------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains a variety of feature test macros copied from
+// include/llvm/Support/Compiler.h so that LLVMDemangle does not need to take
+// a dependency on LLVMSupport.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_DEMANGLE_COMPILER_H
+#define LLVM_DEMANGLE_COMPILER_H
+
+#ifdef _MSC_VER
+// snprintf is implemented in VS 2015
+#if _MSC_VER < 1900
+#define snprintf _snprintf_s
+#endif
+#endif
+
+#ifndef __has_feature
+#define __has_feature(x) 0
+#endif
+
+#ifndef __has_cpp_attribute
+#define __has_cpp_attribute(x) 0
+#endif
+
+#ifndef __has_attribute
+#define __has_attribute(x) 0
+#endif
+
+#ifndef __has_builtin
+#define __has_builtin(x) 0
+#endif
+
+#ifndef DEMANGLE_GNUC_PREREQ
+#if defined(__GNUC__) && defined(__GNUC_MINOR__) && defined(__GNUC_PATCHLEVEL__)
+#define DEMANGLE_GNUC_PREREQ(maj, min, patch) \
+ ((__GNUC__ << 20) + (__GNUC_MINOR__ << 10) + __GNUC_PATCHLEVEL__ >= \
+ ((maj) << 20) + ((min) << 10) + (patch))
+#elif defined(__GNUC__) && defined(__GNUC_MINOR__)
+#define DEMANGLE_GNUC_PREREQ(maj, min, patch) \
+ ((__GNUC__ << 20) + (__GNUC_MINOR__ << 10) >= ((maj) << 20) + ((min) << 10))
+#else
+#define DEMANGLE_GNUC_PREREQ(maj, min, patch) 0
+#endif
+#endif
+
+#if __has_attribute(used) || DEMANGLE_GNUC_PREREQ(3, 1, 0)
+#define DEMANGLE_ATTRIBUTE_USED __attribute__((__used__))
+#else
+#define DEMANGLE_ATTRIBUTE_USED
+#endif
+
+#if __has_builtin(__builtin_unreachable) || DEMANGLE_GNUC_PREREQ(4, 5, 0)
+#define DEMANGLE_UNREACHABLE __builtin_unreachable()
+#elif defined(_MSC_VER)
+#define DEMANGLE_BUILTIN_UNREACHABLE __assume(false)
+#endif
+
+#if __has_attribute(noinline) || DEMANGLE_GNUC_PREREQ(3, 4, 0)
+#define DEMANGLE_ATTRIBUTE_NOINLINE __attribute__((noinline))
+#elif defined(_MSC_VER)
+#define DEMANGLE_ATTRIBUTE_NOINLINE __declspec(noinline)
+#else
+#define DEMANGLE_ATTRIBUTE_NOINLINE
+#endif
+
+#if !defined(NDEBUG)
+#define DEMANGLE_DUMP_METHOD DEMANGLE_ATTRIBUTE_NOINLINE DEMANGLE_ATTRIBUTE_USED
+#else
+#define DEMANGLE_DUMP_METHOD DEMANGLE_ATTRIBUTE_NOINLINE
+#endif
+
+#if __cplusplus > 201402L && __has_cpp_attribute(fallthrough)
+#define DEMANGLE_FALLTHROUGH [[fallthrough]]
+#elif __has_cpp_attribute(gnu::fallthrough)
+#define DEMANGLE_FALLTHROUGH [[gnu::fallthrough]]
+#elif !__cplusplus
+// Workaround for llvm.org/PR23435, since clang 3.6 and below emit a spurious
+// error when __has_cpp_attribute is given a scoped attribute in C mode.
+#define DEMANGLE_FALLTHROUGH
+#elif __has_cpp_attribute(clang::fallthrough)
+#define DEMANGLE_FALLTHROUGH [[clang::fallthrough]]
+#else
+#define DEMANGLE_FALLTHROUGH
+#endif
+
+#define DEMANGLE_NAMESPACE_BEGIN namespace llvm { namespace itanium_demangle {
+#define DEMANGLE_NAMESPACE_END } }
+
+#endif
diff --git a/include/llvm/Demangle/ItaniumDemangle.h b/include/llvm/Demangle/ItaniumDemangle.h
index 0b9187f..53107c9 100644
--- a/include/llvm/Demangle/ItaniumDemangle.h
+++ b/include/llvm/Demangle/ItaniumDemangle.h
@@ -6,18 +6,22 @@
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
+//
+// Generic itanium demangler library. This file has two byte-per-byte identical
+// copies in the source tree, one in libcxxabi, and the other in llvm.
+//
+//===----------------------------------------------------------------------===//
-#ifndef LLVM_DEMANGLE_ITANIUMDEMANGLE_H
-#define LLVM_DEMANGLE_ITANIUMDEMANGLE_H
+#ifndef DEMANGLE_ITANIUMDEMANGLE_H
+#define DEMANGLE_ITANIUMDEMANGLE_H
// FIXME: (possibly) incomplete list of features that clang mangles that this
// file does not yet support:
// - C++ modules TS
-#include "llvm/Demangle/Compiler.h"
-#include "llvm/Demangle/StringView.h"
-#include "llvm/Demangle/Utility.h"
-
+#include "DemangleConfig.h"
+#include "StringView.h"
+#include "Utility.h"
#include <cassert>
#include <cctype>
#include <cstdio>
@@ -95,8 +99,8 @@
X(BracedExpr) \
X(BracedRangeExpr)
-namespace llvm {
-namespace itanium_demangle {
+DEMANGLE_NAMESPACE_BEGIN
+
// Base class of all AST nodes. The AST is built by the parser, then is
// traversed by the printLeft/Right functions to produce a demangled string.
class Node {
@@ -194,7 +198,7 @@
virtual ~Node() = default;
#ifndef NDEBUG
- LLVM_DUMP_METHOD void dump() const;
+ DEMANGLE_DUMP_METHOD void dump() const;
#endif
};
@@ -1278,7 +1282,7 @@
case SpecialSubKind::iostream:
return StringView("basic_iostream");
}
- LLVM_BUILTIN_UNREACHABLE;
+ DEMANGLE_UNREACHABLE;
}
void printLeft(OutputStream &S) const override {
@@ -1330,7 +1334,7 @@
case SpecialSubKind::iostream:
return StringView("iostream");
}
- LLVM_BUILTIN_UNREACHABLE;
+ DEMANGLE_UNREACHABLE;
}
void printLeft(OutputStream &S) const override {
@@ -3467,7 +3471,7 @@
Result = getDerived().parseFunctionType();
break;
}
- LLVM_FALLTHROUGH;
+ DEMANGLE_FALLTHROUGH;
}
case 'U': {
Result = getDerived().parseQualifiedType();
@@ -3754,7 +3758,7 @@
// substitution table.
return Sub;
}
- LLVM_FALLTHROUGH;
+ DEMANGLE_FALLTHROUGH;
}
// ::= <class-enum-type>
default: {
@@ -5178,7 +5182,6 @@
Alloc>::AbstractManglingParser;
};
-} // namespace itanium_demangle
-} // namespace llvm
+DEMANGLE_NAMESPACE_END
-#endif // LLVM_DEMANGLE_ITANIUMDEMANGLE_H
+#endif // DEMANGLE_ITANIUMDEMANGLE_H
diff --git a/include/llvm/Demangle/MicrosoftDemangle.h b/include/llvm/Demangle/MicrosoftDemangle.h
index 97b918f..c0b44cc 100644
--- a/include/llvm/Demangle/MicrosoftDemangle.h
+++ b/include/llvm/Demangle/MicrosoftDemangle.h
@@ -10,7 +10,7 @@
#ifndef LLVM_DEMANGLE_MICROSOFT_DEMANGLE_H
#define LLVM_DEMANGLE_MICROSOFT_DEMANGLE_H
-#include "llvm/Demangle/Compiler.h"
+#include "llvm/Demangle/DemangleConfig.h"
#include "llvm/Demangle/MicrosoftDemangleNodes.h"
#include "llvm/Demangle/StringView.h"
#include "llvm/Demangle/Utility.h"
diff --git a/include/llvm/Demangle/MicrosoftDemangleNodes.h b/include/llvm/Demangle/MicrosoftDemangleNodes.h
index 9e3478e..777d15d 100644
--- a/include/llvm/Demangle/MicrosoftDemangleNodes.h
+++ b/include/llvm/Demangle/MicrosoftDemangleNodes.h
@@ -1,11 +1,31 @@
+//===- MicrosoftDemangleNodes.h ---------------------------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the AST nodes used in the MSVC demangler.
+//
+//===----------------------------------------------------------------------===//
+
#ifndef LLVM_SUPPORT_MICROSOFTDEMANGLENODES_H
#define LLVM_SUPPORT_MICROSOFTDEMANGLENODES_H
-#include "llvm/Demangle/Compiler.h"
+#include "llvm/Demangle/DemangleConfig.h"
#include "llvm/Demangle/StringView.h"
#include <array>
+namespace llvm {
+namespace itanium_demangle {
class OutputStream;
+}
+}
+
+using llvm::itanium_demangle::OutputStream;
+using llvm::itanium_demangle::StringView;
namespace llvm {
namespace ms_demangle {
@@ -602,4 +622,4 @@
} // namespace ms_demangle
} // namespace llvm
-#endif
\ No newline at end of file
+#endif
diff --git a/include/llvm/Demangle/README.txt b/include/llvm/Demangle/README.txt
new file mode 100644
index 0000000..514ff6d
--- /dev/null
+++ b/include/llvm/Demangle/README.txt
@@ -0,0 +1,52 @@
+Itanium Name Demangler Library
+==============================
+
+Introduction
+------------
+
+This directory contains the generic itanium name demangler library. The main
+purpose of the library is to demangle C++ symbols, i.e. convert the string
+"_Z1fv" into "f()". You can also use the CRTP base ManglingParser to perform
+some simple analysis on the mangled name, or (in LLVM) use the opaque
+ItaniumPartialDemangler to query the demangled AST.
+
+Why are there multiple copies of the this library in the source tree?
+---------------------------------------------------------------------
+
+This directory is mirrored between libcxxabi/demangle and
+llvm/include/llvm/Demangle. The simple reason for this is that both projects
+need to demangle symbols, but neither can depend on each other. libcxxabi needs
+the demangler to implement __cxa_demangle, which is part of the itanium ABI
+spec. LLVM needs a copy for a bunch of places, but doesn't want to use the
+system's __cxa_demangle because it a) might not be available (i.e., on Windows),
+and b) probably isn't that up-to-date on the latest language features.
+
+The copy of the demangler in LLVM has some extra stuff that aren't needed in
+libcxxabi (ie, the MSVC demangler, ItaniumPartialDemangler), which depend on the
+shared generic components. Despite these differences, we want to keep the "core"
+generic demangling library identical between both copies to simplify development
+and testing.
+
+If you're working on the generic library, then do the work first in libcxxabi,
+then run the cp-to-llvm.sh script in src/demangle. This script takes as an
+argument the path to llvm, and re-copies the changes you made to libcxxabi over.
+Note that this script just blindly overwrites all changes to the generic library
+in llvm, so be careful.
+
+Because the core demangler needs to work in libcxxabi, everything needs to be
+declared in an anonymous namespace (see DEMANGLE_NAMESPACE_BEGIN), and you can't
+introduce any code that depends on the libcxx dylib.
+
+Hopefully, when LLVM becomes a monorepo, we can de-duplicate this code, and have
+both LLVM and libcxxabi depend on a shared demangler library.
+
+Testing
+-------
+
+The tests are split up between libcxxabi/test/{unit,}test_demangle.cpp, and
+llvm/unittest/Demangle. The llvm directory should only get tests for stuff not
+included in the core library. In the future though, we should probably move all
+the tests to LLVM.
+
+It is also a really good idea to run libFuzzer after non-trivial changes, see
+libcxxabi/fuzz/cxa_demangle_fuzzer.cpp and https://llvm.org/docs/LibFuzzer.html.
diff --git a/include/llvm/Demangle/StringView.h b/include/llvm/Demangle/StringView.h
index a89deda..9af4e06 100644
--- a/include/llvm/Demangle/StringView.h
+++ b/include/llvm/Demangle/StringView.h
@@ -5,18 +5,22 @@
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
+//===----------------------------------------------------------------------===//
//
-// This file contains a limited version of LLVM's StringView class. It is
-// copied here so that LLVMDemangle need not take a dependency on LLVMSupport.
+// FIXME: Use std::string_view instead when we support C++17.
+//
//===----------------------------------------------------------------------===//
-#ifndef LLVM_DEMANGLE_STRINGVIEW_H
-#define LLVM_DEMANGLE_STRINGVIEW_H
+#ifndef DEMANGLE_STRINGVIEW_H
+#define DEMANGLE_STRINGVIEW_H
+#include "DemangleConfig.h"
#include <algorithm>
#include <cassert>
#include <cstring>
+DEMANGLE_NAMESPACE_BEGIN
+
class StringView {
const char *First;
const char *Last;
@@ -43,7 +47,7 @@
if (FindBegin < size()) {
// Just forward to memchr, which is faster than a hand-rolled loop.
if (const void *P = ::memchr(First + FindBegin, C, size() - FindBegin))
- return static_cast<const char *>(P) - First;
+ return size_t(static_cast<const char *>(P) - First);
}
return npos;
}
@@ -118,4 +122,6 @@
std::equal(LHS.begin(), LHS.end(), RHS.begin());
}
+DEMANGLE_NAMESPACE_END
+
#endif
diff --git a/include/llvm/Demangle/Utility.h b/include/llvm/Demangle/Utility.h
index 1d1601c..4d44cd8 100644
--- a/include/llvm/Demangle/Utility.h
+++ b/include/llvm/Demangle/Utility.h
@@ -5,21 +5,24 @@
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
+//===----------------------------------------------------------------------===//
//
-// This file contains several utility classes used by the demangle library.
+// Provide some utility classes for use in the demangler(s).
+//
//===----------------------------------------------------------------------===//
-#ifndef LLVM_DEMANGLE_UTILITY_H
-#define LLVM_DEMANGLE_UTILITY_H
+#ifndef DEMANGLE_UTILITY_H
+#define DEMANGLE_UTILITY_H
#include "StringView.h"
-
#include <cstdint>
#include <cstdlib>
#include <cstring>
#include <iterator>
#include <limits>
+DEMANGLE_NAMESPACE_BEGIN
+
// Stream that AST nodes write their string representation into after the AST
// has been parsed.
class OutputStream {
@@ -184,4 +187,6 @@
return true;
}
+DEMANGLE_NAMESPACE_END
+
#endif
diff --git a/lib/Demangle/MicrosoftDemangle.cpp b/lib/Demangle/MicrosoftDemangle.cpp
index 51ffa0b..9db2f91 100644
--- a/lib/Demangle/MicrosoftDemangle.cpp
+++ b/lib/Demangle/MicrosoftDemangle.cpp
@@ -18,7 +18,7 @@
#include "llvm/Demangle/Demangle.h"
#include "llvm/Demangle/MicrosoftDemangleNodes.h"
-#include "llvm/Demangle/Compiler.h"
+#include "llvm/Demangle/DemangleConfig.h"
#include "llvm/Demangle/StringView.h"
#include "llvm/Demangle/Utility.h"
@@ -265,7 +265,7 @@
NI->Name = "`RTTI Complete Object Locator'";
break;
default:
- LLVM_BUILTIN_UNREACHABLE;
+ DEMANGLE_UNREACHABLE;
}
QualifiedNameNode *QN = demangleNameScopeChain(MangledName, NI);
SpecialTableSymbolNode *STSN = Arena.alloc<SpecialTableSymbolNode>();
@@ -632,7 +632,7 @@
case FunctionIdentifierCodeGroup::DoubleUnder:
return DoubleUnder[Index];
}
- LLVM_BUILTIN_UNREACHABLE;
+ DEMANGLE_UNREACHABLE;
}
IdentifierNode *
@@ -1188,7 +1188,7 @@
switch (MangledName.popFront()) {
case '1':
IsWcharT = true;
- LLVM_FALLTHROUGH;
+ DEMANGLE_FALLTHROUGH;
case '0':
break;
default:
@@ -1255,7 +1255,7 @@
Result->Char = CharKind::Char32;
break;
default:
- LLVM_BUILTIN_UNREACHABLE;
+ DEMANGLE_UNREACHABLE;
}
const unsigned NumChars = BytesDecoded / CharBytes;
for (unsigned CharIndex = 0; CharIndex < NumChars; ++CharIndex) {
@@ -2083,15 +2083,15 @@
case 'J':
TPRN->ThunkOffsets[TPRN->ThunkOffsetCount++] =
demangleSigned(MangledName);
- LLVM_FALLTHROUGH;
+ DEMANGLE_FALLTHROUGH;
case 'I':
TPRN->ThunkOffsets[TPRN->ThunkOffsetCount++] =
demangleSigned(MangledName);
- LLVM_FALLTHROUGH;
+ DEMANGLE_FALLTHROUGH;
case 'H':
TPRN->ThunkOffsets[TPRN->ThunkOffsetCount++] =
demangleSigned(MangledName);
- LLVM_FALLTHROUGH;
+ DEMANGLE_FALLTHROUGH;
case '1':
break;
default:
@@ -2117,13 +2117,13 @@
case 'G':
TPRN->ThunkOffsets[TPRN->ThunkOffsetCount++] =
demangleSigned(MangledName);
- LLVM_FALLTHROUGH;
+ DEMANGLE_FALLTHROUGH;
case 'F':
TPRN->ThunkOffsets[TPRN->ThunkOffsetCount++] =
demangleSigned(MangledName);
TPRN->ThunkOffsets[TPRN->ThunkOffsetCount++] =
demangleSigned(MangledName);
- LLVM_FALLTHROUGH;
+ DEMANGLE_FALLTHROUGH;
case '0':
break;
default:
diff --git a/lib/Demangle/MicrosoftDemangleNodes.cpp b/lib/Demangle/MicrosoftDemangleNodes.cpp
index 622f8e7..e94d237 100644
--- a/lib/Demangle/MicrosoftDemangleNodes.cpp
+++ b/lib/Demangle/MicrosoftDemangleNodes.cpp
@@ -12,7 +12,7 @@
//===----------------------------------------------------------------------===//
#include "llvm/Demangle/MicrosoftDemangleNodes.h"
-#include "llvm/Demangle/Compiler.h"
+#include "llvm/Demangle/DemangleConfig.h"
#include "llvm/Demangle/Utility.h"
#include <cctype>
#include <string>
diff --git a/lib/Support/ItaniumManglingCanonicalizer.cpp b/lib/Support/ItaniumManglingCanonicalizer.cpp
index e55dcd7..24e600a 100644
--- a/lib/Support/ItaniumManglingCanonicalizer.cpp
+++ b/lib/Support/ItaniumManglingCanonicalizer.cpp
@@ -22,6 +22,7 @@
using llvm::itanium_demangle::ForwardTemplateReference;
using llvm::itanium_demangle::Node;
using llvm::itanium_demangle::NodeKind;
+using llvm::itanium_demangle::StringView;
namespace {
struct FoldingSetNodeIDBuilder {
