[llvm] Weak linkage emulation (PR #128486)
Lang Hames via llvm-commits
llvm-commits at lists.llvm.org
Mon Feb 24 02:05:44 PST 2025
https://github.com/lhames created https://github.com/llvm/llvm-project/pull/128486
None
>From 872db7de475db305cb5bfc6e0e87f2f913458851 Mon Sep 17 00:00:00 2001
From: Lang Hames <lhames at gmail.com>
Date: Sun, 23 Feb 2025 19:32:27 +1100
Subject: [PATCH 1/2] [ORC] Remove unused header. NFC.
---
.../Orc/JITLinkLazyCallThroughManager.h | 26 -------------------
1 file changed, 26 deletions(-)
delete mode 100644 llvm/include/llvm/ExecutionEngine/Orc/JITLinkLazyCallThroughManager.h
diff --git a/llvm/include/llvm/ExecutionEngine/Orc/JITLinkLazyCallThroughManager.h b/llvm/include/llvm/ExecutionEngine/Orc/JITLinkLazyCallThroughManager.h
deleted file mode 100644
index 19075c76a6073..0000000000000
--- a/llvm/include/llvm/ExecutionEngine/Orc/JITLinkLazyCallThroughManager.h
+++ /dev/null
@@ -1,26 +0,0 @@
-//===- JITLinkLazyCallThroughManager.h - JITLink based laziness -*- C++ -*-===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-//
-// Redirectable Symbol Manager implementation using JITLink
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef LLVM_EXECUTIONENGINE_ORC_JITLINKLAZYCALLTHROUGHMANAGER_H
-#define LLVM_EXECUTIONENGINE_ORC_JITLINKLAZYCALLTHROUGHMANAGER_H
-
-#include "llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h"
-#include "llvm/ExecutionEngine/Orc/RedirectionManager.h"
-#include "llvm/Support/StringSaver.h"
-
-#include <atomic>
-
-namespace llvm {
-namespace orc {} // namespace orc
-} // namespace llvm
-
-#endif // LLVM_EXECUTIONENGINE_ORC_JITLINKLAZYCALLTHROUGHMANAGER_H
>From 9ba85d114c0480aa37ab1cb5e0acf7ef03036b6b Mon Sep 17 00:00:00 2001
From: Lang Hames <lhames at gmail.com>
Date: Mon, 24 Feb 2025 17:14:58 +1100
Subject: [PATCH 2/2] [ORC][llvm-jitlink] Add support for emulating ld64
-weak-lx / -weak_library.
Linking libraries in ld64 with -weak-lx / -weak_library causes all references
to symbols in those libraries to be made weak, allowing the librarie to be
missing at runtime.
This patch extends EPCDynamicLibrarySearchGenerator with support for emulating
this behavior: If an instance is constructed with an Allow predicate but no
dylib handle then all symbols matching the predicate are immediately resolved
to null.
The llvm-jitlink tool is updated with -weak-lx / -weak_library options for
testing. Unlike their ld64 counterparts these options take a TBD file as input,
and always resolve all exports in the TBD file to null.
---
.../Orc/EPCDynamicLibrarySearchGenerator.h | 17 +++-
.../ExecutionEngine/Orc/GetTapiInterface.h | 28 ++++++
llvm/lib/ExecutionEngine/Orc/CMakeLists.txt | 1 +
.../Orc/EPCDynamicLibrarySearchGenerator.cpp | 24 ++++-
.../ExecutionEngine/Orc/GetTapiInterface.cpp | 39 ++++++++
.../JITLink/AArch64/Inputs/MachO_Foo.tbd | 23 +++++
.../AArch64/Inputs/MachO_main_ret_foo.s | 15 +++
.../JITLink/AArch64/MachO_weak_link.test | 8 ++
llvm/tools/llvm-jitlink/llvm-jitlink.cpp | 92 ++++++++++++++++++-
9 files changed, 241 insertions(+), 6 deletions(-)
create mode 100644 llvm/include/llvm/ExecutionEngine/Orc/GetTapiInterface.h
create mode 100644 llvm/lib/ExecutionEngine/Orc/GetTapiInterface.cpp
create mode 100644 llvm/test/ExecutionEngine/JITLink/AArch64/Inputs/MachO_Foo.tbd
create mode 100644 llvm/test/ExecutionEngine/JITLink/AArch64/Inputs/MachO_main_ret_foo.s
create mode 100644 llvm/test/ExecutionEngine/JITLink/AArch64/MachO_weak_link.test
diff --git a/llvm/include/llvm/ExecutionEngine/Orc/EPCDynamicLibrarySearchGenerator.h b/llvm/include/llvm/ExecutionEngine/Orc/EPCDynamicLibrarySearchGenerator.h
index 6571a70da9ba7..cb05d7236a7e3 100644
--- a/llvm/include/llvm/ExecutionEngine/Orc/EPCDynamicLibrarySearchGenerator.h
+++ b/llvm/include/llvm/ExecutionEngine/Orc/EPCDynamicLibrarySearchGenerator.h
@@ -43,6 +43,19 @@ class EPCDynamicLibrarySearchGenerator : public DefinitionGenerator {
: EPC(ES.getExecutorProcessControl()), H(H), Allow(std::move(Allow)),
AddAbsoluteSymbols(std::move(AddAbsoluteSymbols)) {}
+ /// Create an EPCDynamicLibrarySearchGenerator that resolves all symbols
+ /// matching the Allow predicate to null. This can be used to emulate linker
+ /// options like -weak-l / -weak_library where the library is missing at
+ /// runtime. (Note: here we're explicitly returning null for these symbols,
+ /// rather than returning no value at all for them, which is the usual
+ /// "missing symbol" behavior in ORC. This distinction shouldn't matter for
+ /// most use-cases).
+ EPCDynamicLibrarySearchGenerator(
+ ExecutionSession &ES, SymbolPredicate Allow,
+ AddAbsoluteSymbolsFn AddAbsoluteSymbols = nullptr)
+ : EPC(ES.getExecutorProcessControl()), Allow(std::move(Allow)),
+ AddAbsoluteSymbols(std::move(AddAbsoluteSymbols)) {}
+
/// Permanently loads the library at the given path and, on success, returns
/// an EPCDynamicLibrarySearchGenerator that will search it for symbol
/// definitions in the library. On failure returns the reason the library
@@ -66,8 +79,10 @@ class EPCDynamicLibrarySearchGenerator : public DefinitionGenerator {
const SymbolLookupSet &Symbols) override;
private:
+ Error addAbsolutes(JITDylib &JD, SymbolMap Symbols);
+
ExecutorProcessControl &EPC;
- tpctypes::DylibHandle H;
+ std::optional<tpctypes::DylibHandle> H;
SymbolPredicate Allow;
AddAbsoluteSymbolsFn AddAbsoluteSymbols;
};
diff --git a/llvm/include/llvm/ExecutionEngine/Orc/GetTapiInterface.h b/llvm/include/llvm/ExecutionEngine/Orc/GetTapiInterface.h
new file mode 100644
index 0000000000000..36e943808e530
--- /dev/null
+++ b/llvm/include/llvm/ExecutionEngine/Orc/GetTapiInterface.h
@@ -0,0 +1,28 @@
+//===---- GetTapiInterface.h -- Get interface from TAPI file ----*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Get symbol interface from TAPI file.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_EXECUTIONENGINE_ORC_GETTAPIINTERFACE_H
+#define LLVM_EXECUTIONENGINE_ORC_GETTAPIINTERFACE_H
+
+#include "llvm/ExecutionEngine/Orc/Core.h"
+#include "llvm/Object/TapiUniversal.h"
+
+namespace llvm::orc {
+
+/// Returns a SymbolNameSet containing the exported symbols defined in the
+/// relevant slice of the TapiUniversal file.
+Expected<SymbolNameSet> getInterfaceFromTapiFile(ExecutionSession &ES,
+ object::TapiUniversal &TU);
+
+} // namespace llvm::orc
+
+#endif // LLVM_EXECUTIONENGINE_ORC_GETTAPIINTERFACE_H
diff --git a/llvm/lib/ExecutionEngine/Orc/CMakeLists.txt b/llvm/lib/ExecutionEngine/Orc/CMakeLists.txt
index 8a866294eee25..ced3aa0e1ae62 100644
--- a/llvm/lib/ExecutionEngine/Orc/CMakeLists.txt
+++ b/llvm/lib/ExecutionEngine/Orc/CMakeLists.txt
@@ -25,6 +25,7 @@ add_llvm_component_library(LLVMOrcJIT
EPCIndirectionUtils.cpp
ExecutionUtils.cpp
ObjectFileInterface.cpp
+ GetTapiInterface.cpp
IndirectionUtils.cpp
IRCompileLayer.cpp
IRTransformLayer.cpp
diff --git a/llvm/lib/ExecutionEngine/Orc/EPCDynamicLibrarySearchGenerator.cpp b/llvm/lib/ExecutionEngine/Orc/EPCDynamicLibrarySearchGenerator.cpp
index 2a93fcbf6c8c8..59d66b271bb09 100644
--- a/llvm/lib/ExecutionEngine/Orc/EPCDynamicLibrarySearchGenerator.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/EPCDynamicLibrarySearchGenerator.cpp
@@ -42,6 +42,18 @@ Error EPCDynamicLibrarySearchGenerator::tryToGenerate(
<< Symbols << "\n";
});
+ // If there's no handle then resolve all requested symbols to null.
+ if (!H) {
+ assert(Allow && "No handle or filter?");
+ SymbolMap Nulls;
+ for (auto &[Name, LookupFlags] : Symbols) {
+ if (Allow(Name))
+ Nulls[Name] = {};
+ }
+ return addAbsolutes(JD, std::move(Nulls));
+ }
+
+ // Otherwise proceed with lookup in the remote.
SymbolLookupSet LookupSymbols;
for (auto &KV : Symbols) {
@@ -51,7 +63,7 @@ Error EPCDynamicLibrarySearchGenerator::tryToGenerate(
LookupSymbols.add(KV.first, SymbolLookupFlags::WeaklyReferencedSymbol);
}
- DylibManager::LookupRequest Request(H, LookupSymbols);
+ DylibManager::LookupRequest Request(*H, LookupSymbols);
// Copy-capture LookupSymbols, since LookupRequest keeps a reference.
EPC.getDylibMgr().lookupSymbolsAsync(Request, [this, &JD, LS = std::move(LS),
LookupSymbols](
@@ -85,9 +97,7 @@ Error EPCDynamicLibrarySearchGenerator::tryToGenerate(
return LS.continueLookup(Error::success());
// Define resolved symbols.
- Error Err = AddAbsoluteSymbols
- ? AddAbsoluteSymbols(JD, std::move(NewSymbols))
- : JD.define(absoluteSymbols(std::move(NewSymbols)));
+ Error Err = addAbsolutes(JD, std::move(NewSymbols));
LS.continueLookup(std::move(Err));
});
@@ -95,5 +105,11 @@ Error EPCDynamicLibrarySearchGenerator::tryToGenerate(
return Error::success();
}
+Error EPCDynamicLibrarySearchGenerator::addAbsolutes(JITDylib &JD,
+ SymbolMap Symbols) {
+ return AddAbsoluteSymbols ? AddAbsoluteSymbols(JD, std::move(Symbols))
+ : JD.define(absoluteSymbols(std::move(Symbols)));
+}
+
} // end namespace orc
} // end namespace llvm
diff --git a/llvm/lib/ExecutionEngine/Orc/GetTapiInterface.cpp b/llvm/lib/ExecutionEngine/Orc/GetTapiInterface.cpp
new file mode 100644
index 0000000000000..f74db3e7dd85a
--- /dev/null
+++ b/llvm/lib/ExecutionEngine/Orc/GetTapiInterface.cpp
@@ -0,0 +1,39 @@
+//===--------- GetTapiInterface.cpp - Get interface from TAPI file --------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ExecutionEngine/Orc/GetTapiInterface.h"
+
+#define DEBUG_TYPE "orc"
+
+namespace llvm::orc {
+
+Expected<SymbolNameSet> getInterfaceFromTapiFile(ExecutionSession &ES,
+ object::TapiUniversal &TU) {
+ SymbolNameSet Symbols;
+
+ auto CPUType = MachO::getCPUType(ES.getTargetTriple());
+ if (!CPUType)
+ return CPUType.takeError();
+
+ auto CPUSubType = MachO::getCPUSubType(ES.getTargetTriple());
+ if (!CPUSubType)
+ return CPUSubType.takeError();
+
+ auto &TUIF = TU.getInterfaceFile();
+ auto ArchInterface =
+ TUIF.extract(MachO::getArchitectureFromCpuType(*CPUType, *CPUSubType));
+ if (!ArchInterface)
+ return ArchInterface.takeError();
+
+ for (auto *Sym : (*ArchInterface)->exports())
+ Symbols.insert(ES.intern(Sym->getName()));
+
+ return Symbols;
+}
+
+} // namespace llvm::orc
diff --git a/llvm/test/ExecutionEngine/JITLink/AArch64/Inputs/MachO_Foo.tbd b/llvm/test/ExecutionEngine/JITLink/AArch64/Inputs/MachO_Foo.tbd
new file mode 100644
index 0000000000000..54de369194a91
--- /dev/null
+++ b/llvm/test/ExecutionEngine/JITLink/AArch64/Inputs/MachO_Foo.tbd
@@ -0,0 +1,23 @@
+--- !tapi-tbd
+tbd-version: 4
+targets: [ arm64-macos ]
+uuids:
+ - target: arm64-macos
+ value: 00000000-0000-0000-0000-000000000000
+flags: [ installapi ]
+install-name: Foo.framework/Foo
+current-version: 1.2.3
+compatibility-version: 1.2
+swift-abi-version: 5
+parent-umbrella:
+ - targets: [ arm64-macos ]
+ umbrella: System
+exports:
+ - targets: [ arm64-macos ]
+ symbols: [ _foo ]
+ objc-classes: []
+ objc-eh-types: []
+ objc-ivars: []
+ weak-symbols: []
+ thread-local-symbols: []
+...
diff --git a/llvm/test/ExecutionEngine/JITLink/AArch64/Inputs/MachO_main_ret_foo.s b/llvm/test/ExecutionEngine/JITLink/AArch64/Inputs/MachO_main_ret_foo.s
new file mode 100644
index 0000000000000..9037ead6fc762
--- /dev/null
+++ b/llvm/test/ExecutionEngine/JITLink/AArch64/Inputs/MachO_main_ret_foo.s
@@ -0,0 +1,15 @@
+ .section __TEXT,__text,regular,pure_instructions
+ .globl _main
+ .p2align 2
+_main:
+ .cfi_startproc
+Lloh0:
+ adrp x0, _foo at GOTPAGE
+Lloh1:
+ ldr x0, [x0, _foo at GOTPAGEOFF]
+
+ ret
+ .loh AdrpLdrGot Lloh0, Lloh1
+ .cfi_endproc
+
+.subsections_via_symbols
diff --git a/llvm/test/ExecutionEngine/JITLink/AArch64/MachO_weak_link.test b/llvm/test/ExecutionEngine/JITLink/AArch64/MachO_weak_link.test
new file mode 100644
index 0000000000000..4326a604297b6
--- /dev/null
+++ b/llvm/test/ExecutionEngine/JITLink/AArch64/MachO_weak_link.test
@@ -0,0 +1,8 @@
+# RUN: rm -rf %t && mkdir -p %t
+# RUN: llvm-mc -triple=arm64-apple-darwin19 -filetype=obj -o %t/main.o \
+# RUN: %S/Inputs/MachO_main_ret_foo.s
+# RUN: llvm-jitlink -noexec %t/main.o -weak_library %S/Inputs/MachO_Foo.tbd
+
+# Check that we can load main.o, which unconditionally uses symbol foo, by
+# using -weak_library on a TBD file to emulate forced weak linking against
+# a library that supplies foo, but is missing at runtime.
diff --git a/llvm/tools/llvm-jitlink/llvm-jitlink.cpp b/llvm/tools/llvm-jitlink/llvm-jitlink.cpp
index 0421b86480254..81d5fe03419c0 100644
--- a/llvm/tools/llvm-jitlink/llvm-jitlink.cpp
+++ b/llvm/tools/llvm-jitlink/llvm-jitlink.cpp
@@ -29,6 +29,7 @@
#include "llvm/ExecutionEngine/Orc/EPCDynamicLibrarySearchGenerator.h"
#include "llvm/ExecutionEngine/Orc/EPCEHFrameRegistrar.h"
#include "llvm/ExecutionEngine/Orc/ExecutionUtils.h"
+#include "llvm/ExecutionEngine/Orc/GetTapiInterface.h"
#include "llvm/ExecutionEngine/Orc/IndirectionUtils.h"
#include "llvm/ExecutionEngine/Orc/JITLinkRedirectableSymbolManager.h"
#include "llvm/ExecutionEngine/Orc/JITLinkReentryTrampolines.h"
@@ -58,6 +59,7 @@
#include "llvm/Object/COFF.h"
#include "llvm/Object/MachO.h"
#include "llvm/Object/ObjectFile.h"
+#include "llvm/Object/TapiUniversal.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/InitLLVM.h"
@@ -140,6 +142,20 @@ static cl::list<std::string>
cl::desc("Link against library X with hidden visibility"),
cl::cat(JITLinkCategory));
+static cl::list<std::string>
+ LibrariesWeak("weak-l",
+ cl::desc("Emulate weak link against library X. Must resolve "
+ "to a TextAPI file, and all symbols in the "
+ "interface will resolve to null."),
+ cl::Prefix, cl::cat(JITLinkCategory));
+
+static cl::list<std::string> WeakLibraries(
+ "weak_library",
+ cl::desc("Emulate weak link against library X. X must point to a "
+ "TextAPI file, and all symbols in the interface will "
+ "resolve to null"),
+ cl::cat(JITLinkCategory));
+
static cl::opt<bool> SearchSystemLibrary(
"search-sys-lib",
cl::desc("Add system library paths to library search paths"),
@@ -2100,6 +2116,27 @@ static SmallVector<StringRef, 5> getSearchPathsFromEnvVar(Session &S) {
return PathVec;
}
+static Expected<std::unique_ptr<DefinitionGenerator>>
+LoadLibraryWeak(Session &S, StringRef InterfacePath) {
+ auto TapiFileBuffer = getFile(InterfacePath);
+ if (!TapiFileBuffer)
+ return TapiFileBuffer.takeError();
+
+ auto Tapi =
+ object::TapiUniversal::create((*TapiFileBuffer)->getMemBufferRef());
+ if (!Tapi)
+ return Tapi.takeError();
+
+ auto Symbols = getInterfaceFromTapiFile(S.ES, **Tapi);
+ if (!Symbols)
+ return Symbols.takeError();
+
+ return std::make_unique<EPCDynamicLibrarySearchGenerator>(
+ S.ES, [Symbols = std::move(*Symbols)](const SymbolStringPtr &Sym) {
+ return Symbols.count(Sym);
+ });
+}
+
static Error addLibraries(Session &S,
const std::map<unsigned, JITDylib *> &IdxToJD,
const DenseSet<unsigned> &LazyLinkIdxs) {
@@ -2142,11 +2179,12 @@ static Error addLibraries(Session &S,
bool IsPath = false;
unsigned Position;
ArrayRef<StringRef> CandidateExtensions;
- enum { Standard, Hidden } Modifier;
+ enum { Standard, Hidden, Weak } Modifier;
};
// Queue to load library as in the order as it appears in the argument list.
std::deque<LibraryLoad> LibraryLoadQueue;
+
// Add archive files from the inputs to LibraryLoads.
for (auto InputFileItr = InputFiles.begin(), InputFileEnd = InputFiles.end();
InputFileItr != InputFileEnd; ++InputFileItr) {
@@ -2173,9 +2211,23 @@ static Error addLibraries(Session &S,
LL.Modifier = LibraryLoad::Hidden;
LibraryLoadQueue.push_back(std::move(LL));
}
+
+ // Add -weak_library arguments to LibraryLoads.
+ for (auto LibItr = WeakLibraries.begin(), LibEnd = WeakLibraries.end();
+ LibItr != LibEnd; ++LibItr) {
+ LibraryLoad LL;
+ LL.LibName = *LibItr;
+ LL.IsPath = true;
+ LL.Position = WeakLibraries.getPosition(LibItr - WeakLibraries.begin());
+ LL.CandidateExtensions = {};
+ LL.Modifier = LibraryLoad::Weak;
+ LibraryLoadQueue.push_back(std::move(LL));
+ }
+
StringRef StandardExtensions[] = {".so", ".dylib", ".dll", ".a", ".lib"};
StringRef DynLibExtensionsOnly[] = {".so", ".dylib", ".dll"};
StringRef ArchiveExtensionsOnly[] = {".a", ".lib"};
+ StringRef InterfaceExtensionsOnly = {".tbd"};
// Add -lx arguments to LibraryLoads.
for (auto LibItr = Libraries.begin(), LibEnd = Libraries.end();
@@ -2201,6 +2253,18 @@ static Error addLibraries(Session &S,
LibraryLoadQueue.push_back(std::move(LL));
}
+ // Add -weak-lx arguments to LibraryLoads.
+ for (auto LibWeakItr = LibrariesWeak.begin(),
+ LibWeakEnd = LibrariesWeak.end();
+ LibWeakItr != LibWeakEnd; ++LibWeakItr) {
+ LibraryLoad LL;
+ LL.LibName = *LibWeakItr;
+ LL.Position = LibrariesWeak.getPosition(LibWeakItr - LibrariesWeak.begin());
+ LL.CandidateExtensions = InterfaceExtensionsOnly;
+ LL.Modifier = LibraryLoad::Weak;
+ LibraryLoadQueue.push_back(std::move(LL));
+ }
+
// Sort library loads by position in the argument list.
llvm::sort(LibraryLoadQueue,
[](const LibraryLoad &LHS, const LibraryLoad &RHS) {
@@ -2220,6 +2284,9 @@ static Error addLibraries(Session &S,
GetObjFileInterface = getObjectFileInterfaceHidden;
S.HiddenArchives.insert(Path);
break;
+ case LibraryLoad::Weak:
+ llvm_unreachable("Unsupported");
+ break;
}
auto &LinkLayer = S.getLinkLayer(LazyLinkIdxs.count(LL.Position));
@@ -2266,11 +2333,26 @@ static Error addLibraries(Session &S,
// If this is the name of a JITDylib then link against that.
if (auto *LJD = S.ES.getJITDylibByName(LL.LibName)) {
+ if (LL.Modifier == LibraryLoad::Weak)
+ return make_error<StringError>(
+ "Can't use -weak-lx or -weak_library to load JITDylib " +
+ LL.LibName,
+ inconvertibleErrorCode());
JD.addToLinkOrder(*LJD);
continue;
}
if (LL.IsPath) {
+ // Must be -weak_library.
+ if (LL.Modifier == LibraryLoad::Weak) {
+ if (auto G = LoadLibraryWeak(S, LL.LibName)) {
+ JD.addGenerator(std::move(*G));
+ continue;
+ } else
+ return G.takeError();
+ }
+
+ // Otherwise handle archive.
auto G = AddArchive(JD, LL.LibName.c_str(), LL);
if (!G)
return createFileError(LL.LibName, G.takeError());
@@ -2337,6 +2419,14 @@ static Error addLibraries(Session &S,
});
break;
}
+ case file_magic::tapi_file:
+ assert(LL.Modifier == LibraryLoad::Weak &&
+ "TextAPI file not being loaded as weak?");
+ if (auto G = LoadLibraryWeak(S, LibPath.data()))
+ JD.addGenerator(std::move(*G));
+ else
+ return G.takeError();
+ break;
default:
// This file isn't a recognized library kind.
LLVM_DEBUG({
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