[llvm] e2eaf8d - [ORC] Force eh-frame use for older Darwins on x86-64 in MachOPlatform, LLJIT.
Lang Hames via llvm-commits
llvm-commits at lists.llvm.org
Thu Feb 6 22:04:15 PST 2025
Author: Lang Hames
Date: 2025-02-07T17:04:05+11:00
New Revision: e2eaf8ded78507100513a17e8193e2c4b094f8da
URL: https://github.com/llvm/llvm-project/commit/e2eaf8ded78507100513a17e8193e2c4b094f8da
DIFF: https://github.com/llvm/llvm-project/commit/e2eaf8ded78507100513a17e8193e2c4b094f8da.diff
LOG: [ORC] Force eh-frame use for older Darwins on x86-64 in MachOPlatform, LLJIT.
The system libunwind on older Darwins does not support JIT registration of
compact-unwind. Since the CompactUnwindManager utility discards redundant
eh-frame FDEs by default we need to remove the compact-unwind section first
when targeting older libunwinds in order to preserve eh-frames.
While LLJIT was already doing this as of eae6d6d18bd, MachOPlatform was not.
This was causing buildbot failures in the ORC runtime (e.g. in
https://green.lab.llvm.org/job/llvm.org/job/clang-stage1-RA/3479/).
This patch updates both LLJIT and MachOPlatform to check a bootstrap value,
"darwin-use-ehframes-only", to determine whether to forcibly preserve
eh-frame sections. If this value is present and set to true then compact-unwind
sections will be discarded, causing eh-frames to be preserved. If the value is
absent or set to false then compact-unwind will be used and redundant FDEs in
eh-frames discarded (FDEs that are needed by the compact-unwind section are
always preserved).
rdar://143895614
Added:
llvm/include/llvm/ExecutionEngine/Orc/TargetProcess/DefaultHostBootstrapValues.h
llvm/lib/ExecutionEngine/Orc/TargetProcess/DefaultHostBootstrapValues.cpp
Modified:
llvm/include/llvm/ExecutionEngine/Orc/MachOPlatform.h
llvm/lib/ExecutionEngine/Orc/ExecutorProcessControl.cpp
llvm/lib/ExecutionEngine/Orc/LLJIT.cpp
llvm/lib/ExecutionEngine/Orc/MachOPlatform.cpp
llvm/lib/ExecutionEngine/Orc/TargetProcess/CMakeLists.txt
llvm/lib/ExecutionEngine/Orc/TargetProcess/OrcRTBootstrap.cpp
llvm/tools/llvm-jitlink/llvm-jitlink-executor/llvm-jitlink-executor.cpp
Removed:
################################################################################
diff --git a/llvm/include/llvm/ExecutionEngine/Orc/MachOPlatform.h b/llvm/include/llvm/ExecutionEngine/Orc/MachOPlatform.h
index 6e99f6c03a7c676..91842714f6c4c38 100644
--- a/llvm/include/llvm/ExecutionEngine/Orc/MachOPlatform.h
+++ b/llvm/include/llvm/ExecutionEngine/Orc/MachOPlatform.h
@@ -368,6 +368,7 @@ class MachOPlatform : public Platform {
DenseMap<JITDylib *, SymbolLookupSet> RegisteredInitSymbols;
std::mutex PlatformMutex;
+ bool ForceEHFrames = false;
BootstrapInfo *Bootstrap = nullptr;
DenseMap<JITDylib *, ExecutorAddr> JITDylibToHeaderAddr;
DenseMap<ExecutorAddr, JITDylib *> HeaderAddrToJITDylib;
diff --git a/llvm/include/llvm/ExecutionEngine/Orc/TargetProcess/DefaultHostBootstrapValues.h b/llvm/include/llvm/ExecutionEngine/Orc/TargetProcess/DefaultHostBootstrapValues.h
new file mode 100644
index 000000000000000..d3277e61eeb7b12
--- /dev/null
+++ b/llvm/include/llvm/ExecutionEngine/Orc/TargetProcess/DefaultHostBootstrapValues.h
@@ -0,0 +1,28 @@
+//===- DefaultHostBootstrapValues.h - Defaults for host process -*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// Set sensible default bootstrap values for JIT execution in the host process.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_EXECUTIONENGINE_ORC_TARGETPROCESS_DEFAULTHOSTBOOTSTRAPVALUES_H
+#define LLVM_EXECUTIONENGINE_ORC_TARGETPROCESS_DEFAULTHOSTBOOTSTRAPVALUES_H
+
+#include "llvm/ADT/StringMap.h"
+#include "llvm/ExecutionEngine/Orc/Shared/ExecutorAddress.h"
+#include <vector>
+
+namespace llvm::orc {
+
+void addDefaultBootstrapValuesForHostProcess(
+ StringMap<std::vector<char>> &BootstrapMap,
+ StringMap<ExecutorAddr> &BootstrapSymbols);
+
+} // namespace llvm::orc
+
+#endif // LLVM_EXECUTIONENGINE_ORC_TARGETPROCESS_DEFAULTHOSTBOOTSTRAPVALUES_H
diff --git a/llvm/lib/ExecutionEngine/Orc/ExecutorProcessControl.cpp b/llvm/lib/ExecutionEngine/Orc/ExecutorProcessControl.cpp
index a9dbcd166117b0c..7b38150ab4b650b 100644
--- a/llvm/lib/ExecutionEngine/Orc/ExecutorProcessControl.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/ExecutorProcessControl.cpp
@@ -9,8 +9,7 @@
#include "llvm/ExecutionEngine/Orc/ExecutorProcessControl.h"
#include "llvm/ExecutionEngine/Orc/Core.h"
-#include "llvm/ExecutionEngine/Orc/Shared/OrcRTBridge.h"
-#include "llvm/ExecutionEngine/Orc/TargetProcess/RegisterEHFrames.h"
+#include "llvm/ExecutionEngine/Orc/TargetProcess/DefaultHostBootstrapValues.h"
#include "llvm/ExecutionEngine/Orc/TargetProcess/TargetExecutionUtils.h"
#include "llvm/Support/Process.h"
#include "llvm/TargetParser/Host.h"
@@ -49,10 +48,7 @@ SelfExecutorProcessControl::SelfExecutorProcessControl(
if (this->TargetTriple.isOSBinFormatMachO())
GlobalManglingPrefix = '_';
- this->BootstrapSymbols[rt::RegisterEHFrameSectionWrapperName] =
- ExecutorAddr::fromPtr(&llvm_orc_registerEHFrameSectionWrapper);
- this->BootstrapSymbols[rt::DeregisterEHFrameSectionWrapperName] =
- ExecutorAddr::fromPtr(&llvm_orc_deregisterEHFrameSectionWrapper);
+ addDefaultBootstrapValuesForHostProcess(BootstrapMap, BootstrapSymbols);
#ifdef __APPLE__
// FIXME: Don't add an UnwindInfoManager by default -- it's redundant when
diff --git a/llvm/lib/ExecutionEngine/Orc/LLJIT.cpp b/llvm/lib/ExecutionEngine/Orc/LLJIT.cpp
index 938fe58ef85cfeb..dd844ae3a42bc88 100644
--- a/llvm/lib/ExecutionEngine/Orc/LLJIT.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/LLJIT.cpp
@@ -1221,22 +1221,37 @@ Expected<JITDylibSP> setUpGenericLLVMIRPlatform(LLJIT &J) {
if (auto *OLL = dyn_cast<ObjectLinkingLayer>(&J.getObjLinkingLayer())) {
- bool CompactUnwindInfoSupported = false;
+ bool UseEHFrames = true;
// Enable compact-unwind support if possible.
if (J.getTargetTriple().isOSDarwin() ||
J.getTargetTriple().isOSBinFormatMachO()) {
- if (auto UIRP = UnwindInfoRegistrationPlugin::Create(
- J.getIRCompileLayer(), PlatformJD)) {
- CompactUnwindInfoSupported = true;
- OLL->addPlugin(std::move(*UIRP));
- LLVM_DEBUG(dbgs() << "Enabled compact-unwind support.\n");
- } else
- consumeError(UIRP.takeError());
+
+ // Check if the bootstrap map says that we should force eh-frames:
+ // Older libunwinds require this as they don't have a dynamic
+ // registration API for compact-unwind.
+ std::optional<bool> ForceEHFrames;
+ if (auto Err = J.getExecutionSession().getBootstrapMapValue<bool, bool>(
+ "darwin-use-ehframes-only", ForceEHFrames))
+ return Err;
+ if (ForceEHFrames.has_value())
+ UseEHFrames = *ForceEHFrames;
+ else
+ UseEHFrames = false;
+
+ // If UseEHFrames hasn't been set then we're good to use compact-unwind.
+ if (!UseEHFrames) {
+ if (auto UIRP = UnwindInfoRegistrationPlugin::Create(
+ J.getIRCompileLayer(), PlatformJD)) {
+ OLL->addPlugin(std::move(*UIRP));
+ LLVM_DEBUG(dbgs() << "Enabled compact-unwind support.\n");
+ } else
+ return UIRP.takeError();
+ }
}
// Otherwise fall back to standard unwind registration.
- if (!CompactUnwindInfoSupported) {
+ if (UseEHFrames) {
auto &ES = J.getExecutionSession();
if (auto EHFrameRegistrar = EPCEHFrameRegistrar::Create(ES)) {
OLL->addPlugin(std::make_unique<EHFrameRegistrationPlugin>(
diff --git a/llvm/lib/ExecutionEngine/Orc/MachOPlatform.cpp b/llvm/lib/ExecutionEngine/Orc/MachOPlatform.cpp
index 845990d965b16d3..d4e341a96f5b1f8 100644
--- a/llvm/lib/ExecutionEngine/Orc/MachOPlatform.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/MachOPlatform.cpp
@@ -481,6 +481,15 @@ MachOPlatform::MachOPlatform(
ObjLinkingLayer.addPlugin(std::make_unique<MachOPlatformPlugin>(*this));
PlatformJD.addGenerator(std::move(OrcRuntimeGenerator));
+ {
+ // Check for force-eh-frame
+ std::optional<bool> ForceEHFrames;
+ if ((Err = ES.getBootstrapMapValue<bool, bool>("darwin-use-ehframes-only",
+ ForceEHFrames)))
+ return;
+ this->ForceEHFrames = ForceEHFrames.has_value() ? *ForceEHFrames : false;
+ }
+
BootstrapInfo BI;
Bootstrap = &BI;
@@ -811,6 +820,12 @@ void MachOPlatform::MachOPlatformPlugin::modifyPassConfig(
HeaderAddr = I->second;
}
+ // If we're forcing eh-frame use then discard the compact-unwind section
+ // immediately to prevent FDEs from being stripped.
+ if (MP.ForceEHFrames)
+ if (auto *CUSec = LG.findSectionByName(MachOCompactUnwindSectionName))
+ LG.removeSection(*CUSec);
+
// Point the libunwind dso-base absolute symbol at the header for the
// JITDylib. This will prevent us from synthesizing a new header for
// every object.
diff --git a/llvm/lib/ExecutionEngine/Orc/TargetProcess/CMakeLists.txt b/llvm/lib/ExecutionEngine/Orc/TargetProcess/CMakeLists.txt
index 1d29a89d5eb0945..9f3abac156adb12 100644
--- a/llvm/lib/ExecutionEngine/Orc/TargetProcess/CMakeLists.txt
+++ b/llvm/lib/ExecutionEngine/Orc/TargetProcess/CMakeLists.txt
@@ -14,6 +14,7 @@ endif()
add_llvm_component_library(LLVMOrcTargetProcess
ExecutorSharedMemoryMapperService.cpp
+ DefaultHostBootstrapValues.cpp
JITLoaderGDB.cpp
JITLoaderPerf.cpp
JITLoaderVTune.cpp
diff --git a/llvm/lib/ExecutionEngine/Orc/TargetProcess/DefaultHostBootstrapValues.cpp b/llvm/lib/ExecutionEngine/Orc/TargetProcess/DefaultHostBootstrapValues.cpp
new file mode 100644
index 000000000000000..c95b7ac5159fe65
--- /dev/null
+++ b/llvm/lib/ExecutionEngine/Orc/TargetProcess/DefaultHostBootstrapValues.cpp
@@ -0,0 +1,36 @@
+//===----- DefaultHostBootstrapValues.cpp - Defaults for host process -----===//
+//
+// 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/TargetProcess/DefaultHostBootstrapValues.h"
+
+#include "llvm/ExecutionEngine/Orc/Shared/OrcRTBridge.h"
+#include "llvm/ExecutionEngine/Orc/TargetProcess/RegisterEHFrames.h"
+
+#ifdef __APPLE__
+#include <dlfcn.h>
+#endif // __APPLE__
+
+namespace llvm::orc {
+
+void addDefaultBootstrapValuesForHostProcess(
+ StringMap<std::vector<char>> &BootstrapMap,
+ StringMap<ExecutorAddr> &BootstrapSymbols) {
+
+ // FIXME: We probably shouldn't set these on Windows?
+ BootstrapSymbols[rt::RegisterEHFrameSectionWrapperName] =
+ ExecutorAddr::fromPtr(&llvm_orc_registerEHFrameSectionWrapper);
+ BootstrapSymbols[rt::DeregisterEHFrameSectionWrapperName] =
+ ExecutorAddr::fromPtr(&llvm_orc_deregisterEHFrameSectionWrapper);
+
+#ifdef __APPLE__
+ if (!dlsym(RTLD_DEFAULT, "__unw_add_find_dynamic_unwind_sections"))
+ BootstrapMap["darwin-use-ehframes-only"].push_back(1);
+#endif // __APPLE__
+}
+
+} // namespace llvm::orc
diff --git a/llvm/lib/ExecutionEngine/Orc/TargetProcess/OrcRTBootstrap.cpp b/llvm/lib/ExecutionEngine/Orc/TargetProcess/OrcRTBootstrap.cpp
index d88fbbfc863850b..c4f201b353d2791 100644
--- a/llvm/lib/ExecutionEngine/Orc/TargetProcess/OrcRTBootstrap.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/TargetProcess/OrcRTBootstrap.cpp
@@ -106,10 +106,6 @@ void addTo(StringMap<ExecutorAddr> &M) {
ExecutorAddr::fromPtr(&writeBuffersWrapper);
M[rt::MemoryWritePointersWrapperName] =
ExecutorAddr::fromPtr(&writePointersWrapper);
- M[rt::RegisterEHFrameSectionWrapperName] =
- ExecutorAddr::fromPtr(&llvm_orc_registerEHFrameSectionWrapper);
- M[rt::DeregisterEHFrameSectionWrapperName] =
- ExecutorAddr::fromPtr(&llvm_orc_deregisterEHFrameSectionWrapper);
M[rt::RunAsMainWrapperName] = ExecutorAddr::fromPtr(&runAsMainWrapper);
M[rt::RunAsVoidFunctionWrapperName] =
ExecutorAddr::fromPtr(&runAsVoidFunctionWrapper);
diff --git a/llvm/tools/llvm-jitlink/llvm-jitlink-executor/llvm-jitlink-executor.cpp b/llvm/tools/llvm-jitlink/llvm-jitlink-executor/llvm-jitlink-executor.cpp
index 86b89a38c176010..dbdec7732777448 100644
--- a/llvm/tools/llvm-jitlink/llvm-jitlink-executor/llvm-jitlink-executor.cpp
+++ b/llvm/tools/llvm-jitlink/llvm-jitlink-executor/llvm-jitlink-executor.cpp
@@ -12,6 +12,7 @@
#include "llvm/ADT/StringRef.h"
#include "llvm/Config/llvm-config.h" // for LLVM_ON_UNIX, LLVM_ENABLE_THREADS
+#include "llvm/ExecutionEngine/Orc/TargetProcess/DefaultHostBootstrapValues.h"
#include "llvm/ExecutionEngine/Orc/TargetProcess/ExecutorSharedMemoryMapperService.h"
#include "llvm/ExecutionEngine/Orc/TargetProcess/JITLoaderGDB.h"
#include "llvm/ExecutionEngine/Orc/TargetProcess/RegisterEHFrames.h"
@@ -187,6 +188,8 @@ int main(int argc, char *argv[]) {
std::make_unique<SimpleRemoteEPCServer::ThreadDispatcher>());
S.bootstrapSymbols() =
SimpleRemoteEPCServer::defaultBootstrapSymbols();
+ addDefaultBootstrapValuesForHostProcess(S.bootstrapMap(),
+ S.bootstrapSymbols());
S.services().push_back(
std::make_unique<rt_bootstrap::SimpleExecutorMemoryManager>());
S.services().push_back(
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