From 0071eaaf0892d7ef733578312abefdcf84311071 Mon Sep 17 00:00:00 2001 From: Lang Hames Date: Wed, 1 Apr 2020 15:28:28 -0700 Subject: [PATCH] [ORC] Export __cxa_atexit from the main JITDylib in LLJIT. Failure to export __cxa_atexit can lead to an attempt to import a definition from the process itself (if __cxa_atexit is referenced from another JITDylib), but the process definition will clash with the existing non-exported definition to produce an unexpected DuplicateDefinitionError. This patch fixes the immediate issue by exporting __cxa_atexit. It also fixes a bug where atexit functions in other JITDylibs were not being run by adding a copy of run_atexits_helper to every JITDylib. A follow up patch will deal with the bug where definition generators are called despite a non-exported definition being present. --- llvm/lib/ExecutionEngine/Orc/LLJIT.cpp | 66 +++++++++++++++------- .../OrcLazy/global-ctors-and-dtors.ll | 15 ++--- 2 files changed, 53 insertions(+), 28 deletions(-) diff --git a/llvm/lib/ExecutionEngine/Orc/LLJIT.cpp b/llvm/lib/ExecutionEngine/Orc/LLJIT.cpp index 3be1381..9a868a6 100644 --- a/llvm/lib/ExecutionEngine/Orc/LLJIT.cpp +++ b/llvm/lib/ExecutionEngine/Orc/LLJIT.cpp @@ -29,14 +29,6 @@ using namespace llvm::orc; namespace { -/// Add a reference to the __dso_handle global to the given module. -/// Returns a reference to the __dso_handle IR decl. -GlobalVariable *addDSOHandleDecl(Module &M) { - auto DSOHandleTy = StructType::create(M.getContext(), "lljit.dso_handle"); - return new GlobalVariable(M, DSOHandleTy, true, GlobalValue::ExternalLinkage, - nullptr, "__dso_handle"); -} - /// Adds helper function decls and wrapper functions that call the helper with /// some additional prefix arguments. /// @@ -143,11 +135,10 @@ public: SymbolMap StdInterposes; StdInterposes[Mangle("__lljit.platform_support_instance")] = - JITEvaluatedSymbol(pointerToJITTargetAddress(this), JITSymbolFlags()); + JITEvaluatedSymbol(pointerToJITTargetAddress(this), + JITSymbolFlags::Exported); StdInterposes[Mangle("__lljit.cxa_atexit_helper")] = JITEvaluatedSymbol( pointerToJITTargetAddress(registerAtExitHelper), JITSymbolFlags()); - StdInterposes[Mangle("__lljit.run_atexits_helper")] = JITEvaluatedSymbol( - pointerToJITTargetAddress(runAtExitsHelper), JITSymbolFlags()); cantFail( J.getMainJITDylib().define(absoluteSymbols(std::move(StdInterposes)))); @@ -159,6 +150,14 @@ public: /// Adds a module that defines the __dso_handle global. Error setupJITDylib(JITDylib &JD) { + + // Add per-jitdylib standard interposes. + MangleAndInterner Mangle(getExecutionSession(), J.getDataLayout()); + SymbolMap PerJDInterposes; + PerJDInterposes[Mangle("__lljit.run_atexits_helper")] = JITEvaluatedSymbol( + pointerToJITTargetAddress(runAtExitsHelper), JITSymbolFlags()); + cantFail(JD.define(absoluteSymbols(std::move(PerJDInterposes)))); + auto Ctx = std::make_unique(); auto M = std::make_unique("__standard_lib", *Ctx); M->setDataLayout(J.getDataLayout()); @@ -168,9 +167,23 @@ public: *M, Int64Ty, true, GlobalValue::ExternalLinkage, ConstantInt::get(Int64Ty, reinterpret_cast(&JD)), "__dso_handle"); - DSOHandle->setVisibility(GlobalValue::HiddenVisibility); + DSOHandle->setVisibility(GlobalValue::DefaultVisibility); DSOHandle->setInitializer( ConstantInt::get(Int64Ty, pointerToJITTargetAddress(&JD))); + + auto *GenericIRPlatformSupportTy = + StructType::create(*Ctx, "lljit.GenericLLJITIRPlatformSupport"); + + auto *PlatformInstanceDecl = new GlobalVariable( + *M, GenericIRPlatformSupportTy, true, GlobalValue::ExternalLinkage, + nullptr, "__lljit.platform_support_instance"); + + auto *VoidTy = Type::getVoidTy(*Ctx); + addHelperAndWrapper( + *M, "__lljit_run_atexits", FunctionType::get(VoidTy, {}, false), + GlobalValue::HiddenVisibility, "__lljit.run_atexits_helper", + {PlatformInstanceDecl, DSOHandle}); + return J.addIRModule(JD, ThreadSafeModule(std::move(M), std::move(Ctx))); } @@ -316,6 +329,16 @@ private: } }); + LLVM_DEBUG({ + dbgs() << "JITDylib deinit order is [ "; + for (auto *JD : DFSLinkOrder) + dbgs() << "\"" << JD->getName() << "\" "; + dbgs() << "]\n"; + dbgs() << "Looking up deinit functions:\n"; + for (auto &KV : LookupSymbols) + dbgs() << " \"" << KV.first->getName() << "\": " << KV.second << "\n"; + }); + auto LookupResult = Platform::lookupInitSymbols(ES, LookupSymbols); if (!LookupResult) @@ -387,11 +410,19 @@ private: static void registerAtExitHelper(void *Self, void (*F)(void *), void *Ctx, void *DSOHandle) { + LLVM_DEBUG({ + dbgs() << "Registering atexit function " << (void *)F << " for JD " + << (*static_cast(DSOHandle))->getName() << "\n"; + }); static_cast(Self)->AtExitMgr.registerAtExit( F, Ctx, DSOHandle); } static void runAtExitsHelper(void *Self, void *DSOHandle) { + LLVM_DEBUG({ + dbgs() << "Running atexit functions for JD " + << (*static_cast(DSOHandle))->getName() << "\n"; + }); static_cast(Self)->AtExitMgr.runAtExits( DSOHandle); } @@ -410,8 +441,6 @@ private: *M, GenericIRPlatformSupportTy, true, GlobalValue::ExternalLinkage, nullptr, "__lljit.platform_support_instance"); - auto *DSOHandleDecl = addDSOHandleDecl(*M); - auto *Int8Ty = Type::getInt8Ty(*Ctx); auto *IntTy = Type::getIntNTy(*Ctx, sizeof(int) * CHAR_BIT); auto *VoidTy = Type::getVoidTy(*Ctx); @@ -423,14 +452,9 @@ private: *M, "__cxa_atexit", FunctionType::get(IntTy, {AtExitCallbackPtrTy, BytePtrTy, BytePtrTy}, false), - GlobalValue::HiddenVisibility, "__lljit.cxa_atexit_helper", + GlobalValue::DefaultVisibility, "__lljit.cxa_atexit_helper", {PlatformInstanceDecl}); - addHelperAndWrapper( - *M, "__lljit_run_atexits", FunctionType::get(VoidTy, {}, false), - GlobalValue::HiddenVisibility, "__lljit.run_atexits_helper", - {PlatformInstanceDecl, DSOHandleDecl}); - return ThreadSafeModule(std::move(M), std::move(Ctx)); } @@ -676,7 +700,7 @@ private: auto *DSOHandle = new GlobalVariable(M, Int64Ty, true, GlobalValue::ExternalLinkage, ConstantInt::get(Int64Ty, 0), "__dso_handle"); - DSOHandle->setVisibility(GlobalValue::HiddenVisibility); + DSOHandle->setVisibility(GlobalValue::DefaultVisibility); return cantFail(J.getIRCompileLayer().getCompiler()(M)); } diff --git a/llvm/test/ExecutionEngine/OrcLazy/global-ctors-and-dtors.ll b/llvm/test/ExecutionEngine/OrcLazy/global-ctors-and-dtors.ll index 00b54fb..67d392e 100644 --- a/llvm/test/ExecutionEngine/OrcLazy/global-ctors-and-dtors.ll +++ b/llvm/test/ExecutionEngine/OrcLazy/global-ctors-and-dtors.ll @@ -1,6 +1,12 @@ -; RUN: lli -jit-kind=orc-lazy -orc-lazy-debug=funcs-to-stdout %s | FileCheck %s +; Test that global constructors and destructors are run: ; -; Test that global constructors and destructors are run. +; RUN: lli -jit-kind=orc-lazy -orc-lazy-debug=funcs-to-stdout -extra-module %s \ +; RUN: %S/Inputs/noop-main.ll | FileCheck %s +; +; Test that this is true for global constructors and destructors in other +; JITDylibs. +; RUN: lli -jit-kind=orc-lazy -orc-lazy-debug=funcs-to-stdout \ +; RUN: -jd extra -extra-module %s -jd main %S/Inputs/noop-main.ll | FileCheck %s ; ; CHECK: Hello ; CHECK: [ {{.*}}main{{.*}} ] @@ -22,11 +28,6 @@ entry: declare i32 @__cxa_atexit(void (i8*)*, i8*, i8*) -define i32 @main(i32 %argc, i8** nocapture readnone %argv) { -entry: - ret i32 0 -} - define internal void @_GLOBAL__sub_I_hello.cpp() { entry: %puts.i.i.i = tail call i32 @puts(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @str, i64 0, i64 0)) -- 2.7.4