diff options
| -rw-r--r-- | lib/ExecutionEngine/JIT/JITEmitter.cpp | 119 | ||||
| -rw-r--r-- | unittests/ExecutionEngine/JIT/JITTest.cpp | 23 |
2 files changed, 27 insertions, 115 deletions
diff --git a/lib/ExecutionEngine/JIT/JITEmitter.cpp b/lib/ExecutionEngine/JIT/JITEmitter.cpp index 0323a83c42..783ebb4deb 100644 --- a/lib/ExecutionEngine/JIT/JITEmitter.cpp +++ b/lib/ExecutionEngine/JIT/JITEmitter.cpp @@ -226,8 +226,6 @@ namespace { void getRelocatableGVs(SmallVectorImpl<GlobalValue*> &GVs, SmallVectorImpl<void*> &Ptrs); - GlobalValue *invalidateStub(void *Stub); - /// getGOTIndexForAddress - Return a new or existing index in the GOT for /// an address. This function only manages slots, it does not manage the /// contents of the slots or the memory associated with the GOT. @@ -371,16 +369,6 @@ namespace { ValueMap<const Function *, EmittedCode, EmittedFunctionConfig> EmittedFunctions; - // CurFnStubUses - For a given Function, a vector of stubs that it - // references. This facilitates the JIT detecting that a stub is no - // longer used, so that it may be deallocated. - DenseMap<AssertingVH<const Function>, SmallVector<void*, 1> > CurFnStubUses; - - // StubFnRefs - For a given pointer to a stub, a set of Functions which - // reference the stub. When the count of a stub's references drops to zero, - // the stub is unused. - DenseMap<void *, SmallPtrSet<const Function*, 1> > StubFnRefs; - DILocation PrevDLT; /// Instance of the JIT @@ -469,11 +457,6 @@ namespace { /// function body. void deallocateMemForFunction(const Function *F); - /// AddStubToCurrentFunction - Mark the current function being JIT'd as - /// using the stub at the specified address. Allows - /// deallocateMemForFunction to also remove stubs no longer referenced. - void AddStubToCurrentFunction(void *Stub); - virtual void processDebugLoc(DebugLoc DL, bool BeforePrintingInsn); virtual void emitLabel(uint64_t LabelID) { @@ -725,42 +708,6 @@ void JITResolver::getRelocatableGVs(SmallVectorImpl<GlobalValue*> &GVs, } } -GlobalValue *JITResolver::invalidateStub(void *Stub) { - MutexGuard locked(TheJIT->lock); - - // Remove the stub from the StubToResolverMap. - StubToResolverMap->UnregisterStubResolver(Stub); - - GlobalToIndirectSymMapTy &GM = state.getGlobalToIndirectSymMap(locked); - - // Look up the cheap way first, to see if it's a function stub we are - // invalidating. If so, remove it from both the forward and reverse maps. - if (Function *F = state.EraseStub(locked, Stub)) { - return F; - } - - // Otherwise, it might be an indirect symbol stub. Find it and remove it. - for (GlobalToIndirectSymMapTy::iterator i = GM.begin(), e = GM.end(); - i != e; ++i) { - if (i->second != Stub) - continue; - GlobalValue *GV = i->first; - GM.erase(i); - return GV; - } - - // Lastly, check to see if it's in the ExternalFnToStubMap. - for (std::map<void *, void *>::iterator i = ExternalFnToStubMap.begin(), - e = ExternalFnToStubMap.end(); i != e; ++i) { - if (i->second != Stub) - continue; - ExternalFnToStubMap.erase(i); - break; - } - - return 0; -} - /// JITCompilerFn - This function is called when a lazy compilation stub has /// been entered. It looks up which function this stub corresponds to, compiles /// it if necessary, then returns the resultant function pointer. @@ -846,7 +793,6 @@ void *JITEmitter::getPointerToGlobal(GlobalValue *V, void *Reference, // that we're returning the same address for the function as any previous // call. TODO: Yes, this is wrong. The lazy stub isn't guaranteed to be // close enough to call. - AddStubToCurrentFunction(FnStub); return FnStub; } @@ -863,18 +809,10 @@ void *JITEmitter::getPointerToGlobal(GlobalValue *V, void *Reference, return TheJIT->getPointerToFunction(F); } - // Otherwise, we may need a to emit a stub, and, conservatively, we - // always do so. - void *StubAddr = Resolver.getLazyFunctionStub(F); - - // Add the stub to the current function's list of referenced stubs, so we can - // deallocate them if the current function is ever freed. It's possible to - // return null from getLazyFunctionStub in the case of a weak extern that - // fails to resolve. - if (StubAddr) - AddStubToCurrentFunction(StubAddr); - - return StubAddr; + // Otherwise, we may need a to emit a stub, and, conservatively, we always do + // so. Note that it's possible to return null from getLazyFunctionStub in the + // case of a weak extern that fails to resolve. + return Resolver.getLazyFunctionStub(F); } void *JITEmitter::getPointerToGVIndirectSym(GlobalValue *V, void *Reference) { @@ -882,24 +820,9 @@ void *JITEmitter::getPointerToGVIndirectSym(GlobalValue *V, void *Reference) { // resolved address. void *GVAddress = getPointerToGlobal(V, Reference, false); void *StubAddr = Resolver.getGlobalValueIndirectSym(V, GVAddress); - - // Add the stub to the current function's list of referenced stubs, so we can - // deallocate them if the current function is ever freed. - AddStubToCurrentFunction(StubAddr); - return StubAddr; } -void JITEmitter::AddStubToCurrentFunction(void *StubAddr) { - assert(CurFn && "Stub added to current function, but current function is 0!"); - - SmallVectorImpl<void*> &StubsUsed = CurFnStubUses[CurFn]; - StubsUsed.push_back(StubAddr); - - SmallPtrSet<const Function *, 1> &FnRefs = StubFnRefs[StubAddr]; - FnRefs.insert(CurFn); -} - void JITEmitter::processDebugLoc(DebugLoc DL, bool BeforePrintingInsn) { if (!DL.isUnknown()) { DILocation CurDLT = EmissionDetails.MF->getDILocation(DL); @@ -1407,40 +1330,6 @@ void JITEmitter::deallocateMemForFunction(const Function *F) { if (JITEmitDebugInfo) { DR->UnregisterFunction(F); } - - // If the function did not reference any stubs, return. - if (CurFnStubUses.find(F) == CurFnStubUses.end()) - return; - - // For each referenced stub, erase the reference to this function, and then - // erase the list of referenced stubs. - SmallVectorImpl<void *> &StubList = CurFnStubUses[F]; - for (unsigned i = 0, e = StubList.size(); i != e; ++i) { - void *Stub = StubList[i]; - - // If we already invalidated this stub for this function, continue. - if (StubFnRefs.count(Stub) == 0) - continue; - - SmallPtrSet<const Function *, 1> &FnRefs = StubFnRefs[Stub]; - FnRefs.erase(F); - - // If this function was the last reference to the stub, invalidate the stub - // in the JITResolver. Were there a memory manager deallocateStub routine, - // we could call that at this point too. - if (FnRefs.empty()) { - DEBUG(dbgs() << "\nJIT: Invalidated Stub at [" << Stub << "]\n"); - StubFnRefs.erase(Stub); - - // Invalidate the stub. If it is a GV stub, update the JIT's global - // mapping for that GV to zero. - GlobalValue *GV = Resolver.invalidateStub(Stub); - if (GV) { - TheJIT->updateGlobalMapping(GV, 0); - } - } - } - CurFnStubUses.erase(F); } diff --git a/unittests/ExecutionEngine/JIT/JITTest.cpp b/unittests/ExecutionEngine/JIT/JITTest.cpp index 168bb3cb98..b85f724353 100644 --- a/unittests/ExecutionEngine/JIT/JITTest.cpp +++ b/unittests/ExecutionEngine/JIT/JITTest.cpp @@ -655,6 +655,29 @@ TEST_F(JITTest, NeedsExactSizeWithManyGlobals) { EXPECT_EQ(42, *********test()); } +TEST_F(JITTest, EscapedLazyStubStillCallable) { + TheJIT->DisableLazyCompilation(false); + LoadAssembly("define internal i32 @stubbed() { " + " ret i32 42 " + "} " + " " + "define i32()* @get_stub() { " + " ret i32()* @stubbed " + "} "); + typedef int32_t(*StubTy)(); + + // Call get_stub() to get the address of @stubbed without actually JITting it. + Function *get_stubIR = M->getFunction("get_stub"); + StubTy (*get_stub)() = reinterpret_cast<StubTy(*)()>( + (intptr_t)TheJIT->getPointerToFunction(get_stubIR)); + StubTy stubbed = get_stub(); + // Now get_stubIR is the only reference to stubbed's stub. + get_stubIR->eraseFromParent(); + // Now there are no references inside the JIT, but we've got a pointer outside + // it. The stub should be callable and return the right value. + EXPECT_EQ(42, stubbed()); +} + // Converts the LLVM assembly to bitcode and returns it in a std::string. An // empty string indicates an error. std::string AssembleToBitcode(LLVMContext &Context, const char *Assembly) { |