52cf07116b
Make core BOLT functionality more friendly to being used as a library instead of in our standalone driver llvm-bolt. To accomplish this, we augment BinaryContext with journaling streams that are to be used by most BOLT code whenever something needs to be logged to the screen. Users of the library can decide if logs should be printed to a file, no file or to the screen, as before. To illustrate this, this patch adds a new option `--log-file` that allows the user to redirect BOLT logging to a file on disk or completely hide it by using `--log-file=/dev/null`. Future BOLT code should now use `BinaryContext::outs()` for printing important messages instead of `llvm::outs()`. A new test log.test enforces this by verifying that no strings are print to screen once the `--log-file` option is used. In previous patches we also added a new BOLTError class to report common and fatal errors, so code shouldn't call exit(1) now. To easily handle problems as before (by quitting with exit(1)), callers can now use `BinaryContext::logBOLTErrorsAndQuitOnFatal(Error)` whenever code needs to deal with BOLT errors. To test this, we have fatal.s that checks we are correctly quitting and printing a fatal error to the screen. Because this is a significant change by itself, not all code was yet ported. Code from Profiler libs (DataAggregator and friends) still print errors directly to screen. Co-authored-by: Rafael Auler <rafaelauler@fb.com> Test Plan: NFC
105 lines
3.6 KiB
C++
105 lines
3.6 KiB
C++
//===- bolt/Passes/ValidateMemRefs.cpp ------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "bolt/Passes/ValidateMemRefs.h"
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#include "bolt/Core/ParallelUtilities.h"
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#define DEBUG_TYPE "bolt-memrefs"
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namespace opts {
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extern llvm::cl::opt<llvm::bolt::JumpTableSupportLevel> JumpTables;
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}
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namespace llvm::bolt {
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std::atomic<std::uint64_t> ValidateMemRefs::ReplacedReferences{0};
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bool ValidateMemRefs::checkAndFixJTReference(BinaryFunction &BF, MCInst &Inst,
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uint32_t OperandNum,
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const MCSymbol *Sym,
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uint64_t Offset) {
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BinaryContext &BC = BF.getBinaryContext();
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auto L = BC.scopeLock();
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BinaryData *BD = BC.getBinaryDataByName(Sym->getName());
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if (!BD)
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return false;
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const uint64_t TargetAddress = BD->getAddress() + Offset;
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JumpTable *JT = BC.getJumpTableContainingAddress(TargetAddress);
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if (!JT)
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return false;
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const bool IsLegitAccess = llvm::is_contained(JT->Parents, &BF);
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if (IsLegitAccess)
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return true;
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// Accessing a jump table in another function. This is not a
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// legitimate jump table access, we need to replace the reference to
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// the jump table label with a regular rodata reference. Get a
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// non-JT reference by fetching the symbol 1 byte before the JT
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// label.
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MCSymbol *NewSym = BC.getOrCreateGlobalSymbol(TargetAddress - 1, "DATAat");
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BC.MIB->setOperandToSymbolRef(Inst, OperandNum, NewSym, 1, &*BC.Ctx, 0);
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LLVM_DEBUG(dbgs() << "BOLT-DEBUG: replaced reference @" << BF.getPrintName()
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<< " from " << BD->getName() << " to " << NewSym->getName()
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<< " + 1\n");
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++ReplacedReferences;
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return true;
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}
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void ValidateMemRefs::runOnFunction(BinaryFunction &BF) {
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MCPlusBuilder *MIB = BF.getBinaryContext().MIB.get();
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for (BinaryBasicBlock &BB : BF) {
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for (MCInst &Inst : BB) {
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for (int I = 0, E = MCPlus::getNumPrimeOperands(Inst); I != E; ++I) {
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const MCOperand &Operand = Inst.getOperand(I);
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if (!Operand.isExpr())
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continue;
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const auto [Sym, Offset] = MIB->getTargetSymbolInfo(Operand.getExpr());
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if (!Sym)
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continue;
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checkAndFixJTReference(BF, Inst, I, Sym, Offset);
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}
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}
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}
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}
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Error ValidateMemRefs::runOnFunctions(BinaryContext &BC) {
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if (!BC.isX86())
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return Error::success();
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// Skip validation if not moving JT
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if (opts::JumpTables == JTS_NONE || opts::JumpTables == JTS_BASIC)
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return Error::success();
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ParallelUtilities::WorkFuncWithAllocTy ProcessFunction =
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[&](BinaryFunction &BF, MCPlusBuilder::AllocatorIdTy AllocId) {
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runOnFunction(BF);
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};
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ParallelUtilities::PredicateTy SkipPredicate = [&](const BinaryFunction &BF) {
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return !BF.hasCFG();
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};
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LLVM_DEBUG(dbgs() << "BOLT-DEBUG: starting memrefs validation pass\n");
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ParallelUtilities::runOnEachFunctionWithUniqueAllocId(
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BC, ParallelUtilities::SchedulingPolicy::SP_INST_LINEAR, ProcessFunction,
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SkipPredicate, "validate-mem-refs", /*ForceSequential=*/true);
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LLVM_DEBUG(dbgs() << "BOLT-DEBUG: memrefs validation is concluded\n");
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if (!ReplacedReferences)
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return Error::success();
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BC.outs() << "BOLT-INFO: validate-mem-refs updated " << ReplacedReferences
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<< " object references\n";
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return Error::success();
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}
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} // namespace llvm::bolt
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