lib/Transforms/Instrumentation/Instrumentation.cpp

   1 //===-- Instrumentation.cpp - TransformUtils Infrastructure ---------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file defines the common initialization infrastructure for the
  10 // Instrumentation library.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/Transforms/Instrumentation.h"
  15 #include "llvm-c/Initialization.h"
  16 #include "llvm/ADT/Triple.h"
  17 #include "llvm/IR/IntrinsicInst.h"
  18 #include "llvm/IR/Module.h"
  19 #include "llvm/InitializePasses.h"
  20 #include "llvm/PassRegistry.h"
  21
  22 using namespace llvm;
  23
  24 /// Moves I before IP. Returns new insert point.
  25 static BasicBlock::iterator moveBeforeInsertPoint(BasicBlock::iterator I, BasicBlock::iterator IP) {
  26   // If I is IP, move the insert point down.
  27   if (I == IP)
  28     return ++IP;
  29   // Otherwise, move I before IP and return IP.
  30   I->moveBefore(&*IP);
  31   return IP;
  32 }
  33
  34 /// Instrumentation passes often insert conditional checks into entry blocks.
  35 /// Call this function before splitting the entry block to move instructions
  36 /// that must remain in the entry block up before the split point. Static
  37 /// allocas and llvm.localescape calls, for example, must remain in the entry
  38 /// block.
  39 BasicBlock::iterator llvm::PrepareToSplitEntryBlock(BasicBlock &BB,
  40                                                     BasicBlock::iterator IP) {
  41   assert(&BB.getParent()->getEntryBlock() == &BB);
  42   for (auto I = IP, E = BB.end(); I != E; ++I) {
  43     bool KeepInEntry = false;
  44     if (auto *AI = dyn_cast<AllocaInst>(I)) {
  45       if (AI->isStaticAlloca())
  46         KeepInEntry = true;
  47     } else if (auto *II = dyn_cast<IntrinsicInst>(I)) {
  48       if (II->getIntrinsicID() == llvm::Intrinsic::localescape)
  49         KeepInEntry = true;
  50     }
  51     if (KeepInEntry)
  52       IP = moveBeforeInsertPoint(I, IP);
  53   }
  54   return IP;
  55 }
  56
  57 // Create a constant for Str so that we can pass it to the run-time lib.
  58 GlobalVariable *llvm::createPrivateGlobalForString(Module &M, StringRef Str,
  59                                                    bool AllowMerging,
  60                                                    const char *NamePrefix) {
  61   Constant *StrConst = ConstantDataArray::getString(M.getContext(), Str);
  62   // We use private linkage for module-local strings. If they can be merged
  63   // with another one, we set the unnamed_addr attribute.
  64   GlobalVariable *GV =
  65       new GlobalVariable(M, StrConst->getType(), true,
  66                          GlobalValue::PrivateLinkage, StrConst, NamePrefix);
  67   if (AllowMerging)
  68     GV->setUnnamedAddr(GlobalValue::UnnamedAddr::Global);
  69   GV->setAlignment(1);  // Strings may not be merged w/o setting align 1.
  70   return GV;
  71 }
  72
  73 Comdat *llvm::GetOrCreateFunctionComdat(Function &F, Triple &T,
  74                                         const std::string &ModuleId) {
  75   if (auto Comdat = F.getComdat()) return Comdat;
  76   assert(F.hasName());
  77   Module *M = F.getParent();
  78   std::string Name = F.getName();
  79
  80   // Make a unique comdat name for internal linkage things on ELF. On COFF, the
  81   // name of the comdat group identifies the leader symbol of the comdat group.
  82   // The linkage of the leader symbol is considered during comdat resolution,
  83   // and internal symbols with the same name from different objects will not be
  84   // merged.
  85   if (T.isOSBinFormatELF() && F.hasLocalLinkage()) {
  86     if (ModuleId.empty())
  87       return nullptr;
  88     Name += ModuleId;
  89   }
  90
  91   // Make a new comdat for the function. Use the "no duplicates" selection kind
  92   // for non-weak symbols if the object file format supports it.
  93   Comdat *C = M->getOrInsertComdat(Name);
  94   if (T.isOSBinFormatCOFF() && !F.isWeakForLinker())
  95     C->setSelectionKind(Comdat::NoDuplicates);
  96   F.setComdat(C);
  97   return C;
  98 }
  99
 100 /// initializeInstrumentation - Initialize all passes in the TransformUtils
 101 /// library.
 102 void llvm::initializeInstrumentation(PassRegistry &Registry) {
 103   initializeAddressSanitizerLegacyPassPass(Registry);
 104   initializeModuleAddressSanitizerLegacyPassPass(Registry);
 105   initializeBoundsCheckingLegacyPassPass(Registry);
 106   initializeControlHeightReductionLegacyPassPass(Registry);
 107   initializeGCOVProfilerLegacyPassPass(Registry);
 108   initializePGOInstrumentationGenLegacyPassPass(Registry);
 109   initializePGOInstrumentationUseLegacyPassPass(Registry);
 110   initializePGOIndirectCallPromotionLegacyPassPass(Registry);
 111   initializePGOMemOPSizeOptLegacyPassPass(Registry);
 112   initializeInstrProfilingLegacyPassPass(Registry);
 113   initializeMemorySanitizerLegacyPassPass(Registry);
 114   initializeHWAddressSanitizerPass(Registry);
 115   initializeThreadSanitizerLegacyPassPass(Registry);
 116   initializeSanitizerCoverageModulePass(Registry);
 117   initializeDataFlowSanitizerPass(Registry);
 118   initializeEfficiencySanitizerPass(Registry);
 119 }
 120
 121 /// LLVMInitializeInstrumentation - C binding for
 122 /// initializeInstrumentation.
 123 void LLVMInitializeInstrumentation(LLVMPassRegistryRef R) {
 124   initializeInstrumentation(*unwrap(R));
 125 }