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     ++IP;
  29   } else {
  30     // Otherwise, move I before IP and return IP.
  31     I->moveBefore(&*IP);
  32   }
  33   return IP;
  34 }
  35
  36 /// Instrumentation passes often insert conditional checks into entry blocks.
  37 /// Call this function before splitting the entry block to move instructions
  38 /// that must remain in the entry block up before the split point. Static
  39 /// allocas and llvm.localescape calls, for example, must remain in the entry
  40 /// block.
  41 BasicBlock::iterator llvm::PrepareToSplitEntryBlock(BasicBlock &BB,
  42                                                     BasicBlock::iterator IP) {
  43   assert(&BB.getParent()->getEntryBlock() == &BB);
  44   for (auto I = IP, E = BB.end(); I != E; ++I) {
  45     bool KeepInEntry = false;
  46     if (auto *AI = dyn_cast<AllocaInst>(I)) {
  47       if (AI->isStaticAlloca())
  48         KeepInEntry = true;
  49     } else if (auto *II = dyn_cast<IntrinsicInst>(I)) {
  50       if (II->getIntrinsicID() == llvm::Intrinsic::localescape)
  51         KeepInEntry = true;
  52     }
  53     if (KeepInEntry)
  54       IP = moveBeforeInsertPoint(I, IP);
  55   }
  56   return IP;
  57 }
  58
  59 // Create a constant for Str so that we can pass it to the run-time lib.
  60 GlobalVariable *llvm::createPrivateGlobalForString(Module &M, StringRef Str,
  61                                                    bool AllowMerging,
  62                                                    const char *NamePrefix) {
  63   Constant *StrConst = ConstantDataArray::getString(M.getContext(), Str);
  64   // We use private linkage for module-local strings. If they can be merged
  65   // with another one, we set the unnamed_addr attribute.
  66   GlobalVariable *GV =
  67       new GlobalVariable(M, StrConst->getType(), true,
  68                          GlobalValue::PrivateLinkage, StrConst, NamePrefix);
  69   if (AllowMerging)
  70     GV->setUnnamedAddr(GlobalValue::UnnamedAddr::Global);
  71   GV->setAlignment(Align::None()); // Strings may not be merged w/o setting
  72                                    // alignment explicitly.
  73   return GV;
  74 }
  75
  76 Comdat *llvm::GetOrCreateFunctionComdat(Function &F, Triple &T,
  77                                         const std::string &ModuleId) {
  78   if (auto Comdat = F.getComdat()) return Comdat;
  79   assert(F.hasName());
  80   Module *M = F.getParent();
  81   std::string Name = F.getName();
  82
  83   // Make a unique comdat name for internal linkage things on ELF. On COFF, the
  84   // name of the comdat group identifies the leader symbol of the comdat group.
  85   // The linkage of the leader symbol is considered during comdat resolution,
  86   // and internal symbols with the same name from different objects will not be
  87   // merged.
  88   if (T.isOSBinFormatELF() && F.hasLocalLinkage()) {
  89     if (ModuleId.empty())
  90       return nullptr;
  91     Name += ModuleId;
  92   }
  93
  94   // Make a new comdat for the function. Use the "no duplicates" selection kind
  95   // for non-weak symbols if the object file format supports it.
  96   Comdat *C = M->getOrInsertComdat(Name);
  97   if (T.isOSBinFormatCOFF() && !F.isWeakForLinker())
  98     C->setSelectionKind(Comdat::NoDuplicates);
  99   F.setComdat(C);
 100   return C;
 101 }
 102
 103 /// initializeInstrumentation - Initialize all passes in the TransformUtils
 104 /// library.
 105 void llvm::initializeInstrumentation(PassRegistry &Registry) {
 106   initializeAddressSanitizerLegacyPassPass(Registry);
 107   initializeModuleAddressSanitizerLegacyPassPass(Registry);
 108   initializeBoundsCheckingLegacyPassPass(Registry);
 109   initializeControlHeightReductionLegacyPassPass(Registry);
 110   initializeGCOVProfilerLegacyPassPass(Registry);
 111   initializePGOInstrumentationGenLegacyPassPass(Registry);
 112   initializePGOInstrumentationUseLegacyPassPass(Registry);
 113   initializePGOIndirectCallPromotionLegacyPassPass(Registry);
 114   initializePGOMemOPSizeOptLegacyPassPass(Registry);
 115   initializeInstrOrderFileLegacyPassPass(Registry);
 116   initializeInstrProfilingLegacyPassPass(Registry);
 117   initializeMemorySanitizerLegacyPassPass(Registry);
 118   initializeHWAddressSanitizerLegacyPassPass(Registry);
 119   initializeThreadSanitizerLegacyPassPass(Registry);
 120   initializeModuleSanitizerCoverageLegacyPassPass(Registry);
 121   initializeDataFlowSanitizerPass(Registry);
 122 }
 123
 124 /// LLVMInitializeInstrumentation - C binding for
 125 /// initializeInstrumentation.
 126 void LLVMInitializeInstrumentation(LLVMPassRegistryRef R) {
 127   initializeInstrumentation(*unwrap(R));
 128 }