Instrumentation.cpp revision 360784 
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
22using namespace llvm;
23
24/// Moves I before IP. Returns new insert point.
25static 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.
41BasicBlock::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.
60GlobalVariable *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
76Comdat *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.
105void 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.
126void LLVMInitializeInstrumentation(LLVMPassRegistryRef R) {
127  initializeInstrumentation(*unwrap(R));
128}
129