1 //===-- Instrumentation.cpp - TransformUtils Infrastructure ---------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file defines the common initialization infrastructure for the
11 // Instrumentation library.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "llvm/Transforms/Instrumentation.h"
16 #include "llvm-c/Initialization.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,
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   if (F.hasLocalLinkage()) {
80     if (ModuleId.empty())
81       return nullptr;
82     Name += ModuleId;
83   }
84   F.setComdat(M->getOrInsertComdat(Name));
85   return F.getComdat();
86 }
87 
88 /// initializeInstrumentation - Initialize all passes in the TransformUtils
89 /// library.
90 void llvm::initializeInstrumentation(PassRegistry &Registry) {
91   initializeAddressSanitizerLegacyPassPass(Registry);
92   initializeAddressSanitizerModuleLegacyPassPass(Registry);
93   initializeBoundsCheckingLegacyPassPass(Registry);
94   initializeControlHeightReductionLegacyPassPass(Registry);
95   initializeGCOVProfilerLegacyPassPass(Registry);
96   initializePGOInstrumentationGenLegacyPassPass(Registry);
97   initializePGOInstrumentationUseLegacyPassPass(Registry);
98   initializePGOIndirectCallPromotionLegacyPassPass(Registry);
99   initializePGOMemOPSizeOptLegacyPassPass(Registry);
100   initializeInstrProfilingLegacyPassPass(Registry);
101   initializeMemorySanitizerPass(Registry);
102   initializeHWAddressSanitizerPass(Registry);
103   initializeThreadSanitizerPass(Registry);
104   initializeSanitizerCoverageModulePass(Registry);
105   initializeDataFlowSanitizerPass(Registry);
106   initializeEfficiencySanitizerPass(Registry);
107 }
108 
109 /// LLVMInitializeInstrumentation - C binding for
110 /// initializeInstrumentation.
111 void LLVMInitializeInstrumentation(LLVMPassRegistryRef R) {
112   initializeInstrumentation(*unwrap(R));
113 }
114