1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
|
//===- EntryExitInstrumenter.cpp - Function Entry/Exit Instrumentation ----===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "llvm/Transforms/Utils/EntryExitInstrumenter.h"
#include "llvm/Analysis/GlobalsModRef.h"
#include "llvm/IR/DebugInfoMetadata.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Type.h"
#include "llvm/InitializePasses.h"
#include "llvm/Pass.h"
#include "llvm/Transforms/Utils.h"
using namespace llvm;
static void insertCall(Function &CurFn, StringRef Func,
Instruction *InsertionPt, DebugLoc DL) {
Module &M = *InsertionPt->getParent()->getParent()->getParent();
LLVMContext &C = InsertionPt->getParent()->getContext();
if (Func == "mcount" ||
Func == ".mcount" ||
Func == "llvm.arm.gnu.eabi.mcount" ||
Func == "\01_mcount" ||
Func == "\01mcount" ||
Func == "__mcount" ||
Func == "_mcount" ||
Func == "__cyg_profile_func_enter_bare") {
FunctionCallee Fn = M.getOrInsertFunction(Func, Type::getVoidTy(C));
CallInst *Call = CallInst::Create(Fn, "", InsertionPt);
Call->setDebugLoc(DL);
return;
}
if (Func == "__cyg_profile_func_enter" || Func == "__cyg_profile_func_exit") {
Type *ArgTypes[] = {Type::getInt8PtrTy(C), Type::getInt8PtrTy(C)};
FunctionCallee Fn = M.getOrInsertFunction(
Func, FunctionType::get(Type::getVoidTy(C), ArgTypes, false));
Instruction *RetAddr = CallInst::Create(
Intrinsic::getDeclaration(&M, Intrinsic::returnaddress),
ArrayRef<Value *>(ConstantInt::get(Type::getInt32Ty(C), 0)), "",
InsertionPt);
RetAddr->setDebugLoc(DL);
Value *Args[] = {ConstantExpr::getBitCast(&CurFn, Type::getInt8PtrTy(C)),
RetAddr};
CallInst *Call =
CallInst::Create(Fn, ArrayRef<Value *>(Args), "", InsertionPt);
Call->setDebugLoc(DL);
return;
}
// We only know how to call a fixed set of instrumentation functions, because
// they all expect different arguments, etc.
report_fatal_error(Twine("Unknown instrumentation function: '") + Func + "'");
}
static bool runOnFunction(Function &F, bool PostInlining) {
StringRef EntryAttr = PostInlining ? "instrument-function-entry-inlined"
: "instrument-function-entry";
StringRef ExitAttr = PostInlining ? "instrument-function-exit-inlined"
: "instrument-function-exit";
StringRef EntryFunc = F.getFnAttribute(EntryAttr).getValueAsString();
StringRef ExitFunc = F.getFnAttribute(ExitAttr).getValueAsString();
bool Changed = false;
// If the attribute is specified, insert instrumentation and then "consume"
// the attribute so that it's not inserted again if the pass should happen to
// run later for some reason.
if (!EntryFunc.empty()) {
DebugLoc DL;
if (auto SP = F.getSubprogram())
DL = DILocation::get(SP->getContext(), SP->getScopeLine(), 0, SP);
insertCall(F, EntryFunc, &*F.begin()->getFirstInsertionPt(), DL);
Changed = true;
F.removeAttribute(AttributeList::FunctionIndex, EntryAttr);
}
if (!ExitFunc.empty()) {
for (BasicBlock &BB : F) {
Instruction *T = BB.getTerminator();
if (!isa<ReturnInst>(T))
continue;
// If T is preceded by a musttail call, that's the real terminator.
if (CallInst *CI = BB.getTerminatingMustTailCall())
T = CI;
DebugLoc DL;
if (DebugLoc TerminatorDL = T->getDebugLoc())
DL = TerminatorDL;
else if (auto SP = F.getSubprogram())
DL = DILocation::get(SP->getContext(), 0, 0, SP);
insertCall(F, ExitFunc, T, DL);
Changed = true;
}
F.removeAttribute(AttributeList::FunctionIndex, ExitAttr);
}
return Changed;
}
namespace {
struct EntryExitInstrumenter : public FunctionPass {
static char ID;
EntryExitInstrumenter() : FunctionPass(ID) {
initializeEntryExitInstrumenterPass(*PassRegistry::getPassRegistry());
}
void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.addPreserved<GlobalsAAWrapperPass>();
}
bool runOnFunction(Function &F) override { return ::runOnFunction(F, false); }
};
char EntryExitInstrumenter::ID = 0;
struct PostInlineEntryExitInstrumenter : public FunctionPass {
static char ID;
PostInlineEntryExitInstrumenter() : FunctionPass(ID) {
initializePostInlineEntryExitInstrumenterPass(
*PassRegistry::getPassRegistry());
}
void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.addPreserved<GlobalsAAWrapperPass>();
}
bool runOnFunction(Function &F) override { return ::runOnFunction(F, true); }
};
char PostInlineEntryExitInstrumenter::ID = 0;
}
INITIALIZE_PASS(
EntryExitInstrumenter, "ee-instrument",
"Instrument function entry/exit with calls to e.g. mcount() (pre inlining)",
false, false)
INITIALIZE_PASS(PostInlineEntryExitInstrumenter, "post-inline-ee-instrument",
"Instrument function entry/exit with calls to e.g. mcount() "
"(post inlining)",
false, false)
FunctionPass *llvm::createEntryExitInstrumenterPass() {
return new EntryExitInstrumenter();
}
FunctionPass *llvm::createPostInlineEntryExitInstrumenterPass() {
return new PostInlineEntryExitInstrumenter();
}
PreservedAnalyses
llvm::EntryExitInstrumenterPass::run(Function &F, FunctionAnalysisManager &AM) {
runOnFunction(F, PostInlining);
PreservedAnalyses PA;
PA.preserveSet<CFGAnalyses>();
return PA;
}
|
