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
|
//===- AliasDebugger.cpp - Simple Alias Analysis Use Checker --------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This simple pass checks alias analysis users to ensure that if they
// create a new value, they do not query AA without informing it of the value.
// It acts as a shim over any other AA pass you want.
//
// Yes keeping track of every value in the program is expensive, but this is
// a debugging pass.
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/Passes.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Module.h"
#include "llvm/Pass.h"
#include <set>
using namespace llvm;
namespace {
class AliasDebugger : public ModulePass, public AliasAnalysis {
//What we do is simple. Keep track of every value the AA could
//know about, and verify that queries are one of those.
//A query to a value that didn't exist when the AA was created
//means someone forgot to update the AA when creating new values
std::set<const Value*> Vals;
public:
static char ID; // Class identification, replacement for typeinfo
AliasDebugger() : ModulePass(ID) {
initializeAliasDebuggerPass(*PassRegistry::getPassRegistry());
}
bool runOnModule(Module &M) override {
InitializeAliasAnalysis(this); // set up super class
for(Module::global_iterator I = M.global_begin(),
E = M.global_end(); I != E; ++I) {
Vals.insert(&*I);
for (User::const_op_iterator OI = I->op_begin(),
OE = I->op_end(); OI != OE; ++OI)
Vals.insert(*OI);
}
for(Module::iterator I = M.begin(),
E = M.end(); I != E; ++I){
Vals.insert(&*I);
if(!I->isDeclaration()) {
for (Function::arg_iterator AI = I->arg_begin(), AE = I->arg_end();
AI != AE; ++AI)
Vals.insert(&*AI);
for (Function::const_iterator FI = I->begin(), FE = I->end();
FI != FE; ++FI)
for (BasicBlock::const_iterator BI = FI->begin(), BE = FI->end();
BI != BE; ++BI) {
Vals.insert(&*BI);
for (User::const_op_iterator OI = BI->op_begin(),
OE = BI->op_end(); OI != OE; ++OI)
Vals.insert(*OI);
}
}
}
return false;
}
void getAnalysisUsage(AnalysisUsage &AU) const override {
AliasAnalysis::getAnalysisUsage(AU);
AU.setPreservesAll(); // Does not transform code
}
/// getAdjustedAnalysisPointer - This method is used when a pass implements
/// an analysis interface through multiple inheritance. If needed, it
/// should override this to adjust the this pointer as needed for the
/// specified pass info.
void *getAdjustedAnalysisPointer(AnalysisID PI) override {
if (PI == &AliasAnalysis::ID)
return (AliasAnalysis*)this;
return this;
}
//------------------------------------------------
// Implement the AliasAnalysis API
//
AliasResult alias(const Location &LocA, const Location &LocB) override {
assert(Vals.find(LocA.Ptr) != Vals.end() &&
"Never seen value in AA before");
assert(Vals.find(LocB.Ptr) != Vals.end() &&
"Never seen value in AA before");
return AliasAnalysis::alias(LocA, LocB);
}
ModRefResult getModRefInfo(ImmutableCallSite CS,
const Location &Loc) override {
assert(Vals.find(Loc.Ptr) != Vals.end() && "Never seen value in AA before");
return AliasAnalysis::getModRefInfo(CS, Loc);
}
ModRefResult getModRefInfo(ImmutableCallSite CS1,
ImmutableCallSite CS2) override {
return AliasAnalysis::getModRefInfo(CS1,CS2);
}
bool pointsToConstantMemory(const Location &Loc, bool OrLocal) override {
assert(Vals.find(Loc.Ptr) != Vals.end() && "Never seen value in AA before");
return AliasAnalysis::pointsToConstantMemory(Loc, OrLocal);
}
void deleteValue(Value *V) override {
assert(Vals.find(V) != Vals.end() && "Never seen value in AA before");
AliasAnalysis::deleteValue(V);
}
void copyValue(Value *From, Value *To) override {
Vals.insert(To);
AliasAnalysis::copyValue(From, To);
}
};
}
char AliasDebugger::ID = 0;
INITIALIZE_AG_PASS(AliasDebugger, AliasAnalysis, "debug-aa",
"AA use debugger", false, true, false)
Pass *llvm::createAliasDebugger() { return new AliasDebugger(); }
|
