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
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
|
//===-- Internalize.cpp - Mark functions internal -------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This pass loops over all of the functions in the input module, looking for a
// main function. If a main function is found, all other functions and all
// global variables with initializers are marked as internal.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "internalize"
#include "llvm/Analysis/CallGraph.h"
#include "llvm/Transforms/IPO.h"
#include "llvm/Pass.h"
#include "llvm/Module.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/ADT/Statistic.h"
#include <fstream>
#include <set>
using namespace llvm;
STATISTIC(NumAliases , "Number of aliases internalized");
STATISTIC(NumFunctions, "Number of functions internalized");
STATISTIC(NumGlobals , "Number of global vars internalized");
// APIFile - A file which contains a list of symbols that should not be marked
// external.
static cl::opt<std::string>
APIFile("internalize-public-api-file", cl::value_desc("filename"),
cl::desc("A file containing list of symbol names to preserve"));
// APIList - A list of symbols that should not be marked internal.
static cl::list<std::string>
APIList("internalize-public-api-list", cl::value_desc("list"),
cl::desc("A list of symbol names to preserve"),
cl::CommaSeparated);
namespace {
class InternalizePass : public ModulePass {
std::set<std::string> ExternalNames;
/// If no api symbols were specified and a main function is defined,
/// assume the main function is the only API
bool AllButMain;
public:
static char ID; // Pass identification, replacement for typeid
explicit InternalizePass(bool AllButMain = true);
explicit InternalizePass(const std::vector <const char *>& exportList);
void LoadFile(const char *Filename);
virtual bool runOnModule(Module &M);
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesCFG();
AU.addPreserved<CallGraph>();
}
};
} // end anonymous namespace
char InternalizePass::ID = 0;
INITIALIZE_PASS(InternalizePass, "internalize",
"Internalize Global Symbols", false, false);
InternalizePass::InternalizePass(bool AllButMain)
: ModulePass(ID), AllButMain(AllButMain){
if (!APIFile.empty()) // If a filename is specified, use it.
LoadFile(APIFile.c_str());
if (!APIList.empty()) // If a list is specified, use it as well.
ExternalNames.insert(APIList.begin(), APIList.end());
}
InternalizePass::InternalizePass(const std::vector<const char *>&exportList)
: ModulePass(ID), AllButMain(false){
for(std::vector<const char *>::const_iterator itr = exportList.begin();
itr != exportList.end(); itr++) {
ExternalNames.insert(*itr);
}
}
void InternalizePass::LoadFile(const char *Filename) {
// Load the APIFile...
std::ifstream In(Filename);
if (!In.good()) {
errs() << "WARNING: Internalize couldn't load file '" << Filename
<< "'! Continuing as if it's empty.\n";
return; // Just continue as if the file were empty
}
while (In) {
std::string Symbol;
In >> Symbol;
if (!Symbol.empty())
ExternalNames.insert(Symbol);
}
}
bool InternalizePass::runOnModule(Module &M) {
CallGraph *CG = getAnalysisIfAvailable<CallGraph>();
CallGraphNode *ExternalNode = CG ? CG->getExternalCallingNode() : 0;
if (ExternalNames.empty()) {
// Return if we're not in 'all but main' mode and have no external api
if (!AllButMain)
return false;
// If no list or file of symbols was specified, check to see if there is a
// "main" symbol defined in the module. If so, use it, otherwise do not
// internalize the module, it must be a library or something.
//
Function *MainFunc = M.getFunction("main");
if (MainFunc == 0 || MainFunc->isDeclaration())
return false; // No main found, must be a library...
// Preserve main, internalize all else.
ExternalNames.insert(MainFunc->getName());
}
bool Changed = false;
// Mark all functions not in the api as internal.
// FIXME: maybe use private linkage?
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
if (!I->isDeclaration() && // Function must be defined here
!I->hasLocalLinkage() && // Can't already have internal linkage
!ExternalNames.count(I->getName())) {// Not marked to keep external?
I->setLinkage(GlobalValue::InternalLinkage);
// Remove a callgraph edge from the external node to this function.
if (ExternalNode) ExternalNode->removeOneAbstractEdgeTo((*CG)[I]);
Changed = true;
++NumFunctions;
DEBUG(dbgs() << "Internalizing func " << I->getName() << "\n");
}
// Never internalize the llvm.used symbol. It is used to implement
// attribute((used)).
// FIXME: Shouldn't this just filter on llvm.metadata section??
ExternalNames.insert("llvm.used");
ExternalNames.insert("llvm.compiler.used");
// Never internalize anchors used by the machine module info, else the info
// won't find them. (see MachineModuleInfo.)
ExternalNames.insert("llvm.dbg.compile_units");
ExternalNames.insert("llvm.dbg.global_variables");
ExternalNames.insert("llvm.dbg.subprograms");
ExternalNames.insert("llvm.global_ctors");
ExternalNames.insert("llvm.global_dtors");
ExternalNames.insert("llvm.noinline");
ExternalNames.insert("llvm.global.annotations");
// Mark all global variables with initializers that are not in the api as
// internal as well.
// FIXME: maybe use private linkage?
for (Module::global_iterator I = M.global_begin(), E = M.global_end();
I != E; ++I)
if (!I->isDeclaration() && !I->hasLocalLinkage() &&
// Available externally is really just a "declaration with a body".
!I->hasAvailableExternallyLinkage() &&
!ExternalNames.count(I->getName())) {
I->setLinkage(GlobalValue::InternalLinkage);
Changed = true;
++NumGlobals;
DEBUG(dbgs() << "Internalized gvar " << I->getName() << "\n");
}
// Mark all aliases that are not in the api as internal as well.
for (Module::alias_iterator I = M.alias_begin(), E = M.alias_end();
I != E; ++I)
if (!I->isDeclaration() && !I->hasInternalLinkage() &&
// Available externally is really just a "declaration with a body".
!I->hasAvailableExternallyLinkage() &&
!ExternalNames.count(I->getName())) {
I->setLinkage(GlobalValue::InternalLinkage);
Changed = true;
++NumAliases;
DEBUG(dbgs() << "Internalized alias " << I->getName() << "\n");
}
return Changed;
}
ModulePass *llvm::createInternalizePass(bool AllButMain) {
return new InternalizePass(AllButMain);
}
ModulePass *llvm::createInternalizePass(const std::vector <const char *> &el) {
return new InternalizePass(el);
}
|
