1 //===-- Internalize.cpp - Mark functions internal -------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This pass loops over all of the functions and variables in the input module.
11 // If the function or variable is not in the list of external names given to
12 // the pass it is marked as internal.
14 //===----------------------------------------------------------------------===//
16 #define DEBUG_TYPE "internalize"
17 #include "llvm/Analysis/CallGraph.h"
18 #include "llvm/Transforms/IPO.h"
19 #include "llvm/Pass.h"
20 #include "llvm/Module.h"
21 #include "llvm/Support/CommandLine.h"
22 #include "llvm/Support/Debug.h"
23 #include "llvm/Support/raw_ostream.h"
24 #include "llvm/ADT/Statistic.h"
29 STATISTIC(NumAliases , "Number of aliases internalized");
30 STATISTIC(NumFunctions, "Number of functions internalized");
31 STATISTIC(NumGlobals , "Number of global vars internalized");
33 // APIFile - A file which contains a list of symbols that should not be marked
35 static cl::opt<std::string>
36 APIFile("internalize-public-api-file", cl::value_desc("filename"),
37 cl::desc("A file containing list of symbol names to preserve"));
39 // APIList - A list of symbols that should not be marked internal.
40 static cl::list<std::string>
41 APIList("internalize-public-api-list", cl::value_desc("list"),
42 cl::desc("A list of symbol names to preserve"),
46 class InternalizePass : public ModulePass {
47 std::set<std::string> ExternalNames;
49 static char ID; // Pass identification, replacement for typeid
50 explicit InternalizePass();
51 explicit InternalizePass(const std::vector <const char *>& exportList);
52 void LoadFile(const char *Filename);
53 virtual bool runOnModule(Module &M);
55 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
57 AU.addPreserved<CallGraph>();
60 } // end anonymous namespace
62 char InternalizePass::ID = 0;
63 INITIALIZE_PASS(InternalizePass, "internalize",
64 "Internalize Global Symbols", false, false)
66 InternalizePass::InternalizePass()
68 initializeInternalizePassPass(*PassRegistry::getPassRegistry());
69 if (!APIFile.empty()) // If a filename is specified, use it.
70 LoadFile(APIFile.c_str());
71 if (!APIList.empty()) // If a list is specified, use it as well.
72 ExternalNames.insert(APIList.begin(), APIList.end());
75 InternalizePass::InternalizePass(const std::vector<const char *>&exportList)
77 initializeInternalizePassPass(*PassRegistry::getPassRegistry());
78 for(std::vector<const char *>::const_iterator itr = exportList.begin();
79 itr != exportList.end(); itr++) {
80 ExternalNames.insert(*itr);
84 void InternalizePass::LoadFile(const char *Filename) {
85 // Load the APIFile...
86 std::ifstream In(Filename);
88 errs() << "WARNING: Internalize couldn't load file '" << Filename
89 << "'! Continuing as if it's empty.\n";
90 return; // Just continue as if the file were empty
96 ExternalNames.insert(Symbol);
100 bool InternalizePass::runOnModule(Module &M) {
101 CallGraph *CG = getAnalysisIfAvailable<CallGraph>();
102 CallGraphNode *ExternalNode = CG ? CG->getExternalCallingNode() : 0;
103 bool Changed = false;
105 // Never internalize functions which code-gen might insert.
106 // FIXME: We should probably add this (and the __stack_chk_guard) via some
107 // type of call-back in CodeGen.
108 ExternalNames.insert("__stack_chk_fail");
110 // Mark all functions not in the api as internal.
111 // FIXME: maybe use private linkage?
112 for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
113 if (!I->isDeclaration() && // Function must be defined here
114 // Available externally is really just a "declaration with a body".
115 !I->hasAvailableExternallyLinkage() &&
116 !I->hasLocalLinkage() && // Can't already have internal linkage
117 !ExternalNames.count(I->getName())) {// Not marked to keep external?
118 I->setLinkage(GlobalValue::InternalLinkage);
119 // Remove a callgraph edge from the external node to this function.
120 if (ExternalNode) ExternalNode->removeOneAbstractEdgeTo((*CG)[I]);
123 DEBUG(dbgs() << "Internalizing func " << I->getName() << "\n");
126 // Never internalize the llvm.used symbol. It is used to implement
127 // attribute((used)).
128 // FIXME: Shouldn't this just filter on llvm.metadata section??
129 ExternalNames.insert("llvm.used");
130 ExternalNames.insert("llvm.compiler.used");
132 // Never internalize anchors used by the machine module info, else the info
133 // won't find them. (see MachineModuleInfo.)
134 ExternalNames.insert("llvm.global_ctors");
135 ExternalNames.insert("llvm.global_dtors");
136 ExternalNames.insert("llvm.global.annotations");
138 // Never internalize symbols code-gen inserts.
139 ExternalNames.insert("__stack_chk_guard");
141 // Mark all global variables with initializers that are not in the api as
143 // FIXME: maybe use private linkage?
144 for (Module::global_iterator I = M.global_begin(), E = M.global_end();
146 if (!I->isDeclaration() && !I->hasLocalLinkage() &&
147 // Available externally is really just a "declaration with a body".
148 !I->hasAvailableExternallyLinkage() &&
149 !ExternalNames.count(I->getName())) {
150 I->setLinkage(GlobalValue::InternalLinkage);
153 DEBUG(dbgs() << "Internalized gvar " << I->getName() << "\n");
156 // Mark all aliases that are not in the api as internal as well.
157 for (Module::alias_iterator I = M.alias_begin(), E = M.alias_end();
159 if (!I->isDeclaration() && !I->hasInternalLinkage() &&
160 // Available externally is really just a "declaration with a body".
161 !I->hasAvailableExternallyLinkage() &&
162 !ExternalNames.count(I->getName())) {
163 I->setLinkage(GlobalValue::InternalLinkage);
166 DEBUG(dbgs() << "Internalized alias " << I->getName() << "\n");
172 ModulePass *llvm::createInternalizePass() {
173 return new InternalizePass();
176 ModulePass *llvm::createInternalizePass(const std::vector <const char *> &el) {
177 return new InternalizePass(el);