//===-- 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 are marked
-// as internal.
+// main function. If a main function is found, all other functions and all
+// global variables with initializers are marked as internal.
//
//===----------------------------------------------------------------------===//
-#include "llvm/Transforms/IPO/Internalize.h"
+#define DEBUG_TYPE "internalize"
+#include "llvm/Analysis/CallGraph.h"
+#include "llvm/Transforms/IPO.h"
#include "llvm/Pass.h"
#include "llvm/Module.h"
-#include "llvm/Function.h"
-#include "Support/StatisticReporter.h"
-
-static Statistic<> NumChanged("internalize\t- Number of functions internal'd");
-
-class InternalizePass : public Pass {
- const char *getPassName() const { return "Internalize Functions"; }
-
- virtual bool run(Module &M) {
- bool FoundMain = false; // Look for a function named main...
- for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
- if (I->getName() == "main" && !I->isExternal()) {
- FoundMain = true;
- break;
- }
-
- if (!FoundMain) return false; // No main found, must be a library...
-
- bool Changed = false;
-
- // Found a main function, mark all functions not named main as internal.
- for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
- if (I->getName() != "main" && // Leave the main function external
- !I->isExternal()) { // Function must be defined here
- I->setInternalLinkage(true);
- Changed = true;
- ++NumChanged;
- }
-
- return Changed;
+#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){
+ initializeInternalizePassPass(*PassRegistry::getPassRegistry());
+ 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){
+ initializeInternalizePassPass(*PassRegistry::getPassRegistry());
+ 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;
+
+ // Never internalize functions which code-gen might insert.
+ // FIXME: We should probably add this (and the __stack_chk_guard) via some
+ // type of call-back in CodeGen.
+ ExternalNames.insert("__stack_chk_fail");
+
+ // 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
+ // Available externally is really just a "declaration with a body".
+ !I->hasAvailableExternallyLinkage() &&
+ !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.global_ctors");
+ ExternalNames.insert("llvm.global_dtors");
+ ExternalNames.insert("llvm.global.annotations");
+
+ // Never internalize symbols code-gen inserts.
+ ExternalNames.insert("__stack_chk_guard");
+
+ // 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);
+}
-Pass *createInternalizePass() {
- return new InternalizePass();
+ModulePass *llvm::createInternalizePass(const std::vector <const char *> &el) {
+ return new InternalizePass(el);
}