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Diffstat (limited to 'contrib/llvm/lib/Transforms/IPO/Internalize.cpp')
-rw-r--r-- | contrib/llvm/lib/Transforms/IPO/Internalize.cpp | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Transforms/IPO/Internalize.cpp b/contrib/llvm/lib/Transforms/IPO/Internalize.cpp new file mode 100644 index 0000000..47abb7d --- /dev/null +++ b/contrib/llvm/lib/Transforms/IPO/Internalize.cpp @@ -0,0 +1,190 @@ +//===-- 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; +static RegisterPass<InternalizePass> +X("internalize", "Internalize Global Symbols"); + +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); +} |