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//===-- Internalize.cpp - Mark functions internal -------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and 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.
//
//===----------------------------------------------------------------------===//
#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/ADT/Statistic.h"
#include <fstream>
#include <set>
using namespace llvm;
namespace {
Statistic<> NumFunctions("internalize", "Number of functions internalized");
Statistic<> NumGlobals ("internalize", "Number of global vars internalized");
// APIFile - A file which contains a list of symbols that should not be marked
// external.
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.
cl::list<std::string>
APIList("internalize-public-api-list", cl::value_desc("list"),
cl::desc("A list of symbol names to preserve"),
cl::CommaSeparated);
class InternalizePass : public Pass {
std::set<std::string> ExternalNames;
public:
InternalizePass() {
if (!APIFile.empty()) // If a filename is specified, use it
LoadFile(APIFile.c_str());
else // Else, if a list is specified, use it.
ExternalNames.insert(APIList.begin(), APIList.end());
}
void LoadFile(const char *Filename) {
// Load the APIFile...
std::ifstream In(Filename);
if (!In.good()) {
std::cerr << "WARNING: Internalize couldn't load file '" << Filename
<< "'!\n";
return; // Do not internalize anything...
}
while (In) {
std::string Symbol;
In >> Symbol;
if (!Symbol.empty())
ExternalNames.insert(Symbol);
}
}
virtual bool run(Module &M) {
// 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.
//
if (ExternalNames.empty()) {
Function *MainFunc = M.getMainFunction();
if (MainFunc == 0 || MainFunc->isExternal())
return false; // No main found, must be a library...
// Preserve main, internalize all else.
ExternalNames.insert(MainFunc->getName());
}
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->isExternal() && // Function must be defined here
!I->hasInternalLinkage() && // Can't already have internal linkage
!ExternalNames.count(I->getName())) {// Not marked to keep external?
I->setLinkage(GlobalValue::InternalLinkage);
Changed = true;
++NumFunctions;
DEBUG(std::cerr << "Internalizing func " << I->getName() << "\n");
}
// Mark all global variables with initializers as internal as well...
for (Module::giterator I = M.gbegin(), E = M.gend(); I != E; ++I)
if (!I->isExternal() && !I->hasInternalLinkage() &&
!ExternalNames.count(I->getName())) {
// Special case handling of the global ctor and dtor list. When we
// internalize it, we mark it constant, which allows elimination of
// the list if it's empty.
//
if (I->hasAppendingLinkage() && (I->getName() == "llvm.global_ctors"||
I->getName() == "llvm.global_dtors"))
I->setConstant(true);
I->setLinkage(GlobalValue::InternalLinkage);
Changed = true;
++NumGlobals;
DEBUG(std::cerr << "Internalizing gvar " << I->getName() << "\n");
}
return Changed;
}
};
RegisterOpt<InternalizePass> X("internalize", "Internalize Global Symbols");
} // end anonymous namespace
Pass *llvm::createInternalizePass() {
return new InternalizePass();
}
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