1 files changed, 128 insertions, 0 deletions
diff --git a/lib/Transforms/IPO/Internalize.cpp b/lib/Transforms/IPO/Internalize.cpp
new file mode 100644
index 0000000000..eeee63b989
--- /dev/null
+++ b/lib/Transforms/IPO/Internalize.cpp
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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 ModulePass {
+    std::set<std::string> ExternalNames;
+    bool DontInternalize;
+  public:
+    InternalizePass(bool InternalizeEverything = true) : DontInternalize(false){
+      if (!APIFile.empty())           // If a filename is specified, use it
+        LoadFile(APIFile.c_str());
+      else if (!APIList.empty())      // Else, if a list is specified, use it.
+        ExternalNames.insert(APIList.begin(), APIList.end());
+      else if (!InternalizeEverything)
+        // Finally, if we're allowed to, internalize all but main.
+        DontInternalize = true;
+    }
+
+    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 runOnModule(Module &M) {
+      if (DontInternalize) 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.
+      //
+      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::global_iterator I = M.global_begin(), E = M.global_end(); 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
+
+ModulePass *llvm::createInternalizePass(bool InternalizeEverything) {
+  return new InternalizePass(InternalizeEverything);
+}