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Chris Lattner1b94c002002-04-28 05:43:27 +00001//===-- Internalize.cpp - Mark functions internal -------------------------===//
2//
3// This pass loops over all of the functions in the input module, looking for a
Chris Lattner47cc3662002-07-30 19:48:44 +00004// main function. If a main function is found, all other functions and all
5// global variables with initializers are marked as internal.
Chris Lattner1b94c002002-04-28 05:43:27 +00006//
7//===----------------------------------------------------------------------===//
8
Chris Lattner99a53f62002-07-24 17:12:05 +00009#include "llvm/Transforms/IPO.h"
Chris Lattner1b94c002002-04-28 05:43:27 +000010#include "llvm/Pass.h"
11#include "llvm/Module.h"
Chris Lattnerbf3a0992002-10-01 22:38:41 +000012#include "Support/Statistic.h"
Chris Lattner0b18c1d2002-05-10 15:38:35 +000013
Chris Lattnerb28b6802002-07-23 18:06:35 +000014namespace {
Chris Lattnerbf3a0992002-10-01 22:38:41 +000015 Statistic<> NumFunctions("internalize", "Number of functions internalized");
16 Statistic<> NumGlobals ("internalize", "Number of global vars internalized");
Chris Lattner1b94c002002-04-28 05:43:27 +000017
Chris Lattner47cc3662002-07-30 19:48:44 +000018 class InternalizePass : public Pass {
19 virtual bool run(Module &M) {
20 bool FoundMain = false; // Look for a function named main...
21 for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
22 if (I->getName() == "main" && !I->isExternal() &&
23 I->hasExternalLinkage()) {
24 FoundMain = true;
25 break;
26 }
27
28 if (!FoundMain) return false; // No main found, must be a library...
29
30 bool Changed = false;
31
32 // Found a main function, mark all functions not named main as internal.
33 for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
34 if (I->getName() != "main" && // Leave the main function external
35 !I->isExternal() && // Function must be defined here
36 !I->hasInternalLinkage()) { // Can't already have internal linkage
37 I->setInternalLinkage(true);
38 Changed = true;
39 ++NumFunctions;
40 DEBUG(std::cerr << "Internalizing func " << I->getName() << "\n");
41 }
Chris Lattner1b94c002002-04-28 05:43:27 +000042
Chris Lattner47cc3662002-07-30 19:48:44 +000043 // Mark all global variables with initializers as internal as well...
44 for (Module::giterator I = M.gbegin(), E = M.gend(); I != E; ++I)
Chris Lattner68f21bc2002-10-07 18:34:32 +000045 if (!I->isExternal() && I->hasExternalLinkage()) {
Chris Lattner47cc3662002-07-30 19:48:44 +000046 I->setInternalLinkage(true);
47 Changed = true;
48 ++NumGlobals;
49 DEBUG(std::cerr << "Internalizing gvar " << I->getName() << "\n");
50 }
51
52 return Changed;
53 }
54 };
Chris Lattner1b94c002002-04-28 05:43:27 +000055
Chris Lattnera2c09852002-07-26 21:12:44 +000056 RegisterOpt<InternalizePass> X("internalize", "Internalize Functions");
Chris Lattnerb28b6802002-07-23 18:06:35 +000057} // end anonymous namespace
58
Chris Lattner1b94c002002-04-28 05:43:27 +000059Pass *createInternalizePass() {
60 return new InternalizePass();
61}