-//===- CleanupGCCOutput.cpp - Cleanup GCC Output --------------------------===//
+//===- DeadTypeElimination.cpp - Eliminate unused types for symbol table --===//
//
-// This pass is used to cleanup the output of GCC. GCC's output is
-// unneccessarily gross for a couple of reasons. This pass does the following
-// things to try to clean it up:
-//
-// * Eliminate names for GCC types that we know can't be needed by the user.
-// * Eliminate names for types that are unused in the entire translation unit
-// * Fix various problems that we might have in PHI nodes and casts
-//
-// Note: This code produces dead declarations, it is a good idea to run DCE
-// after this pass.
+// This pass is used to cleanup the output of GCC. It eliminate names for types
+// that are unused in the entire translation unit, using the FindUsedTypes pass.
//
//===----------------------------------------------------------------------===//
-#include "llvm/Transforms/CleanupGCCOutput.h"
+#include "llvm/Transforms/IPO.h"
#include "llvm/Analysis/FindUsedTypes.h"
#include "llvm/Module.h"
#include "llvm/SymbolTable.h"
#include "llvm/DerivedTypes.h"
-#include "llvm/iPHINode.h"
-#include "llvm/iMemory.h"
-#include "llvm/iTerminators.h"
-#include "llvm/iOther.h"
-#include "llvm/Support/CFG.h"
-#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "Support/StatisticReporter.h"
-#include <algorithm>
-#include <iostream>
-
-static Statistic<> NumTypeSymtabEntriesKilled("cleangcc\t- Number of unused typenames removed from symtab");
using std::vector;
namespace {
- struct CleanupGCCOutput : public FunctionPass {
- const char *getPassName() const { return "Cleanup GCC Output"; }
-
+ struct DTE : public Pass {
// doPassInitialization - For this pass, it removes global symbol table
// entries for primitive types. These are never used for linking in GCC and
// they make the output uglier to look at, so we nuke them.
//
// Also, initialize instance variables.
//
- bool doInitialization(Module &M);
+ bool run(Module &M);
- // FIXME:
- // FIXME: This FunctionPass should be a PASS!
- // FIXME:
- bool runOnFunction(Function &F) { return false; }
-
- // doPassFinalization - Strip out type names that are unused by the program
- bool doFinalization(Module &M);
-
// getAnalysisUsage - This function needs FindUsedTypes to do its job...
//
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
- AU.addRequired(FindUsedTypes::ID);
+ AU.addRequired<FindUsedTypes>();
}
};
+ RegisterOpt<DTE> X("deadtypeelim", "Dead Type Elimination");
+ Statistic<> NumKilled("deadtypeelim\t- Number of unused typenames removed from symtab");
}
-Pass *createCleanupGCCOutputPass() {
- return new CleanupGCCOutput();
+Pass *createDeadTypeEliminationPass() {
+ return new DTE();
}
return false;
}
-// doInitialization - For this pass, it removes global symbol table
-// entries for primitive types. These are never used for linking in GCC and
-// they make the output uglier to look at, so we nuke them.
+// run - For this pass, it removes global symbol table entries for primitive
+// types. These are never used for linking in GCC and they make the output
+// uglier to look at, so we nuke them. Also eliminate types that are never used
+// in the entire program as indicated by FindUsedTypes.
//
-bool CleanupGCCOutput::doInitialization(Module &M) {
- bool Changed = false;
-
- if (SymbolTable *ST = M.getSymbolTable()) {
- // Check the symbol table for superfluous type entries...
- //
- // Grab the 'type' plane of the module symbol...
- SymbolTable::iterator STI = ST->find(Type::TypeTy);
- if (STI != ST->end()) {
- // Loop over all entries in the type plane...
- SymbolTable::VarMap &Plane = STI->second;
- for (SymbolTable::VarMap::iterator PI = Plane.begin(); PI != Plane.end();)
- if (ShouldNukeSymtabEntry(*PI)) { // Should we remove this entry?
-#if MAP_IS_NOT_BRAINDEAD
- PI = Plane.erase(PI); // STD C++ Map should support this!
-#else
- Plane.erase(PI); // Alas, GCC 2.95.3 doesn't *SIGH*
- PI = Plane.begin();
-#endif
- ++NumTypeSymtabEntriesKilled;
- Changed = true;
- } else {
- ++PI;
- }
- }
- }
-
- return Changed;
-}
-
-
-bool CleanupGCCOutput::doFinalization(Module &M) {
+bool DTE::run(Module &M) {
bool Changed = false;
if (SymbolTable *ST = M.getSymbolTable()) {
const std::set<const Type *> &UsedTypes =
getAnalysis<FindUsedTypes>().getTypes();
- // Check the symbol table for superfluous type entries that aren't used in
- // the program
+ // Check the symbol table for superfluous type entries...
//
// Grab the 'type' plane of the module symbol...
SymbolTable::iterator STI = ST->find(Type::TypeTy);
// Loop over all entries in the type plane...
SymbolTable::VarMap &Plane = STI->second;
for (SymbolTable::VarMap::iterator PI = Plane.begin(); PI != Plane.end();)
- if (!UsedTypes.count(cast<Type>(PI->second))) {
+ // If this entry should be unconditionally removed, or if we detect that
+ // the type is not used, remove it.
+ //
+ if (ShouldNukeSymtabEntry(*PI) ||
+ !UsedTypes.count(cast<Type>(PI->second))) {
#if MAP_IS_NOT_BRAINDEAD
PI = Plane.erase(PI); // STD C++ Map should support this!
#else
Plane.erase(PI); // Alas, GCC 2.95.3 doesn't *SIGH*
- PI = Plane.begin(); // N^2 algorithms are fun. :(
+ PI = Plane.begin();
#endif
+ ++NumKilled;
Changed = true;
} else {
++PI;
}
}
}
+
return Changed;
}
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