Chris Lattner | 7311e38 | 2002-07-23 22:03:41 +0000 | [diff] [blame] | 1 | //===- DeadTypeElimination.cpp - Eliminate unused types for symbol table --===// |
Misha Brukman | fd93908 | 2005-04-21 23:48:37 +0000 | [diff] [blame] | 2 | // |
John Criswell | b576c94 | 2003-10-20 19:43:21 +0000 | [diff] [blame] | 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
| 5 | // This file was developed by the LLVM research group and is distributed under |
| 6 | // the University of Illinois Open Source License. See LICENSE.TXT for details. |
Misha Brukman | fd93908 | 2005-04-21 23:48:37 +0000 | [diff] [blame] | 7 | // |
John Criswell | b576c94 | 2003-10-20 19:43:21 +0000 | [diff] [blame] | 8 | //===----------------------------------------------------------------------===// |
Chris Lattner | e51e03b | 2001-10-31 04:33:19 +0000 | [diff] [blame] | 9 | // |
Chris Lattner | 7311e38 | 2002-07-23 22:03:41 +0000 | [diff] [blame] | 10 | // This pass is used to cleanup the output of GCC. It eliminate names for types |
| 11 | // that are unused in the entire translation unit, using the FindUsedTypes pass. |
Chris Lattner | e51e03b | 2001-10-31 04:33:19 +0000 | [diff] [blame] | 12 | // |
| 13 | //===----------------------------------------------------------------------===// |
| 14 | |
Chris Lattner | 86453c5 | 2006-12-19 22:09:18 +0000 | [diff] [blame] | 15 | #define DEBUG_TYPE "deadtypeelim" |
Chris Lattner | 7311e38 | 2002-07-23 22:03:41 +0000 | [diff] [blame] | 16 | #include "llvm/Transforms/IPO.h" |
Chris Lattner | 793c6b8 | 2002-01-31 00:45:11 +0000 | [diff] [blame] | 17 | #include "llvm/Analysis/FindUsedTypes.h" |
Chris Lattner | 793c6b8 | 2002-01-31 00:45:11 +0000 | [diff] [blame] | 18 | #include "llvm/Module.h" |
Reid Spencer | 78d033e | 2007-01-06 07:24:44 +0000 | [diff] [blame] | 19 | #include "llvm/TypeSymbolTable.h" |
Chris Lattner | bfe1110 | 2001-10-31 06:35:59 +0000 | [diff] [blame] | 20 | #include "llvm/DerivedTypes.h" |
Reid Spencer | 551ccae | 2004-09-01 22:55:40 +0000 | [diff] [blame] | 21 | #include "llvm/ADT/Statistic.h" |
Reid Spencer | 9133fe2 | 2007-02-05 23:32:05 +0000 | [diff] [blame] | 22 | #include "llvm/Support/Compiler.h" |
Chris Lattner | 1e2385b | 2003-11-21 21:54:22 +0000 | [diff] [blame] | 23 | using namespace llvm; |
Brian Gaeke | d0fde30 | 2003-11-11 22:41:34 +0000 | [diff] [blame] | 24 | |
Chris Lattner | 86453c5 | 2006-12-19 22:09:18 +0000 | [diff] [blame] | 25 | STATISTIC(NumKilled, "Number of unused typenames removed from symtab"); |
| 26 | |
Chris Lattner | bd0ef77 | 2002-02-26 21:46:54 +0000 | [diff] [blame] | 27 | namespace { |
Reid Spencer | 9133fe2 | 2007-02-05 23:32:05 +0000 | [diff] [blame] | 28 | struct VISIBILITY_HIDDEN DTE : public ModulePass { |
Devang Patel | 1997473 | 2007-05-03 01:11:54 +0000 | [diff] [blame^] | 29 | static char ID; // Pass identifcation, replacement for typeid |
Devang Patel | 794fd75 | 2007-05-01 21:15:47 +0000 | [diff] [blame] | 30 | DTE() : ModulePass((intptr_t)&ID) {} |
| 31 | |
Chris Lattner | bd0ef77 | 2002-02-26 21:46:54 +0000 | [diff] [blame] | 32 | // doPassInitialization - For this pass, it removes global symbol table |
| 33 | // entries for primitive types. These are never used for linking in GCC and |
| 34 | // they make the output uglier to look at, so we nuke them. |
| 35 | // |
| 36 | // Also, initialize instance variables. |
| 37 | // |
Chris Lattner | b12914b | 2004-09-20 04:48:05 +0000 | [diff] [blame] | 38 | bool runOnModule(Module &M); |
Chris Lattner | ce0141e | 2002-06-25 15:55:03 +0000 | [diff] [blame] | 39 | |
Chris Lattner | f57b845 | 2002-04-27 06:56:12 +0000 | [diff] [blame] | 40 | // getAnalysisUsage - This function needs FindUsedTypes to do its job... |
Chris Lattner | bd0ef77 | 2002-02-26 21:46:54 +0000 | [diff] [blame] | 41 | // |
Chris Lattner | f57b845 | 2002-04-27 06:56:12 +0000 | [diff] [blame] | 42 | virtual void getAnalysisUsage(AnalysisUsage &AU) const { |
Chris Lattner | 5f0eb8d | 2002-08-08 19:01:30 +0000 | [diff] [blame] | 43 | AU.addRequired<FindUsedTypes>(); |
Chris Lattner | bd0ef77 | 2002-02-26 21:46:54 +0000 | [diff] [blame] | 44 | } |
| 45 | }; |
Devang Patel | 1997473 | 2007-05-03 01:11:54 +0000 | [diff] [blame^] | 46 | char DTE::ID = 0; |
Chris Lattner | 7f8897f | 2006-08-27 22:42:52 +0000 | [diff] [blame] | 47 | RegisterPass<DTE> X("deadtypeelim", "Dead Type Elimination"); |
Chris Lattner | bd0ef77 | 2002-02-26 21:46:54 +0000 | [diff] [blame] | 48 | } |
| 49 | |
Chris Lattner | b12914b | 2004-09-20 04:48:05 +0000 | [diff] [blame] | 50 | ModulePass *llvm::createDeadTypeEliminationPass() { |
Chris Lattner | 7311e38 | 2002-07-23 22:03:41 +0000 | [diff] [blame] | 51 | return new DTE(); |
Chris Lattner | b6b2692 | 2001-11-03 09:19:00 +0000 | [diff] [blame] | 52 | } |
| 53 | |
| 54 | |
Chris Lattner | b045e14 | 2003-11-09 05:04:25 +0000 | [diff] [blame] | 55 | // ShouldNukeSymtabEntry - Return true if this module level symbol table entry |
Chris Lattner | b6b2692 | 2001-11-03 09:19:00 +0000 | [diff] [blame] | 56 | // should be eliminated. |
| 57 | // |
Chris Lattner | 4f77caa | 2004-02-26 20:02:23 +0000 | [diff] [blame] | 58 | static inline bool ShouldNukeSymtabEntry(const Type *Ty){ |
Chris Lattner | e51e03b | 2001-10-31 04:33:19 +0000 | [diff] [blame] | 59 | // Nuke all names for primitive types! |
Chris Lattner | 42a7551 | 2007-01-15 02:27:26 +0000 | [diff] [blame] | 60 | if (Ty->isPrimitiveType() || Ty->isInteger()) |
Reid Spencer | a54b7cb | 2007-01-12 07:05:14 +0000 | [diff] [blame] | 61 | return true; |
Chris Lattner | e51e03b | 2001-10-31 04:33:19 +0000 | [diff] [blame] | 62 | |
Chris Lattner | 430aa9e | 2001-11-15 04:34:46 +0000 | [diff] [blame] | 63 | // Nuke all pointers to primitive types as well... |
Chris Lattner | 4f77caa | 2004-02-26 20:02:23 +0000 | [diff] [blame] | 64 | if (const PointerType *PT = dyn_cast<PointerType>(Ty)) |
Reid Spencer | a54b7cb | 2007-01-12 07:05:14 +0000 | [diff] [blame] | 65 | if (PT->getElementType()->isPrimitiveType() || |
Chris Lattner | 42a7551 | 2007-01-15 02:27:26 +0000 | [diff] [blame] | 66 | PT->getElementType()->isInteger()) |
Reid Spencer | a54b7cb | 2007-01-12 07:05:14 +0000 | [diff] [blame] | 67 | return true; |
Chris Lattner | 430aa9e | 2001-11-15 04:34:46 +0000 | [diff] [blame] | 68 | |
Chris Lattner | e51e03b | 2001-10-31 04:33:19 +0000 | [diff] [blame] | 69 | return false; |
| 70 | } |
| 71 | |
Chris Lattner | 7311e38 | 2002-07-23 22:03:41 +0000 | [diff] [blame] | 72 | // run - For this pass, it removes global symbol table entries for primitive |
| 73 | // types. These are never used for linking in GCC and they make the output |
| 74 | // uglier to look at, so we nuke them. Also eliminate types that are never used |
| 75 | // in the entire program as indicated by FindUsedTypes. |
Chris Lattner | e51e03b | 2001-10-31 04:33:19 +0000 | [diff] [blame] | 76 | // |
Chris Lattner | b12914b | 2004-09-20 04:48:05 +0000 | [diff] [blame] | 77 | bool DTE::runOnModule(Module &M) { |
Chris Lattner | e51e03b | 2001-10-31 04:33:19 +0000 | [diff] [blame] | 78 | bool Changed = false; |
| 79 | |
Reid Spencer | 78d033e | 2007-01-06 07:24:44 +0000 | [diff] [blame] | 80 | TypeSymbolTable &ST = M.getTypeSymbolTable(); |
Chris Lattner | 4f77caa | 2004-02-26 20:02:23 +0000 | [diff] [blame] | 81 | std::set<const Type *> UsedTypes = getAnalysis<FindUsedTypes>().getTypes(); |
Chris Lattner | 7311e38 | 2002-07-23 22:03:41 +0000 | [diff] [blame] | 82 | |
Chris Lattner | 6e6026b | 2002-11-20 18:36:02 +0000 | [diff] [blame] | 83 | // Check the symbol table for superfluous type entries... |
| 84 | // |
| 85 | // Grab the 'type' plane of the module symbol... |
Reid Spencer | 78d033e | 2007-01-06 07:24:44 +0000 | [diff] [blame] | 86 | TypeSymbolTable::iterator TI = ST.begin(); |
| 87 | TypeSymbolTable::iterator TE = ST.end(); |
| 88 | while ( TI != TE ) { |
Reid Spencer | 9231ac8 | 2004-05-25 08:53:40 +0000 | [diff] [blame] | 89 | // If this entry should be unconditionally removed, or if we detect that |
| 90 | // the type is not used, remove it. |
| 91 | const Type *RHS = TI->second; |
| 92 | if (ShouldNukeSymtabEntry(RHS) || !UsedTypes.count(RHS)) { |
Chris Lattner | 82aa566 | 2005-03-06 05:42:36 +0000 | [diff] [blame] | 93 | ST.remove(TI++); |
Reid Spencer | 9231ac8 | 2004-05-25 08:53:40 +0000 | [diff] [blame] | 94 | ++NumKilled; |
| 95 | Changed = true; |
| 96 | } else { |
| 97 | ++TI; |
| 98 | // We only need to leave one name for each type. |
| 99 | UsedTypes.erase(RHS); |
Chris Lattner | 4f77caa | 2004-02-26 20:02:23 +0000 | [diff] [blame] | 100 | } |
Chris Lattner | 430aa9e | 2001-11-15 04:34:46 +0000 | [diff] [blame] | 101 | } |
Chris Lattner | 7311e38 | 2002-07-23 22:03:41 +0000 | [diff] [blame] | 102 | |
Chris Lattner | e51e03b | 2001-10-31 04:33:19 +0000 | [diff] [blame] | 103 | return Changed; |
| 104 | } |
Reid Spencer | 9231ac8 | 2004-05-25 08:53:40 +0000 | [diff] [blame] | 105 | |
| 106 | // vim: sw=2 |