Remove attribution from file headers, per discussion on llvmdev.

[oota-llvm.git] / lib / Transforms / IPO / StripSymbols.cpp

diff --git a/lib/Transforms/IPO/StripSymbols.cpp b/lib/Transforms/IPO/StripSymbols.cpp
index da5e8a4844ae007321f783e56e9aa114738e2562..9427eb67824fef300e17ba75be960d3c26ab7226 100644 (file)
--- a/lib/Transforms/IPO/StripSymbols.cpp
+++ b/lib/Transforms/IPO/StripSymbols.cpp
@@ -2,23 +2,21 @@
 //
 //                     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 file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
-// This file implements stripping symbols out of symbol tables.
+// The StripSymbols transformation implements code stripping. Specifically, it
+// can delete:
+// 
+//   * names for virtual registers
+//   * symbols for internal globals and functions
+//   * debug information
 //
-// Specifically, this allows you to strip all of the symbols out of:
-//   * All functions in a module
-//   * All non-essential symbols in a module (all function symbols + all module
-//     scope symbols)
-//   * Debug information.
-//
-// Notice that:
-//   * This pass makes code much less readable, so it should only be used in
-//     situations where the 'strip' utility would be used (such as reducing
-//     code size, and making it harder to reverse engineer code).
+// Note that this transformation makes code much less readable, so it should
+// only be used in situations where the 'strip' utility would be used, such as
+// reducing code size or making it harder to reverse engineer code.
 //
 //===----------------------------------------------------------------------===//
 
@@ -28,14 +26,18 @@
 #include "llvm/Instructions.h"
 #include "llvm/Module.h"
 #include "llvm/Pass.h"
-#include "llvm/SymbolTable.h"
+#include "llvm/ValueSymbolTable.h"
+#include "llvm/TypeSymbolTable.h"
+#include "llvm/Support/Compiler.h"
 using namespace llvm;
 
 namespace {
-  class StripSymbols : public ModulePass {
+  class VISIBILITY_HIDDEN StripSymbols : public ModulePass {
     bool OnlyDebugInfo;
   public:
-    StripSymbols(bool ODI = false) : OnlyDebugInfo(ODI) {}
+    static char ID; // Pass identification, replacement for typeid
+    explicit StripSymbols(bool ODI = false) 
+      : ModulePass((intptr_t)&ID), OnlyDebugInfo(ODI) {}
 
     virtual bool runOnModule(Module &M);
 
@@ -43,7 +45,9 @@ namespace {
       AU.setPreservesAll();
     }
   };
-  RegisterOpt<StripSymbols> X("strip", "Strip all symbols from a module");
+
+  char StripSymbols::ID = 0;
+  RegisterPass<StripSymbols> X("strip", "Strip all symbols from a module");
 }
 
 ModulePass *llvm::createStripSymbolsPass(bool OnlyDebugInfo) {
@@ -71,34 +75,54 @@ static void RemoveDeadConstant(Constant *C) {
   }
 }
 
+// Strip the symbol table of its names.
+//
+static void StripSymtab(ValueSymbolTable &ST) {
+  for (ValueSymbolTable::iterator VI = ST.begin(), VE = ST.end(); VI != VE; ) {
+    Value *V = VI->getValue();
+    ++VI;
+    if (!isa<GlobalValue>(V) || cast<GlobalValue>(V)->hasInternalLinkage()) {
+      // Set name to "", removing from symbol table!
+      V->setName("");
+    }
+  }
+}
+
+// Strip the symbol table of its names.
+static void StripTypeSymtab(TypeSymbolTable &ST) {
+  for (TypeSymbolTable::iterator TI = ST.begin(), E = ST.end(); TI != E; )
+    ST.remove(TI++);
+}
+
+
+
 bool StripSymbols::runOnModule(Module &M) {
   // If we're not just stripping debug info, strip all symbols from the
   // functions and the names from any internal globals.
   if (!OnlyDebugInfo) {
-    for (Module::global_iterator I = M.global_begin(), E = M.global_end(); I != E; ++I)
+    for (Module::global_iterator I = M.global_begin(), E = M.global_end();
+         I != E; ++I)
       if (I->hasInternalLinkage())
         I->setName("");     // Internal symbols can't participate in linkage
 
     for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
       if (I->hasInternalLinkage())
         I->setName("");     // Internal symbols can't participate in linkage
-      I->getSymbolTable().strip();
+      StripSymtab(I->getValueSymbolTable());
     }
     
     // Remove all names from types.
-    SymbolTable &SymTab = M.getSymbolTable();
-    while (SymTab.type_begin() != SymTab.type_end())
-      SymTab.remove(SymTab.type_begin());
+    StripTypeSymtab(M.getTypeSymbolTable());
   }
 
   // Strip debug info in the module if it exists.  To do this, we remove
   // llvm.dbg.func.start, llvm.dbg.stoppoint, and llvm.dbg.region.end calls, and
   // any globals they point to if now dead.
-  Function *FuncStart = M.getNamedFunction("llvm.dbg.func.start");
-  Function *StopPoint = M.getNamedFunction("llvm.dbg.stoppoint");
-  Function *RegionStart = M.getNamedFunction("llvm.dbg.region.start");
-  Function *RegionEnd = M.getNamedFunction("llvm.dbg.region.end");
-  Function *Declare = M.getNamedFunction("llvm.dbg.declare");
+  Function *FuncStart = M.getFunction("llvm.dbg.func.start");
+  Function *StopPoint = M.getFunction("llvm.dbg.stoppoint");
+  Function *RegionStart = M.getFunction("llvm.dbg.region.start");
+  Function *RegionEnd = M.getFunction("llvm.dbg.region.end");
+  Function *Declare = M.getFunction("llvm.dbg.declare");
   if (!FuncStart && !StopPoint && !RegionStart && !RegionEnd && !Declare)
     return true;