mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-08-26 07:29:55 +00:00
Also changes the iterators to return actual DI type over MDNode. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204130 91177308-0d34-0410-b5e6-96231b3b80d8
385 lines
12 KiB
C++
385 lines
12 KiB
C++
//===- StripSymbols.cpp - Strip symbols and debug info from a module ------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// The StripSymbols transformation implements code stripping. Specifically, it
|
|
// can delete:
|
|
//
|
|
// * names for virtual registers
|
|
// * symbols for internal globals and functions
|
|
// * debug information
|
|
//
|
|
// 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.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "llvm/Transforms/IPO.h"
|
|
#include "llvm/ADT/DenseMap.h"
|
|
#include "llvm/ADT/SmallPtrSet.h"
|
|
#include "llvm/IR/Constants.h"
|
|
#include "llvm/IR/DebugInfo.h"
|
|
#include "llvm/IR/DerivedTypes.h"
|
|
#include "llvm/IR/Instructions.h"
|
|
#include "llvm/IR/Module.h"
|
|
#include "llvm/IR/TypeFinder.h"
|
|
#include "llvm/IR/ValueSymbolTable.h"
|
|
#include "llvm/Pass.h"
|
|
#include "llvm/Transforms/Utils/Local.h"
|
|
using namespace llvm;
|
|
|
|
namespace {
|
|
class StripSymbols : public ModulePass {
|
|
bool OnlyDebugInfo;
|
|
public:
|
|
static char ID; // Pass identification, replacement for typeid
|
|
explicit StripSymbols(bool ODI = false)
|
|
: ModulePass(ID), OnlyDebugInfo(ODI) {
|
|
initializeStripSymbolsPass(*PassRegistry::getPassRegistry());
|
|
}
|
|
|
|
bool runOnModule(Module &M) override;
|
|
|
|
void getAnalysisUsage(AnalysisUsage &AU) const override {
|
|
AU.setPreservesAll();
|
|
}
|
|
};
|
|
|
|
class StripNonDebugSymbols : public ModulePass {
|
|
public:
|
|
static char ID; // Pass identification, replacement for typeid
|
|
explicit StripNonDebugSymbols()
|
|
: ModulePass(ID) {
|
|
initializeStripNonDebugSymbolsPass(*PassRegistry::getPassRegistry());
|
|
}
|
|
|
|
bool runOnModule(Module &M) override;
|
|
|
|
void getAnalysisUsage(AnalysisUsage &AU) const override {
|
|
AU.setPreservesAll();
|
|
}
|
|
};
|
|
|
|
class StripDebugDeclare : public ModulePass {
|
|
public:
|
|
static char ID; // Pass identification, replacement for typeid
|
|
explicit StripDebugDeclare()
|
|
: ModulePass(ID) {
|
|
initializeStripDebugDeclarePass(*PassRegistry::getPassRegistry());
|
|
}
|
|
|
|
bool runOnModule(Module &M) override;
|
|
|
|
void getAnalysisUsage(AnalysisUsage &AU) const override {
|
|
AU.setPreservesAll();
|
|
}
|
|
};
|
|
|
|
class StripDeadDebugInfo : public ModulePass {
|
|
public:
|
|
static char ID; // Pass identification, replacement for typeid
|
|
explicit StripDeadDebugInfo()
|
|
: ModulePass(ID) {
|
|
initializeStripDeadDebugInfoPass(*PassRegistry::getPassRegistry());
|
|
}
|
|
|
|
bool runOnModule(Module &M) override;
|
|
|
|
void getAnalysisUsage(AnalysisUsage &AU) const override {
|
|
AU.setPreservesAll();
|
|
}
|
|
};
|
|
}
|
|
|
|
char StripSymbols::ID = 0;
|
|
INITIALIZE_PASS(StripSymbols, "strip",
|
|
"Strip all symbols from a module", false, false)
|
|
|
|
ModulePass *llvm::createStripSymbolsPass(bool OnlyDebugInfo) {
|
|
return new StripSymbols(OnlyDebugInfo);
|
|
}
|
|
|
|
char StripNonDebugSymbols::ID = 0;
|
|
INITIALIZE_PASS(StripNonDebugSymbols, "strip-nondebug",
|
|
"Strip all symbols, except dbg symbols, from a module",
|
|
false, false)
|
|
|
|
ModulePass *llvm::createStripNonDebugSymbolsPass() {
|
|
return new StripNonDebugSymbols();
|
|
}
|
|
|
|
char StripDebugDeclare::ID = 0;
|
|
INITIALIZE_PASS(StripDebugDeclare, "strip-debug-declare",
|
|
"Strip all llvm.dbg.declare intrinsics", false, false)
|
|
|
|
ModulePass *llvm::createStripDebugDeclarePass() {
|
|
return new StripDebugDeclare();
|
|
}
|
|
|
|
char StripDeadDebugInfo::ID = 0;
|
|
INITIALIZE_PASS(StripDeadDebugInfo, "strip-dead-debug-info",
|
|
"Strip debug info for unused symbols", false, false)
|
|
|
|
ModulePass *llvm::createStripDeadDebugInfoPass() {
|
|
return new StripDeadDebugInfo();
|
|
}
|
|
|
|
/// OnlyUsedBy - Return true if V is only used by Usr.
|
|
static bool OnlyUsedBy(Value *V, Value *Usr) {
|
|
for (User *U : V->users())
|
|
if (U != Usr)
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
static void RemoveDeadConstant(Constant *C) {
|
|
assert(C->use_empty() && "Constant is not dead!");
|
|
SmallPtrSet<Constant*, 4> Operands;
|
|
for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
|
|
if (OnlyUsedBy(C->getOperand(i), C))
|
|
Operands.insert(cast<Constant>(C->getOperand(i)));
|
|
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(C)) {
|
|
if (!GV->hasLocalLinkage()) return; // Don't delete non-static globals.
|
|
GV->eraseFromParent();
|
|
}
|
|
else if (!isa<Function>(C))
|
|
if (isa<CompositeType>(C->getType()))
|
|
C->destroyConstant();
|
|
|
|
// If the constant referenced anything, see if we can delete it as well.
|
|
for (SmallPtrSet<Constant*, 4>::iterator OI = Operands.begin(),
|
|
OE = Operands.end(); OI != OE; ++OI)
|
|
RemoveDeadConstant(*OI);
|
|
}
|
|
|
|
// Strip the symbol table of its names.
|
|
//
|
|
static void StripSymtab(ValueSymbolTable &ST, bool PreserveDbgInfo) {
|
|
for (ValueSymbolTable::iterator VI = ST.begin(), VE = ST.end(); VI != VE; ) {
|
|
Value *V = VI->getValue();
|
|
++VI;
|
|
if (!isa<GlobalValue>(V) || cast<GlobalValue>(V)->hasLocalLinkage()) {
|
|
if (!PreserveDbgInfo || !V->getName().startswith("llvm.dbg"))
|
|
// Set name to "", removing from symbol table!
|
|
V->setName("");
|
|
}
|
|
}
|
|
}
|
|
|
|
// Strip any named types of their names.
|
|
static void StripTypeNames(Module &M, bool PreserveDbgInfo) {
|
|
TypeFinder StructTypes;
|
|
StructTypes.run(M, false);
|
|
|
|
for (unsigned i = 0, e = StructTypes.size(); i != e; ++i) {
|
|
StructType *STy = StructTypes[i];
|
|
if (STy->isLiteral() || STy->getName().empty()) continue;
|
|
|
|
if (PreserveDbgInfo && STy->getName().startswith("llvm.dbg"))
|
|
continue;
|
|
|
|
STy->setName("");
|
|
}
|
|
}
|
|
|
|
/// Find values that are marked as llvm.used.
|
|
static void findUsedValues(GlobalVariable *LLVMUsed,
|
|
SmallPtrSet<const GlobalValue*, 8> &UsedValues) {
|
|
if (LLVMUsed == 0) return;
|
|
UsedValues.insert(LLVMUsed);
|
|
|
|
ConstantArray *Inits = cast<ConstantArray>(LLVMUsed->getInitializer());
|
|
|
|
for (unsigned i = 0, e = Inits->getNumOperands(); i != e; ++i)
|
|
if (GlobalValue *GV =
|
|
dyn_cast<GlobalValue>(Inits->getOperand(i)->stripPointerCasts()))
|
|
UsedValues.insert(GV);
|
|
}
|
|
|
|
/// StripSymbolNames - Strip symbol names.
|
|
static bool StripSymbolNames(Module &M, bool PreserveDbgInfo) {
|
|
|
|
SmallPtrSet<const GlobalValue*, 8> llvmUsedValues;
|
|
findUsedValues(M.getGlobalVariable("llvm.used"), llvmUsedValues);
|
|
findUsedValues(M.getGlobalVariable("llvm.compiler.used"), llvmUsedValues);
|
|
|
|
for (Module::global_iterator I = M.global_begin(), E = M.global_end();
|
|
I != E; ++I) {
|
|
if (I->hasLocalLinkage() && llvmUsedValues.count(I) == 0)
|
|
if (!PreserveDbgInfo || !I->getName().startswith("llvm.dbg"))
|
|
I->setName(""); // Internal symbols can't participate in linkage
|
|
}
|
|
|
|
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
|
|
if (I->hasLocalLinkage() && llvmUsedValues.count(I) == 0)
|
|
if (!PreserveDbgInfo || !I->getName().startswith("llvm.dbg"))
|
|
I->setName(""); // Internal symbols can't participate in linkage
|
|
StripSymtab(I->getValueSymbolTable(), PreserveDbgInfo);
|
|
}
|
|
|
|
// Remove all names from types.
|
|
StripTypeNames(M, PreserveDbgInfo);
|
|
|
|
return true;
|
|
}
|
|
|
|
bool StripSymbols::runOnModule(Module &M) {
|
|
bool Changed = false;
|
|
Changed |= StripDebugInfo(M);
|
|
if (!OnlyDebugInfo)
|
|
Changed |= StripSymbolNames(M, false);
|
|
return Changed;
|
|
}
|
|
|
|
bool StripNonDebugSymbols::runOnModule(Module &M) {
|
|
return StripSymbolNames(M, true);
|
|
}
|
|
|
|
bool StripDebugDeclare::runOnModule(Module &M) {
|
|
|
|
Function *Declare = M.getFunction("llvm.dbg.declare");
|
|
std::vector<Constant*> DeadConstants;
|
|
|
|
if (Declare) {
|
|
while (!Declare->use_empty()) {
|
|
CallInst *CI = cast<CallInst>(Declare->user_back());
|
|
Value *Arg1 = CI->getArgOperand(0);
|
|
Value *Arg2 = CI->getArgOperand(1);
|
|
assert(CI->use_empty() && "llvm.dbg intrinsic should have void result");
|
|
CI->eraseFromParent();
|
|
if (Arg1->use_empty()) {
|
|
if (Constant *C = dyn_cast<Constant>(Arg1))
|
|
DeadConstants.push_back(C);
|
|
else
|
|
RecursivelyDeleteTriviallyDeadInstructions(Arg1);
|
|
}
|
|
if (Arg2->use_empty())
|
|
if (Constant *C = dyn_cast<Constant>(Arg2))
|
|
DeadConstants.push_back(C);
|
|
}
|
|
Declare->eraseFromParent();
|
|
}
|
|
|
|
while (!DeadConstants.empty()) {
|
|
Constant *C = DeadConstants.back();
|
|
DeadConstants.pop_back();
|
|
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(C)) {
|
|
if (GV->hasLocalLinkage())
|
|
RemoveDeadConstant(GV);
|
|
} else
|
|
RemoveDeadConstant(C);
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
/// Remove any debug info for global variables/functions in the given module for
|
|
/// which said global variable/function no longer exists (i.e. is null).
|
|
///
|
|
/// Debugging information is encoded in llvm IR using metadata. This is designed
|
|
/// such a way that debug info for symbols preserved even if symbols are
|
|
/// optimized away by the optimizer. This special pass removes debug info for
|
|
/// such symbols.
|
|
bool StripDeadDebugInfo::runOnModule(Module &M) {
|
|
bool Changed = false;
|
|
|
|
LLVMContext &C = M.getContext();
|
|
|
|
// Find all debug info in F. This is actually overkill in terms of what we
|
|
// want to do, but we want to try and be as resilient as possible in the face
|
|
// of potential debug info changes by using the formal interfaces given to us
|
|
// as much as possible.
|
|
DebugInfoFinder F;
|
|
F.processModule(M);
|
|
|
|
// For each compile unit, find the live set of global variables/functions and
|
|
// replace the current list of potentially dead global variables/functions
|
|
// with the live list.
|
|
SmallVector<Value *, 64> LiveGlobalVariables;
|
|
SmallVector<Value *, 64> LiveSubprograms;
|
|
DenseSet<const MDNode *> VisitedSet;
|
|
|
|
for (DICompileUnit DIC : F.compile_units()) {
|
|
assert(DIC.Verify() && "DIC must verify as a DICompileUnit.");
|
|
|
|
// Create our live subprogram list.
|
|
DIArray SPs = DIC.getSubprograms();
|
|
bool SubprogramChange = false;
|
|
for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i) {
|
|
DISubprogram DISP(SPs.getElement(i));
|
|
assert(DISP.Verify() && "DISP must verify as a DISubprogram.");
|
|
|
|
// Make sure we visit each subprogram only once.
|
|
if (!VisitedSet.insert(DISP).second)
|
|
continue;
|
|
|
|
// If the function referenced by DISP is not null, the function is live.
|
|
if (DISP.getFunction())
|
|
LiveSubprograms.push_back(DISP);
|
|
else
|
|
SubprogramChange = true;
|
|
}
|
|
|
|
// Create our live global variable list.
|
|
DIArray GVs = DIC.getGlobalVariables();
|
|
bool GlobalVariableChange = false;
|
|
for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i) {
|
|
DIGlobalVariable DIG(GVs.getElement(i));
|
|
assert(DIG.Verify() && "DIG must verify as DIGlobalVariable.");
|
|
|
|
// Make sure we only visit each global variable only once.
|
|
if (!VisitedSet.insert(DIG).second)
|
|
continue;
|
|
|
|
// If the global variable referenced by DIG is not null, the global
|
|
// variable is live.
|
|
if (DIG.getGlobal())
|
|
LiveGlobalVariables.push_back(DIG);
|
|
else
|
|
GlobalVariableChange = true;
|
|
}
|
|
|
|
// If we found dead subprograms or global variables, replace the current
|
|
// subprogram list/global variable list with our new live subprogram/global
|
|
// variable list.
|
|
if (SubprogramChange) {
|
|
// Make sure that 9 is still the index of the subprograms. This is to make
|
|
// sure that an assert is hit if the location of the subprogram array
|
|
// changes. This is just to make sure that this is updated if such an
|
|
// event occurs.
|
|
assert(DIC->getNumOperands() >= 10 &&
|
|
SPs == DIC->getOperand(9) &&
|
|
"DICompileUnits is expected to store Subprograms in operand "
|
|
"9.");
|
|
DIC->replaceOperandWith(9, MDNode::get(C, LiveSubprograms));
|
|
Changed = true;
|
|
}
|
|
|
|
if (GlobalVariableChange) {
|
|
// Make sure that 10 is still the index of global variables. This is to
|
|
// make sure that an assert is hit if the location of the subprogram array
|
|
// changes. This is just to make sure that this index is updated if such
|
|
// an event occurs.
|
|
assert(DIC->getNumOperands() >= 11 &&
|
|
GVs == DIC->getOperand(10) &&
|
|
"DICompileUnits is expected to store Global Variables in operand "
|
|
"10.");
|
|
DIC->replaceOperandWith(10, MDNode::get(C, LiveGlobalVariables));
|
|
Changed = true;
|
|
}
|
|
|
|
// Reset lists for the next iteration.
|
|
LiveSubprograms.clear();
|
|
LiveGlobalVariables.clear();
|
|
}
|
|
|
|
return Changed;
|
|
}
|