Hi!
I'm having some trouble with a pass I'm writing.
I'm using DemotePHIToStack to remove all phi node in my code with this code (this is the first thing I do in my pass):
// Erase phi node
vector<PHINode*> phis;
for (Function::iterator i=f->begin();i!=f->end();++i) {
for(BasicBlock::iterator b=i->begin();b!=i->end();++b) {
if(isa<PHINode>(b)) {
PHINode *phi= cast<PHINode>(b);
phis.push_back(phi);
}
}
}
for(vector<PHINode*>::iterator i=phis.begin();i!=phis.end();++i) {
PHINode *phi = *i;
DemotePHIToStack(phi,NULL);
}
If I only run this code, I obtain this code (see safer.phi.ll).
If I run the rest of my pass, I obtain this code (see safer.phi.obfu.ll)
And I got this error for the file safer.phi.obfu.ll:
Instruction does not dominate all uses!
%18 = load i8** %key.addr, align 8, !dbg !322
call void @Safer_Expand_Userkey(i8* %18, i8* %19, i32 %cond.reload, i32 0, i8* %arraydecay), !dbg !322
Instruction does not dominate all uses!
%19 = load i8** %key.addr, align 8, !dbg !322
call void @Safer_Expand_Userkey(i8* %18, i8* %19, i32 %cond.reload, i32 0, i8* %arraydecay), !dbg !322
Broken module found, compilation aborted!
0 opt 0x0000000000946d3f
1 opt 0x0000000000947229
2 libpthread.so.0 0x00007fcba9ff2170
3 libc.so.6 0x00007fcba925dfa5 gsignal + 53
4 libc.so.6 0x00007fcba925f428 abort + 328
5 opt 0x000000000090951d
6 opt 0x00000000008e609f llvm::FPPassManager::runOnFunction(llvm::Function&) + 607
7 opt 0x00000000008e60f3 llvm::FPPassManager::runOnModule(llvm::Module&) + 51
8 opt 0x00000000008e5c6c llvm::MPPassManager::runOnModule(llvm::Module&) + 524
9 opt 0x00000000008e5d77 llvm::PassManagerImpl::run(llvm::Module&) + 151
10 opt 0x00000000004a1d99 main + 3385
11 libc.so.6 0x00007fcba924a725 __libc_start_main + 245
12 opt 0x00000000004a6135
Stack dump:
0. Program arguments: opt -load ../../../build/Release+Asserts/lib/LLVMobfuscation.so -flattening src/ciphers/safer/safer.bc -o src/ciphers/safer/safer.bc -stats
1. Running pass 'Function Pass Manager' on module 'src/ciphers/safer/safer.bc'.
2. Running pass 'Module Verifier' on function '@safer_k64_setup'
make: *** [src/ciphers/safer/safer.o] Aborted
So the problem come from the bloc if.end11 and cond.end. I understand the dominate problem, but the thing is that these instruction (in first file):
if.end11: ; preds = %if.end8
%6 = load i8** %key.addr, align 8, !dbg !322
%7 = load i8** %key.addr, align 8, !dbg !322
...
cond.end: ; preds = %cond.false, %cond.true
%cond.reload = load i32* %cond.reg2mem
%10 = load %union.Symmetric_key** %skey.addr, align 8, !dbg !322
%safer = bitcast %union.Symmetric_key* %10 to %struct.safer_key*, !dbg !322
%key13 = getelementptr inbounds %struct.safer_key* %safer, i32 0, i32 0, !dbg !322
%arraydecay = getelementptr inbounds [217 x i8]* %key13, i32 0, i32 0, !dbg !322
call void @Safer_Expand_Userkey(i8* %6, i8* %7, i32 %cond.reload, i32 0, i8* %arraydecay), !dbg !322
store i32 0, i32* %retval, !dbg !323
br label %return, !dbg !323
are the same in the second file:
if.end11: ; preds = %loopEntry
%18 = load i8** %key.addr, align 8, !dbg !322
%19 = load i8** %key.addr, align 8, !dbg !322
...
cond.end: ; preds = %loopEntry
%cond.reload = load i32* %cond.reg2mem
%24 = load %union.Symmetric_key** %skey.addr, align 8, !dbg !322
%safer = bitcast %union.Symmetric_key* %24 to %struct.safer_key*, !dbg !322
%key13 = getelementptr inbounds %struct.safer_key* %safer, i32 0, i32 0, !dbg !322
%arraydecay = getelementptr inbounds [217 x i8]* %key13, i32 0, i32 0, !dbg !322
call void @Safer_Expand_Userkey(i8* %18, i8* %19, i32 %cond.reload, i32 0, i8* %arraydecay), !dbg !322
store i32 0, i32* %retval, !dbg !323
store i32 14, i32* %switchVar
br label %loopEnd
I don't understant why the first time I don't have a dominate problem, but the second time I do (I'm pretty sure it's because of the rest of my pass but I can't figure where because the code that cause problem it's the same in the both version).
Any idea?
Thx,
Cheers
safer.phi.ll (4.41 KB)
safer.phi.obfu.ll (5.87 KB)