From 370dc79ad6da88b8548d9ebd52601271bf279213 Mon Sep 17 00:00:00 2001 From: Christoph Egger Date: Tue, 3 Jun 2014 15:24:57 +0200 Subject: [PATCH] Split BasicBlocks if there are backward jumps --- src/disassembler/llvm/LLVMDisassembler.cxx | 36 ++++++++++++++++++++-- 1 file changed, 33 insertions(+), 3 deletions(-) diff --git a/src/disassembler/llvm/LLVMDisassembler.cxx b/src/disassembler/llvm/LLVMDisassembler.cxx index a194d21..25a4ecc 100644 --- a/src/disassembler/llvm/LLVMDisassembler.cxx +++ b/src/disassembler/llvm/LLVMDisassembler.cxx @@ -121,9 +121,6 @@ LLVMDisassembler::~LLVMDisassembler() { }); } -/* - * TODO: If we jump into some Basic Block we need to split it there into two - */ void LLVMDisassembler::disassemble() { std::stack remaining_functions; std::stack remaining_blocks; @@ -245,6 +242,39 @@ void LLVMDisassembler::disassemble() { } LOG4CXX_DEBUG(logger, "Finished function " << current_function->getName()); } + + // Split blocks where jumps are going inside the block + for (auto it = blocks.begin(); it != blocks.end(); ++it) { + LLVMBasicBlock * current_block = it->second; + uint64_t inst_size; + uint64_t base_address; + text_section.getAddress(base_address); + uint64_t current_address = current_block->getStartAddress() - base_address; + while(current_block->getEndAddress() - base_address != current_address) { + MCInst inst; + std::string buf; + llvm::raw_string_ostream s(buf); + + if(llvm::MCDisassembler::Success == + DisAsm->getInstruction(inst, inst_size, ref, current_address, nulls(), nulls())) { + auto other = blocks.find(current_address + inst_size + base_address); + + if (other != blocks.end()) { + LOG4CXX_DEBUG(logger, "Shortening block starting at " + << std::hex + << current_block->getStartAddress() + << " now ending at " + << other->first); + current_block->setEndAddress(current_address + inst_size + base_address); + current_block->setNextBlock(0, other->first); + current_block->setNextBlock(1, 0); + } + } else { + inst_size = 1; + } + current_address += inst_size; + } + } } void LLVMDisassembler::readSymbols() { -- 2.39.5