int
main(int argc, char *argv[]) {
std::string purpose = "tests StaticSemantics";
std::string description =
"ROSE has two forms of instruction semantics. The most general is that which is part of the Semantics2 API "
"and which provides semantic lookup tables, arbitrary domains, and virtual machine states. But users coming "
"from other platforms might be more accustomed to having semantics represented statically as part of an "
"abstract syntax tree. ROSE can build these static semantics ASTs from its StaticSemantics domain in the "
"Semantics2 API, and that is what this program tests.";
P2::Engine engine;
SgAsmBlock *gblock = engine.frontend(argc, argv, purpose, description);
InstructionSemantics2::StaticSemantics::attachInstructionSemantics(gblock, engine.disassembler());
#if 1 // DEBUGGING [Robb P. Matzke 2015-06-08]
generateDOT(*SageInterface::getProject());
#endif
}
int
main(int argc, char *argv[]) {
// This paragraph initializes the ROSE library, generates the man page for this tool, does command-line parsing for quite a
// few switches including "--help", loads various specimen resources (ELF/PE, running process, raw memory dumps, etc),
// disassembles, and partitions. We could have called Engine::frontend() and done it all in one function call, but then we
// wouldn't have a Partitioner2::Partitioner object that we need below.
std::string purpose = "demonstrate inter-function disassembly";
std::string description =
"Disassembles and partitions the specimen(s), then tries to disassemble things between the functions.";
P2::Engine engine;
std::vector<std::string> specimens = engine.parseCommandLine(argc, argv, purpose, description).unreachedArgs();
P2::Partitioner partitioner = engine.partition(specimens);
// The partitioner's address usage map (AUM) describes what part of memory has been disassembled as instructions or
// data. We're interested in the unused parts between the lowest and highest disassembled addresses, so we loop over those
// parts. The hull() is the entire used interval -- lowest to highest addresses used regardless of the unused areas in the
// middle. An AddressInterval evaluated in boolean context returns false if it's empty.
rose_addr_t va = partitioner.aum().hull().least();
while (AddressInterval unused = partitioner.aum().nextUnused(va)) {
// Is the unused area beyond the last thing compiled? We're only interested in the stuff between functions. This
// check also means that unused.greatest()+1 will not overflow, which simplifies later code. Overflows are easy to
// trigger when the specimen's word size is the same as ROSE's word size.
if (unused.least() > partitioner.aum().hull().greatest())
break;
// The unused address might be in the middle of some very large unmapped area of memory, or perhaps in an area that
// doesn't have execute permission (the partitioner will only disassemble at addresses that we've marked as
// executable). A naive implementation would just increment to the next address and try again, but that could take a
// very long time. This "if" statement will give us the next executable address that falls within the unused interval
// if possible. The address is assigned to "va" if possible.
if (!engine.memoryMap().within(unused).require(MemoryMap::EXECUTABLE).next().assignTo(va)) {
va = unused.greatest() + 1; // won't overflow because of check above
continue;
}
// "va" now points to an executable address that the partitioner doesn't know about yet.
ASSERT_require(engine.memoryMap().at(va).require(MemoryMap::EXECUTABLE).exists());
ASSERT_forbid(partitioner.aum().instructionExists(va));
std::cout <<"unused address " <<StringUtility::addrToString(va) <<"\n";
// Cause the partitioner to discover (disassemble) one basic block. This doesn't add the basic block to the
// partitioner or change the partitioner in any way. If the BB isn't something we want to keep then just forget about
// it and garbage collection will reclaim the memory.
P2::BasicBlock::Ptr bb = partitioner.discoverBasicBlock(va);
if (!isGoodBasicBlock(bb)) {
++va;
continue;
}
std::cout <<" disassembled " <<bb->printableName() <<"\n";
// Inform the partitioner that we wish to keep this BB.
partitioner.attachBasicBlock(bb);
// This BB was not reachable by any previous CFG edge, therefore it doesn't belong to any function. In order for it to
// show up in the eventual AST we need to add it to some function (the ROSE AST has a requirement that every basic
// block belongs to a function, although the partitioner can easily cope with the other case). The easiest way in this
// situation is to just create a new function whose entry block is this BB. Creating a function doesn't modify the
// partitioner in any way, so we need to also attach the function to the partitioner.
P2::Function::Ptr function = P2::Function::instance(va, SgAsmFunction::FUNC_USERDEF);
function->insertBasicBlock(va); // allowed only before attaching function to partitioner
partitioner.attachOrMergeFunction(function);
// This basic block might be the first block of a whole bunch that are connected by as yet undiscovered CFG edges. We
// can recursively discover and attach all those blocks with one Engine method. There are also Partitioner methods to
// do similar things, but they're lower level.
engine.runPartitionerRecursive(partitioner);
}
// We've probably added a bunch more functions and basic blocks to the partitioner, but we haven't yet assigned the basic
// blocks discovered by Engine::runPartitionerRecursive to any functions. We might also need to assign function labels
// from ELF/PE information, re-run some analysis, etc., so do that now.
engine.runPartitionerFinal(partitioner);
// Most ROSE analysis is performed on an abstract syntax tree, so generate one. If the specime is an ELF or PE container
// then the returned global block will also be attached somewhere below a SgProject node, otherwise the returned global
// block is the root of the AST and there is no project (e.g., like when the specimen is a raw memory dump).
SgAsmBlock *gblock = P2::Modules::buildAst(partitioner, engine.interpretation());
// Generate an assembly listing. These unparser properties are all optional, but they result in more informative assembly
// listings.
AsmUnparser unparser;
unparser.set_registers(partitioner.instructionProvider().registerDictionary());
unparser.add_control_flow_graph(ControlFlow().build_block_cfg_from_ast<ControlFlow::BlockGraph>(gblock));
unparser.staticDataDisassembler.init(engine.disassembler());
unparser.unparse(std::cout, gblock);
}
