mirror of
https://github.com/revng/revng
synced 2026-06-21 14:07:57 +00:00
Alessandro Di Federico
f68b7866b3
This commit introduces `BasicBlockID` as the unique identifier for a `efa::BasicBlock` into the CFG. A `BasicBlockID` is defined by a `MetaAddress` plus an incremental integer. This enables us to have multiple instances of the same block in a single function, which is particularly useful when inlining multiple times the same function. Apart from this, the commit also does the following: * It drops representing `MetaAddress`es a `structs` in the IR. This created several issues related to ABI. We now represent them as strings. * It defines more functions in `support.h`, instead of defining prototypes by hand in `CodeGenerator.cpp` and the like. Specifically, `unknownPC` and `raise_exception_helper`. We also introduce a C "constructor" for `PlainMetaAddress`. * It significantly reduces the API of `GeneratedCodeBasicInfo`, which was supposed to be put on a diet since a long time. Specifically, many jump target related methods have been moved to free functions in `IRHelpers.h`. Also `GCBI::getSuccessors` has been pushed into its only user, `PruneRetSuccessors`, to prevent further usage of a deprecated API. In the future, it would be nice to drop it entirely. * It introduces `efa::BasicBlock::InlinedFrom`. * Introduce an enum to represent named argument indices for `newpc`. This enables us to more effectively manipulate its argument list. * It improves the verification and error reporting for `efa::FunctionMetadata`. * Update tests. This commit is preliminary to another piece of work to improve the generality of inlining beyond the simple "fake function" scenario, for which the feature was originally conceived.
118 lines
3.1 KiB
C++
118 lines
3.1 KiB
C++
/// \file CollectCFG.cpp
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//
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// This file is distributed under the MIT License. See LICENSE.md for details.
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//
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#include "revng/BasicAnalyses/GeneratedCodeBasicInfo.h"
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#include "revng/EarlyFunctionAnalysis/CFGAnalyzer.h"
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#include "revng/EarlyFunctionAnalysis/CollectCFG.h"
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#include "revng/EarlyFunctionAnalysis/FunctionMetadata.h"
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#include "revng/Model/Binary.h"
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using namespace llvm;
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namespace efa {
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class CollectCFG {
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private:
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llvm::Module &M;
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GeneratedCodeBasicInfo &GCBI;
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const TupleTree<model::Binary> &Binary;
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CFGAnalyzer &Analyzer;
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public:
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CollectCFG(llvm::Module &M,
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GeneratedCodeBasicInfo &GCBI,
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const TupleTree<model::Binary> &Binary,
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CFGAnalyzer &Analyzer) :
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M(M), GCBI(GCBI), Binary(Binary), Analyzer(Analyzer) {}
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public:
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void run() {
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auto Result = recoverCFGs();
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serializeFunctionMetadata(Result);
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}
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private:
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std::vector<efa::FunctionMetadata> recoverCFGs();
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void
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serializeFunctionMetadata(const std::vector<efa::FunctionMetadata> &CFGs);
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};
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using CFGVector = vector<FunctionMetadata>;
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void CollectCFG::serializeFunctionMetadata(const CFGVector &CFGs) {
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using namespace llvm;
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using llvm::BasicBlock;
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LLVMContext &Context = M.getContext();
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for (const efa::FunctionMetadata &FM : CFGs) {
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FM.verify(*Binary, true);
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BasicBlock *BB = GCBI.getBlockAt(FM.Entry());
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std::string Buffer;
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{
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raw_string_ostream Stream(Buffer);
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serialize(Stream, FM);
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}
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Instruction *Term = BB->getTerminator();
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MDNode *Node = MDNode::get(Context, MDString::get(Context, Buffer));
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Term->setMetadata(FunctionMetadataMDName, Node);
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}
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}
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std::vector<efa::FunctionMetadata> CollectCFG::recoverCFGs() {
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std::vector<efa::FunctionMetadata> Result;
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for (const auto &Function : Binary->Functions()) {
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auto *Entry = GCBI.getBlockAt(Function.Entry());
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revng_assert(Entry != nullptr);
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// Recover the control-flow graph of the function
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efa::FunctionMetadata New;
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New.Entry() = Function.Entry();
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New.ControlFlowGraph() = std::move(Analyzer.analyze(Entry).CFG);
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revng_assert(New.ControlFlowGraph().count(BasicBlockID(New.Entry())) != 0);
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// Run final steps on the CFG
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New.simplify(*Binary);
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revng_assert(New.ControlFlowGraph().count(BasicBlockID(New.Entry())) != 0);
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Result.emplace_back(std::move(New));
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}
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return Result;
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}
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bool CollectCFGPass::runOnModule(Module &M) {
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revng_log(PassesLog, "Starting EarlyFunctionAnalysis");
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if (not M.getFunction("root") or M.getFunction("root")->isDeclaration())
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return false;
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auto &GCBI = getAnalysis<GeneratedCodeBasicInfoWrapperPass>().getGCBI();
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auto &LMP = getAnalysis<LoadModelWrapperPass>().get();
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const TupleTree<model::Binary> &Binary = LMP.getReadOnlyModel();
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FunctionSummaryOracle Oracle;
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importModel(M, GCBI, *Binary, Oracle);
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CFGAnalyzer Analyzer(M, GCBI, Binary, Oracle);
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CollectCFG CFGCollector(M, GCBI, Binary, Analyzer);
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CFGCollector.run();
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return false;
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}
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char CollectCFGPass::ID = 0;
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using CFGCollectionPass = RegisterPass<CollectCFGPass>;
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static CFGCollectionPass X("collect-cfg", "CFG Collection Pass", true, true);
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} // namespace efa
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