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DLA: handle extractvalue from struct_initalizers

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This commit is contained in:
Pietro Fezzardi
2021-04-29 03:09:26 +02:00
parent 80b1a9e7fa
commit 49a493ebbb
3 changed files with 107 additions and 41 deletions
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lib/Decompiler/DLATypeSystem.cpp
+91 -30
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@@ -312,30 +312,59 @@ LayoutTypeSystem::getLayoutTypes(const Value &V) {
auto *RetTy = cast<StructType>(Callee->getReturnType());
revng_assert(RetTy->getNumElements() == Callee->arg_size());
revng_assert(Call->getNumUses() == 1
and isa<ReturnInst>(Call->uses().begin()->getUser()));
const Function *Caller = Call->getFunction();
Results = getLayoutTypes(*Caller);
revng_assert(Results.size() == Callee->arg_size());
bool OnlyReturnUses = true;
bool HasReturnUse = false;
for (const User *U : Call->users()) {
if (isa<ReturnInst>(U)) {
HasReturnUse = true;
const Function *Caller = Call->getFunction();
if (Results.empty())
Results = getLayoutTypes(*Caller);
else
revng_assert(Results == getLayoutTypes(*Caller));
revng_assert(Results.size() == Callee->arg_size());
} else {
OnlyReturnUses = false;
}
}
revng_assert(not HasReturnUse or OnlyReturnUses);
}
// If Results are full, we have detected a call to a struct_initializer
// that is returned, so we are done. Otherwise the have to look to for
// extractvalue instructions that are extracting values from the return
// value of the struct_initializer call.
if (Results.empty()) {
} else {
const auto ExtractedValues = getExtractedValuesFromCall(Call);
for (const auto &ExtractedSet : ExtractedValues) {
// Inside here we're working on a single field of the struct.
Results.resize(ExtractedValues.size(), {});
for (auto &Group : llvm::enumerate(ExtractedValues)) {
const auto &ExtractedSet = Group.value();
const auto FieldId = Group.index();
// Inside here we're working on a signle field of the struct.
// ExtractedSet contains all the ExtractValueInst that extract the
// same field of the struct.
// We get or create a layout type for each of them, but they should
// all be the same.
SmallVector<LayoutTypeSystemNode *, 2> FieldResults;
for (const llvm::ExtractValueInst *E : ExtractedSet) {
FieldResults.push_back(getLayoutType(E));
revng_assert(FieldResults.front() == FieldResults.back());
std::optional<LayoutTypeSystemNode *> FieldNode;
for (const llvm::ExtractValueInst *Ext : ExtractedSet) {
LayoutTypeSystemNode *ExtNode = getLayoutType(Ext);
if (FieldNode.has_value()) {
LayoutTypeSystemNode *Node = FieldNode.value();
revng_assert(not Node or not ExtNode or (Node == ExtNode));
if (not Node)
Node = ExtNode;
} else {
FieldNode = ExtNode;
}
}
Results.push_back(std::move(FieldResults.front()));
Results[FieldId] = FieldNode.value_or(nullptr);
}
}
@@ -391,30 +420,62 @@ LayoutTypeSystem::getOrCreateLayoutTypes(const Value &V) {
auto *RetTy = cast<StructType>(Callee->getReturnType());
revng_assert(RetTy->getNumElements() == Callee->arg_size());
revng_assert(Call->getNumUses() == 1
and isa<ReturnInst>(Call->uses().begin()->getUser()));
const Function *Caller = Call->getFunction();
Results = getOrCreateLayoutTypes(*Caller);
revng_assert(Results.size() == Callee->arg_size());
bool OnlyReturnUses = true;
bool HasReturnUse = false;
for (const User *U : Call->users()) {
if (isa<ReturnInst>(U)) {
HasReturnUse = true;
const Function *Caller = Call->getFunction();
if (Results.empty())
Results = getOrCreateLayoutTypes(*Caller);
else
revng_assert(Results == getOrCreateLayoutTypes(*Caller));
revng_assert(Results.size() == Callee->arg_size());
} else {
OnlyReturnUses = false;
}
}
revng_assert(not HasReturnUse or OnlyReturnUses);
}
// If Results are full, we have detected a call to a struct_initializer
// that is returned, so we are done. Otherwise the have to look to for
// extractvalue instructions that are extracting values from the return
// value of the struct_initializer call.
if (Results.empty()) {
} else {
const auto ExtractedValues = getExtractedValuesFromCall(Call);
for (const auto &ExtractedSet : ExtractedValues) {
// Inside here we're working on a single field of the struct.
Results.resize(ExtractedValues.size(), {});
for (auto &Group : llvm::enumerate(ExtractedValues)) {
const auto &ExtractedSet = Group.value();
const auto FieldId = Group.index();
// Inside here we're working on a signle field of the struct.
// ExtractedSet contains all the ExtractValueInst that extract the
// same field of the struct.
// We get or create a layout type for each of them, but they should
// all be the same.
SmallVector<GetOrCreateResult, 2> FldResults;
for (const llvm::ExtractValueInst *E : ExtractedSet) {
FldResults.push_back(getOrCreateLayoutType(E));
revng_assert(FldResults.front().first == FldResults.back().first);
std::optional<GetOrCreateResult> FieldResult;
for (const llvm::ExtractValueInst *Ext : ExtractedSet) {
GetOrCreateResult ExtResult = getOrCreateLayoutType(Ext);
if (FieldResult.has_value()) {
auto &[Node, New] = FieldResult.value();
const auto &[ExtNode, ExtNew] = ExtResult;
revng_assert(not ExtNew or ExtNode);
revng_assert(not Node or not ExtNode or (Node == ExtNode));
if (not Node)
Node = ExtNode;
New |= ExtNew;
} else {
FieldResult = ExtResult;
}
}
Results.push_back(std::move(FldResults.front()));
Results[FieldId] = FieldResult.value_or(GetOrCreateResult{});
}
}