Further reduce amount of memory allocations and leaks

Signed-off-by: Anton Korobeynikov <anton@korobeynikov.info>

frontends/p4/simplifyDefUse.cpp

@@ -168,31 +168,31 @@ class HeaderDefinitions : public IHasDbPrint {
  /// storage locations of all elements within the stack. In case of accessing
  /// a field of a header union within a stack (indexed with non-constant), it
  /// returns the corresponding field of all unions in the stack.
- const LocationSet *getStorageLocation(const IR::Expression *expression) const {
- LocationSet *result = new LocationSet;
+ LocationSet getStorageLocation(const IR::Expression *expression) const {
+ LocationSet result;
  if (auto expr = expression->to<IR::PathExpression>()) {
  auto decl = refMap->getDeclaration(expr->path, true);
- result->add(definitions->getStorage(decl));
+ result.add(definitions->getStorage(decl));
  } else if (auto expr = expression->to<IR::Member>()) {
  auto base_storage = getStorageLocation(expr->expr);
- for (auto bs : *base_storage) {
+ for (auto bs : base_storage) {
  if (auto struct_storage = bs->to<StructLocation>()) {
- struct_storage->addField(expr->member, result);
+ struct_storage->addField(expr->member, &result);
  } else if (bs->is<ArrayLocation>() && (expr->member == IR::Type_Stack::next ||
  expr->member == IR::Type_Stack::last ||
  expr->member == IR::Type_Stack::lastIndex)) {
  auto array_storage = bs->to<ArrayLocation>();
- for (auto element : *array_storage) result->add(element);
+ for (auto element : *array_storage) result.add(element);
  }
  }
  } else if (auto array = expression->to<IR::ArrayIndex>()) {
  auto base_storage = getStorageLocation(array->left);
- for (auto bs : *base_storage) {
+ for (auto bs : base_storage) {
  if (auto array_storage = bs->to<ArrayLocation>()) {
  if (auto index = array->right->to<IR::Constant>()) {
- array_storage->addElement(index->asInt(), result);
+ array_storage->addElement(index->asInt(), &result);
  } else {
- for (auto element : *array_storage) result->add(element);
+ for (auto element : *array_storage) result.add(element);
  }
  }
  }
@@ -248,9 +248,8 @@ class HeaderDefinitions : public IHasDbPrint {
  notReport.erase(storage);
  }
 
- void update(const LocationSet *locations, TernaryBool valid) {
- CHECK_NULL(locations);
- for (auto storage : *locations) {
+ void update(const LocationSet &locations, TernaryBool valid) {
+ for (const auto *storage : locations) {
  update(storage, valid);
  }
  }
@@ -275,13 +274,13 @@ class HeaderDefinitions : public IHasDbPrint {
  }
  } else { // constant index or accessing a field of a union which isn't in a stack
  // invalidate fields of a union
- auto base_storage = getStorageLocation(member->expr);
- for (auto bs : *base_storage) {
+ auto baseStorage = getStorageLocation(member->expr);
+ for (const auto *bs : baseStorage) {
  setValueToStorage(bs, TernaryBool::No);
  }
  // update valid bits of a field and a union
  update(getStorageLocation(expr), valid);
- update(base_storage, valid);
+ update(baseStorage, valid);
  }
  return;
  }
@@ -298,13 +297,11 @@ class HeaderDefinitions : public IHasDbPrint {
  }
 
  // result is OR operation on valid bits of all locations
- TernaryBool find(const LocationSet *locations) const {
- CHECK_NULL(locations);
-
- if (locations->isEmpty()) return TernaryBool::Yes;
+ TernaryBool find(const LocationSet &locations) const {
+ if (locations.isEmpty()) return TernaryBool::Yes;
 
  TernaryBool valid = TernaryBool::No;
- for (auto storage : *locations) {
+ for (const auto &storage : locations) {
  TernaryBool val = find(storage);
  if (val == TernaryBool::Maybe)
  valid = val;
@@ -339,9 +336,8 @@ class HeaderDefinitions : public IHasDbPrint {
  return result;
  }
 
- void addToNotReport(const LocationSet *locations) {
- CHECK_NULL(locations);
- for (auto storage : *locations) {
+ void addToNotReport(const LocationSet &locations) {
+ for (const auto *storage : locations) {
  checkLocation(storage);
  notReport.emplace(storage);
  if (auto header_union = storage->to<StructLocation>())
@@ -716,8 +712,7 @@ class FindUninitialized : public Inspector {
  processHeadersInAssignment(member, source->expression, ftype, sourceType);
  }
  } else if (src->is<IR::MethodCallExpression>()) {
- auto storage = headerDefs->getStorageLocation(dst);
- for (auto s : *storage) {
+ for (const auto *s : headerDefs->getStorageLocation(dst)) {
  headerDefs->setValueToStorage(s, TernaryBool::Yes);
  }
  } else if (src_type->to<IR::Type_Struct>()) {
@@ -739,8 +734,7 @@ class FindUninitialized : public Inspector {
  if (src->is<IR::InvalidHeaderUnion>()) {
  headerDefs->update(dst, TernaryBool::No);
  } else if (src->is<IR::MethodCallExpression>()) {
- auto storage = headerDefs->getStorageLocation(dst);
- for (auto s : *storage) {
+ for (auto s : headerDefs->getStorageLocation(dst)) {
  headerDefs->setValueToStorage(s, TernaryBool::Yes);
  }
  } else if (src_type->is<IR::Type_HeaderUnion>()) {
@@ -769,8 +763,7 @@ class FindUninitialized : public Inspector {
 
  if (auto st = dst_type->to<IR::Type_Stack>()) {
  if (src->is<IR::MethodCallExpression>()) {
- auto locations = headerDefs->getStorageLocation(dst);
- for (auto storage : *locations) {
+ for (const auto *storage : headerDefs->getStorageLocation(dst)) {
  headerDefs->setValueToStorage(storage, TernaryBool::Yes);
  }
  } else if (auto stack_exp = src->to<IR::HeaderStackExpression>()) {
@@ -785,9 +778,9 @@ class FindUninitialized : public Inspector {
  auto dst_locations = headerDefs->getStorageLocation(dst);
  auto src_locations = headerDefs->getStorageLocation(src);
 
- if (!dst_locations->isEmpty() && !src_locations->isEmpty()) {
- auto dst_storage = *dst_locations->begin();
- auto src_storage = *src_locations->begin();
+ if (!dst_locations.isEmpty() && !src_locations.isEmpty()) {
+ const auto *dst_storage = *dst_locations.begin();
+ const auto *src_storage = *src_locations.begin();
 
  auto dst_array_storage = dst_storage->to<ArrayLocation>();
  auto src_array_storage = src_storage->to<ArrayLocation>();
@@ -970,7 +963,7 @@ class FindUninitialized : public Inspector {
  lhs = true;
  visit(statement->decl, "decl");
  visit(statement->ref, "ref");
- for (auto *l : *headerDefs->getStorageLocation(statement->ref))
+ for (const auto *l : headerDefs->getStorageLocation(statement->ref))
  headerDefs->setValueToStorage(l, TernaryBool::Yes);
  lhs = false;
  currentPoint.assign(context, statement->ref);
@@ -1228,8 +1221,8 @@ class FindUninitialized : public Inspector {
  // Reads all array fields
  reads(expression, base);
  registerUses(expression, false);
- auto storage = headerDefs->getStorageLocation(bim->appliedTo);
- for (auto s : *storage) headerDefs->setValueToStorage(s, TernaryBool::Yes);
+ for (const auto *s : headerDefs->getStorageLocation(bim->appliedTo))
+   headerDefs->setValueToStorage(s, TernaryBool::Yes);
  return false;
  } else if (name == IR::Type_Header::isValid) {
  auto storage = base->getField(StorageFactory::validFieldName);
@@ -1331,8 +1324,8 @@ class FindUninitialized : public Inspector {
  if (typeMap->getType(expr->expression, true)->is<IR::Type_Header>()) {
  headerDefs->update(expr->expression, TernaryBool::Yes);
  } else {
- auto locations = headerDefs->getStorageLocation(expr->expression);
- for (auto storage : *locations) {
+ for (const auto *storage :
+  headerDefs->getStorageLocation(expr->expression)) {
  headerDefs->setValueToStorage(storage, TernaryBool::Yes);
  }
  }