[NFC] Rename the old topological sort utility (#6914)

This will allow both the old and new topological sort utilities to be
included into the same .cpp file while we phase out the old utility.

1 files changed, 0 insertions, 118 deletions

diff --git a/src/support/topological_sort.h b/src/support/topological_sort.h
deleted file mode 100644
index 3594617eb..000000000
--- a/src/support/topological_sort.h
+++ /dev/null
@@ -1,118 +0,0 @@
-/*
- * Copyright 2022 WebAssembly Community Group participants
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef wasm_support_topological_sort_h
-#define wasm_support_topological_sort_h
-
-#include <cstddef>
-#include <iterator>
-#include <unordered_set>
-#include <vector>
-
-namespace wasm {
-
-// CRTP utility that provides an iterator through arbitrary directed acyclic
-// graphs of data that will visit the data in a topologically sorted order
-// (https://en.wikipedia.org/wiki/Topological_sorting). In other words, the
-// iterator will produce each item only after all that item's predecessors have
-// been produced.
-//
-// Subclasses should call `push` on all the root items in their constructors and
-// implement a `void pushPredecessors(T item)` method that calls `push` on all
-// the immediate predecessors of `item`.
-//
-// Cycles in the graph are not detected and will result in an infinite loop.
-template<typename T, typename Subtype> struct TopologicalSort {
-private:
-  // The DFS work list.
-  std::vector<T> workStack;
-
-  // Remember which items we have finished so we don't visit them again.
-  std::unordered_set<T> finished;
-
-  // Should be overridden by `Subtype`.
-  void pushPredecessors(T item) {
-    static_assert(&TopologicalSort<T, Subtype>::pushPredecessors !=
-                    &Subtype::pushPredecessors,
-                  "TopologicalSort subclass must implement `pushPredecessors`");
-  }
-
-  // Pop until the stack is empty or it has an unfinished item on top.
-  void finishCurr() {
-    finished.insert(workStack.back());
-    workStack.pop_back();
-    while (!workStack.empty() && finished.count(workStack.back())) {
-      workStack.pop_back();
-    }
-  }
-
-  // Advance until the next item to be finished is on top of the stack or the
-  // stack is empty.
-  void stepToNext() {
-    while (!workStack.empty()) {
-      T item = workStack.back();
-      static_cast<Subtype*>(this)->pushPredecessors(item);
-      if (workStack.back() == item) {
-        // No unfinished predecessors, so this is the next item in the sort.
-        break;
-      }
-    }
-  }
-
-protected:
-  // Call this from the `Subtype` constructor to add the root items and from
-  // `Subtype::pushPredecessors` to add predecessors.
-  void push(T item) {
-    if (finished.count(item)) {
-      return;
-    }
-    workStack.push_back(item);
-  }
-
-public:
-  struct Iterator {
-    using value_type = T;
-    using difference_type = std::ptrdiff_t;
-    using reference = T&;
-    using pointer = T*;
-    using iterator_category = std::input_iterator_tag;
-
-    TopologicalSort<T, Subtype>* parent;
-
-    bool isEnd() const { return !parent || parent->workStack.empty(); }
-    bool operator==(Iterator& other) const { return isEnd() == other.isEnd(); }
-    bool operator!=(Iterator& other) const { return !(*this == other); }
-    T operator*() { return parent->workStack.back(); }
-    void operator++(int) {
-      parent->finishCurr();
-      parent->stepToNext();
-    }
-    Iterator& operator++() {
-      (*this)++;
-      return *this;
-    }
-  };
-
-  Iterator begin() {
-    stepToNext();
-    return {this};
-  }
-  Iterator end() { return {nullptr}; }
-};
-
-} // namespace wasm
-
-#endif // wasm_support_topological_sort_h