Remove NoExitRuntime pass (#4431)

After emscripten-core/emscripten#15905 lands Emscripten will no longer use it,
and nothing else needs it AFAIK.

1 files changed, 0 insertions, 65 deletions

diff --git a/src/passes/NoExitRuntime.cpp b/src/passes/NoExitRuntime.cpp
deleted file mode 100644
index e15ef81bc..000000000
--- a/src/passes/NoExitRuntime.cpp
+++ /dev/null
@@ -1,65 +0,0 @@
-/*
- * Copyright 2016 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.
- */
-
-//
-// Assumes the program will never exit the runtime (as in the emscripten
-// NO_EXIT_RUNTIME option). That means that atexit()s do not need to be
-// run.
-//
-
-#include <asmjs/shared-constants.h>
-#include <pass.h>
-#include <wasm-builder.h>
-#include <wasm.h>
-
-namespace wasm {
-
-struct NoExitRuntime : public WalkerPass<PostWalker<NoExitRuntime>> {
-  bool isFunctionParallel() override { return true; }
-
-  Pass* create() override { return new NoExitRuntime; }
-
-  // Remove all possible manifestations of atexit, across llvm wasm
-  // backend.
-  std::array<Name, 4> ATEXIT_NAMES = {
-    {"___cxa_atexit", "__cxa_atexit", "_atexit", "atexit"}};
-
-  void visitCall(Call* curr) {
-    auto* import = getModule()->getFunctionOrNull(curr->target);
-    if (!import || !import->imported() || import->module != ENV) {
-      return;
-    }
-    for (auto name : ATEXIT_NAMES) {
-      if (name == import->base) {
-        // Remove the call, and drop the arguments (which may have side
-        // effects); let other passes clean that up more.
-        Builder builder(*getModule());
-        std::vector<Expression*> args;
-        for (auto* operand : curr->operands) {
-          args.push_back(builder.makeDrop(operand));
-        }
-        // Ensure the block has the right type using the last arg.
-        args.push_back(builder.replaceWithIdenticalType(curr));
-        replaceCurrent(builder.makeBlock(args));
-        break;
-      }
-    }
-  }
-};
-
-Pass* createNoExitRuntimePass() { return new NoExitRuntime(); }
-
-} // namespace wasm