Remove support for emscripten legacy PIC ABI (#3299)

1 files changed, 0 insertions, 142 deletions

diff --git a/src/passes/EmscriptenPIC.cpp b/src/passes/EmscriptenPIC.cpp
deleted file mode 100644
index 51f7ead6e..000000000
--- a/src/passes/EmscriptenPIC.cpp
+++ /dev/null
@@ -1,142 +0,0 @@
-/*
- * Copyright 2020 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.
- */
-
-//
-// Convert LLVM PIC ABI to emscripten ABI
-//
-// When generating -fPIC code llvm will generate imports call GOT.mem and
-// GOT.func in order to access the addresses of external global data and
-// functions.
-//
-// However emscripten uses a different ABI where function and data addresses
-// are available at runtime via special `g$foo` and `fp$bar` function calls.
-//
-// Here we internalize all such wasm globals and generte code that sets their
-// value based on the result of call `g$foo` and `fp$bar` functions at runtime.
-//
-// A function called `__assign_got_enties` is generated by this pass that
-// performs all the assignments.
-//
-
-#include "abi/js.h"
-#include "asm_v_wasm.h"
-#include "ir/import-utils.h"
-#include "ir/table-utils.h"
-#include "pass.h"
-#include "shared-constants.h"
-#include "support/debug.h"
-
-#define DEBUG_TYPE "emscripten-pic"
-
-namespace wasm {
-
-static Function*
-ensureFunctionImport(Module* module, Name name, Signature sig) {
-  // See if its already imported.
-  // FIXME: O(N)
-  ImportInfo info(*module);
-  if (auto* f = info.getImportedFunction(ENV, name)) {
-    return f;
-  }
-  // Failing that create a new import.
-  auto import = new Function;
-  import->name = name;
-  import->module = ENV;
-  import->base = name;
-  import->sig = sig;
-  module->addFunction(import);
-  return import;
-}
-
-struct EmscriptenPIC : public WalkerPass<PostWalker<EmscriptenPIC>> {
-
-  EmscriptenPIC(bool sideModule) : sideModule(sideModule) {}
-
-  void visitGlobal(Global* curr) {
-    if (!curr->imported()) {
-      return;
-    }
-    if (curr->module == "GOT.func") {
-      gotFuncEntries.push_back(curr);
-    } else if (curr->module == "GOT.mem") {
-      gotMemEntries.push_back(curr);
-    } else {
-      return;
-    }
-    // Make this an internal, non-imported, global.
-    curr->module.clear();
-    curr->init = Builder(*getModule()).makeConst(int32_t(0));
-  }
-
-  void visitModule(Module* module) {
-    BYN_TRACE("generateAssignGOTEntriesFunction\n");
-    if (!gotFuncEntries.size() && !gotMemEntries.size()) {
-      return;
-    }
-
-    Builder builder(*getModule());
-    Function* assignFunc = builder.makeFunction(
-      ASSIGN_GOT_ENTRIES, std::vector<NameType>{}, Type::none, {});
-    Block* block = builder.makeBlock();
-    assignFunc->body = block;
-
-    for (Global* g : gotMemEntries) {
-      auto base = g->base;
-      Name getter(std::string("g$") + base.c_str());
-      ensureFunctionImport(module, getter, Signature(Type::none, Type::i32));
-      Expression* call = builder.makeCall(getter, {}, Type::i32);
-      GlobalSet* globalSet = builder.makeGlobalSet(g->name, call);
-      block->list.push_back(globalSet);
-    }
-
-    ImportInfo importInfo(*module);
-
-    for (Global* g : gotFuncEntries) {
-      // The function has to exist either as export or an import.
-      // Note that we don't search for the function by name since its internal
-      // name may be different.
-      auto* ex = module->getExportOrNull(g->base);
-      // This is imported create an fp$ import to get the function table index
-      // from the dynamic loader.
-      auto* f = importInfo.getImportedFunction(ENV, g->base);
-      if (!f) {
-        if (!module->getExportOrNull(g->base)) {
-          Fatal() << "GOT.func entry with no import/export: " << g->base;
-        }
-        f = module->getFunction(ex->value);
-      }
-      Name getter(
-        (std::string("fp$") + g->base.c_str() + std::string("$") + getSig(f))
-          .c_str());
-      ensureFunctionImport(module, getter, Signature(Type::none, Type::i32));
-      auto* call = builder.makeCall(getter, {}, Type::i32);
-      auto* globalSet = builder.makeGlobalSet(g->name, call);
-      block->list.push_back(globalSet);
-    }
-
-    module->addFunction(assignFunc);
-  }
-
-  std::vector<Global*> gotFuncEntries;
-  std::vector<Global*> gotMemEntries;
-  bool sideModule;
-};
-
-Pass* createEmscriptenPICPass() { return new EmscriptenPIC(true); }
-
-Pass* createEmscriptenPICMainModulePass() { return new EmscriptenPIC(false); }
-
-} // namespace wasm