1 /* 2 * Copyright 2016 WebAssembly Community Group participants 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 // Removes code from all functions but one, leaving a valid module 18 // with (mostly) just the code you want to debug (function-parallel, 19 // non-lto) passes on. 20 21 #include "pass.h" 22 #include "wasm.h" 23 24 namespace wasm { 25 26 struct ExtractFunction : public Pass { runwasm::ExtractFunction27 void run(PassRunner* runner, Module* module) override { 28 Name name = runner->options.getArgument( 29 "extract", 30 "ExtractFunction usage: wasm-opt --pass-arg=extract@FUNCTION_NAME"); 31 std::cerr << "extracting " << name << "\n"; 32 bool found = false; 33 for (auto& func : module->functions) { 34 if (func->name != name) { 35 // Turn it into an import. 36 func->module = "env"; 37 func->base = func->name; 38 func->vars.clear(); 39 func->body = nullptr; 40 } else { 41 found = true; 42 } 43 } 44 if (!found) { 45 Fatal() << "could not find the function to extract\n"; 46 } 47 // clear data 48 module->memory.segments.clear(); 49 module->table.segments.clear(); 50 // leave just an export for the thing we want 51 if (!module->getExportOrNull(name)) { 52 module->exports.clear(); 53 auto* export_ = new Export; 54 export_->name = name; 55 export_->value = name; 56 export_->kind = ExternalKind::Function; 57 module->addExport(export_); 58 } 59 } 60 }; 61 62 // declare pass 63 createExtractFunctionPass()64Pass* createExtractFunctionPass() { return new ExtractFunction(); } 65 66 } // namespace wasm 67