lib/base-compiler.js - compiler-explorer - Rivoreo Source Code Repositories

 // Copyright (c) 2012-2017, Matt Godbolt
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are met:
 //
 //     * Redistributions of source code must retain the above copyright notice,
 //       this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above copyright
 //       notice, this list of conditions and the following disclaimer in the
 //       documentation and/or other materials provided with the distribution.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 // ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 // LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 // CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 // SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 // CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 // POSSIBILITY OF SUCH DAMAGE.

 var child_process = require('child_process'),
     temp = require('temp'),
     path = require('path'),
     fs = require('fs-extra'),
     Promise = require('promise'), // jshint ignore:line
     asm = require('./asm'),
     utils = require('./utils'),
     quote = require('shell-quote'),
     _ = require('underscore-node'),
     exec = require('./exec'),
     logger = require('./logger').logger,
     compilerOptInfo = require("compiler-opt-info");

 function Compile(compiler, env) {
     this.compiler = compiler;
     this.env = env;
     this.asm = new asm.AsmParser(env.compilerProps);
     this.compiler.supportsIntel = !!this.compiler.intelAsm;
 }

 Compile.prototype.newTempDir = function () {
     return new Promise(function (resolve, reject) {
         temp.mkdir('compiler-explorer-compiler', function (err, dirPath) {
             if (err)
                 reject("Unable to open temp file: " + err);
             else
                 resolve(dirPath);
         });
     });
 };

 Compile.prototype.writeFile = Promise.denodeify(fs.writeFile);
 Compile.prototype.readFile = Promise.denodeify(fs.readFile);
 Compile.prototype.stat = Promise.denodeify(fs.stat);
 Compile.prototype.couldHaveOptOutput = function (options, version) {
     //TODO(jared): a compiler meta data gatherer could improve this
     return version.toLowerCase().indexOf("clang") > -1 &&
         options.some((x) => x == "-fsave-optimization-record");
 };

 Compile.prototype.getRemote = function () {
     if (this.compiler.exe === null && this.compiler.remote)
         return this.compiler.remote;
     return false;
 };

 Compile.prototype.exec = function (compiler, args, options) {
     // Here only so can be overridden by compiler implementations.
     return exec.execute(compiler, args, options);
 };

 Compile.prototype.runCompiler = function (compiler, options, inputFilename) {
     return this.exec(compiler, options, {
         timeoutMs: this.env.gccProps("compileTimeoutMs", 100),
         maxErrorOutput: this.env.gccProps("max-error-output", 5000),
         env: this.env.getEnv(this.compiler.needsMulti),
         wrapper: this.env.compilerProps("compiler-wrapper")
     }).then(function (result) {
         result.stdout = utils.parseOutput(result.stdout, inputFilename);
         result.stderr = utils.parseOutput(result.stderr, inputFilename);
         return result;
     });
 };

 Compile.prototype.supportsObjdump = function () {
     return this.compiler.objdumper !== "";
 };

 Compile.prototype.objdump = function (outputFilename, result, maxSize, intelAsm) {
     var args = ["-d", "-C", outputFilename, "-l", "--insn-width=16"];
     if (intelAsm) args = args.concat(["-M", "intel"]);
     return this.exec(this.compiler.objdumper, args, {maxOutput: maxSize})
         .then(function (objResult) {
             result.asm = objResult.stdout;
             if (objResult.code !== 0) {
                 result.asm = "<No output: objdump returned " + objResult.code + ">";
             }
             return result;
         });
 };

 Compile.prototype.execBinary = function (executable, result, maxSize) {
     return exec.sandbox(executable, [], {maxOutput: maxSize, timeoutMs: 2000})  // TODO make config
         .then(function (execResult) {
             execResult.stdout = utils.parseOutput(execResult.stdout);
             execResult.stderr = utils.parseOutput(execResult.stderr);
             result.execResult = execResult;
             return result;
         }).catch(function (err) {
             // TODO: is this the best way? Perhaps failures in sandbox shouldn't reject
             // with "results", but instead should play on?
             result.execResult = {
                 stdout: err.stdout ? utils.parseOutput(err.stdout) : [],
                 stderr: err.stderr ? utils.parseOutput(err.stderr) : [],
                 code: err.code !== undefined ? err.code : -1
             };
             return result;
         });
 };

 Compile.prototype.filename = function (fn) {
     return fn;
 };

 Compile.prototype.optionsForFilter = function (filters, outputFilename) {
     var options = ['-g', '-o', this.filename(outputFilename)];
     if (this.compiler.intelAsm && filters.intel && !filters.binary) {
         options = options.concat(this.compiler.intelAsm.split(" "));
     }
     if (!filters.binary) options = options.concat('-S');
     return options;
 };

 Compile.prototype.prepareArguments = function (userOptions, filters, inputFilename, outputFilename) {
     var options = this.optionsForFilter(filters, outputFilename);
     if (this.compiler.options) {
         options = options.concat(this.compiler.options.split(" "));
     }
     return options.concat(userOptions || []).concat([this.filename(inputFilename)]);
 };

 Compile.prototype.compile = function (source, options, filters) {
     var self = this;
     var optionsError = self.checkOptions(options);
     if (optionsError) return Promise.reject(optionsError);
     var sourceError = self.checkSource(source);
     if (sourceError) return Promise.reject(sourceError);

     // Don't run binary for unsupported compilers, even if we're asked.
     if (filters.binary && !self.compiler.supportsBinary) {
         delete filters.binary;
     }

     var key = JSON.stringify({compiler: this.compiler, source: source, options: options, filters: filters});
     var cached = this.env.cacheGet(key);
     if (cached) {
         return Promise.resolve(cached);
     }

     if (filters.binary && !source.match(this.env.compilerProps("stubRe"))) {
         source += "\n" + this.env.compilerProps("stubText") + "\n";
     }
     return self.env.enqueue(function () {
         var tempFileAndDirPromise = Promise.resolve().then(function () {
             return self.newTempDir().then(function (dirPath) {
                 var inputFilename = path.join(dirPath, self.env.compilerProps("compileFilename"));
                 return self.writeFile(inputFilename, source).then(function () {
                     return {inputFilename: inputFilename, dirPath: dirPath};
                 });
             });
         });

         var compileToAsmPromise = tempFileAndDirPromise.then(function (info) {
             var inputFilename = info.inputFilename;
             var dirPath = info.dirPath;
             var outputFilebase = "output";
             var outputFilename = path.join(dirPath, outputFilebase + ".s"); // NB keep lower case as ldc compiler `tolower`s the output name
             options = self.prepareArguments(options, filters, inputFilename, outputFilename);

             options = options.filter(_.identity);
             return self.runCompiler(self.compiler.exe, options, self.filename(inputFilename))
                 .then(function (result) {
                     result.dirPath = dirPath;
                     if (result.code !== 0) {
                         result.asm = "<Compilation failed>";
                         return result;
                     }
                     result.hasOptOutput = false;
                     if (self.couldHaveOptOutput(options, self.compiler.version)) {
                         const optPath = path.join(dirPath, outputFilebase + ".opt.yaml");
                         if (fs.existsSync(optPath)) {
                             result.hasOptOutput = true;
                             result.optPath = optPath;
                         }
                     }
                     return self.postProcess(result, outputFilename, filters);
                 });
         });

         return compileToAsmPromise
             .then(function (results) {
                 //TODO(jared): this isn't ideal. Rethink
                 var result;
                 var optOutput;
                 if (results.length) {
                     result = results[0];
                     optOutput = results[1];
                 } else {
                     result = results;
                 }
                 if (result.dirPath) {
                     fs.remove(result.dirPath);
                     result.dirPath = undefined;
                 }
                 if (result.okToCache) {
                     result.asm = self.asm.process(result.asm, filters);
                 } else {
                     result.asm = {text: result.asm};
                 }
                 if (result.hasOptOutput) {
                     result.optPath = undefined;
                     result.optOutput = optOutput;
                 }
                 return result;
             })
             .then(_.bind(self.postProcessAsm, self))
             .then(function (result) {
                 if (result.okToCache) self.env.cachePut(key, result);
                 return result;
             });
     });
 };

 Compile.prototype.postProcessAsm = function (result) {
     if (!result.okToCache) return result;
     var demangler = this.compiler.demangler;
     if (!demangler) return result;
     return this.exec(demangler, [], {input: _.pluck(result.asm, 'text').join("\n")})
         .then(function (demangleResult) {
             var lines = utils.splitLines(demangleResult.stdout);
             for (var i = 0; i < result.asm.length; ++i)
                 result.asm[i].text = lines[i];
             return result;
         });
 };

 Compile.prototype.processOptOutput = function (hasOptOutput, optPath) {
     var output = [];
     return new Promise(
         function (resolve, reject) {
             fs.createReadStream(optPath, {encoding: "utf-8"})
                 .pipe(new compilerOptInfo.LLVMOptTransformer())
                 .on("data", function (opt) {
                     output.push(opt);
                 })
                 .on("end", function () {
                     resolve(output);
                 });
         });
 };


 Compile.prototype.postProcess = function (result, outputFilename, filters) {
     var postProcess = this.compiler.postProcess.filter(_.identity);
     var maxSize = this.env.gccProps("max-asm-size", 8 * 1024 * 1024);
     var optPromise, asmPromise, execPromise;
     if (result.hasOptOutput) {
         optPromise = this.processOptOutput(result.hasOptOutput, result.optPath);
     } else {
         optPromise = Promise.resolve("");
     }
     if (filters.binary && this.supportsObjdump()) {
         asmPromise = this.objdump(outputFilename, result, maxSize, filters.intel);
     } else {
         asmPromise = this.stat(outputFilename).then(_.bind(function (stat) {
                 if (stat.size >= maxSize) {
                     result.asm = "<No output: generated assembly was too large (" + stat.size + " > " + maxSize + " bytes)>";
                     return result;
                 }
                 if (postProcess.length) {
                     var postCommand = 'cat "' + outputFilename + '" | ' + postProcess.join(" | ");
                     return this.exec("bash", ["-c", postCommand], {maxOutput: maxSize})
                         .then(function (postResult) {
                             result.asm = postResult.stdout;
                             if (postResult.code !== 0) {
                                 result.asm = "<Error during post processing: " + postResult.code + ">";
                             }
                             return result;
                         });
                 } else {
                     return this.readFile(outputFilename).then(function (contents) {
                         result.asm = contents.toString();
                         return Promise.resolve(result);
                     });
                 }
             }, this),
             function () {
                 result.asm = "<No output file>";
                 return result;
             }
         );
     }
     if (filters.execute) {
         var maxExecOutputSize = this.env.gccProps("max-executable-output-size", 32 * 1024);
         execPromise = this.execBinary(outputFilename, result, maxExecOutputSize);
     } else {
         execPromise = Promise.resolve("");
     }

     return Promise.all([asmPromise, optPromise, execPromise]);
 };

 Compile.prototype.checkOptions = function (options) {
     var error = this.env.findBadOptions(options);
     if (error.length > 0) return "Bad options: " + error.join(", ");
     return null;
 };

 // This check for arbitrary user-controlled preprocessor inclusions
 // can be circumvented in more than one way. The goal here is to respond
 // to simple attempts with a clear diagnostic; the service still needs to
 // assume that malicious actors can make the compiler open arbitrary files.
 Compile.prototype.checkSource = function (source) {
     var re = /^\s*#\s*i(nclude|mport)(_next)?\s+["<"](\/|.*\.\.)/;
     var failed = [];
     utils.splitLines(source).forEach(function (line, index) {
         if (line.match(re)) {
             failed.push("<stdin>:" + (index + 1) + ":1: no absolute or relative includes please");
         }
     });
     if (failed.length > 0) return failed.join("\n");
     return null;
 };

 Compile.prototype.initialise = function () {
     if (this.getRemote()) return Promise.resolve(this);
     var compiler = this.compiler.exe;
     var versionFlag = this.compiler.versionFlag || '--version';
     var versionRe = new RegExp(this.compiler.versionRe || '.*');
     logger.info("Gathering version information on", compiler);
     return this.exec(compiler, [versionFlag])
         .then(_.bind(function (result) {
                 if (result.code !== 0) {
                     logger.error("Unable to get version for compiler '" + compiler + "' - non-zero result " + result.code);
                     return null;
                 }
                 var version = "";
                 _.each(utils.splitLines(result.stdout + result.stderr), function (line) {
                     if (version) return;
                     var match = line.match(versionRe);
                     if (match) version = match[0];
                 });
                 if (!version) {
                     logger.error("Unable to find compiler version for '" + compiler + "':", result,
                         'with re', versionRe);
                     return null;
                 }
                 logger.info(compiler + " is version '" + version + "'");
                 this.compiler.version = version;
                 if (this.compiler.intelAsm) return this;
                 return this.exec(compiler, ['--target-help'])
                     .then(_.bind(function (result) {
                         var options = {};
                         if (result.code === 0) {
                             var splitness = /--?[-a-zA-Z]+( ?[-a-zA-Z]+)/;
                             utils.eachLine(result.stdout + result.stderr, function (line) {
                                 var match = line.match(splitness);
                                 if (!match) return;
                                 options[match[0]] = true;
                             });
                         }
                         if (options['-masm']) {
                             this.compiler.intelAsm = "-masm=intel";
                             this.compiler.supportsIntel = true;
                         }

                         logger.debug("compiler options: ", options);

                         return this;
                     }, this));
             }, this),
             _.bind(function (err) {
                 logger.error("Unable to get version for compiler '" + compiler + "' - " + err);
                 return null;
             }, this));
 };

 Compile.prototype.getInfo = function () {
     return this.compiler;
 };

 Compile.prototype.getDefaultFilters = function () {
     // TODO; propagate to UI?
     return {
         intel: true,
         commentOnly: true,
         directives: true,
         labels: true
     };
 };

 module.exports = Compile;
	// Copyright (c) 2012-2017, Matt Godbolt
	// All rights reserved.
	//
	// Redistribution and use in source and binary forms, with or without
	// modification, are permitted provided that the following conditions are met:
	//
	// * Redistributions of source code must retain the above copyright notice,
	// this list of conditions and the following disclaimer.
	// * Redistributions in binary form must reproduce the above copyright
	// notice, this list of conditions and the following disclaimer in the
	// documentation and/or other materials provided with the distribution.
	//
	// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
	// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
	// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
	// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
	// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
	// POSSIBILITY OF SUCH DAMAGE.

	var child_process = require('child_process'),
	temp = require('temp'),
	path = require('path'),
	fs = require('fs-extra'),
	Promise = require('promise'), // jshint ignore:line
	asm = require('./asm'),
	utils = require('./utils'),
	quote = require('shell-quote'),
	_ = require('underscore-node'),
	exec = require('./exec'),
	logger = require('./logger').logger,
	compilerOptInfo = require("compiler-opt-info");

	function Compile(compiler, env) {
	this.compiler = compiler;
	this.env = env;
	this.asm = new asm.AsmParser(env.compilerProps);
	this.compiler.supportsIntel = !!this.compiler.intelAsm;
	}

	Compile.prototype.newTempDir = function () {
	return new Promise(function (resolve, reject) {
	temp.mkdir('compiler-explorer-compiler', function (err, dirPath) {
	if (err)
	reject("Unable to open temp file: " + err);
	else
	resolve(dirPath);
	});
	});
	};

	Compile.prototype.writeFile = Promise.denodeify(fs.writeFile);
	Compile.prototype.readFile = Promise.denodeify(fs.readFile);
	Compile.prototype.stat = Promise.denodeify(fs.stat);
	Compile.prototype.couldHaveOptOutput = function (options, version) {
	//TODO(jared): a compiler meta data gatherer could improve this
	return version.toLowerCase().indexOf("clang") > -1 &&
	options.some((x) => x == "-fsave-optimization-record");
	};

	Compile.prototype.getRemote = function () {
	if (this.compiler.exe === null && this.compiler.remote)
	return this.compiler.remote;
	return false;
	};

	Compile.prototype.exec = function (compiler, args, options) {
	// Here only so can be overridden by compiler implementations.
	return exec.execute(compiler, args, options);
	};

	Compile.prototype.runCompiler = function (compiler, options, inputFilename) {
	return this.exec(compiler, options, {
	timeoutMs: this.env.gccProps("compileTimeoutMs", 100),
	maxErrorOutput: this.env.gccProps("max-error-output", 5000),
	env: this.env.getEnv(this.compiler.needsMulti),
	wrapper: this.env.compilerProps("compiler-wrapper")
	}).then(function (result) {
	result.stdout = utils.parseOutput(result.stdout, inputFilename);
	result.stderr = utils.parseOutput(result.stderr, inputFilename);
	return result;
	});
	};

	Compile.prototype.supportsObjdump = function () {
	return this.compiler.objdumper !== "";
	};

	Compile.prototype.objdump = function (outputFilename, result, maxSize, intelAsm) {
	var args = ["-d", "-C", outputFilename, "-l", "--insn-width=16"];
	if (intelAsm) args = args.concat(["-M", "intel"]);
	return this.exec(this.compiler.objdumper, args, {maxOutput: maxSize})
	.then(function (objResult) {
	result.asm = objResult.stdout;
	if (objResult.code !== 0) {
	result.asm = "<No output: objdump returned " + objResult.code + ">";
	}
	return result;
	});
	};

	Compile.prototype.execBinary = function (executable, result, maxSize) {
	return exec.sandbox(executable, [], {maxOutput: maxSize, timeoutMs: 2000}) // TODO make config
	.then(function (execResult) {
	execResult.stdout = utils.parseOutput(execResult.stdout);
	execResult.stderr = utils.parseOutput(execResult.stderr);
	result.execResult = execResult;
	return result;
	}).catch(function (err) {
	// TODO: is this the best way? Perhaps failures in sandbox shouldn't reject
	// with "results", but instead should play on?
	result.execResult = {
	stdout: err.stdout ? utils.parseOutput(err.stdout) : [],
	stderr: err.stderr ? utils.parseOutput(err.stderr) : [],
	code: err.code !== undefined ? err.code : -1
	};
	return result;
	});
	};

	Compile.prototype.filename = function (fn) {
	return fn;
	};

	Compile.prototype.optionsForFilter = function (filters, outputFilename) {
	var options = ['-g', '-o', this.filename(outputFilename)];
	if (this.compiler.intelAsm && filters.intel && !filters.binary) {
	options = options.concat(this.compiler.intelAsm.split(" "));
	}
	if (!filters.binary) options = options.concat('-S');
	return options;
	};

	Compile.prototype.prepareArguments = function (userOptions, filters, inputFilename, outputFilename) {
	var options = this.optionsForFilter(filters, outputFilename);
	if (this.compiler.options) {
	options = options.concat(this.compiler.options.split(" "));
	}
	return options.concat(userOptions \|\| []).concat([this.filename(inputFilename)]);
	};

	Compile.prototype.compile = function (source, options, filters) {
	var self = this;
	var optionsError = self.checkOptions(options);
	if (optionsError) return Promise.reject(optionsError);
	var sourceError = self.checkSource(source);
	if (sourceError) return Promise.reject(sourceError);

	// Don't run binary for unsupported compilers, even if we're asked.
	if (filters.binary && !self.compiler.supportsBinary) {
	delete filters.binary;
	}

	var key = JSON.stringify({compiler: this.compiler, source: source, options: options, filters: filters});
	var cached = this.env.cacheGet(key);
	if (cached) {
	return Promise.resolve(cached);
	}

	if (filters.binary && !source.match(this.env.compilerProps("stubRe"))) {
	source += "\n" + this.env.compilerProps("stubText") + "\n";
	}
	return self.env.enqueue(function () {
	var tempFileAndDirPromise = Promise.resolve().then(function () {
	return self.newTempDir().then(function (dirPath) {
	var inputFilename = path.join(dirPath, self.env.compilerProps("compileFilename"));
	return self.writeFile(inputFilename, source).then(function () {
	return {inputFilename: inputFilename, dirPath: dirPath};
	});
	});
	});

	var compileToAsmPromise = tempFileAndDirPromise.then(function (info) {
	var inputFilename = info.inputFilename;
	var dirPath = info.dirPath;
	var outputFilebase = "output";
	var outputFilename = path.join(dirPath, outputFilebase + ".s"); // NB keep lower case as ldc compiler `tolower`s the output name
	options = self.prepareArguments(options, filters, inputFilename, outputFilename);

	options = options.filter(_.identity);
	return self.runCompiler(self.compiler.exe, options, self.filename(inputFilename))
	.then(function (result) {
	result.dirPath = dirPath;
	if (result.code !== 0) {
	result.asm = "<Compilation failed>";
	return result;
	}
	result.hasOptOutput = false;
	if (self.couldHaveOptOutput(options, self.compiler.version)) {
	const optPath = path.join(dirPath, outputFilebase + ".opt.yaml");
	if (fs.existsSync(optPath)) {
	result.hasOptOutput = true;
	result.optPath = optPath;
	}
	}
	return self.postProcess(result, outputFilename, filters);
	});
	});

	return compileToAsmPromise
	.then(function (results) {
	//TODO(jared): this isn't ideal. Rethink
	var result;
	var optOutput;
	if (results.length) {
	result = results[0];
	optOutput = results[1];
	} else {
	result = results;
	}
	if (result.dirPath) {
	fs.remove(result.dirPath);
	result.dirPath = undefined;
	}
	if (result.okToCache) {
	result.asm = self.asm.process(result.asm, filters);
	} else {
	result.asm = {text: result.asm};
	}
	if (result.hasOptOutput) {
	result.optPath = undefined;
	result.optOutput = optOutput;
	}
	return result;
	})
	.then(_.bind(self.postProcessAsm, self))
	.then(function (result) {
	if (result.okToCache) self.env.cachePut(key, result);
	return result;
	});
	});
	};

	Compile.prototype.postProcessAsm = function (result) {
	if (!result.okToCache) return result;
	var demangler = this.compiler.demangler;
	if (!demangler) return result;
	return this.exec(demangler, [], {input: _.pluck(result.asm, 'text').join("\n")})
	.then(function (demangleResult) {
	var lines = utils.splitLines(demangleResult.stdout);
	for (var i = 0; i < result.asm.length; ++i)
	result.asm[i].text = lines[i];
	return result;
	});
	};

	Compile.prototype.processOptOutput = function (hasOptOutput, optPath) {
	var output = [];
	return new Promise(
	function (resolve, reject) {
	fs.createReadStream(optPath, {encoding: "utf-8"})
	.pipe(new compilerOptInfo.LLVMOptTransformer())
	.on("data", function (opt) {
	output.push(opt);
	})
	.on("end", function () {
	resolve(output);
	});
	});
	};


	Compile.prototype.postProcess = function (result, outputFilename, filters) {
	var postProcess = this.compiler.postProcess.filter(_.identity);
	var maxSize = this.env.gccProps("max-asm-size", 8 * 1024 * 1024);
	var optPromise, asmPromise, execPromise;
	if (result.hasOptOutput) {
	optPromise = this.processOptOutput(result.hasOptOutput, result.optPath);
	} else {
	optPromise = Promise.resolve("");
	}
	if (filters.binary && this.supportsObjdump()) {
	asmPromise = this.objdump(outputFilename, result, maxSize, filters.intel);
	} else {
	asmPromise = this.stat(outputFilename).then(_.bind(function (stat) {
	if (stat.size >= maxSize) {
	result.asm = "<No output: generated assembly was too large (" + stat.size + " > " + maxSize + " bytes)>";
	return result;
	}
	if (postProcess.length) {
	var postCommand = 'cat "' + outputFilename + '" \| ' + postProcess.join(" \| ");
	return this.exec("bash", ["-c", postCommand], {maxOutput: maxSize})
	.then(function (postResult) {
	result.asm = postResult.stdout;
	if (postResult.code !== 0) {
	result.asm = "<Error during post processing: " + postResult.code + ">";
	}
	return result;
	});
	} else {
	return this.readFile(outputFilename).then(function (contents) {
	result.asm = contents.toString();
	return Promise.resolve(result);
	});
	}
	}, this),
	function () {
	result.asm = "<No output file>";
	return result;
	}
	);
	}
	if (filters.execute) {
	var maxExecOutputSize = this.env.gccProps("max-executable-output-size", 32 * 1024);
	execPromise = this.execBinary(outputFilename, result, maxExecOutputSize);
	} else {
	execPromise = Promise.resolve("");
	}

	return Promise.all([asmPromise, optPromise, execPromise]);
	};

	Compile.prototype.checkOptions = function (options) {
	var error = this.env.findBadOptions(options);
	if (error.length > 0) return "Bad options: " + error.join(", ");
	return null;
	};

	// This check for arbitrary user-controlled preprocessor inclusions
	// can be circumvented in more than one way. The goal here is to respond
	// to simple attempts with a clear diagnostic; the service still needs to
	// assume that malicious actors can make the compiler open arbitrary files.
	Compile.prototype.checkSource = function (source) {
	var re = /^\s#\si(nclude\|mport)(_next)?\s+["<"](\/\|.*\.\.)/;
	var failed = [];
	utils.splitLines(source).forEach(function (line, index) {
	if (line.match(re)) {
	failed.push("<stdin>:" + (index + 1) + ":1: no absolute or relative includes please");
	}
	});
	if (failed.length > 0) return failed.join("\n");
	return null;
	};

	Compile.prototype.initialise = function () {
	if (this.getRemote()) return Promise.resolve(this);
	var compiler = this.compiler.exe;
	var versionFlag = this.compiler.versionFlag \|\| '--version';
	var versionRe = new RegExp(this.compiler.versionRe \|\| '.*');
	logger.info("Gathering version information on", compiler);
	return this.exec(compiler, [versionFlag])
	.then(_.bind(function (result) {
	if (result.code !== 0) {
	logger.error("Unable to get version for compiler '" + compiler + "' - non-zero result " + result.code);
	return null;
	}
	var version = "";
	_.each(utils.splitLines(result.stdout + result.stderr), function (line) {
	if (version) return;
	var match = line.match(versionRe);
	if (match) version = match[0];
	});
	if (!version) {
	logger.error("Unable to find compiler version for '" + compiler + "':", result,
	'with re', versionRe);
	return null;
	}
	logger.info(compiler + " is version '" + version + "'");
	this.compiler.version = version;
	if (this.compiler.intelAsm) return this;
	return this.exec(compiler, ['--target-help'])
	.then(_.bind(function (result) {
	var options = {};
	if (result.code === 0) {
	var splitness = /--?[-a-zA-Z]+( ?[-a-zA-Z]+)/;
	utils.eachLine(result.stdout + result.stderr, function (line) {
	var match = line.match(splitness);
	if (!match) return;
	options[match[0]] = true;
	});
	}
	if (options['-masm']) {
	this.compiler.intelAsm = "-masm=intel";
	this.compiler.supportsIntel = true;
	}

	logger.debug("compiler options: ", options);

	return this;
	}, this));
	}, this),
	_.bind(function (err) {
	logger.error("Unable to get version for compiler '" + compiler + "' - " + err);
	return null;
	}, this));
	};

	Compile.prototype.getInfo = function () {
	return this.compiler;
	};

	Compile.prototype.getDefaultFilters = function () {
	// TODO; propagate to UI?
	return {
	intel: true,
	commentOnly: true,
	directives: true,
	labels: true
	};
	};

	module.exports = Compile;