lib/asm.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 _ = require('underscore-node');
 var utils = require('./utils');

 function AsmParser(compilerProps) {
     var labelFind = /[.a-zA-Z_][a-zA-Z0-9$_.]*/g;
     var dataDefn = /\.(string|asciz|ascii|[1248]?byte|short|word|long|quad|value|zero)/;
     var fileFind = /^\s*\.file\s+(\d+)\s+"([^"]+)"(\s+"([^"]+)")?.*/;
     var hasOpcode = /^\s*([a-zA-Z$_][a-zA-Z0-9$_.]*:\s*)?[a-zA-Z].*/;
     var definesFunction = /^\s*\.type.*,\s*[@%]function$/;
     var labelDef = /^([.a-zA-Z_$][a-zA-Z0-9$_.]+):/;
     var directive = /^\s*\..*$/;

     function filterAsmLine(line, filters) {
         if (!filters.trim) return line;
         var splat = line.split(/\s+/);
         if (splat[0] === "") {
             // An indented line: preserve a two-space indent
             return "  " + splat.slice(1).join(" ");
         } else {
             return splat.join(" ");
         }
     }

     function findUsedLabels(asmLines, filterDirectives) {
         var labelsUsed = {};
         var weakUsages = {};
         var currentLabel = "";

         // Scan through looking for definite label usages (ones used by opcodes),
         // and ones that are weakly used: that is, their use is conditional on another label.
         // For example:
         // .foo: .string "moo"
         // .baz: .quad .foo
         //       mov eax, .baz
         // In this case, the '.baz' is used by an opcode, and so is strongly used.
         // The '.foo' is weakly used by .baz.
         asmLines.forEach(function (line) {
             var match = line.match(labelDef);
             if (match)
                 currentLabel = match[1];
             if (!line || line[0] === '.') return;

             match = line.match(labelFind);
             if (!match) return;

             if (!filterDirectives || line.match(hasOpcode) || line.match(definesFunction)) {
                 // Only count a label as used if it's used by an opcode, or else we're not filtering directives.
                 match.forEach(function (label) {
                     labelsUsed[label] = true;
                 });
             } else if (currentLabel) {
                 // If we have a current label, then any subsequent opcode or data definition's labels are refered to
                 // weakly by that label.
                 var isDataDefinition = !!line.match(dataDefn);
                 var isOpcode = !line.match(directive); // We assume anything that's not a directive is an opcode.
                 if (isDataDefinition || isOpcode) {
                     if (!weakUsages[currentLabel]) weakUsages[currentLabel] = [];
                     match.forEach(function (label) {
                         weakUsages[currentLabel].push(label);
                     });
                 }
             }
         });

         // Now follow the chains of used labels, marking any weak references they refer
         // to as also used. We iteratively do this until either no new labels are found,
         // or we hit a limit (only here to prevent a pathological case from hanging).
         function markUsed(label) {
             labelsUsed[label] = true;
         }

         var MaxLabelIterations = 10;
         for (var iter = 0; iter < MaxLabelIterations; ++iter) {
             var toAdd = [];
             _.each(labelsUsed, function (t, label) { // jshint ignore:line
                 _.each(weakUsages[label], function (nowused) {
                     if (labelsUsed[nowused]) return;
                     toAdd.push(nowused);
                 });
             });
             if (!toAdd) break;
             _.each(toAdd, markUsed);
         }
         return labelsUsed;
     }

     function parseFiles(asmLines) {
         var files = {};
         asmLines.forEach(function (line) {
             var match = line.match(fileFind);
             if (match) {
                 var lineNum = parseInt(match[1]);
                 if (match[3]) {
                     // Clang-style file directive '.file X "dir" "filename"'
                     files[lineNum] = match[2] + "/" + match[3];
                 } else {
                     files[lineNum] = match[2];
                 }
             }
         });
         return files;
     }

     function processAsm(asm, filters) {
         if (filters.binary) return processBinaryAsm(asm, filters);

         var result = [];
         var asmLines = utils.splitLines(asm);
         var labelsUsed = findUsedLabels(asmLines, filters.directives);
         var files = parseFiles(asmLines);
         var prevLabel = "";

         var commentOnly = /^\s*(((#|@|\/\/).*)|(\/\*.*\*\/))$/;
         var sourceTag = /^\s*\.loc\s+(\d+)\s+(\d+).*/;
         var sourceStab = /^\s*\.stabn\s+(\d+),0,(\d+),.*/;
         var stdInLooking = /.*<stdin>|^-$|example\.[^/]+$/;
         var endBlock = /\.(cfi_endproc|data|text|section)/;
         var source = null;
         asmLines.forEach(function (line) {
             var match;
             if (line.trim() === "") {
                 result.push({text: "", source: null});
                 return;
             }
             if (!!(match = line.match(sourceTag))) {
                 var file = files[parseInt(match[1])];
                 var sourceLine = parseInt(match[2]);
                 if (file) {
                     if (file.match(stdInLooking))
                         source = {'file': null, 'line': sourceLine};
                     else
                         source = {'file': file, 'line': sourceLine};
                 } else {
                     source = null;
                 }
             }
             if (!!(match = line.match(sourceStab))) {
                 // cf http://www.math.utah.edu/docs/info/stabs_11.html#SEC48
                 switch (parseInt(match[1])) {
                     case 68:
                         source = {'file': null, 'line': parseInt(match[2])};
                         break;
                     case 132:
                     case 100:
                         source = null;
                         prevLabel = null;
                         break;
                 }
             }
             if (line.match(endBlock)) {
                 source = null;
                 prevLabel = null;
             }

             if (filters.commentOnly && line.match(commentOnly)) return;

             match = line.match(labelDef);
             if (match) {
                 // It's a label definition.
                 if (labelsUsed[match[1]] === undefined) {
                     // It's an unused label.
                     if (filters.labels) return;
                 } else {
                     // A used label.
                     prevLabel = match;
                 }
             }
             if (!match && filters.directives) {
                 // Check for directives only if it wasn't a label; the regexp would
                 // otherwise misinterpret labels as directives.
                 if (line.match(dataDefn) && prevLabel) {
                     // We're defining data that's being used somewhere.
                 } else {
                     if (line.match(directive)) return;
                 }
             }

             var hasOpcodeMatch = line.match(hasOpcode);
             line = utils.expandTabs(line);
             result.push({text: filterAsmLine(line, filters), source: hasOpcodeMatch ? source : null});
         });
         return result;
     }

     var binaryHideFuncRe = null;
     var maxAsmLines = 500;

     function isUserFunction(func) {
         return !func.match(binaryHideFuncRe);
     }

     function processBinaryAsm(asm, filters) {
         var result = [];
         var asmLines = asm.split("\n");
         var asmOpcodeRe = /^\s*([0-9a-f]+):\s*(([0-9a-f][0-9a-f] ?)+)\s*(.*)/;
         var lineRe = /^(\/[^:]+):([0-9]+).*/;
         var labelRe = /^([0-9a-f]+)\s+<([^>]+)>:$/;
         var destRe = /.*\s([0-9a-f]+)\s+<([^>]+)>$/;
         var source = null;
         var func = null;

         // Handle "error" documents.
         if (asmLines.length === 1 && asmLines[0][0] === '<') {
             return [{text: asmLines[0], source: null}];
         }

         asmLines.forEach(function (line) {
             if (result.length >= maxAsmLines) {
                 if (result.length == maxAsmLines) {
                     result.push({text: "[truncated; too many lines]", source: null});
                 }
                 return;
             }
             var match = line.match(lineRe);
             if (match) {
                 source = parseInt(match[2]);
                 return;
             }

             match = line.match(labelRe);
             if (match) {
                 func = match[2];
                 if (isUserFunction(func)) {
                     result.push({text: func + ":", source: null});
                 }
                 return;
             }

             if (!func || !isUserFunction(func)) return;

             match = line.match(asmOpcodeRe);
             if (match) {
                 var address = parseInt(match[1], 16);
                 var opcodes = match[2].split(" ").filter(function (x) {
                     return x;
                 });
                 var disassembly = " " + filterAsmLine(match[4], filters);
                 var links = null;
                 var destMatch = line.match(destRe);
                 if (destMatch) {
                     links = [{
                         offset: disassembly.indexOf(destMatch[1]),
                         length: destMatch[1].length,
                         to: parseInt(destMatch[1], 16)
                     }];
                 }
                 result.push({opcodes: opcodes, address: address, text: disassembly, source: source, links: links});
             } else {
                 //result.push({text: line, source: null});
             }
         });
         return result;
     }

     if (compilerProps) {
         binaryHideFuncRe = new RegExp(compilerProps('binaryHideFuncRe'));
         maxAsmLines = compilerProps('maxLinesOfAsm', maxAsmLines);
     }
     this.process = function (asm, filters) {
         return processAsm(asm, filters);
     };
 }

 module.exports = {
     AsmParser: AsmParser
 };
	// 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 _ = require('underscore-node');
	var utils = require('./utils');

	function AsmParser(compilerProps) {
	var labelFind = /[.a-zA-Z_][a-zA-Z0-9$_.]*/g;
	var dataDefn = /\.(string\|asciz\|ascii\|[1248]?byte\|short\|word\|long\|quad\|value\|zero)/;
	var fileFind = /^\s\.file\s+(\d+)\s+"([^"]+)"(\s+"([^"]+)")?./;
	var hasOpcode = /^\s([a-zA-Z$_][a-zA-Z0-9$_.]:\s)?[a-zA-Z]./;
	var definesFunction = /^\s\.type.,\s*[@%]function$/;
	var labelDef = /^([.a-zA-Z_$][a-zA-Z0-9$_.]+):/;
	var directive = /^\s\..$/;

	function filterAsmLine(line, filters) {
	if (!filters.trim) return line;
	var splat = line.split(/\s+/);
	if (splat[0] === "") {
	// An indented line: preserve a two-space indent
	return " " + splat.slice(1).join(" ");
	} else {
	return splat.join(" ");
	}
	}

	function findUsedLabels(asmLines, filterDirectives) {
	var labelsUsed = {};
	var weakUsages = {};
	var currentLabel = "";

	// Scan through looking for definite label usages (ones used by opcodes),
	// and ones that are weakly used: that is, their use is conditional on another label.
	// For example:
	// .foo: .string "moo"
	// .baz: .quad .foo
	// mov eax, .baz
	// In this case, the '.baz' is used by an opcode, and so is strongly used.
	// The '.foo' is weakly used by .baz.
	asmLines.forEach(function (line) {
	var match = line.match(labelDef);
	if (match)
	currentLabel = match[1];
	if (!line \|\| line[0] === '.') return;

	match = line.match(labelFind);
	if (!match) return;

	if (!filterDirectives \|\| line.match(hasOpcode) \|\| line.match(definesFunction)) {
	// Only count a label as used if it's used by an opcode, or else we're not filtering directives.
	match.forEach(function (label) {
	labelsUsed[label] = true;
	});
	} else if (currentLabel) {
	// If we have a current label, then any subsequent opcode or data definition's labels are refered to
	// weakly by that label.
	var isDataDefinition = !!line.match(dataDefn);
	var isOpcode = !line.match(directive); // We assume anything that's not a directive is an opcode.
	if (isDataDefinition \|\| isOpcode) {
	if (!weakUsages[currentLabel]) weakUsages[currentLabel] = [];
	match.forEach(function (label) {
	weakUsages[currentLabel].push(label);
	});
	}
	}
	});

	// Now follow the chains of used labels, marking any weak references they refer
	// to as also used. We iteratively do this until either no new labels are found,
	// or we hit a limit (only here to prevent a pathological case from hanging).
	function markUsed(label) {
	labelsUsed[label] = true;
	}

	var MaxLabelIterations = 10;
	for (var iter = 0; iter < MaxLabelIterations; ++iter) {
	var toAdd = [];
	_.each(labelsUsed, function (t, label) { // jshint ignore:line
	_.each(weakUsages[label], function (nowused) {
	if (labelsUsed[nowused]) return;
	toAdd.push(nowused);
	});
	});
	if (!toAdd) break;
	_.each(toAdd, markUsed);
	}
	return labelsUsed;
	}

	function parseFiles(asmLines) {
	var files = {};
	asmLines.forEach(function (line) {
	var match = line.match(fileFind);
	if (match) {
	var lineNum = parseInt(match[1]);
	if (match[3]) {
	// Clang-style file directive '.file X "dir" "filename"'
	files[lineNum] = match[2] + "/" + match[3];
	} else {
	files[lineNum] = match[2];
	}
	}
	});
	return files;
	}

	function processAsm(asm, filters) {
	if (filters.binary) return processBinaryAsm(asm, filters);

	var result = [];
	var asmLines = utils.splitLines(asm);
	var labelsUsed = findUsedLabels(asmLines, filters.directives);
	var files = parseFiles(asmLines);
	var prevLabel = "";

	var commentOnly = /^\s(((#\|@\|\/\/).)\|(\/\.\*\/))$/;
	var sourceTag = /^\s\.loc\s+(\d+)\s+(\d+)./;
	var sourceStab = /^\s\.stabn\s+(\d+),0,(\d+),./;
	var stdInLooking = /.*<stdin>\|^-$\|example\.[^/]+$/;
	var endBlock = /\.(cfi_endproc\|data\|text\|section)/;
	var source = null;
	asmLines.forEach(function (line) {
	var match;
	if (line.trim() === "") {
	result.push({text: "", source: null});
	return;
	}
	if (!!(match = line.match(sourceTag))) {
	var file = files[parseInt(match[1])];
	var sourceLine = parseInt(match[2]);
	if (file) {
	if (file.match(stdInLooking))
	source = {'file': null, 'line': sourceLine};
	else
	source = {'file': file, 'line': sourceLine};
	} else {
	source = null;
	}
	}
	if (!!(match = line.match(sourceStab))) {
	// cf http://www.math.utah.edu/docs/info/stabs_11.html#SEC48
	switch (parseInt(match[1])) {
	case 68:
	source = {'file': null, 'line': parseInt(match[2])};
	break;
	case 132:
	case 100:
	source = null;
	prevLabel = null;
	break;
	}
	}
	if (line.match(endBlock)) {
	source = null;
	prevLabel = null;
	}

	if (filters.commentOnly && line.match(commentOnly)) return;

	match = line.match(labelDef);
	if (match) {
	// It's a label definition.
	if (labelsUsed[match[1]] === undefined) {
	// It's an unused label.
	if (filters.labels) return;
	} else {
	// A used label.
	prevLabel = match;
	}
	}
	if (!match && filters.directives) {
	// Check for directives only if it wasn't a label; the regexp would
	// otherwise misinterpret labels as directives.
	if (line.match(dataDefn) && prevLabel) {
	// We're defining data that's being used somewhere.
	} else {
	if (line.match(directive)) return;
	}
	}

	var hasOpcodeMatch = line.match(hasOpcode);
	line = utils.expandTabs(line);
	result.push({text: filterAsmLine(line, filters), source: hasOpcodeMatch ? source : null});
	});
	return result;
	}

	var binaryHideFuncRe = null;
	var maxAsmLines = 500;

	function isUserFunction(func) {
	return !func.match(binaryHideFuncRe);
	}

	function processBinaryAsm(asm, filters) {
	var result = [];
	var asmLines = asm.split("\n");
	var asmOpcodeRe = /^\s([0-9a-f]+):\s(([0-9a-f][0-9a-f] ?)+)\s(.)/;
	var lineRe = /^(\/[^:]+):([0-9]+).*/;
	var labelRe = /^([0-9a-f]+)\s+<([^>]+)>:$/;
	var destRe = /.*\s([0-9a-f]+)\s+<([^>]+)>$/;
	var source = null;
	var func = null;

	// Handle "error" documents.
	if (asmLines.length === 1 && asmLines[0][0] === '<') {
	return [{text: asmLines[0], source: null}];
	}

	asmLines.forEach(function (line) {
	if (result.length >= maxAsmLines) {
	if (result.length == maxAsmLines) {
	result.push({text: "[truncated; too many lines]", source: null});
	}
	return;
	}
	var match = line.match(lineRe);
	if (match) {
	source = parseInt(match[2]);
	return;
	}

	match = line.match(labelRe);
	if (match) {
	func = match[2];
	if (isUserFunction(func)) {
	result.push({text: func + ":", source: null});
	}
	return;
	}

	if (!func \|\| !isUserFunction(func)) return;

	match = line.match(asmOpcodeRe);
	if (match) {
	var address = parseInt(match[1], 16);
	var opcodes = match[2].split(" ").filter(function (x) {
	return x;
	});
	var disassembly = " " + filterAsmLine(match[4], filters);
	var links = null;
	var destMatch = line.match(destRe);
	if (destMatch) {
	links = [{
	offset: disassembly.indexOf(destMatch[1]),
	length: destMatch[1].length,
	to: parseInt(destMatch[1], 16)
	}];
	}
	result.push({opcodes: opcodes, address: address, text: disassembly, source: source, links: links});
	} else {
	//result.push({text: line, source: null});
	}
	});
	return result;
	}

	if (compilerProps) {
	binaryHideFuncRe = new RegExp(compilerProps('binaryHideFuncRe'));
	maxAsmLines = compilerProps('maxLinesOfAsm', maxAsmLines);
	}
	this.process = function (asm, filters) {
	return processAsm(asm, filters);
	};
	}

	module.exports = {
	AsmParser: AsmParser
	};