The Tor Browser: js/src/jit-test/etc/generate-lookupswitch-tests.js@6474c204b198 (annotated)

js/src/jit-test/etc/generate-lookupswitch-tests.js@6474c204b198 (annotated)

js/src/jit-test/etc/generate-lookupswitch-tests.js

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /**
  * A test case spec is an array of objects of the following kind:
  *  { 'match': Num|Str|Null,
  *    'body': Num|Str|Null,
  *    'fallthrough': Boolean }
  *
  * If the 'match' is null, then it represents a 'default:'
  * If the 'match' is not null, it represents a 'case X:' where X is the value.
  * If the 'body' is null, then it means that the case body is empty.  Otherwise,
  * it means that the case body is a single 'arr.push(V);' where "arr" is an input
  * array to the function containing the switch statement, and V is the value.
  * If 'fallthrough' is false, then the body is terminated with a break, otherwise
  * it is not.
  *
  * So a spec: [{'match':3, 'body':null, 'fallthrough':false}, {'match':null, 'body':"foo", 'fallthrough':true}]
  * Represents a switch function:
  *  function(x, arr) {
  *      switch(x) {
  *      case 3:
  *          break;
  *      default:
  *          arr.push('foo');
  *      }
  *  }
  *
  * GenerateSpecPermutes generates a bunch of relevant specs, using the given case match-values,
  * and appends them to result the array passed into it.
  *
  * InterpretSwitch takes a spec, a value, and a result array, and behaves as if the switch specified
  * by the spec had been called on the value and the result array.
  *
  * VerifySwitchSpec is there but not used in the code.  I was using it while testing the test case
  * generator.  It verifies that a switch spec is sane.
  *
  * RunSpec uses eval to run the test directly.  It's not used currently.
  *
  * GenerateSwitchCode generates a string of the form "function NAME(x, arg) { .... }" which
  * contains the switch modeled by its input spec.
  *
  * RunTest is there to be used from within the generated script.  Its code is dumped out
  * to the generated script text, and invoked there.
  *
  * Hope all of this makes some sort of sense.
  *  -kannan
  */
 /** HELPERS **/
 function ASSERT(cond, msg) { assertEq(cond, true, msg); }
 function IsUndef(x) { return typeof(x) == 'undefined'; }
 function IsNull(x) { return typeof(x) == 'object' && x == null; }
 function IsNum(x) { return typeof(x) == 'number'; }
 function IsStr(x) { return typeof(x) == 'string'; }
 function IsBool(x) { return typeof(x) == 'boolean'; }
 function Repr(x) {
     ASSERT(IsNum(x) || IsStr(x), "Repr");
     if(IsNum(x)) { return ""+x; }
     else { return "'"+x+"'"; }
 }
 function RandBool() { return Math.random() >= 0.5; }
 function RandInt(max) {
     if(IsUndef(max)) { max = 0x7fffffff; }
     return (Math.random() * max)|0;
 }
 var CHARS = "abcdefghijklmnopqrstuvywxyzABCDEFGHIJKLMNOPQRSTUVYWXYZ0123456789~!@#$%^&*()-_=+{}[]";
 function RandStr() {
     var arr = [];
     var len = Math.floor(Math.random() * 10) + 1;
     for(var i = 0; i < len; i++) {
         var c = Math.floor(Math.random() * CHARS.length);
         arr.push(CHARS[c]);
     }
     return arr.join('');
 }
 function RandVal() { return RandBool() ? RandInt() : RandStr(); }
 /**
  * Compare two arrays and ensure they are equal.
  */
 function ArraysEqual(arr1, arr2) {
     ASSERT(arr1.length == arr2.length, "Lengths not equal");
     for(var i = 0; i < arr1.length; i++) {
         ASSERT(typeof(arr1[i]) == typeof(arr2[i]), "Types not equal for position " + i);
         ASSERT(arr1[i] == arr2[i], "Values not equal for position " + i);
     }
 }
 function VerifySwitchSpec(spec) {
     var foundDefault = undefined;
     for(var i = 0; i < spec.length; i++) {
         var caseSpec = spec[i],
             match = caseSpec.match,
             body = caseSpec.body,
             fallthrough = caseSpec.fallthrough;
         ASSERT(IsNum(match) || IsStr(match) || IsNull(match), "Invalid case match for " + i);
         ASSERT(IsNum(body) || IsStr(body) || IsNull(body), "Invalid case body for " + i);
         ASSERT(IsBool(fallthrough), "Invalid fallthrough for " + i);
         if(IsNull(match)) {
             ASSERT(IsUndef(foundDefault), "Duplicate default found at " + i);
             foundDefault = i;
         }
     }
 }
 /**
  * Do a manual interpretation of a particular spec, given an input
  * and outputting to an output array.
  */
 function InterpretSwitch(spec, input, outputArray) {
     var foundMatch = undefined, foundDefault = undefined;
     // Go through cases, trying to find a matching clause.
     for(var i = 0; i < spec.length; i++) {
         var caseSpec = spec[i], match = caseSpec.match;
         if(IsNull(match)) {
             foundDefault = i;
             continue;
         } else if(match === input) {
             foundMatch = i;
             break;
         }
     }
     // Select either matching clause or default.
     var matchI = IsNum(foundMatch) ? foundMatch : foundDefault;
     // If match or default was found, interpret body from that point on.
     if(IsNum(matchI)) {
         for(var i = matchI; i < spec.length; i++) {
             var caseSpec = spec[i],
                 match = caseSpec.match,
                 body = caseSpec.body,
                 fallthrough = caseSpec.fallthrough;
             if(!IsNull(body)) { outputArray.push(body); }
             if(!fallthrough) { break; }
         }
     }
 }
 /**
  * Generate the code string for a javascript function containing the
  * switch specified by the spec, in pure JS syntax.
  */
 function GenerateSwitchCode(spec, name) {
     var lines = [];
     if(!name) { name = ""; }
     lines.push("function "+name+"(x, arr) {");
     lines.push("    switch(x) {");
     for(var i = 0; i < spec.length; i++) {
         var caseSpec = spec[i],
             match = caseSpec.match,
             body = caseSpec.body,
             fallthrough = caseSpec.fallthrough;
         if(IsNull(match))   { lines.push("    default:"); }
         else                { lines.push("    case "+Repr(match)+":"); }
         if(!IsNull(body))   { lines.push("        arr.push("+Repr(body)+");"); }
         if(!fallthrough)    { lines.push("        break;"); }
     }
     lines.push("    }");
     lines.push("}");
     return lines.join("\n");
 }
 /**
  * Generates all possible specs for a given set of case match values.
  */
 function GenerateSpecPermutes(matchVals, resultArray) {
     ASSERT((0 < matchVals.length) && (matchVals.length <= 5), "Invalid matchVals");
     var maxPermuteBody = (1 << matchVals.length) - 1;
     for(var bod_pm = 0; bod_pm <= maxPermuteBody; bod_pm++) {
         var maxPermuteFallthrough = (1 << matchVals.length) - 1;
         for(var ft_pm = 0; ft_pm <= maxPermuteFallthrough; ft_pm++) {
             // use bod_m and ft_pm to decide the placement of null vs value bodies,
             // and the placement of fallthroughs vs breaks.
             // Empty bodies always fall through, so fallthrough bitmask 1s must be
             // a subset of the body bitmask 1s.
             if((bod_pm | ft_pm) != bod_pm) {
                 continue;
             }
             var spec = [];
             for(var k = 0; k < matchVals.length; k++) {
                 var match = matchVals[k];
                 var body = ((bod_pm & (1 << k)) > 0) ? null : RandVal();
                 var fallthrough = ((ft_pm & (1 << k)) > 0) ? true : false;
                 var caseSpec = {'match':match, 'body':body, 'fallthrough':fallthrough};
                 spec.push(caseSpec);
             }
             // Variant specs for following cases:
             // Default with empty body, fallthrough
             GenerateDefaultPermutes(spec, null, true, resultArray);
             // Default with nonempty body, fallthrough
             GenerateDefaultPermutes(spec, RandVal(), true, resultArray);
             // Default with nonempty body, break
             GenerateDefaultPermutes(spec, RandVal(), false, resultArray);
         }
     }
 }
 function GenerateDefaultPermutes(spec, body, fallthrough, resultArray) {
     if(spec.length <= 2) {
         for(var i = 0; i <= spec.length; i++) {
             var copy = CopySpec(spec);
             if(IsNull(body)) {
                 copy.splice(i,0,{'match':null, 'body':null, 'fallthrough':true});
             } else {
                 copy.splice(i,0,{'match':null, 'body':body, 'fallthrough':fallthrough});
             }
             resultArray.push(copy);
         }
     } else {
         var posns = [0, Math.floor(spec.length / 2), spec.length];
         posns.forEach(function (i) {
             var copy = CopySpec(spec);
             if(IsNull(body)) {
                 copy.splice(i,0,{'match':null, 'body':null, 'fallthrough':true});
             } else {
                 copy.splice(i,0,{'match':null, 'body':body, 'fallthrough':fallthrough});
             }
             resultArray.push(copy);
         });
     }
 }
 function CopySpec(spec) {
     var newSpec = [];
     for(var i = 0; i < spec.length; i++) {
         var caseSpec = spec[i];
         newSpec.push({'match':caseSpec.match,
                       'body':caseSpec.body,
                       'fallthrough':caseSpec.fallthrough});
     }
     return newSpec;
 }
 function RunSpec(spec, matchVals) {
     var code = GenerateSwitchCode(spec);
     // Generate roughly 200 inputs for the test case spec, exercising
     // every match value, as well as 3 randomly generated values for every
     // iteration of the match values.
     var inputs = [];
     while(inputs.length < 500) {
         for(var i = 0; i < matchVals.length; i++) { inputs.push(matchVals[i]); }
         for(var i = 0; i < 3; i++) { inputs.push(RandVal()); }
     }
     // Interpret the lookupswitch with the inputs.
     var interpResults = [];
     for(var i = 0; i < inputs.length; i++) {
         InterpretSwitch(spec, inputs[i], interpResults);
     }
     // Run compiled lookupswitch with the inputs.
     var fn = eval("_ = " + code);
     print("Running spec: " + code);
     var compileResults = RunCompiled(fn, inputs);
     print("Done Running spec");
     // Verify that they produce the same output.
     ASSERT(interpResults.length == compileResults.length, "Length mismatch");
     for(var i = 0; i < interpResults.length; i++) {
         ASSERT(interpResults[i] == compileResults[i], "Value mismatch");
     }
 }
 function RunCompiled(fn, inputs) {
     var results = [];
     var len = inputs.length;
     for(var i = 0; i < len; i++) { fn(inputs[i], results); }
     return results;
 }
 function PrintSpec(spec, inputs, fname) {
     var code = GenerateSwitchCode(spec, fname);
     var input_s = fname + ".INPUTS = [" + inputs.map(Repr).join(', ') + "];";
     var spec_s = fname + ".SPEC = " + JSON.stringify(spec) + ";";
     print(code + "\n" + input_s + "\n" + spec_s);
 }
 function RunTest(test) {
     // Exercise every test case as well as one case which won't match with any of the
     // ("But what if it randomly generates a string case match whose value is
     //   UNMATCHED_CASE?!", you ask incredulously.  Well, RandStr limits itself to 11 chars.
     //   So there.)
     var inputs = test.INPUTS;
     inputs.push("UNMATCHED_CASE");
     var spec = test.SPEC;
     var results1 = [];
     for(var i = 0; i < 80; i++) {
         for(var j = 0; j < inputs.length; j++) {
             test(inputs[j], results1);
         }
     }
     var results2 = [];
     for(var i = 0; i < 80; i++) {
         for(var j = 0; j < inputs.length; j++) {
             InterpretSwitch(spec, inputs[j], results2);
         }
     }
     ArraysEqual(results1, results2);
 }
 // NOTES:
 //  * RunTest is used within the generated test script.
 //  * InterpretSwitch is printed out into the generated test script.
 print("/////////////////////////////////////////");
 print("// This is a generated file!");
 print("// See jit-tests/etc/generate-lookupswitch-tests.js for the code");
 print("// that generated this code!");
 print("/////////////////////////////////////////");
 print("");
 print("/////////////////////////////////////////");
 print("// PRELUDE                             //");
 print("/////////////////////////////////////////");
 print("");
 print("// Avoid eager compilation of the global-scope.");
 print("try{} catch (x) {};");
 print("");
 print(ASSERT);
 print(IsNull);
 print(IsNum);
 print(ArraysEqual);
 print(InterpretSwitch);
 print(RunTest);
 print("");
 print("/////////////////////////////////////////");
 print("// TEST CASES                          //");
 print("/////////////////////////////////////////");
 print("");
 print("var TESTS = [];");
 var MATCH_SETS = [["foo", "bar", "zing"]];
 var count = 0;
 for(var i = 0; i < MATCH_SETS.length; i++) {
     var matchSet = MATCH_SETS[i];
     var specs = [];
     GenerateSpecPermutes(matchSet, specs);
     for(var j = 0; j < specs.length; j++) {
         count++;
         PrintSpec(specs[j], matchSet.slice(), 'test_'+count);
         print("TESTS.push(test_"+count+");\n");
     }
 }
 print("");
 print("/////////////////////////////////////////");
 print("// RUNNER                              //");
 print("/////////////////////////////////////////");
 print("");
 print("for(var i = 0; i < TESTS.length; i++) {");
 print("  RunTest(TESTS[i]);");
 print("}");