1 files changed, 267 insertions, 0 deletions
diff --git a/js/src/devtools/rootAnalysis/dumpCFG.js b/js/src/devtools/rootAnalysis/dumpCFG.js
new file mode 100644
index 0000000000..ac4897669b
--- /dev/null
+++ b/js/src/devtools/rootAnalysis/dumpCFG.js
@@ -0,0 +1,267 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// const cfg = loadCFG(scriptArgs[0]);
+// dump_CFG(cfg);
+
+function loadCFG(filename) {
+  const data = os.file.readFile(filename);
+  return JSON.parse(data);
+}
+
+function dump_CFG(cfg) {
+  for (const body of cfg)
+    dump_body(body);
+}
+
+function dump_body(body, src, dst) {
+  const {BlockId,Command,DefineVariable,Index,Location,PEdge,PPoint,Version} = body;
+
+  const [mangled, unmangled] = splitFunction(BlockId.Variable.Name[0]);
+  print(`${unmangled} at ${Location[0].CacheString}:${Location[0].Line}`);
+
+  if (src === undefined) {
+    for (const def of DefineVariable)
+      print(str_definition(def));
+    print("");
+  }
+
+  for (const edge of PEdge) {
+    if (src === undefined || edge.Index[0] == src) {
+      if (dst == undefined || edge.Index[1] == dst)
+        print(str_edge(edge, body));
+    }
+  }
+}
+
+function str_definition(def) {
+  const {Type, Variable} = def;
+  return `define ${str_Variable(Variable)} : ${str_Type(Type)}`;
+}
+
+function badFormat(what, val) {
+  printErr("Bad format of " + what + ": " + JSON.stringify(val, null, 4));
+  printErr((new Error).stack);
+}
+
+function str_Variable(variable) {
+  if (variable.Kind == 'Return')
+    return '<returnval>';
+  else if (variable.Kind == 'This')
+    return 'this';
+
+  try {
+    return variable.Name[1];
+  } catch(e) {
+    badFormat("variable", variable);
+  }
+}
+
+function str_Type(type) {
+  try {
+    const {Kind, Type, Name, TypeFunctionArguments} = type;
+    if (Kind == 'Pointer')
+      return str_Type(Type) + "*";
+    else if (Kind == 'CSU')
+      return Name;
+    else if (Kind == 'Array')
+      return str_Type(Type) + "[]";
+
+    return Kind;
+  } catch(e) {
+    badFormat("type", type);
+  }
+}
+
+var OpCodeNames = {
+  'LessEqual': ['<=', '>'],
+  'LessThan': ['<', '>='],
+  'GreaterEqual': ['>=', '<'],
+  'Greater': ['>', '<='],
+  'Plus': '+',
+  'Minus': '-',
+};
+
+function opcode_name(opcode, invert) {
+  if (opcode in OpCodeNames) {
+    const name = OpCodeNames[opcode];
+    if (invert === undefined)
+      return name;
+    return name[invert ? 1 : 0];
+  } else {
+    if (invert === undefined)
+      return opcode;
+    return (invert ? '!' : '') + opcode;
+  }
+}
+
+function str_value(val, env, options) {
+  const {Kind, Variable, String, Exp} = val;
+  if (Kind == 'Var')
+    return str_Variable(Variable);
+  else if (Kind == 'Drf') {
+    // Suppress the vtable lookup dereference
+    if (Exp[0].Kind == 'Fld' && "FieldInstanceFunction" in Exp[0].Field)
+      return str_value(Exp[0], env);
+    const exp = str_value(Exp[0], env);
+    if (options && options.noderef)
+      return exp;
+    return "*" + exp;
+  } else if (Kind == 'Fld') {
+    const {Exp, Field} = val;
+    const name = Field.Name[0];
+    if ("FieldInstanceFunction" in Field) {
+      return Field.FieldCSU.Type.Name + "." + name;
+    }
+    const container = str_value(Exp[0]);
+    if (container.startsWith("*"))
+      return container.substring(1) + "->" + name;
+    return container + "." + name;
+  } else if (Kind == 'Empty') {
+    return '<unknown>';
+  } else if (Kind == 'Binop') {
+    const {OpCode} = val;
+    const op = opcode_name(OpCode);
+    return `${str_value(Exp[0], env)} ${op} ${str_value(Exp[1], env)}`;
+  } else if (Kind == 'Unop') {
+    const exp = str_value(Exp[0], env);
+    const {OpCode} = val;
+    if (OpCode == 'LogicalNot')
+      return `not ${exp}`;
+    return `${OpCode}(${exp})`;
+  } else if (Kind == 'Index') {
+    const index = str_value(Exp[1], env);
+    if (Exp[0].Kind == 'Drf')
+      return `${str_value(Exp[0], env, {noderef:true})}[${index}]`;
+    else
+      return `&${str_value(Exp[0], env)}[${index}]`;
+  } else if (Kind == 'NullTest') {
+    return `nullptr == ${str_value(Exp[0], env)}`;
+  } else if (Kind == "String") {
+    return '"' + String + '"';
+  } else if (String !== undefined) {
+    return String;
+  }
+  badFormat("value", val);
+}
+
+function str_thiscall_Exp(exp) {
+  return exp.Kind == 'Drf' ? str_value(exp.Exp[0]) + "->" : str_value(exp) + ".";
+}
+
+function stripcsu(s) {
+    return s.replace("class ", "").replace("struct ", "").replace("union ");
+}
+
+function str_call(prefix, edge, env) {
+  const {Exp, Type, PEdgeCallArguments, PEdgeCallInstance} = edge;
+  const {Kind, Type:cType, TypeFunctionArguments, TypeFunctionCSU} = Type;
+
+  if (Kind == 'Function') {
+    const params = PEdgeCallArguments ? PEdgeCallArguments.Exp : [];
+    const strParams = params.map(str_value);
+
+    let func;
+    let comment = "";
+    let assign_exp;
+    if (PEdgeCallInstance) {
+      const csu = TypeFunctionCSU.Type.Name;
+      const method = str_value(Exp[0], env);
+
+      // Heuristic to only display the csu for constructors
+      if (csu.includes(method)) {
+        func = stripcsu(csu) + "::" + method;
+      } else {
+        func = method;
+        comment = "# " + csu + "::" + method + "\n";
+      }
+
+      const {Exp: thisExp} = PEdgeCallInstance;
+      func = str_thiscall_Exp(thisExp) + func;
+    } else {
+      func = str_value(Exp[0]);
+    }
+    assign_exp = Exp[1];
+
+    let assign = "";
+    if (assign_exp) {
+      assign = str_value(assign_exp) + " := ";
+    }
+    return `${comment}${prefix} Call ${assign}${func}(${strParams.join(", ")})`;
+  }
+
+  print(JSON.stringify(edge, null, 4));
+  throw new Error("unhandled format error");
+}
+
+function str_assign(prefix, edge) {
+  const {Exp} = edge;
+  const [lhs, rhs] = Exp;
+  return `${prefix} Assign ${str_value(lhs)} := ${str_value(rhs)}`;
+}
+
+function str_loop(prefix, edge) {
+  const {BlockId: {Loop}} = edge;
+  return `${prefix} Loop ${Loop}`;
+}
+
+function str_assume(prefix, edge) {
+  const {Exp, PEdgeAssumeNonZero} = edge;
+  const cmp = PEdgeAssumeNonZero ? "" : "!";
+
+  const {Exp: aExp, Kind, OpCode} = Exp[0];
+  if (Kind == 'Binop') {
+    const [lhs, rhs] = aExp;
+    const op = opcode_name(OpCode, !PEdgeAssumeNonZero);
+    return `${prefix} Assume ${str_value(lhs)} ${op} ${str_value(rhs)}`;
+  } else if (Kind == 'Unop') {
+    return `${prefix} Assume ${cmp}${OpCode} ${str_value(aExp[0])}`;
+  } else if (Kind == 'NullTest') {
+    return `${prefix} Assume nullptr ${cmp}== ${str_value(aExp[0])}`;
+  } else if (Kind == 'Drf') {
+    return `${prefix} Assume ${cmp}${str_value(Exp[0])}`;
+  }
+
+  print(JSON.stringify(edge, null, 4));
+  throw new Error("unhandled format error");
+}
+
+function str_edge(edge, env) {
+  const {Index, Kind} = edge;
+  const [src, dst] = Index;
+  const prefix = `[${src},${dst}]`;
+
+  if (Kind == "Call")
+    return str_call(prefix, edge, env);
+  if (Kind == 'Assign')
+    return str_assign(prefix, edge);
+  if (Kind == 'Assume')
+    return str_assume(prefix, edge);
+  if (Kind == 'Loop')
+    return str_loop(prefix, edge);
+
+  print(JSON.stringify(edge, null, 4));
+  throw "unhandled edge type";
+}
+
+function str(unknown) {
+  if ("Name" in unknown) {
+    return str_Variable(unknown);
+  } else if ("Index" in unknown) {
+    // Note: Variable also has .Index, with a different meaning.
+    return str_edge(unknown);
+  } else if ("Kind" in unknown) {
+    if ("BlockId" in unknown)
+      return str_Variable(unknown);
+    return str_value(unknown);
+  } else if ("Type" in unknown) {
+    return str_Type(unknown);
+  }
+  return "unknown";
+}
+
+function jdump(x) {
+  print(JSON.stringify(x, null, 4));
+  quit(0);
+}