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/* 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,
/* -*- indent-tabs-mode: nil; js-indent-level: 4 -*- */
"use strict";
loadRelativeToScript('callgraph.js');
var options = parse_options([
{
name: '--verbose',
type: 'bool'
},
{
name: '--function',
type: 'string'
},
{
name: 'typeInfo_filename',
type: 'string',
default: "typeInfo.txt"
},
{
name: 'callgraphOut_filename',
type: 'string',
default: "rawcalls.txt"
},
{
name: 'batch',
default: 1,
type: 'number'
},
{
name: 'numBatches',
default: 1,
type: 'number'
},
]);
var origOut = os.file.redirect(options.callgraphOut_filename);
var memoized = new Map();
var unmangled2id = new Set();
// Insert a string into the name table and return the ID. Do not use for
// functions, which must be handled specially.
function getId(name)
{
let id = memoized.get(name);
if (id !== undefined)
return id;
id = memoized.size + 1;
memoized.set(name, id);
print(`#${id} ${name}`);
return id;
}
// Split a function into mangled and unmangled parts and return the ID for the
// function.
function functionId(name)
{
const [mangled, unmangled] = splitFunction(name);
const id = getId(mangled);
// Only produce a mangled -> unmangled mapping once, unless there are
// multiple unmangled names for the same mangled name.
if (unmangled2id.has(unmangled))
return id;
print(`= ${id} ${unmangled}`);
unmangled2id.add(unmangled);
return id;
}
var lastline;
function printOnce(line)
{
if (line != lastline) {
print(line);
lastline = line;
}
}
// Returns a table mapping function name to lists of
// [annotation-name, annotation-value] pairs:
// { function-name => [ [annotation-name, annotation-value] ] }
//
// Note that sixgill will only store certain attributes (annotation-names), so
// this won't be *all* the attributes in the source, just the ones that sixgill
// watches for.
function getAllAttributes(body)
{
var all_annotations = {};
for (var v of (body.DefineVariable || [])) {
if (v.Variable.Kind != 'Func')
continue;
var name = v.Variable.Name[0];
var annotations = all_annotations[name] = [];
for (var ann of (v.Type.Annotation || [])) {
annotations.push(ann.Name);
}
}
return all_annotations;
}
// Get just the annotations understood by the hazard analysis.
function getAnnotations(functionName, body) {
var tags = new Set();
var attributes = getAllAttributes(body);
if (functionName in attributes) {
for (var [ annName, annValue ] of attributes[functionName]) {
if (annName == 'annotate')
tags.add(annValue);
}
}
return tags;
}
// Scan through a function body, pulling out all annotations and calls and
// recording them in callgraph.txt.
function processBody(functionName, body, functionBodies)
{
if (!('PEdge' in body))
return;
for (var tag of getAnnotations(functionName, body).values()) {
const id = functionId(functionName);
print(`T ${id} ${tag}`);
if (tag == "Calls JSNatives")
printOnce(`D ${id} ${functionId("(js-code)")}`);
}
// Set of all callees that have been output so far, in order to suppress
// repeated callgraph edges from being recorded. This uses a Map from
// callees to limit sets, because we don't want a limited edge to prevent
// an unlimited edge from being recorded later. (So an edge will be skipped
// if it exists and is at least as limited as the previously seen edge.)
//
// Limit sets are implemented as integers interpreted as bitfields.
//
var seen = new Map();
lastline = null;
for (var edge of body.PEdge) {
if (edge.Kind != "Call")
continue;
// The attrs (eg ATTR_GC_SUPPRESSED) are determined by whatever RAII
// scopes might be active, which have been computed previously for all
// points in the body.
const scopeAttrs = body.attrs[edge.Index[0]] | 0;
for (const { callee, attrs } of getCallees(body, edge, scopeAttrs, functionBodies)) {
// Some function names will be synthesized by manually constructing
// their names. Verify that we managed to synthesize an existing function.
// This cannot be done later with either the callees or callers tables,
// because the function may be an otherwise uncalled leaf.
if (attrs & ATTR_SYNTHETIC) {
assertFunctionExists(callee.name);
}
// Individual callees may have additional attrs. The only such
// bit currently is that nsISupports.{AddRef,Release} are assumed
// to never GC.
let prologue = attrs ? `/${attrs} ` : "";
prologue += functionId(functionName) + " ";
if (callee.kind == 'direct') {
const prev_attrs = seen.has(callee.name) ? seen.get(callee.name) : ATTRS_UNVISITED;
if (prev_attrs & ~attrs) {
// Only output an edge if it loosens a limit.
seen.set(callee.name, prev_attrs & attrs);
printOnce("D " + prologue + functionId(callee.name));
}
} else if (callee.kind == 'field') {
var { csu, field, isVirtual } = callee;
const tag = isVirtual ? 'V' : 'F';
const fullfield = `${csu}.${field}`;
printOnce(`${tag} ${prologue}${getId(fullfield)} CLASS ${csu} FIELD ${field}`);
} else if (callee.kind == 'resolved-field') {
// Fully-resolved field (virtual method) call. Record the
// callgraph edges. Do not consider attrs, since they are local
// to this callsite and we are writing out a global record
// here.
//
// Any field call that does *not* have an R entry must be
// assumed to call anything.
var { csu, field, callees } = callee;
var fullFieldName = csu + "." + field;
if (!virtualResolutionsSeen.has(fullFieldName)) {
virtualResolutionsSeen.add(fullFieldName);
for (var target of callees)
printOnce("R " + getId(fullFieldName) + " " + functionId(target.name));
}
} else if (callee.kind == 'indirect') {
printOnce("I " + prologue + "VARIABLE " + callee.variable);
} else if (callee.kind == 'unknown') {
printOnce("I " + prologue + "VARIABLE UNKNOWN");
} else {
printErr("invalid " + callee.kind + " callee");
debugger;
}
}
}
}
// Reserve IDs for special function names.
// represents anything that can run JS
assert(ID.jscode == functionId("(js-code)"));
// function pointers will get an edge to this in loadCallgraph.js; only the ID
// reservation is present in callgraph.txt
assert(ID.anyfunc == functionId("(any-function)"));
// same as above, but for fields annotated to never GC
assert(ID.nogcfunc == functionId("(nogc-function)"));
// garbage collection
assert(ID.gc == functionId("(GC)"));
var typeInfo = loadTypeInfo(options.typeInfo_filename);
loadTypes("src_comp.xdb");
// Arbitrary JS code must always be assumed to GC. In real code, there would
// always be a path anyway through some arbitrary JSNative, but this route will be shorter.
print(`D ${ID.jscode} ${ID.gc}`);
// An unknown function is assumed to GC.
print(`D ${ID.anyfunc} ${ID.gc}`);
// Output call edges for all virtual methods defined anywhere, from
// Class.methodname to what a (dynamic) instance of Class would run when
// methodname was called (either Class::methodname() if defined, or some
// Base::methodname() for inherited method definitions).
for (const [fieldkey, methods] of virtualDefinitions) {
const caller = getId(fieldkey);
for (const name of methods) {
const callee = functionId(name);
printOnce(`D ${caller} ${callee}`);
}
}
// Output call edges from C.methodname -> S.methodname for all subclasses S of
// class C. This is for when you are calling methodname on a pointer/ref of
// dynamic type C, so that the callgraph contains calls to all descendant
// subclasses' implementations.
for (const [csu, methods] of virtualDeclarations) {
for (const {field, dtor} of methods) {
const caller = getId(fieldKey(csu, field));
if (virtualCanRunJS(csu, field.Name[0]))
printOnce(`D ${caller} ${functionId("(js-code)")}`);
if (dtor)
printOnce(`D ${caller} ${functionId(dtor)}`);
if (!subclasses.has(csu))
continue;
for (const sub of subclasses.get(csu)) {
printOnce(`D ${caller} ${getId(fieldKey(sub, field))}`);
}
}
}
var xdb = xdbLibrary();
xdb.open("src_body.xdb");
if (options.verbose) {
printErr("Finished loading data structures");
}
var minStream = xdb.min_data_stream();
var maxStream = xdb.max_data_stream();
if (options.function) {
var index = xdb.lookup_key(options.function);
if (!index) {
printErr("Function not found");
quit(1);
}
minStream = maxStream = index;
}
function assertFunctionExists(name) {
var data = xdb.read_entry(name);
assert(data.contents != 0, `synthetic function '${name}' not found!`);
}
function process(functionName, functionBodies)
{
for (var body of functionBodies)
body.attrs = [];
for (var body of functionBodies) {
for (var [pbody, id, attrs] of allRAIIGuardedCallPoints(typeInfo, functionBodies, body, isLimitConstructor)) {
pbody.attrs[id] = attrs;
}
}
if (options.function) {
debugger;
}
for (var body of functionBodies) {
processBody(functionName, body, functionBodies);
}
// Not strictly necessary, but add an edge from the synthetic "(js-code)"
// to RunScript to allow better stacks than just randomly selecting a
// JSNative to blame things on.
if (functionName.includes("js::RunScript"))
print(`D ${functionId("(js-code)")} ${functionId(functionName)}`);
// GCC generates multiple constructors and destructors ("in-charge" and
// "not-in-charge") to handle virtual base classes. They are normally
// identical, and it appears that GCC does some magic to alias them to the
// same thing. But this aliasing is not visible to the analysis. So we'll
// add a dummy call edge from "foo" -> "foo *INTERNAL* ", since only "foo"
// will show up as called but only "foo *INTERNAL* " will be emitted in the
// case where the constructors are identical.
//
// This is slightly conservative in the case where they are *not*
// identical, but that should be rare enough that we don't care.
var markerPos = functionName.indexOf(internalMarker);
if (markerPos > 0) {
var inChargeXTor = functionName.replace(internalMarker, "");
printOnce("D " + functionId(inChargeXTor) + " " + functionId(functionName));
}
const [ mangled, unmangled ] = splitFunction(functionName);
// different kinds of constructors/destructors are:
// C1 # complete object constructor
// C2 # base object constructor
// C3 # complete object allocating constructor
// D0 # deleting destructor
// D1 # complete object destructor
// D2 # base object destructor
//
// In actual practice, I have observed C4 and D4 xtors generated by gcc
// 4.9.3 (but not 4.7.3). The gcc source code says:
//
// /* This is the old-style "[unified]" constructor.
// In some cases, we may emit this function and call
// it from the clones in order to share code and save space. */
//
// Unfortunately, that "call... from the clones" does not seem to appear in
// the CFG we get from GCC. So if we see a C4 constructor or D4 destructor,
// inject an edge to it from C1, C2, and C3 (or D1, D2, and D3). (Note that
// C3 isn't even used in current GCC, but add the edge anyway just in
// case.)
//
// from gcc/cp/mangle.c:
//
// <special-name> ::= D0 # deleting (in-charge) destructor
// ::= D1 # complete object (in-charge) destructor
// ::= D2 # base object (not-in-charge) destructor
// <special-name> ::= C1 # complete object constructor
// ::= C2 # base object constructor
// ::= C3 # complete object allocating constructor
//
// Currently, allocating constructors are never used.
//
if (functionName.indexOf("C4") != -1) {
// E terminates the method name (and precedes the method parameters).
// If eg "C4E" shows up in the mangled name for another reason, this
// will create bogus edges in the callgraph. But it will affect little
// and is somewhat difficult to avoid, so we will live with it.
//
// Another possibility! A templatized constructor will contain C4I...E
// for template arguments.
//
for (let [synthetic, variant, desc] of [
['C4E', 'C1E', 'complete_ctor'],
['C4E', 'C2E', 'base_ctor'],
['C4E', 'C3E', 'complete_alloc_ctor'],
['C4I', 'C1I', 'complete_ctor'],
['C4I', 'C2I', 'base_ctor'],
['C4I', 'C3I', 'complete_alloc_ctor']])
{
if (mangled.indexOf(synthetic) == -1)
continue;
let variant_mangled = mangled.replace(synthetic, variant);
let variant_full = `${variant_mangled}$${unmangled} [[${desc}]]`;
printOnce("D " + functionId(variant_full) + " " + functionId(functionName));
}
}
// For destructors:
//
// I've never seen D4Ev() + D4Ev(int32), only one or the other. So
// for a D4Ev of any sort, create:
//
// D0() -> D1() # deleting destructor calls complete destructor, then deletes
// D1() -> D2() # complete destructor calls base destructor, then destroys virtual bases
// D2() -> D4(?) # base destructor might be aliased to unified destructor
// # use whichever one is defined, in-charge or not.
// # ('?') means either () or (int32).
//
// Note that this doesn't actually make sense -- D0 and D1 should be
// in-charge, but gcc doesn't seem to give them the in-charge parameter?!
//
if (functionName.indexOf("D4Ev") != -1 && functionName.indexOf("::~") != -1) {
const not_in_charge_dtor = functionName.replace("(int32)", "()");
const D0 = not_in_charge_dtor.replace("D4Ev", "D0Ev") + " [[deleting_dtor]]";
const D1 = not_in_charge_dtor.replace("D4Ev", "D1Ev") + " [[complete_dtor]]";
const D2 = not_in_charge_dtor.replace("D4Ev", "D2Ev") + " [[base_dtor]]";
printOnce("D " + functionId(D0) + " " + functionId(D1));
printOnce("D " + functionId(D1) + " " + functionId(D2));
printOnce("D " + functionId(D2) + " " + functionId(functionName));
}
if (isJSNative(mangled))
printOnce(`D ${functionId("(js-code)")} ${functionId(functionName)}`);
}
var start = batchStart(options.batch, options.numBatches, minStream, maxStream);
var end = batchLast(options.batch, options.numBatches, minStream, maxStream);
for (var nameIndex = start; nameIndex <= end; nameIndex++) {
var name = xdb.read_key(nameIndex);
var data = xdb.read_entry(name);
process(name.readString(), JSON.parse(data.readString()));
xdb.free_string(name);
xdb.free_string(data);
}
os.file.close(os.file.redirect(origOut));