зеркало из https://github.com/mozilla/gecko-dev.git
881 строка
28 KiB
JavaScript
881 строка
28 KiB
JavaScript
/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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require({ version: '1.8' });
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require({ after_gcc_pass: 'cfg' });
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include('treehydra.js');
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include('util.js');
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include('gcc_util.js');
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include('gcc_print.js');
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include('unstable/adts.js');
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include('unstable/analysis.js');
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include('unstable/esp.js');
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let Zero_NonZero = {};
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include('unstable/zero_nonzero.js', Zero_NonZero);
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include('xpcom/analysis/mayreturn.js');
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function safe_location_of(t) {
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if (t === undefined)
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return UNKNOWN_LOCATION;
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return location_of(t);
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}
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MapFactory.use_injective = true;
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// Print a trace for each function analyzed
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let TRACE_FUNCTIONS = 0;
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// Trace operation of the ESP analysis, use 2 or 3 for more detail
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let TRACE_ESP = 0;
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// Trace determination of function call parameter semantics, 2 for detail
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let TRACE_CALL_SEM = 0;
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// Print time-taken stats
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let TRACE_PERF = 0;
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// Log analysis results in a special format
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let LOG_RESULTS = false;
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const WARN_ON_SET_NULL = false;
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const WARN_ON_SET_FAILURE = false;
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// Filter functions to process per CLI
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let func_filter;
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if (this.arg == undefined || this.arg == '') {
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func_filter = function(fd) true;
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} else {
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func_filter = function(fd) function_decl_name(fd) == this.arg;
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}
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function process_tree(func_decl) {
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if (!func_filter(func_decl)) return;
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// Determine outparams and return if function not relevant
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if (DECL_CONSTRUCTOR_P(func_decl)) return;
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let psem = OutparamCheck.prototype.func_param_semantics(func_decl);
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if (!psem.some(function(x) x.check)) return;
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let decl = rectify_function_decl(func_decl);
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if (decl.resultType != 'nsresult' && decl.resultType != 'PRBool' &&
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decl.resultType != 'void') {
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warning("Cannot analyze outparam usage for function with return type '" +
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decl.resultType + "'", location_of(func_decl));
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return;
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}
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let params = [ v for (v in flatten_chain(DECL_ARGUMENTS(func_decl))) ];
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let outparam_list = [];
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let psem_list = [];
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for (let i = 0; i < psem.length; ++i) {
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if (psem[i].check) {
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outparam_list.push(params[i]);
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psem_list.push(psem[i]);
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}
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}
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if (outparam_list.length == 0) return;
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// At this point we have a function we want to analyze
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let fstring = rfunc_string(decl);
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if (TRACE_FUNCTIONS) {
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print('* function ' + fstring);
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print(' ' + loc_string(location_of(func_decl)));
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}
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if (TRACE_PERF) timer_start(fstring);
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for (let i = 0; i < outparam_list.length; ++i) {
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let p = outparam_list[i];
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if (TRACE_FUNCTIONS) {
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print(" outparam " + expr_display(p) + " " + DECL_UID(p) + ' ' +
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psem_list[i].label);
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}
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}
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let cfg = function_decl_cfg(func_decl);
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let [retvar, retvars] = function() {
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let trace = 0;
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let a = new MayReturnAnalysis(cfg, trace);
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a.run();
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return [a.retvar, a.vbls];
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}();
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if (retvar == undefined && decl.resultType != 'void') throw new Error("assert");
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{
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let trace = TRACE_ESP;
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for (let i = 0; i < outparam_list.length; ++i) {
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let psem = [ psem_list[i] ];
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let outparam = [ outparam_list[i] ];
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let a = new OutparamCheck(cfg, psem, outparam, retvar, retvars, trace);
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// This is annoying, but this field is only used for logging anyway.
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a.fndecl = func_decl;
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a.run();
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a.check(decl.resultType == 'void', func_decl);
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}
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}
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if (TRACE_PERF) timer_stop(fstring);
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}
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// Outparam check analysis
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function OutparamCheck(cfg, psem_list, outparam_list, retvar, retvar_set,
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trace) {
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// We need to save the retvars so we can detect assignments through
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// their addresses passed as arguments.
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this.retvar_set = retvar_set;
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this.retvar = retvar;
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// We need both an ordered set and a lookup structure
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this.outparam_list = outparam_list
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this.outparams = create_decl_set(outparam_list);
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this.psem_list = psem_list;
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// Set up property state vars for ESP
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let psvar_list = [];
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for each (let v in outparam_list) {
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psvar_list.push(new ESP.PropVarSpec(v, true, av.NOT_WRITTEN));
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}
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for (let v in retvar_set.items()) {
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psvar_list.push(new ESP.PropVarSpec(v, v == this.retvar, ESP.TOP));
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}
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if (trace) {
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print("PS vars");
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for each (let v in this.psvar_list) {
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print(" " + expr_display(v.vbl));
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}
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}
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this.zeroNonzero = new Zero_NonZero.Zero_NonZero();
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ESP.Analysis.call(this, cfg, psvar_list, av.meet, trace);
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}
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// Abstract values for outparam check
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function AbstractValue(name, ch) {
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this.name = name;
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this.ch = ch;
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}
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AbstractValue.prototype.equals = function(v) {
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return this === v;
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}
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AbstractValue.prototype.toString = function() {
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return this.name + ' (' + this.ch + ')';
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}
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AbstractValue.prototype.toShortString = function() {
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return this.ch;
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}
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let avspec = [
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// Abstract values for outparam contents write status
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[ 'NULL', 'x' ], // is a null pointer
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[ 'NOT_WRITTEN', '-' ], // not written
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[ 'WROTE_NULL', '/' ], // had NULL written to
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[ 'WRITTEN', '+' ], // had anything written to
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// MAYBE_WRITTEN is special. "Officially", it means the same thing as
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// NOT_WRITTEN. What it really means is that an outparam was passed
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// to another function as a possible outparam (outparam type, but not
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// in last position), so if there is an error with it not being written,
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// we can give a hint about the possible outparam in the warning.
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[ 'MAYBE_WRITTEN', '?' ], // written if possible outparam is one
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];
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let av = {};
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for each (let [name, ch] in avspec) {
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av[name] = new AbstractValue(name, ch);
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}
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av.ZERO = Zero_NonZero.Lattice.ZERO;
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av.NONZERO = Zero_NonZero.Lattice.NONZERO;
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/*
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av.ZERO.negation = av.NONZERO;
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av.NONZERO.negation = av.ZERO;
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// Abstract values for int constants. We use these to figure out feasible
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// paths in the presence of GCC finally_tmp-controlled switches.
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function makeIntAV(v) {
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let key = 'int_' + v;
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if (cachedAVs.hasOwnProperty(key)) return cachedAVs[key];
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let s = "" + v;
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let ans = cachedAVs[key] = new AbstractValue(s, s);
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ans.int_val = v;
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return ans;
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}
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*/
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let cachedAVs = {};
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// Abstract values for pointers that contain a copy of an outparam
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// pointer. We use these to figure out writes to a casted copy of
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// an outparam passed to another method.
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function makeOutparamAV(v) {
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let key = 'outparam_' + DECL_UID(v);
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if (key in cachedAVs) return cachedAVs[key];
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let ans = cachedAVs[key] =
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new AbstractValue('OUTPARAM:' + expr_display(v), 'P');
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ans.outparam = v;
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return ans;
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}
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/** Return the integer value if this is an integer av, otherwise undefined. */
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av.intVal = function(v) {
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if (v.hasOwnProperty('int_val'))
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return v.int_val;
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return undefined;
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}
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/** Meet function for our abstract values. */
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av.meet = function(v1, v2) {
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// At this point we know v1 != v2.
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let values = [v1,v2]
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if (values.indexOf(av.LOCKED) != -1
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|| values.indexOf(av.UNLOCKED) != -1)
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return ESP.NOT_REACHED;
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return Zero_NonZero.meet(v1, v2)
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};
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// Outparam check analysis
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OutparamCheck.prototype = new ESP.Analysis;
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OutparamCheck.prototype.split = function(vbl, v) {
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// Can't happen for current version of ESP, but could change
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if (v != ESP.TOP) throw new Error("not implemented");
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return [ av.ZERO, av.NONZERO ];
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}
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OutparamCheck.prototype.updateEdgeState = function(e) {
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e.state.keepOnly(e.dest.keepVars);
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}
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OutparamCheck.prototype.flowState = function(isn, state) {
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switch (TREE_CODE(isn)) {
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case GIMPLE_ASSIGN:
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this.processAssign(isn, state);
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break;
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case GIMPLE_CALL:
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this.processCall(isn, isn, state);
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break;
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case GIMPLE_SWITCH:
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case GIMPLE_COND:
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// This gets handled by flowStateCond instead, has no exec effect
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break;
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default:
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this.zeroNonzero.flowState(isn, state);
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}
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}
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OutparamCheck.prototype.flowStateCond = function(isn, truth, state) {
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this.zeroNonzero.flowStateCond(isn, truth, state);
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}
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// For any outparams-specific semantics, we handle it here and then
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// return. Otherwise we delegate to the zero-nonzero analysis.
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OutparamCheck.prototype.processAssign = function(isn, state) {
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let lhs = gimple_op(isn, 0);
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let rhs = gimple_op(isn, 1);
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if (DECL_P(lhs)) {
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// Unwrap NOP_EXPR, which is semantically a copy.
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if (TREE_CODE(rhs) == NOP_EXPR) {
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rhs = rhs.operands()[0];
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}
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if (DECL_P(rhs) && this.outparams.has(rhs)) {
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// Copying an outparam pointer. We have to remember this so that
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// if it is assigned thru later, we pick up the write.
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state.assignValue(lhs, makeOutparamAV(rhs), isn);
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return;
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}
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// Cases of this switch that handle something should return from
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// the function. Anything that does not return is picked up afteward.
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switch (TREE_CODE(rhs)) {
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case INTEGER_CST:
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if (this.outparams.has(lhs)) {
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warning("assigning to outparam pointer");
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return;
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}
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break;
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case EQ_EXPR: {
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// We only care about testing outparams for NULL (and then not writing)
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let [op1, op2] = rhs.operands();
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if (DECL_P(op1) && this.outparams.has(op1) && expr_literal_int(op2) == 0) {
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state.update(function(ss) {
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let [s1, s2] = [ss, ss.copy()]; // s1 true, s2 false
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s1.assignValue(lhs, av.NONZERO, isn);
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s1.assignValue(op1, av.NULL, isn);
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s2.assignValue(lhs, av.ZERO, isn);
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return [s1, s2];
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});
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return;
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}
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}
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break;
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case CALL_EXPR:
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/* Embedded CALL_EXPRs are a 4.3 issue */
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this.processCall(rhs, isn, state, lhs);
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return;
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case INDIRECT_REF:
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// If rhs is *outparam and pointer-typed, lhs is NULL iff rhs is
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// WROTE_NULL. Required for testcase onull.cpp.
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let v = rhs.operands()[0];
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if (DECL_P(v) && this.outparams.has(v) &&
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TREE_CODE(TREE_TYPE(v)) == POINTER_TYPE) {
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state.update(function(ss) {
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let val = ss.get(v) == av.WROTE_NULL ? av.ZERO : av.NONZERO;
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ss.assignValue(lhs, val, isn);
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return [ ss ];
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});
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return;
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}
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}
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// Nothing special -- delegate
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this.zeroNonzero.processAssign(isn, state);
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return;
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}
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switch (TREE_CODE(lhs)) {
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case INDIRECT_REF:
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// Writing to an outparam. We want to try to figure out if we're
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// writing NULL.
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let e = TREE_OPERAND(lhs, 0);
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if (this.outparams.has(e)) {
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if (expr_literal_int(rhs) == 0) {
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state.assignValue(e, av.WROTE_NULL, isn);
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} else if (DECL_P(rhs)) {
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state.update(function(ss) {
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let [s1, s2] = [ss.copy(), ss]; // s1 NULL, s2 non-NULL
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s1.assignValue(e, av.WROTE_NULL, isn);
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s1.assignValue(rhs, av.ZERO, isn);
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s2.assignValue(e, av.WRITTEN, isn);
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s2.assignValue(rhs, av.NONZERO, isn);
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return [s1,s2];
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});
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} else {
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state.assignValue(e, av.WRITTEN, isn);
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}
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} else {
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// unsound -- could be writing to anything through this ptr
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}
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break;
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case COMPONENT_REF: // unsound
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case ARRAY_REF: // unsound
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case EXC_PTR_EXPR:
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case FILTER_EXPR:
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break;
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default:
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print(TREE_CODE(lhs));
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throw new Error("ni");
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}
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}
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// Handle an assignment x := test(foo) where test is a simple predicate
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OutparamCheck.prototype.processTest = function(lhs, call, val, blame, state) {
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let arg = gimple_call_arg(call, 0);
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if (DECL_P(arg)) {
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this.zeroNonzero.predicate(state, lhs, val, arg, blame);
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} else {
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state.assignValue(lhs, ESP.TOP, blame);
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}
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};
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// The big one: outparam semantics of function calls.
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OutparamCheck.prototype.processCall = function(call, blame, state, dest) {
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if (!dest)
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dest = gimple_call_lhs(call);
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let args = gimple_call_args(call);
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let callable = callable_arg_function_decl(gimple_call_fn(call));
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let psem = this.func_param_semantics(callable);
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let name = function_decl_name(callable);
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if (name == 'NS_FAILED') {
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this.processTest(dest, call, av.NONZERO, call, state);
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return;
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} else if (name == 'NS_SUCCEEDED') {
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this.processTest(dest, call, av.ZERO, call, state);
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return;
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} else if (name == '__builtin_expect') {
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// Same as an assign from arg 0 to lhs
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state.assign(dest, args[0], call);
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return;
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}
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if (TRACE_CALL_SEM) {
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print("param semantics:" + psem);
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}
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if (args.length != psem.length) {
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let ct = TREE_TYPE(callable);
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if (TREE_CODE(ct) == POINTER_TYPE) ct = TREE_TYPE(ct);
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if (args.length < psem.length || !stdarg_p(ct)) {
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// TODO Can __builtin_memcpy write to an outparam? Probably not.
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if (name != 'operator new' && name != 'operator delete' &&
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name != 'operator new []' && name != 'operator delete []' &&
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name.substr(0, 5) != '__cxa' &&
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name.substr(0, 9) != '__builtin') {
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throw Error("bad len for '" + name + "': " + args.length + ' args, ' +
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psem.length + ' params');
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}
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}
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}
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// Collect variables that are possibly written to on callee success
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let updates = [];
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for (let i = 0; i < psem.length; ++i) {
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let arg = args[i];
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// The arg could be the address of a return-value variable.
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// This means it's really the nsresult code for the call,
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// so we treat it the same as the target of an rv assignment.
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if (TREE_CODE(arg) == ADDR_EXPR) {
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let v = arg.operands()[0];
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if (DECL_P(v) && this.retvar_set.has(v)) {
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dest = v;
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}
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}
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// The arg could be a copy of an outparam. We'll unwrap to the
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// outparam if it is. The following is cheating a bit because
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// we munge states together, but it should be OK in practice.
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arg = unwrap_outparam(arg, state);
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let sem = psem[i];
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if (sem == ps.CONST) continue;
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// At this point, we know the call can write thru this param.
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// Invalidate any vars whose addresses are passed here. This
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// is distinct from the rv handling above.
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if (TREE_CODE(arg) == ADDR_EXPR) {
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let v = arg.operands()[0];
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if (DECL_P(v)) {
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state.remove(v);
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}
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}
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if (!DECL_P(arg) || !this.outparams.has(arg)) continue;
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// At this point, we may be writing to an outparam
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updates.push([arg, sem]);
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}
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if (updates.length) {
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if (dest != undefined && DECL_P(dest)) {
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// Update & stored rv. Do updates predicated on success.
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let [ succ_ret, fail_ret ] = ret_coding(callable);
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state.update(function(ss) {
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let [s1, s2] = [ss.copy(), ss]; // s1 success, s2 fail
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for each (let [vbl, sem] in updates) {
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s1.assignValue(vbl, sem.val, blame);
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s1.assignValue(dest, succ_ret, blame);
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}
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s2.assignValue(dest, fail_ret, blame);
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return [s1,s2];
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});
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} else {
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// Discarded rv. Per spec in the bug, we assume that either success
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// or failure is possible (if not, callee should return void).
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// Exceptions: Methods that return void and string mutators are
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// considered no-fail.
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state.update(function(ss) {
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for each (let [vbl, sem] in updates) {
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if (sem == ps.OUTNOFAIL || sem == ps.OUTNOFAILNOCHECK) {
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ss.assignValue(vbl, av.WRITTEN, blame);
|
|
return [ss];
|
|
} else {
|
|
let [s1, s2] = [ss.copy(), ss]; // s1 success, s2 fail
|
|
for each (let [vbl, sem] in updates) {
|
|
s1.assignValue(vbl, sem.val, blame);
|
|
}
|
|
return [s1,s2];
|
|
}
|
|
}
|
|
});
|
|
}
|
|
} else {
|
|
// no updates, just kill any destination for the rv
|
|
if (dest != undefined && DECL_P(dest)) {
|
|
state.remove(dest, blame);
|
|
}
|
|
}
|
|
};
|
|
|
|
/** Return the return value coding of the given function. This is a pair
|
|
* [ succ, fail ] giving the abstract values of the return value under
|
|
* success and failure conditions. */
|
|
function ret_coding(callable) {
|
|
let type = TREE_TYPE(callable);
|
|
if (TREE_CODE(type) == POINTER_TYPE) type = TREE_TYPE(type);
|
|
|
|
let rtname = TYPE_NAME(TREE_TYPE(type));
|
|
if (rtname && IDENTIFIER_POINTER(DECL_NAME(rtname)) == 'PRBool') {
|
|
return [ av.NONZERO, av.ZERO ];
|
|
} else {
|
|
return [ av.ZERO, av.NONZERO ];
|
|
}
|
|
}
|
|
|
|
function unwrap_outparam(arg, state) {
|
|
if (!DECL_P(arg) || state.factory.outparams.has(arg)) return arg;
|
|
|
|
let outparam;
|
|
for (let ss in state.substates.getValues()) {
|
|
let val = ss.get(arg);
|
|
if (val != undefined && val.hasOwnProperty('outparam')) {
|
|
outparam = val.outparam;
|
|
}
|
|
}
|
|
if (outparam) return outparam;
|
|
return arg;
|
|
}
|
|
|
|
// Check for errors. Must .run() analysis before calling this.
|
|
OutparamCheck.prototype.check = function(isvoid, fndecl) {
|
|
let state = this.cfg.x_exit_block_ptr.stateOut;
|
|
for (let substate in state.substates.getValues()) {
|
|
this.checkSubstate(isvoid, fndecl, substate);
|
|
}
|
|
}
|
|
|
|
OutparamCheck.prototype.checkSubstate = function(isvoid, fndecl, ss) {
|
|
if (isvoid) {
|
|
this.checkSubstateSuccess(ss);
|
|
} else {
|
|
let [succ, fail] = ret_coding(fndecl);
|
|
let rv = ss.get(this.retvar);
|
|
// We want to check if the abstract value of the rv is entirely
|
|
// contained in the success or failure condition.
|
|
if (av.meet(rv, succ) == rv) {
|
|
this.checkSubstateSuccess(ss);
|
|
} else if (av.meet(rv, fail) == rv) {
|
|
this.checkSubstateFailure(ss);
|
|
} else {
|
|
// This condition indicates a bug in outparams.js. We'll just
|
|
// warn so we don't break static analysis builds.
|
|
warning("Outparams checker cannot determine rv success/failure",
|
|
location_of(fndecl));
|
|
this.checkSubstateSuccess(ss);
|
|
this.checkSubstateFailure(ss);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* @return The return statement in the function
|
|
* that writes the return value in the given substate.
|
|
* If the function returns void, then the substate doesn't
|
|
* matter and we just look for the return. */
|
|
OutparamCheck.prototype.findReturnStmt = function(ss) {
|
|
if (this.retvar != undefined)
|
|
return ss.getBlame(this.retvar);
|
|
|
|
if (this.cfg._cached_return)
|
|
return this.cfg._cached_return;
|
|
|
|
for (let bb in cfg_bb_iterator(this.cfg)) {
|
|
for (let isn in bb_isn_iterator(bb)) {
|
|
if (isn.tree_code() == GIMPLE_RETURN) {
|
|
return this.cfg._cached_return = isn;
|
|
}
|
|
}
|
|
}
|
|
|
|
return undefined;
|
|
}
|
|
|
|
OutparamCheck.prototype.checkSubstateSuccess = function(ss) {
|
|
for (let i = 0; i < this.psem_list.length; ++i) {
|
|
let [v, psem] = [ this.outparam_list[i], this.psem_list[i] ];
|
|
if (psem == ps.INOUT) continue;
|
|
let val = ss.get(v);
|
|
if (val == av.NOT_WRITTEN) {
|
|
this.logResult('succ', 'not_written', 'error');
|
|
this.warn([this.findReturnStmt(ss), "outparam '" + expr_display(v) + "' not written on NS_SUCCEEDED(return value)"],
|
|
[v, "outparam declared here"]);
|
|
} else if (val == av.MAYBE_WRITTEN) {
|
|
this.logResult('succ', 'maybe_written', 'error');
|
|
|
|
let blameStmt = ss.getBlame(v);
|
|
let callMsg;
|
|
let callName = "";
|
|
try {
|
|
let call = TREE_CHECK(blameStmt, GIMPLE_CALL, GIMPLE_MODIFY_STMT);
|
|
let callDecl = callable_arg_function_decl(gimple_call_fn(call));
|
|
|
|
callMsg = [callDecl, "declared here"];
|
|
callName = " '" + decl_name(callDecl) + "'";
|
|
}
|
|
catch (e if e.TreeCheckError) { }
|
|
|
|
this.warn([this.findReturnStmt(ss), "outparam '" + expr_display(v) + "' not written on NS_SUCCEEDED(return value)"],
|
|
[v, "outparam declared here"],
|
|
[blameStmt, "possibly written by unannotated function call" + callName],
|
|
callMsg);
|
|
} else {
|
|
this.logResult('succ', '', 'ok');
|
|
}
|
|
}
|
|
}
|
|
|
|
OutparamCheck.prototype.checkSubstateFailure = function(ss) {
|
|
for (let i = 0; i < this.psem_list.length; ++i) {
|
|
let [v, ps] = [ this.outparam_list[i], this.psem_list[i] ];
|
|
let val = ss.get(v);
|
|
if (val == av.WRITTEN) {
|
|
this.logResult('fail', 'written', 'error');
|
|
if (WARN_ON_SET_FAILURE) {
|
|
this.warn([this.findReturnStmt(ss), "outparam '" + expr_display(v) + "' written on NS_FAILED(return value)"],
|
|
[v, "outparam declared here"],
|
|
[ss.getBlame(v), "written here"]);
|
|
}
|
|
} else if (val == av.WROTE_NULL) {
|
|
this.logResult('fail', 'wrote_null', 'warning');
|
|
if (WARN_ON_SET_NULL) {
|
|
this.warn([this.findReturnStmt(ss), "NULL written to outparam '" + expr_display(v) + "' on NS_FAILED(return value)"],
|
|
[v, "outparam declared here"],
|
|
[ss.getBlame(v), "written here"]);
|
|
}
|
|
} else {
|
|
this.logResult('fail', '', 'ok');
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Generate a warning from one or more tuples [treeforloc, message]
|
|
*/
|
|
OutparamCheck.prototype.warn = function(arg0) {
|
|
let loc = safe_location_of(arg0[0]);
|
|
let msg = arg0[1];
|
|
|
|
for (let i = 1; i < arguments.length; ++i) {
|
|
if (arguments[i] === undefined) continue;
|
|
let [atree, amsg] = arguments[i];
|
|
msg += "\n" + loc_string(safe_location_of(atree)) + ": " + amsg;
|
|
}
|
|
warning(msg, loc);
|
|
}
|
|
|
|
OutparamCheck.prototype.logResult = function(rv, msg, kind) {
|
|
if (LOG_RESULTS) {
|
|
let s = [ '"' + x + '"' for each (x in [ loc_string(location_of(this.fndecl)), function_decl_name(this.fndecl), rv, msg, kind ]) ].join(', ');
|
|
print(":LR: (" + s + ")");
|
|
}
|
|
}
|
|
|
|
// Parameter Semantics values -- indicates whether a parameter is
|
|
// an outparam.
|
|
// label Used for debugging output
|
|
// val Abstract value (state) that holds on an argument after
|
|
// a call
|
|
// check True if parameters with this semantics should be
|
|
// checked by this analysis
|
|
let ps = {
|
|
OUTNOFAIL: { label: 'out-no-fail', val: av.WRITTEN, check: true },
|
|
// Special value for receiver of strings methods. Callers should
|
|
// consider this to be an outparam (i.e., it modifies the string),
|
|
// but we don't want to check the method itself.
|
|
OUTNOFAILNOCHECK: { label: 'out-no-fail-no-check' },
|
|
OUT: { label: 'out', val: av.WRITTEN, check: true },
|
|
INOUT: { label: 'inout', val: av.WRITTEN, check: true },
|
|
MAYBE: { label: 'maybe', val: av.MAYBE_WRITTEN}, // maybe out
|
|
CONST: { label: 'const' } // i.e. not out
|
|
};
|
|
|
|
// Return the param semantics of a FUNCTION_DECL or VAR_DECL representing
|
|
// a function pointer. The result is a pair [ ann, sems ].
|
|
OutparamCheck.prototype.func_param_semantics = function(callable) {
|
|
let ftype = TREE_TYPE(callable);
|
|
if (TREE_CODE(ftype) == POINTER_TYPE) ftype = TREE_TYPE(ftype);
|
|
// What failure semantics to use for outparams
|
|
let rtype = TREE_TYPE(ftype);
|
|
let nofail = TREE_CODE(rtype) == VOID_TYPE;
|
|
// Whether to guess outparams by type
|
|
let guess = type_string(rtype) == 'nsresult';
|
|
|
|
// Set up param lists for analysis
|
|
let params; // param decls, if available
|
|
let types; // param types
|
|
let string_mutator = false;
|
|
if (TREE_CODE(callable) == FUNCTION_DECL) {
|
|
params = [ p for (p in function_decl_params(callable)) ];
|
|
types = [ TREE_TYPE(p) for each (p in params) ];
|
|
string_mutator = is_string_mutator(callable);
|
|
} else {
|
|
types = [ p for (p in function_type_args(ftype))
|
|
if (TREE_CODE(p) != VOID_TYPE) ];
|
|
}
|
|
|
|
// Analyze params
|
|
let ans = [];
|
|
for (let i = 0; i < types.length; ++i) {
|
|
let sem;
|
|
if (i == 0 && string_mutator) {
|
|
// Special case: string mutator receiver is an no-fail outparams
|
|
// but not checkable
|
|
sem = ps.OUTNOFAILNOCHECK;
|
|
} else {
|
|
if (params) sem = decode_attr(DECL_ATTRIBUTES(params[i]));
|
|
if (TRACE_CALL_SEM >= 2) print("param " + i + ": annotated " + sem);
|
|
if (sem == undefined) {
|
|
sem = decode_attr(TYPE_ATTRIBUTES(types[i]));
|
|
if (TRACE_CALL_SEM >= 2) print("type " + i + ": annotated " + sem);
|
|
if (sem == undefined) {
|
|
if (guess && type_is_outparam(types[i])) {
|
|
// Params other than last are guessed as MAYBE
|
|
sem = i < types.length - 1 ? ps.MAYBE : ps.OUT;
|
|
} else {
|
|
sem = ps.CONST;
|
|
}
|
|
}
|
|
}
|
|
if (sem == ps.OUT && nofail) sem = ps.OUTNOFAIL;
|
|
}
|
|
if (sem == undefined) throw new Error("assert");
|
|
ans.push(sem);
|
|
}
|
|
return ans;
|
|
}
|
|
|
|
/* Decode parameter semantics GCC attributes.
|
|
* @param attrs GCC attributes of a parameter. E.g., TYPE_ATTRIBUTES
|
|
* or DECL_ATTRIBUTES of an item
|
|
* @return The parameter semantics value defined by the attributes,
|
|
* or undefined if no such attributes were present. */
|
|
function decode_attr(attrs) {
|
|
// Note: we're not checking for conflicts, we just take the first
|
|
// one we find.
|
|
for each (let attr in rectify_attributes(attrs)) {
|
|
if (attr.name == 'user') {
|
|
for each (let arg in attr.args) {
|
|
if (arg == 'NS_outparam') {
|
|
return ps.OUT;
|
|
} else if (arg == 'NS_inoutparam') {
|
|
return ps.INOUT;
|
|
} else if (arg == 'NS_inparam') {
|
|
return ps.CONST;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return undefined;
|
|
}
|
|
|
|
/* @return true if the given type appears to be an outparam
|
|
* type based on the type alone (i.e., not considering
|
|
* attributes. */
|
|
function type_is_outparam(type) {
|
|
switch (TREE_CODE(type)) {
|
|
case POINTER_TYPE:
|
|
return pointer_type_is_outparam(TREE_TYPE(type));
|
|
case REFERENCE_TYPE:
|
|
let rt = TREE_TYPE(type);
|
|
return !TYPE_READONLY(rt) && is_string_type(rt);
|
|
default:
|
|
// Note: This is unsound for UNION_TYPE, because the union could
|
|
// contain a pointer.
|
|
return false;
|
|
}
|
|
}
|
|
|
|
/* Helper for type_is_outparam.
|
|
* @return true if 'pt *' looks like an outparam type. */
|
|
function pointer_type_is_outparam(pt) {
|
|
if (TYPE_READONLY(pt)) return false;
|
|
|
|
switch (TREE_CODE(pt)) {
|
|
case POINTER_TYPE:
|
|
case ARRAY_TYPE: {
|
|
// Look for void **, nsIFoo **, char **, PRUnichar **
|
|
let ppt = TREE_TYPE(pt);
|
|
let tname = TYPE_NAME(ppt);
|
|
if (tname == undefined) return false;
|
|
let name = decl_name_string(tname);
|
|
return name == 'void' || name == 'char' || name == 'PRUnichar' ||
|
|
name.substr(0, 3) == 'nsI';
|
|
}
|
|
case INTEGER_TYPE: {
|
|
// char * and PRUnichar * are probably strings, otherwise guess
|
|
// it is an integer outparam.
|
|
let name = decl_name_string(TYPE_NAME(pt));
|
|
return name != 'char' && name != 'PRUnichar';
|
|
}
|
|
case ENUMERAL_TYPE:
|
|
case REAL_TYPE:
|
|
case UNION_TYPE:
|
|
case BOOLEAN_TYPE:
|
|
return true;
|
|
case RECORD_TYPE:
|
|
// TODO: should we consider field writes?
|
|
return false;
|
|
case FUNCTION_TYPE:
|
|
case VOID_TYPE:
|
|
return false;
|
|
default:
|
|
throw new Error("can't guess if a pointer to this type is an outparam: " +
|
|
TREE_CODE(pt) + ': ' + type_string(pt));
|
|
}
|
|
}
|
|
|
|
// Map type name to boolean as to whether it is a string.
|
|
let cached_string_types = MapFactory.create_map(
|
|
function (x, y) x == y,
|
|
function (x) x,
|
|
function (t) t,
|
|
function (t) t);
|
|
|
|
// Base string types. Others will be found by searching the inheritance
|
|
// graph.
|
|
|
|
cached_string_types.put('nsAString', true);
|
|
cached_string_types.put('nsACString', true);
|
|
cached_string_types.put('nsAString_internal', true);
|
|
cached_string_types.put('nsACString_internal', true);
|
|
|
|
// Return true if the given type represents a Mozilla string type.
|
|
// The binfo arg is the binfo to use for further iteration. This is
|
|
// for internal use only, users of this function should pass only
|
|
// one arg.
|
|
function is_string_type(type, binfo) {
|
|
if (TREE_CODE(type) != RECORD_TYPE) return false;
|
|
//print(">>>IST " + type_string(type));
|
|
let name = decl_name_string(TYPE_NAME(type));
|
|
let ans = cached_string_types.get(name);
|
|
if (ans != undefined) return ans;
|
|
|
|
ans = false;
|
|
binfo = binfo != undefined ? binfo : TYPE_BINFO(type);
|
|
if (binfo != undefined) {
|
|
for each (let base in VEC_iterate(BINFO_BASE_BINFOS(binfo))) {
|
|
let parent_ans = is_string_type(BINFO_TYPE(base), base);
|
|
if (parent_ans) {
|
|
ans = true;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
cached_string_types.put(name, ans);
|
|
//print("<<<IST " + type_string(type) + ' ' + ans);
|
|
return ans;
|
|
}
|
|
|
|
function is_string_ptr_type(type) {
|
|
return TREE_CODE(type) == POINTER_TYPE && is_string_type(TREE_TYPE(type));
|
|
}
|
|
|
|
// Return true if the given function is a mutator method of a Mozilla
|
|
// string type.
|
|
function is_string_mutator(fndecl) {
|
|
let first_param = function() {
|
|
for (let p in function_decl_params(fndecl)) {
|
|
return p;
|
|
}
|
|
return undefined;
|
|
}();
|
|
|
|
return first_param != undefined &&
|
|
decl_name_string(first_param) == 'this' &&
|
|
is_string_ptr_type(TREE_TYPE(first_param)) &&
|
|
!TYPE_READONLY(TREE_TYPE(TREE_TYPE(first_param)));
|
|
}
|
|
|