The Tor Browser / file comparison
comparison: xpcom/analysis/mayreturn.js
xpcom/analysis/mayreturn.js
- changeset 0
- 6474c204b198
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| -1:000000000000 | 0:78cb0129a6c3 |
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| 1 /* This Source Code Form is subject to the terms of the Mozilla Public | |
| 2 * License, v. 2.0. If a copy of the MPL was not distributed with this | |
| 3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 4 | |
| 5 /* May-return analysis. | |
| 6 * This makes sense only for functions that return a value. The analysis | |
| 7 * determines the set of variables that may transitively reach the return | |
| 8 * statement. */ | |
| 9 | |
| 10 function MayReturnAnalysis() { | |
| 11 BackwardAnalysis.apply(this, arguments); | |
| 12 // May-return variables. We collect them all here. | |
| 13 this.vbls = create_decl_set(); | |
| 14 // The return value variable itself | |
| 15 this.retvar = undefined; | |
| 16 } | |
| 17 | |
| 18 MayReturnAnalysis.prototype = new BackwardAnalysis; | |
| 19 | |
| 20 MayReturnAnalysis.prototype.flowState = function(isn, state) { | |
| 21 if (TREE_CODE(isn) == GIMPLE_RETURN) { | |
| 22 let v = return_expr(isn); | |
| 23 if (!v) | |
| 24 return; | |
| 25 if (v.tree_code() == RESULT_DECL) // only an issue with 4.3 | |
| 26 throw new Error("Weird case hit"); | |
| 27 this.vbls.add(v); | |
| 28 state.add(v); | |
| 29 this.retvar = v; | |
| 30 } else if (TREE_CODE(isn) == GIMPLE_ASSIGN) { | |
| 31 let lhs = gimple_op(isn, 0); | |
| 32 let rhs = gimple_op(isn, 1); | |
| 33 if (DECL_P(rhs) && DECL_P(lhs) && state.has(lhs)) { | |
| 34 this.vbls.add(rhs); | |
| 35 state.add(rhs); | |
| 36 } | |
| 37 | |
| 38 for (let e in isn_defs(isn, 'strong')) { | |
| 39 if (DECL_P(e)) { | |
| 40 state.remove(e); | |
| 41 } | |
| 42 } | |
| 43 } | |
| 44 }; |
