Aart Bik | 1a65052 | 2015-07-08 21:20:41 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2008 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | /* |
| 18 | * Functions for dealing with try-catch info. |
| 19 | */ |
| 20 | |
| 21 | #include "DexCatch.h" |
| 22 | |
| 23 | /* Get the first handler offset for the given DexCode. |
| 24 | * It's not 0 because the handlers list is prefixed with its size |
| 25 | * (in entries) as a uleb128. */ |
| 26 | u4 dexGetFirstHandlerOffset(const DexCode* pCode) { |
| 27 | if (pCode->triesSize == 0) { |
| 28 | return 0; |
| 29 | } |
| 30 | |
| 31 | const u1* baseData = dexGetCatchHandlerData(pCode); |
| 32 | const u1* data = baseData; |
| 33 | |
| 34 | readUnsignedLeb128(&data); |
| 35 | |
| 36 | return data - baseData; |
| 37 | } |
| 38 | |
| 39 | /* Get count of handler lists for the given DexCode. */ |
| 40 | u4 dexGetHandlersSize(const DexCode* pCode) { |
| 41 | if (pCode->triesSize == 0) { |
| 42 | return 0; |
| 43 | } |
| 44 | |
| 45 | const u1* data = dexGetCatchHandlerData(pCode); |
| 46 | |
| 47 | return readUnsignedLeb128(&data); |
| 48 | } |
| 49 | |
| 50 | /* Helper for dexFindCatchHandlerOffset(), which does an actual search |
| 51 | * in the tries table. Returns -1 if there is no applicable handler. */ |
| 52 | int dexFindCatchHandlerOffset0(u2 triesSize, const DexTry* pTries, |
| 53 | u4 address) { |
| 54 | // Note: Signed type is important for max and min. |
| 55 | int min = 0; |
| 56 | int max = triesSize - 1; |
| 57 | |
| 58 | while (max >= min) { |
| 59 | int guess = (min + max) >> 1; |
| 60 | const DexTry* pTry = &pTries[guess]; |
| 61 | u4 start = pTry->startAddr; |
| 62 | |
| 63 | if (address < start) { |
| 64 | max = guess - 1; |
| 65 | continue; |
| 66 | } |
| 67 | |
| 68 | u4 end = start + pTry->insnCount; |
| 69 | |
| 70 | if (address >= end) { |
| 71 | min = guess + 1; |
| 72 | continue; |
| 73 | } |
| 74 | |
| 75 | // We have a winner! |
| 76 | return (int) pTry->handlerOff; |
| 77 | } |
| 78 | |
| 79 | // No match. |
| 80 | return -1; |
| 81 | } |
| 82 | |
| 83 | /* Get the handler offset just past the end of the one just iterated over. |
| 84 | * This ends the iteration if it wasn't already. */ |
| 85 | u4 dexCatchIteratorGetEndOffset(DexCatchIterator* pIterator, |
| 86 | const DexCode* pCode) { |
| 87 | while (dexCatchIteratorNext(pIterator) != NULL) /* empty */ ; |
| 88 | |
| 89 | return (u4) (pIterator->pEncodedData - dexGetCatchHandlerData(pCode)); |
| 90 | } |