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/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* Functions for dealing with try-catch info.
*/
#include "DexCatch.h"
/* Get the first handler offset for the given DexCode.
* It's not 0 because the handlers list is prefixed with its size
* (in entries) as a uleb128. */
u4 dexGetFirstHandlerOffset(const DexCode* pCode) {
if (pCode->triesSize == 0) {
return 0;
}
const u1* baseData = dexGetCatchHandlerData(pCode);
const u1* data = baseData;
readUnsignedLeb128(&data);
return data - baseData;
}
/* Get count of handler lists for the given DexCode. */
u4 dexGetHandlersSize(const DexCode* pCode) {
if (pCode->triesSize == 0) {
return 0;
}
const u1* data = dexGetCatchHandlerData(pCode);
return readUnsignedLeb128(&data);
}
/* Helper for dexFindCatchHandlerOffset(), which does an actual search
* in the tries table. Returns -1 if there is no applicable handler. */
int dexFindCatchHandlerOffset0(u2 triesSize, const DexTry* pTries,
u4 address) {
// Note: Signed type is important for max and min.
int min = 0;
int max = triesSize - 1;
while (max >= min) {
int guess = (min + max) >> 1;
const DexTry* pTry = &pTries[guess];
u4 start = pTry->startAddr;
if (address < start) {
max = guess - 1;
continue;
}
u4 end = start + pTry->insnCount;
if (address >= end) {
min = guess + 1;
continue;
}
// We have a winner!
return (int) pTry->handlerOff;
}
// No match.
return -1;
}
/* Get the handler offset just past the end of the one just iterated over.
* This ends the iteration if it wasn't already. */
u4 dexCatchIteratorGetEndOffset(DexCatchIterator* pIterator,
const DexCode* pCode) {
while (dexCatchIteratorNext(pIterator) != NULL) /* empty */ ;
return (u4) (pIterator->pEncodedData - dexGetCatchHandlerData(pCode));
}