1 files changed, 90 insertions, 0 deletions
diff --git a/libdex/DexCatch.c b/libdex/DexCatch.c
new file mode 100644
index 0000000..ed97e87
--- /dev/null
+++ b/libdex/DexCatch.c
@@ -0,0 +1,90 @@
+/*
+ * 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));
+}