Elf interface for new unwinder.
This cl includes the code to read arm unwind information from a shared
library.
Bug: 23762183
Test: Passes all unit tests. I can dump the arm unwind information
Test: for an arm shared library.
Change-Id: I43501ea2eab843b81de8bd5128401dd1971af8d3
diff --git a/libunwindstack/ElfInterfaceArm.h b/libunwindstack/ElfInterfaceArm.h
new file mode 100644
index 0000000..ece694f
--- /dev/null
+++ b/libunwindstack/ElfInterfaceArm.h
@@ -0,0 +1,90 @@
+/*
+ * Copyright (C) 2016 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.
+ */
+
+#ifndef _LIBUNWINDSTACK_ELF_INTERFACE_ARM_H
+#define _LIBUNWINDSTACK_ELF_INTERFACE_ARM_H
+
+#include <elf.h>
+#include <stdint.h>
+
+#include <iterator>
+#include <unordered_map>
+
+#include "ElfInterface.h"
+#include "Memory.h"
+
+class ElfInterfaceArm : public ElfInterface32 {
+ public:
+ ElfInterfaceArm(Memory* memory) : ElfInterface32(memory) {}
+ virtual ~ElfInterfaceArm() = default;
+
+ class iterator : public std::iterator<std::bidirectional_iterator_tag, uint32_t> {
+ public:
+ iterator(ElfInterfaceArm* interface, size_t index) : interface_(interface), index_(index) { }
+
+ iterator& operator++() { index_++; return *this; }
+ iterator& operator++(int increment) { index_ += increment; return *this; }
+ iterator& operator--() { index_--; return *this; }
+ iterator& operator--(int decrement) { index_ -= decrement; return *this; }
+
+ bool operator==(const iterator& rhs) { return this->index_ == rhs.index_; }
+ bool operator!=(const iterator& rhs) { return this->index_ != rhs.index_; }
+
+ uint32_t operator*() {
+ uint32_t addr = interface_->addrs_[index_];
+ if (addr == 0) {
+ if (!interface_->GetPrel31Addr(interface_->start_offset_ + index_ * 8, &addr)) {
+ return 0;
+ }
+ interface_->addrs_[index_] = addr;
+ }
+ return addr;
+ }
+
+ private:
+ ElfInterfaceArm* interface_ = nullptr;
+ size_t index_ = 0;
+ };
+
+ iterator begin() { return iterator(this, 0); }
+ iterator end() { return iterator(this, total_entries_); }
+
+ bool GetPrel31Addr(uint32_t offset, uint32_t* addr);
+
+ bool FindEntry(uint32_t pc, uint64_t* entry_offset);
+
+ bool HandleType(uint64_t offset, uint32_t type) override;
+
+ bool Step(uint64_t pc, Regs* regs, Memory* process_memory) override;
+
+ bool StepExidx(uint64_t pc, Regs* regs, Memory* process_memory);
+
+ uint64_t start_offset() { return start_offset_; }
+
+ void set_start_offset(uint64_t start_offset) { start_offset_ = start_offset; }
+
+ size_t total_entries() { return total_entries_; }
+
+ void set_total_entries(size_t total_entries) { total_entries_ = total_entries; }
+
+ private:
+ uint64_t start_offset_ = 0;
+ size_t total_entries_ = 0;
+
+ std::unordered_map<size_t, uint32_t> addrs_;
+};
+
+#endif // _LIBUNWINDSTACK_ELF_INTERFACE_ARM_H