New version of unwinder.

Bug: 23762183

Test: All unit tests pass.
Change-Id: I0ac69e55af56e1142c0a1ee3715cdc48f2ed3ec3
diff --git a/libunwindstack/ArmExidx.cpp b/libunwindstack/ArmExidx.cpp
new file mode 100644
index 0000000..3b78918
--- /dev/null
+++ b/libunwindstack/ArmExidx.cpp
@@ -0,0 +1,680 @@
+/*
+ * 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.
+ */
+
+#include <assert.h>
+#include <stdint.h>
+
+#include <deque>
+#include <string>
+
+#include <android-base/stringprintf.h>
+
+#include "ArmExidx.h"
+#include "Log.h"
+#include "Machine.h"
+
+void ArmExidx::LogRawData() {
+  std::string log_str("Raw Data:");
+  for (const uint8_t data : data_) {
+    log_str += android::base::StringPrintf(" 0x%02x", data);
+  }
+  log(log_indent_, log_str.c_str());
+}
+
+bool ArmExidx::ExtractEntryData(uint32_t entry_offset) {
+  data_.clear();
+  status_ = ARM_STATUS_NONE;
+
+  if (entry_offset & 1) {
+    // The offset needs to be at least two byte aligned.
+    status_ = ARM_STATUS_INVALID_ALIGNMENT;
+    return false;
+  }
+
+  // Each entry is a 32 bit prel31 offset followed by 32 bits
+  // of unwind information. If bit 31 of the unwind data is zero,
+  // then this is a prel31 offset to the start of the unwind data.
+  // If the unwind data is 1, then this is a cant unwind entry.
+  // Otherwise, this data is the compact form of the unwind information.
+  uint32_t data;
+  if (!elf_memory_->Read32(entry_offset + 4, &data)) {
+    status_ = ARM_STATUS_READ_FAILED;
+    return false;
+  }
+  if (data == 1) {
+    // This is a CANT UNWIND entry.
+    status_ = ARM_STATUS_NO_UNWIND;
+    if (log_) {
+      log(log_indent_, "Raw Data: 0x00 0x00 0x00 0x01");
+      log(log_indent_, "[cantunwind]");
+    }
+    return false;
+  }
+
+  if (data & (1UL << 31)) {
+    // This is a compact table entry.
+    if ((data >> 24) & 0xf) {
+      // This is a non-zero index, this code doesn't support
+      // other formats.
+      status_ = ARM_STATUS_INVALID_PERSONALITY;
+      return false;
+    }
+    data_.push_back((data >> 16) & 0xff);
+    data_.push_back((data >> 8) & 0xff);
+    uint8_t last_op = data & 0xff;
+    data_.push_back(last_op);
+    if (last_op != ARM_OP_FINISH) {
+      // If this didn't end with a finish op, add one.
+      data_.push_back(ARM_OP_FINISH);
+    }
+    if (log_) {
+      LogRawData();
+    }
+    return true;
+  }
+
+  // Get the address of the ops.
+  // Sign extend the data value if necessary.
+  int32_t signed_data = static_cast<int32_t>(data << 1) >> 1;
+  uint32_t addr = (entry_offset + 4) + signed_data;
+  if (!elf_memory_->Read32(addr, &data)) {
+    status_ = ARM_STATUS_READ_FAILED;
+    return false;
+  }
+
+  size_t num_table_words;
+  if (data & (1UL << 31)) {
+    // Compact model.
+    switch ((data >> 24) & 0xf) {
+    case 0:
+      num_table_words = 0;
+      data_.push_back((data >> 16) & 0xff);
+      break;
+    case 1:
+    case 2:
+      num_table_words = (data >> 16) & 0xff;
+      addr += 4;
+      break;
+    default:
+      // Only a personality of 0, 1, 2 is valid.
+      status_ = ARM_STATUS_INVALID_PERSONALITY;
+      return false;
+    }
+    data_.push_back((data >> 8) & 0xff);
+    data_.push_back(data & 0xff);
+  } else {
+    // Generic model.
+
+    // Skip the personality routine data, it doesn't contain any data
+    // needed to decode the unwind information.
+    addr += 4;
+    if (!elf_memory_->Read32(addr, &data)) {
+      status_ = ARM_STATUS_READ_FAILED;
+      return false;
+    }
+    num_table_words = (data >> 24) & 0xff;
+    data_.push_back((data >> 16) & 0xff);
+    data_.push_back((data >> 8) & 0xff);
+    data_.push_back(data & 0xff);
+    addr += 4;
+  }
+
+  if (num_table_words > 5) {
+    status_ = ARM_STATUS_MALFORMED;
+    return false;
+  }
+
+  for (size_t i = 0; i < num_table_words; i++) {
+    if (!elf_memory_->Read32(addr, &data)) {
+      status_ = ARM_STATUS_READ_FAILED;
+      return false;
+    }
+    data_.push_back((data >> 24) & 0xff);
+    data_.push_back((data >> 16) & 0xff);
+    data_.push_back((data >> 8) & 0xff);
+    data_.push_back(data & 0xff);
+    addr += 4;
+  }
+
+  if (data_.back() != ARM_OP_FINISH) {
+    // If this didn't end with a finish op, add one.
+    data_.push_back(ARM_OP_FINISH);
+  }
+
+  if (log_) {
+    LogRawData();
+  }
+  return true;
+}
+
+inline bool ArmExidx::GetByte(uint8_t* byte) {
+  if (data_.empty()) {
+    status_ = ARM_STATUS_TRUNCATED;
+    return false;
+  }
+  *byte = data_.front();
+  data_.pop_front();
+  return true;
+}
+
+inline bool ArmExidx::DecodePrefix_10_00(uint8_t byte) {
+  assert((byte >> 4) == 0x8);
+
+  uint16_t registers = (byte & 0xf) << 8;
+  if (!GetByte(&byte)) {
+    return false;
+  }
+
+  registers |= byte;
+  if (registers == 0) {
+    // 10000000 00000000: Refuse to unwind
+    if (log_) {
+      log(log_indent_, "Refuse to unwind");
+    }
+    status_ = ARM_STATUS_NO_UNWIND;
+    return false;
+  }
+  // 1000iiii iiiiiiii: Pop up to 12 integer registers under masks {r15-r12}, {r11-r4}
+  if (log_) {
+    bool add_comma = false;
+    std::string msg = "pop {";
+    for (size_t i = 0; i < 12; i++) {
+      if (registers & (1 << i)) {
+        if (add_comma) {
+          msg += ", ";
+        }
+        msg += android::base::StringPrintf("r%zu", i + 4);
+        add_comma = true;
+      }
+    }
+    log(log_indent_, "%s}", msg.c_str());
+    if (log_skip_execution_) {
+      return true;
+    }
+  }
+
+  registers <<= 4;
+  for (size_t reg = 4; reg < 16; reg++) {
+    if (registers & (1 << reg)) {
+      if (!process_memory_->Read32(cfa_, &(*regs_)[reg])) {
+        status_ = ARM_STATUS_READ_FAILED;
+        return false;
+      }
+      cfa_ += 4;
+    }
+  }
+  // If the sp register is modified, change the cfa value.
+  if (registers & (1 << ARM_REG_SP)) {
+    cfa_ = (*regs_)[ARM_REG_SP];
+  }
+  return true;
+}
+
+inline bool ArmExidx::DecodePrefix_10_01(uint8_t byte) {
+  assert((byte >> 4) == 0x9);
+
+  uint8_t bits = byte & 0xf;
+  if (bits == 13 || bits == 15) {
+    // 10011101: Reserved as prefix for ARM register to register moves
+    // 10011111: Reserved as prefix for Intel Wireless MMX register to register moves
+    if (log_) {
+      log(log_indent_, "[Reserved]");
+    }
+    status_ = ARM_STATUS_RESERVED;
+    return false;
+  }
+  // 1001nnnn: Set vsp = r[nnnn] (nnnn != 13, 15)
+  if (log_) {
+    log(log_indent_, "vsp = r%d", bits);
+    if (log_skip_execution_) {
+      return true;
+    }
+  }
+  // It is impossible for bits to be larger than the total number of
+  // arm registers, so don't bother checking if bits is a valid register.
+  cfa_ = (*regs_)[bits];
+  return true;
+}
+
+inline bool ArmExidx::DecodePrefix_10_10(uint8_t byte) {
+  assert((byte >> 4) == 0xa);
+
+  // 10100nnn: Pop r4-r[4+nnn]
+  // 10101nnn: Pop r4-r[4+nnn], r14
+  if (log_) {
+    std::string msg = "pop {r4";
+    uint8_t end_reg = byte & 0x7;
+    if (end_reg) {
+      msg += android::base::StringPrintf("-r%d", 4 + end_reg);
+    }
+    if (byte & 0x8) {
+      log(log_indent_, "%s, r14}", msg.c_str());
+    } else {
+      log(log_indent_, "%s}", msg.c_str());
+    }
+    if (log_skip_execution_) {
+      return true;
+    }
+  }
+
+  for (size_t i = 4; i <= 4 + (byte & 0x7); i++) {
+    if (!process_memory_->Read32(cfa_, &(*regs_)[i])) {
+      status_ = ARM_STATUS_READ_FAILED;
+      return false;
+    }
+    cfa_ += 4;
+  }
+  if (byte & 0x8) {
+    if (!process_memory_->Read32(cfa_, &(*regs_)[ARM_REG_R14])) {
+      status_ = ARM_STATUS_READ_FAILED;
+      return false;
+    }
+    cfa_ += 4;
+  }
+  return true;
+}
+
+inline bool ArmExidx::DecodePrefix_10_11_0000() {
+  // 10110000: Finish
+  if (log_) {
+    log(log_indent_, "finish");
+    if (log_skip_execution_) {
+      status_ = ARM_STATUS_FINISH;
+      return false;
+    }
+  }
+  if (!(*regs_)[ARM_REG_PC]) {
+    (*regs_)[ARM_REG_PC] = (*regs_)[ARM_REG_LR];
+  }
+  status_ = ARM_STATUS_FINISH;
+  return false;
+}
+
+inline bool ArmExidx::DecodePrefix_10_11_0001() {
+  uint8_t byte;
+  if (!GetByte(&byte)) {
+    return false;
+  }
+
+  if (byte == 0) {
+    // 10110001 00000000: Spare
+    if (log_) {
+      log(log_indent_, "Spare");
+    }
+    status_ = ARM_STATUS_SPARE;
+    return false;
+  }
+  if (byte >> 4) {
+    // 10110001 xxxxyyyy: Spare (xxxx != 0000)
+    if (log_) {
+      log(log_indent_, "Spare");
+    }
+    status_ = ARM_STATUS_SPARE;
+    return false;
+  }
+
+  // 10110001 0000iiii: Pop integer registers under mask {r3, r2, r1, r0}
+  if (log_) {
+    bool add_comma = false;
+    std::string msg = "pop {";
+    for (size_t i = 0; i < 4; i++) {
+      if (byte & (1 << i)) {
+        if (add_comma) {
+          msg += ", ";
+        }
+        msg += android::base::StringPrintf("r%zu", i);
+        add_comma = true;
+      }
+    }
+    log(log_indent_, "%s}", msg.c_str());
+    if (log_skip_execution_) {
+      return true;
+    }
+  }
+
+  for (size_t reg = 0; reg < 4; reg++) {
+    if (byte & (1 << reg)) {
+      if (!process_memory_->Read32(cfa_, &(*regs_)[reg])) {
+        status_ = ARM_STATUS_READ_FAILED;
+        return false;
+      }
+      cfa_ += 4;
+    }
+  }
+  return true;
+}
+
+inline bool ArmExidx::DecodePrefix_10_11_0010() {
+  // 10110010 uleb128: vsp = vsp + 0x204 + (uleb128 << 2)
+  uint32_t result = 0;
+  uint32_t shift = 0;
+  uint8_t byte;
+  do {
+    if (!GetByte(&byte)) {
+      return false;
+    }
+
+    result |= (byte & 0x7f) << shift;
+    shift += 7;
+  } while (byte & 0x80);
+  result <<= 2;
+  if (log_) {
+    log(log_indent_, "vsp = vsp + %d", 0x204 + result);
+    if (log_skip_execution_) {
+      return true;
+    }
+  }
+  cfa_ += 0x204 + result;
+  return true;
+}
+
+inline bool ArmExidx::DecodePrefix_10_11_0011() {
+  // 10110011 sssscccc: Pop VFP double precision registers D[ssss]-D[ssss+cccc] by FSTMFDX
+  uint8_t byte;
+  if (!GetByte(&byte)) {
+    return false;
+  }
+
+  if (log_) {
+    uint8_t start_reg = byte >> 4;
+    std::string msg = android::base::StringPrintf("pop {d%d", start_reg);
+    uint8_t end_reg = start_reg + (byte & 0xf);
+    if (end_reg) {
+      msg += android::base::StringPrintf("-d%d", end_reg);
+    }
+    log(log_indent_, "%s}", msg.c_str());
+    if (log_skip_execution_) {
+      return true;
+    }
+  }
+  cfa_ += (byte & 0xf) * 8 + 12;
+  return true;
+}
+
+inline bool ArmExidx::DecodePrefix_10_11_01nn() {
+  // 101101nn: Spare
+  if (log_) {
+    log(log_indent_, "Spare");
+  }
+  status_ = ARM_STATUS_SPARE;
+  return false;
+}
+
+inline bool ArmExidx::DecodePrefix_10_11_1nnn(uint8_t byte) {
+  assert((byte & ~0x07) == 0xb8);
+
+  // 10111nnn: Pop VFP double-precision registers D[8]-D[8+nnn] by FSTMFDX
+  if (log_) {
+    std::string msg = "pop {d8";
+    uint8_t last_reg = (byte & 0x7);
+    if (last_reg) {
+      msg += android::base::StringPrintf("-d%d", last_reg + 8);
+    }
+    log(log_indent_, "%s}", msg.c_str());
+    if (log_skip_execution_) {
+      return true;
+    }
+  }
+  // Only update the cfa.
+  cfa_ += (byte & 0x7) * 8 + 12;
+  return true;
+}
+
+inline bool ArmExidx::DecodePrefix_10(uint8_t byte) {
+  assert((byte >> 6) == 0x2);
+
+  switch ((byte >> 4) & 0x3) {
+  case 0:
+    return DecodePrefix_10_00(byte);
+  case 1:
+    return DecodePrefix_10_01(byte);
+  case 2:
+    return DecodePrefix_10_10(byte);
+  default:
+    switch (byte & 0xf) {
+    case 0:
+      return DecodePrefix_10_11_0000();
+    case 1:
+      return DecodePrefix_10_11_0001();
+    case 2:
+      return DecodePrefix_10_11_0010();
+    case 3:
+      return DecodePrefix_10_11_0011();
+    default:
+      if (byte & 0x8) {
+        return DecodePrefix_10_11_1nnn(byte);
+      } else {
+        return DecodePrefix_10_11_01nn();
+      }
+    }
+  }
+}
+
+inline bool ArmExidx::DecodePrefix_11_000(uint8_t byte) {
+  assert((byte & ~0x07) == 0xc0);
+
+  uint8_t bits = byte & 0x7;
+  if (bits == 6) {
+    if (!GetByte(&byte)) {
+      return false;
+    }
+
+    // 11000110 sssscccc: Intel Wireless MMX pop wR[ssss]-wR[ssss+cccc]
+    if (log_) {
+      uint8_t start_reg = byte >> 4;
+      std::string msg = android::base::StringPrintf("pop {wR%d", start_reg);
+      uint8_t end_reg = byte & 0xf;
+      if (end_reg) {
+        msg += android::base::StringPrintf("-wR%d", start_reg + end_reg);
+      }
+      log(log_indent_, "%s}", msg.c_str());
+      if (log_skip_execution_) {
+        return true;
+      }
+    }
+    // Only update the cfa.
+    cfa_ += (byte & 0xf) * 8 + 8;
+  } else if (bits == 7) {
+    if (!GetByte(&byte)) {
+      return false;
+    }
+
+    if (byte == 0) {
+      // 11000111 00000000: Spare
+      if (log_) {
+        log(log_indent_, "Spare");
+      }
+      status_ = ARM_STATUS_SPARE;
+      return false;
+    } else if ((byte >> 4) == 0) {
+      // 11000111 0000iiii: Intel Wireless MMX pop wCGR registers {wCGR0,1,2,3}
+      if (log_) {
+        bool add_comma = false;
+        std::string msg = "pop {";
+        for (size_t i = 0; i < 4; i++) {
+          if (byte & (1 << i)) {
+            if (add_comma) {
+              msg += ", ";
+            }
+            msg += android::base::StringPrintf("wCGR%zu", i);
+            add_comma = true;
+          }
+        }
+        log(log_indent_, "%s}", msg.c_str());
+      }
+      // Only update the cfa.
+      cfa_ += __builtin_popcount(byte) * 4;
+    } else {
+      // 11000111 xxxxyyyy: Spare (xxxx != 0000)
+      if (log_) {
+        log(log_indent_, "Spare");
+      }
+      status_ = ARM_STATUS_SPARE;
+      return false;
+    }
+  } else {
+    // 11000nnn: Intel Wireless MMX pop wR[10]-wR[10+nnn] (nnn != 6, 7)
+    if (log_) {
+      std::string msg = "pop {wR10";
+      uint8_t nnn = byte & 0x7;
+      if (nnn) {
+        msg += android::base::StringPrintf("-wR%d", 10 + nnn);
+      }
+      log(log_indent_, "%s}", msg.c_str());
+      if (log_skip_execution_) {
+        return true;
+      }
+    }
+    // Only update the cfa.
+    cfa_ += (byte & 0x7) * 8 + 8;
+  }
+  return true;
+}
+
+inline bool ArmExidx::DecodePrefix_11_001(uint8_t byte) {
+  assert((byte & ~0x07) == 0xc8);
+
+  uint8_t bits = byte & 0x7;
+  if (bits == 0) {
+    // 11001000 sssscccc: Pop VFP double precision registers D[16+ssss]-D[16+ssss+cccc] by VPUSH
+    if (!GetByte(&byte)) {
+      return false;
+    }
+
+    if (log_) {
+      uint8_t start_reg = byte >> 4;
+      std::string msg = android::base::StringPrintf("pop {d%d", 16 + start_reg);
+      uint8_t end_reg = byte & 0xf;
+      if (end_reg) {
+        msg += android::base::StringPrintf("-d%d", 16 + start_reg + end_reg);
+      }
+      log(log_indent_, "%s}", msg.c_str());
+      if (log_skip_execution_) {
+        return true;
+      }
+    }
+    // Only update the cfa.
+    cfa_ += (byte & 0xf) * 8 + 8;
+  } else if (bits == 1) {
+    // 11001001 sssscccc: Pop VFP double precision registers D[ssss]-D[ssss+cccc] by VPUSH
+    if (!GetByte(&byte)) {
+      return false;
+    }
+
+    if (log_) {
+      uint8_t start_reg = byte >> 4;
+      std::string msg = android::base::StringPrintf("pop {d%d", start_reg);
+      uint8_t end_reg = byte & 0xf;
+      if (end_reg) {
+        msg += android::base::StringPrintf("-d%d", start_reg + end_reg);
+      }
+      log(log_indent_, "%s}", msg.c_str());
+      if (log_skip_execution_) {
+        return true;
+      }
+    }
+    // Only update the cfa.
+    cfa_ += (byte & 0xf) * 8 + 8;
+  } else {
+    // 11001yyy: Spare (yyy != 000, 001)
+    if (log_) {
+      log(log_indent_, "Spare");
+    }
+    status_ = ARM_STATUS_SPARE;
+    return false;
+  }
+  return true;
+}
+
+inline bool ArmExidx::DecodePrefix_11_010(uint8_t byte) {
+  assert((byte & ~0x07) == 0xd0);
+
+  // 11010nnn: Pop VFP double precision registers D[8]-D[8+nnn] by VPUSH
+  if (log_) {
+    std::string msg = "pop {d8";
+    uint8_t end_reg = byte & 0x7;
+    if (end_reg) {
+      msg += android::base::StringPrintf("-d%d", 8 + end_reg);
+    }
+    log(log_indent_, "%s}", msg.c_str());
+    if (log_skip_execution_) {
+      return true;
+    }
+  }
+  cfa_ += (byte & 0x7) * 8 + 8;
+  return true;
+}
+
+inline bool ArmExidx::DecodePrefix_11(uint8_t byte) {
+  assert((byte >> 6) == 0x3);
+
+  switch ((byte >> 3) & 0x7) {
+  case 0:
+    return DecodePrefix_11_000(byte);
+  case 1:
+    return DecodePrefix_11_001(byte);
+  case 2:
+    return DecodePrefix_11_010(byte);
+  default:
+    // 11xxxyyy: Spare (xxx != 000, 001, 010)
+    if (log_) {
+      log(log_indent_, "Spare");
+    }
+    status_ = ARM_STATUS_SPARE;
+    return false;
+  }
+}
+
+bool ArmExidx::Decode() {
+  status_ = ARM_STATUS_NONE;
+  uint8_t byte;
+  if (!GetByte(&byte)) {
+    return false;
+  }
+
+  switch (byte >> 6) {
+  case 0:
+    // 00xxxxxx: vsp = vsp + (xxxxxxx << 2) + 4
+    if (log_) {
+      log(log_indent_, "vsp = vsp + %d", ((byte & 0x3f) << 2) + 4);
+      if (log_skip_execution_) {
+        break;
+      }
+    }
+    cfa_ += ((byte & 0x3f) << 2) + 4;
+    break;
+  case 1:
+    // 01xxxxxx: vsp = vsp - (xxxxxxx << 2) + 4
+    if (log_) {
+      log(log_indent_, "vsp = vsp - %d", ((byte & 0x3f) << 2) + 4);
+      if (log_skip_execution_) {
+        break;
+      }
+    }
+    cfa_ -= ((byte & 0x3f) << 2) + 4;
+    break;
+  case 2:
+    return DecodePrefix_10(byte);
+  default:
+    return DecodePrefix_11(byte);
+  }
+  return true;
+}
+
+bool ArmExidx::Eval() {
+  while (Decode());
+  return status_ == ARM_STATUS_FINISH;
+}