Replace libdisasm with capstone

src/processor/disassembler_x86.h

 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 // copyright notice, this list of conditions and the following disclaimer
@@ skipping 10 matching lines @@
 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 // disassembler_x86.h: Basic x86 bytecode disassembler
 //
-// Provides a simple disassembler which wraps libdisasm. This allows simple
+// Provides a simple disassembler which wraps capstone. This allows simple
 // tests to be run against bytecode to test for various properties.
 //
 // Author: Cris Neckar
 
 #ifndef GOOGLE_BREAKPAD_PROCESSOR_DISASSEMBLER_X86_H_
 #define GOOGLE_BREAKPAD_PROCESSOR_DISASSEMBLER_X86_H_
 
 #include <stddef.h>
 #include <sys/types.h>
 
 #include "google_breakpad/common/breakpad_types.h"
 
-namespace libdis {
-#include "third_party/libdisasm/libdis.h"
-}
+#include "capstone.h"
+
 
 namespace google_breakpad {
 
+// Flags for current disassembler state.
 enum {
   DISX86_NONE =                 0x0,
   DISX86_BAD_BRANCH_TARGET =    0x1,
   DISX86_BAD_ARGUMENT_PASSED =  0x2,
   DISX86_BAD_WRITE =            0x4,
   DISX86_BAD_BLOCK_WRITE =      0x8,
   DISX86_BAD_READ =             0x10,
   DISX86_BAD_BLOCK_READ =       0x20,
   DISX86_BAD_COMPARISON =       0x40
 };
 
 class DisassemblerX86 {
   public:
     // TODO(cdn): Modify this class to take a MemoryRegion instead of just
     // a raw buffer. This will make it easier to use this on arbitrary
     // minidumps without first copying out the code segment.
     DisassemblerX86(const uint8_t *bytecode, uint32_t, uint32_t);
     ~DisassemblerX86();
 
     // This walks to the next instruction in the memory region and
     // sets flags based on the type of instruction and previous state
     // including any registers marked as bad through setBadRead()
     // or setBadWrite(). This method can be called in a loop to
     // disassemble until the end of a region.
-    uint32_t NextInstruction();
+    //
+    // Returns the size of the instruction in bytes, or zero if
+    // disassembly failed.
+    size_t NextInstruction();
 
     // Indicates whether the current disassembled instruction was valid.
     bool currentInstructionValid() { return instr_valid_; }
 
-    // Returns the current instruction as defined in libdis.h,
+    // Returns the current instruction as defined in capstone.h,
     // or NULL if the current instruction is not valid.
-    const libdis::x86_insn_t* currentInstruction() {
-      return instr_valid_ ? &current_instr_ : NULL;
+    const cs_insn* currentInstruction() {
+      return instr_valid_ ? current_instr_ : nullptr;
     }
 
-    // Returns the type of the current instruction as defined in libdis.h.
-    libdis::x86_insn_group currentInstructionGroup() {
-      return current_instr_.group;
+    // Returns true if the current instruction is in group.
+    bool currentInstructionIsGroup(x86_insn_group group) {
+      return instr_valid_ ?
+          cs_insn_group(handle_, current_instr_, group) : false;
     }
 
+    // Returns true if the current instruction is a block data instruction.
+    bool currentInstructionIsBlockData();
+
+
     // Indicates whether a return instruction has been encountered.
     bool endOfBlock() { return end_of_block_; }
 
-    // The flags set so far for the disassembly.
+    // The flags set so far for the disassembly, from the set defined in
+    // the anonymous enum above.
     uint16_t flags() { return flags_; }
 
     // This sets an indicator that the register used to determine
     // src or dest for the current instruction is tainted. These can
     // be used after examining the current instruction to indicate,
     // for example that a bad read or write occurred and the pointer
     // stored in the register is currently invalid.
     bool setBadRead();
     bool setBadWrite();
 
   protected:
-    const uint8_t *bytecode_;
-    uint32_t size_;
-    uint32_t virtual_address_;
-    uint32_t current_byte_offset_;
-    uint32_t current_inst_offset_;
+    // Memory containing instructions to disassemble.
+    // Owned by caller.
+    const uint8_t* bytecode_;
+    // Size of remaining bytecode.
+    size_t size_;
+    // Virtual address of current instruction.
+    uint64_t virtual_address_;
+
+    // capstone library handle
+    csh handle_;
 
     bool instr_valid_;
-    libdis::x86_insn_t current_instr_;
+    cs_insn* current_instr_;
 
     // TODO(cdn): Maybe also track an expression's index register.
     // ex: mov eax, [ebx + ecx]; ebx is base, ecx is index.
     bool register_valid_;
-    libdis::x86_reg_t bad_register_;
+    x86_reg bad_register_;
 
     bool pushed_bad_value_;
     bool end_of_block_;
 
     uint16_t flags_;
 };
 
 }  // namespace google_breakpad
 
 #endif  // GOOGLE_BREAKPAD_PROCESSOR_DISASSEMBLER_X86_H_