[aarch64] Handle unknown instruction encoding

We see the following build error:

 gdb/aarch64-tdep.c: In function 'aarch64_process_record':
 gdb/aarch64-tdep.c:2823:17: error: 'record_buf[0]' may be used uninitialized in this function [-Werror=maybe-uninitialized]
                 memcpy(&REGS[0], &RECORD_BUF[0], sizeof(uint32_t)*LENGTH); \
                 ^
 gdb/aarch64-tdep.c:3529:12: note: 'record_buf[0]' was declared here
   uint32_t record_buf[2];

since record_buf[0] isn't initialized in some paths in which
instruction encodings doesn't exist in current ARMv8 reference manual.
This patch is to let the function return AARCH64_RECORD_UNKNOWN for
these paths.

gdb:

2015-05-27  Yao Qi  <yao.qi@linaro.org>

	* aarch64-tdep.c (aarch64_record_data_proc_simd_fp): Return
	AARCH64_RECORD_UNKNOWN for unknown instruction encoding.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 3f3d2eb..9455492 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,10 @@
 2015-05-27  Yao Qi  <yao.qi@linaro.org>
 
+       * aarch64-tdep.c (aarch64_record_data_proc_simd_fp): Return
+       AARCH64_RECORD_UNKNOWN for unknown instruction encoding.
+
+2015-05-27  Yao Qi  <yao.qi@linaro.org>
+
        * aarch64-tdep.c (aarch64_record_branch_except_sys): Split lines
        before operator &&.
        (aarch64_record_load_store): Likewise.

diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c
index 8f1c7ef..9650a7a 100644 (file)
--- a/gdb/aarch64-tdep.c
+++ b/gdb/aarch64-tdep.c
@@ -3592,7 +3592,7 @@ aarch64_record_data_proc_simd_fp (insn_decode_record *aarch64_insn_r)
              record_buf[0] = AARCH64_CPSR_REGNUM;
            }
          /* Floating point - integer conversions instructions.  */
-         if (insn_bits12_15 == 0x00)
+         else if (insn_bits12_15 == 0x00)
            {
              /* Convert float to integer instruction.  */
              if (!(opcode >> 1) || ((opcode >> 1) == 0x02 && !rmode))
@@ -3621,8 +3621,14 @@ aarch64_record_data_proc_simd_fp (insn_decode_record *aarch64_insn_r)
                  else
                    record_buf[0] = reg_rd + AARCH64_V0_REGNUM;
                }
+             else
+               return AARCH64_RECORD_UNKNOWN;
             }
+         else
+           return AARCH64_RECORD_UNKNOWN;
         }
+      else
+       return AARCH64_RECORD_UNKNOWN;
     }
   else if ((insn_bits28_31 & 0x09) == 0x00 && insn_bits24_27 == 0x0e)
     {