gdb: disassembler opcode display formatting

[binutils-gdb.git] / gdb / disasm.c

diff --git a/gdb/disasm.c b/gdb/disasm.c
index ba6ac2d4827e190d03f6d120b3d2ffd353838399..b5e503fd71d07794edbcd5079d4aa6be792d0b63 100644 (file)
--- a/gdb/disasm.c
+++ b/gdb/disasm.c
@@ -457,7 +457,7 @@ gdb_pretty_print_disassembler::pretty_print_insn (const struct disasm_insn *insn
        throw ex;
       }
 
-    if (flags & DISASSEMBLY_RAW_INSN)
+    if ((flags & (DISASSEMBLY_RAW_INSN | DISASSEMBLY_RAW_BYTES)) != 0)
       {
        /* Build the opcodes using a temporary stream so we can
           write them out in a single go for the MI.  */
@@ -467,14 +467,51 @@ gdb_pretty_print_disassembler::pretty_print_insn (const struct disasm_insn *insn
        m_opcode_data.resize (size);
        read_code (pc, m_opcode_data.data (), size);
 
-       for (int i = 0; i < size; ++i)
+       /* The disassembler provides information about the best way to
+          display the instruction bytes to the user.  We provide some sane
+          defaults in case the disassembler gets it wrong.  */
+       const struct disassemble_info *di = m_di.disasm_info ();
+       int bytes_per_line = std::max (di->bytes_per_line, size);
+       int bytes_per_chunk = std::max (di->bytes_per_chunk, 1);
+
+       /* If the user has requested the instruction bytes be displayed
+          byte at a time, then handle that here.  Also, if the instruction
+          is not a multiple of the chunk size (which probably indicates a
+          disassembler problem) then avoid that causing display problems
+          by switching to byte at a time mode.  */
+       if ((flags & DISASSEMBLY_RAW_BYTES) != 0
+           || (size % bytes_per_chunk) != 0)
+         bytes_per_chunk = 1;
+
+       /* Print the instruction opcodes bytes, grouped into chunks.  */
+       for (int i = 0; i < size; i += bytes_per_chunk)
          {
            if (i > 0)
              m_opcode_stb.puts (" ");
-           m_opcode_stb.printf ("%02x", (unsigned) m_opcode_data[i]);
+
+           if (di->display_endian == BFD_ENDIAN_LITTLE)
+             {
+               for (int k = bytes_per_chunk; k-- != 0; )
+                 m_opcode_stb.printf ("%02x", (unsigned) m_opcode_data[i + k]);
+             }
+           else
+             {
+               for (int k = 0; k < bytes_per_chunk; k++)
+                 m_opcode_stb.printf ("%02x", (unsigned) m_opcode_data[i + k]);
+             }
+         }
+
+       /* Calculate required padding.  */
+       int nspaces = 0;
+       for (int i = size; i < bytes_per_line; i += bytes_per_chunk)
+         {
+           if (i > size)
+             nspaces++;
+           nspaces += bytes_per_chunk * 2;
          }
 
        m_uiout->field_stream ("opcodes", m_opcode_stb);
+       m_uiout->spaces (nspaces);
        m_uiout->text ("\t");
       }