opcodes/riscv: prevent future use of disassemble_info::fprintf_func

The previous commit removed a use of disassemble_info::fprintf_func
which had been added to the RISC-V disassembler after the disassembler
had been switched to use ::fprintf_styled_func, for styled output.

To prevent future mistakes, I propose adding a #define to rename
fprintf_func to something which does not exist.  If this had been in
place then the before the previous commit libopcodes would have failed
to compile, like this:

  ../../src/opcodes/riscv-dis.c: In function ‘print_reg_list’:
  ../../src/opcodes/riscv-dis.c:229:7: error: ‘disassemble_info’ {aka ‘struct disassemble_info’} has no member named ‘please_use_fprintf_styled_func_instead’
    229 |   info->fprintf_func (info->stream, "%s", riscv_gpr_names[X_RA]);
        |       ^~

If this commit is accepted then I'll follow up with another commit
that adds the same #define to every disassembler that has been
converted to use styled output.

As the RISC-V disassembler is now fully styled, this commit should
make no difference at all.

1 files changed, 5 insertions, 0 deletions

diff --git a/opcodes/riscv-dis.c b/opcodes/riscv-dis.c
index b04a6e7..9c5e6ce 100644
--- a/opcodes/riscv-dis.c
+++ b/opcodes/riscv-dis.c
@@ -32,6 +32,11 @@
 #include <stdint.h>
 #include <ctype.h>
 
+/* The RISC-V disassembler produces styled output using
+   disassemble_info::fprintf_styled_func.  This define prevents use of
+   disassemble_info::fprintf_func which is for unstyled output.  */
+#define fprintf_func please_use_fprintf_styled_func_instead
+
 /* Current XLEN for the disassembler.  */
 static unsigned xlen = 0;