Re: [NEWS/RFA] Re: [gdbserver] x86 agent expression bytecode compiler (speed up conditional tracepoints)

[Doug Evans <dje at google dot com>]

On Mon, Jun 14, 2010 at 3:19 PM, Pedro Alves <pedro@codesourcery.com> wrote:
>>
> Thanks. ?I've checked the whole thing in.

I'm getting build failures that go away when compiling linux-x86-low.c with -g.

gcc is optimizing out the skipped over stuff I believe.


/* Our general strategy for emitting code is to avoid specifying raw
   bytes whenever possible, and instead copy a block of inline asm
   that is embedded in the function.  This is a little messy, because
   we need to keep the compiler from discarding what looks like dead
   code, plus suppress various warnings.  */

#define EMIT_ASM(NAME,INSNS)                                            \
  { extern unsigned char start_ ## NAME, end_ ## NAME;                  \
    add_insns (&start_ ## NAME, &end_ ## NAME - &start_ ## NAME);       \
    if (always_true ())                                         \
      goto skipover ## NAME;                                            \
    __asm__ ("start_" #NAME ":\n\t" INSNS "\n\tend_" #NAME ":\n\t");    \
    skipover ## NAME:                                                   \
    ; }