Re: [PATCH 2/3] perf disasm: Define stubs for the LLVM and capstone disassemblers

[Aditya Bodkhe <Aditya.Bodkhe1@ibm.com>]

> On 11 Nov 2024, at 8:47 PM, Arnaldo Carvalho de Melo <acme@kernel.org> wrote:
> 
> From: Arnaldo Carvalho de Melo <acme@redhat.com>
> 
> This reduces the number of ifdefs in the main symbol__disassemble()
> method and paves the way for allowing the user to configure the
> disassemblers of preference.
> 
> Cc: Adrian Hunter <adrian.hunter@intel.com>
> Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
> Cc: Ian Rogers <irogers@google.com>
> Cc: Jiri Olsa <jolsa@kernel.org>
> Cc: Kan Liang <kan.liang@linux.intel.com>
> Cc: Namhyung Kim <namhyung@kernel.org>
> Cc: Steinar H. Gunderson <sesse@google.com>
> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
> ---
> tools/perf/util/disasm.c | 40 ++++++++++++++++++++++++++++++++--------
> 1 file changed, 32 insertions(+), 8 deletions(-)
> 
> diff --git a/tools/perf/util/disasm.c b/tools/perf/util/disasm.c
> index 36cf61602c17fe69..83df1da20a7b16cd 100644
> --- a/tools/perf/util/disasm.c
> +++ b/tools/perf/util/disasm.c
> @@ -1422,6 +1422,13 @@ read_symbol(const char *filename, struct map *map, struct symbol *sym,
> 	free(buf);
> 	return NULL;
> }
> +#else // defined(HAVE_LIBCAPSTONE_SUPPORT) || defined(HAVE_LIBLLVM_SUPPORT)
> +static void symbol__disassembler_missing(const char *disassembler, const char *filename,
> +					 struct symbol *sym)
> +{
> +	pr_debug("The %s disassembler isn't linked in for %s in %s\n",
> +		 disassembler, sym->name, filename);
> +}
> #endif
> 
> #ifdef HAVE_LIBCAPSTONE_SUPPORT
> @@ -1715,7 +1722,20 @@ static int symbol__disassemble_capstone(char *filename, struct symbol *sym,
> 	count = -1;
> 	goto out;
> }
> -#endif
> +#else // HAVE_LIBCAPSTONE_SUPPORT
> +static int symbol__disassemble_capstone(char *filename, struct symbol *sym,
> +					struct annotate_args *args)
> +	symbol__disassembler_missing("capstone", filename, sym);
> +	return -1;
> +}
Hi Arnaldo
I was testing this change in powerpc setup I see below compilation error

CC   util/disasm.o
util/disasm.c: In function ‘symbol__disassemble_capstone’:
util/disasm.c:1728:9: error: expected declaration specifiers before ‘symbol__disassembler_missing’
 1728 |     symbol__disassembler_missing("capstone", filename, sym);
   |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
util/disasm.c:1729:9: error: expected declaration specifiers before ‘return’
 1729 |     return -1;
   |     ^~~~~~
util/disasm.c:1730:1: error: expected declaration specifiers before ‘}’ token
 1730 | }

Below patch fixes the issue

diff --git a/tools/perf/util/disasm.c b/tools/perf/util/disasm.c
index df6c172c9c7f..da22b6ab9ecf 100644
--- a/tools/perf/util/disasm.c
+++ b/tools/perf/util/disasm.c
@@ -1724,7 +1724,8 @@ static int symbol__disassemble_capstone(char *filename, struct symbol *sym,
 }
 #else // HAVE_LIBCAPSTONE_SUPPORT
 static int symbol__disassemble_capstone(char *filename, struct symbol *sym,
-                    struct annotate_args *args)
+                    struct annotate_args *args __maybe_unused)
+{
    symbol__disassembler_missing("capstone", filename, sym);
    return -1;
 }

I tried with tmp.perf-tools-next , I have tested the above patch fixes the compilation error

Thanks 
Aditya Bodkhe
> +
> +static int symbol__disassemble_capstone_powerpc(char *filename, struct symbol *sym,
> +						struct annotate_args *args __maybe_unused)
> +{
> +	symbol__disassembler_missing("capstone powerpc", filename, sym);
> +	return -1;
> +}
> +#endif // HAVE_LIBCAPSTONE_SUPPORT
> 
> static int symbol__disassemble_raw(char *filename, struct symbol *sym,
> 					struct annotate_args *args)
> @@ -1983,7 +2003,14 @@ static int symbol__disassemble_llvm(char *filename, struct symbol *sym,
> 	free(line_storage);
> 	return ret;
> }
> -#endif
> +#else // HAVE_LIBLLVM_SUPPORT
> +static int symbol__disassemble_llvm(char *filename, struct symbol *sym,
> +				    struct annotate_args *args __maybe_unused)
> +{
> +	symbol__disassembler_missing("LLVM", filename, sym);
> +	return -1;
> +}
> +#endif // HAVE_LIBLLVM_SUPPORT
> 
> /*
>  * Possibly create a new version of line with tabs expanded. Returns the
> @@ -2242,24 +2269,21 @@ int symbol__disassemble(struct symbol *sym, struct annotate_args *args)
> 			err = symbol__disassemble_raw(symfs_filename, sym, args);
> 			if (err == 0)
> 				goto out_remove_tmp;
> -#ifdef HAVE_LIBCAPSTONE_SUPPORT
> +
> 			err = symbol__disassemble_capstone_powerpc(symfs_filename, sym, args);
> 			if (err == 0)
> 				goto out_remove_tmp;
> -#endif
> 		}
> 	}
> 
> -#ifdef HAVE_LIBLLVM_SUPPORT
> 	err = symbol__disassemble_llvm(symfs_filename, sym, args);
> 	if (err == 0)
> 		goto out_remove_tmp;
> -#endif
> -#ifdef HAVE_LIBCAPSTONE_SUPPORT
> +
> 	err = symbol__disassemble_capstone(symfs_filename, sym, args);
> 	if (err == 0)
> 		goto out_remove_tmp;
> -#endif
> +
> 	err = symbol__disassemble_objdump(symfs_filename, sym, args);
> 
> out_remove_tmp:
> -- 
> 2.47.0
> 
>