perf x86: Define arch_fetch_insn in NO_AUXTRACE builds

archinsn.c containing arch_fetch_insn was only enabled with
CONFIG_AUXTRACE, but this meant that a NO_AUXTRACE build on x86 would
use the empty weak version of arch_fetch_insn - weak symbols are a
frequent source of errors like this and are outside of the C
specification. Change it so that archinsn.c is always built on x86 and
make the weak symbol empty version of arch_fetch_insn a strong one
guarded by ifdefs.

arch_fetch_insn on x86 depends on insn_decode which is a function
included then built into intel-pt-insn-decoder.c.
intel-pt-insn-decoder.c isn't built in a NO_AUXTRACE=1 build. Separate
the insn_decode function from intel-pt-insn-decoder.c by just directly
compiling the relevant file. Guard this compilation to be for either
always on x86 (because of the use in arch_fetch_insn) or when auxtrace
is enabled. Apply the CFLAGS overrides as necessary, reducing the amount
of code where warnings are disabled.

Signed-off-by: Ian Rogers <[email protected]>
Tested-by: Adrian Hunter <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Athira Rajeev <[email protected]>
Cc: Colin Ian King <[email protected]>
Cc: Dapeng Mi <[email protected]>
Cc: Howard Chu <[email protected]>
Cc: Ilya Leoshkevich <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: James Clark <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Michael Petlan <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Richter <[email protected]>
Cc: Veronika Molnarova <[email protected]>
Cc: Weilin Wang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

1 files changed, 3 insertions, 1 deletions

diff --git a/tools/perf/util/trace-event-scripting.c b/tools/perf/util/trace-event-scripting.c
index 04e3c9e29f95..4e81e02a4f18 100644
--- a/tools/perf/util/trace-event-scripting.c
+++ b/tools/perf/util/trace-event-scripting.c
@@ -274,11 +274,13 @@ void setup_perl_scripting(void)
 #endif
 #endif
 
-__weak void arch_fetch_insn(struct perf_sample *sample __maybe_unused,
+#if !defined(__i386__) && !defined(__x86_64__)
+void arch_fetch_insn(struct perf_sample *sample __maybe_unused,
 		     struct thread *thread __maybe_unused,
 		     struct machine *machine __maybe_unused)
 {
 }
+#endif
 
 void script_fetch_insn(struct perf_sample *sample, struct thread *thread,
 		       struct machine *machine, bool native_arch)