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 <irogers@google.com>
Tested-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Colin Ian King <colin.i.king@gmail.com>
Cc: Dapeng Mi <dapeng1.mi@linux.intel.com>
Cc: Howard Chu <howardchu95@gmail.com>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Veronika Molnarova <vmolnaro@redhat.com>
Cc: Weilin Wang <weilin.wang@intel.com>
Link: https://lore.kernel.org/r/20241119011644.971342-13-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

5 files changed, 19 insertions, 10 deletions

diff --git a/tools/perf/arch/x86/util/Build b/tools/perf/arch/x86/util/Build
index 848327378694..06d7c0205b3d 100644
--- a/tools/perf/arch/x86/util/Build
+++ b/tools/perf/arch/x86/util/Build
@@ -15,6 +15,6 @@ perf-util-$(CONFIG_LOCAL_LIBUNWIND)    += unwind-libunwind.o
 perf-util-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o
 
 perf-util-$(CONFIG_AUXTRACE) += auxtrace.o
-perf-util-$(CONFIG_AUXTRACE) += archinsn.o
+perf-util-y += archinsn.o
 perf-util-$(CONFIG_AUXTRACE) += intel-pt.o
 perf-util-$(CONFIG_AUXTRACE) += intel-bts.o
diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index e1c8d191c510..f8e77c53e2f9 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -123,7 +123,7 @@ perf-util-y += iostat.o
 perf-util-y += stream.o
 perf-util-y += kvm-stat.o
 perf-util-$(CONFIG_AUXTRACE) += auxtrace.o
-perf-util-$(CONFIG_AUXTRACE) += intel-pt-decoder/
+perf-util-y += intel-pt-decoder/
 perf-util-$(CONFIG_AUXTRACE) += intel-pt.o
 perf-util-$(CONFIG_AUXTRACE) += intel-bts.o
 perf-util-$(CONFIG_AUXTRACE) += arm-spe.o
diff --git a/tools/perf/util/intel-pt-decoder/Build b/tools/perf/util/intel-pt-decoder/Build
index 30793d08c6d4..f99d150059b9 100644
--- a/tools/perf/util/intel-pt-decoder/Build
+++ b/tools/perf/util/intel-pt-decoder/Build
@@ -9,14 +9,24 @@ $(OUTPUT)util/intel-pt-decoder/inat-tables.c: $(inat_tables_script) $(inat_table
 
 # Busybox's diff doesn't have -I, avoid warning in the case
 
-$(OUTPUT)util/intel-pt-decoder/intel-pt-insn-decoder.o: util/intel-pt-decoder/intel-pt-insn-decoder.c $(OUTPUT)util/intel-pt-decoder/inat-tables.c
+ifeq ($(SRCARCH),x86)
+  perf-util-y += inat.o insn.o
+else
+  perf-util-$(CONFIG_AUXTRACE) += inat.o insn.o
+endif
+
+$(OUTPUT)util/intel-pt-decoder/inat.o: $(srctree)/tools/arch/x86/lib/inat.c $(OUTPUT)util/intel-pt-decoder/inat-tables.c
 	$(call rule_mkdir)
 	$(call if_changed_dep,cc_o_c)
 
-CFLAGS_intel-pt-insn-decoder.o += -I$(OUTPUT)util/intel-pt-decoder
+CFLAGS_inat.o += -I$(OUTPUT)util/intel-pt-decoder
+
+$(OUTPUT)util/intel-pt-decoder/insn.o: $(srctree)/tools/arch/x86/lib/insn.c
+	$(call rule_mkdir)
+	$(call if_changed_dep,cc_o_c)
 
 ifeq ($(CC_NO_CLANG), 1)
-  CFLAGS_intel-pt-insn-decoder.o += -Wno-override-init
+  CFLAGS_insn.o += -Wno-override-init
 endif
 
-CFLAGS_intel-pt-insn-decoder.o += -Wno-packed
+CFLAGS_insn.o += -Wno-packed
diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-insn-decoder.c b/tools/perf/util/intel-pt-decoder/intel-pt-insn-decoder.c
index 47cf35799a4d..8fabddc1c0da 100644
--- a/tools/perf/util/intel-pt-decoder/intel-pt-insn-decoder.c
+++ b/tools/perf/util/intel-pt-decoder/intel-pt-insn-decoder.c
@@ -11,9 +11,6 @@
 #include <byteswap.h>
 #include "../../../arch/x86/include/asm/insn.h"
 
-#include "../../../arch/x86/lib/inat.c"
-#include "../../../arch/x86/lib/insn.c"
-
 #include "event.h"
 
 #include "intel-pt-insn-decoder.h"
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)