perf util: Add host_is_bigendian to util.h

Avoid libtraceevent dependency for tep_is_bigendian or trace-event.h
dependency for bigendian. Add a new host_is_bigendian to util.h, using
the compiler defined __BYTE_ORDER__ when available.

Committer notes:

Added:

 #else  /* !__BYTE_ORDER__ */

On that nested #ifdef block, as per Namhyung's suggestion.

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20221130062935.2219247-3-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/code-reading.c

@@ -16,7 +16,6 @@
 #include "dso.h"
 #include "env.h"
 #include "parse-events.h"
-#include "trace-event.h"
 #include "evlist.h"
 #include "evsel.h"
 #include "thread_map.h"
@@ -28,6 +27,7 @@
 #include "util/mmap.h"
 #include "util/string2.h"
 #include "util/synthetic-events.h"
+#include "util/util.h"
 #include "thread.h"
 
 #include "tests.h"
@@ -79,7 +79,7 @@ static size_t read_objdump_chunk(const char **line, unsigned char **buf,
 	 * see disassemble_bytes() at binutils/objdump.c for details
 	 * how objdump chooses display endian)
 	 */
-	if (bytes_read > 1 && !bigendian()) {
+	if (bytes_read > 1 && !host_is_bigendian()) {
 		unsigned char *chunk_end = chunk_start + bytes_read - 1;
 		unsigned char tmp;
 

tools/perf/tests/sample-parsing.c

@@ -13,7 +13,7 @@
 #include "evsel.h"
 #include "debug.h"
 #include "util/synthetic-events.h"
-#include "util/trace-event.h"
+#include "util/util.h"
 
 #include "tests.h"
 
@@ -117,7 +117,7 @@ static bool samples_same(const struct perf_sample *s1,
 		COMP(branch_stack->hw_idx);
 		for (i = 0; i < s1->branch_stack->nr; i++) {
 			if (needs_swap)
-				return ((tep_is_bigendian()) ?
+				return ((host_is_bigendian()) ?
 					(FLAG(s2).value == BS_EXPECTED_BE) :
 					(FLAG(s2).value == BS_EXPECTED_LE));
 			else

tools/perf/util/evsel.c

@@ -2320,11 +2320,8 @@ u64 evsel__bitfield_swap_branch_flags(u64 value)
 	 * as it has variable bit-field sizes. Instead the
 	 * macro takes the bit-field position/size,
 	 * swaps it based on the host endianness.
-	 *
-	 * tep_is_bigendian() is used here instead of
-	 * bigendian() to avoid python test fails.
 	 */
-	if (tep_is_bigendian()) {
+	if (host_is_bigendian()) {
 		new_val = bitfield_swap(value, 0, 1);
 		new_val |= bitfield_swap(value, 1, 1);
 		new_val |= bitfield_swap(value, 2, 1);

tools/perf/util/trace-event-info.c

@@ -26,6 +26,7 @@
 #include <api/fs/tracing_path.h>
 #include "evsel.h"
 #include "debug.h"
+#include "util.h"
 
 #define VERSION "0.6"
 #define MAX_EVENT_LENGTH 512
@@ -38,15 +39,6 @@ struct tracepoint_path {
 	struct tracepoint_path *next;
 };
 
-int bigendian(void)
-{
-	unsigned char str[] = { 0x1, 0x2, 0x3, 0x4, 0x0, 0x0, 0x0, 0x0};
-	unsigned int *ptr;
-
-	ptr = (unsigned int *)(void *)str;
-	return *ptr == 0x01020304;
-}
-
 /* unfortunately, you can not stat debugfs or proc files for size */
 static int record_file(const char *file, ssize_t hdr_sz)
 {
@@ -79,7 +71,7 @@ static int record_file(const char *file, ssize_t hdr_sz)
 
 	/* ugh, handle big-endian hdr_size == 4 */
 	sizep = (char*)&size;
-	if (bigendian())
+	if (host_is_bigendian())
 		sizep += sizeof(u64) - hdr_sz;
 
 	if (hdr_sz && pwrite(output_fd, sizep, hdr_sz, hdr_pos) < 0) {
@@ -564,7 +556,7 @@ static int tracing_data_header(void)
 		return -1;
 
 	/* save endian */
-	if (bigendian())
+	if (host_is_bigendian())
 		buf[0] = 1;
 	else
 		buf[0] = 0;

tools/perf/util/trace-event-read.c

@@ -17,6 +17,7 @@
 
 #include "trace-event.h"
 #include "debug.h"
+#include "util.h"
 
 static int input_fd;
 
@@ -414,7 +415,7 @@ ssize_t trace_report(int fd, struct trace_event *tevent, bool __repipe)
 		return -1;
 	}
 	file_bigendian = buf[0];
-	host_bigendian = bigendian();
+	host_bigendian = host_is_bigendian() ? 1 : 0;
 
 	if (trace_event__init(tevent)) {
 		pr_debug("trace_event__init failed");

tools/perf/util/trace-event.h

@@ -27,8 +27,6 @@ trace_event__tp_format(const char *sys, const char *name);
 
 struct tep_event *trace_event__tp_format_id(int id);
 
-int bigendian(void);
-
 void event_format__fprintf(struct tep_event *event,
 			   int cpu, void *data, int size, FILE *fp);
 

tools/perf/util/util.h

@@ -94,4 +94,23 @@ int do_realloc_array_as_needed(void **arr, size_t *arr_sz, size_t x,
 		0;						\
 	})
 
+static inline bool host_is_bigendian(void)
+{
+#ifdef __BYTE_ORDER__
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+	return false;
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+	return true;
+#else
+#error "Unrecognized __BYTE_ORDER__"
+#endif
+#else /* !__BYTE_ORDER__ */
+	unsigned char str[] = { 0x1, 0x2, 0x3, 0x4, 0x0, 0x0, 0x0, 0x0};
+	unsigned int *ptr;
+
+	ptr = (unsigned int *)(void *)str;
+	return *ptr == 0x01020304;
+#endif
+}
+
 #endif /* __PERF_UTIL_H */