fprintf: Introduce struct to account holes in class member types

This will allow introducing a function to print info about holes in
member types, something that is only done today for the padding at the
end of such types.

This is how it is now:

  $ pahole task_struct |  grep "XXX last" -B2
  	struct sched_statistics    stats __attribute__((__aligned__(64))); /*   768   256 */

  	/* XXX last struct has 24 bytes of padding */
  --
  	struct prev_cputime        prev_cputime;         /*  2720    24 */

  	/* XXX last struct has 4 bytes of padding */
  --
  	struct posix_cputimers_work posix_cputimers_work; /*  2928    56 */

  	/* XXX last struct has 4 bytes of padding */
  --
  	struct syscall_user_dispatch syscall_dispatch;   /*  3224    32 */

  	/* XXX last struct has 7 bytes of padding */
  --
  	struct tlbflush_unmap_batch tlb_ubc;             /*  3976  1032 */

  	/* XXX last struct has 6 bytes of padding */
  --
  	struct timer_list          oom_reaper_timer;     /*  9056    40 */

  	/* XXX last struct has 4 bytes of padding */
  $

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 10 insertions, 6 deletions

diff --git a/dwarves_fprintf.c b/dwarves_fprintf.c
index ef8b82bd..cfee786a 100644
--- a/dwarves_fprintf.c
+++ b/dwarves_fprintf.c
@@ -1462,19 +1462,23 @@ out:
 	return printed;
 }
 
+struct member_types_holes {
+	uint16_t nr_paddings;
+	uint32_t sum_paddings;
+};
+
 static size_t __class__fprintf(struct class *class, const struct cu *cu,
 			       const struct conf_fprintf *conf, FILE *fp)
 {
 	struct type *type = &class->type;
 	size_t last_size = 0, size;
 	uint8_t newline = 0;
-	uint16_t nr_paddings = 0;
 	uint16_t nr_forced_alignments = 0, nr_forced_alignment_holes = 0;
 	uint32_t sum_forced_alignment_holes = 0;
 	uint32_t sum_bytes = 0, sum_bits = 0;
 	uint32_t sum_holes = 0;
-	uint32_t sum_paddings = 0;
 	uint32_t sum_bit_holes = 0;
+	struct member_types_holes member_types_holes = { 0, };
 	uint32_t cacheline = 0;
 	int size_diff = 0;
 	int first = 1;
@@ -1693,8 +1697,8 @@ static size_t __class__fprintf(struct class *class, const struct cu *cu,
 
 			padding = tclass->padding;
 			if (padding > 0) {
-				++nr_paddings;
-				sum_paddings += padding;
+				++member_types_holes.nr_paddings;
+				member_types_holes.sum_paddings += padding;
 				if (!newline++) {
 					fputc('\n', fp);
 					++printed;
@@ -1841,11 +1845,11 @@ static size_t __class__fprintf(struct class *class, const struct cu *cu,
 		printed += fprintf(fp, "%.*s/* padding: %u */\n",
 				   cconf.indent,
 				   tabs, class->padding);
-	if (nr_paddings > 0)
+	if (member_types_holes.nr_paddings > 0)
 		printed += fprintf(fp, "%.*s/* paddings: %u, sum paddings: "
 				   "%u */\n",
 				   cconf.indent, tabs,
-				   nr_paddings, sum_paddings);
+				   member_types_holes.nr_paddings, member_types_holes.sum_paddings);
 	if (class->bit_padding > 0)
 		printed += fprintf(fp, "%.*s/* bit_padding: %u bits */\n",
 				   cconf.indent, tabs,