core: Allow the loaders to advertise features they have

For instance, DWARF has DW_AT_alignment, and some output features
require that, so let loaders advertise such things, next patch will use
this info.

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

dwarf_loader.c

@@ -2528,4 +2528,5 @@ struct debug_fmt_ops dwarf__ops = {
 	.tag__decl_file	     = dwarf_tag__decl_file,
 	.tag__decl_line	     = dwarf_tag__decl_line,
 	.tag__orig_id	     = dwarf_tag__orig_id,
+	.has_alignment_info  = true,
 };

dwarves.c

@@ -1682,6 +1682,9 @@ int cus__load_file(struct cus *cus, struct conf_load *conf,
 			if (loader == -1)
 				break;
 
+			if (conf->conf_fprintf)
+				conf->conf_fprintf->has_alignment_info = debug_fmt_table[loader]->has_alignment_info;
+
 			err = 0;
 			if (debug_fmt_table[loader]->load_file(cus, conf,
 							       filename) == 0)
@@ -1698,6 +1701,8 @@ int cus__load_file(struct cus *cus, struct conf_load *conf,
 	}
 
 	while (debug_fmt_table[i] != NULL) {
+		if (conf->conf_fprintf)
+			conf->conf_fprintf->has_alignment_info = debug_fmt_table[i]->has_alignment_info;
 		if (debug_fmt_table[i]->load_file(cus, conf, filename) == 0)
 			return 0;
 		++i;

dwarves.h

@@ -33,6 +33,8 @@ enum load_steal_kind {
  */
 typedef uint32_t type_id_t;
 
+struct conf_fprintf;
+
 /** struct conf_load - load configuration
  * @extra_dbg_info - keep original debugging format extra info
  *		     (e.g. DWARF's decl_{line,file}, id, etc)
@@ -47,6 +49,7 @@ struct conf_load {
 	bool			extra_dbg_info;
 	bool			fixup_silly_bitfields;
 	bool			get_addr_info;
+	struct conf_fprintf	*conf_fprintf;
 };
 
 /** struct conf_fprintf - hints to the __fprintf routines
@@ -69,6 +72,7 @@ struct conf_fprintf {
 	uint8_t    rel_offset:1;
 	uint8_t	   emit_stats:1;
 	uint8_t	   suppress_comments:1;
+	uint8_t	   has_alignment_info:1;
 	uint8_t	   suppress_aligned_attribute:1;
 	uint8_t	   suppress_offset_comment:1;
 	uint8_t	   show_decl_info:1;
@@ -180,6 +184,7 @@ struct debug_fmt_ops {
 					      const struct cu *cu);
 	const char	   *(*strings__ptr)(const struct cu *cu, strings_t s);
 	void		   (*cu__delete)(struct cu *cu);
+	bool		   has_alignment_info;
 };
 
 struct cu {

pahole.c

@@ -62,7 +62,9 @@ static struct conf_fprintf conf = {
 	.emit_stats = 1,
 };
 
-static struct conf_load conf_load;
+static struct conf_load conf_load = {
+	.conf_fprintf = &conf,
+};
 
 struct structure {
 	struct list_head  node;

pdwtags.c

@@ -81,6 +81,7 @@ static enum load_steal_kind pdwtags_stealer(struct cu *cu,
 
 static struct conf_load pdwtags_conf_load = {
 	.steal = pdwtags_stealer,
+	.conf_fprintf = &conf,
 };
 
 /* Name and version of program.  */

pfunct.c

@@ -36,7 +36,9 @@ static uint64_t addr;
 
 static struct conf_fprintf conf;
 
-static struct conf_load conf_load;
+static struct conf_load conf_load = {
+	.conf_fprintf = &conf,
+};
 
 struct fn_stats {
 	struct list_head node;