dwarf_loader: Initial support for DW_TAG_template_type_param tag

We don't really need to pretty print these, as the names of the classes
already come with it, for instance:

  ⬢[acme@toolbox [email protected]]$ pdwtags popup.cpp.o  | grep ^'struct integral_constant' -A11
  die__process_class: tag not supported 0x30 (template_value_parameter) at <5f0>!
  die__process_function: tag not supported 0x2f (template_type_parameter) at <1417>!
  die__process_class: tag not supported 0x4107 (GNU_template_parameter_pack) at <f1d8>!
  die__process_function: tag not supported 0x4108 (GNU_formal_parameter_pack) at <69aea>!
  struct integral_constant<bool, true> {
  	typedef bool value_type;

  	value_type operator std::integral_constant<bool, true>::value_type(const struct integral_constant<bool, true>  *);

  	value_type operator()(const struct integral_constant<bool, true>  *);

  	/* size: 1, cachelines: 0, members: 0 */
  	/* padding: 1 */
  	/* last cacheline: 1 bytes */
  }; /* size: 0 */
  --
  struct integral_constant<bool, false> {
  	typedef bool value_type;

  	value_type operator std::integral_constant<bool, false>::value_type(const struct integral_constant<bool, false>  *);

  	value_type operator()(const struct integral_constant<bool, false>  *);

  	/* size: 1, cachelines: 0, members: 0 */
  	/* padding: 1 */
  	/* last cacheline: 1 bytes */
  }; /* size: 0 */
  ⬢[acme@toolbox [email protected]]$

But lets collect this info, that only shows up in C++ (maybe other
languages, Rust?), we'll end up using it maybe for using them for
looking up all templates, or all templates of a given type or value,
etc.

I'll do the same for DW_TAG_template_value_parameter and support both in
DW_TAG_subprogram.

DW_TAG_GNU_template_parameter_pack must be some variation on this
theme...

Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

Author: acmel

dwarf_loader.c

@@ -1082,6 +1082,18 @@ static void arch__set_register_params(const GElf_Ehdr *ehdr, struct cu *cu)
 	}
 }
 
+static struct template_type_param *template_type_param__new(Dwarf_Die *die, struct cu *cu, struct conf_load *conf)
+{
+	struct template_type_param *ttparm = tag__alloc(cu, sizeof(*ttparm));
+
+	if (ttparm != NULL) {
+		tag__init(&ttparm->tag, cu, die);
+		ttparm->name = attr_string(die, DW_AT_name, conf);
+	}
+
+	return ttparm;
+}
+
 static struct parameter *parameter__new(Dwarf_Die *die, struct cu *cu,
 					struct conf_load *conf, int param_idx)
 {
@@ -1800,7 +1812,6 @@ static int die__process_class(Dwarf_Die *die, struct type *class,
 		case DW_TAG_GNU_template_parameter_pack:
 		case DW_TAG_GNU_template_template_param:
 #endif
-		case DW_TAG_template_type_parameter:
 		case DW_TAG_template_value_parameter:
 			/*
 			 * FIXME: probably we'll have to attach this as a list of
@@ -1811,6 +1822,15 @@ static int die__process_class(Dwarf_Die *die, struct type *class,
 			 */
 			tag__print_not_supported(die);
 			continue;
+		case DW_TAG_template_type_parameter: {
+			struct template_type_param *ttparm = template_type_param__new(die, cu, conf);
+
+			if (ttparm == NULL)
+				return -ENOMEM;
+
+			type__add_template_type_param(class, ttparm);
+			continue;
+		}
 		case DW_TAG_inheritance:
 		case DW_TAG_member: {
 			struct class_member *member = class_member__new(die, cu, is_union, conf);

dwarves.c

@@ -365,6 +365,7 @@ void __type__init(struct type *type)
 {
 	INIT_LIST_HEAD(&type->node);
 	INIT_LIST_HEAD(&type->type_enum);
+	INIT_LIST_HEAD(&type->template_type_params);
 	type->sizeof_member = NULL;
 	type->member_prefix = NULL;
 	type->member_prefix_len = 0;
@@ -1329,6 +1330,11 @@ void type__add_member(struct type *type, struct class_member *member)
 	namespace__add_tag(&type->namespace, &member->tag);
 }
 
+void type__add_template_type_param(struct type *type, struct template_type_param *ttparam)
+{
+	list_add_tail(&ttparam->tag.node, &type->template_type_params);
+}
+
 struct class_member *type__last_member(struct type *type)
 {
 	struct class_member *pos;

dwarves.h

@@ -1121,6 +1121,15 @@ static __pure inline int tag__is_class_member(const struct tag *tag)
 	return tag->tag == DW_TAG_member;
 }
 
+/* struct template_type_param - parameters to a template, stored in 'struct type'
+ */
+struct template_type_param {
+	struct tag	 tag;
+	const char	 *name;
+};
+
+void template_type_param__delete(struct template_type_param *ttparam);
+
 int tag__is_base_type(const struct tag *tag, const struct cu *cu);
 bool tag__is_array(const struct tag *tag, const struct cu *cu);
 
@@ -1172,6 +1181,7 @@ struct type {
 	uint8_t		 fwd_decl_emitted:1;
 	uint8_t		 resized:1;
 	uint8_t		 is_signed_enum:1;
+	struct list_head template_type_params;
 };
 
 void __type__init(struct type *type);
@@ -1289,6 +1299,8 @@ static inline struct class_member *class_member__next(struct class_member *membe
 	list_for_each_entry_safe_reverse(pos, n, &(type)->namespace.tags, tag.node)
 
 void type__add_member(struct type *type, struct class_member *member);
+void type__add_template_type_param(struct type *type, struct template_type_param *ttparm);
+
 struct class_member *
 	type__find_first_biggest_size_base_type_member(struct type *type,
 						       const struct cu *cu);