1 files changed, 230 insertions, 10 deletions

diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c
index f93e57e2fc..44ef968a7a 100644
--- a/tools/perf/util/dwarf-aux.c
+++ b/tools/perf/util/dwarf-aux.c
@@ -9,6 +9,7 @@
 #include <stdlib.h>
 #include "debug.h"
 #include "dwarf-aux.h"
+#include "dwarf-regs.h"
 #include "strbuf.h"
 #include "string2.h"
 
@@ -696,6 +697,49 @@ Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
 	return die_mem;
 }
 
+static int __die_find_func_rettype_cb(Dwarf_Die *die_mem, void *data)
+{
+	const char *func_name;
+
+	if (dwarf_tag(die_mem) != DW_TAG_subprogram)
+		return DIE_FIND_CB_SIBLING;
+
+	func_name = dwarf_diename(die_mem);
+	if (func_name && !strcmp(func_name, data))
+		return DIE_FIND_CB_END;
+
+	return DIE_FIND_CB_SIBLING;
+}
+
+/**
+ * die_find_func_rettype - Search a return type of function
+ * @cu_die: a CU DIE
+ * @name: target function name
+ * @die_mem: a buffer for result DIE
+ *
+ * Search a non-inlined function which matches to @name and stores the
+ * return type of the function to @die_mem and returns it if found.
+ * Returns NULL if failed.  Note that it doesn't needs to find a
+ * definition of the function, so it doesn't match with address.
+ * Most likely, it can find a declaration at the top level.  Thus the
+ * callback function continues to sibling entries only.
+ */
+Dwarf_Die *die_find_func_rettype(Dwarf_Die *cu_die, const char *name,
+				 Dwarf_Die *die_mem)
+{
+	Dwarf_Die tmp_die;
+
+	cu_die = die_find_child(cu_die, __die_find_func_rettype_cb,
+				(void *)name, &tmp_die);
+	if (!cu_die)
+		return NULL;
+
+	if (die_get_real_type(&tmp_die, die_mem) == NULL)
+		return NULL;
+
+	return die_mem;
+}
+
 struct __instance_walk_param {
 	void    *addr;
 	int	(*callback)(Dwarf_Die *, void *);
@@ -1066,8 +1110,10 @@ int die_get_typename_from_type(Dwarf_Die *type_die, struct strbuf *buf)
 	const char *tmp = "";
 
 	tag = dwarf_tag(type_die);
-	if (tag == DW_TAG_array_type || tag == DW_TAG_pointer_type)
+	if (tag == DW_TAG_pointer_type)
 		tmp = "*";
+	else if (tag == DW_TAG_array_type)
+		tmp = "[]";
 	else if (tag == DW_TAG_subroutine_type) {
 		/* Function pointer */
 		return strbuf_add(buf, "(function_type)", 15);
@@ -1147,6 +1193,8 @@ static int reg_from_dwarf_op(Dwarf_Op *op)
 	case DW_OP_regx:
 	case DW_OP_bregx:
 		return op->number;
+	case DW_OP_fbreg:
+		return DWARF_REG_FB;
 	default:
 		break;
 	}
@@ -1160,6 +1208,7 @@ static int offset_from_dwarf_op(Dwarf_Op *op)
 	case DW_OP_regx:
 		return 0;
 	case DW_OP_breg0 ... DW_OP_breg31:
+	case DW_OP_fbreg:
 		return op->number;
 	case DW_OP_bregx:
 		return op->number2;
@@ -1353,6 +1402,9 @@ static bool match_var_offset(Dwarf_Die *die_mem, struct find_var_data *data,
 		return true;
 	}
 
+	if (addr_offset < addr_type)
+		return false;
+
 	if (die_get_real_type(die_mem, &type_die) == NULL)
 		return false;
 
@@ -1399,7 +1451,6 @@ static int __die_find_var_reg_cb(Dwarf_Die *die_mem, void *arg)
 
 		/* Local variables accessed using frame base register */
 		if (data->is_fbreg && ops->atom == DW_OP_fbreg &&
-		    data->offset >= (int)ops->number &&
 		    check_allowed_ops(ops, nops) &&
 		    match_var_offset(die_mem, data, data->offset, ops->number,
 				     /*is_pointer=*/false))
@@ -1490,9 +1541,6 @@ static int __die_find_var_addr_cb(Dwarf_Die *die_mem, void *arg)
 		if (ops->atom != DW_OP_addr)
 			continue;
 
-		if (data->addr < ops->number)
-			continue;
-
 		if (check_allowed_ops(ops, nops) &&
 		    match_var_offset(die_mem, data, data->addr, ops->number,
 				     /*is_pointer=*/false))
@@ -1504,7 +1552,6 @@ static int __die_find_var_addr_cb(Dwarf_Die *die_mem, void *arg)
 /**
  * die_find_variable_by_addr - Find variable located at given address
  * @sc_die: a scope DIE
- * @pc: the program address to find
  * @addr: the data address to find
  * @die_mem: a buffer to save the resulting DIE
  * @offset: the offset in the resulting type
@@ -1512,12 +1559,10 @@ static int __die_find_var_addr_cb(Dwarf_Die *die_mem, void *arg)
  * Find the variable DIE located at the given address (in PC-relative mode).
  * This is usually for global variables.
  */
-Dwarf_Die *die_find_variable_by_addr(Dwarf_Die *sc_die, Dwarf_Addr pc,
-				     Dwarf_Addr addr, Dwarf_Die *die_mem,
-				     int *offset)
+Dwarf_Die *die_find_variable_by_addr(Dwarf_Die *sc_die, Dwarf_Addr addr,
+				     Dwarf_Die *die_mem, int *offset)
 {
 	struct find_var_data data = {
-		.pc = pc,
 		.addr = addr,
 	};
 	Dwarf_Die *result;
@@ -1587,6 +1632,68 @@ void die_collect_vars(Dwarf_Die *sc_die, struct die_var_type **var_types)
 
 	die_find_child(sc_die, __die_collect_vars_cb, (void *)var_types, &die_mem);
 }
+
+static int __die_collect_global_vars_cb(Dwarf_Die *die_mem, void *arg)
+{
+	struct die_var_type **var_types = arg;
+	Dwarf_Die type_die;
+	int tag = dwarf_tag(die_mem);
+	Dwarf_Attribute attr;
+	Dwarf_Addr base, start, end;
+	Dwarf_Op *ops;
+	size_t nops;
+	struct die_var_type *vt;
+
+	if (tag != DW_TAG_variable)
+		return DIE_FIND_CB_SIBLING;
+
+	if (dwarf_attr(die_mem, DW_AT_location, &attr) == NULL)
+		return DIE_FIND_CB_SIBLING;
+
+	/* Only collect the location with an absolute address. */
+	if (dwarf_getlocations(&attr, 0, &base, &start, &end, &ops, &nops) <= 0)
+		return DIE_FIND_CB_SIBLING;
+
+	if (ops->atom != DW_OP_addr)
+		return DIE_FIND_CB_SIBLING;
+
+	if (!check_allowed_ops(ops, nops))
+		return DIE_FIND_CB_SIBLING;
+
+	if (die_get_real_type(die_mem, &type_die) == NULL)
+		return DIE_FIND_CB_SIBLING;
+
+	vt = malloc(sizeof(*vt));
+	if (vt == NULL)
+		return DIE_FIND_CB_END;
+
+	vt->die_off = dwarf_dieoffset(&type_die);
+	vt->addr = ops->number;
+	vt->reg = -1;
+	vt->offset = 0;
+	vt->next = *var_types;
+	*var_types = vt;
+
+	return DIE_FIND_CB_SIBLING;
+}
+
+/**
+ * die_collect_global_vars - Save all global variables
+ * @cu_die: a CU DIE
+ * @var_types: a pointer to save the resulting list
+ *
+ * Save all global variables in the @cu_die and save them to @var_types.
+ * The @var_types is a singly-linked list containing type and location info.
+ * Actual type can be retrieved using dwarf_offdie() with 'die_off' later.
+ *
+ * Callers should free @var_types.
+ */
+void die_collect_global_vars(Dwarf_Die *cu_die, struct die_var_type **var_types)
+{
+	Dwarf_Die die_mem;
+
+	die_find_child(cu_die, __die_collect_global_vars_cb, (void *)var_types, &die_mem);
+}
 #endif /* HAVE_DWARF_GETLOCATIONS_SUPPORT */
 
 #ifdef HAVE_DWARF_CFI_SUPPORT
@@ -1855,3 +1962,116 @@ int die_get_scopes(Dwarf_Die *cu_die, Dwarf_Addr pc, Dwarf_Die **scopes)
 	*scopes = data.scopes;
 	return data.nr;
 }
+
+static int __die_find_member_offset_cb(Dwarf_Die *die_mem, void *arg)
+{
+	Dwarf_Die type_die;
+	Dwarf_Word size, loc;
+	Dwarf_Word offset = (long)arg;
+	int tag = dwarf_tag(die_mem);
+
+	if (tag != DW_TAG_member)
+		return DIE_FIND_CB_SIBLING;
+
+	/* Unions might not have location */
+	if (die_get_data_member_location(die_mem, &loc) < 0)
+		loc = 0;
+
+	if (offset == loc)
+		return DIE_FIND_CB_END;
+
+	if (die_get_real_type(die_mem, &type_die) == NULL) {
+		// TODO: add a pr_debug_dtp() later for this unlikely failure
+		return DIE_FIND_CB_SIBLING;
+	}
+
+	if (dwarf_aggregate_size(&type_die, &size) < 0)
+		size = 0;
+
+	if (loc < offset && offset < (loc + size))
+		return DIE_FIND_CB_END;
+
+	return DIE_FIND_CB_SIBLING;
+}
+
+/**
+ * die_get_member_type - Return type info of struct member
+ * @type_die: a type DIE
+ * @offset: offset in the type
+ * @die_mem: a buffer to save the resulting DIE
+ *
+ * This function returns a type of a member in @type_die where it's located at
+ * @offset if it's a struct.  For now, it just returns the first matching
+ * member in a union.  For other types, it'd return the given type directly
+ * if it's within the size of the type or NULL otherwise.
+ */
+Dwarf_Die *die_get_member_type(Dwarf_Die *type_die, int offset,
+			       Dwarf_Die *die_mem)
+{
+	Dwarf_Die *member;
+	Dwarf_Die mb_type;
+	int tag;
+
+	tag = dwarf_tag(type_die);
+	/* If it's not a compound type, return the type directly */
+	if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
+		Dwarf_Word size;
+
+		if (dwarf_aggregate_size(type_die, &size) < 0)
+			size = 0;
+
+		if ((unsigned)offset >= size)
+			return NULL;
+
+		*die_mem = *type_die;
+		return die_mem;
+	}
+
+	mb_type = *type_die;
+	/* TODO: Handle union types better? */
+	while (tag == DW_TAG_structure_type || tag == DW_TAG_union_type) {
+		member = die_find_child(&mb_type, __die_find_member_offset_cb,
+					(void *)(long)offset, die_mem);
+		if (member == NULL)
+			return NULL;
+
+		if (die_get_real_type(member, &mb_type) == NULL)
+			return NULL;
+
+		tag = dwarf_tag(&mb_type);
+
+		if (tag == DW_TAG_structure_type || tag == DW_TAG_union_type) {
+			Dwarf_Word loc;
+
+			/* Update offset for the start of the member struct */
+			if (die_get_data_member_location(member, &loc) == 0)
+				offset -= loc;
+		}
+	}
+	*die_mem = mb_type;
+	return die_mem;
+}
+
+/**
+ * die_deref_ptr_type - Return type info for pointer access
+ * @ptr_die: a pointer type DIE
+ * @offset: access offset for the pointer
+ * @die_mem: a buffer to save the resulting DIE
+ *
+ * This function follows the pointer in @ptr_die with given @offset
+ * and saves the resulting type in @die_mem.  If the pointer points
+ * a struct type, actual member at the offset would be returned.
+ */
+Dwarf_Die *die_deref_ptr_type(Dwarf_Die *ptr_die, int offset,
+			      Dwarf_Die *die_mem)
+{
+	Dwarf_Die type_die;
+
+	if (dwarf_tag(ptr_die) != DW_TAG_pointer_type)
+		return NULL;
+
+	if (die_get_real_type(ptr_die, &type_die) == NULL)
+		return NULL;
+
+	return die_get_member_type(&type_die, offset, die_mem);
+}