The die_collect_vars() is to find all variable information in the scope
including function parameters. The struct die_var_type is to save the
type of the variable with the location (reg and offset) as well as where
it's defined in the code (addr).
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/util/dwarf-aux.c | 60 +++++++++++++++++++++++++++++++++++++
tools/perf/util/dwarf-aux.h | 17 +++++++++++
2 files changed, 77 insertions(+)
diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c
index 093d7e82b333..16e63d8caf83 100644
--- a/tools/perf/util/dwarf-aux.c
+++ b/tools/perf/util/dwarf-aux.c
@@ -1545,6 +1545,66 @@ int die_get_cfa(Dwarf *dwarf, u64 pc, int *preg, int *poffset)
return -1;
}
+static int __die_collect_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 && tag != DW_TAG_formal_parameter)
+ return DIE_FIND_CB_SIBLING;
+
+ if (dwarf_attr(die_mem, DW_AT_location, &attr) == NULL)
+ return DIE_FIND_CB_SIBLING;
+
+ /*
+ * Only collect the first location as it can reconstruct the
+ * remaining state by following the instructions.
+ * start = 0 means it covers the whole range.
+ */
+ if (dwarf_getlocations(&attr, 0, &base, &start, &end, &ops, &nops) <= 0)
+ 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 = start;
+ vt->reg = reg_from_dwarf_op(ops);
+ vt->offset = offset_from_dwarf_op(ops);
+ vt->next = *var_types;
+ *var_types = vt;
+
+ return DIE_FIND_CB_SIBLING;
+}
+
+/**
+ * die_collect_vars - Save all variables and parameters
+ * @sc_die: a scope DIE
+ * @var_types: a pointer to save the resulting list
+ *
+ * Save all variables and parameters in the @sc_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_vars(Dwarf_Die *sc_die, struct die_var_type **var_types)
+{
+ Dwarf_Die die_mem;
+
+ die_find_child(sc_die, __die_collect_vars_cb, (void *)var_types, &die_mem);
+}
+
#endif
/*
diff --git a/tools/perf/util/dwarf-aux.h b/tools/perf/util/dwarf-aux.h
index dc7e98678216..d0ef41738abd 100644
--- a/tools/perf/util/dwarf-aux.h
+++ b/tools/perf/util/dwarf-aux.h
@@ -135,6 +135,15 @@ void die_skip_prologue(Dwarf_Die *sp_die, Dwarf_Die *cu_die,
/* Get the list of including scopes */
int die_get_scopes(Dwarf_Die *cu_die, Dwarf_Addr pc, Dwarf_Die **scopes);
+/* Variable type information */
+struct die_var_type {
+ struct die_var_type *next;
+ u64 die_off;
+ u64 addr;
+ int reg;
+ int offset;
+};
+
#ifdef HAVE_DWARF_GETLOCATIONS_SUPPORT
/* Get byte offset range of given variable DIE */
@@ -153,6 +162,9 @@ Dwarf_Die *die_find_variable_by_addr(Dwarf_Die *sc_die, Dwarf_Addr pc,
/* Get the frame base information from CFA */
int die_get_cfa(Dwarf *dwarf, u64 pc, int *preg, int *poffset);
+/* Save all variables and parameters in this scope */
+void die_collect_vars(Dwarf_Die *sc_die, struct die_var_type **var_types);
+
#else /* HAVE_DWARF_GETLOCATIONS_SUPPORT */
static inline int die_get_var_range(Dwarf_Die *sp_die __maybe_unused,
@@ -187,6 +199,11 @@ static inline int die_get_cfa(Dwarf *dwarf __maybe_unused, u64 pc __maybe_unused
return -1;
}
+static inline void die_collect_vars(Dwarf_Die *sc_die __maybe_unused,
+ struct die_var_type **var_types __maybe_unused)
+{
+}
+
#endif /* HAVE_DWARF_GETLOCATIONS_SUPPORT */
#endif /* _DWARF_AUX_H */
--
2.42.0.655.g421f12c284-goog
|