diff options
Diffstat (limited to 'tools/perf/util/dwarf-aux.c')
| -rw-r--r-- | tools/perf/util/dwarf-aux.c | 202 |
1 files changed, 139 insertions, 63 deletions
diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c index 279112606..f93e57e2f 100644 --- a/tools/perf/util/dwarf-aux.c +++ b/tools/perf/util/dwarf-aux.c @@ -1136,6 +1136,68 @@ int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf) return ret < 0 ? ret : strbuf_addf(buf, "\t%s", dwarf_diename(vr_die)); } +#if defined(HAVE_DWARF_GETLOCATIONS_SUPPORT) || defined(HAVE_DWARF_CFI_SUPPORT) +static int reg_from_dwarf_op(Dwarf_Op *op) +{ + switch (op->atom) { + case DW_OP_reg0 ... DW_OP_reg31: + return op->atom - DW_OP_reg0; + case DW_OP_breg0 ... DW_OP_breg31: + return op->atom - DW_OP_breg0; + case DW_OP_regx: + case DW_OP_bregx: + return op->number; + default: + break; + } + return -1; +} + +static int offset_from_dwarf_op(Dwarf_Op *op) +{ + switch (op->atom) { + case DW_OP_reg0 ... DW_OP_reg31: + case DW_OP_regx: + return 0; + case DW_OP_breg0 ... DW_OP_breg31: + return op->number; + case DW_OP_bregx: + return op->number2; + default: + break; + } + return -1; +} + +static bool check_allowed_ops(Dwarf_Op *ops, size_t nops) +{ + /* The first op is checked separately */ + ops++; + nops--; + + /* + * It needs to make sure if the location expression matches to the given + * register and offset exactly. Thus it rejects any complex expressions + * and only allows a few of selected operators that doesn't change the + * location. + */ + while (nops) { + switch (ops->atom) { + case DW_OP_stack_value: + case DW_OP_deref_size: + case DW_OP_deref: + case DW_OP_piece: + break; + default: + return false; + } + ops++; + nops--; + } + return true; +} +#endif /* HAVE_DWARF_GETLOCATIONS_SUPPORT || HAVE_DWARF_CFI_SUPPORT */ + #ifdef HAVE_DWARF_GETLOCATIONS_SUPPORT /** * die_get_var_innermost_scope - Get innermost scope range of given variable DIE @@ -1280,7 +1342,7 @@ struct find_var_data { #define DWARF_OP_DIRECT_REGS 32 static bool match_var_offset(Dwarf_Die *die_mem, struct find_var_data *data, - u64 addr_offset, u64 addr_type) + u64 addr_offset, u64 addr_type, bool is_pointer) { Dwarf_Die type_die; Dwarf_Word size; @@ -1294,6 +1356,12 @@ static bool match_var_offset(Dwarf_Die *die_mem, struct find_var_data *data, if (die_get_real_type(die_mem, &type_die) == NULL) return false; + if (is_pointer && dwarf_tag(&type_die) == DW_TAG_pointer_type) { + /* Get the target type of the pointer */ + if (die_get_real_type(&type_die, &type_die) == NULL) + return false; + } + if (dwarf_aggregate_size(&type_die, &size) < 0) return false; @@ -1305,34 +1373,6 @@ static bool match_var_offset(Dwarf_Die *die_mem, struct find_var_data *data, return true; } -static bool check_allowed_ops(Dwarf_Op *ops, size_t nops) -{ - /* The first op is checked separately */ - ops++; - nops--; - - /* - * It needs to make sure if the location expression matches to the given - * register and offset exactly. Thus it rejects any complex expressions - * and only allows a few of selected operators that doesn't change the - * location. - */ - while (nops) { - switch (ops->atom) { - case DW_OP_stack_value: - case DW_OP_deref_size: - case DW_OP_deref: - case DW_OP_piece: - break; - default: - return false; - } - ops++; - nops--; - } - return true; -} - /* Only checks direct child DIEs in the given scope. */ static int __die_find_var_reg_cb(Dwarf_Die *die_mem, void *arg) { @@ -1361,31 +1401,38 @@ static int __die_find_var_reg_cb(Dwarf_Die *die_mem, void *arg) 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)) + match_var_offset(die_mem, data, data->offset, ops->number, + /*is_pointer=*/false)) return DIE_FIND_CB_END; /* Only match with a simple case */ if (data->reg < DWARF_OP_DIRECT_REGS) { /* pointer variables saved in a register 0 to 31 */ if (ops->atom == (DW_OP_reg0 + data->reg) && - check_allowed_ops(ops, nops)) + check_allowed_ops(ops, nops) && + match_var_offset(die_mem, data, data->offset, 0, + /*is_pointer=*/true)) return DIE_FIND_CB_END; /* Local variables accessed by a register + offset */ if (ops->atom == (DW_OP_breg0 + data->reg) && check_allowed_ops(ops, nops) && - match_var_offset(die_mem, data, data->offset, ops->number)) + match_var_offset(die_mem, data, data->offset, ops->number, + /*is_pointer=*/false)) return DIE_FIND_CB_END; } else { /* pointer variables saved in a register 32 or above */ if (ops->atom == DW_OP_regx && ops->number == data->reg && - check_allowed_ops(ops, nops)) + check_allowed_ops(ops, nops) && + match_var_offset(die_mem, data, data->offset, 0, + /*is_pointer=*/true)) return DIE_FIND_CB_END; /* Local variables accessed by a register + offset */ if (ops->atom == DW_OP_bregx && data->reg == ops->number && check_allowed_ops(ops, nops) && - match_var_offset(die_mem, data, data->offset, ops->number2)) + match_var_offset(die_mem, data, data->offset, ops->number2, + /*is_poitner=*/false)) return DIE_FIND_CB_END; } } @@ -1447,7 +1494,8 @@ static int __die_find_var_addr_cb(Dwarf_Die *die_mem, void *arg) continue; if (check_allowed_ops(ops, nops) && - match_var_offset(die_mem, data, data->addr, ops->number)) + match_var_offset(die_mem, data, data->addr, ops->number, + /*is_pointer=*/false)) return DIE_FIND_CB_END; } return DIE_FIND_CB_SIBLING; @@ -1479,41 +1527,69 @@ Dwarf_Die *die_find_variable_by_addr(Dwarf_Die *sc_die, Dwarf_Addr pc, *offset = data.offset; return result; } -#endif /* HAVE_DWARF_GETLOCATIONS_SUPPORT */ -#ifdef HAVE_DWARF_CFI_SUPPORT -static int reg_from_dwarf_op(Dwarf_Op *op) +static int __die_collect_vars_cb(Dwarf_Die *die_mem, void *arg) { - switch (op->atom) { - case DW_OP_reg0 ... DW_OP_reg31: - return op->atom - DW_OP_reg0; - case DW_OP_breg0 ... DW_OP_breg31: - return op->atom - DW_OP_breg0; - case DW_OP_regx: - case DW_OP_bregx: - return op->number; - default: - break; - } - return -1; + 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; } -static int offset_from_dwarf_op(Dwarf_Op *op) +/** + * 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) { - switch (op->atom) { - case DW_OP_reg0 ... DW_OP_reg31: - case DW_OP_regx: - return 0; - case DW_OP_breg0 ... DW_OP_breg31: - return op->number; - case DW_OP_bregx: - return op->number2; - default: - break; - } - return -1; + Dwarf_Die die_mem; + + die_find_child(sc_die, __die_collect_vars_cb, (void *)var_types, &die_mem); } +#endif /* HAVE_DWARF_GETLOCATIONS_SUPPORT */ +#ifdef HAVE_DWARF_CFI_SUPPORT /** * die_get_cfa - Get frame base information * @dwarf: a Dwarf info |