From 5cde1d8222a849256f684363f38a6423dea9be74 Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Wed, 9 Dec 2020 14:12:58 -0700 Subject: [PATCH] Handle 128-bit constants for fixed point In some cases, GNAT can emit 128-bit constants for fixed-point types. This patch changes gdb to handle this scenario, by changing the low-level rational-reading functions in dwarf2/read.c to work directly with gdb_mpz values. (I'm not sure offhand if these 128-bit patches have gone into upstream GCC yet -- but they will eventually, and meanwhile I think it should be clear that this patch is otherwise harmless.) gdb/ChangeLog 2020-12-09 Tom Tromey * dwarf2/read.c (get_dwarf2_rational_constant): Change "numerator" and "denominator" to gdb_mpz. Handle block forms. (get_dwarf2_unsigned_rational_constant): Change "numerator" and "denominator" to gdb_mpz. (finish_fixed_point_type): Update. (has_zero_over_zero_small_attribute): Update. --- gdb/ChangeLog | 9 ++++++ gdb/dwarf2/read.c | 82 +++++++++++++++++++++++++++-------------------- 2 files changed, 57 insertions(+), 34 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 6c76405458a..4236e8c7e3b 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,12 @@ +2020-12-09 Tom Tromey + + * dwarf2/read.c (get_dwarf2_rational_constant): Change "numerator" + and "denominator" to gdb_mpz. Handle block forms. + (get_dwarf2_unsigned_rational_constant): Change "numerator" and + "denominator" to gdb_mpz. + (finish_fixed_point_type): Update. + (has_zero_over_zero_small_attribute): Update. + 2020-12-09 Tom Tromey * expprint.c (op_name): Update. diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c index 9468b9144e6..2bf14535f05 100644 --- a/gdb/dwarf2/read.c +++ b/gdb/dwarf2/read.c @@ -18194,7 +18194,7 @@ read_typedef (struct die_info *die, struct dwarf2_cu *cu) static void get_dwarf2_rational_constant (struct die_info *die, struct dwarf2_cu *cu, - LONGEST *numerator, LONGEST *denominator) + gdb_mpz *numerator, gdb_mpz *denominator) { struct attribute *num_attr, *denom_attr; @@ -18211,8 +18211,25 @@ get_dwarf2_rational_constant (struct die_info *die, struct dwarf2_cu *cu, if (num_attr == nullptr || denom_attr == nullptr) return; - *numerator = num_attr->constant_value (1); - *denominator = denom_attr->constant_value (1); + if (num_attr->form_is_block ()) + { + dwarf_block *blk = num_attr->as_block (); + mpz_import (numerator->val, blk->size, + bfd_big_endian (cu->per_objfile->objfile->obfd) ? 1 : -1, + 1, 0, 0, blk->data); + } + else + *numerator = gdb_mpz (num_attr->constant_value (1)); + + if (denom_attr->form_is_block ()) + { + dwarf_block *blk = denom_attr->as_block (); + mpz_import (denominator->val, blk->size, + bfd_big_endian (cu->per_objfile->objfile->obfd) ? 1 : -1, + 1, 0, 0, blk->data); + } + else + *denominator = gdb_mpz (denom_attr->constant_value (1)); } /* Same as get_dwarf2_rational_constant, but extracting an unsigned @@ -18224,25 +18241,26 @@ get_dwarf2_rational_constant (struct die_info *die, struct dwarf2_cu *cu, static void get_dwarf2_unsigned_rational_constant (struct die_info *die, struct dwarf2_cu *cu, - ULONGEST *numerator, - ULONGEST *denominator) + gdb_mpz *numerator, + gdb_mpz *denominator) { - LONGEST num = 1, denom = 1; + gdb_mpz num (1); + gdb_mpz denom (1); get_dwarf2_rational_constant (die, cu, &num, &denom); - if (num < 0 && denom < 0) + if (mpz_sgn (num.val) == -1 && mpz_sgn (denom.val) == -1) { - num = -num; - denom = -denom; + mpz_neg (num.val, num.val); + mpz_neg (denom.val, denom.val); } - else if (num < 0) + else if (mpz_sgn (num.val) == -1) { complaint (_("unexpected negative value for DW_AT_GNU_numerator" " in DIE at %s"), sect_offset_str (die->sect_off)); return; } - else if (denom < 0) + else if (mpz_sgn (denom.val) == -1) { complaint (_("unexpected negative value for DW_AT_GNU_denominator" " in DIE at %s"), @@ -18250,8 +18268,8 @@ get_dwarf2_unsigned_rational_constant (struct die_info *die, return; } - *numerator = num; - *denominator = denom; + *numerator = std::move (num); + *denominator = std::move (denom); } /* Assuming DIE corresponds to a fixed point type, finish the creation @@ -18263,14 +18281,6 @@ finish_fixed_point_type (struct type *type, struct die_info *die, struct dwarf2_cu *cu) { struct attribute *attr; - /* Numerator and denominator of our fixed-point type's scaling factor. - The default is a scaling factor of 1, which we use as a fallback - when we are not able to decode it (problem with the debugging info, - unsupported forms, bug in GDB, etc...). Using that as the default - allows us to at least print the unscaled value, which might still - be useful to a user. */ - ULONGEST scale_num = 1; - ULONGEST scale_denom = 1; gdb_assert (type->code () == TYPE_CODE_FIXED_POINT && TYPE_SPECIFIC_FIELD (type) == TYPE_SPECIFIC_FIXED_POINT); @@ -18281,6 +18291,15 @@ finish_fixed_point_type (struct type *type, struct die_info *die, if (!attr) attr = dwarf2_attr (die, DW_AT_small, cu); + /* Numerator and denominator of our fixed-point type's scaling factor. + The default is a scaling factor of 1, which we use as a fallback + when we are not able to decode it (problem with the debugging info, + unsupported forms, bug in GDB, etc...). Using that as the default + allows us to at least print the unscaled value, which might still + be useful to a user. */ + gdb_mpz scale_num (1); + gdb_mpz scale_denom (1); + if (attr == nullptr) { /* Scaling factor not found. Assume a scaling factor of 1, @@ -18292,16 +18311,16 @@ finish_fixed_point_type (struct type *type, struct die_info *die, else if (attr->name == DW_AT_binary_scale) { LONGEST scale_exp = attr->constant_value (0); - ULONGEST *num_or_denom = scale_exp > 0 ? &scale_num : &scale_denom; + gdb_mpz *num_or_denom = scale_exp > 0 ? &scale_num : &scale_denom; - *num_or_denom = 1 << std::abs (scale_exp); + mpz_mul_2exp (num_or_denom->val, num_or_denom->val, std::abs (scale_exp)); } else if (attr->name == DW_AT_decimal_scale) { LONGEST scale_exp = attr->constant_value (0); - ULONGEST *num_or_denom = scale_exp > 0 ? &scale_num : &scale_denom; + gdb_mpz *num_or_denom = scale_exp > 0 ? &scale_num : &scale_denom; - *num_or_denom = uinteger_pow (10, std::abs (scale_exp)); + mpz_ui_pow_ui (num_or_denom->val, 10, std::abs (scale_exp)); } else if (attr->name == DW_AT_small) { @@ -18326,13 +18345,8 @@ finish_fixed_point_type (struct type *type, struct die_info *die, } gdb_mpq &scaling_factor = type->fixed_point_info ().scaling_factor; - - gdb_mpz tmp_z (scale_num); - mpz_set (mpq_numref (scaling_factor.val), tmp_z.val); - - tmp_z = scale_denom; - mpz_set (mpq_denref (scaling_factor.val), tmp_z.val); - + mpz_set (mpq_numref (scaling_factor.val), scale_num.val); + mpz_set (mpq_denref (scaling_factor.val), scale_denom.val); mpq_canonicalize (scaling_factor.val); } @@ -18398,9 +18412,9 @@ has_zero_over_zero_small_attribute (struct die_info *die, if (scale_die->tag != DW_TAG_constant) return false; - LONGEST num = 1, denom = 1; + gdb_mpz num (1), denom (1); get_dwarf2_rational_constant (scale_die, cu, &num, &denom); - return (num == 0 && denom == 0); + return mpz_sgn (num.val) == 0 && mpz_sgn (denom.val) == 0; } /* Initialise and return a floating point type of size BITS suitable for -- 2.30.2