It is not currently possible to cast some values to an rvaule
reference. This happens when simple scalar values are cast to an
rvalue reference of the same type, e.g.:
int global_var;
Then in GDB:
(gdb) p static_cast<int&&> (global_var)
Attempt to take address of value not located in memory.
Which is clearly silly.
The problem is that as part of the cast an intermediate value is
created within GDB that becomes an lval_none rather than the original
lval_memory. The casting logic basically goes like this:
The call tree that leads to the error looks like this:
value_cast
value_cast
value_ref
value_addr
error
The first value_cast call is casting the value for 'global_var' to
type 'int&&'. GDB spots that the target type is a reference, and so
calls value_cast again, this time casting 'global_var' to type 'int'.
We then call value_ref to convert the result of the second value_cast
into a reference.
Unfortunately, the second cast results in the value (for global_var)
changing from an lval_memory to an lval_none. This is because int to
int casting calls extract_unsigned_integer and then
value_from_longest.
In theory value_cast has a check at its head that should help in this
case, the code is:
if (value_type (arg2) == type)
return arg2;
However, this only works in some cases. In our case
'value_type (arg2)' will be an objfile owned type, while the type from
the expression parser 'int&&' will be gdbarch owned. The pointers
will not be equal, but the meaning of the type will be equal.
I did consider making the int to int casting case smarter, but this
obviously is only one example. We must also consider things like
float to float, or pointer to pointer....
So, I instead decided to try and make the initial check smarter.
Instead of a straight pointer comparison, I now propose that we use
types_deeply_equal. If this is true then we are casting something
back to its current type, in which case we can preserve the lval
setting by using value_copy.
gdb/ChangeLog:
* valops.c (value_cast): Call value_deeply_equal before performing
any cast.
gdb/testsuite/ChangeLog:
* gdb.cp/rvalue-ref-params.cc (f3): New function.
(f4): New function.
(global_int): New global variable.
(global_float): Likeiwse.
(main): Call both new functions.
* gdb.cp/rvalue-ref-params.exp: Add new tests.
The current_top_target function is a hidden dependency on the current
inferior. Since I'd like to slowly move towards reducing our dependency
on the global current state, remove this function and make callers use
current_inferior ()->top_target ()
There is no expected change in behavior, but this one step towards
making those callers use the inferior from their context, rather than
refer to the global current inferior.
gdb/ChangeLog:
* target.h (current_top_target): Remove, make callers use the
current inferior instead.
* target.c (current_top_target): Remove.
Change-Id: Iccd457036f84466cdaa3865aa3f9339a24ea001d
When building for 32-bit ARM, I ran into a couple build failures.
The first one seems to be caused by recent changes to warning switches,
leading to the following error:
--
In file included from gdb/coffread.c:35:0:
gdb/coffread.c: In function "void enter_linenos(file_ptr, int, int, objfile*)":
gdb/complaints.h:40:40: error: format "%ld" expects argument of type "long int", but argument 2 has type "file_ptr {aka long long int}" [-Werror=format=]
complaint_internal (FMT, ##__VA_ARGS__); \
^
gdb/coffread.c:1413:7: note: in expansion of macro "complaint"
complaint (_("Line number pointer %ld lower than start of line numbers"),
^~~~~~~~~
--
The other one is due to a narrowing conversion in valops.c:
--
gdb/valops.c: In function "value* value_assign(value*, value*)":
gdb/gdbtypes.h:1798:43: error: narrowing conversion of "type->type::length" from "ULONGEST {aka long long unsigned int}" to "size_t {aka unsigned int}" inside { } [-Werror=narrowing]
#define TYPE_LENGTH(thistype) (thistype)->length
~~~~~~~~~~~~^
gdb/valops.c:1252:9: note: in expansion of macro "TYPE_LENGTH"
TYPE_LENGTH (type)});
--
Fix both with the following patch. Validated with --enable-targets=all on
Ubuntu 18.04/20.04.
gdb/ChangeLog:
2021-01-21 Luis Machado <luis.machado@linaro.org>
* coffread.c (enter_linenos): Passing string to complaint.
* valops.c (value_assign): Make array view.
Testing showed that gdb was not correctly handling some fixed-point
binary operations correctly.
Addition and subtraction worked by casting the result to the type of
left hand operand. So, "fixed+int" had a different type -- and
different value -- from "int+fixed".
Furthermore, for multiplication and division, it does not make sense
to first cast both sides to the fixed-point type. For example, this
can prevent "f * 1" from yielding "f", if 1 is not in the domain of
"f". Instead, this patch changes gdb to use the value. (This is
somewhat different from Ada semantics, as those can yield a "universal
fixed point".)
This includes a new test case. It is only run in "minimal" mode, as
the old-style fixed point works differently, and is obsolete, so I
have no plans to change it.
gdb/ChangeLog
2021-01-06 Tom Tromey <tromey@adacore.com>
* ada-lang.c (ada_evaluate_subexp) <BINOP_ADD, BINOP_SUB>:
Do not cast result.
* valarith.c (fixed_point_binop): Handle multiplication
and division specially.
* valops.c (value_to_gdb_mpq): New function.
(value_cast_to_fixed_point): Use it.
gdb/testsuite/ChangeLog
2021-01-06 Tom Tromey <tromey@adacore.com>
* gdb.ada/fixed_points/pck.ads (Delta4): New constant.
(FP4_Type): New type.
(FP4_Var): New variable.
* gdb.ada/fixed_points/fixed_points.adb: Update.
* gdb.ada/fixed_points.exp: Add tests for binary operators.
This commits the result of running gdb/copyright.py as per our Start
of New Year procedure...
gdb/ChangeLog
Update copyright year range in copyright header of all GDB files.
get_discrete_bounds currently has three possible return values (see its
current doc for details). It appears that for all callers, it would be
sufficient to have a boolean "worked" / "didn't work" return value.
Change the return type of get_discrete_bounds to bool and adjust all
callers. Doing so simplifies the following patch.
gdb/ChangeLog:
* gdbtypes.h (get_discrete_bounds): Return bool, adjust all
callers.
* gdbtypes.c (get_discrete_bounds): Return bool.
Change-Id: Ie51feee23c75f0cd7939742604282d745db59172
This logically connects this function to the object it inspects.
gdb/ChangeLog:
* gdbtypes.h (struct type) <fixed_point_scaling_factor>: New method,
replacing fixed_point_scaling_factor. All callers updated
throughout this project.
(fixed_point_scaling_factor): Delete declaration.
* gdbtypes.c (type::fixed_point_scaling_factor): Replaces
fixed_point_scaling_factor. Adjust implementation accordingly.
This commit changes the interfaces of some of the methods declared
in gmp-utils to take a gdb::array_view of gdb_byte instead of a
(gdb_byte *, size) couple.
This makes these methods' API probably more C++-idiomatic.
* gmp-utils.h (gdb_mpz::read): Change buf and len parameters
into one single gdb::array_view parameter.
(gdb_mpz::write): Likewise.
(gdb_mpq::read_fixed_point, gdb_mpq::write_fixed_point): Likewise.
* gmp-utils.c (gdb_mpz::read): Change buf and len parameters
into one single gdb::array_view parameter.
Adjust implementation accordingly.
(gdb_mpz::write): Likewise.
(gdb_mpq::read_fixed_point, gdb_mpq::write_fixed_point): Likewise.
* unittests/gmp-utils-selftests.c: Adapt following changes above.
* valarith.c, valops.c, valprint.c, value.c: Likewise.
This patch adds support for binary operations on fixed-point values,
as well as for the negative unary operator.
gdb/ChangeLog:
* eval.c (binop_promote): Add fixed-point type handling.
* valarith.c (fixed_point_binop): New function.
(scalar_binop): Add fixed-point type handling.
(value_neg): Add fixed-point type handling.
* valops.c (value_cast_to_fixed_point): New function.
(value_cast): Add fixed-point type handling.
gdb/testsuite/ChangeLog:
* gdb.dwarf2/dw2-fixed-point.exp: Add arithmetic tests.
The gdb.cp/ambiguous.exp testcase had been disabled for many years,
but recently it was re-enabled. However, it is failing everywhere.
That is because it is testing an old feature that is gone from GDB.
The testcase is expecting to see an ambiguous field warning, like:
# X is derived from A1 and A2; both A1 and A2 have a member 'x'
send_gdb "print x.x\n"
gdb_expect {
-re "warning: x ambiguous; using X::A2::x. Use a cast to disambiguate.\r\n\\$\[0-9\]* = \[-\]*\[0-9\]*\r\n$gdb_prompt $" {
pass "print x.x"
}
-re "warning: x ambiguous; using X::A1::x. Use a cast to disambiguate.\r\n\\$\[0-9\]* = \[-\]*\[0-9\]*\r\n$gdb_prompt $" {
pass "print x.x"
}
-re ".*$gdb_prompt $" { fail "print x.x" }
timeout { fail "(timeout) print x.x" }
}
However, GDB just accesses one of the candidates without warning or
error:
print x.x
$1 = 1431655296
(gdb) FAIL: gdb.cp/ambiguous.exp: print x.x
(The weird number is because the testcase does not initialize the
variables.)
The testcase come in originally with the big HP merge:
+Sun Jan 10 23:44:11 1999 David Taylor <taylor@texas.cygnus.com>
+
+
+ The following files are part of the HP merge; some had longer
+ names at HP, but have been renamed to be no more than 14
+ characters in length.
Looking at the tree back then, we find that warning:
/* Helper function used by value_struct_elt to recurse through baseclasses.
Look for a field NAME in ARG1. Adjust the address of ARG1 by OFFSET bytes,
and search in it assuming it has (class) type TYPE.
If found, return value, else return NULL.
If LOOKING_FOR_BASECLASS, then instead of looking for struct fields,
look for a baseclass named NAME. */
static value_ptr
search_struct_field (name, arg1, offset, type, looking_for_baseclass)
char *name;
register value_ptr arg1;
int offset;
register struct type *type;
int looking_for_baseclass;
{
int found = 0;
char found_class[1024];
value_ptr v;
struct type *vbase = NULL;
found_class[0] = '\000';
v = search_struct_field_aux (name, arg1, offset, type, looking_for_baseclass, &found, found_class, &vbase);
if (found > 1)
warning ("%s ambiguous; using %s::%s. Use a cast to disambiguate.",
name, found_class, name);
return v;
}
However, in current GDB, search_struct_field does not handle the
ambiguous field case, nor is that warning found anywhere. Somehow it
got lost over the years. That seems like a regression, because the
compiler (as per language rules) rejects the ambiguous accesses as
well. E.g.:
gdb.cp/ambiguous.cc:98:5: error: request for member 'x' is ambiguous
98 | x.x = 1;
| ^
gdb.cp/ambiguous.cc:10:7: note: candidates are: 'int A2::x'
10 | int x;
| ^
gdb.cp/ambiguous.cc:4:7: note: 'int A1::x'
4 | int x;
| ^
This patch restores the feature, though implemented differently and
with better user experience, IMHO. An ambiguous access is now an
error instead of a warning, and also GDB shows you all the candidates,
like:
(gdb) print x.x
Request for member 'x' is ambiguous in type 'X'. Candidates are:
'int A1::x' (X -> A1)
'int A2::x' (X -> A2)
(gdb) print j.x
Request for member 'x' is ambiguous in type 'J'. Candidates are:
'int A1::x' (J -> K -> A1)
'int A1::x' (J -> L -> A1)
Users can then fix their commands by casting or by specifying the
baseclass explicitly, like:
(gdb) p x.A1::x
$1 = 1
(gdb) p x.A2::x
$2 = 2
(gdb) p ((A1) x).x
$3 = 1
(gdb) p ((A2) x).x
$4 = 2
(gdb) p j.K::x
$12 = 1
(gdb) p j.L::x
$13 = 2
(gdb) p j.A1::x
base class 'A1' is ambiguous in type 'J'
The last error I've not touched; could be improved to also list the
baseclass candidates.
The showing the class "path" for each candidate was inspired by GCC's
output when you try an ambiguous cast:
gdb.cp/ambiguous.cc:161:8: error: ambiguous conversion from derived class 'const JVA1' to base class 'const A1':
class JVA1 -> class KV -> class A1
class JVA1 -> class A1
(A1) jva1;
^~~~
I did not include the "class" word as it seemed unnecessarily
repetitive, but I can include it if people prefer it:
(gdb) print j.x
Request for member 'x' is ambiguous in type 'J'. Candidates are:
'int A1::x' (class J -> class K -> class A1)
'int A1::x' (class J -> class L -> class A1)
The testcase is adjusted accordingly. I also took the chance to
modernize it at the same time.
Also, as mentioned above, the testcase doesn't currently initialize
the tested variables. This patch inializes them all, giving each
field a distinct value, so that we can be sure that GDB is accessing
the right fields / offsets. The testcase is extended accordingly.
Unfortunately, this exposes a bug, not addressed in this patch. The
bug is around a class that inherits from A1 directly and also inherits
from two other distinct base classes that inherit virtually from A1 in
turn:
print jva1.KV::x
$51 = 1431665544
(gdb) FAIL: gdb.cp/ambiguous.exp: all fields: print jva1.KV::x
print jva1.KV::y
$52 = 21845
(gdb) FAIL: gdb.cp/ambiguous.exp: all fields: print jva1.KV::y
(gdb) print /x (KV)jva1
$4 = {<A1> = <invalid address>, _vptr.KV = 0x555555557b88 <vtable for JVA1+24>, i = 0x457}
(gdb) print /x (A1)(KV)jva1
Cannot access memory at address 0x0
Since that's an orthogonal issue, I filed PR c++/26550 and kfailed the
tests that fail because of it.
gdb/ChangeLog:
PR exp/26602
* valops.c (struct struct_field_searcher): New.
(update_search_result): Rename to ...
(struct_field_searcher::update_result): ... this. Simplify
prototype. Record all found fields.
(do_search_struct_field): Rename to ...
(struct_field_searcher::search): ... this. Simplify prototype.
Maintain stack of visited baseclass path. Call update_result for
fields too. Keep searching fields in baseclasses instead of
stopping at the first found field.
(search_struct_field): Use struct_field_searcher. When looking
for fields, report ambiguous access attempts.
gdb/testsuite/ChangeLog:
PR exp/26602
PR c++/26550
* gdb.cp/ambiguous.cc (marker1): Delete.
(main): Initialize all the fields of the locals. Replace marker1
call with a "set breakpoint here" marker.
* gdb.cp/ambiguous.exp: Modernize. Use gdb_continue_to_breakpoint
instead of running to marker1. Add tests printing all the
variables and all the fields of the variables.
(test_ambiguous): New proc, expecting the new GDB output when a
field access is ambiguous. Change all "warning: X ambiguous"
tests to use it.
Convert language_data::string_lower_bound member variable to a virtual
method language_defn::string_lower_bound.
Over all of the languages we currently support there are currently
only two values for the lower bound, 0 or 1. I noticed that in all
cases, if a language has C style arrays then the lower bound is 0,
otherwise the lower bound is 1. So the default for the virtual method
in language.h makes use of this, which means languages don't have to
worry about providing a string_lower_bound method at all.
Except for Modula2. This language is defined to not have C style
arrays, but has a string_lower_bound index of 0, this behaviour is
maintained after this commit by having Modula2 be the only language
that overrides the string_lower_bound method.
There should be no user visible changes after this commit.
gdb/ChangeLog:
* ada-lang.c (ada_language_data): Remove string_lower_bound
initializer.
* c-lang.c (c_language_data): Likewise.
(cplus_language_data): Likewise.
(asm_language_data): Likewise.
(minimal_language_data): Likewise.
* d-lang.c (d_language_data): Likewise.
* f-lang.c (f_language_data): Likewise.
* go-lang.c (go_language_data): Likewise.
* language.c (unknown_language_data): Likewise.
(auto_language_data): Likewise.
* language.h (language_data): Remove string_lower_bound field.
(language_defn::string_lower_bound): New member function.
* m2-lang.c (m2_language_data): Remove string_lower_bound
initializer.
(m2_language::string_lower_bound): New member function.
* objc-lang.c (objc_language_data): Remove string_lower_bound
initializer.
* opencl-lang.c (opencl_language_data): Likewise.
* p-lang.c (pascal_language_data): Likewise.
* rust-lang.c (rust_language_data): Likewise.
* valops.c (value_cstring): Update call to string_lower_bound.
(value_string): Likewise.
* value.c (allocate_repeated_value): Likewise.
After dereferencing a pointer (in value_ind) or following a
reference (in coerce_ref) we call readjust_indirect_value_type to
"fixup" the type of the resulting value object.
This fixup handles cases relating to the type of the resulting object
being different (a sub-class) of the original pointers target type.
If we encounter a pointer to a dynamic type then after dereferencing a
pointer (in value_ind) the type of the object created will have had
its dynamic type resolved. However, in readjust_indirect_value_type,
we use the target type of the original pointer to "fixup" the type of
the resulting value. In this case, the target type will be a dynamic
type, so the resulting value object, once again has a dynamic type.
This then triggers an assertion later within GDB.
The solution I propose here is that we call resolve_dynamic_type on
the pointer's target type (within readjust_indirect_value_type) so
that the resulting value is not converted back to a dynamic type.
The test case is based on the original test in the bug report.
gdb/ChangeLog:
PR fortran/23051
PR fortran/26139
* valops.c (value_ind): Pass address to
readjust_indirect_value_type.
* value.c (readjust_indirect_value_type): Make parameter
non-const, and add extra address parameter. Resolve original type
before using it.
* value.h (readjust_indirect_value_type): Update function
signature and comment.
gdb/testsuite/ChangeLog:
PR fortran/23051
PR fortran/26139
* gdb.fortran/class-allocatable-array.exp: New file.
* gdb.fortran/class-allocatable-array.f90: New file.
* gdb.fortran/pointer-to-pointer.exp: New file.
* gdb.fortran/pointer-to-pointer.f90: New file.
Getting the bounds of an array (or string) type is a common operation,
and is currently done through its index type:
my_array_type->index_type ()->bounds ()
I think it would make sense to let the `type::bounds` methods work for
arrays and strings, as a shorthand for this. It's natural that when
asking for the bounds of an array, we get the bounds of the range type
used as its index type. In a way, it's equivalent as the now-removed
TYPE_ARRAY_{LOWER,UPPER}_BOUND_IS_UNDEFINED and
TYPE_ARRAY_{LOWER,UPPER}_BOUND_VALUE, except it returns the
`range_bounds` object. The caller is then responsible for getting the
property it needs in it.
I updated all the spots I could find that could take advantage of this.
Note that this also makes `type::bit_stride` work on array types, since
`type::bit_stride` uses `type::bounds`. `my_array_type->bit_stride ()`
now returns the bit stride of the array's index type. So some spots
are also changed to take advantage of this.
gdb/ChangeLog:
* gdbtypes.h (struct type) <bounds>: Handle array and string
types.
* ada-lang.c (assign_aggregate): Use type::bounds on
array/string type.
* c-typeprint.c (c_type_print_varspec_suffix): Likewise.
* c-varobj.c (c_number_of_children): Likewise.
(c_describe_child): Likewise.
* eval.c (evaluate_subexp_for_sizeof): Likewise.
* f-typeprint.c (f_type_print_varspec_suffix): Likewise.
(f_type_print_base): Likewise.
* f-valprint.c (f77_array_offset_tbl): Likewise.
(f77_get_upperbound): Likewise.
(f77_print_array_1): Likewise.
* guile/scm-type.c (gdbscm_type_range): Likewise.
* m2-typeprint.c (m2_array): Likewise.
(m2_is_long_set_of_type): Likewise.
* m2-valprint.c (get_long_set_bounds): Likewise.
* p-typeprint.c (pascal_type_print_varspec_prefix): Likewise.
* python/py-type.c (typy_range): Likewise.
* rust-lang.c (rust_internal_print_type): Likewise.
* type-stack.c (type_stack::follow_types): Likewise.
* valarith.c (value_subscripted_rvalue): Likewise.
* valops.c (value_cast): Likewise.
Change-Id: I5c0c08930bffe42fd69cb4bfcece28944dd88d1f
Remove the macros, use the various equivalent getters instead.
gdb/ChangeLog:
* gdbtypes.h (TYPE_ARRAY_UPPER_BOUND_IS_UNDEFINED,
TYPE_ARRAY_LOWER_BOUND_IS_UNDEFINED): Remove. Update all
callers to use the equivalent accessor methods instead.
Change-Id: Ifb4c36f440b82533bde5d15a5cbb2fc91f467292
Remove the `TYPE_FIELD_TYPE` macro, changing all the call sites to use
`type::field` and `field::type` directly.
gdb/ChangeLog:
* gdbtypes.h (TYPE_FIELD_TYPE): Remove. Change all call sites
to use type::field and field::type instead.
Change-Id: Ifda6226a25c811cfd334a756a9fbc5c0afdddff3
Add the `type` and `set_type` methods on `struct field`, in order to
remoremove the `FIELD_TYPE` macro. In this patch, the `FIELD_TYPE`
macro is changed to use `field::type`, so all the call sites that are
useused to set the field's type are changed to use `field::set_type`.
The next patch will remove `FIELD_TYPE` completely.
Note that because of the name clash between the existing field named
`type` and the new method, I renamed the field `m_type`. It is not
private per-se, because we can't make `struct field` a non-POD yet, but
it should be considered private anyway (not accessed outside `struct
field`).
gdb/ChangeLog:
* gdbtypes.h (struct field) <type, set_type>: New methods.
Rename `type` field to...
<m_type>: ... this. Change references throughout to use type or
set_type methods.
(FIELD_TYPE): Use field::type. Change call sites that modify
the field's type to use field::set_type instead.
Change-Id: Ie21f866e3b7f8a51ea49b722d07d272a724459a0
Remove `TYPE_INDEX_TYPE` macro, changing all the call sites to use
`type::index_type` directly.
gdb/ChangeLog:
* gdbtypes.h (TYPE_INDEX_TYPE): Remove. Change all call sites
to use type::index_type instead.
Change-Id: I56715df0bdec89463cda6bd341dac0e01b2faf84
Replace all uses of it by type::field.
Note that since type::field returns a reference to the field, some spots
are used to assign the whole field structure. See ctfread.c, function
attach_fields_to_type, for example. This is the same as was happening
with the macro, so I don't think it's a problem, but if anybody sees a
really nicer way to do this, now could be a good time to implement it.
gdb/ChangeLog:
* gdbtypes.h (TYPE_FIELD): Remove. Replace all uses with
type::field.
Remove `TYPE_NFIELDS`, changing all the call sites to use
`type::num_fields` directly. This is quite a big diff, but this was
mostly done using sed and coccinelle. A few call sites were done by
hand.
gdb/ChangeLog:
* gdbtypes.h (TYPE_NFIELDS): Remove. Change all cal sites to use
type::num_fields instead.
Change-Id: Ib73be4c36f9e770e0f729bac3b5257d7cb2f9591
Remove `TYPE_NAME`, changing all the call sites to use `type::name`
directly. This is quite a big diff, but this was mostly done using sed
and coccinelle. A few call sites were done by hand.
gdb/ChangeLog:
* gdbtypes.h (TYPE_NAME): Remove. Change all cal sites to use
type::name instead.
Remove TYPE_CODE, changing all the call sites to use type::code
directly. This is quite a big diff, but this was mostly done using sed
and coccinelle. A few call sites were done by hand.
gdb/ChangeLog:
* gdbtypes.h (TYPE_CODE): Remove. Change all call sites to use
type::code instead.
Add the code and set_code methods on code, in order to remove the
TYPE_CODE macro. In this patch, the TYPE_CODE macro is changed to use
type::code, so all the call sites that are used to set the type code are
changed to use type::set_code. The next patch will remove TYPE_CODE
completely.
gdb/ChangeLog:
* gdbtypes.h (struct type) <code, set_code>: New methods.
(TYPE_CODE): Use type::code. Change all call sites used to set
the code to use type::set_code instead.
This rewrites the existing variant part code to follow the new model
implemented in the previous patch. The old variant part code is
removed.
This only affects Rust for the moment. I tested this using various
version of the Rust compiler, including one that emits old-style enum
debuginfo, exercising the quirks code.
gdb/ChangeLog
2020-04-24 Tom Tromey <tromey@adacore.com>
* dwarf2/read.c (struct variant_field): Rewrite.
(struct variant_part_builder): New.
(struct nextfield): Remove "variant" field. Add "offset".
(struct field_info): Add "current_variant_part" and
"variant_parts".
(alloc_discriminant_info): Remove.
(alloc_rust_variant): New function.
(quirk_rust_enum): Update.
(dwarf2_add_field): Set "offset" member. Don't handle
DW_TAG_variant_part.
(offset_map_type): New typedef.
(convert_variant_range, create_one_variant)
(create_one_variant_part, create_variant_parts)
(add_variant_property): New functions.
(dwarf2_attach_fields_to_type): Call add_variant_property.
(read_structure_type): Don't handle DW_TAG_variant_part.
(handle_variant_part, handle_variant): New functions.
(handle_struct_member_die): Use them.
(process_structure_scope): Don't handle variant parts.
* gdbtypes.h (TYPE_FLAG_DISCRIMINATED_UNION): Remove.
(struct discriminant_info): Remove.
(enum dynamic_prop_node_kind) <DYN_PROP_DISCRIMINATED>: Remove.
(struct main_type) <flag_discriminated_union>: Remove.
* rust-lang.c (rust_enum_p, rust_empty_enum_p): Rewrite.
(rust_enum_variant): Return int. Remove "contents". Rewrite.
(rust_print_enum, rust_print_struct_def, rust_evaluate_subexp):
Update.
* valops.c (value_union_variant): Remove.
* value.h (value_union_variant): Don't declare.
Christian pointed out that the value_literal_complex was still a bit
weird; this patch rewrites it and moves it to value.h.
gdb/ChangeLog
2020-04-01 Tom Tromey <tom@tromey.com>
* value.h (value_literal_complex): Add comment.
* valops.c (value_literal_complex): Refer to value.h.
This introduces two new functions that make it simpler to access the
components of a complex number.
gdb/ChangeLog
2020-04-01 Tom Tromey <tom@tromey.com>
* valprint.c (generic_value_print_complex): Use accessors.
* value.h (value_real_part, value_imaginary_part): Declare.
* valops.c (value_real_part, value_imaginary_part): New
functions.
* value.c (creal_internal_fn, cimag_internal_fn): Use accessors.
While working on complex number support, I found a couple of
apparently obsolete coments. This removes them.
2020-03-07 Tom Tromey <tom@tromey.com>
* valops.c (value_literal_complex): Remove obsolete comment.
* gdbtypes.h (enum type_code) <TYPE_CODE_FLT>: Remove obsolete
comment.
Function overload resolution prints debug output if turned on via the
'set debug overload' command. The output includes the badness vector
(BV). For each function, this vector contains a badness value of the
length of parameters as its first element. So, BV[0] does not
correspond to a parameter. The badness values of parameters start
with BV[1].
A badness value is a pair; it contains a rank and a subrank. Printing
both fields provides useful information.
Improve printing the badness vector along these lines.
gdb/ChangeLog:
2019-11-29 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* valops.c (find_oload_champ): Improve debug output.
Change-Id: I771017e7afbbaf4809e2238a9b23274f55c61f55
A segfault occurs if overload resolution debug mode is turned on via
the 'set debug overload' command. E.g.:
~~~
$ gdb ./a.out
...
(gdb) start
...
(gdb) set debug overload 1
(gdb) print foo(5)
-- Arg is int [8], parm is double [9]
Overloaded function instance (null) # of parms 1
Segmentation fault
$
~~~
The problem is, GDB tries to print the badness vector after it has
been std::move'd. Fix the problem by printing the vector before it is
moved.
gdb/ChangeLog:
2019-11-29 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* valops.c (find_oload_champ): Print part of debug messages
before the badness vector is std::move'd.
Change-Id: Ia623f9637e82ec332bfeac23eb6b0f2ffdcdde27
- Rationale:
It is possible for compilers to indicate the desired byte order
interpretation of scalar variables using the DWARF attribute:
DW_AT_endianity
A type flagged with this variable would typically use one of:
DW_END_big
DW_END_little
which instructs the debugger what the desired byte order interpretation
of the variable should be.
The GCC compiler (as of V6) has a mechanism for setting the desired byte
ordering of the fields within a structure or union. For, example, on a
little endian target, a structure declared as:
struct big {
int v;
short a[4];
} __attribute__( ( scalar_storage_order( "big-endian" ) ) );
could be used to ensure all the structure members have a big-endian
interpretation (the compiler would automatically insert byte swap
instructions before and after respective store and load instructions).
- To reproduce
GCC V8 is required to correctly emit DW_AT_endianity DWARF attributes
in all situations when the scalar_storage_order attribute is used.
A fix for (dwarf endianity instrumentation) for GCC V6-V7 can be found
in the URL field of the following PR:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82509
- Test-case:
A new test case (testsuite/gdb.base/endianity.*) is included with this
patch.
Manual testing for mixed endianity code has also been done with GCC V8.
See:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82509#c4
- Observed vs. expected:
Without this change, using scalar_storage_order that doesn't match the
target, such as
struct otherendian
{
int v;
} __attribute__( ( scalar_storage_order( "big-endian" ) ) );
would behave like the following on a little endian target:
Breakpoint 1 at 0x401135: file endianity.c, line 41.
(gdb) run
Starting program: /home/pjoot/freeware/t/a.out
Missing separate debuginfos, use: debuginfo-install glibc-2.17-292.el7.x86_64
Breakpoint 1, main () at endianity.c:41
41 struct otherendian o = {3};
(gdb) n
43 do_nothing (&o); /* START */
(gdb) p o
$1 = {v = 50331648}
(gdb) p /x
$2 = {v = 0x3000000}
whereas with this gdb enhancement we can access the variable with the user
specified endianity:
Breakpoint 1, main () at endianity.c:41
41 struct otherendian o = {3};
(gdb) p o
$1 = {v = 0}
(gdb) n
43 do_nothing (&o); /* START */
(gdb) p o
$2 = {v = 3}
(gdb) p o.v = 4
$3 = 4
(gdb) p o.v
$4 = 4
(gdb) x/4xb &o.v
0x7fffffffd90c: 0x00 0x00 0x00 0x04
(observe that the 4 byte int variable has a big endian representation in the
hex dump.)
gdb/ChangeLog
2019-11-21 Peeter Joot <peeter.joot@lzlabs.com>
Byte reverse display of variables with DW_END_big, DW_END_little
(DW_AT_endianity) dwarf attributes if different than the native
byte order.
* ada-lang.c (ada_value_binop):
Use type_byte_order instead of gdbarch_byte_order.
* ada-valprint.c (printstr):
(ada_val_print_string):
* ada-lang.c (value_pointer):
(ada_value_binop):
Use type_byte_order instead of gdbarch_byte_order.
* c-lang.c (c_get_string):
Use type_byte_order instead of gdbarch_byte_order.
* c-valprint.c (c_val_print_array):
Use type_byte_order instead of gdbarch_byte_order.
* cp-valprint.c (cp_print_class_member):
Use type_byte_order instead of gdbarch_byte_order.
* dwarf2loc.c (rw_pieced_value):
Use type_byte_order instead of gdbarch_byte_order.
* dwarf2read.c (read_base_type): Handle DW_END_big,
DW_END_little
* f-lang.c (f_get_encoding):
Use type_byte_order instead of gdbarch_byte_order.
* findvar.c (default_read_var_value):
Use type_byte_order instead of gdbarch_byte_order.
* gdbtypes.c (check_types_equal):
Require matching TYPE_ENDIANITY_NOT_DEFAULT if set.
(recursive_dump_type): Print TYPE_ENDIANITY_BIG,
and TYPE_ENDIANITY_LITTLE if set.
(type_byte_order): new function.
* gdbtypes.h (TYPE_ENDIANITY_NOT_DEFAULT): New macro.
(struct main_type) <flag_endianity_not_default>:
New field.
(type_byte_order): New function.
* infcmd.c (default_print_one_register_info):
Use type_byte_order instead of gdbarch_byte_order.
* p-lang.c (pascal_printstr):
Use type_byte_order instead of gdbarch_byte_order.
* p-valprint.c (pascal_val_print):
Use type_byte_order instead of gdbarch_byte_order.
* printcmd.c (print_scalar_formatted):
Use type_byte_order instead of gdbarch_byte_order.
* solib-darwin.c (darwin_current_sos):
Use type_byte_order instead of gdbarch_byte_order.
* solib-svr4.c (solib_svr4_r_ldsomap):
Use type_byte_order instead of gdbarch_byte_order.
* stap-probe.c (stap_modify_semaphore):
Use type_byte_order instead of gdbarch_byte_order.
* target-float.c (target_float_same_format_p):
Use type_byte_order instead of gdbarch_byte_order.
* valarith.c (scalar_binop):
(value_bit_index):
Use type_byte_order instead of gdbarch_byte_order.
* valops.c (value_cast):
Use type_byte_order instead of gdbarch_byte_order.
* valprint.c (generic_emit_char):
(generic_printstr):
(val_print_string):
Use type_byte_order instead of gdbarch_byte_order.
* value.c (unpack_long):
(unpack_bits_as_long):
(unpack_value_bitfield):
(modify_field):
(pack_long):
(pack_unsigned_long):
Use type_byte_order instead of gdbarch_byte_order.
* findvar.c (unsigned_pointer_to_address):
(signed_pointer_to_address):
(unsigned_address_to_pointer):
(address_to_signed_pointer):
(default_read_var_value):
(default_value_from_register):
Use type_byte_order instead of gdbarch_byte_order.
* gnu-v3-abi.c (gnuv3_make_method_ptr):
Use type_byte_order instead of gdbarch_byte_order.
* riscv-tdep.c (riscv_print_one_register_info):
Use type_byte_order instead of gdbarch_byte_order.
gdb/testsuite/ChangeLog
2019-11-21 Peeter Joot <peeter.joot@lzlabs.com>
* gdb.base/endianity.c: New test.
* gdb.base/endianity.exp: New file.
Change-Id: I4bd98c1b4508c2d7c5a5dbb15d7b7b1cb4e667e2
... and move comment to header file.
gdb/ChangeLog:
* valops.c (value_must_coerce_to_target): Change return type to
bool.
* value.h (value_must_coerce_to_target): Likewise.
In Ada, the term for a cast is "type conversion". AdaCore has been
carrying a local patch to specialize the error message in value_cast,
but it seemed fine to me for this to be part of gdb. This also
removes a dead "return" statement.
gdb/ChangeLog
2019-07-10 Tom Tromey <tromey@adacore.com>
* valops.c (value_cast): Specialize error message for Ada.
Andrew Burgess