This commit is the result of running the gdb/copyright.py script,
which automated the update of the copyright year range for all
source files managed by the GDB project to be updated to include
year 2023.
This changes GDB to use frame_info_ptr instead of frame_info *
The substitution was done with multiple sequential `sed` commands:
sed 's/^struct frame_info;/class frame_info_ptr;/'
sed 's/struct frame_info \*/frame_info_ptr /g' - which left some
issues in a few files, that were manually fixed.
sed 's/\<frame_info \*/frame_info_ptr /g'
sed 's/frame_info_ptr $/frame_info_ptr/g' - used to remove whitespace
problems.
The changed files were then manually checked and some 'sed' changes
undone, some constructors and some gets were added, according to what
made sense, and what Tromey originally did
Co-Authored-By: Bruno Larsen <blarsen@redhat.com>
Approved-by: Tom Tomey <tom@tromey.com>
This commit brings all the changes made by running gdb/copyright.py
as per GDB's Start of New Year Procedure.
For the avoidance of doubt, all changes in this commits were
performed by the script.
There are cases where the result of the expression evaluation is
expected to be in a form of a value and not location description.
One place that has this requirement is dwarf_entry_parameter_to_value
function, but more are expected in the future. Until now, this
requirement was fulfilled by extending the evaluated expression with
a DW_OP_stack_value operation at the end.
New implementation, introduces a new evaluation argument instead.
* dwarf2/expr.c (dwarf_expr_context::fetch_result): Add as_lval
argument.
(dwarf_expr_context::eval_exp): Add as_lval argument.
* dwarf2/expr.h (struct dwarf_expr_context): Add as_lval
argument to fetch_result and eval_exp methods.
* dwarf2/frame.c (execute_stack_op): Add as_lval argument.
* dwarf2/loc.c (dwarf_entry_parameter_to_value): Remove
DWARF expression extension.
(dwarf2_evaluate_loc_desc_full): Add as_lval argument support.
(dwarf2_evaluate_loc_desc): Add as_lval argument support.
(dwarf2_locexpr_baton_eval): Add as_lval argument support.
Idea of this patch is to get a clean and simple public interface for
the dwarf_expr_context class, looking like:
- constructor,
- destructor,
- push_address method and
- evaluate method.
Where constructor should only ever require a target architecture
information. This information is held in per object file
(dwarf2_per_objfile) structure, so it makes sense to keep that
structure as a constructor argument. It also makes sense to get the
address size from that structure, but unfortunately that interface
doesn't exist at the moment, so the dwarf_expr_context class user
needs to provide that information.
The push_address method is used to push a CORE_ADDR as a value on
top of the DWARF stack before the evaluation. This method can be
later changed to push any struct value object on the stack.
The evaluate method is the method that evaluates a DWARF expression
and provides the evaluation result, in a form of a single struct
value object that describes a location. To do this, the method requires
a context of the evaluation, as well as expected result type
information. If the type information is not provided, the DWARF generic
type will be used instead.
To avoid storing the gdbarch information in the evaluator object, that
information is now always acquired from the per_objfile object.
All data members are now private and only visible to the evaluator
class, so a m_ prefix was added to all of their names to reflect that.
To make this distinction clear, they are also accessed through objects
this pointer, wherever that was not the case before.
gdb/ChangeLog:
* dwarf2/expr.c (dwarf_expr_context::dwarf_expr_context): Add
address size argument.
(dwarf_expr_context::read_mem): Change to use property_addr_info
structure.
(dwarf_expr_context::evaluate): New function.
(dwarf_expr_context::execute_stack_op): Change to use
property_addr_info structure.
* dwarf2/expr.h (struct dwarf_expr_context): New evaluate
declaration. Change eval and fetch_result method to private.
(dwarf_expr_context::gdbarch): Remove member.
(dwarf_expr_context::stack): Make private and add m_ prefix.
(dwarf_expr_context::addr_size): Make private and add
m_ prefix.
(dwarf_expr_context::recursion_depth): Make private and add
m_ prefix.
(dwarf_expr_context::max_recursion_depth): Make private and
add m_ prefix.
(dwarf_expr_context::len): Make private and add m_ prefix.
(dwarf_expr_context::data): Make private and add m_ prefix.
(dwarf_expr_context::initialized): Make private and add
m_ prefix.
(dwarf_expr_context::pieces): Make private and add m_ prefix.
(dwarf_expr_context::per_objfile): Make private and add
m_ prefix.
(dwarf_expr_context::frame): Make private and add m_ prefix.
(dwarf_expr_context::per_cu): Make private and add m_ prefix.
(dwarf_expr_context::addr_info): Make private and add
m_ prefix.
* dwarf2/frame.c (execute_stack_op): Change to call evaluate
method.
* dwarf2/loc.c (dwarf2_evaluate_loc_desc_full): Change to call
evaluate method.
(dwarf2_locexpr_baton_eval): Change to call evaluate method.
The patch is addressing the issue of class users writing and reading
the internal data of the dwarf_expr_context class.
At this point, all conditions are met for the DWARF evaluator to return
an evaluation result in a form of a single struct value object.
gdb/ChangeLog:
* dwarf2/expr.c (pieced_value_funcs): Chenge to static
function.
(allocate_piece_closure): Change to static function.
(dwarf_expr_context::fetch_result): New function.
* dwarf2/expr.h (struct piece_closure): Remove declaration.
(struct dwarf_expr_context): fetch_result new declaration.
fetch, fetch_address and fetch_in_stack_memory members move
to private.
(allocate_piece_closure): Remove.
* dwarf2/frame.c (execute_stack_op): Change to use
fetch_result.
* dwarf2/loc.c (dwarf2_evaluate_loc_desc_full): Change to use
fetch_result.
(dwarf2_locexpr_baton_eval): Change to use fetch_result.
* dwarf2/loc.h (invalid_synthetic_pointer): Expose function.
Following 5 patches series is trying to clean up the interface of the
DWARF expression evaluator class (dwarf_expr_context).
After merging all expression evaluators into one class, the next
logical step is to make a clean user interface for that class. To do
that, we first need to address the issue of class users writing and
reading the internal data of the class directly.
Fixing the case of writing is simple, it makes sense for an evaluator
instance to be per architecture basis. Currently, the best separation
seems to be per object file, so having that data (dwarf2_per_objfile)
as a constructor argument makes sense. It also makes sense to get the
address size from that object file, but unfortunately that interface
does not exist at the moment.
Luckily, address size information is already available to the users
through other means. As a result, the address size also needs to be a
class constructor argument, at least until a better interface for
acquiring that information from an object file is implemented.
The rest of the user written data comes down to a context of an
evaluated expression (compilation unit context, frame context and
passed in buffer context) and a source type information that a result
of evaluating expression is representing. So, it makes sense for all of
these to be arguments of an evaluation method.
To address the problem of reading the dwarf_expr_context class
internal data, we first need to understand why it is implemented that
way?
This is actualy a question of which existing class can be used to
represent both values and a location descriptions and why it is not
used currently?
The answer is in a struct value class/structure, but the problem is
that before the evaluators were merged, only one evaluator had an
infrastructure to resolve composite and implicit pointer location
descriptions.
After the merge, we are now able to use the struct value to represent
any result of the expression evaluation. It also makes sense to move
all infrastructure for those location descriptions to the expr.c file
considering that that is the only place using that infrastructure.
What we are left with in the end is a clean public interface of the
dwarf_expr_context class containing:
- constructor,
- destructor,
- push_address method and
- eval_exp method.
The idea with this particular patch is to move piece_closure structure
and the interface that handles it (lval_funcs) to expr.c file.
While implicit pointer location descriptions are still not useful in
the CFI context (of the AMD's DWARF standard extensions), the composite
location descriptions are certainly necessary to describe a results of
specific compiler optimizations.
Considering that a piece_closure structure is used to represent both,
there was no benefit in splitting them.
gdb/ChangeLog:
* dwarf2/expr.c (struct piece_closure): Add from loc.c.
(allocate_piece_closure): Add from loc.c.
(bits_to_bytes): Add from loc.c.
(rw_pieced_value): Add from loc.c.
(read_pieced_value): Add from loc.c.
(write_pieced_value): Add from loc.c.
(check_pieced_synthetic_pointer): Add from loc.c.
(indirect_pieced_value): Add from loc.c.
(coerce_pieced_ref): Add from loc.c.
(copy_pieced_value_closure): Add from loc.c.
(free_pieced_value_closure): Add from loc.c.
(sect_variable_value): Add from loc.c.
* dwarf2/loc.c (sect_variable_value): Move to expr.c.
(struct piece_closure): Move to expr.c.
(allocate_piece_closure): Move to expr.c.
(bits_to_bytes): Move to expr.c.
(rw_pieced_value): Move to expr.c.
(read_pieced_value): Move to expr.c.
(write_pieced_value): Move to expr.c.
(check_pieced_synthetic_pointer): Move to expr.c.
(indirect_pieced_value): Move to expr.c.
(coerce_pieced_ref): Move to expr.c.
(copy_pieced_value_closure): Move to expr.c.
(free_pieced_value_closure): Move to expr.c.
The evaluate_for_locexpr_baton is the last derived class from the
dwarf_expr_context class. It's purpose is to support the passed in
buffer functionality.
Although, it is not really necessary to merge this class with it's
base class, doing that simplifies new expression evaluator design.
Considering that this functionality is going around the DWARF standard,
it is also reasonable to expect that with a new evaluator design and
extending the push object address functionality to accept any location
description, there will be no need to support passed in buffers.
Alternatively, it would also makes sense to abstract the interaction
between the evaluator and a given resource in the near future. The
passed in buffer would then be a specialization of that abstraction.
gdb/ChangeLog:
* dwarf2/expr.c (dwarf_expr_context::read_mem): Merge with
evaluate_for_locexpr_baton implementation.
* dwarf2/loc.c (class evaluate_for_locexpr_baton): Remove
class.
(evaluate_for_locexpr_baton::read_mem): Move to
dwarf_expr_context.
(dwarf2_locexpr_baton_eval): Instantiate dwarf_expr_context
instead of evaluate_for_locexpr_baton class.
The get_reg_value method is a small function that is only called once,
so it can be inlined to simplify the dwarf_expr_context class.
gdb/ChangeLog:
* dwarf2/expr.c (dwarf_expr_context::get_reg_value): Remove
method.
(dwarf_expr_context::execute_stack_op): Inline get_reg_value
method.
* dwarf2/expr.h (dwarf_expr_context::get_reg_value): Remove
method.
Following the idea of merging the evaluators, the
push_dwarf_reg_entry_value method can be moved from
dwarf_expr_executor and dwarf_evaluate_loc_desc classes
to their base class dwarf_expr_context.
gdb/ChangeLog:
* dwarf2/expr.c
(dwarf_expr_context::push_dwarf_reg_entry_value): Move from
dwarf_evaluate_loc_desc.
* dwarf2/frame.c
(dwarf_expr_executor::push_dwarf_reg_entry_value): Remove
method.
* dwarf2/loc.c (dwarf_expr_reg_to_entry_parameter): Expose
function.
(dwarf_evaluate_loc_desc::push_dwarf_reg_entry_value): Move to
dwarf_expr_context.
* dwarf2/loc.h (dwarf_expr_reg_to_entry_parameter): Expose
function.
Following the idea of merging the evaluators, the read_mem method can
be moved from dwarf_expr_executor and dwarf_evaluate_loc_desc classes
to their base class dwarf_expr_context.
gdb/ChangeLog:
* dwarf2/expr.c (dwarf_expr_context::read_mem): Move from
dwarf_evaluate_loc_desc.
* dwarf2/frame.c (dwarf_expr_executor::read_mem): Remove
method.
* dwarf2/loc.c (dwarf_evaluate_loc_desc::read_mem): Move to
dwarf_expr_context.
Following the idea of merging the evaluators, the get_object_address
and can be moved from dwarf_expr_executor and dwarf_evaluate_loc_desc
classes to their base class dwarf_expr_context.
gdb/ChangeLog:
* dwarf2/expr.c (dwarf_expr_context::get_object_address): Move
from dwarf_evaluate_loc_desc.
(class dwarf_expr_context): Add object address member to
dwarf_expr_context.
* dwarf2/expr.h (dwarf_expr_context::get_frame_pc): Remove
method.
* dwarf2/frame.c (dwarf_expr_executor::get_object_address):
Remove method.
* dwarf2/loc.c (dwarf_evaluate_loc_desc::get_object_address):
move to dwarf_expr_context.
(class dwarf_evaluate_loc_desc): Move object address member to
dwarf_expr_context.
Following the idea of merging the evaluators, the dwarf_call and
get_frame_pc method can be moved from dwarf_expr_executor and
dwarf_evaluate_loc_desc classes to their base class dwarf_expr_context.
Once this is done, the get_frame_pc can be replace with lambda
function.
gdb/ChangeLog:
* dwarf2/expr.c (dwarf_expr_context::dwarf_call): Move from
dwarf_evaluate_loc_desc.
(dwarf_expr_context::get_frame_pc): Replace with lambda.
* dwarf2/expr.h (dwarf_expr_context::get_frame_pc): Remove
method.
* dwarf2/frame.c (dwarf_expr_executor::dwarf_call): Remove
method.
(dwarf_expr_executor::get_frame_pc): Remove method.
* dwarf2/loc.c (dwarf_evaluate_loc_desc::get_frame_pc): Remove
method.
(dwarf_evaluate_loc_desc::dwarf_call): Move to
dwarf_expr_context.
(per_cu_dwarf_call): Inline function.
This patch moves the compilation unit context information and support
from dwarf_expr_executor and dwarf_evaluate_loc_desc to
dwarf_expr_context evaluator. The idea is to report an error when a
given operation requires a compilation unit information to be resolved,
which is not available.
With this change, it also makes sense to always acquire ref_addr_size
information from the compilation unit context, considering that all
DWARF operations that refer to that information require a compilation
unit context to be present during their evaluation.
gdb/ChangeLog:
* dwarf2/expr.c (ensure_have_per_cu): New function.
(dwarf_expr_context::dwarf_expr_context): Add compilation unit
context information.
(dwarf_expr_context::get_base_type): Move from
dwarf_evaluate_loc_desc.
(dwarf_expr_context::get_addr_index): Remove method.
(dwarf_expr_context::dwarf_variable_value): Remove method.
(dwarf_expr_context::execute_stack_op): Call compilation unit
context info check. Inline get_addr_index and
dwarf_variable_value methods.
* dwarf2/expr.h (struct dwarf_expr_context): Add compilation
context info.
(dwarf_expr_context::get_addr_index): Remove method.
(dwarf_expr_context::dwarf_variable_value): Remove method.
(dwarf_expr_context::ref_addr_size): Remove member.
* dwarf2/frame.c (dwarf_expr_executor::get_addr_index): Remove
method.
(dwarf_expr_executor::dwarf_variable_value): Remove method.
* dwarf2/loc.c (sect_variable_value): Expose function.
(dwarf_evaluate_loc_desc::get_addr_index): Remove method.
(dwarf_evaluate_loc_desc::dwarf_variable_value): Remove method.
(class dwarf_evaluate_loc_desc): Move compilation unit context
information to dwarf_expr_context class.
* dwarf2/loc.h (sect_variable_value): Expose function.
Following the idea of merging the evaluators, the get_frame_cfa method
can be moved from dwarf_expr_executor and dwarf_evaluate_loc_desc
classes to their base class dwarf_expr_context. Once this is done,
it becomes apparent that the method is only called once and it can be
inlined.
It is also necessary to check if the frame context information was
provided before the DW_OP_call_frame_cfa operation is executed.
gdb/ChangeLog:
* dwarf2/expr.c (dwarf_expr_context::get_frame_cfa): Remove
method.
(dwarf_expr_context::execute_stack_op): Call frame context info
check for DW_OP_call_frame_cfa. Remove use of get_frame_cfa.
* dwarf2/expr.h (dwarf_expr_context::get_frame_cfa): Remove
method.
* dwarf2/frame.c (dwarf_expr_context::get_frame_cfa): Remove
method.
* dwarf2/loc.c (dwarf_expr_context::get_frame_cfa): Remove
method.
Following 15 patches in this patch series is cleaning up the design of
the DWARF expression evaluator (dwarf_expr_context) to make future
extensions of that evaluator easier and cleaner to implement.
There are three subclasses of the dwarf_expr_context class
(dwarf_expr_executor, dwarf_evaluate_loc_desc and
evaluate_for_locexpr_baton). Here is a short description of each class:
- dwarf_expr_executor is evaluating a DWARF expression in a context
of a Call Frame Information. The overridden methods of this subclass
report an error if a specific DWARF operation, represented by that
method, is not allowed in a CFI context. The source code of this
subclass lacks the support for composite as well as implicit pointer
location description.
- dwarf_evaluate_loc_desc can evaluate any expression with no
restrictions. All of the methods that this subclass overrides are
actually doing what they are intended to do. This subclass contains
a full support for all location description types.
- evaluate_for_locexpr_baton subclass is a specialization of the
dwarf_evaluate_loc_desc subclass and it's function is to add
support for passed in buffers. This seems to be a way to go around
the fact that DWARF standard lacks a bit offset support for memory
location descriptions as well as using any location description for
the push object address functionality.
It all comes down to this question: what is a function of a DWARF
expression evaluator?
Is it to evaluate the expression in a given context or to check the
correctness of that expression in that context?
Currently, the only reason why there is a dwarf_expr_executor subclass
is to report an invalid DWARF expression in a context of a CFI, but is
that what the evaluator is supposed to do considering that the evaluator
is not tied to a given DWARF version?
There are more and more vendor and GNU extensions that are not part of
the DWARF standard, so is it that impossible to expect that some of the
extensions could actually lift the previously imposed restrictions of
the CFI context? Not to mention that every new DWARF version is lifting
some restrictions anyway.
The thing that makes more sense for an evaluator to do, is to take the
context of an evaluation and checks the requirements of every operation
evaluated against that context. With this approach, the evaluator would
report an error only if parts of the context, necessary for the
evaluation, are missing.
If this approach is taken, then the unification of the
dwarf_evaluate_loc_desc, dwarf_expr_executor and dwarf_expr_context
is the next logical step. This makes a design of the DWARF expression
evaluator cleaner and allows more flexibility when supporting future
vendor and GNU extensions.
Additional benefit here is that now all evaluators have access to all
location description types, which means that a vendor extended CFI
rules could support composite location description as well. This also
means that a new evaluator interface can be changed to return a single
struct value (that describes the result of the evaluation) instead of
a caller poking around the dwarf_expr_context internal data for answers
(like it is done currently).
This patch starts the merging process by moving the frame context
information and support from dwarf_expr_executor and
dwarf_evaluate_loc_desc to dwarf_expr_context evaluator. The idea
is to report an error when a given operation requires a frame
information to be resolved, if that information is not present.
gdb/ChangeLog:
* dwarf2/expr.c (ensure_have_frame): New function.
(read_addr_from_reg): Add from frame.c.
(dwarf_expr_context::dwarf_expr_context): Add frame info to
dwarf_expr_context.
(dwarf_expr_context::read_addr_from_reg): Remove.
(dwarf_expr_context::get_reg_value): Move from
dwarf_evaluate_loc_desc.
(dwarf_expr_context::get_frame_base): Move from
dwarf_evaluate_loc_desc.
(dwarf_expr_context::execute_stack_op): Call frame context info
check. Remove use of read_addr_from_reg method.
* dwarf2/expr.h (struct dwarf_expr_context): Add frame info
member, read_addr_from_reg, get_reg_value and get_frame_base
declaration.
(read_addr_from_reg): Move to expr.c.
* dwarf2/frame.c (read_addr_from_reg): Move to
dwarf_expr_context.
(dwarf_expr_executor::read_addr_from_reg): Remove.
(dwarf_expr_executor::get_frame_base): Remove.
(dwarf_expr_executor::get_reg_value): Remove.
(execute_stack_op): Use read_addr_from_reg function instead of
read_addr_from_reg method.
* dwarf2/loc.c (dwarf_evaluate_loc_desc::get_frame_base): Move
to dwarf_expr_context.
(dwarf_evaluate_loc_desc::get_reg_value): Move to
dwarf_expr_context.
(dwarf_evaluate_loc_desc::read_addr_from_reg): Remove.
(dwarf2_locexpr_baton_eval):Use read_addr_from_reg function
instead of read_addr_from_reg method.
Move the initial values for dwarf_expr_context class data members
to the class declaration in expr.h.
gdb/ChangeLog:
* dwarf2/expr.c (dwarf_expr_context::dwarf_expr_context):
Remove initial data members values.
* dwarf2/expr.h (dwarf_expr_context): Add initial values
to the class data members.
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.
Evaluating DWARF expressions (such as location expressions) requires
knowing about the current objfile. For example, it may call functions
like dwarf2_fetch_die_loc_sect_off, which currently obtain the
dwarf2_per_objfile object it needs from the dwarf2_per_cu_data object.
However, since we are going to remove this
dwarf2_per_cu_data::dwarf2_per_objfile link, these functions will need
to obtain the current dwarf2_per_objfile by parmeter.
If we go up the stack, we see that the DWARF expression contexts
(dwarf_expr_context and the classes that derive from it) need to store
the dwarf2_per_objfile, to be able to pass it to those functions that
will need it.
This patch adds a constructor to all these dwarf_expr_context variants,
accepting a dwarf2_per_objfile parameter. This dwarf2_per_objfile
generally comes from a symbol baton created earlier.
For frame-related expressions, the dwarf2_per_objfile object must be
passed through the dwarf2_frame_cache object. This lead to the
dwarf2_frame_find_fde function returning (by parameter) a
dwarf2_per_objfile object. I then realized that this made the existing
"out_offset" parameter redundant. This offset is
`objfile->text_section_offset ()`, so it can be recomputed from the
dwarf2_per_objfile object at any time. I therefore opted to remove this
output parameter, as well as the offset field of dwarf2_frame_cache.
*Note*, there's one spot I'm particularly unsure about. In
dwarf_evaluate_loc_desc::push_dwarf_reg_entry_value, we would save and
overwrite the offset value in the context, along with a bunch of other
state. This is because we might be about to evaluate something in a
different CU that the current one. If the two CUs are in the same
objfile, then the text_offset is the same, as it's a property of the
objfile. However, if the two CUs are possibly in different objfiles,
then it means the text_offsets are different. It would also mean we
would need to save and restore the dwarf2_per_objfile in the context.
Is that even possible?
gdb/ChangeLog:
* dwarf2/expr.h (struct dwarf_expr_context)
<dwarf_expr_context>: Add dwarf2_per_objfile parameter.
<offset>: Remove.
<per_objfile>: New member.
* dwarf2/expr.c (dwarf_expr_context::dwarf_expr_context): Add
dwarf2_per_objfile parameter. Don't set offset, set
per_objfile.
(dwarf_expr_context::execute_stack_op): Use offset from objfile.
* dwarf2/frame.c (dwarf2_frame_find_fde): Return (by parameter)
a dwarf2_per_objfile object instead of an offset.
(class dwarf_expr_executor) <dwarf_expr_executor>: Add
constructor.
(execute_stack_op): Add dwarf2_per_objfile parameter, pass it
to dwarf2_expr_executor constructor. Don't set offset.
(dwarf2_fetch_cfa_info): Update.
(struct dwarf2_frame_cache) <text_offset>: Remove.
<per_objfile>: New field.
(dwarf2_frame_cache): Update.
(dwarf2_frame_prev_register): Update.
* dwarf2/loc.c (class dwarf_evaluate_loc_desc)
<dwarf_evaluate_loc_desc>: Add constructor.
(dwarf2_evaluate_loc_desc_full): Update.
(dwarf2_locexpr_baton_eval): Update.
(class symbol_needs_eval_context) <symbol_needs_eval_context>:
Add constructor.
(dwarf2_loc_desc_get_symbol_read_needs): Update.
Change-Id: I14df060669cc36ad04759f1708c6d7b1fda77727
