gdb represents a DW_TAG_variant_part as a union. While normally DWARF
would not set the size of a DW_TAG_variant_part, gdb's representation
requires the TYPE_LENGTH to be set.
This patch arranges to set the TYPE_LENGTH of a variant part if it has
not already been set.
This fixes some Rust regressions when testing against a version of
rustc that emits DW_TAG_variant_part.
gdb/ChangeLog
2018-08-31 Tom Tromey <tom@tromey.com>
* dwarf2read.c (dwarf2_add_field): Set the TYPE_LENGTH of the
variant part type.
This change sets BLOCK_RANGES for the block under consideration by
calling make_blockranges(). This action is performed in
dwarf2_record_block_ranges().
It should be noted that dwarf2_record_block_ranges() already does some
recording of the range via a call to record_block_range(). The ranges
recorded in that fashion end up in the address map associated with the
blockvector for the compilation unit's symtab. Given an address, the
addrmap provides a fast way of finding the block containing that
address. The address map does not, however, provide a convenient way
of determining which address ranges make up a particular block.
While reading a set of ranges, a vector of pairs is used to collect
the starting and ending addresses for each range in the block. Once
all of the ranges for a block have been collected, make_blockranges()
is called to fill in BLOCK_RANGES for the block.
The ranges are stored for the block in the order that they're read
from the debug info. For DWARF, the starting address of the first
range of the block will be the entry pc in cases where DW_AT_entry_pc
is not present. (Well, that would ideally be the case. At the moment
DW_AT_entry_pc is not being handled.)
gdb/ChangeLog:
* dwarf2read.c (dwarf2_record_block_ranges): Fill in BLOCK_RANGES
for block.
New in v3:
- Remove things related to the dwarf-5 format.
- Fix compilation on mingw (scoped_mmap.c).
GDB can generate indexes for DWARF debug information, which, when
integrated in the original binary, can speed up loading object files.
This can be done using the gdb-add-index script or directly by the
linker itself. However, not many people know about this. And even
among those who do, because it requires additional steps, I don't know a
lot of people who actually go through that trouble.
To help make using the DWARF index more transparent, this patch
introduces a DWARF index cache. When enabled, loading an index-less
binary in GDB will automatically save an index file in ~/.cache/gdb.
When loading that same object file again, the index file will be looked
up and used to load the DWARF index. You therefore get the benefit of
the DWARF index without having to do additional manual steps or
modifying your build system. When an index section is already present
in the file, GDB will prefer that one over looking up the cache.
When doing my edit-compile-debug cycle, I often debug multiple times the
same build, so the cache helps reducing the load time of the debug
sessions after the first one.
- The saved index file is exactly the same as the output of the "save
gdb-index" command. It is therefore the exact same content that would
be found in the .gdb_index or .debug_names section. We just leave it
as a standalone file instead of merging it in the binary.
- The cache is just a directory with files named after the object
file's build-id. It is not possible to save/load the index for an
object file without build-id in the cache.
- The cache uses the gdb index format. The problem with the dwarf-5
format is that we can generate an addendum to the .debug_str section
that you're supposed to integrate to the original binary. This
complicates a little bit loading the data from the cached index files,
so I would leave this for later.
- The size taken up by ~/.cache/gdb is not limited. I was thinking we
could add configurable limit (like ccache does), but that would come
after. Also, maybe a command to flush the cache.
- The cache is disabled by default. I think once it's been out there
and tested for a while, it could be turned on by default, so that
everybody can enjoy it.
- The code was made to follow the XDG specification: if the
XDG_CACHE_HOME environment variable, it is used, otherwise it falls
back to ~/.cache/gdb. It is possible to change it using "set
index-cache directory". On other OSes than GNU/Linux, ~/.cache may
not be the best place to put such data. On macOS it should probably
default to ~/Library/Caches/... On Windows, %LocalAppData%/... I
don't intend to do this part, but further patches are welcome.
- I think that we need to be careful that multiple instances of GDB
don't interfere with each other (not far fetched at all if you run GDB
in some automated script) and the cache is always coherent (either the
file is not found, or it is found and entirely valid). Writing the
file directly to its final location seems like a recipe for failure.
One GDB could read a file in the index while it is being written by
another GDB. To mitigate this, I made write_psymtabs_to_index write
to temporary files and rename them once it's done. Two GDB instances
writing the index for the same file should not step on each other's
toes (the last file to be renamed will stay). A GDB looking up a file
will only see a complete file or no file. Also, if GDB crashes while
generating the index file, it will leave a work-in-progress file, but
it won't be picked up by other instances looking up in the cache.
gdb/ChangeLog:
* common/pathstuff.h (get_standard_cache_dir): New.
* common/pathstuff.c (get_standard_cache_dir): New.
* build-id.h (build_id_to_string): New.
* dwarf-index-common.h (INDEX4_SUFFIX, INDEX5_SUFFIX,
DEBUG_STR_SUFFIX): Move to here.
* dwarf-index-write.c (INDEX4_SUFFIX, INDEX5_SUFFIX,
DEBUG_STR_SUFFIX): Move from there.
(write_psymtabs_to_index): Make non-static, add basename
parameter. Write to temporary files, rename when done.
(save_gdb_index_command): Adjust call to
write_psymtabs_to_index.
* dwarf2read.h (dwarf2_per_objfile) <index_cache_res>: New
field.
* dwarf2read.c (dwz_file) <index_cache_res>: New field.
(get_gdb_index_contents_from_cache): New.
(get_gdb_index_contents_from_cache_dwz): New.
(dwarf2_initialize_objfile): Read index from cache.
(dwarf2_build_psymtabs): Save to index.
* dwarf-index-cache.h: New file.
* dwarf-index-cache.c: New file.
* dwarf-index-write.h: New file.
gdb/testsuite/ChangeLog:
* boards/index-cache-gdb.exp: New file.
* gdb.dwarf2/index-cache.exp: New file.
* gdb.dwarf2/index-cache.c: New file.
* gdb.base/maint.exp: Check if we are using the index cache.
New in v3:
- Remove changed to dwarf-5 functions.
The read_gdb_index_from_section and read_debug_names_from_section
functions read the index content, as their names state, from sections of
object files. A following patch will make it possible to read index
content from standalone files.
This patch therefore decouples the code that reads the index content
from the code that processes that content. Functions
dwarf2_read_gdb_index and dwarf2_read_debug_names receive callbacks that
are responsible for providing the index contents (for both the main file
and the potential dwz file).
gdb/ChangeLog:
* dwarf2read.c (read_gdb_index_from_section): Rename to...
(read_gdb_index_from_buffer): ... this. Remove section
parameter, add buffer parameter.
(get_gdb_index_contents_ftype,
get_gdb_index_contents_dwz_ftype): New typedefs.
(dwarf2_read_gdb_index): Add callback parameters to get the
index contents.
(get_gdb_index_contents_from_section): New.
(dwarf2_initialize_objfile): Update call to
dwarf2_read_gdb_index.
PR symtab/16842 shows that gdb will crash when the user tries to
invoke "info address" of a template parameter.
The bug here is that dwarf2read.c does not set the symtab on the
template parameter symbols. This is pedantically correct, given that
the template symbols do not appear in a symtab. However, gdb
primarily uses the symtab backlink to find the symbol's objfile. So,
this patch simply sets the symtab on these symbols.
Tested by the buildbot.
gdb/ChangeLog
2018-08-02 Tom Tromey <tom@tromey.com>
PR symtab/16842.
* dwarf2read.c (read_func_scope): Set symtab on template parameter
symbols.
(process_structure_scope): Likewise.
gdb/testsuite/ChangeLog
2018-08-02 Tom Tromey <tom@tromey.com>
PR symtab/16842.
* gdb.cp/temargs.exp: Test "info address" of a template
parameter.
This patch finally makes partial symbols and partial symtabs
independent of the program space.
Specifically:
It changes add_psymbol_to_list to accept a section index, and changes
the psymbol readers to pass this. At the same time it removes the
code to add the objfile's section offset to the psymbol.
It adds an objfile argument to the psymtab textlow and texthigh
accessors and changes some code to use the raw variants instead.
It removes the "relocate" method from struct quick_symbol_functions,
as it is no longer needed any more.
It changes partial_symbol::address so that the relevant offset is now
applied at the point of use.
gdb/ChangeLog
2018-07-26 Tom Tromey <tom@tromey.com>
* dwarf-index-write.c (add_address_entry): Don't add objfile
offsets.
* dbxread.c (find_stab_function): Rename from
find_stab_function_addr. Return a bound_minimal_symbol.
(read_dbx_symtab): Use raw_text_low, raw_text_high.
Don't add objfile offsets.
(end_psymtab): Use raw_text_low, raw_text_high,
MSYMBOL_VALUE_RAW_ADDRESS.
(read_ofile_symtab): Update.
(process_one_symbol): Update.
* dwarf2read.c (create_addrmap_from_index): Don't add objfile
offsets.
(dw2_relocate): Remove.
(dw2_find_pc_sect_symtab): Bias PC by the text offset before
searching addrmap.
(dwarf2_gdb_index_functions, dwarf2_debug_names_functions):
Update.
(process_psymtab_comp_unit_reader, add_partial_symbol)
(add_partial_subprogram, dwarf2_ranges_read): Update.
(load_partial_dies): Update.
(add_address_entry): Don't add objfile offsets.
(dwarf2_build_include_psymtabs): Update.
(create_addrmap_from_aranges): Don't add objfile offsets.
(dw2_find_pc_sect_compunit_symtab): Update.
* mdebugread.c (parse_symbol): Don't add objfile offsets.
(parse_lines): Remove 'pst' parameter, replace with 'textlow'.
Update.
(parse_partial_symbols): Don't add objfile offsets. Use
raw_text_low, raw_text_high. Update.
(handle_psymbol_enumerators, psymtab_to_symtab_1): Update.
* objfiles.c (objfile_relocate1): Don't relocate psymtabs_addrmap
or call 'relocate' quick function. Clear psymbol_map.
* psympriv.h (struct partial_symbol) <address>: Add section
offset.
<set_unrelocated_address>: Rename from set_address.
<raw_text_low, raw_text_high>: New methods.
<text_low, text_high>: Add objfile parameter.
(add_psymbol_to_bcache): Add 'section' parameter. Call
set_unrelocated_address.
* psymtab.c (find_pc_sect_psymtab_closer, find_pc_sect_psymtab)
(find_pc_psymbol): Update.
(fixup_psymbol_section, relocate_psymtabs): Remove.
(dump_psymtab, psym_functions): Update.
(add_psymbol_to_bcache, add_psymbol_to_list): Add 'section'
parameter.
(maintenance_info_psymtabs, maintenance_check_psymtabs): Update.
(start_psymtab_common): Update.
* symfile-debug.c (debug_qf_relocate): Remove.
(debug_sym_quick_functions): Update.
* symfile.h (struct quick_symbol_functions) <relocate>: Remove.
* xcoffread.c (scan_xcoff_symtab): Don't add objfile offsets.
Update.
This introduces accessors for the partial symbol table textlow and
texthigh fields. This lets us later arrange to relocate these values
at their point of use.
I did this conversion by renaming the fields. I didn't rename the
fields back afterward, thinking that on the off chance that someone
has a patch touching this area, then a merge would helpfully break
their compile.
I looked at making the fields private, but this interferes with the
memset in allocate_psymtab, and I didn't want to chase this down.
This conversion can be done later if need be.
gdb/ChangeLog
2018-07-26 Tom Tromey <tom@tromey.com>
* dbxread.c (read_dbx_symtab, end_psymtab, read_ofile_symtab):
Update.
* dwarf2read.c (dwarf2_create_include_psymtab): Don't initialize
textlow and texthigh fields.
(process_psymtab_comp_unit_reader, dwarf2_build_include_psymtabs):
Update.
* mdebugread.c (parse_lines, parse_partial_symbols)
(psymtab_to_symtab_1): Update.
* psympriv.h (struct partial_symtab) <m_text_low, m_text_high>:
Rename fields. Update comment. Now private.
<text_low, text_high, set_text_low, set_text_high>: New methods.
* psymtab.c (find_pc_sect_psymtab_closer, find_pc_sect_psymtab)
(find_pc_sect_psymbol, relocate_psymtabs, dump_psymtab)
(start_psymtab_common, maintenance_info_psymtabs)
(maintenance_check_psymtabs): Update.
* xcoffread.c (xcoff_end_psymtab): Don't initialize textlow and
texthigh fields.
(scan_xcoff_symtab): Update.
Add a maintenance command to disable the DWARF stack unwinders.
Normal users would not need this feature, but it is useful to allow
extended testing of fallback stack unwinding strategies, for example,
prologue scanners.
This is a partial implementation of the idea discussed in pr gdb/8434,
which talks about a generic ability to disable any frame unwinder.
Being able to arbitrarily disable any frame unwinder would be a more
complex patch, and I was unsure how useful such a feature would really
be, however, I can see (and have) a real need to disable DWARF
unwinders. That's why this patch only targets that specific set of
unwinders.
If in the future we find ourselves adding more switches to disable
different unwinders, then we should probably move to a more generic
solution, and remove this patch.
gdb/ChangeLog:
* dwarf2-frame-tailcall.c (tailcall_frame_sniffer): Exit early if
DWARF unwinders are disabled.
* dwarf2-frame.c: Add dwarf2read.h include.
(dwarf2_frame_sniffer): Exit early if DWARF unwinders are
disabled.
(dwarf2_frame_unwinders_enabled_p): Define.
(show_dwarf_unwinders_enabled_p): New function.
(_initialize_dwarf2_frame): Register switch to control DWARF
unwinder use.
* dwarf2-frame.h (dwarf2_frame_unwinders_enabled_p): Declare.
* dwarf2read.c (set_dwarf_cmdlist): Remove static keyword.
(show_dwarf_cmdlist): Remove static keyword.
* dwarf2read.h (set_dwarf_cmdlist): Declare.
(show_dwarf_cmdlist): Declare.
* NEWS: Document new feature.
gdb/doc/ChangeLog:
* gdb.texinfo (Maintenance Commands): Add description of
maintenance command to control dwarf unwinders.
gdb/testsuite/ChangeLog:
* gdb.base/maint.exp: Add check that dwarf unwinders control flag
is visible.
This patch generates a warning if DW_AT_upper_bound or DW_AT_count is defined,
but can't be translated. This is triggered for current gcc in lto mode for
vla test-cases.
Build and reg-tested on x86_64-linux.
2018-07-26 Tom de Vries <tdevries@suse.de>
* dwarf2read.c (read_subrange_type): Warn if DW_AT_upper_bound or
DW_AT_count can't be translated to a dynamic prop.
This patch is another attempt at really fixing the multitude of assertions
being seen where symbols of one language are being added to symbol lists of
another language.
In this specific case, the backtrace command (thread apply all bt full) that
is looking for the compunit containing the PC of the thread. That calls
get_prev_frame several times. This function calls (eventually)
dwarf2_frame_prev_register. That eventually ends up calling
find_pc_compunit_symtab.
In this function (find_pc_sect_compunit_symtab actually), we loop over all
compunits, calling the "quick" function dw2_find_pc_sect_compunit_symtab.
That function calls dw2_instantiate_symtab to read in all the CU's symbols.
Now the fun begins.
dw2_do_instantiate_symtab queues the per_cu for reading, using a default
"pretend" language of language_minimal with the expectation that this will
be set later.
The DIEs of this (only queued) CU are then processed.
The first DIE is DW_TAG_compile_unit. That's handled by read_file_scope.
(Nearly) The first thing read_file_scope does is:
get_scope_pc_bounds (die, &lowpc, &highpc, cu);
This function loops over the children of the current DIE (a compile_unit),
looking for bounds. The first such child is a subprogram, and we attempt to
get its bounds. We use dwarf2_attr to get at DW_AT_high_pc.
This subprogram has DW_AT_specification set, so dwarf_attr (via
follow_die_ref/follow_die_offset) will follow that, but follow_die_offset
*also* attempts to load the containing CU for the spec DIE. That spec DIE
lives inside a CU that is a partial_unit and has no language attribute. So
it simply inherits the language from the CU that elicited the read. [That
all happens in follow_die_offset.]
The original CU's language is still language_minimal -- we haven't gotten to
the line in read_file_scope that actually sets the language yet!
And that is the cause of these problems. The call to prepare_one_comp_unit
needs to be the *first* thing that is done when reading a CU so that the
CU's language can be recorded (and inherited by any referenced
partial_units).
Since a test reproducer for this has been so elusive, this patch also adds a
wrapper function around add_symbol_to_list which asserts when adding a
symbol of one language to a list containing symbols of a different language.
gdb/ChangeLog:
2017-07-24 Keith Seitz <keiths@redhat.com>
PR symtab/23010
* dwarf2read.c (dw2_add_symbol_to_list): New function.
(fixup_go_packaging, new_symbol): Use dw2_add_symbol_to_list
instead of add_symbol_to_list.
(read_file_scope): Call prepare_one_comp_unit before reading
any other DIEs.
This converts the DWARF reader to use the new-style buildsym API. A
new buildsym_compunit is created for each CU and is used to construct
the symbol table. In some cases the CU must be passed to functions
which previously did not accept it. FWIW I tend to think that most
methods in the DWARF reader ought to be methods on the dwarf2_cu
object.
gdb/ChangeLog
2018-07-20 Tom Tromey <tom@tromey.com>
* dwarf2read.c: Include buildsym.h.
(struct dwarf2_cu) <builder>: New method.
(fixup_go_packaging): Update.
(process_full_comp_unit, process_full_type_unit): Update. Don't
use scoped_free_pendings.
(using_directives): Add "cu" parameter, remove "language".
(read_import_statement, setup_type_unit_groups, )
(read_func_scope, read_lexical_block_scope)
(dwarf2_record_block_ranges, read_namespace): Update.
(lnp_state_machine::lnp_state_machine): Add cu parameter.
(lnp_state_machine::handle_end_sequence): Update.
(class lnp_state_machine) <m_cu>: New member.
<m_record_line_callback>: Remove.
<m_currently_recording_lines>: New member.
(lnp_state_machine::handle_set_file): Update.
(noop_record_line): Remove.
(dwarf_record_line_p): Add cu parameter.
(dwarf_record_line_1, dwarf_finish_line): Likewise.
(lnp_state_machine::record_line)
(lnp_state_machine::lnp_state_machine)
(lnp_state_machine::check_line_address, dwarf_decode_lines_1)
(dwarf_decode_lines): Update.
(dwarf2_start_subfile): Add cu parameter.
(dwarf2_start_symtab, new_symbol): Update.
(macro_start_file, dwarf_decode_macro_bytes): Add cu parameter.
Remove dwarf2_per_objfile parameter.
(dwarf_decode_macros): Update.
This changes cp_scan_for_anonymous_namespaces to use the
buildsym_compunit API, rather than the function-based API.
gdb/ChangeLog
2018-07-20 Tom Tromey <tom@tromey.com>
* stabsread.c (define_symbol): Update.
* buildsym-legacy.h (get_buildsym_compunit): Declare.
* dwarf2read.c (new_symbol): Update.
* cp-support.h (cp_scan_for_anonymous_namespaces): Update.
* cp-namespace.c: Include buildsym.h.
(cp_scan_for_anonymous_namespaces): Add "compunit" parameter.
* buildsym-legacy.c (get_buildsym_compunit): New function.
This introduces a new header, buildsym-legacy.h, and changes all the
symbol readers to use it. The idea is to put the function-based
interface, that relies on the buildsym_compunit global, into a
separate header. Then when a symbol reader is updated to use the new
interface, it can simply not include buildsym-legacy.h, so it's easy
to be sure that the new API is used everywhere.
gdb/ChangeLog
2018-07-20 Tom Tromey <tom@tromey.com>
* xcoffread.c: Include buildsym-legacy.h.
* windows-nat.c: Include buildsym-legacy.h.
* stabsread.c: Include buildsym-legacy.h.
* mdebugread.c: Include buildsym-legacy.h.
* buildsym-legacy.h: New file.
* buildsym-legacy.c: New file, from buildsym.c.
* go32-nat.c: Include buildsym-legacy.h.
* dwarf2read.c: Include buildsym-legacy.h.
* dbxread.c: Include buildsym-legacy.h.
* cp-namespace.c: Include buildsym-legacy.h.
* coffread.c: Include buildsym-legacy.h.
* buildsym.h: Move some contents to buildsym-legacy.h.
* buildsym.c: Include buildsym-legacy.h. Move many functions to
buildsym-legacy.c.
* Makefile.in (HFILES_NO_SRCDIR): Add buildsym-legacy.h.
Currently the DWARF reader sets the list_in_scope member of the CU
when first starting to process symbols. Future changes will make this
assert -- code will not be able to refer to these lists until after
start_symtab has been called. This patch prepares for the problem by
arranging to initialize list_in_scope in dwarf2_start_symtab.
gdb/ChangeLog
2018-07-20 Tom Tromey <tom@tromey.com>
* dwarf2read.c (process_full_comp_unit): Do not set list_in_scope.
(process_full_type_unit): Likewise.
(dwarf2_start_symtab): Set list_in_scope.
The DWARF reader was setting the list_in_scope member when reading
partial symbols. however, this member is only useful when reading
full symbols. Future patches will make this assert, so remove these
unneeded initializations.
gdb/ChangeLog
2018-07-20 Tom Tromey <tom@tromey.com>
* dwarf2read.c (process_psymtab_comp_unit_reader)
(build_type_psymtabs_reader): Do not set list_in_scope.
This moves the context stack globals to be members of
buildsym_compunit, changing the type to a std::vector in the process.
Because the callers expect the context stack object to be valid after
being popped, at Simon's suggestion I've changed pop_context to return
the object rather than the pointer.
gdb/ChangeLog
2018-07-20 Tom Tromey <tom@tromey.com>
* coffread.c (coff_symtab_read): Update.
* xcoffread.c (read_xcoff_symtab): Update.
* dwarf2read.c (new_symbol): Update.
(read_func_scope, read_lexical_block_scope): Update.
* dbxread.c (process_one_symbol): Update.
* buildsym.h (context_stack, context_stack_depth): Don't declare.
(outermost_context_p): Remove macro.
(outermost_context_p, get_current_context_stack)
(get_context_stack_depth): Declare.
(pop_context): Return struct context_stack.
* buildsym.c (struct buildsym_compunit) <m_context_stack: New
member.
(context_stack_size): Remove.
(INITIAL_CONTEXT_STACK_SIZE): Remove.
(prepare_for_building, end_symtab_get_static_block)
(augment_type_symtab, push_context): Update.
(pop_context): Return struct context_stack.
(outermost_context_p, get_current_context_stack)
(get_context_stack_depth): New functions.
(buildsym_init): Update.
This changes a few explicit checks of context_stack_depth to use
outermost_context_p instead. This simplifies some future work.
gdb/ChangeLog
2018-07-16 Tom Tromey <tom@tromey.com>
* xcoffread.c (read_xcoff_symtab): Use outermost_context_p.
* dwarf2read.c (using_directives, new_symbol): Use
outermost_context_p.
* dbxread.c (process_one_symbol): Use outermost_context_p.
* coffread.c (coff_symtab_read): Use outermost_context_p.
processing_gcc is also only used by stabsread -- it is set by the
DWARF reader, but this turns out not to be needed. So, this patch
moves processing_gcc and removes the assignment from the DWARF reader.
gdb/ChangeLog
2018-07-16 Tom Tromey <tom@tromey.com>
* stabsread.h (processing_gcc_compilation): Move from buildsym.h.
* dwarf2read.c (dwarf2_start_symtab): Don't set
processing_gcc_compilation.
* buildsym.h (processing_gcc_compilation): Move to stabsread.h.
The version check of the dwarf compilation unit header in
error_check_comp_unit_head is done too late, and consequently dwarf code with
an unsupported version in the compilation unit header is interpreted as dwarf5
code in read_comp_unit_head.
Fixed by moving the check earlier.
Build and reg-tested on x86_64-linux.
2018-07-04 Tom de Vries <tdevries@suse.de>
* dwarf2read.c (error_check_comp_unit_head): Move dwarf version
check ...
(read_comp_unit_head): ... here.
* gdb.dwarf2/dw2-error.exp: Update expected error message.
I noticed that dwarf2_free_objfile can be made static, by changing it
to be a registry cleanup function. This simplifies the code, as well,
because now symbol readers don't have to explicitly call it.
Tested by the buildbot.
gdb/ChangeLog
2018-06-28 Tom Tromey <tom@tromey.com>
* coffread.c (coff_symfile_finish): Update.
* xcoffread.c (xcoff_symfile_finish): Update.
* elfread.c (elf_symfile_finish): Update.
* symfile.h (dwarf2_free_objfile): Don't declare.
* dwarf2read.c (_initialize_dwarf2_read): Use
register_objfile_data_with_cleanup.
(dwarf2_free_objfile): Now static. Change signature.
This patch fixes a unique condition where GDB fails to provide line
information of symbol at address zero when code is compiled with text
address zero but loaded at an offset > 0.
For example lets compile following code snippet:
int main() {
return 0;
}
gcc -O0 -g3 -nostdlib -emain -Wl,-Ttext=0x00 -o file.out file.c
Start gdb and run:
add-symbol-file file.out 0xffff0000
info line main
GDB will return error saying no line info is available for the symbol.
This is a direct consequence of the fix for PR 12528 where GDB tries to ignore
line table for a function which has been garbage collected by the linker.
As the garbage collected symbols are sent to address zero GDB assumes a symbol
actually placed at address zero as garbage collected.
This was fixed with an additional check address < lowpc. But when symbol is
loaded at an offset lowpc becomes lowpc + offset while no offset is added to
address rather final symbol address is calculated based on baseaddr and address
added together. So in case where symbols are loaded at an offset the condition
address < lowpc will always return true.
This patch fixes this by comparing address against a non offset lowpc.
This patch also adds a GDB test case to replicate this behavior.
gdb:
2018-06-27 Omair Javaid <omair.javaid@linaro.org>
PR gdb/21695
* dwarf2read.c (lnp_state_machine::check_line_address): Update declaration.
(dwarf_decode_lines_1): Adjust.
gdb/testsuite:
2018-06-27 Omair Javaid <omair.javaid@linaro.org>
PR gdb/21695
* gdb.base/infoline-reloc-main-from-zero.exp: New test.
* gdb.base/infoline-reloc-main-from-zero.c: New file.
Since we now have two index formats, DWARF5/debug_names and gdb_index, I
wanted to rename some functions to make it clear that they deal with the
gdb_index format specifically.
gdb/ChangeLog:
* dwarf2read.c (read_index_from_section): Rename to...
(read_gdb_index_from_section): ... this, update all callers.
(dwarf2_read_index): Rename to...
(dwarf2_read_gdb_index): ... this, update all callers.
GCC 6.3.0 produces this kind of errors:
CXX dwarf2read.o
/home/simark/src/binutils-gdb/gdb/dwarf2read.c: In function 'void process_cu_includes(dwarf2_per_objfile*)':
/home/simark/src/binutils-gdb/gdb/dwarf2read.c:10220:8: error: types may not be defined in a for-range-declaration [-Werror]
for (struct dwarf2_per_cu_data *iter : dwarf2_per_objfile->just_read_cus)
^~~~~~
Removing the struct keyword makes it happy.
gdb/ChangeLog:
* dwarf2read.c (process_cu_includes): Remove struct keyword.
* serial.c (serial_interface_lookup): Remove struct keyword.
This removes a VEC from dwarf2read.c, replacing it with a std::vector.
Tested by the buildbot.
gdb/ChangeLog
2018-06-09 Tom Tromey <tom@tromey.com>
* dwarf2read.c (process_cu_includes): Update.
(process_full_comp_unit): Update.
* dwarf2read.h (struct dwarf2_per_objfile) <just_read_cus>: Now a
std::vector.
TYPE_TAG_NAME has been an occasional source of confusion and bugs. It
seems to me that it is only useful for C and C++ -- but even there,
not so much, because at least with DWARF there doesn't seem to be any
way to wind up with a type where the name and the tag name are both
non-NULL and different.
So, this patch removes TYPE_TAG_NAME entirely. This should save a
little memory, but more importantly, it simplifies this part of gdb.
A few minor test suite adjustments were needed. In some situations
the new code does not yield identical output to the old code.
gdb/ChangeLog
2018-06-01 Tom Tromey <tom@tromey.com>
* valops.c (enum_constant_from_type, value_namespace_elt)
(value_maybe_namespace_elt): Update.
* valarith.c (find_size_for_pointer_math): Update.
* target-descriptions.c (make_gdb_type): Update.
* symmisc.c (print_symbol): Update.
* stabsread.c (define_symbol, read_type)
(complain_about_struct_wipeout, add_undefined_type)
(cleanup_undefined_types_1): Update.
* rust-lang.c (rust_tuple_type_p, rust_slice_type_p)
(rust_range_type_p, val_print_struct, rust_print_struct_def)
(rust_internal_print_type, rust_composite_type)
(rust_evaluate_funcall, rust_evaluate_subexp)
(rust_inclusive_range_type_p): Update.
* python/py-type.c (typy_get_tag): Update.
* p-typeprint.c (pascal_type_print_base): Update.
* mdebugread.c (parse_symbol, parse_type): Update.
* m2-typeprint.c (m2_long_set, m2_record_fields, m2_enum):
Update.
* guile/scm-type.c (gdbscm_type_tag): Update.
* go-lang.c (sixg_string_p): Update.
* gnu-v3-abi.c (build_gdb_vtable_type, build_std_type_info_type):
Update.
* gdbtypes.h (struct main_type) <tag_name>: Remove.
(TYPE_TAG_NAME): Remove.
* gdbtypes.c (type_name_no_tag): Simplify.
(check_typedef, check_types_equal, recursive_dump_type)
(copy_type_recursive, arch_composite_type): Update.
* f-typeprint.c (f_type_print_base): Update. Print "Type" prefix
in summary mode when needed.
* eval.c (evaluate_funcall): Update.
* dwarf2read.c (fixup_go_packaging, read_structure_type)
(process_structure_scope, read_enumeration_type)
(read_namespace_type, read_module_type, determine_prefix): Update.
* cp-support.c (inspect_type): Update.
* coffread.c (process_coff_symbol, decode_base_type): Update.
* c-varobj.c (c_is_path_expr_parent): Update.
* c-typeprint.c (c_type_print_base_struct_union): Update.
(c_type_print_base_1): Update. Print struct/class/union/enum in
summary when using C language.
* ax-gdb.c (gen_struct_ref, gen_namespace_elt)
(gen_maybe_namespace_elt): Update.
* ada-lang.c (ada_type_name): Simplify.
(empty_record, ada_template_to_fixed_record_type_1)
(template_to_static_fixed_type)
(to_record_with_fixed_variant_part, ada_check_typedef): Update.
gdb/testsuite/ChangeLog
2018-06-01 Tom Tromey <tom@tromey.com>
* gdb.xml/tdesc-regs.exp (load_description): Update expected
results.
* gdb.dwarf2/method-ptr.exp: Set language to C++.
* gdb.dwarf2/member-ptr-forwardref.exp: Set language to C++.
* gdb.cp/typeid.exp (do_typeid_tests): Update type_re.
* gdb.base/maint.exp (maint_pass_if): Update.
Currently dwarf2read.c will pass the CU's language to
c_type_print_args -- but this doesn't affect all aspects of type
printing, because some code in c-typeprint.c refers to
current_language.
This patch threads the language through more of the type printing
code, adding an overload to c_type_print. Some uses of
current_language remain, but now they are only in top-level functions.
gdb/ChangeLog
2018-06-01 Tom Tromey <tom@tromey.com>
* dwarf2read.c (dwarf2_compute_name): Pass CU's language to
c_print_type.
* c-typeprint.c (c_print_type_1): Add "language" parameter.
(c_print_type): Update.
(c_print_type): New overload.
(c_type_print_varspec_prefix, c_type_print_args)
(c_type_print_varspec_suffix, c_print_type_no_offsets)
(c_type_print_base_struct_union, c_type_print_base_1)
(cp_type_print_method_args): Add "language" parameter.
(c_type_print_base): Update.
* c-lang.h (c_print_type): Add new overload.
I get this kind of errors with GCC 6.3.0:
/home/simark/src/binutils-gdb/gdb/breakpoint.c: In function 'void print_solib_event(int)':
/home/simark/src/binutils-gdb/gdb/breakpoint.c:4618:12: error: types may not be defined in a for-range-declaration [-Werror]
for (struct so_list *iter : current_program_space->added_solibs)
^~~~~~
Removing the struct keyword makes it happy.
gdb/ChangeLog:
* breakpoint.c (print_solib_event, check_status_catch_solib):
Remove struct keyword in range-based for loops.
* dbxread.c (find_corresponding_bincl_psymtab): Likewise.
* dwarf2read.c (compute_delayed_physnames, rust_union_quirks);
Likewise.
* linespec.c (find_superclass_methods, search_minsyms_for_name):
Likewise.
* symfile.c (addr_info_make_relative): Likewise.
* thread.c (value_in_thread_stack_temporaries): Likewise.
This changes dwarf2_read_debug_names to use std::unique_ptr from the
outset. This simplifies the code that installs the resulting map into
dwarf2_per_objfile.
Tested by the buildbot.
ChangeLog
2018-05-21 Tom Tromey <tom@tromey.com>
* dwarf2read.c (dwarf2_read_debug_names): Use std::unique_ptr.
(mapped_index_base): Use DISABLE_COPY_AND_ASSIGN. Default
constructor.
This adds a constructor to struct dwz_file and arranges for it to be
allocated with "new" and wrapped in a unique_ptr. This cuts down on
the amount of manual memory management that must be done.
Regression tested by the buildbot.
gdb/ChangeLog
2018-05-18 Tom Tromey <tom@tromey.com>
* dwarf2read.c (struct dwz_file): Add constructor, initializers.
<dwz_bfd>: Now a gdb_bfd_ref_ptr.
(~dwarf2_per_objfile): Update
(dwarf2_get_dwz_file): Use new.
* dwarf2read.h (struct dwarf2_per_objfile) <dwz_file>: Now a
unique_ptr.
This adds a constructor and initializer to dwp_file and changes it to
be allocated with "new". This removes a bit of manual refcount
management.
Tested by the buildbot.
gdb/ChangeLog
2018-05-18 Tom Tromey <tom@tromey.com>
* dwarf2read.h (struct dwarf2_per_objfile) <dwp_file>: Now a
unique_ptr.
* dwarf2read.c (struct dwp_file): Add constructor and
initializers.
(open_and_init_dwp_file): Return a unique_ptr.
(dwarf2_per_objfile, create_dwp_hash_table)
(create_dwo_unit_in_dwp_v1, create_dwo_unit_in_dwp_v2)
(lookup_dwo_unit_in_dwp): Update.
(open_and_init_dwp_file, get_dwp_file): Update.
This changes struct mapped_index to be allocated with new. This
simplifies the creation a bit (see dwarf2_read_index) and also removes
a somewhat ugly explicit destructor call from ~dwarf2_per_objfile.
Tested by the buildbot.
gdb/ChangeLog
2018-05-18 Tom Tromey <tom@tromey.com>
* dwarf2read.c (dwarf2_per_objfile): Update.
(struct mapped_index): Add initializers.
(dwarf2_read_index): Use new.
(dw2_symtab_iter_init): Update.
* dwarf2read.h (struct dwarf2_per_objfile) <index_table>: Now a
unique_ptr.
PR symtab/23010 reports a crash that occurs when using -readnow
on a dwz-generated debuginfo file.
The crash occurs because the DWARF has a partial CU with no language
set, and then a full CU that references this partial CU using
DW_AT_abstract_origin.
In this case, the partial CU is read by dw2_expand_all_symtabs using
language_minimal; but then this conflicts with the creation of the
block's symbol table in the C++ CU.
This patch fixes the problem by arranging for partial CUs not to be
read by -readnow. I tend to think that it doesn't make sense to read
a partial CU in isolation -- they should only be read when imported
into some other CU.
In conjunction with some other patches I am going to post, this also
fixes the Rust -readnow crash that Jan reported.
There are two problems with this patch:
1. It is difficult to reason about. There are many cases where I've
patched the code to call init_cutu_and_read_dies with the flag set
to "please do read partial units" -- but I find it difficult to be
sure that this is always correct.
2. It is still missing a standalone test case. This seemed hard.
2018-05-17 Tom Tromey <tom@tromey.com>
PR symtab/23010:
* dwarf2read.c (load_cu, dw2_do_instantiate_symtab)
(dw2_instantiate_symtab): Add skip_partial parameter.
(dw2_find_last_source_symtab, dw2_map_expand_apply)
(dw2_lookup_symbol, dw2_expand_symtabs_for_function)
(dw2_expand_all_symtabs, dw2_expand_symtabs_with_fullname)
(dw2_expand_symtabs_matching_one)
(dw2_find_pc_sect_compunit_symtab)
(dw2_debug_names_lookup_symbol)
(dw2_debug_names_expand_symtabs_for_function): Update.
(init_cutu_and_read_dies): Add skip_partial parameter.
(process_psymtab_comp_unit, build_type_psymtabs_1)
(process_skeletonless_type_unit, load_partial_comp_unit)
(psymtab_to_symtab_1): Update.
(load_full_comp_unit): Add skip_partial parameter.
(process_imported_unit_die, dwarf2_read_addr_index)
(follow_die_offset, dwarf2_fetch_die_loc_sect_off)
(dwarf2_fetch_constant_bytes, dwarf2_fetch_die_type_sect_off)
(read_signatured_type): Update.
It turns out that a dwarf2_cu can remain allocated after psymtab
expansion is done, and so it makes sense to clear rust_unions when
done processing it.
Tested on x86-64 Fedora 27.
2018-05-14 Tom Tromey <tom@tromey.com>
* dwarf2read.c (rust_union_quirks): Clear rust_unions.
This adds some basic type alignment support to gdb. It changes struct
type to store the alignment, and updates dwarf2read.c to handle
DW_AT_alignment. It also adds a new gdbarch method and updates
i386-tdep.c.
None of this new functionality is used anywhere yet, so tests will
wait until the next patch.
2018-04-30 Tom Tromey <tom@tromey.com>
* i386-tdep.c (i386_type_align): New function.
(i386_gdbarch_init): Update.
* gdbarch.sh (type_align): New method.
* gdbarch.c, gdbarch.h: Rebuild.
* arch-utils.h (default_type_align): Declare.
* arch-utils.c (default_type_align): New function.
* gdbtypes.h (TYPE_ALIGN_BITS): New define.
(struct type) <align_log2>: New field.
<instance_flags>: Now a bitfield.
(TYPE_RAW_ALIGN): New macro.
(type_align, type_raw_align, set_type_align): Declare.
* gdbtypes.c (type_align, type_raw_align, set_type_align): New
functions.
* dwarf2read.c (quirk_rust_enum): Set type alignment.
(get_alignment, maybe_set_alignment): New functions.
(read_structure_type, read_enumeration_type, read_array_type)
(read_set_type, read_tag_pointer_type, read_tag_reference_type)
(read_subrange_type, read_base_type): Set type alignment.
I noticed the existence of -Wsuggest-override and so this patch
enables it for gdb. It found a few spots that could use "override".
Also I went ahead and removed all uses of the "OVERRIDE" macro.
Using override is beneficial because it makes it harder to change a
base class and then forget to change a derived class.
Tested by the buildbot.
ChangeLog
2018-04-27 Tom Tromey <tom@tromey.com>
* configure: Rebuild.
* warning.m4 (AM_GDB_WARNINGS): Add -Wsuggest-override.
* dwarf2loc.c (class dwarf_evaluate_loc_desc): Use "override", not
"OVERRIDE".
(class symbol_needs_eval_context): Likewise.
* dwarf2read.c (mock_mapped_index::symbol_name_count)
(mock_mapped_index::symbol_name_at): Use "override". Remove
"virtual".
* dwarf2-frame.c (dwarf_expr_executor::get_addr_index): Use
"override".
(class dwarf_expr_executor): Use "override", not "OVERRIDE".
* aarch64-tdep.c (instruction_reader::read): Use "override".
(instruction_reader_test::read): Likewise.
* arm-tdep.c (instruction_reader::read): Use "override".
(instruction_reader_thumb::read): Likewise.
gdbserver/ChangeLog
2018-04-27 Tom Tromey <tom@tromey.com>
* configure: Rebuild.
While debugging the crash that Jan reported, I noticed that in some
situations we could end up with a situation where one branch of a Rust
enum type ended up with a field count of -1.
The fix is simple: only conditionally drop the discriminant field when
rewriting the enum variants.
I couldn't find a way to test this; I only noticed it while debugging
the DWARF reader.
2018-04-17 Tom Tromey <tom@tromey.com>
* dwarf2read.c (quirk_rust_enum): Conditionally drop the
discriminant field.
I noticed that quirk_rust_enum can crash when presented with a union
whose fields are all scalar types.
This patch adds a new test case and fixes the bug.
Regression tested on Fedora 26 x86-64.
2018-04-17 Tom Tromey <tom@tromey.com>
* dwarf2read.c (quirk_rust_enum): Handle unions correctly.
2018-04-17 Tom Tromey <tom@tromey.com>
* gdb.rust/simple.rs (Union): New type.
(main): New local "u".
* gdb.rust/simple.exp (test_one_slice): Add new test case.
Tom Tromey
Kevin Buettner
Simon Marchi
Andrew Burgess
Tom de Vries
Keith Seitz
Omair Javaid
Simon Marchi