From: Aaron Merey <amerey@redhat.com>
To: gdb-patches@sourceware.org
Cc: Tom Tromey <tom@tromey.com>
Subject: [PING*2][PATCH 7/7 v2] gdb/debuginfod: Add .debug_line downloading
Date: Tue, 9 May 2023 09:49:50 -0400 [thread overview]
Message-ID: <CAJDtP-TwoPGwTmhtqHKhdtpJ40pPzvtSVRzcFEw_PSvf98EABQ@mail.gmail.com> (raw)
In-Reply-To: <CAJDtP-RmHky-DUh1o5FPqfSAmR3+b57W6y1-oJvVPkgxvjr+uQ@mail.gmail.com>
Ping
Thanks,
Aaron
On Tue, May 2, 2023 at 10:25 AM Aaron Merey <amerey@redhat.com> wrote:
>
> Ping
>
> Thanks,
> Aaron
>
> On Mon, Apr 17, 2023 at 2:07 PM Aaron Merey <amerey@redhat.com> wrote:
> >
> > v1 can be found here:
> > https://sourceware.org/pipermail/gdb-patches/2023-February/197459.html
> >
> > v2 merges dwarf_decode_line_header_separate with
> > dwarf_decode_line_header and read_formatted_entries_separate with
> > read_formatted_entries in order to reduce code duplication.
> >
> > ---
> >
> > 'set debuginfod enabled lazy' allows gdb to download .gdb_index files in
> > order to defer full debuginfo downloads. However .gdb_index does not
> > contain any information regarding source filenames. When a gdb command
> > includes a filename argument (ex. 'break main.c:50'), this results in
> > the mass downloading of all deferred debuginfo so gdb can search the
> > debuginfo for matching source filenames. This can result in unnecessary
> > downloading.
> >
> > To improve this, have gdb instead download each debuginfo's .debug_line
> > (and .debug_line_str if using DWARF5) when executing these commands.
> > Download full debuginfo only when its .debug_line contains a matching
> > filename.
> >
> > Since the combined size of .debug_line and .debug_line_str is only about
> > 1% the size of the corresponding debuginfo, significant time can be saved
> > by checking these sections before choosing to download a deferred debuginfo.
> > ---
> > gdb/dwarf2/line-header.c | 215 +++++++++++++++++++++++-------------
> > gdb/dwarf2/line-header.h | 10 ++
> > gdb/dwarf2/read-gdb-index.c | 27 +++++
> > gdb/dwarf2/read.c | 165 +++++++++++++++++++++++++++
> > gdb/dwarf2/read.h | 31 ++++++
> > 5 files changed, 371 insertions(+), 77 deletions(-)
> >
> > diff --git a/gdb/dwarf2/line-header.c b/gdb/dwarf2/line-header.c
> > index 9d74c8fe75b..5eaff9c5a48 100644
> > --- a/gdb/dwarf2/line-header.c
> > +++ b/gdb/dwarf2/line-header.c
> > @@ -102,50 +102,57 @@ read_checked_initial_length_and_offset (bfd *abfd, const gdb_byte *buf,
> > {
> > LONGEST length = read_initial_length (abfd, buf, bytes_read);
> >
> > - gdb_assert (cu_header->initial_length_size == 4
> > - || cu_header->initial_length_size == 8
> > - || cu_header->initial_length_size == 12);
> > + if (cu_header != nullptr)
> > + {
> > + gdb_assert (cu_header->initial_length_size == 4
> > + || cu_header->initial_length_size == 8
> > + || cu_header->initial_length_size == 12);
> >
> > - if (cu_header->initial_length_size != *bytes_read)
> > - complaint (_("intermixed 32-bit and 64-bit DWARF sections"));
> > + if (cu_header->initial_length_size != *bytes_read)
> > + complaint (_("intermixed 32-bit and 64-bit DWARF sections"));
> > + }
> >
> > *offset_size = (*bytes_read == 4) ? 4 : 8;
> > return length;
> > }
> >
> > -/* Read directory or file name entry format, starting with byte of
> > - format count entries, ULEB128 pairs of entry formats, ULEB128 of
> > - entries count and the entries themselves in the described entry
> > - format. */
> > +
> > +/* Like read_formatted_entries but the .debug_line and .debug_line_str
> > + are stored in LINE_BUFP and LINE_STR_DATA. This is used for cases
> > + where these sections are read from separate files without necessarily
> > + having access to the entire debuginfo file they originate from. */
> >
> > static void
> > -read_formatted_entries (dwarf2_per_objfile *per_objfile, bfd *abfd,
> > - const gdb_byte **bufp, struct line_header *lh,
> > - unsigned int offset_size,
> > - void (*callback) (struct line_header *lh,
> > - const char *name,
> > - dir_index d_index,
> > - unsigned int mod_time,
> > - unsigned int length))
> > +read_formatted_entries
> > + (bfd *parent_bfd, const gdb_byte **line_bufp,
> > + const gdb::array_view<const gdb_byte> line_str_data,
> > + struct line_header *lh,
> > + unsigned int offset_size,
> > + void (*callback) (struct line_header *lh,
> > + const char *name,
> > + dir_index d_index,
> > + unsigned int mod_time,
> > + unsigned int length))
> > {
> > gdb_byte format_count, formati;
> > ULONGEST data_count, datai;
> > - const gdb_byte *buf = *bufp;
> > + const gdb_byte *buf = *line_bufp;
> > + const gdb_byte *str_buf = line_str_data.data ();
> > const gdb_byte *format_header_data;
> > unsigned int bytes_read;
> >
> > - format_count = read_1_byte (abfd, buf);
> > + format_count = read_1_byte (parent_bfd, buf);
> > buf += 1;
> > format_header_data = buf;
> > for (formati = 0; formati < format_count; formati++)
> > {
> > - read_unsigned_leb128 (abfd, buf, &bytes_read);
> > + read_unsigned_leb128 (parent_bfd, buf, &bytes_read);
> > buf += bytes_read;
> > - read_unsigned_leb128 (abfd, buf, &bytes_read);
> > + read_unsigned_leb128 (parent_bfd, buf, &bytes_read);
> > buf += bytes_read;
> > }
> >
> > - data_count = read_unsigned_leb128 (abfd, buf, &bytes_read);
> > + data_count = read_unsigned_leb128 (parent_bfd, buf, &bytes_read);
> > buf += bytes_read;
> > for (datai = 0; datai < data_count; datai++)
> > {
> > @@ -154,10 +161,10 @@ read_formatted_entries (dwarf2_per_objfile *per_objfile, bfd *abfd,
> >
> > for (formati = 0; formati < format_count; formati++)
> > {
> > - ULONGEST content_type = read_unsigned_leb128 (abfd, format, &bytes_read);
> > + ULONGEST content_type = read_unsigned_leb128 (parent_bfd, format, &bytes_read);
> > format += bytes_read;
> >
> > - ULONGEST form = read_unsigned_leb128 (abfd, format, &bytes_read);
> > + ULONGEST form = read_unsigned_leb128 (parent_bfd, format, &bytes_read);
> > format += bytes_read;
> >
> > gdb::optional<const char *> string;
> > @@ -166,36 +173,48 @@ read_formatted_entries (dwarf2_per_objfile *per_objfile, bfd *abfd,
> > switch (form)
> > {
> > case DW_FORM_string:
> > - string.emplace (read_direct_string (abfd, buf, &bytes_read));
> > + string.emplace (read_direct_string (parent_bfd, buf, &bytes_read));
> > buf += bytes_read;
> > break;
> >
> > case DW_FORM_line_strp:
> > {
> > - const char *str
> > - = per_objfile->read_line_string (buf, offset_size);
> > + if (line_str_data.empty ())
> > + error (_("Dwarf Error: DW_FORM_line_strp used without " \
> > + "required section"));
> > + if (line_str_data.size () <= offset_size)
> > + error (_("Dwarf Error: DW_FORM_line_strp pointing outside " \
> > + "of section .debug_line"));
> > +
> > + ULONGEST str_offset = read_offset (parent_bfd, buf, offset_size);
> > +
> > + const char *str;
> > + if (str_buf[str_offset] == '\0')
> > + str = nullptr;
> > + else
> > + str = (const char *) (str_buf + str_offset);
> > string.emplace (str);
> > buf += offset_size;
> > + break;
> > }
> > - break;
> >
> > case DW_FORM_data1:
> > - uint.emplace (read_1_byte (abfd, buf));
> > + uint.emplace (read_1_byte (parent_bfd, buf));
> > buf += 1;
> > break;
> >
> > case DW_FORM_data2:
> > - uint.emplace (read_2_bytes (abfd, buf));
> > + uint.emplace (read_2_bytes (parent_bfd, buf));
> > buf += 2;
> > break;
> >
> > case DW_FORM_data4:
> > - uint.emplace (read_4_bytes (abfd, buf));
> > + uint.emplace (read_4_bytes (parent_bfd, buf));
> > buf += 4;
> > break;
> >
> > case DW_FORM_data8:
> > - uint.emplace (read_8_bytes (abfd, buf));
> > + uint.emplace (read_8_bytes (parent_bfd, buf));
> > buf += 8;
> > break;
> >
> > @@ -205,7 +224,7 @@ read_formatted_entries (dwarf2_per_objfile *per_objfile, bfd *abfd,
> > break;
> >
> > case DW_FORM_udata:
> > - uint.emplace (read_unsigned_leb128 (abfd, buf, &bytes_read));
> > + uint.emplace (read_unsigned_leb128 (parent_bfd, buf, &bytes_read));
> > buf += bytes_read;
> > break;
> >
> > @@ -244,28 +263,30 @@ read_formatted_entries (dwarf2_per_objfile *per_objfile, bfd *abfd,
> > callback (lh, fe.name, fe.d_index, fe.mod_time, fe.length);
> > }
> >
> > - *bufp = buf;
> > + *line_bufp = buf;
> > }
> >
> > /* See line-header.h. */
> >
> > line_header_up
> > -dwarf_decode_line_header (sect_offset sect_off, bool is_dwz,
> > - dwarf2_per_objfile *per_objfile,
> > - struct dwarf2_section_info *section,
> > - const struct comp_unit_head *cu_header,
> > - const char *comp_dir)
> > +dwarf_decode_line_header (bfd *parent_bfd,
> > + gdb::array_view<const gdb_byte> line_data,
> > + gdb::array_view<const gdb_byte> line_str_data,
> > + const gdb_byte **debug_line_ptr,
> > + bool is_dwz,
> > + const struct comp_unit_head *cu_header,
> > + const char *comp_dir)
> > {
> > - const gdb_byte *line_ptr;
> > + const gdb_byte *line_ptr, *buf;
> > unsigned int bytes_read, offset_size;
> > int i;
> > const char *cur_dir, *cur_file;
> >
> > - bfd *abfd = section->get_bfd_owner ();
> > + buf = *debug_line_ptr;
> >
> > /* Make sure that at least there's room for the total_length field.
> > That could be 12 bytes long, but we're just going to fudge that. */
> > - if (to_underlying (sect_off) + 4 >= section->size)
> > + if (buf + 4 >= line_data.data () + line_data.size ())
> > {
> > dwarf2_statement_list_fits_in_line_number_section_complaint ();
> > return 0;
> > @@ -273,62 +294,65 @@ dwarf_decode_line_header (sect_offset sect_off, bool is_dwz,
> >
> > line_header_up lh (new line_header (comp_dir));
> >
> > - lh->sect_off = sect_off;
> > + lh->sect_off = (sect_offset) (buf - line_data.data ());
> > lh->offset_in_dwz = is_dwz;
> >
> > - line_ptr = section->buffer + to_underlying (sect_off);
> > + line_ptr = buf;
> >
> > /* Read in the header. */
> > LONGEST unit_length
> > - = read_checked_initial_length_and_offset (abfd, line_ptr, cu_header,
> > + = read_checked_initial_length_and_offset (parent_bfd, buf, cu_header,
> > &bytes_read, &offset_size);
> > - line_ptr += bytes_read;
> >
> > - const gdb_byte *start_here = line_ptr;
> > + line_ptr += bytes_read;
> >
> > - if (line_ptr + unit_length > (section->buffer + section->size))
> > + if (line_ptr + unit_length > buf + line_data.size ())
> > {
> > dwarf2_statement_list_fits_in_line_number_section_complaint ();
> > return 0;
> > }
> > +
> > + const gdb_byte *start_here = line_ptr;
> > +
> > lh->statement_program_end = start_here + unit_length;
> > - lh->version = read_2_bytes (abfd, line_ptr);
> > + lh->version = read_2_bytes (parent_bfd, line_ptr);
> > line_ptr += 2;
> > if (lh->version > 5)
> > {
> > /* This is a version we don't understand. The format could have
> > changed in ways we don't handle properly so just punt. */
> > complaint (_("unsupported version in .debug_line section"));
> > - return NULL;
> > + return nullptr;
> > }
> > if (lh->version >= 5)
> > {
> > gdb_byte segment_selector_size;
> >
> > /* Skip address size. */
> > - read_1_byte (abfd, line_ptr);
> > + read_1_byte (parent_bfd, line_ptr);
> > line_ptr += 1;
> >
> > - segment_selector_size = read_1_byte (abfd, line_ptr);
> > + segment_selector_size = read_1_byte (parent_bfd, line_ptr);
> > line_ptr += 1;
> > if (segment_selector_size != 0)
> > {
> > complaint (_("unsupported segment selector size %u "
> > "in .debug_line section"),
> > segment_selector_size);
> > - return NULL;
> > + return nullptr;
> > }
> > }
> >
> > - LONGEST header_length = read_offset (abfd, line_ptr, offset_size);
> > + LONGEST header_length = read_offset (parent_bfd, line_ptr, offset_size);
> > line_ptr += offset_size;
> > lh->statement_program_start = line_ptr + header_length;
> > - lh->minimum_instruction_length = read_1_byte (abfd, line_ptr);
> > +
> > + lh->minimum_instruction_length = read_1_byte (parent_bfd, line_ptr);
> > line_ptr += 1;
> >
> > if (lh->version >= 4)
> > {
> > - lh->maximum_ops_per_instruction = read_1_byte (abfd, line_ptr);
> > + lh->maximum_ops_per_instruction = read_1_byte (parent_bfd, line_ptr);
> > line_ptr += 1;
> > }
> > else
> > @@ -341,41 +365,47 @@ dwarf_decode_line_header (sect_offset sect_off, bool is_dwz,
> > "in `.debug_line' section"));
> > }
> >
> > - lh->default_is_stmt = read_1_byte (abfd, line_ptr);
> > + lh->default_is_stmt = read_1_byte (parent_bfd, line_ptr);
> > line_ptr += 1;
> > - lh->line_base = read_1_signed_byte (abfd, line_ptr);
> > +
> > + lh->line_base = read_1_signed_byte (parent_bfd, line_ptr);
> > line_ptr += 1;
> > - lh->line_range = read_1_byte (abfd, line_ptr);
> > +
> > + lh->line_range = read_1_byte (parent_bfd, line_ptr);
> > line_ptr += 1;
> > - lh->opcode_base = read_1_byte (abfd, line_ptr);
> > +
> > + lh->opcode_base = read_1_byte (parent_bfd, line_ptr);
> > line_ptr += 1;
> > +
> > lh->standard_opcode_lengths.reset (new unsigned char[lh->opcode_base]);
> >
> > lh->standard_opcode_lengths[0] = 1; /* This should never be used anyway. */
> > for (i = 1; i < lh->opcode_base; ++i)
> > {
> > - lh->standard_opcode_lengths[i] = read_1_byte (abfd, line_ptr);
> > + lh->standard_opcode_lengths[i] = read_1_byte (parent_bfd, line_ptr);
> > line_ptr += 1;
> > }
> >
> > if (lh->version >= 5)
> > {
> > /* Read directory table. */
> > - read_formatted_entries (per_objfile, abfd, &line_ptr, lh.get (),
> > - offset_size,
> > - [] (struct line_header *header, const char *name,
> > - dir_index d_index, unsigned int mod_time,
> > - unsigned int length)
> > + read_formatted_entries
> > + (parent_bfd, &line_ptr, line_str_data,
> > + lh.get (), offset_size,
> > + [] (struct line_header *header, const char *name,
> > + dir_index d_index, unsigned int mod_time,
> > + unsigned int length)
> > {
> > header->add_include_dir (name);
> > });
> >
> > /* Read file name table. */
> > - read_formatted_entries (per_objfile, abfd, &line_ptr, lh.get (),
> > - offset_size,
> > - [] (struct line_header *header, const char *name,
> > - dir_index d_index, unsigned int mod_time,
> > - unsigned int length)
> > + read_formatted_entries
> > + (parent_bfd, &line_ptr, line_str_data,
> > + lh.get (), offset_size,
> > + [] (struct line_header *header, const char *name,
> > + dir_index d_index, unsigned int mod_time,
> > + unsigned int length)
> > {
> > header->add_file_name (name, d_index, mod_time, length);
> > });
> > @@ -383,7 +413,7 @@ dwarf_decode_line_header (sect_offset sect_off, bool is_dwz,
> > else
> > {
> > /* Read directory table. */
> > - while ((cur_dir = read_direct_string (abfd, line_ptr, &bytes_read)) != NULL)
> > + while ((cur_dir = read_direct_string (parent_bfd, line_ptr, &bytes_read)) != nullptr)
> > {
> > line_ptr += bytes_read;
> > lh->add_include_dir (cur_dir);
> > @@ -391,17 +421,17 @@ dwarf_decode_line_header (sect_offset sect_off, bool is_dwz,
> > line_ptr += bytes_read;
> >
> > /* Read file name table. */
> > - while ((cur_file = read_direct_string (abfd, line_ptr, &bytes_read)) != NULL)
> > + while ((cur_file = read_direct_string (parent_bfd, line_ptr, &bytes_read)) != nullptr)
> > {
> > unsigned int mod_time, length;
> > dir_index d_index;
> >
> > line_ptr += bytes_read;
> > - d_index = (dir_index) read_unsigned_leb128 (abfd, line_ptr, &bytes_read);
> > + d_index = (dir_index) read_unsigned_leb128 (parent_bfd, line_ptr, &bytes_read);
> > line_ptr += bytes_read;
> > - mod_time = read_unsigned_leb128 (abfd, line_ptr, &bytes_read);
> > + mod_time = read_unsigned_leb128 (parent_bfd, line_ptr, &bytes_read);
> > line_ptr += bytes_read;
> > - length = read_unsigned_leb128 (abfd, line_ptr, &bytes_read);
> > + length = read_unsigned_leb128 (parent_bfd, line_ptr, &bytes_read);
> > line_ptr += bytes_read;
> >
> > lh->add_file_name (cur_file, d_index, mod_time, length);
> > @@ -409,9 +439,40 @@ dwarf_decode_line_header (sect_offset sect_off, bool is_dwz,
> > line_ptr += bytes_read;
> > }
> >
> > - if (line_ptr > (section->buffer + section->size))
> > + if (line_ptr > (buf + line_data.size ()))
> > complaint (_("line number info header doesn't "
> > "fit in `.debug_line' section"));
> >
> > + *debug_line_ptr += unit_length + offset_size;
> > return lh;
> > }
> > +
> > +line_header_up
> > +dwarf_decode_line_header (sect_offset sect_off, bool is_dwz,
> > + dwarf2_per_objfile *per_objfile,
> > + struct dwarf2_section_info *section,
> > + const struct comp_unit_head *cu_header,
> > + const char *comp_dir)
> > +{
> > + struct objfile *objfile = per_objfile->objfile;
> > + struct dwarf2_per_bfd *per_bfd = per_objfile->per_bfd;
> > +
> > + /* Read .debug_line. */
> > + dwarf2_section_info *line_sec = &per_bfd->line;
> > + bfd_size_type line_size = line_sec->get_size (objfile);
> > +
> > + gdb::array_view<const gdb_byte> line (line_sec->buffer, line_size);
> > +
> > + /* Read .debug_line_str. */
> > + dwarf2_section_info *line_str_sec = &per_bfd->line_str;
> > + bfd_size_type line_str_size = line_str_sec->get_size (objfile);
> > +
> > + gdb::array_view<const gdb_byte> line_str (line_str_sec->buffer,
> > + line_str_size);
> > +
> > + const gdb_byte *line_ptr = line.data () + to_underlying (sect_off);
> > +
> > + return dwarf_decode_line_header
> > + (per_bfd->obfd, line, line_str, &line_ptr,
> > + is_dwz, cu_header, comp_dir);
> > +}
> > diff --git a/gdb/dwarf2/line-header.h b/gdb/dwarf2/line-header.h
> > index 59a42e336f5..44e32828ddb 100644
> > --- a/gdb/dwarf2/line-header.h
> > +++ b/gdb/dwarf2/line-header.h
> > @@ -217,4 +217,14 @@ extern line_header_up dwarf_decode_line_header
> > struct dwarf2_section_info *section, const struct comp_unit_head *cu_header,
> > const char *comp_dir);
> >
> > +/* Like above but the .debug_line and .debug_line_str are stored in
> > + LINE_DATA and LINE_STR_DATA. *DEBUG_LINE_PTR should point to a
> > + statement program header within LINE_DATA. */
> > +
> > +extern line_header_up dwarf_decode_line_header
> > + (bfd *parent_bfd, gdb::array_view<const gdb_byte> line_data,
> > + gdb::array_view<const gdb_byte> line_str_data,
> > + const gdb_byte **debug_line_ptr, bool is_dwz,
> > + const comp_unit_head *cu_header, const char *comp_dir);
> > +
> > #endif /* DWARF2_LINE_HEADER_H */
> > diff --git a/gdb/dwarf2/read-gdb-index.c b/gdb/dwarf2/read-gdb-index.c
> > index 895fbede7c2..fe33f23fdfa 100644
> > --- a/gdb/dwarf2/read-gdb-index.c
> > +++ b/gdb/dwarf2/read-gdb-index.c
> > @@ -128,6 +128,9 @@ struct mapped_gdb_index final : public mapped_index_base
> > }
> > };
> >
> > +struct mapped_debug_line;
> > +typedef std::unique_ptr<mapped_debug_line> mapped_debug_line_up;
> > +
> > struct dwarf2_gdb_index : public dwarf2_base_index_functions
> > {
> > /* This dumps minimal information about the index.
> > @@ -179,6 +182,15 @@ struct dwarf2_gdb_index : public dwarf2_base_index_functions
> > /* Calls dwarf2_base_index_functions::find_last_source_symtab and downloads
> > debuginfo if necessary. */
> > struct symtab *find_last_source_symtab (struct objfile *objfile) override;
> > +
> > + /* Filename information related to this .gdb_index. */
> > + mapped_debug_line_up mdl;
> > +
> > + /* Return true if any of the filenames in this .gdb_index's .debug_line
> > + mapping match FILE_MATCHER. Initializes the mapping if necessary. */
> > + bool filename_in_debug_line
> > + (objfile *objfile,
> > + gdb::function_view<expand_symtabs_file_matcher_ftype> file_matcher);
> > };
> >
> > void
> > @@ -588,6 +600,17 @@ dwarf2_gdb_index::do_expand_symtabs_matching
> > return result;
> > }
> >
> > +bool
> > +dwarf2_gdb_index::filename_in_debug_line
> > + (objfile *objfile,
> > + gdb::function_view<expand_symtabs_file_matcher_ftype> file_matcher)
> > +{
> > + if (mdl == nullptr)
> > + mdl.reset (new mapped_debug_line (objfile));
> > +
> > + return mdl->contains_matching_filename (file_matcher);
> > +}
> > +
> > bool
> > dwarf2_gdb_index::expand_symtabs_matching
> > (struct objfile *objfile,
> > @@ -616,6 +639,10 @@ dwarf2_gdb_index::expand_symtabs_matching
> > return false;
> > }
> >
> > + if (file_matcher != nullptr
> > + && !filename_in_debug_line (objfile, file_matcher))
> > + return true;
> > +
> > read_full_dwarf_from_debuginfod (objfile, this);
> > return true;
> > }
> > diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
> > index e561ec035e7..39ee56d7204 100644
> > --- a/gdb/dwarf2/read.c
> > +++ b/gdb/dwarf2/read.c
> > @@ -81,6 +81,7 @@
> > #include "gdbsupport/gdb_optional.h"
> > #include "gdbsupport/underlying.h"
> > #include "gdbsupport/hash_enum.h"
> > +#include "gdbsupport/scoped_mmap.h"
> > #include "filename-seen-cache.h"
> > #include "producer.h"
> > #include <fcntl.h>
> > @@ -2110,6 +2111,170 @@ dw2_get_file_names (dwarf2_per_cu_data *this_cu,
> > return this_cu->file_names;
> > }
> >
> > +#if !HAVE_SYS_MMAN_H
> > +
> > +bool
> > +mapped_debug_line::contains_matching_filename
> > + (gdb::function_view<expand_symtabs_file_matcher_ftype> file_matcher)
> > +{
> > + return false;
> > +}
> > +
> > +gdb::array_view<const gdb_byte>
> > +mapped_debug_line::read_debug_line_separate
> > + (char *filename, std::unique_ptr<index_cache_resource> *resource)
> > +{
> > + return {};
> > +}
> > +
> > +bool
> > +mapped_debug_line::read_debug_line_from_debuginfod (objfile *objfile)
> > +{
> > + return false;
> > +}
> > +
> > +#else /* !HAVE_SYS_MMAN_H */
> > +
> > +struct line_resource_mmap final : public index_cache_resource
> > +{
> > + /* Try to mmap FILENAME. Throw an exception on failure, including if the
> > + file doesn't exist. */
> > + line_resource_mmap (const char *filename)
> > + : mapping (mmap_file (filename))
> > + {}
> > +
> > + scoped_mmap mapping;
> > +};
> > +
> > +/* See read.h. */
> > +
> > +bool
> > +mapped_debug_line::contains_matching_filename
> > + (gdb::function_view<expand_symtabs_file_matcher_ftype> file_matcher)
> > +{
> > + for (line_header_up &lh : line_headers)
> > + for (file_entry &fe : lh->file_names ())
> > + {
> > + const char *filename = fe.name;
> > +
> > + if (file_matcher (fe.name, false))
> > + return true;
> > +
> > + bool basename_match = file_matcher (lbasename (fe.name), true);
> > +
> > + if (!basenames_may_differ && !basename_match)
> > + continue;
> > +
> > + /* DW_AT_comp_dir is not explicitly mentioned in the .debug_line
> > + until DWARF5. Since we don't have access to the CU at this
> > + point we just check for a partial match on the filename.
> > + If there is a match, the full debuginfo will be downloaded
> > + ane the match will be re-evalute with DW_AT_comp_dir. */
> > + if (lh->version < 5 && fe.d_index == 0)
> > + return basename_match;
> > +
> > + const char *dirname = fe.include_dir (&*lh);
> > + std::string fullname;
> > +
> > + if (dirname == nullptr || IS_ABSOLUTE_PATH (filename))
> > + fullname = filename;
> > + else
> > + fullname = std::string (dirname) + SLASH_STRING + filename;
> > +
> > + gdb::unique_xmalloc_ptr<char> rewritten
> > + = rewrite_source_path (fullname.c_str ());
> > + if (rewritten != nullptr)
> > + fullname = rewritten.release ();
> > +
> > + if (file_matcher (fullname.c_str (), false))
> > + return true;
> > + }
> > +
> > + return false;
> > +}
> > +
> > +/* See read.h. */
> > +
> > +gdb::array_view<const gdb_byte>
> > +mapped_debug_line::read_debug_line_separate
> > + (char *filename, std::unique_ptr<index_cache_resource> *resource)
> > +{
> > + if (filename == nullptr)
> > + return {};
> > +
> > + try
> > + {
> > + line_resource_mmap *mmap_resource
> > + = new line_resource_mmap (filename);
> > +
> > + resource->reset (mmap_resource);
> > +
> > + return gdb::array_view<const gdb_byte>
> > + ((const gdb_byte *) mmap_resource->mapping.get (),
> > + mmap_resource->mapping.size ());
> > + }
> > + catch (const gdb_exception &except)
> > + {
> > + exception_print (gdb_stderr, except);
> > + }
> > +
> > + return {};
> > +}
> > +
> > +/* See read.h. */
> > +
> > +bool
> > +mapped_debug_line::read_debug_line_from_debuginfod (objfile *objfile)
> > +{
> > + const bfd_build_id *build_id = build_id_bfd_get (objfile->obfd.get ());
> > + if (build_id == nullptr)
> > + return false;
> > +
> > + gdb::unique_xmalloc_ptr<char> line_path;
> > + scoped_fd line_fd = debuginfod_section_query (build_id->data,
> > + build_id->size,
> > + bfd_get_filename
> > + (objfile->obfd.get ()),
> > + ".debug_line",
> > + &line_path);
> > +
> > + if (line_fd.get () < 0)
> > + return false;
> > +
> > + gdb::unique_xmalloc_ptr<char> line_str_path;
> > + scoped_fd line_str_fd = debuginfod_section_query (build_id->data,
> > + build_id->size,
> > + bfd_get_filename
> > + (objfile->obfd.get ()),
> > + ".debug_line_str",
> > + &line_str_path);
> > +
> > + line_data = read_debug_line_separate (line_path.get (), &line_resource);
> > + line_str_data = read_debug_line_separate (line_str_path.get (),
> > + &line_str_resource);
> > +
> > + const gdb_byte *line_ptr = line_data.data ();
> > +
> > + while (line_ptr < line_data.data () + line_data.size ())
> > + {
> > + line_header_up lh
> > + = dwarf_decode_line_header (objfile->obfd.get (),
> > + line_data, line_str_data,
> > + &line_ptr, false,
> > + nullptr, nullptr);
> > + line_headers.emplace_back (lh.release ());
> > + }
> > +
> > + return true;
> > +}
> > +#endif /* !HAVE_SYS_MMAN_H */
> > +
> > +mapped_debug_line::mapped_debug_line (objfile *objfile)
> > +{
> > + if (!read_debug_line_from_debuginfod (objfile))
> > + line_headers.clear ();
> > +}
> > +
> > /* A helper for the "quick" functions which computes and caches the
> > real path for a given file name from the line table. */
> >
> > diff --git a/gdb/dwarf2/read.h b/gdb/dwarf2/read.h
> > index e3131693b81..b8a8b76bde0 100644
> > --- a/gdb/dwarf2/read.h
> > +++ b/gdb/dwarf2/read.h
> > @@ -34,6 +34,7 @@
> > #include "gdbsupport/hash_enum.h"
> > #include "gdbsupport/function-view.h"
> > #include "gdbsupport/packed.h"
> > +#include "dwarf2/line-header.h"
> >
> > /* Hold 'maintenance (set|show) dwarf' commands. */
> > extern struct cmd_list_element *set_dwarf_cmdlist;
> > @@ -952,4 +953,34 @@ extern bool read_addrmap_from_aranges (dwarf2_per_objfile *per_objfile,
> > extern void read_full_dwarf_from_debuginfod (struct objfile *,
> > dwarf2_base_index_functions *);
> >
> > +struct mapped_debug_line
> > +{
> > + mapped_debug_line (objfile *objfile);
> > +
> > + /* Return true if any of the mapped .debug_line's filenames match
> > + FILE_MATCHER. */
> > +
> > + bool contains_matching_filename
> > + (gdb::function_view<expand_symtabs_file_matcher_ftype> file_matcher);
> > +
> > +private:
> > + std::vector<line_header_up> line_headers;
> > +
> > + gdb::array_view<const gdb_byte> line_data;
> > + gdb::array_view<const gdb_byte> line_str_data;
> > +
> > + std::unique_ptr<index_cache_resource> line_resource;
> > + std::unique_ptr<index_cache_resource> line_str_resource;
> > +
> > + /* Download the .debug_line and .debug_line_str associated with OBJFILE
> > + and populate line_headers. */
> > +
> > + bool read_debug_line_from_debuginfod (objfile *objfile);
> > +
> > + /* Initialize line_data and line_str_data with the .debug_line and
> > + .debug_line_str downloaded read_debug_line_from_debuginfod. */
> > +
> > + gdb::array_view<const gdb_byte> read_debug_line_separate
> > + (char *filename, std::unique_ptr<index_cache_resource> *resource);
> > +};
> > #endif /* DWARF2READ_H */
> > --
> > 2.39.2
> >
next prev parent reply other threads:[~2023-05-09 13:50 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-17 18:07 [PATCH " Aaron Merey
2023-05-02 14:25 ` Aaron Merey
2023-05-09 13:49 ` Aaron Merey [this message]
2023-05-16 14:50 ` [PING*3][PATCH " Aaron Merey
2023-05-23 20:55 ` [PING*4][PATCH " Aaron Merey
2023-05-24 10:22 ` [PATCH " Andrew Burgess
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