This patch avoids depending on the current locale when parsing &
comparing symbol names, by using libiberty's safe-ctype.h uppercase
TOLOWER, ISXDIGIT, etc. macros instead of the standard ctype.h
tolower, isxdigit, etc. macros/functions.
This commit:
commit b1b60145ae
Author: Pedro Alves <palves@redhat.com>
AuthorDate: Tue May 22 17:35:38 2018 +0100
Support UTF-8 identifiers in C/C++ expressions (PR gdb/22973)
did something similar, except in the expression parser.
This can improve GDB's symbol loading performance significantly.
Currently strcmp_iw_ordered can show up high on profiles (called from
sort_pst_symbols -> std::sort) because of the isspace and tolower
functions. Hannes mentions seeing it as high as in ~24% of the
profiling samples on Windows
(https://sourceware.org/pipermail/gdb-patches/2020-May/168858.html).
I tested GDB's performance (built with "-g -O2") loading a "-g -O0"
build of gdb.
I ran GDB 10 times like:
/bin/time -f %e \
./gdb/gdb --data-directory ./gdb/data-directory -nx \
-batch /tmp/gdb-g-O0
Then I computed the mean time.
The baseline mean time was
gdb 2.515
This patch brings the number down to
gdb 2.096
Which is an around 16% improvement.
gdb/ChangeLog:
2020-05-23 Pedro Alves <palves@redhat.com>
* utils.c: Include "gdbsupport/gdb-safe-ctype.h".
(parse_escape): Use ISDIGIT instead of isdigit.
(puts_debug): Use gdb_isprint instead of isprint.
(fprintf_symbol_filtered): Use ISALNUM instead of isalnum.
(cp_skip_operator_token, skip_ws, strncmp_iw_with_mode): Use
ISSPACE instead of isspace.
(strncmp_iw_with_mode): Use TOLOWER instead of tolower and ISSPACE
instead of isspace.
(strcmp_iw_ordered): Use ISSPACE instead of isspace.
(string_to_core_addr): Use TOLOWER instead of tolower, ISXDIGIT
instead of isxdigit and ISDIGIT instead of isdigit.
gdbsupport/ChangeLog:
2020-05-23 Pedro Alves <palves@redhat.com>
* gdb-safe-ctype.h: New.
This is a helper library that is used by gdb and gdbserver.
To send patches, follow the gdb patch submission instructions in
../gdb/CONTRIBUTE. For maintainers, see ../gdb/MAINTAINERS.
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