From 049522cae9798e51dd0c58566a9a2c61ba9100a9 Mon Sep 17 00:00:00 2001 From: Michael Matz Date: Tue, 22 Nov 2022 15:24:14 +0100 Subject: [PATCH] Special case more simple patterns fnmatch is slow, so avoiding it in more cases is good. This implements a more generic version of match_simple_wild which needs some pre-processing of patterns. In particular it supports patterns of the form PREFIX*SUFFIX (where all parts are optional), i.e. a super set of what's handled now. Most section matchers of this form and hence don't need any calls to fnmatch anymore. We retain the implementation of match_simple_wild for the filename matchers (they aren't called often enough to matter). --- ld/ld.h | 3 +- ld/ldlang.c | 125 ++++++++++++++++++++++++++++++++++++++-------------- 2 files changed, 95 insertions(+), 33 deletions(-) diff --git a/ld/ld.h b/ld/ld.h index 2ac9f469d04..2a95e14e3b8 100644 --- a/ld/ld.h +++ b/ld/ld.h @@ -98,8 +98,9 @@ struct wildcard_spec { const char *name; struct name_list *exclude_name_list; - sort_type sorted; struct flag_info *section_flag_list; + size_t namelen, prefixlen, suffixlen; + sort_type sorted; }; struct wildcard_list diff --git a/ld/ldlang.c b/ld/ldlang.c index 03daba6ef7f..5fc55dcd5dd 100644 --- a/ld/ldlang.c +++ b/ld/ldlang.c @@ -169,14 +169,75 @@ stat_alloc (size_t size) return obstack_alloc (&stat_obstack, size); } +/* Code for handling simple wildcards without going through fnmatch, + which can be expensive because of charset translations etc. */ + +/* A simple wild is a literal string followed by a single '*', + where the literal part is at least 4 characters long. */ + +static bool +is_simple_wild (const char *name) +{ + size_t len = strcspn (name, "*?["); + return len >= 4 && name[len] == '*' && name[len + 1] == '\0'; +} + +static bool +match_simple_wild (const char *pattern, const char *name) +{ + /* The first four characters of the pattern are guaranteed valid + non-wildcard characters. So we can go faster. */ + if (pattern[0] != name[0] || pattern[1] != name[1] + || pattern[2] != name[2] || pattern[3] != name[3]) + return false; + + pattern += 4; + name += 4; + while (*pattern != '*') + if (*name++ != *pattern++) + return false; + + return true; +} + static int name_match (const char *pattern, const char *name) { + if (is_simple_wild (pattern)) + return !match_simple_wild (pattern, name); if (wildcardp (pattern)) return fnmatch (pattern, name, 0); return strcmp (pattern, name); } +/* Given an analyzed wildcard_spec SPEC, match it against NAME, + returns zero on a match, non-zero if there's no match. */ + +static int +spec_match (const struct wildcard_spec *spec, const char *name) +{ + size_t nl = spec->namelen; + size_t pl = spec->prefixlen; + size_t sl = spec->suffixlen; + int r; + if (pl && (r = memcmp (spec->name, name, pl))) + return r; + if (sl) + { + size_t inputlen = strlen (name); + if (inputlen < sl) + return 1; + r = memcmp (spec->name + nl - sl, name + inputlen - sl, sl); + if (r) + return r; + } + if (nl == pl + sl + 1 && spec->name[pl] == '*') + return 0; + else if (nl > pl) + return fnmatch (spec->name + pl, name + pl, 0); + return name[nl]; +} + static char * ldirname (const char *name) { @@ -349,7 +410,7 @@ walk_wild_section_general (lang_wild_statement_type *ptr, { const char *sname = bfd_section_name (s); - skip = name_match (sec->spec.name, sname) != 0; + skip = spec_match (&sec->spec, sname) != 0; } if (!skip) @@ -397,37 +458,6 @@ find_section (lang_input_statement_type *file, return cb_data.found_section; } -/* Code for handling simple wildcards without going through fnmatch, - which can be expensive because of charset translations etc. */ - -/* A simple wild is a literal string followed by a single '*', - where the literal part is at least 4 characters long. */ - -static bool -is_simple_wild (const char *name) -{ - size_t len = strcspn (name, "*?["); - return len >= 4 && name[len] == '*' && name[len + 1] == '\0'; -} - -static bool -match_simple_wild (const char *pattern, const char *name) -{ - /* The first four characters of the pattern are guaranteed valid - non-wildcard characters. So we can go faster. */ - if (pattern[0] != name[0] || pattern[1] != name[1] - || pattern[2] != name[2] || pattern[3] != name[3]) - return false; - - pattern += 4; - name += 4; - while (*pattern != '*') - if (*name++ != *pattern++) - return false; - - return true; -} - /* Return the numerical value of the init_priority attribute from section name NAME. */ @@ -821,6 +851,24 @@ wild_spec_can_overlap (const char *name1, const char *name2) return memcmp (name1, name2, min_prefix_len) == 0; } +/* Like strcspn() but start to look from the end to beginning of + S. Returns the length of the suffix of S consisting entirely + of characters not in REJECT. */ + +static size_t +rstrcspn (const char *s, const char *reject) +{ + size_t len = strlen (s), sufflen = 0; + while (len--) + { + char c = s[len]; + if (strchr (reject, c) != 0) + break; + sufflen++; + } + return sufflen; +} + /* Select specialized code to handle various kinds of wildcard statements. */ @@ -840,6 +888,19 @@ analyze_walk_wild_section_handler (lang_wild_statement_type *ptr) ptr->handler_data[3] = NULL; ptr->tree = NULL; + for (sec = ptr->section_list; sec != NULL; sec = sec->next) + { + if (sec->spec.name) + { + sec->spec.namelen = strlen (sec->spec.name); + sec->spec.prefixlen = strcspn (sec->spec.name, "?*["); + sec->spec.suffixlen = rstrcspn (sec->spec.name + sec->spec.prefixlen, + "?*]"); + } + else + sec->spec.namelen = sec->spec.prefixlen = sec->spec.suffixlen = 0; + } + /* Count how many wildcard_specs there are, and how many of those actually use wildcards in the name. Also, bail out if any of the wildcard names are NULL. (Can this actually happen? -- 2.30.2