Root/tools/perf/util/config.c

1/*
2 * GIT - The information manager from hell
3 *
4 * Copyright (C) Linus Torvalds, 2005
5 * Copyright (C) Johannes Schindelin, 2005
6 *
7 */
8#include "util.h"
9#include "cache.h"
10#include "exec_cmd.h"
11
12#define MAXNAME (256)
13
14static FILE *config_file;
15static const char *config_file_name;
16static int config_linenr;
17static int config_file_eof;
18
19const char *config_exclusive_filename = NULL;
20
21static int get_next_char(void)
22{
23    int c;
24    FILE *f;
25
26    c = '\n';
27    if ((f = config_file) != NULL) {
28        c = fgetc(f);
29        if (c == '\r') {
30            /* DOS like systems */
31            c = fgetc(f);
32            if (c != '\n') {
33                ungetc(c, f);
34                c = '\r';
35            }
36        }
37        if (c == '\n')
38            config_linenr++;
39        if (c == EOF) {
40            config_file_eof = 1;
41            c = '\n';
42        }
43    }
44    return c;
45}
46
47static char *parse_value(void)
48{
49    static char value[1024];
50    int quote = 0, comment = 0, space = 0;
51    size_t len = 0;
52
53    for (;;) {
54        int c = get_next_char();
55
56        if (len >= sizeof(value) - 1)
57            return NULL;
58        if (c == '\n') {
59            if (quote)
60                return NULL;
61            value[len] = 0;
62            return value;
63        }
64        if (comment)
65            continue;
66        if (isspace(c) && !quote) {
67            space = 1;
68            continue;
69        }
70        if (!quote) {
71            if (c == ';' || c == '#') {
72                comment = 1;
73                continue;
74            }
75        }
76        if (space) {
77            if (len)
78                value[len++] = ' ';
79            space = 0;
80        }
81        if (c == '\\') {
82            c = get_next_char();
83            switch (c) {
84            case '\n':
85                continue;
86            case 't':
87                c = '\t';
88                break;
89            case 'b':
90                c = '\b';
91                break;
92            case 'n':
93                c = '\n';
94                break;
95            /* Some characters escape as themselves */
96            case '\\': case '"':
97                break;
98            /* Reject unknown escape sequences */
99            default:
100                return NULL;
101            }
102            value[len++] = c;
103            continue;
104        }
105        if (c == '"') {
106            quote = 1-quote;
107            continue;
108        }
109        value[len++] = c;
110    }
111}
112
113static inline int iskeychar(int c)
114{
115    return isalnum(c) || c == '-';
116}
117
118static int get_value(config_fn_t fn, void *data, char *name, unsigned int len)
119{
120    int c;
121    char *value;
122
123    /* Get the full name */
124    for (;;) {
125        c = get_next_char();
126        if (config_file_eof)
127            break;
128        if (!iskeychar(c))
129            break;
130        name[len++] = tolower(c);
131        if (len >= MAXNAME)
132            return -1;
133    }
134    name[len] = 0;
135    while (c == ' ' || c == '\t')
136        c = get_next_char();
137
138    value = NULL;
139    if (c != '\n') {
140        if (c != '=')
141            return -1;
142        value = parse_value();
143        if (!value)
144            return -1;
145    }
146    return fn(name, value, data);
147}
148
149static int get_extended_base_var(char *name, int baselen, int c)
150{
151    do {
152        if (c == '\n')
153            return -1;
154        c = get_next_char();
155    } while (isspace(c));
156
157    /* We require the format to be '[base "extension"]' */
158    if (c != '"')
159        return -1;
160    name[baselen++] = '.';
161
162    for (;;) {
163        int ch = get_next_char();
164
165        if (ch == '\n')
166            return -1;
167        if (ch == '"')
168            break;
169        if (ch == '\\') {
170            ch = get_next_char();
171            if (ch == '\n')
172                return -1;
173        }
174        name[baselen++] = ch;
175        if (baselen > MAXNAME / 2)
176            return -1;
177    }
178
179    /* Final ']' */
180    if (get_next_char() != ']')
181        return -1;
182    return baselen;
183}
184
185static int get_base_var(char *name)
186{
187    int baselen = 0;
188
189    for (;;) {
190        int c = get_next_char();
191        if (config_file_eof)
192            return -1;
193        if (c == ']')
194            return baselen;
195        if (isspace(c))
196            return get_extended_base_var(name, baselen, c);
197        if (!iskeychar(c) && c != '.')
198            return -1;
199        if (baselen > MAXNAME / 2)
200            return -1;
201        name[baselen++] = tolower(c);
202    }
203}
204
205static int perf_parse_file(config_fn_t fn, void *data)
206{
207    int comment = 0;
208    int baselen = 0;
209    static char var[MAXNAME];
210
211    /* U+FEFF Byte Order Mark in UTF8 */
212    static const unsigned char *utf8_bom = (unsigned char *) "\xef\xbb\xbf";
213    const unsigned char *bomptr = utf8_bom;
214
215    for (;;) {
216        int c = get_next_char();
217        if (bomptr && *bomptr) {
218            /* We are at the file beginning; skip UTF8-encoded BOM
219             * if present. Sane editors won't put this in on their
220             * own, but e.g. Windows Notepad will do it happily. */
221            if ((unsigned char) c == *bomptr) {
222                bomptr++;
223                continue;
224            } else {
225                /* Do not tolerate partial BOM. */
226                if (bomptr != utf8_bom)
227                    break;
228                /* No BOM at file beginning. Cool. */
229                bomptr = NULL;
230            }
231        }
232        if (c == '\n') {
233            if (config_file_eof)
234                return 0;
235            comment = 0;
236            continue;
237        }
238        if (comment || isspace(c))
239            continue;
240        if (c == '#' || c == ';') {
241            comment = 1;
242            continue;
243        }
244        if (c == '[') {
245            baselen = get_base_var(var);
246            if (baselen <= 0)
247                break;
248            var[baselen++] = '.';
249            var[baselen] = 0;
250            continue;
251        }
252        if (!isalpha(c))
253            break;
254        var[baselen] = tolower(c);
255        if (get_value(fn, data, var, baselen+1) < 0)
256            break;
257    }
258    die("bad config file line %d in %s", config_linenr, config_file_name);
259}
260
261static int parse_unit_factor(const char *end, unsigned long *val)
262{
263    if (!*end)
264        return 1;
265    else if (!strcasecmp(end, "k")) {
266        *val *= 1024;
267        return 1;
268    }
269    else if (!strcasecmp(end, "m")) {
270        *val *= 1024 * 1024;
271        return 1;
272    }
273    else if (!strcasecmp(end, "g")) {
274        *val *= 1024 * 1024 * 1024;
275        return 1;
276    }
277    return 0;
278}
279
280static int perf_parse_long(const char *value, long *ret)
281{
282    if (value && *value) {
283        char *end;
284        long val = strtol(value, &end, 0);
285        unsigned long factor = 1;
286        if (!parse_unit_factor(end, &factor))
287            return 0;
288        *ret = val * factor;
289        return 1;
290    }
291    return 0;
292}
293
294int perf_parse_ulong(const char *value, unsigned long *ret)
295{
296    if (value && *value) {
297        char *end;
298        unsigned long val = strtoul(value, &end, 0);
299        if (!parse_unit_factor(end, &val))
300            return 0;
301        *ret = val;
302        return 1;
303    }
304    return 0;
305}
306
307static void die_bad_config(const char *name)
308{
309    if (config_file_name)
310        die("bad config value for '%s' in %s", name, config_file_name);
311    die("bad config value for '%s'", name);
312}
313
314int perf_config_int(const char *name, const char *value)
315{
316    long ret = 0;
317    if (!perf_parse_long(value, &ret))
318        die_bad_config(name);
319    return ret;
320}
321
322unsigned long perf_config_ulong(const char *name, const char *value)
323{
324    unsigned long ret;
325    if (!perf_parse_ulong(value, &ret))
326        die_bad_config(name);
327    return ret;
328}
329
330int perf_config_bool_or_int(const char *name, const char *value, int *is_bool)
331{
332    *is_bool = 1;
333    if (!value)
334        return 1;
335    if (!*value)
336        return 0;
337    if (!strcasecmp(value, "true") || !strcasecmp(value, "yes") || !strcasecmp(value, "on"))
338        return 1;
339    if (!strcasecmp(value, "false") || !strcasecmp(value, "no") || !strcasecmp(value, "off"))
340        return 0;
341    *is_bool = 0;
342    return perf_config_int(name, value);
343}
344
345int perf_config_bool(const char *name, const char *value)
346{
347    int discard;
348    return !!perf_config_bool_or_int(name, value, &discard);
349}
350
351int perf_config_string(const char **dest, const char *var, const char *value)
352{
353    if (!value)
354        return config_error_nonbool(var);
355    *dest = strdup(value);
356    return 0;
357}
358
359static int perf_default_core_config(const char *var __used, const char *value __used)
360{
361    /* Add other config variables here and to Documentation/config.txt. */
362    return 0;
363}
364
365int perf_default_config(const char *var, const char *value, void *dummy __used)
366{
367    if (!prefixcmp(var, "core."))
368        return perf_default_core_config(var, value);
369
370    /* Add other config variables here and to Documentation/config.txt. */
371    return 0;
372}
373
374int perf_config_from_file(config_fn_t fn, const char *filename, void *data)
375{
376    int ret;
377    FILE *f = fopen(filename, "r");
378
379    ret = -1;
380    if (f) {
381        config_file = f;
382        config_file_name = filename;
383        config_linenr = 1;
384        config_file_eof = 0;
385        ret = perf_parse_file(fn, data);
386        fclose(f);
387        config_file_name = NULL;
388    }
389    return ret;
390}
391
392const char *perf_etc_perfconfig(void)
393{
394    static const char *system_wide;
395    if (!system_wide)
396        system_wide = system_path(ETC_PERFCONFIG);
397    return system_wide;
398}
399
400static int perf_env_bool(const char *k, int def)
401{
402    const char *v = getenv(k);
403    return v ? perf_config_bool(k, v) : def;
404}
405
406int perf_config_system(void)
407{
408    return !perf_env_bool("PERF_CONFIG_NOSYSTEM", 0);
409}
410
411int perf_config_global(void)
412{
413    return !perf_env_bool("PERF_CONFIG_NOGLOBAL", 0);
414}
415
416int perf_config(config_fn_t fn, void *data)
417{
418    int ret = 0, found = 0;
419    char *repo_config = NULL;
420    const char *home = NULL;
421
422    /* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
423    if (config_exclusive_filename)
424        return perf_config_from_file(fn, config_exclusive_filename, data);
425    if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) {
426        ret += perf_config_from_file(fn, perf_etc_perfconfig(),
427                        data);
428        found += 1;
429    }
430
431    home = getenv("HOME");
432    if (perf_config_global() && home) {
433        char *user_config = strdup(mkpath("%s/.perfconfig", home));
434        if (!access(user_config, R_OK)) {
435            ret += perf_config_from_file(fn, user_config, data);
436            found += 1;
437        }
438        free(user_config);
439    }
440
441    repo_config = perf_pathdup("config");
442    if (!access(repo_config, R_OK)) {
443        ret += perf_config_from_file(fn, repo_config, data);
444        found += 1;
445    }
446    free(repo_config);
447    if (found == 0)
448        return -1;
449    return ret;
450}
451
452/*
453 * Find all the stuff for perf_config_set() below.
454 */
455
456#define MAX_MATCHES 512
457
458static struct {
459    int baselen;
460    char* key;
461    int do_not_match;
462    regex_t* value_regex;
463    int multi_replace;
464    size_t offset[MAX_MATCHES];
465    enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
466    int seen;
467} store;
468
469static int matches(const char* key, const char* value)
470{
471    return !strcmp(key, store.key) &&
472        (store.value_regex == NULL ||
473         (store.do_not_match ^
474          !regexec(store.value_regex, value, 0, NULL, 0)));
475}
476
477static int store_aux(const char* key, const char* value, void *cb __used)
478{
479    int section_len;
480    const char *ep;
481
482    switch (store.state) {
483    case KEY_SEEN:
484        if (matches(key, value)) {
485            if (store.seen == 1 && store.multi_replace == 0) {
486                warning("%s has multiple values", key);
487            } else if (store.seen >= MAX_MATCHES) {
488                error("too many matches for %s", key);
489                return 1;
490            }
491
492            store.offset[store.seen] = ftell(config_file);
493            store.seen++;
494        }
495        break;
496    case SECTION_SEEN:
497        /*
498         * What we are looking for is in store.key (both
499         * section and var), and its section part is baselen
500         * long. We found key (again, both section and var).
501         * We would want to know if this key is in the same
502         * section as what we are looking for. We already
503         * know we are in the same section as what should
504         * hold store.key.
505         */
506        ep = strrchr(key, '.');
507        section_len = ep - key;
508
509        if ((section_len != store.baselen) ||
510            memcmp(key, store.key, section_len+1)) {
511            store.state = SECTION_END_SEEN;
512            break;
513        }
514
515        /*
516         * Do not increment matches: this is no match, but we
517         * just made sure we are in the desired section.
518         */
519        store.offset[store.seen] = ftell(config_file);
520        /* fallthru */
521    case SECTION_END_SEEN:
522    case START:
523        if (matches(key, value)) {
524            store.offset[store.seen] = ftell(config_file);
525            store.state = KEY_SEEN;
526            store.seen++;
527        } else {
528            if (strrchr(key, '.') - key == store.baselen &&
529                  !strncmp(key, store.key, store.baselen)) {
530                    store.state = SECTION_SEEN;
531                    store.offset[store.seen] = ftell(config_file);
532            }
533        }
534    default:
535        break;
536    }
537    return 0;
538}
539
540static int store_write_section(int fd, const char* key)
541{
542    const char *dot;
543    int i, success;
544    struct strbuf sb = STRBUF_INIT;
545
546    dot = memchr(key, '.', store.baselen);
547    if (dot) {
548        strbuf_addf(&sb, "[%.*s \"", (int)(dot - key), key);
549        for (i = dot - key + 1; i < store.baselen; i++) {
550            if (key[i] == '"' || key[i] == '\\')
551                strbuf_addch(&sb, '\\');
552            strbuf_addch(&sb, key[i]);
553        }
554        strbuf_addstr(&sb, "\"]\n");
555    } else {
556        strbuf_addf(&sb, "[%.*s]\n", store.baselen, key);
557    }
558
559    success = (write_in_full(fd, sb.buf, sb.len) == (ssize_t)sb.len);
560    strbuf_release(&sb);
561
562    return success;
563}
564
565static int store_write_pair(int fd, const char* key, const char* value)
566{
567    int i, success;
568    int length = strlen(key + store.baselen + 1);
569    const char *quote = "";
570    struct strbuf sb = STRBUF_INIT;
571
572    /*
573     * Check to see if the value needs to be surrounded with a dq pair.
574     * Note that problematic characters are always backslash-quoted; this
575     * check is about not losing leading or trailing SP and strings that
576     * follow beginning-of-comment characters (i.e. ';' and '#') by the
577     * configuration parser.
578     */
579    if (value[0] == ' ')
580        quote = "\"";
581    for (i = 0; value[i]; i++)
582        if (value[i] == ';' || value[i] == '#')
583            quote = "\"";
584    if (i && value[i - 1] == ' ')
585        quote = "\"";
586
587    strbuf_addf(&sb, "\t%.*s = %s",
588            length, key + store.baselen + 1, quote);
589
590    for (i = 0; value[i]; i++)
591        switch (value[i]) {
592        case '\n':
593            strbuf_addstr(&sb, "\\n");
594            break;
595        case '\t':
596            strbuf_addstr(&sb, "\\t");
597            break;
598        case '"':
599        case '\\':
600            strbuf_addch(&sb, '\\');
601        default:
602            strbuf_addch(&sb, value[i]);
603            break;
604        }
605    strbuf_addf(&sb, "%s\n", quote);
606
607    success = (write_in_full(fd, sb.buf, sb.len) == (ssize_t)sb.len);
608    strbuf_release(&sb);
609
610    return success;
611}
612
613static ssize_t find_beginning_of_line(const char* contents, size_t size,
614    size_t offset_, int* found_bracket)
615{
616    size_t equal_offset = size, bracket_offset = size;
617    ssize_t offset;
618
619contline:
620    for (offset = offset_-2; offset > 0
621            && contents[offset] != '\n'; offset--)
622        switch (contents[offset]) {
623            case '=': equal_offset = offset; break;
624            case ']': bracket_offset = offset; break;
625            default: break;
626        }
627    if (offset > 0 && contents[offset-1] == '\\') {
628        offset_ = offset;
629        goto contline;
630    }
631    if (bracket_offset < equal_offset) {
632        *found_bracket = 1;
633        offset = bracket_offset+1;
634    } else
635        offset++;
636
637    return offset;
638}
639
640int perf_config_set(const char* key, const char* value)
641{
642    return perf_config_set_multivar(key, value, NULL, 0);
643}
644
645/*
646 * If value==NULL, unset in (remove from) config,
647 * if value_regex!=NULL, disregard key/value pairs where value does not match.
648 * if multi_replace==0, nothing, or only one matching key/value is replaced,
649 * else all matching key/values (regardless how many) are removed,
650 * before the new pair is written.
651 *
652 * Returns 0 on success.
653 *
654 * This function does this:
655 *
656 * - it locks the config file by creating ".perf/config.lock"
657 *
658 * - it then parses the config using store_aux() as validator to find
659 * the position on the key/value pair to replace. If it is to be unset,
660 * it must be found exactly once.
661 *
662 * - the config file is mmap()ed and the part before the match (if any) is
663 * written to the lock file, then the changed part and the rest.
664 *
665 * - the config file is removed and the lock file rename()d to it.
666 *
667 */
668int perf_config_set_multivar(const char* key, const char* value,
669    const char* value_regex, int multi_replace)
670{
671    int i, dot;
672    int fd = -1, in_fd;
673    int ret = 0;
674    char* config_filename;
675    const char* last_dot = strrchr(key, '.');
676
677    if (config_exclusive_filename)
678        config_filename = strdup(config_exclusive_filename);
679    else
680        config_filename = perf_pathdup("config");
681
682    /*
683     * Since "key" actually contains the section name and the real
684     * key name separated by a dot, we have to know where the dot is.
685     */
686
687    if (last_dot == NULL) {
688        error("key does not contain a section: %s", key);
689        ret = 2;
690        goto out_free;
691    }
692    store.baselen = last_dot - key;
693
694    store.multi_replace = multi_replace;
695
696    /*
697     * Validate the key and while at it, lower case it for matching.
698     */
699    store.key = malloc(strlen(key) + 1);
700    dot = 0;
701    for (i = 0; key[i]; i++) {
702        unsigned char c = key[i];
703        if (c == '.')
704            dot = 1;
705        /* Leave the extended basename untouched.. */
706        if (!dot || i > store.baselen) {
707            if (!iskeychar(c) || (i == store.baselen+1 && !isalpha(c))) {
708                error("invalid key: %s", key);
709                free(store.key);
710                ret = 1;
711                goto out_free;
712            }
713            c = tolower(c);
714        } else if (c == '\n') {
715            error("invalid key (newline): %s", key);
716            free(store.key);
717            ret = 1;
718            goto out_free;
719        }
720        store.key[i] = c;
721    }
722    store.key[i] = 0;
723
724    /*
725     * If .perf/config does not exist yet, write a minimal version.
726     */
727    in_fd = open(config_filename, O_RDONLY);
728    if ( in_fd < 0 ) {
729        free(store.key);
730
731        if ( ENOENT != errno ) {
732            error("opening %s: %s", config_filename,
733                  strerror(errno));
734            ret = 3; /* same as "invalid config file" */
735            goto out_free;
736        }
737        /* if nothing to unset, error out */
738        if (value == NULL) {
739            ret = 5;
740            goto out_free;
741        }
742
743        store.key = (char*)key;
744        if (!store_write_section(fd, key) ||
745            !store_write_pair(fd, key, value))
746            goto write_err_out;
747    } else {
748        struct stat st;
749        char *contents;
750        ssize_t contents_sz, copy_begin, copy_end;
751        int new_line = 0;
752
753        if (value_regex == NULL)
754            store.value_regex = NULL;
755        else {
756            if (value_regex[0] == '!') {
757                store.do_not_match = 1;
758                value_regex++;
759            } else
760                store.do_not_match = 0;
761
762            store.value_regex = (regex_t*)malloc(sizeof(regex_t));
763            if (regcomp(store.value_regex, value_regex,
764                    REG_EXTENDED)) {
765                error("invalid pattern: %s", value_regex);
766                free(store.value_regex);
767                ret = 6;
768                goto out_free;
769            }
770        }
771
772        store.offset[0] = 0;
773        store.state = START;
774        store.seen = 0;
775
776        /*
777         * After this, store.offset will contain the *end* offset
778         * of the last match, or remain at 0 if no match was found.
779         * As a side effect, we make sure to transform only a valid
780         * existing config file.
781         */
782        if (perf_config_from_file(store_aux, config_filename, NULL)) {
783            error("invalid config file %s", config_filename);
784            free(store.key);
785            if (store.value_regex != NULL) {
786                regfree(store.value_regex);
787                free(store.value_regex);
788            }
789            ret = 3;
790            goto out_free;
791        }
792
793        free(store.key);
794        if (store.value_regex != NULL) {
795            regfree(store.value_regex);
796            free(store.value_regex);
797        }
798
799        /* if nothing to unset, or too many matches, error out */
800        if ((store.seen == 0 && value == NULL) ||
801                (store.seen > 1 && multi_replace == 0)) {
802            ret = 5;
803            goto out_free;
804        }
805
806        fstat(in_fd, &st);
807        contents_sz = xsize_t(st.st_size);
808        contents = mmap(NULL, contents_sz, PROT_READ,
809            MAP_PRIVATE, in_fd, 0);
810        close(in_fd);
811
812        if (store.seen == 0)
813            store.seen = 1;
814
815        for (i = 0, copy_begin = 0; i < store.seen; i++) {
816            if (store.offset[i] == 0) {
817                store.offset[i] = copy_end = contents_sz;
818            } else if (store.state != KEY_SEEN) {
819                copy_end = store.offset[i];
820            } else
821                copy_end = find_beginning_of_line(
822                    contents, contents_sz,
823                    store.offset[i]-2, &new_line);
824
825            if (copy_end > 0 && contents[copy_end-1] != '\n')
826                new_line = 1;
827
828            /* write the first part of the config */
829            if (copy_end > copy_begin) {
830                if (write_in_full(fd, contents + copy_begin,
831                          copy_end - copy_begin) <
832                    copy_end - copy_begin)
833                    goto write_err_out;
834                if (new_line &&
835                    write_in_full(fd, "\n", 1) != 1)
836                    goto write_err_out;
837            }
838            copy_begin = store.offset[i];
839        }
840
841        /* write the pair (value == NULL means unset) */
842        if (value != NULL) {
843            if (store.state == START) {
844                if (!store_write_section(fd, key))
845                    goto write_err_out;
846            }
847            if (!store_write_pair(fd, key, value))
848                goto write_err_out;
849        }
850
851        /* write the rest of the config */
852        if (copy_begin < contents_sz)
853            if (write_in_full(fd, contents + copy_begin,
854                      contents_sz - copy_begin) <
855                contents_sz - copy_begin)
856                goto write_err_out;
857
858        munmap(contents, contents_sz);
859    }
860
861    ret = 0;
862
863out_free:
864    free(config_filename);
865    return ret;
866
867write_err_out:
868    goto out_free;
869
870}
871
872/*
873 * Call this to report error for your variable that should not
874 * get a boolean value (i.e. "[my] var" means "true").
875 */
876int config_error_nonbool(const char *var)
877{
878    return error("Missing value for '%s'", var);
879}
880

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