jevents.c

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#define  _XOPEN_SOURCE 500  /* needed for nftw() */
#define  _GNU_SOURCE        /* needed for asprintf() */

/* Parse event JSON files */

/*
 * Copyright (c) 2014, Intel Corporation
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <ctype.h>
#include <unistd.h>
#include <stdarg.h>
#include <libgen.h>
#include <limits.h>
#include <dirent.h>
#include <sys/time.h>           /* getrlimit */
#include <sys/resource.h>       /* getrlimit */
#include <ftw.h>
#include <sys/stat.h>
#include <linux/list.h>
#include "jsmn.h"
#include "json.h"
#include "jevents.h"

int verbose;
char *prog;

int eprintf(int level, int var, const char *fmt, ...)
{

    int ret;
    va_list args;

    if (var < level)
        return 0;

    va_start(args, fmt);

    ret = vfprintf(stderr, fmt, args);

    va_end(args);

    return ret;
}

__attribute__((weak)) char *get_cpu_str(void)
{
    return NULL;
}

static void addfield(char *map, char **dst, const char *sep,
             const char *a, jsmntok_t *bt)
{
    unsigned int len = strlen(a) + 1 + strlen(sep);
    int olen = *dst ? strlen(*dst) : 0;
    int blen = bt ? json_len(bt) : 0;
    char *out;

    out = realloc(*dst, len + olen + blen);
    if (!out) {
        /* Don't add field in this case */
        return;
    }
    *dst = out;

    if (!olen)
        *(*dst) = 0;
    else
        strcat(*dst, sep);
    strcat(*dst, a);
    if (bt)
        strncat(*dst, map + bt->start, blen);
}

static void fixname(char *s)
{
    for (; *s; s++)
        *s = tolower(*s);
}

static void fixdesc(char *s)
{
    char *e = s + strlen(s);

    /* Remove trailing dots that look ugly in perf list */
    --e;
    while (e >= s && isspace(*e))
        --e;
    if (*e == '.')
        *e = 0;
}

/* Add escapes for '\' so they are proper C strings. */
static char *fixregex(char *s)
{
    int len = 0;
    int esc_count = 0;
    char *fixed = NULL;
    char *p, *q;

    /* Count the number of '\' in string */
    for (p = s; *p; p++) {
        ++len;
        if (*p == '\\')
            ++esc_count;
    }

    if (esc_count == 0)
        return s;

    /* allocate space for a new string */
    fixed = (char *) malloc(len + 1);
    if (!fixed)
        return NULL;

    /* copy over the characters */
    q = fixed;
    for (p = s; *p; p++) {
        if (*p == '\\') {
            *q = '\\';
            ++q;
        }
        *q = *p;
        ++q;
    }
    *q = '\0';
    return fixed;
}

static struct msrmap {
    const char *num;
    const char *pname;
} msrmap[] = {
    { "0x3F6", "ldlat=" },
    { "0x1A6", "offcore_rsp=" },
    { "0x1A7", "offcore_rsp=" },
    { "0x3F7", "frontend=" },
    { NULL, NULL }
};

static struct field {
    const char *field;
    const char *kernel;
} fields[] = {
    { "UMask",  "umask=" },
    { "CounterMask", "cmask=" },
    { "Invert", "inv=" },
    { "AnyThread",  "any=" },
    { "EdgeDetect", "edge=" },
    { "SampleAfterValue", "period=" },
    { "FCMask", "fc_mask=" },
    { "PortMask",   "ch_mask=" },
    { NULL, NULL }
};

static void cut_comma(char *map, jsmntok_t *newval)
{
    int i;

    /* Cut off everything after comma */
    for (i = newval->start; i < newval->end; i++) {
        if (map[i] == ',')
            newval->end = i;
    }
}

static int match_field(char *map, jsmntok_t *field, int nz,
               char **event, jsmntok_t *val)
{
    struct field *f;
    jsmntok_t newval = *val;

    for (f = fields; f->field; f++)
        if (json_streq(map, field, f->field) && nz) {
            cut_comma(map, &newval);
            addfield(map, event, ",", f->kernel, &newval);
            return 1;
        }
    return 0;
}

static struct msrmap *lookup_msr(char *map, jsmntok_t *val)
{
    jsmntok_t newval = *val;
    static bool warned;
    int i;

    cut_comma(map, &newval);
    for (i = 0; msrmap[i].num; i++)
        if (json_streq(map, &newval, msrmap[i].num))
            return &msrmap[i];
    if (!warned) {
        warned = true;
        pr_err("%s: Unknown MSR in event file %.*s\n", prog,
            json_len(val), map + val->start);
    }
    return NULL;
}

static struct map {
    const char *json;
    const char *perf;
} unit_to_pmu[] = {
    { "CBO", "uncore_cbox" },
    { "QPI LL", "uncore_qpi" },
    { "SBO", "uncore_sbox" },
    { "iMPH-U", "uncore_arb" },
    {}
};

static const char *field_to_perf(struct map *table, char *map, jsmntok_t *val)
{
    int i;

    for (i = 0; table[i].json; i++) {
        if (json_streq(map, val, table[i].json))
            return table[i].perf;
    }
    return NULL;
}

#define EXPECT(e, t, m) do { if (!(e)) {            \
    jsmntok_t *loc = (t);                   \
    if (!(t)->start && (t) > tokens)            \
        loc = (t) - 1;                  \
    pr_err("%s:%d: " m ", got %s\n", fn,            \
           json_line(map, loc),             \
           json_name(t));                   \
    err = -EIO;                     \
    goto out_free;                      \
} } while (0)

static char *topic;

static char *get_topic(void)
{
    char *tp;
    int i;

    /* tp is free'd in process_one_file() */
    i = asprintf(&tp, "%s", topic);
    if (i < 0) {
        pr_info("%s: asprintf() error %s\n", prog);
        return NULL;
    }

    for (i = 0; i < (int) strlen(tp); i++) {
        char c = tp[i];

        if (c == '-')
            tp[i] = ' ';
        else if (c == '.') {
            tp[i] = '\0';
            break;
        }
    }

    return tp;
}

static int add_topic(char *bname)
{
    free(topic);
    topic = strdup(bname);
    if (!topic) {
        pr_info("%s: strdup() error %s for file %s\n", prog,
                strerror(errno), bname);
        return -ENOMEM;
    }
    return 0;
}

struct perf_entry_data {
    FILE *outfp;
    char *topic;
};

static int close_table;

static void print_events_table_prefix(FILE *fp, const char *tblname)
{
    fprintf(fp, "struct pmu_event %s[] = {\n", tblname);
    close_table = 1;
}

static int print_events_table_entry(void *data, char *name, char *event,
                    char *desc, char *long_desc,
                    char *pmu, char *unit, char *perpkg,
                    char *metric_expr,
                    char *metric_name, char *metric_group)
{
    struct perf_entry_data *pd = data;
    FILE *outfp = pd->outfp;
    char *topic = pd->topic;

    /*
     * TODO: Remove formatting chars after debugging to reduce
     *   string lengths.
     */
    fprintf(outfp, "{\n");

    if (name)
        fprintf(outfp, "\t.name = \"%s\",\n", name);
    if (event)
        fprintf(outfp, "\t.event = \"%s\",\n", event);
    fprintf(outfp, "\t.desc = \"%s\",\n", desc);
    fprintf(outfp, "\t.topic = \"%s\",\n", topic);
    if (long_desc && long_desc[0])
        fprintf(outfp, "\t.long_desc = \"%s\",\n", long_desc);
    if (pmu)
        fprintf(outfp, "\t.pmu = \"%s\",\n", pmu);
    if (unit)
        fprintf(outfp, "\t.unit = \"%s\",\n", unit);
    if (perpkg)
        fprintf(outfp, "\t.perpkg = \"%s\",\n", perpkg);
    if (metric_expr)
        fprintf(outfp, "\t.metric_expr = \"%s\",\n", metric_expr);
    if (metric_name)
        fprintf(outfp, "\t.metric_name = \"%s\",\n", metric_name);
    if (metric_group)
        fprintf(outfp, "\t.metric_group = \"%s\",\n", metric_group);
    fprintf(outfp, "},\n");

    return 0;
}

struct event_struct {
    struct list_head list;
    char *name;
    char *event;
    char *desc;
    char *long_desc;
    char *pmu;
    char *unit;
    char *perpkg;
    char *metric_expr;
    char *metric_name;
    char *metric_group;
};

#define ADD_EVENT_FIELD(field) do { if (field) {        \
    es->field = strdup(field);              \
    if (!es->field)                     \
        goto out_free;                  \
} } while (0)

#define FREE_EVENT_FIELD(field) free(es->field)

#define TRY_FIXUP_FIELD(field) do { if (es->field && !*field) {\
    *field = strdup(es->field);             \
    if (!*field)                        \
        return -ENOMEM;                 \
} } while (0)

#define FOR_ALL_EVENT_STRUCT_FIELDS(op) do {            \
    op(name);                       \
    op(event);                      \
    op(desc);                       \
    op(long_desc);                      \
    op(pmu);                        \
    op(unit);                       \
    op(perpkg);                     \
    op(metric_expr);                    \
    op(metric_name);                    \
    op(metric_group);                   \
} while (0)

static LIST_HEAD(arch_std_events);

static void free_arch_std_events(void)
{
    struct event_struct *es, *next;

    list_for_each_entry_safe(es, next, &arch_std_events, list) {
        FOR_ALL_EVENT_STRUCT_FIELDS(FREE_EVENT_FIELD);
        list_del(&es->list);
        free(es);
    }
}

static int save_arch_std_events(void *data, char *name, char *event,
                char *desc, char *long_desc, char *pmu,
                char *unit, char *perpkg, char *metric_expr,
                char *metric_name, char *metric_group)
{
    struct event_struct *es;
    struct stat *sb = data;

    es = malloc(sizeof(*es));
    if (!es)
        return -ENOMEM;
    memset(es, 0, sizeof(*es));
    FOR_ALL_EVENT_STRUCT_FIELDS(ADD_EVENT_FIELD);
    list_add_tail(&es->list, &arch_std_events);
    return 0;
out_free:
    FOR_ALL_EVENT_STRUCT_FIELDS(FREE_EVENT_FIELD);
    free(es);
    return -ENOMEM;
}

static void print_events_table_suffix(FILE *outfp)
{
    fprintf(outfp, "{\n");

    fprintf(outfp, "\t.name = 0,\n");
    fprintf(outfp, "\t.event = 0,\n");
    fprintf(outfp, "\t.desc = 0,\n");

    fprintf(outfp, "},\n");
    fprintf(outfp, "};\n");
    close_table = 0;
}

static struct fixed {
    const char *name;
    const char *event;
} fixed[] = {
    { "inst_retired.any", "event=0xc0" },
    { "inst_retired.any_p", "event=0xc0" },
    { "cpu_clk_unhalted.ref", "event=0x0,umask=0x03" },
    { "cpu_clk_unhalted.thread", "event=0x3c" },
    { "cpu_clk_unhalted.thread_any", "event=0x3c,any=1" },
    { NULL, NULL},
};

/*
 * Handle different fixed counter encodings between JSON and perf.
 */
static char *real_event(const char *name, char *event)
{
    int i;

    if (!name)
        return NULL;

    for (i = 0; fixed[i].name; i++)
        if (!strcasecmp(name, fixed[i].name))
            return (char *)fixed[i].event;
    return event;
}

static int
try_fixup(const char *fn, char *arch_std, char **event, char **desc,
      char **name, char **long_desc, char **pmu, char **filter,
      char **perpkg, char **unit, char **metric_expr, char **metric_name,
      char **metric_group, unsigned long long eventcode)
{
    /* try to find matching event from arch standard values */
    struct event_struct *es;

    list_for_each_entry(es, &arch_std_events, list) {
        if (!strcmp(arch_std, es->name)) {
            if (!eventcode && es->event) {
                /* allow EventCode to be overridden */
                free(*event);
                *event = NULL;
            }
            FOR_ALL_EVENT_STRUCT_FIELDS(TRY_FIXUP_FIELD);
            return 0;
        }
    }

    pr_err("%s: could not find matching %s for %s\n",
                    prog, arch_std, fn);
    return -1;
}

/* Call func with each event in the json file */
int json_events(const char *fn,
      int (*func)(void *data, char *name, char *event, char *desc,
              char *long_desc,
              char *pmu, char *unit, char *perpkg,
              char *metric_expr,
              char *metric_name, char *metric_group),
      void *data)
{
    int err;
    size_t size;
    jsmntok_t *tokens, *tok;
    int i, j, len;
    char *map;
    char buf[128];

    if (!fn)
        return -ENOENT;

    tokens = parse_json(fn, &map, &size, &len);
    if (!tokens)
        return -EIO;
    EXPECT(tokens->type == JSMN_ARRAY, tokens, "expected top level array");
    tok = tokens + 1;
    for (i = 0; i < tokens->size; i++) {
        char *event = NULL, *desc = NULL, *name = NULL;
        char *long_desc = NULL;
        char *extra_desc = NULL;
        char *pmu = NULL;
        char *filter = NULL;
        char *perpkg = NULL;
        char *unit = NULL;
        char *metric_expr = NULL;
        char *metric_name = NULL;
        char *metric_group = NULL;
        char *arch_std = NULL;
        unsigned long long eventcode = 0;
        struct msrmap *msr = NULL;
        jsmntok_t *msrval = NULL;
        jsmntok_t *precise = NULL;
        jsmntok_t *obj = tok++;

        EXPECT(obj->type == JSMN_OBJECT, obj, "expected object");
        for (j = 0; j < obj->size; j += 2) {
            jsmntok_t *field, *val;
            int nz;
            char *s;

            field = tok + j;
            EXPECT(field->type == JSMN_STRING, tok + j,
                   "Expected field name");
            val = tok + j + 1;
            EXPECT(val->type == JSMN_STRING, tok + j + 1,
                   "Expected string value");

            nz = !json_streq(map, val, "0");
            if (match_field(map, field, nz, &event, val)) {
                /* ok */
            } else if (json_streq(map, field, "EventCode")) {
                char *code = NULL;
                addfield(map, &code, "", "", val);
                eventcode |= strtoul(code, NULL, 0);
                free(code);
            } else if (json_streq(map, field, "ExtSel")) {
                char *code = NULL;
                addfield(map, &code, "", "", val);
                eventcode |= strtoul(code, NULL, 0) << 21;
                free(code);
            } else if (json_streq(map, field, "EventName")) {
                addfield(map, &name, "", "", val);
            } else if (json_streq(map, field, "BriefDescription")) {
                addfield(map, &desc, "", "", val);
                fixdesc(desc);
            } else if (json_streq(map, field,
                         "PublicDescription")) {
                addfield(map, &long_desc, "", "", val);
                fixdesc(long_desc);
            } else if (json_streq(map, field, "PEBS") && nz) {
                precise = val;
            } else if (json_streq(map, field, "MSRIndex") && nz) {
                msr = lookup_msr(map, val);
            } else if (json_streq(map, field, "MSRValue")) {
                msrval = val;
            } else if (json_streq(map, field, "Errata") &&
                   !json_streq(map, val, "null")) {
                addfield(map, &extra_desc, ". ",
                    " Spec update: ", val);
            } else if (json_streq(map, field, "Data_LA") && nz) {
                addfield(map, &extra_desc, ". ",
                    " Supports address when precise",
                    NULL);
            } else if (json_streq(map, field, "Unit")) {
                const char *ppmu;

                ppmu = field_to_perf(unit_to_pmu, map, val);
                if (ppmu) {
                    pmu = strdup(ppmu);
                } else {
                    if (!pmu)
                        pmu = strdup("uncore_");
                    addfield(map, &pmu, "", "", val);
                    for (s = pmu; *s; s++)
                        *s = tolower(*s);
                }
                addfield(map, &desc, ". ", "Unit: ", NULL);
                addfield(map, &desc, "", pmu, NULL);
                addfield(map, &desc, "", " ", NULL);
            } else if (json_streq(map, field, "Filter")) {
                addfield(map, &filter, "", "", val);
            } else if (json_streq(map, field, "ScaleUnit")) {
                addfield(map, &unit, "", "", val);
            } else if (json_streq(map, field, "PerPkg")) {
                addfield(map, &perpkg, "", "", val);
            } else if (json_streq(map, field, "MetricName")) {
                addfield(map, &metric_name, "", "", val);
            } else if (json_streq(map, field, "MetricGroup")) {
                addfield(map, &metric_group, "", "", val);
            } else if (json_streq(map, field, "MetricExpr")) {
                addfield(map, &metric_expr, "", "", val);
                for (s = metric_expr; *s; s++)
                    *s = tolower(*s);
            } else if (json_streq(map, field, "ArchStdEvent")) {
                addfield(map, &arch_std, "", "", val);
                for (s = arch_std; *s; s++)
                    *s = tolower(*s);
            }
            /* ignore unknown fields */
        }
        if (precise && desc && !strstr(desc, "(Precise Event)")) {
            if (json_streq(map, precise, "2"))
                addfield(map, &extra_desc, " ",
                        "(Must be precise)", NULL);
            else
                addfield(map, &extra_desc, " ",
                        "(Precise event)", NULL);
        }
        snprintf(buf, sizeof buf, "event=%#llx", eventcode);
        addfield(map, &event, ",", buf, NULL);
        if (desc && extra_desc)
            addfield(map, &desc, " ", extra_desc, NULL);
        if (long_desc && extra_desc)
            addfield(map, &long_desc, " ", extra_desc, NULL);
        if (filter)
            addfield(map, &event, ",", filter, NULL);
        if (msr != NULL)
            addfield(map, &event, ",", msr->pname, msrval);
        if (name)
            fixname(name);

        if (arch_std) {
            /*
             * An arch standard event is referenced, so try to
             * fixup any unassigned values.
             */
            err = try_fixup(fn, arch_std, &event, &desc, &name,
                    &long_desc, &pmu, &filter, &perpkg,
                    &unit, &metric_expr, &metric_name,
                    &metric_group, eventcode);
            if (err)
                goto free_strings;
        }
        err = func(data, name, real_event(name, event), desc, long_desc,
               pmu, unit, perpkg, metric_expr, metric_name, metric_group);
free_strings:
        free(event);
        free(desc);
        free(name);
        free(long_desc);
        free(extra_desc);
        free(pmu);
        free(filter);
        free(perpkg);
        free(unit);
        free(metric_expr);
        free(metric_name);
        free(metric_group);
        free(arch_std);

        if (err)
            break;
        tok += j;
    }
    EXPECT(tok - tokens == len, tok, "unexpected objects at end");
    err = 0;
out_free:
    free_json(map, size, tokens);
    return err;
}

static char *file_name_to_table_name(char *fname)
{
    unsigned int i;
    int n;
    int c;
    char *tblname;

    /*
     * Ensure tablename starts with alphabetic character.
     * Derive rest of table name from basename of the JSON file,
     * replacing hyphens and stripping out .json suffix.
     */
    n = asprintf(&tblname, "pme_%s", fname);
    if (n < 0) {
        pr_info("%s: asprintf() error %s for file %s\n", prog,
                strerror(errno), fname);
        return NULL;
    }

    for (i = 0; i < strlen(tblname); i++) {
        c = tblname[i];

        if (c == '-' || c == '/')
            tblname[i] = '_';
        else if (c == '.') {
            tblname[i] = '\0';
            break;
        } else if (!isalnum(c) && c != '_') {
            pr_err("%s: Invalid character '%c' in file name %s\n",
                    prog, c, basename(fname));
            free(tblname);
            tblname = NULL;
            break;
        }
    }

    return tblname;
}

static void print_mapping_table_prefix(FILE *outfp)
{
    fprintf(outfp, "struct pmu_events_map pmu_events_map[] = {\n");
}

static void print_mapping_table_suffix(FILE *outfp)
{
    /*
     * Print the terminating, NULL entry.
     */
    fprintf(outfp, "{\n");
    fprintf(outfp, "\t.cpuid = 0,\n");
    fprintf(outfp, "\t.version = 0,\n");
    fprintf(outfp, "\t.type = 0,\n");
    fprintf(outfp, "\t.table = 0,\n");
    fprintf(outfp, "},\n");

    /* and finally, the closing curly bracket for the struct */
    fprintf(outfp, "};\n");
}

static int process_mapfile(FILE *outfp, char *fpath)
{
    int n = 16384;
    FILE *mapfp;
    char *save = NULL;
    char *line, *p;
    int line_num;
    char *tblname;

    pr_info("%s: Processing mapfile %s\n", prog, fpath);

    line = malloc(n);
    if (!line)
        return -1;

    mapfp = fopen(fpath, "r");
    if (!mapfp) {
        pr_info("%s: Error %s opening %s\n", prog, strerror(errno),
                fpath);
        return -1;
    }

    print_mapping_table_prefix(outfp);

    /* Skip first line (header) */
    p = fgets(line, n, mapfp);
    if (!p)
        goto out;

    line_num = 1;
    while (1) {
        char *cpuid, *version, *type, *fname;

        line_num++;
        p = fgets(line, n, mapfp);
        if (!p)
            break;

        if (line[0] == '#' || line[0] == '\n')
            continue;

        if (line[strlen(line)-1] != '\n') {
            /* TODO Deal with lines longer than 16K */
            pr_info("%s: Mapfile %s: line %d too long, aborting\n",
                    prog, fpath, line_num);
            return -1;
        }
        line[strlen(line)-1] = '\0';

        cpuid = fixregex(strtok_r(p, ",", &save));
        version = strtok_r(NULL, ",", &save);
        fname = strtok_r(NULL, ",", &save);
        type = strtok_r(NULL, ",", &save);

        tblname = file_name_to_table_name(fname);
        fprintf(outfp, "{\n");
        fprintf(outfp, "\t.cpuid = \"%s\",\n", cpuid);
        fprintf(outfp, "\t.version = \"%s\",\n", version);
        fprintf(outfp, "\t.type = \"%s\",\n", type);

        /*
         * CHECK: We can't use the type (eg "core") field in the
         * table name. For us to do that, we need to somehow tweak
         * the other caller of file_name_to_table(), process_json()
         * to determine the type. process_json() file has no way
         * of knowing these are "core" events unless file name has
         * core in it. If filename has core in it, we can safely
         * ignore the type field here also.
         */
        fprintf(outfp, "\t.table = %s\n", tblname);
        fprintf(outfp, "},\n");
    }

out:
    print_mapping_table_suffix(outfp);
    return 0;
}

/*
 * If we fail to locate/process JSON and map files, create a NULL mapping
 * table. This would at least allow perf to build even if we can't find/use
 * the aliases.
 */
static void create_empty_mapping(const char *output_file)
{
    FILE *outfp;

    pr_info("%s: Creating empty pmu_events_map[] table\n", prog);

    /* Truncate file to clear any partial writes to it */
    outfp = fopen(output_file, "w");
    if (!outfp) {
        perror("fopen()");
        _Exit(1);
    }

    fprintf(outfp, "#include \"../../pmu-events/pmu-events.h\"\n");
    print_mapping_table_prefix(outfp);
    print_mapping_table_suffix(outfp);
    fclose(outfp);
}

static int get_maxfds(void)
{
    struct rlimit rlim;

    if (getrlimit(RLIMIT_NOFILE, &rlim) == 0)
        return min((int)rlim.rlim_max / 2, 512);

    return 512;
}

/*
 * nftw() doesn't let us pass an argument to the processing function,
 * so use a global variables.
 */
static FILE *eventsfp;
static char *mapfile;

static int is_leaf_dir(const char *fpath)
{
    DIR *d;
    struct dirent *dir;
    int res = 1;

    d = opendir(fpath);
    if (!d)
        return 0;

    while ((dir = readdir(d)) != NULL) {
        if (!strcmp(dir->d_name, ".") || !strcmp(dir->d_name, ".."))
            continue;

        if (dir->d_type == DT_DIR) {
            res = 0;
            break;
        } else if (dir->d_type == DT_UNKNOWN) {
            char path[PATH_MAX];
            struct stat st;

            sprintf(path, "%s/%s", fpath, dir->d_name);
            if (stat(path, &st))
                break;

            if (S_ISDIR(st.st_mode)) {
                res = 0;
                break;
            }
        }
    }

    closedir(d);

    return res;
}

static int is_json_file(const char *name)
{
    const char *suffix;

    if (strlen(name) < 5)
        return 0;

    suffix = name + strlen(name) - 5;

    if (strncmp(suffix, ".json", 5) == 0)
        return 1;
    return 0;
}

static int preprocess_arch_std_files(const char *fpath, const struct stat *sb,
                int typeflag, struct FTW *ftwbuf)
{
    int level = ftwbuf->level;
    int is_file = typeflag == FTW_F;

    if (level == 1 && is_file && is_json_file(fpath))
        return json_events(fpath, save_arch_std_events, (void *)sb);

    return 0;
}

static int process_one_file(const char *fpath, const struct stat *sb,
                int typeflag, struct FTW *ftwbuf)
{
    char *tblname, *bname;
    int is_dir  = typeflag == FTW_D;
    int is_file = typeflag == FTW_F;
    int level   = ftwbuf->level;
    int err = 0;

    if (level == 2 && is_dir) {
        /*
         * For level 2 directory, bname will include parent name,
         * like vendor/platform. So search back from platform dir
         * to find this.
         */
        bname = (char *) fpath + ftwbuf->base - 2;
        for (;;) {
            if (*bname == '/')
                break;
            bname--;
        }
        bname++;
    } else
        bname = (char *) fpath + ftwbuf->base;

    pr_debug("%s %d %7jd %-20s %s\n",
         is_file ? "f" : is_dir ? "d" : "x",
         level, sb->st_size, bname, fpath);

    /* base dir or too deep */
    if (level == 0 || level > 3)
        return 0;


    /* model directory, reset topic */
    if ((level == 1 && is_dir && is_leaf_dir(fpath)) ||
        (level == 2 && is_dir)) {
        if (close_table)
            print_events_table_suffix(eventsfp);

        /*
         * Drop file name suffix. Replace hyphens with underscores.
         * Fail if file name contains any alphanum characters besides
         * underscores.
         */
        tblname = file_name_to_table_name(bname);
        if (!tblname) {
            pr_info("%s: Error determining table name for %s\n", prog,
                bname);
            return -1;
        }

        print_events_table_prefix(eventsfp, tblname);
        return 0;
    }

    /*
     * Save the mapfile name for now. We will process mapfile
     * after processing all JSON files (so we can write out the
     * mapping table after all PMU events tables).
     *
     */
    if (level == 1 && is_file) {
        if (!strcmp(bname, "mapfile.csv")) {
            mapfile = strdup(fpath);
            return 0;
        }

        pr_info("%s: Ignoring file %s\n", prog, fpath);
        return 0;
    }

    /*
     * If the file name does not have a .json extension,
     * ignore it. It could be a readme.txt for instance.
     */
    if (is_file) {
        if (!is_json_file(bname)) {
            pr_info("%s: Ignoring file without .json suffix %s\n", prog,
                fpath);
            return 0;
        }
    }

    if (level > 1 && add_topic(bname))
        return -ENOMEM;

    /*
     * Assume all other files are JSON files.
     *
     * If mapfile refers to 'power7_core.json', we create a table
     * named 'power7_core'. Any inconsistencies between the mapfile
     * and directory tree could result in build failure due to table
     * names not being found.
     *
     * Atleast for now, be strict with processing JSON file names.
     * i.e. if JSON file name cannot be mapped to C-style table name,
     * fail.
     */
    if (is_file) {
        struct perf_entry_data data = {
            .topic = get_topic(),
            .outfp = eventsfp,
        };

        err = json_events(fpath, print_events_table_entry, &data);

        free(data.topic);
    }

    return err;
}

#ifndef PATH_MAX
#define PATH_MAX    4096
#endif

/*
 * Starting in directory 'start_dirname', find the "mapfile.csv" and
 * the set of JSON files for the architecture 'arch'.
 *
 * From each JSON file, create a C-style "PMU events table" from the
 * JSON file (see struct pmu_event).
 *
 * From the mapfile, create a mapping between the CPU revisions and
 * PMU event tables (see struct pmu_events_map).
 *
 * Write out the PMU events tables and the mapping table to pmu-event.c.
 */
int main(int argc, char *argv[])
{
    int rc;
    int maxfds;
    char ldirname[PATH_MAX];

    const char *arch;
    const char *output_file;
    const char *start_dirname;
    struct stat stbuf;

    prog = basename(argv[0]);
    if (argc < 4) {
        pr_err("Usage: %s <arch> <starting_dir> <output_file>\n", prog);
        return 1;
    }

    arch = argv[1];
    start_dirname = argv[2];
    output_file = argv[3];

    if (argc > 4)
        verbose = atoi(argv[4]);

    eventsfp = fopen(output_file, "w");
    if (!eventsfp) {
        pr_err("%s Unable to create required file %s (%s)\n",
                prog, output_file, strerror(errno));
        return 2;
    }

    sprintf(ldirname, "%s/%s", start_dirname, arch);

    /* If architecture does not have any event lists, bail out */
    if (stat(ldirname, &stbuf) < 0) {
        pr_info("%s: Arch %s has no PMU event lists\n", prog, arch);
        goto empty_map;
    }

    /* Include pmu-events.h first */
    fprintf(eventsfp, "#include \"../../pmu-events/pmu-events.h\"\n");

    /*
     * The mapfile allows multiple CPUids to point to the same JSON file,
     * so, not sure if there is a need for symlinks within the pmu-events
     * directory.
     *
     * For now, treat symlinks of JSON files as regular files and create
     * separate tables for each symlink (presumably, each symlink refers
     * to specific version of the CPU).
     */

    maxfds = get_maxfds();
    mapfile = NULL;
    rc = nftw(ldirname, preprocess_arch_std_files, maxfds, 0);
    if (rc && verbose) {
        pr_info("%s: Error preprocessing arch standard files %s\n",
            prog, ldirname);
        goto empty_map;
    } else if (rc < 0) {
        /* Make build fail */
        free_arch_std_events();
        return 1;
    } else if (rc) {
        goto empty_map;
    }

    rc = nftw(ldirname, process_one_file, maxfds, 0);
    if (rc && verbose) {
        pr_info("%s: Error walking file tree %s\n", prog, ldirname);
        goto empty_map;
    } else if (rc < 0) {
        /* Make build fail */
        free_arch_std_events();
        return 1;
    } else if (rc) {
        goto empty_map;
    }

    if (close_table)
        print_events_table_suffix(eventsfp);

    if (!mapfile) {
        pr_info("%s: No CPU->JSON mapping?\n", prog);
        goto empty_map;
    }

    if (process_mapfile(eventsfp, mapfile)) {
        pr_info("%s: Error processing mapfile %s\n", prog, mapfile);
        /* Make build fail */
        return 1;
    }

    return 0;

empty_map:
    fclose(eventsfp);
    create_empty_mapping(output_file);
    free_arch_std_events();
    return 0;
}