#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 <dirent.h>
#include <sys/time.h>                   /* getrlimit */
#include <sys/resource.h>               /* getrlimit */
#include <ftw.h>
#include <sys/stat.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));                          \
        goto out_free;                                          \
} } while (0)

#define TOPIC_DEPTH 256
static char *topic_array[TOPIC_DEPTH];
static int   topic_level;

static char *get_topic(void)
{
        char *tp_old, *tp = NULL;
        int i;

        for (i = 0; i < topic_level + 1; i++) {
                int n;

                tp_old = tp;
                n = asprintf(&tp, "%s%s", tp ?: "", topic_array[i]);
                if (n < 0) {
                        pr_info("%s: asprintf() error %s\n", prog);
                        return NULL;
                }
                free(tp_old);
        }

        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(int level, char *bname)
{
        char *topic;

        level -= 2;

        if (level >= TOPIC_DEPTH)
                return -EINVAL;

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

        free(topic_array[topic_level]);
        topic_array[topic_level] = topic;
        topic_level              = level;
        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;
}

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;
}

/* 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 = -EIO;
        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;
                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);
                        }
                        /* 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);

                err = func(data, name, real_event(name, event), desc, long_desc,
                           pmu, unit, perpkg, metric_expr, metric_name, metric_group);
                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);
                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", basename(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 == '-')
                        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 process_one_file(const char *fpath, const struct stat *sb,
                            int typeflag, struct FTW *ftwbuf)
{
        char *tblname, *bname  = (char *) fpath + ftwbuf->base;
        int is_dir  = typeflag == FTW_D;
        int is_file = typeflag == FTW_F;
        int level   = ftwbuf->level;
        int err = 0;

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

        /* base dir */
        if (level == 0)
                return 0;

        /* model directory, reset topic */
        if (level == 1 && 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).
         *
         * TODO: Allow for multiple mapfiles? Punt for now.
         */
        if (level == 1 && is_file) {
                if (!strncmp(bname, "mapfile.csv", 11)) {
                        if (mapfile) {
                                pr_info("%s: Many mapfiles? Using %s, ignoring %s\n",
                                                prog, mapfile, fpath);
                        } else {
                                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) {
                char *suffix = bname + strlen(bname) - 5;

                if (strncmp(suffix, ".json", 5)) {
                        pr_info("%s: Ignoring file without .json suffix %s\n", prog,
                                fpath);
                        return 0;
                }
        }

        if (level > 1 && add_topic(level, 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, 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 */
                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);
        return 0;
}