/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2005-2007, Joseph Koshy
 * Copyright (c) 2007 The FreeBSD Foundation
 * All rights reserved.
 *
 * Portions of this software were developed by A. Joseph Koshy under
 * sponsorship from the FreeBSD Foundation and Google, Inc.
 *
 * 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 AUTHOR 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 AUTHOR 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.
 */

/*
 * Transform a hwpmc(4) log into human readable form, and into
 * gprof(1) compatible profiles.
 */

#include <sys/param.h>
#include <sys/endian.h>
#include <sys/gmon.h>
#include <sys/imgact_aout.h>
#include <sys/imgact_elf.h>
#include <sys/mman.h>
#include <sys/pmc.h>
#include <sys/queue.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/wait.h>

#include <netinet/in.h>

#include <assert.h>
#include <curses.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <gelf.h>
#include <inttypes.h>
#include <libgen.h>
#include <limits.h>
#include <netdb.h>
#include <pmc.h>
#include <pmclog.h>
#include <sysexits.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "pmcstat.h"
#include "pmcstat_log.h"
#include "pmcstat_top.h"
#include "pmcpl_callgraph.h"

#define min(A,B)                ((A) < (B) ? (A) : (B))
#define max(A,B)                ((A) > (B) ? (A) : (B))

/* Get the sample value in percent related to nsamples. */
#define PMCPL_CG_COUNTP(a) \
        ((a)->pcg_count * 100.0 / nsamples)

/*
 * The toplevel CG nodes (i.e., with rank == 0) are placed in a hash table.
 */

struct pmcstat_cgnode_hash_list pmcstat_cgnode_hash[PMCSTAT_NHASH];
int pmcstat_cgnode_hash_count;

static pmcstat_interned_string pmcstat_previous_filename_printed;

static struct pmcstat_cgnode *
pmcstat_cgnode_allocate(struct pmcstat_image *image, uintfptr_t pc)
{
        struct pmcstat_cgnode *cg;

        if ((cg = malloc(sizeof(*cg))) == NULL)
                err(EX_OSERR, "ERROR: Cannot allocate callgraph node");

        cg->pcg_image = image;
        cg->pcg_func = pc;

        cg->pcg_count = 0;
        cg->pcg_nchildren = 0;
        LIST_INIT(&cg->pcg_children);

        return (cg);
}

/*
 * Free a node and its children.
 */
static void
pmcstat_cgnode_free(struct pmcstat_cgnode *cg)
{
        struct pmcstat_cgnode *cgc, *cgtmp;

        LIST_FOREACH_SAFE(cgc, &cg->pcg_children, pcg_sibling, cgtmp)
                pmcstat_cgnode_free(cgc);
        free(cg);
}

/*
 * Look for a callgraph node associated with pmc `pmcid' in the global
 * hash table that corresponds to the given `pc' value in the process
 * `pp'.
 */
static struct pmcstat_cgnode *
pmcstat_cgnode_hash_lookup_pc(struct pmcstat_process *pp, pmc_id_t pmcid,
    uintfptr_t pc, int usermode)
{
        struct pmcstat_pcmap *ppm;
        struct pmcstat_symbol *sym;
        struct pmcstat_image *image;
        struct pmcstat_cgnode *cg;
        struct pmcstat_cgnode_hash *h;
        uintfptr_t loadaddress;
        unsigned int i, hash;

        ppm = pmcstat_process_find_map(usermode ? pp : pmcstat_kernproc, pc);
        if (ppm == NULL)
                return (NULL);

        image = ppm->ppm_image;

        loadaddress = ppm->ppm_lowpc + image->pi_vaddr - image->pi_start;
        pc -= loadaddress;      /* Convert to an offset in the image. */

        /*
         * Try determine the function at this offset.  If we can't
         * find a function round leave the `pc' value alone.
         */
        if (!(args.pa_flags & (FLAG_SKIP_TOP_FN_RES | FLAG_SHOW_OFFSET))) {
                if ((sym = pmcstat_symbol_search(image, pc)) != NULL)
                        pc = sym->ps_start;
                else
                        pmcstat_stats.ps_samples_unknown_function++;
        }

        for (hash = i = 0; i < sizeof(uintfptr_t); i++)
                hash += (pc >> i) & 0xFF;

        hash &= PMCSTAT_HASH_MASK;

        cg = NULL;
        LIST_FOREACH(h, &pmcstat_cgnode_hash[hash], pch_next)
        {
                if (h->pch_pmcid != pmcid)
                        continue;

                cg = h->pch_cgnode;

                assert(cg != NULL);

                if (cg->pcg_image == image && cg->pcg_func == pc)
                        return (cg);
        }

        /*
         * We haven't seen this (pmcid, pc) tuple yet, so allocate a
         * new callgraph node and a new hash table entry for it.
         */
        cg = pmcstat_cgnode_allocate(image, pc);
        if ((h = malloc(sizeof(*h))) == NULL)
                err(EX_OSERR, "ERROR: Could not allocate callgraph node");

        h->pch_pmcid = pmcid;
        h->pch_cgnode = cg;
        LIST_INSERT_HEAD(&pmcstat_cgnode_hash[hash], h, pch_next);

        pmcstat_cgnode_hash_count++;

        return (cg);
}

/*
 * Compare two callgraph nodes for sorting.
 */
static int
pmcstat_cgnode_compare(const void *a, const void *b)
{
        const struct pmcstat_cgnode *const *pcg1, *const *pcg2, *cg1, *cg2;

        pcg1 = (const struct pmcstat_cgnode *const *) a;
        cg1 = *pcg1;
        pcg2 = (const struct pmcstat_cgnode *const *) b;
        cg2 = *pcg2;

        /* Sort in reverse order */
        if (cg1->pcg_count < cg2->pcg_count)
                return (1);
        if (cg1->pcg_count > cg2->pcg_count)
                return (-1);
        return (0);
}

/*
 * Find (allocating if a needed) a callgraph node in the given
 * parent with the same (image, pcoffset) pair.
 */

static struct pmcstat_cgnode *
pmcstat_cgnode_find(struct pmcstat_cgnode *parent, struct pmcstat_image *image,
    uintfptr_t pcoffset)
{
        struct pmcstat_cgnode *child;

        LIST_FOREACH(child, &parent->pcg_children, pcg_sibling) {
                if (child->pcg_image == image &&
                    child->pcg_func == pcoffset)
                        return (child);
        }

        /*
         * Allocate a new structure.
         */

        child = pmcstat_cgnode_allocate(image, pcoffset);

        /*
         * Link it into the parent.
         */
        LIST_INSERT_HEAD(&parent->pcg_children, child, pcg_sibling);
        parent->pcg_nchildren++;

        return (child);
}

/*
 * Print one callgraph node.  The output format is:
 *
 * indentation %(parent's samples) #nsamples function@object
 */
static void
pmcstat_cgnode_print(struct pmcstat_cgnode *cg, int depth, uint32_t total)
{
        uint32_t n;
        const char *space;
        struct pmcstat_symbol *sym;
        struct pmcstat_cgnode **sortbuffer, **cgn, *pcg;

        space = " ";

        if (depth > 0)
                (void) fprintf(args.pa_graphfile, "%*s", depth, space);

        if (cg->pcg_count == total)
                (void) fprintf(args.pa_graphfile, "100.0%% ");
        else
                (void) fprintf(args.pa_graphfile, "%05.2f%% ",
                    100.0 * cg->pcg_count / total);

        n = fprintf(args.pa_graphfile, " [%u] ", cg->pcg_count);

        /* #samples is a 12 character wide field. */
        if (n < 12)
                (void) fprintf(args.pa_graphfile, "%*s", 12 - n, space);

        if (depth > 0)
                (void) fprintf(args.pa_graphfile, "%*s", depth, space);

        sym = pmcstat_symbol_search(cg->pcg_image, cg->pcg_func);
        if (sym)
                (void) fprintf(args.pa_graphfile, "%s",
                    pmcstat_string_unintern(sym->ps_name));
        else
                (void) fprintf(args.pa_graphfile, "%p",
                    (void *) (cg->pcg_image->pi_vaddr + cg->pcg_func));

        if (pmcstat_previous_filename_printed !=
            cg->pcg_image->pi_fullpath) {
                pmcstat_previous_filename_printed = cg->pcg_image->pi_fullpath;
                (void) fprintf(args.pa_graphfile, " @ %s\n",
                    pmcstat_string_unintern(
                    pmcstat_previous_filename_printed));
        } else
                (void) fprintf(args.pa_graphfile, "\n");

        if (cg->pcg_nchildren == 0)
                return;

        if ((sortbuffer = (struct pmcstat_cgnode **)
                malloc(sizeof(struct pmcstat_cgnode *) *
                    cg->pcg_nchildren)) == NULL)
                err(EX_OSERR, "ERROR: Cannot print callgraph");
        cgn = sortbuffer;

        LIST_FOREACH(pcg, &cg->pcg_children, pcg_sibling)
            *cgn++ = pcg;

        assert(cgn - sortbuffer == (int) cg->pcg_nchildren);

        qsort(sortbuffer, cg->pcg_nchildren, sizeof(struct pmcstat_cgnode *),
            pmcstat_cgnode_compare);

        for (cgn = sortbuffer, n = 0; n < cg->pcg_nchildren; n++, cgn++)
                pmcstat_cgnode_print(*cgn, depth+1, cg->pcg_count);

        free(sortbuffer);
}

/*
 * Record a callchain.
 */

void
pmcpl_cg_process(struct pmcstat_process *pp, struct pmcstat_pmcrecord *pmcr,
    uint32_t nsamples, uintfptr_t *cc, int usermode, uint32_t cpu)
{
        uintfptr_t pc, loadaddress;
        uint32_t n;
        struct pmcstat_image *image;
        struct pmcstat_pcmap *ppm;
        struct pmcstat_symbol *sym;
        struct pmcstat_cgnode *parent, *child;
        struct pmcstat_process *km;
        pmc_id_t pmcid;

        (void) cpu;

        /*
         * Find the callgraph node recorded in the global hash table
         * for this (pmcid, pc).
         */

        pc = cc[0];
        pmcid = pmcr->pr_pmcid;
        child = parent = pmcstat_cgnode_hash_lookup_pc(pp, pmcid, pc, usermode);
        if (parent == NULL) {
                pmcstat_stats.ps_callchain_dubious_frames++;
                pmcr->pr_dubious_frames++;
                return;
        }

        parent->pcg_count++;

        /*
         * For each return address in the call chain record, subject
         * to the maximum depth desired.
         * - Find the image associated with the sample.  Stop if there
         *   is no valid image at that address.
         * - Find the function that overlaps the return address.
         * - If found: use the start address of the function.
         *   If not found (say an object's symbol table is not present or
         *   is incomplete), round down to the gprof bucket granularity.
         * - Convert return virtual address to an offset in the image.
         * - Look for a child with the same {offset,image} tuple,
         *   inserting one if needed.
         * - Increment the count of occurrences of the child.
         */
        km = pmcstat_kernproc;

        for (n = 1; n < (uint32_t) args.pa_graphdepth && n < nsamples; n++,
            parent = child) {
                pc = cc[n];

                ppm = pmcstat_process_find_map(usermode ? pp : km, pc);
                if (ppm == NULL) {
                        /* Detect full frame capture (kernel + user). */
                        if (!usermode) {
                                ppm = pmcstat_process_find_map(pp, pc);
                                if (ppm != NULL)
                                        km = pp;
                        }
                }
                if (ppm == NULL)
                        continue;

                image = ppm->ppm_image;
                loadaddress = ppm->ppm_lowpc + image->pi_vaddr -
                    image->pi_start;
                pc -= loadaddress;

                if ((sym = pmcstat_symbol_search(image, pc)) != NULL)
                        pc = sym->ps_start;

                child = pmcstat_cgnode_find(parent, image, pc);
                child->pcg_count++;
        }
}

/*
 * Printing a callgraph for a PMC.
 */
static void
pmcstat_callgraph_print_for_pmcid(struct pmcstat_pmcrecord *pmcr)
{
        int n, nentries;
        uint32_t nsamples;
        pmc_id_t pmcid;
        struct pmcstat_cgnode **sortbuffer, **cgn;
        struct pmcstat_cgnode_hash *pch;

        /*
         * We pull out all callgraph nodes in the top-level hash table
         * with a matching PMC id.  We then sort these based on the
         * frequency of occurrence.  Each callgraph node is then
         * printed.
         */

        nsamples = 0;
        pmcid = pmcr->pr_pmcid;
        if ((sortbuffer = (struct pmcstat_cgnode **)
            malloc(sizeof(struct pmcstat_cgnode *) *
            pmcstat_cgnode_hash_count)) == NULL)
                err(EX_OSERR, "ERROR: Cannot sort callgraph");
        cgn = sortbuffer;

        for (n = 0; n < PMCSTAT_NHASH; n++)
                LIST_FOREACH(pch, &pmcstat_cgnode_hash[n], pch_next)
                    if (pch->pch_pmcid == pmcid) {
                            nsamples += pch->pch_cgnode->pcg_count;
                            *cgn++ = pch->pch_cgnode;
                    }

        nentries = cgn - sortbuffer;
        assert(nentries <= pmcstat_cgnode_hash_count);

        if (nentries == 0) {
                free(sortbuffer);
                return;
        }

        qsort(sortbuffer, nentries, sizeof(struct pmcstat_cgnode *),
            pmcstat_cgnode_compare);

        (void) fprintf(args.pa_graphfile,
            "@ %s [%u samples]\n\n",
            pmcstat_string_unintern(pmcr->pr_pmcname),
            nsamples);

        for (cgn = sortbuffer, n = 0; n < nentries; n++, cgn++) {
                pmcstat_previous_filename_printed = NULL;
                pmcstat_cgnode_print(*cgn, 0, nsamples);
                (void) fprintf(args.pa_graphfile, "\n");
        }

        free(sortbuffer);
}

/*
 * Print out callgraphs.
 */

static void
pmcstat_callgraph_print(void)
{
        struct pmcstat_pmcrecord *pmcr;

        LIST_FOREACH(pmcr, &pmcstat_pmcs, pr_next)
            pmcstat_callgraph_print_for_pmcid(pmcr);
}

static void
pmcstat_cgnode_topprint(struct pmcstat_cgnode *cg,
    int depth __unused, uint32_t nsamples)
{
        int v_attrs, vs_len, ns_len, width, len, n, nchildren;
        float v;
        char ns[30], vs[10];
        struct pmcstat_symbol *sym;
        struct pmcstat_cgnode **sortbuffer, **cgn, *pcg;

        /* Format value. */
        v = PMCPL_CG_COUNTP(cg);
        snprintf(vs, sizeof(vs), "%.1f", v);
        v_attrs = PMCSTAT_ATTRPERCENT(v);

        /* Format name. */
        sym = pmcstat_symbol_search(cg->pcg_image, cg->pcg_func);
        if (sym == NULL) {
                snprintf(ns, sizeof(ns), "%p",
                    (void *)(cg->pcg_image->pi_vaddr + cg->pcg_func));
        } else {
                switch (args.pa_flags & (FLAG_SKIP_TOP_FN_RES | FLAG_SHOW_OFFSET)) {
                case FLAG_SKIP_TOP_FN_RES | FLAG_SHOW_OFFSET:
                case FLAG_SKIP_TOP_FN_RES:
                        snprintf(ns, sizeof(ns), "%p",
                            (void *)(cg->pcg_image->pi_vaddr + cg->pcg_func));
                        break;
                case FLAG_SHOW_OFFSET:
                        snprintf(ns, sizeof(ns), "%s+%#0" PRIx64,
                            pmcstat_string_unintern(sym->ps_name),
                            cg->pcg_func - sym->ps_start);
                        break;
                default:
                        snprintf(ns, sizeof(ns), "%s",
                            pmcstat_string_unintern(sym->ps_name));
                        break;
                }
        }

        PMCSTAT_ATTRON(v_attrs);
        PMCSTAT_PRINTW("%5.5s", vs);
        PMCSTAT_ATTROFF(v_attrs);
        PMCSTAT_PRINTW(" %-10.10s %-30.30s",
            pmcstat_string_unintern(cg->pcg_image->pi_name),
            ns);

        nchildren = cg->pcg_nchildren;
        if (nchildren == 0) {
                PMCSTAT_PRINTW("\n");
                return;
        }

        width = pmcstat_displaywidth - 40;

        if ((sortbuffer = (struct pmcstat_cgnode **)
                malloc(sizeof(struct pmcstat_cgnode *) *
                    nchildren)) == NULL)
                err(EX_OSERR, "ERROR: Cannot print callgraph");
        cgn = sortbuffer;

        LIST_FOREACH(pcg, &cg->pcg_children, pcg_sibling)
            *cgn++ = pcg;

        assert(cgn - sortbuffer == (int)nchildren);

        qsort(sortbuffer, nchildren, sizeof(struct pmcstat_cgnode *),
            pmcstat_cgnode_compare);

        /* Count how many callers. */
        for (cgn = sortbuffer, n = 0; n < nchildren; n++, cgn++) {
                pcg = *cgn;

                v = PMCPL_CG_COUNTP(pcg);
                if (v < pmcstat_threshold)
                        break;
        }
        nchildren = n;

        for (cgn = sortbuffer, n = 0; n < nchildren; n++, cgn++) {
                pcg = *cgn;

                /* Format value. */
                if (nchildren > 1) {
                        v = PMCPL_CG_COUNTP(pcg);
                        vs_len = snprintf(vs, sizeof(vs), ":%.1f", v);
                        v_attrs = PMCSTAT_ATTRPERCENT(v);
                } else
                        vs_len = 0;

                /* Format name. */
                sym = pmcstat_symbol_search(pcg->pcg_image, pcg->pcg_func);
                if (sym != NULL) {
                        ns_len = snprintf(ns, sizeof(ns), "%s",
                            pmcstat_string_unintern(sym->ps_name));
                } else
                        ns_len = snprintf(ns, sizeof(ns), "%p",
                            (void *)pcg->pcg_func);

                len = ns_len + vs_len + 1;
                if (width - len < 0) {
                        PMCSTAT_PRINTW(" ...");
                        break;
                }
                width -= len;

                PMCSTAT_PRINTW(" %s", ns);
                if (nchildren > 1) {
                        PMCSTAT_ATTRON(v_attrs);
                        PMCSTAT_PRINTW("%s", vs);
                        PMCSTAT_ATTROFF(v_attrs);
                }
        }
        PMCSTAT_PRINTW("\n");
        free(sortbuffer);
}

/*
 * Top mode display.
 */

void
pmcpl_cg_topdisplay(void)
{
        int n, nentries;
        uint32_t nsamples;
        struct pmcstat_cgnode **sortbuffer, **cgn;
        struct pmcstat_cgnode_hash *pch;
        struct pmcstat_pmcrecord *pmcr;

        pmcr = pmcstat_pmcindex_to_pmcr(pmcstat_pmcinfilter);
        if (!pmcr)
                err(EX_SOFTWARE, "ERROR: invalid pmcindex");

        /*
         * We pull out all callgraph nodes in the top-level hash table
         * with a matching PMC index.  We then sort these based on the
         * frequency of occurrence.  Each callgraph node is then
         * printed.
         */

        nsamples = 0;

        if ((sortbuffer = (struct pmcstat_cgnode **)
            malloc(sizeof(struct pmcstat_cgnode *) *
            pmcstat_cgnode_hash_count)) == NULL)
                err(EX_OSERR, "ERROR: Cannot sort callgraph");
        cgn = sortbuffer;

        for (n = 0; n < PMCSTAT_NHASH; n++)
                LIST_FOREACH(pch, &pmcstat_cgnode_hash[n], pch_next)
                    if (pmcr == NULL || pch->pch_pmcid == pmcr->pr_pmcid) {
                            nsamples += pch->pch_cgnode->pcg_count;
                            *cgn++ = pch->pch_cgnode;
                    }

        nentries = cgn - sortbuffer;
        assert(nentries <= pmcstat_cgnode_hash_count);

        if (nentries == 0) {
                free(sortbuffer);
                return;
        }

        qsort(sortbuffer, nentries, sizeof(struct pmcstat_cgnode *),
            pmcstat_cgnode_compare);

        PMCSTAT_PRINTW("%5.5s %-10.10s %-30.30s %s\n",
            "%SAMP", "IMAGE", "FUNCTION", "CALLERS");

        nentries = min(pmcstat_displayheight - 2, nentries);

        for (cgn = sortbuffer, n = 0; n < nentries; n++, cgn++) {
                if (PMCPL_CG_COUNTP(*cgn) < pmcstat_threshold)
                        break;
                pmcstat_cgnode_topprint(*cgn, 0, nsamples);
        }

        free(sortbuffer);
}

/*
 * Handle top mode keypress.
 */

int
pmcpl_cg_topkeypress(int c, void *arg)
{
        WINDOW *w;

        w = (WINDOW *)arg;

        (void) c; (void) w;

        return 0;
}

int
pmcpl_cg_init(void)
{
        int i;

        pmcstat_cgnode_hash_count = 0;
        pmcstat_previous_filename_printed = NULL;

        for (i = 0; i < PMCSTAT_NHASH; i++) {
                LIST_INIT(&pmcstat_cgnode_hash[i]);
        }

        return (0);
}

void
pmcpl_cg_shutdown(FILE *mf)
{
        int i;
        struct pmcstat_cgnode_hash *pch, *pchtmp;

        (void) mf;

        if (args.pa_flags & FLAG_DO_CALLGRAPHS)
                pmcstat_callgraph_print();

        /*
         * Free memory.
         */
        for (i = 0; i < PMCSTAT_NHASH; i++) {
                LIST_FOREACH_SAFE(pch, &pmcstat_cgnode_hash[i], pch_next,
                    pchtmp) {
                        pmcstat_cgnode_free(pch->pch_cgnode);
                        LIST_REMOVE(pch, pch_next);
                        free(pch);
                }
        }
}