/src/git/line-log.c

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#include "git-compat-util.h"
#include "diffcore.h"
#include "line-range.h"
#include "hex.h"
#include "tag.h"
#include "tree.h"
#include "diff.h"
#include "commit.h"
#include "decorate.h"
#include "repository.h"
#include "revision.h"
#include "xdiff-interface.h"
#include "strbuf.h"
#include "log-tree.h"
#include "line-log.h"
#include "setup.h"
#include "strvec.h"
#include "bloom.h"
#include "tree-walk.h"

static void range_set_grow(struct range_set *rs, size_t extra)
{
  ALLOC_GROW(rs->ranges, rs->nr + extra, rs->alloc);
}

/* Either initialization would be fine */
#define RANGE_SET_INIT {0}

void range_set_init(struct range_set *rs, size_t prealloc)
{
  rs->alloc = rs->nr = 0;
  rs->ranges = NULL;
  if (prealloc)
    range_set_grow(rs, prealloc);
}

void range_set_release(struct range_set *rs)
{
  FREE_AND_NULL(rs->ranges);
  rs->alloc = rs->nr = 0;
}

/* dst must be uninitialized! */
static void range_set_copy(struct range_set *dst, struct range_set *src)
{
  range_set_init(dst, src->nr);
  COPY_ARRAY(dst->ranges, src->ranges, src->nr);
  dst->nr = src->nr;
}

static void range_set_move(struct range_set *dst, struct range_set *src)
{
  range_set_release(dst);
  dst->ranges = src->ranges;
  dst->nr = src->nr;
  dst->alloc = src->alloc;
  src->ranges = NULL;
  src->alloc = src->nr = 0;
}

/* tack on a _new_ range _at the end_ */
void range_set_append_unsafe(struct range_set *rs, long a, long b)
{
  assert(a <= b);
  range_set_grow(rs, 1);
  rs->ranges[rs->nr].start = a;
  rs->ranges[rs->nr].end = b;
  rs->nr++;
}

void range_set_append(struct range_set *rs, long a, long b)
{
  assert(rs->nr == 0 || rs->ranges[rs->nr-1].end <= a);
  range_set_append_unsafe(rs, a, b);
}

static int range_cmp(const void *_r, const void *_s)
{
  const struct range *r = _r;
  const struct range *s = _s;

  /* this could be simply 'return r.start-s.start', but for the types */
  if (r->start == s->start)
    return 0;
  if (r->start < s->start)
    return -1;
  return 1;
}

/*
 * Check that the ranges are non-empty, sorted and non-overlapping
 */
static void range_set_check_invariants(struct range_set *rs)
{
  unsigned int i;

  if (!rs)
    return;

  if (rs->nr)
    assert(rs->ranges[0].start < rs->ranges[0].end);

  for (i = 1; i < rs->nr; i++) {
    assert(rs->ranges[i-1].end < rs->ranges[i].start);
    assert(rs->ranges[i].start < rs->ranges[i].end);
  }
}

/*
 * In-place pass of sorting and merging the ranges in the range set,
 * to establish the invariants when we get the ranges from the user
 */
void sort_and_merge_range_set(struct range_set *rs)
{
  unsigned int i;
  unsigned int o = 0; /* output cursor */

  QSORT(rs->ranges, rs->nr, range_cmp);

  for (i = 0; i < rs->nr; i++) {
    if (rs->ranges[i].start == rs->ranges[i].end)
      continue;
    if (o > 0 && rs->ranges[i].start <= rs->ranges[o-1].end) {
      if (rs->ranges[o-1].end < rs->ranges[i].end)
        rs->ranges[o-1].end = rs->ranges[i].end;
    } else {
      rs->ranges[o].start = rs->ranges[i].start;
      rs->ranges[o].end = rs->ranges[i].end;
      o++;
    }
  }
  assert(o <= rs->nr);
  rs->nr = o;

  range_set_check_invariants(rs);
}

/*
 * Union of range sets (i.e., sets of line numbers).  Used to merge
 * them when searches meet at a common ancestor.
 *
 * This is also where the ranges are consolidated into canonical form:
 * overlapping and adjacent ranges are merged, and empty ranges are
 * removed.
 */
static void range_set_union(struct range_set *out,
           struct range_set *a, struct range_set *b)
{
  unsigned int i = 0, j = 0;
  struct range *ra = a->ranges;
  struct range *rb = b->ranges;
  /* cannot make an alias of out->ranges: it may change during grow */

  assert(out->nr == 0);
  while (i < a->nr || j < b->nr) {
    struct range *new_range;
    if (i < a->nr && j < b->nr) {
      if (ra[i].start < rb[j].start)
        new_range = &ra[i++];
      else if (ra[i].start > rb[j].start)
        new_range = &rb[j++];
      else if (ra[i].end < rb[j].end)
        new_range = &ra[i++];
      else
        new_range = &rb[j++];
    } else if (i < a->nr)      /* b exhausted */
      new_range = &ra[i++];
    else                       /* a exhausted */
      new_range = &rb[j++];
    if (new_range->start == new_range->end)
      ; /* empty range */
    else if (!out->nr || out->ranges[out->nr-1].end < new_range->start) {
      range_set_grow(out, 1);
      out->ranges[out->nr].start = new_range->start;
      out->ranges[out->nr].end = new_range->end;
      out->nr++;
    } else if (out->ranges[out->nr-1].end < new_range->end) {
      out->ranges[out->nr-1].end = new_range->end;
    }
  }
}

/*
 * Difference of range sets (out = a \ b).  Pass the "interesting"
 * ranges as 'a' and the target side of the diff as 'b': it removes
 * the ranges for which the commit is responsible.
 */
static void range_set_difference(struct range_set *out,
          struct range_set *a, struct range_set *b)
{
  unsigned int i, j =  0;
  for (i = 0; i < a->nr; i++) {
    long start = a->ranges[i].start;
    long end = a->ranges[i].end;
    while (start < end) {
      while (j < b->nr && start >= b->ranges[j].end)
        /*
         * a:         |-------
         * b: ------|
         */
        j++;
      if (j >= b->nr || end < b->ranges[j].start) {
        /*
         * b exhausted, or
         * a:  ----|
         * b:         |----
         */
        range_set_append(out, start, end);
        break;
      }
      if (start >= b->ranges[j].start) {
        /*
         * a:     |--????
         * b: |------|
         */
        start = b->ranges[j].end;
      } else if (end > b->ranges[j].start) {
        /*
         * a: |-----|
         * b:    |--?????
         */
        if (start < b->ranges[j].start)
          range_set_append(out, start, b->ranges[j].start);
        start = b->ranges[j].end;
      }
    }
  }
}

static void diff_ranges_init(struct diff_ranges *diff)
{
  range_set_init(&diff->parent, 0);
  range_set_init(&diff->target, 0);
}

static void diff_ranges_release(struct diff_ranges *diff)
{
  range_set_release(&diff->parent);
  range_set_release(&diff->target);
}

static void line_log_data_init(struct line_log_data *r)
{
  memset(r, 0, sizeof(struct line_log_data));
  range_set_init(&r->ranges, 0);
}

static void line_log_data_clear(struct line_log_data *r)
{
  range_set_release(&r->ranges);
  if (r->pair)
    diff_free_filepair(r->pair);
}

static void free_line_log_data(struct line_log_data *r)
{
  while (r) {
    struct line_log_data *next = r->next;
    line_log_data_clear(r);
    free(r);
    r = next;
  }
}

static struct line_log_data *
search_line_log_data(struct line_log_data *list, const char *path,
         struct line_log_data **insertion_point)
{
  struct line_log_data *p = list;
  if (insertion_point)
    *insertion_point = NULL;
  while (p) {
    int cmp = strcmp(p->path, path);
    if (!cmp)
      return p;
    if (insertion_point && cmp < 0)
      *insertion_point = p;
    p = p->next;
  }
  return NULL;
}

/*
 * Note: takes ownership of 'path', which happens to be what the only
 * caller needs.
 */
static void line_log_data_insert(struct line_log_data **list,
         char *path,
         long begin, long end)
{
  struct line_log_data *ip;
  struct line_log_data *p = search_line_log_data(*list, path, &ip);

  if (p) {
    range_set_append_unsafe(&p->ranges, begin, end);
    free(path);
    return;
  }

  CALLOC_ARRAY(p, 1);
  p->path = path;
  range_set_append(&p->ranges, begin, end);
  if (ip) {
    p->next = ip->next;
    ip->next = p;
  } else {
    p->next = *list;
    *list = p;
  }
}

struct collect_diff_cbdata {
  struct diff_ranges *diff;
};

static int collect_diff_cb(long start_a, long count_a,
         long start_b, long count_b,
         void *data)
{
  struct collect_diff_cbdata *d = data;

  if (count_a >= 0)
    range_set_append(&d->diff->parent, start_a, start_a + count_a);
  if (count_b >= 0)
    range_set_append(&d->diff->target, start_b, start_b + count_b);

  return 0;
}

static int collect_diff(mmfile_t *parent, mmfile_t *target, struct diff_ranges *out)
{
  struct collect_diff_cbdata cbdata = {NULL};
  xpparam_t xpp;
  xdemitconf_t xecfg;
  xdemitcb_t ecb;

  memset(&xpp, 0, sizeof(xpp));
  memset(&xecfg, 0, sizeof(xecfg));
  xecfg.ctxlen = xecfg.interhunkctxlen = 0;

  cbdata.diff = out;
  xecfg.hunk_func = collect_diff_cb;
  memset(&ecb, 0, sizeof(ecb));
  ecb.priv = &cbdata;
  return xdi_diff(parent, target, &xpp, &xecfg, &ecb);
}

/*
 * These are handy for debugging.  Removing them with #if 0 silences
 * the "unused function" warning.
 */
#if 0
static void dump_range_set(struct range_set *rs, const char *desc)
{
  int i;
  printf("range set %s (%d items):\n", desc, rs->nr);
  for (i = 0; i < rs->nr; i++)
    printf("\t[%ld,%ld]\n", rs->ranges[i].start, rs->ranges[i].end);
}

static void dump_line_log_data(struct line_log_data *r)
{
  char buf[4096];
  while (r) {
    snprintf(buf, 4096, "file %s\n", r->path);
    dump_range_set(&r->ranges, buf);
    r = r->next;
  }
}

static void dump_diff_ranges(struct diff_ranges *diff, const char *desc)
{
  int i;
  assert(diff->parent.nr == diff->target.nr);
  printf("diff ranges %s (%d items):\n", desc, diff->parent.nr);
  printf("\tparent\ttarget\n");
  for (i = 0; i < diff->parent.nr; i++) {
    printf("\t[%ld,%ld]\t[%ld,%ld]\n",
           diff->parent.ranges[i].start,
           diff->parent.ranges[i].end,
           diff->target.ranges[i].start,
           diff->target.ranges[i].end);
  }
}
#endif


static int ranges_overlap(struct range *a, struct range *b)
{
  return !(a->end <= b->start || b->end <= a->start);
}

/*
 * Given a diff and the set of interesting ranges, determine all hunks
 * of the diff which touch (overlap) at least one of the interesting
 * ranges in the target.
 */
static void diff_ranges_filter_touched(struct diff_ranges *out,
               struct diff_ranges *diff,
               struct range_set *rs)
{
  unsigned int i, j = 0;

  assert(out->target.nr == 0);

  for (i = 0; i < diff->target.nr; i++) {
    while (diff->target.ranges[i].start > rs->ranges[j].end) {
      j++;
      if (j == rs->nr)
        return;
    }
    if (ranges_overlap(&diff->target.ranges[i], &rs->ranges[j])) {
      range_set_append(&out->parent,
           diff->parent.ranges[i].start,
           diff->parent.ranges[i].end);
      range_set_append(&out->target,
           diff->target.ranges[i].start,
           diff->target.ranges[i].end);
    }
  }
}

/*
 * Adjust the line counts in 'rs' to account for the lines
 * added/removed in the diff.
 */
static void range_set_shift_diff(struct range_set *out,
         struct range_set *rs,
         struct diff_ranges *diff)
{
  unsigned int i, j = 0;
  long offset = 0;
  struct range *src = rs->ranges;
  struct range *target = diff->target.ranges;
  struct range *parent = diff->parent.ranges;

  for (i = 0; i < rs->nr; i++) {
    while (j < diff->target.nr && src[i].start >= target[j].start) {
      offset += (parent[j].end-parent[j].start)
        - (target[j].end-target[j].start);
      j++;
    }
    range_set_append(out, src[i].start+offset, src[i].end+offset);
  }
}

/*
 * Given a diff and the set of interesting ranges, map the ranges
 * across the diff.  That is: observe that the target commit takes
 * blame for all the + (target-side) ranges.  So for every pair of
 * ranges in the diff that was touched, we remove the latter and add
 * its parent side.
 */
static void range_set_map_across_diff(struct range_set *out,
              struct range_set *rs,
              struct diff_ranges *diff,
              struct diff_ranges **touched_out)
{
  struct diff_ranges *touched = xmalloc(sizeof(*touched));
  struct range_set tmp1 = RANGE_SET_INIT;
  struct range_set tmp2 = RANGE_SET_INIT;

  diff_ranges_init(touched);
  diff_ranges_filter_touched(touched, diff, rs);
  range_set_difference(&tmp1, rs, &touched->target);
  range_set_shift_diff(&tmp2, &tmp1, diff);
  range_set_union(out, &tmp2, &touched->parent);
  range_set_release(&tmp1);
  range_set_release(&tmp2);

  *touched_out = touched;
}

static struct commit *check_single_commit(struct rev_info *revs)
{
  struct object *commit = NULL;
  int found = -1;
  int i;

  for (i = 0; i < revs->pending.nr; i++) {
    struct object *obj = revs->pending.objects[i].item;
    if (obj->flags & UNINTERESTING)
      continue;
    obj = deref_tag(revs->repo, obj, NULL, 0);
    if (!obj || obj->type != OBJ_COMMIT)
      die("Non commit %s?", revs->pending.objects[i].name);
    if (commit)
      die("More than one commit to dig from: %s and %s?",
          revs->pending.objects[i].name,
          revs->pending.objects[found].name);
    commit = obj;
    found = i;
  }

  if (!commit)
    die("No commit specified?");

  return (struct commit *) commit;
}

static void fill_blob_sha1(struct repository *r, struct commit *commit,
         struct diff_filespec *spec)
{
  unsigned short mode;
  struct object_id oid;

  if (get_tree_entry(r, &commit->object.oid, spec->path, &oid, &mode))
    die("There is no path %s in the commit", spec->path);
  fill_filespec(spec, &oid, 1, mode);

  return;
}

static void fill_line_ends(struct repository *r,
         struct diff_filespec *spec,
         long *lines,
         unsigned long **line_ends)
{
  int num = 0, size = 50;
  long cur = 0;
  unsigned long *ends = NULL;
  char *data = NULL;

  if (diff_populate_filespec(r, spec, NULL))
    die("Cannot read blob %s", oid_to_hex(&spec->oid));

  ALLOC_ARRAY(ends, size);
  ends[cur++] = 0;
  data = spec->data;
  while (num < spec->size) {
    if (data[num] == '\n' || num == spec->size - 1) {
      ALLOC_GROW(ends, (cur + 1), size);
      ends[cur++] = num;
    }
    num++;
  }

  /* shrink the array to fit the elements */
  REALLOC_ARRAY(ends, cur);
  *lines = cur-1;
  *line_ends = ends;
}

struct nth_line_cb {
  struct diff_filespec *spec;
  long lines;
  unsigned long *line_ends;
};

static const char *nth_line(void *data, long line)
{
  struct nth_line_cb *d = data;
  assert(d && line <= d->lines);
  assert(d->spec && d->spec->data);

  if (line == 0)
    return (char *)d->spec->data;
  else
    return (char *)d->spec->data + d->line_ends[line] + 1;
}

static struct line_log_data *
parse_lines(struct repository *r, struct commit *commit,
      const char *prefix, struct string_list *args)
{
  long lines = 0;
  unsigned long *ends = NULL;
  struct nth_line_cb cb_data;
  struct string_list_item *item;
  struct line_log_data *ranges = NULL;
  struct line_log_data *p;

  for_each_string_list_item(item, args) {
    const char *name_part, *range_part;
    char *full_name;
    struct diff_filespec *spec;
    long begin = 0, end = 0;
    long anchor;

    name_part = skip_range_arg(item->string, r->index);
    if (!name_part || *name_part != ':' || !name_part[1])
      die("-L argument not 'start,end:file' or ':funcname:file': %s",
          item->string);
    range_part = xstrndup(item->string, name_part - item->string);
    name_part++;

    full_name = prefix_path(prefix, prefix ? strlen(prefix) : 0,
          name_part);

    spec = alloc_filespec(full_name);
    fill_blob_sha1(r, commit, spec);
    fill_line_ends(r, spec, &lines, &ends);
    cb_data.spec = spec;
    cb_data.lines = lines;
    cb_data.line_ends = ends;

    p = search_line_log_data(ranges, full_name, NULL);
    if (p && p->ranges.nr)
      anchor = p->ranges.ranges[p->ranges.nr - 1].end + 1;
    else
      anchor = 1;

    if (parse_range_arg(range_part, nth_line, &cb_data,
            lines, anchor, &begin, &end,
            full_name, r->index))
      die("malformed -L argument '%s'", range_part);
    if ((!lines && (begin || end)) || lines < begin)
      die("file %s has only %lu lines", name_part, lines);
    if (begin < 1)
      begin = 1;
    if (end < 1 || lines < end)
      end = lines;
    begin--;
    line_log_data_insert(&ranges, full_name, begin, end);

    free_filespec(spec);
    FREE_AND_NULL(ends);
  }

  for (p = ranges; p; p = p->next)
    sort_and_merge_range_set(&p->ranges);

  return ranges;
}

static struct line_log_data *line_log_data_copy_one(struct line_log_data *r)
{
  struct line_log_data *ret = xmalloc(sizeof(*ret));

  assert(r);
  line_log_data_init(ret);
  range_set_copy(&ret->ranges, &r->ranges);

  ret->path = xstrdup(r->path);

  return ret;
}

static struct line_log_data *
line_log_data_copy(struct line_log_data *r)
{
  struct line_log_data *ret = NULL;
  struct line_log_data *tmp = NULL, *prev = NULL;

  assert(r);
  ret = tmp = prev = line_log_data_copy_one(r);
  r = r->next;
  while (r) {
    tmp = line_log_data_copy_one(r);
    prev->next = tmp;
    prev = tmp;
    r = r->next;
  }

  return ret;
}

/* merge two range sets across files */
static struct line_log_data *line_log_data_merge(struct line_log_data *a,
             struct line_log_data *b)
{
  struct line_log_data *head = NULL, **pp = &head;

  while (a || b) {
    struct line_log_data *src;
    struct line_log_data *src2 = NULL;
    struct line_log_data *d;
    int cmp;
    if (!a)
      cmp = 1;
    else if (!b)
      cmp = -1;
    else
      cmp = strcmp(a->path, b->path);
    if (cmp < 0) {
      src = a;
      a = a->next;
    } else if (cmp == 0) {
      src = a;
      a = a->next;
      src2 = b;
      b = b->next;
    } else {
      src = b;
      b = b->next;
    }
    d = xmalloc(sizeof(struct line_log_data));
    line_log_data_init(d);
    d->path = xstrdup(src->path);
    *pp = d;
    pp = &d->next;
    if (src2)
      range_set_union(&d->ranges, &src->ranges, &src2->ranges);
    else
      range_set_copy(&d->ranges, &src->ranges);
  }

  return head;
}

static void add_line_range(struct rev_info *revs, struct commit *commit,
         struct line_log_data *range)
{
  struct line_log_data *old_line = NULL;
  struct line_log_data *new_line = NULL;

  old_line = lookup_decoration(&revs->line_log_data, &commit->object);
  if (old_line && range) {
    new_line = line_log_data_merge(old_line, range);
    free_line_log_data(old_line);
  } else if (range)
    new_line = line_log_data_copy(range);

  if (new_line)
    add_decoration(&revs->line_log_data, &commit->object, new_line);
}

static void clear_commit_line_range(struct rev_info *revs, struct commit *commit)
{
  struct line_log_data *r;
  r = lookup_decoration(&revs->line_log_data, &commit->object);
  if (!r)
    return;
  free_line_log_data(r);
  add_decoration(&revs->line_log_data, &commit->object, NULL);
}

static struct line_log_data *lookup_line_range(struct rev_info *revs,
                 struct commit *commit)
{
  struct line_log_data *ret = NULL;
  struct line_log_data *d;

  ret = lookup_decoration(&revs->line_log_data, &commit->object);

  for (d = ret; d; d = d->next)
    range_set_check_invariants(&d->ranges);

  return ret;
}

static int same_paths_in_pathspec_and_range(struct pathspec *pathspec,
              struct line_log_data *range)
{
  int i;
  struct line_log_data *r;

  for (i = 0, r = range; i < pathspec->nr && r; i++, r = r->next)
    if (strcmp(pathspec->items[i].match, r->path))
      return 0;
  if (i < pathspec->nr || r)
    /* different number of pathspec items and ranges */
    return 0;

  return 1;
}

static void parse_pathspec_from_ranges(struct pathspec *pathspec,
               struct line_log_data *range)
{
  struct line_log_data *r;
  struct strvec array = STRVEC_INIT;
  const char **paths;

  for (r = range; r; r = r->next)
    strvec_push(&array, r->path);
  paths = strvec_detach(&array);

  parse_pathspec(pathspec, 0, PATHSPEC_PREFER_FULL, "", paths);
  /* strings are now owned by pathspec */
  free(paths);
}

void line_log_init(struct rev_info *rev, const char *prefix, struct string_list *args)
{
  struct commit *commit = NULL;
  struct line_log_data *range;

  commit = check_single_commit(rev);
  range = parse_lines(rev->diffopt.repo, commit, prefix, args);
  add_line_range(rev, commit, range);

  parse_pathspec_from_ranges(&rev->diffopt.pathspec, range);
}

static void move_diff_queue(struct diff_queue_struct *dst,
          struct diff_queue_struct *src)
{
  assert(src != dst);
  memcpy(dst, src, sizeof(struct diff_queue_struct));
  DIFF_QUEUE_CLEAR(src);
}

static void filter_diffs_for_paths(struct line_log_data *range, int keep_deletions)
{
  int i;
  struct diff_queue_struct outq;
  DIFF_QUEUE_CLEAR(&outq);

  for (i = 0; i < diff_queued_diff.nr; i++) {
    struct diff_filepair *p = diff_queued_diff.queue[i];
    struct line_log_data *rg = NULL;

    if (!DIFF_FILE_VALID(p->two)) {
      if (keep_deletions)
        diff_q(&outq, p);
      else
        diff_free_filepair(p);
      continue;
    }
    for (rg = range; rg; rg = rg->next) {
      if (!strcmp(rg->path, p->two->path))
        break;
    }
    if (rg)
      diff_q(&outq, p);
    else
      diff_free_filepair(p);
  }
  free(diff_queued_diff.queue);
  diff_queued_diff = outq;
}

static inline int diff_might_be_rename(void)
{
  int i;
  for (i = 0; i < diff_queued_diff.nr; i++)
    if (!DIFF_FILE_VALID(diff_queued_diff.queue[i]->one)) {
      /* fprintf(stderr, "diff_might_be_rename found creation of: %s\n", */
      /*  diff_queued_diff.queue[i]->two->path); */
      return 1;
    }
  return 0;
}

static void queue_diffs(struct line_log_data *range,
      struct diff_options *opt,
      struct diff_queue_struct *queue,
      struct commit *commit, struct commit *parent)
{
  struct object_id *tree_oid, *parent_tree_oid;

  assert(commit);

  tree_oid = get_commit_tree_oid(commit);
  parent_tree_oid = parent ? get_commit_tree_oid(parent) : NULL;

  if (opt->detect_rename &&
      !same_paths_in_pathspec_and_range(&opt->pathspec, range)) {
    clear_pathspec(&opt->pathspec);
    parse_pathspec_from_ranges(&opt->pathspec, range);
  }
  DIFF_QUEUE_CLEAR(&diff_queued_diff);
  diff_tree_oid(parent_tree_oid, tree_oid, "", opt);
  if (opt->detect_rename && diff_might_be_rename()) {
    /* must look at the full tree diff to detect renames */
    clear_pathspec(&opt->pathspec);
    DIFF_QUEUE_CLEAR(&diff_queued_diff);

    diff_tree_oid(parent_tree_oid, tree_oid, "", opt);

    filter_diffs_for_paths(range, 1);
    diffcore_std(opt);
    filter_diffs_for_paths(range, 0);
  }
  move_diff_queue(queue, &diff_queued_diff);
}

static char *get_nth_line(long line, unsigned long *ends, void *data)
{
  if (line == 0)
    return (char *)data;
  else
    return (char *)data + ends[line] + 1;
}

static void print_line(const char *prefix, char first,
           long line, unsigned long *ends, void *data,
           const char *color, const char *reset, FILE *file)
{
  char *begin = get_nth_line(line, ends, data);
  char *end = get_nth_line(line+1, ends, data);
  int had_nl = 0;

  if (end > begin && end[-1] == '\n') {
    end--;
    had_nl = 1;
  }

  fputs(prefix, file);
  fputs(color, file);
  putc(first, file);
  fwrite(begin, 1, end-begin, file);
  fputs(reset, file);
  putc('\n', file);
  if (!had_nl)
    fputs("\\ No newline at end of file\n", file);
}

static char *output_prefix(struct diff_options *opt)
{
  if (opt->output_prefix) {
    struct strbuf *sb = opt->output_prefix(opt, opt->output_prefix_data);
    return sb->buf;
  } else {
    return xstrdup("");
  }
}

static void dump_diff_hacky_one(struct rev_info *rev, struct line_log_data *range)
{
  unsigned int i, j = 0;
  long p_lines, t_lines;
  unsigned long *p_ends = NULL, *t_ends = NULL;
  struct diff_filepair *pair = range->pair;
  struct diff_ranges *diff = &range->diff;

  struct diff_options *opt = &rev->diffopt;
  char *prefix = output_prefix(opt);
  const char *c_reset = diff_get_color(opt->use_color, DIFF_RESET);
  const char *c_frag = diff_get_color(opt->use_color, DIFF_FRAGINFO);
  const char *c_meta = diff_get_color(opt->use_color, DIFF_METAINFO);
  const char *c_old = diff_get_color(opt->use_color, DIFF_FILE_OLD);
  const char *c_new = diff_get_color(opt->use_color, DIFF_FILE_NEW);
  const char *c_context = diff_get_color(opt->use_color, DIFF_CONTEXT);

  if (!pair || !diff)
    goto out;

  if (pair->one->oid_valid)
    fill_line_ends(rev->diffopt.repo, pair->one, &p_lines, &p_ends);
  fill_line_ends(rev->diffopt.repo, pair->two, &t_lines, &t_ends);

  fprintf(opt->file, "%s%sdiff --git a/%s b/%s%s\n", prefix, c_meta, pair->one->path, pair->two->path, c_reset);
  fprintf(opt->file, "%s%s--- %s%s%s\n", prefix, c_meta,
         pair->one->oid_valid ? "a/" : "",
         pair->one->oid_valid ? pair->one->path : "/dev/null",
         c_reset);
  fprintf(opt->file, "%s%s+++ b/%s%s\n", prefix, c_meta, pair->two->path, c_reset);
  for (i = 0; i < range->ranges.nr; i++) {
    long p_start, p_end;
    long t_start = range->ranges.ranges[i].start;
    long t_end = range->ranges.ranges[i].end;
    long t_cur = t_start;
    unsigned int j_last;

    while (j < diff->target.nr && diff->target.ranges[j].end < t_start)
      j++;
    if (j == diff->target.nr || diff->target.ranges[j].start > t_end)
      continue;

    /* Scan ahead to determine the last diff that falls in this range */
    j_last = j;
    while (j_last < diff->target.nr && diff->target.ranges[j_last].start < t_end)
      j_last++;
    if (j_last > j)
      j_last--;

    /*
     * Compute parent hunk headers: we know that the diff
     * has the correct line numbers (but not all hunks).
     * So it suffices to shift the start/end according to
     * the line numbers of the first/last hunk(s) that
     * fall in this range.
     */
    if (t_start < diff->target.ranges[j].start)
      p_start = diff->parent.ranges[j].start - (diff->target.ranges[j].start-t_start);
    else
      p_start = diff->parent.ranges[j].start;
    if (t_end > diff->target.ranges[j_last].end)
      p_end = diff->parent.ranges[j_last].end + (t_end-diff->target.ranges[j_last].end);
    else
      p_end = diff->parent.ranges[j_last].end;

    if (!p_start && !p_end) {
      p_start = -1;
      p_end = -1;
    }

    /* Now output a diff hunk for this range */
    fprintf(opt->file, "%s%s@@ -%ld,%ld +%ld,%ld @@%s\n",
           prefix, c_frag,
           p_start+1, p_end-p_start, t_start+1, t_end-t_start,
           c_reset);
    while (j < diff->target.nr && diff->target.ranges[j].start < t_end) {
      int k;
      for (; t_cur < diff->target.ranges[j].start; t_cur++)
        print_line(prefix, ' ', t_cur, t_ends, pair->two->data,
             c_context, c_reset, opt->file);
      for (k = diff->parent.ranges[j].start; k < diff->parent.ranges[j].end; k++)
        print_line(prefix, '-', k, p_ends, pair->one->data,
             c_old, c_reset, opt->file);
      for (; t_cur < diff->target.ranges[j].end && t_cur < t_end; t_cur++)
        print_line(prefix, '+', t_cur, t_ends, pair->two->data,
             c_new, c_reset, opt->file);
      j++;
    }
    for (; t_cur < t_end; t_cur++)
      print_line(prefix, ' ', t_cur, t_ends, pair->two->data,
           c_context, c_reset, opt->file);
  }

out:
  free(p_ends);
  free(t_ends);
  free(prefix);
}

/*
 * NEEDSWORK: manually building a diff here is not the Right
 * Thing(tm).  log -L should be built into the diff pipeline.
 */
static void dump_diff_hacky(struct rev_info *rev, struct line_log_data *range)
{
  char *prefix = output_prefix(&rev->diffopt);

  fprintf(rev->diffopt.file, "%s\n", prefix);
  free(prefix);

  while (range) {
    dump_diff_hacky_one(rev, range);
    range = range->next;
  }
}

/*
 * Unlike most other functions, this destructively operates on
 * 'range'.
 */
static int process_diff_filepair(struct rev_info *rev,
         struct diff_filepair *pair,
         struct line_log_data *range,
         struct diff_ranges **diff_out)
{
  struct line_log_data *rg = range;
  struct range_set tmp;
  struct diff_ranges diff;
  mmfile_t file_parent, file_target;
  char *parent_data_to_free = NULL;

  assert(pair->two->path);
  while (rg) {
    assert(rg->path);
    if (!strcmp(rg->path, pair->two->path))
      break;
    rg = rg->next;
  }

  if (!rg)
    return 0;
  if (rg->ranges.nr == 0)
    return 0;

  assert(pair->two->oid_valid);
  diff_populate_filespec(rev->diffopt.repo, pair->two, NULL);
  file_target.ptr = pair->two->data;
  file_target.size = pair->two->size;

  if (pair->one->oid_valid) {
    diff_populate_filespec(rev->diffopt.repo, pair->one, NULL);
    file_parent.ptr = pair->one->data;
    file_parent.size = pair->one->size;
  } else {
    file_parent.ptr = parent_data_to_free = xstrdup("");
    file_parent.size = 0;
  }

  diff_ranges_init(&diff);
  if (collect_diff(&file_parent, &file_target, &diff))
    die("unable to generate diff for %s", pair->one->path);

  /* NEEDSWORK should apply some heuristics to prevent mismatches */
  free(rg->path);
  rg->path = xstrdup(pair->one->path);

  range_set_init(&tmp, 0);
  range_set_map_across_diff(&tmp, &rg->ranges, &diff, diff_out);
  range_set_release(&rg->ranges);
  range_set_move(&rg->ranges, &tmp);

  diff_ranges_release(&diff);

  free(parent_data_to_free);
  return ((*diff_out)->parent.nr > 0);
}

static struct diff_filepair *diff_filepair_dup(struct diff_filepair *pair)
{
  struct diff_filepair *new_filepair = xmalloc(sizeof(struct diff_filepair));
  new_filepair->one = pair->one;
  new_filepair->two = pair->two;
  new_filepair->one->count++;
  new_filepair->two->count++;
  return new_filepair;
}

static void free_diffqueues(int n, struct diff_queue_struct *dq)
{
  for (int i = 0; i < n; i++)
    diff_free_queue(&dq[i]);
  free(dq);
}

static int process_all_files(struct line_log_data **range_out,
           struct rev_info *rev,
           struct diff_queue_struct *queue,
           struct line_log_data *range)
{
  int i, changed = 0;

  *range_out = line_log_data_copy(range);

  for (i = 0; i < queue->nr; i++) {
    struct diff_ranges *pairdiff = NULL;
    struct diff_filepair *pair = queue->queue[i];
    if (process_diff_filepair(rev, pair, *range_out, &pairdiff)) {
      /*
       * Store away the diff for later output.  We
       * tuck it in the ranges we got as _input_,
       * since that's the commit that caused the
       * diff.
       *
       * NEEDSWORK not enough when we get around to
       * doing something interesting with merges;
       * currently each invocation on a merge parent
       * trashes the previous one's diff.
       *
       * NEEDSWORK tramples over data structures not owned here
       */
      struct line_log_data *rg = range;
      changed++;
      while (rg && strcmp(rg->path, pair->two->path))
        rg = rg->next;
      assert(rg);
      rg->pair = diff_filepair_dup(queue->queue[i]);
      memcpy(&rg->diff, pairdiff, sizeof(struct diff_ranges));
    }
    free(pairdiff);
  }

  return changed;
}

int line_log_print(struct rev_info *rev, struct commit *commit)
{

  show_log(rev);
  if (!(rev->diffopt.output_format & DIFF_FORMAT_NO_OUTPUT)) {
    struct line_log_data *range = lookup_line_range(rev, commit);
    dump_diff_hacky(rev, range);
  }
  return 1;
}

static int bloom_filter_check(struct rev_info *rev,
            struct commit *commit,
            struct line_log_data *range)
{
  struct bloom_filter *filter;
  struct bloom_key key;
  int result = 0;

  if (!commit->parents)
    return 1;

  if (!rev->bloom_filter_settings ||
      !(filter = get_bloom_filter(rev->repo, commit)))
    return 1;

  if (!range)
    return 0;

  while (!result && range) {
    fill_bloom_key(range->path, strlen(range->path), &key, rev->bloom_filter_settings);

    if (bloom_filter_contains(filter, &key, rev->bloom_filter_settings))
      result = 1;

    clear_bloom_key(&key);
    range = range->next;
  }

  return result;
}

static int process_ranges_ordinary_commit(struct rev_info *rev, struct commit *commit,
            struct line_log_data *range)
{
  struct commit *parent = NULL;
  struct diff_queue_struct queue;
  struct line_log_data *parent_range;
  int changed;

  if (commit->parents)
    parent = commit->parents->item;

  queue_diffs(range, &rev->diffopt, &queue, commit, parent);
  changed = process_all_files(&parent_range, rev, &queue, range);

  if (parent)
    add_line_range(rev, parent, parent_range);
  free_line_log_data(parent_range);
  diff_free_queue(&queue);
  return changed;
}

static int process_ranges_merge_commit(struct rev_info *rev, struct commit *commit,
               struct line_log_data *range)
{
  struct diff_queue_struct *diffqueues;
  struct line_log_data **cand;
  struct commit **parents;
  struct commit_list *p;
  int i;
  int nparents = commit_list_count(commit->parents);

  if (nparents > 1 && rev->first_parent_only)
    nparents = 1;

  ALLOC_ARRAY(diffqueues, nparents);
  ALLOC_ARRAY(cand, nparents);
  ALLOC_ARRAY(parents, nparents);

  p = commit->parents;
  for (i = 0; i < nparents; i++) {
    parents[i] = p->item;
    p = p->next;
    queue_diffs(range, &rev->diffopt, &diffqueues[i], commit, parents[i]);
  }

  for (i = 0; i < nparents; i++) {
    int changed;
    cand[i] = NULL;
    changed = process_all_files(&cand[i], rev, &diffqueues[i], range);
    if (!changed) {
      /*
       * This parent can take all the blame, so we
       * don't follow any other path in history
       */
      add_line_range(rev, parents[i], cand[i]);
      clear_commit_line_range(rev, commit);
      commit_list_append(parents[i], &commit->parents);
      free(parents);
      free(cand);
      free_diffqueues(nparents, diffqueues);
      /* NEEDSWORK leaking like a sieve */
      return 0;
    }
  }

  /*
   * No single parent took the blame.  We add the candidates
   * from the above loop to the parents.
   */
  for (i = 0; i < nparents; i++) {
    add_line_range(rev, parents[i], cand[i]);
  }

  clear_commit_line_range(rev, commit);
  free(parents);
  free(cand);
  free_diffqueues(nparents, diffqueues);
  return 1;

  /* NEEDSWORK evil merge detection stuff */
  /* NEEDSWORK leaking like a sieve */
}

int line_log_process_ranges_arbitrary_commit(struct rev_info *rev, struct commit *commit)
{
  struct line_log_data *range = lookup_line_range(rev, commit);
  int changed = 0;

  if (range) {
    if (commit->parents && !bloom_filter_check(rev, commit, range)) {
      struct line_log_data *prange = line_log_data_copy(range);
      add_line_range(rev, commit->parents->item, prange);
      clear_commit_line_range(rev, commit);
    } else if (!commit->parents || !commit->parents->next)
      changed = process_ranges_ordinary_commit(rev, commit, range);
    else
      changed = process_ranges_merge_commit(rev, commit, range);
  }

  if (!changed)
    commit->object.flags |= TREESAME;

  return changed;
}

static enum rewrite_result line_log_rewrite_one(struct rev_info *rev UNUSED,
            struct commit **pp)
{
  for (;;) {
    struct commit *p = *pp;
    if (p->parents && p->parents->next)
      return rewrite_one_ok;
    if (p->object.flags & UNINTERESTING)
      return rewrite_one_ok;
    if (!(p->object.flags & TREESAME))
      return rewrite_one_ok;
    if (!p->parents)
      return rewrite_one_noparents;
    *pp = p->parents->item;
  }
}

int line_log_filter(struct rev_info *rev)
{
  struct commit *commit;
  struct commit_list *list = rev->commits;
  struct commit_list *out = NULL, **pp = &out;

  while (list) {
    struct commit_list *to_free = NULL;
    commit = list->item;
    if (line_log_process_ranges_arbitrary_commit(rev, commit)) {
      *pp = list;
      pp = &list->next;
    } else
      to_free = list;
    list = list->next;
    free(to_free);
  }
  *pp = NULL;

  for (list = out; list; list = list->next)
    rewrite_parents(rev, list->item, line_log_rewrite_one);

  rev->commits = out;

  return 0;
}

static void free_void_line_log_data(void *data)
{
  free_line_log_data(data);
}

void line_log_free(struct rev_info *rev)
{
  clear_decoration(&rev->line_log_data, free_void_line_log_data);
}

Coverage Report

Created: 2024-09-08 06:23