tvl-depot/third_party/git/range-diff.c
Vincent Ambo f4609b896f merge(3p/git): Merge git subtree at v2.29.2
This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb
2020-11-21 19:45:56 +01:00

568 lines
15 KiB
C

#include "cache.h"
#include "range-diff.h"
#include "string-list.h"
#include "run-command.h"
#include "strvec.h"
#include "hashmap.h"
#include "xdiff-interface.h"
#include "linear-assignment.h"
#include "diffcore.h"
#include "commit.h"
#include "pretty.h"
#include "userdiff.h"
#include "apply.h"
struct patch_util {
/* For the search for an exact match */
struct hashmap_entry e;
const char *diff, *patch;
int i, shown;
int diffsize;
size_t diff_offset;
/* the index of the matching item in the other branch, or -1 */
int matching;
struct object_id oid;
};
static size_t find_end_of_line(char *buffer, unsigned long size)
{
char *eol = memchr(buffer, '\n', size);
if (!eol)
return size;
*eol = '\0';
return eol + 1 - buffer;
}
/*
* Reads the patches into a string list, with the `util` field being populated
* as struct object_id (will need to be free()d).
*/
static int read_patches(const char *range, struct string_list *list,
const struct strvec *other_arg)
{
struct child_process cp = CHILD_PROCESS_INIT;
struct strbuf buf = STRBUF_INIT, contents = STRBUF_INIT;
struct patch_util *util = NULL;
int in_header = 1;
char *line, *current_filename = NULL;
int offset, len;
size_t size;
strvec_pushl(&cp.args, "log", "--no-color", "-p", "--no-merges",
"--reverse", "--date-order", "--decorate=no",
"--no-prefix",
/*
* Choose indicators that are not used anywhere
* else in diffs, but still look reasonable
* (e.g. will not be confusing when debugging)
*/
"--output-indicator-new=>",
"--output-indicator-old=<",
"--output-indicator-context=#",
"--no-abbrev-commit",
"--pretty=medium",
"--notes",
NULL);
if (other_arg)
strvec_pushv(&cp.args, other_arg->v);
strvec_push(&cp.args, range);
cp.out = -1;
cp.no_stdin = 1;
cp.git_cmd = 1;
if (start_command(&cp))
return error_errno(_("could not start `log`"));
if (strbuf_read(&contents, cp.out, 0) < 0) {
error_errno(_("could not read `log` output"));
finish_command(&cp);
return -1;
}
line = contents.buf;
size = contents.len;
for (offset = 0; size > 0; offset += len, size -= len, line += len) {
const char *p;
len = find_end_of_line(line, size);
line[len - 1] = '\0';
if (skip_prefix(line, "commit ", &p)) {
if (util) {
string_list_append(list, buf.buf)->util = util;
strbuf_reset(&buf);
}
util = xcalloc(sizeof(*util), 1);
if (get_oid(p, &util->oid)) {
error(_("could not parse commit '%s'"), p);
free(util);
string_list_clear(list, 1);
strbuf_release(&buf);
strbuf_release(&contents);
finish_command(&cp);
return -1;
}
util->matching = -1;
in_header = 1;
continue;
}
if (!util) {
error(_("could not parse first line of `log` output: "
"did not start with 'commit ': '%s'"),
line);
string_list_clear(list, 1);
strbuf_release(&buf);
strbuf_release(&contents);
finish_command(&cp);
return -1;
}
if (starts_with(line, "diff --git")) {
struct patch patch = { 0 };
struct strbuf root = STRBUF_INIT;
int linenr = 0;
int orig_len;
in_header = 0;
strbuf_addch(&buf, '\n');
if (!util->diff_offset)
util->diff_offset = buf.len;
line[len - 1] = '\n';
orig_len = len;
len = parse_git_diff_header(&root, &linenr, 0, line,
len, size, &patch);
if (len < 0)
die(_("could not parse git header '%.*s'"),
orig_len, line);
strbuf_addstr(&buf, " ## ");
if (patch.is_new > 0)
strbuf_addf(&buf, "%s (new)", patch.new_name);
else if (patch.is_delete > 0)
strbuf_addf(&buf, "%s (deleted)", patch.old_name);
else if (patch.is_rename)
strbuf_addf(&buf, "%s => %s", patch.old_name, patch.new_name);
else
strbuf_addstr(&buf, patch.new_name);
free(current_filename);
if (patch.is_delete > 0)
current_filename = xstrdup(patch.old_name);
else
current_filename = xstrdup(patch.new_name);
if (patch.new_mode && patch.old_mode &&
patch.old_mode != patch.new_mode)
strbuf_addf(&buf, " (mode change %06o => %06o)",
patch.old_mode, patch.new_mode);
strbuf_addstr(&buf, " ##");
} else if (in_header) {
if (starts_with(line, "Author: ")) {
strbuf_addstr(&buf, " ## Metadata ##\n");
strbuf_addstr(&buf, line);
strbuf_addstr(&buf, "\n\n");
strbuf_addstr(&buf, " ## Commit message ##\n");
} else if (starts_with(line, "Notes") &&
line[strlen(line) - 1] == ':') {
strbuf_addstr(&buf, "\n\n");
/* strip the trailing colon */
strbuf_addf(&buf, " ## %.*s ##\n",
(int)(strlen(line) - 1), line);
} else if (starts_with(line, " ")) {
p = line + len - 2;
while (isspace(*p) && p >= line)
p--;
strbuf_add(&buf, line, p - line + 1);
strbuf_addch(&buf, '\n');
}
continue;
} else if (skip_prefix(line, "@@ ", &p)) {
p = strstr(p, "@@");
strbuf_addstr(&buf, "@@");
if (current_filename && p[2])
strbuf_addf(&buf, " %s:", current_filename);
if (p)
strbuf_addstr(&buf, p + 2);
} else if (!line[0])
/*
* A completely blank (not ' \n', which is context)
* line is not valid in a diff. We skip it
* silently, because this neatly handles the blank
* separator line between commits in git-log
* output.
*/
continue;
else if (line[0] == '>') {
strbuf_addch(&buf, '+');
strbuf_addstr(&buf, line + 1);
} else if (line[0] == '<') {
strbuf_addch(&buf, '-');
strbuf_addstr(&buf, line + 1);
} else if (line[0] == '#') {
strbuf_addch(&buf, ' ');
strbuf_addstr(&buf, line + 1);
} else {
strbuf_addch(&buf, ' ');
strbuf_addstr(&buf, line);
}
strbuf_addch(&buf, '\n');
util->diffsize++;
}
strbuf_release(&contents);
if (util)
string_list_append(list, buf.buf)->util = util;
strbuf_release(&buf);
free(current_filename);
if (finish_command(&cp))
return -1;
return 0;
}
static int patch_util_cmp(const void *dummy, const struct patch_util *a,
const struct patch_util *b, const char *keydata)
{
return strcmp(a->diff, keydata ? keydata : b->diff);
}
static void find_exact_matches(struct string_list *a, struct string_list *b)
{
struct hashmap map;
int i;
hashmap_init(&map, (hashmap_cmp_fn)patch_util_cmp, NULL, 0);
/* First, add the patches of a to a hash map */
for (i = 0; i < a->nr; i++) {
struct patch_util *util = a->items[i].util;
util->i = i;
util->patch = a->items[i].string;
util->diff = util->patch + util->diff_offset;
hashmap_entry_init(&util->e, strhash(util->diff));
hashmap_add(&map, &util->e);
}
/* Now try to find exact matches in b */
for (i = 0; i < b->nr; i++) {
struct patch_util *util = b->items[i].util, *other;
util->i = i;
util->patch = b->items[i].string;
util->diff = util->patch + util->diff_offset;
hashmap_entry_init(&util->e, strhash(util->diff));
other = hashmap_remove_entry(&map, util, e, NULL);
if (other) {
if (other->matching >= 0)
BUG("already assigned!");
other->matching = i;
util->matching = other->i;
}
}
hashmap_free(&map);
}
static void diffsize_consume(void *data, char *line, unsigned long len)
{
(*(int *)data)++;
}
static void diffsize_hunk(void *data, long ob, long on, long nb, long nn,
const char *funcline, long funclen)
{
diffsize_consume(data, NULL, 0);
}
static int diffsize(const char *a, const char *b)
{
xpparam_t pp = { 0 };
xdemitconf_t cfg = { 0 };
mmfile_t mf1, mf2;
int count = 0;
mf1.ptr = (char *)a;
mf1.size = strlen(a);
mf2.ptr = (char *)b;
mf2.size = strlen(b);
cfg.ctxlen = 3;
if (!xdi_diff_outf(&mf1, &mf2,
diffsize_hunk, diffsize_consume, &count,
&pp, &cfg))
return count;
error(_("failed to generate diff"));
return COST_MAX;
}
static void get_correspondences(struct string_list *a, struct string_list *b,
int creation_factor)
{
int n = a->nr + b->nr;
int *cost, c, *a2b, *b2a;
int i, j;
ALLOC_ARRAY(cost, st_mult(n, n));
ALLOC_ARRAY(a2b, n);
ALLOC_ARRAY(b2a, n);
for (i = 0; i < a->nr; i++) {
struct patch_util *a_util = a->items[i].util;
for (j = 0; j < b->nr; j++) {
struct patch_util *b_util = b->items[j].util;
if (a_util->matching == j)
c = 0;
else if (a_util->matching < 0 && b_util->matching < 0)
c = diffsize(a_util->diff, b_util->diff);
else
c = COST_MAX;
cost[i + n * j] = c;
}
c = a_util->matching < 0 ?
a_util->diffsize * creation_factor / 100 : COST_MAX;
for (j = b->nr; j < n; j++)
cost[i + n * j] = c;
}
for (j = 0; j < b->nr; j++) {
struct patch_util *util = b->items[j].util;
c = util->matching < 0 ?
util->diffsize * creation_factor / 100 : COST_MAX;
for (i = a->nr; i < n; i++)
cost[i + n * j] = c;
}
for (i = a->nr; i < n; i++)
for (j = b->nr; j < n; j++)
cost[i + n * j] = 0;
compute_assignment(n, n, cost, a2b, b2a);
for (i = 0; i < a->nr; i++)
if (a2b[i] >= 0 && a2b[i] < b->nr) {
struct patch_util *a_util = a->items[i].util;
struct patch_util *b_util = b->items[a2b[i]].util;
a_util->matching = a2b[i];
b_util->matching = i;
}
free(cost);
free(a2b);
free(b2a);
}
static void output_pair_header(struct diff_options *diffopt,
int patch_no_width,
struct strbuf *buf,
struct strbuf *dashes,
struct patch_util *a_util,
struct patch_util *b_util)
{
struct object_id *oid = a_util ? &a_util->oid : &b_util->oid;
struct commit *commit;
char status;
const char *color_reset = diff_get_color_opt(diffopt, DIFF_RESET);
const char *color_old = diff_get_color_opt(diffopt, DIFF_FILE_OLD);
const char *color_new = diff_get_color_opt(diffopt, DIFF_FILE_NEW);
const char *color_commit = diff_get_color_opt(diffopt, DIFF_COMMIT);
const char *color;
if (!dashes->len)
strbuf_addchars(dashes, '-',
strlen(find_unique_abbrev(oid,
DEFAULT_ABBREV)));
if (!b_util) {
color = color_old;
status = '<';
} else if (!a_util) {
color = color_new;
status = '>';
} else if (strcmp(a_util->patch, b_util->patch)) {
color = color_commit;
status = '!';
} else {
color = color_commit;
status = '=';
}
strbuf_reset(buf);
strbuf_addstr(buf, status == '!' ? color_old : color);
if (!a_util)
strbuf_addf(buf, "%*s: %s ", patch_no_width, "-", dashes->buf);
else
strbuf_addf(buf, "%*d: %s ", patch_no_width, a_util->i + 1,
find_unique_abbrev(&a_util->oid, DEFAULT_ABBREV));
if (status == '!')
strbuf_addf(buf, "%s%s", color_reset, color);
strbuf_addch(buf, status);
if (status == '!')
strbuf_addf(buf, "%s%s", color_reset, color_new);
if (!b_util)
strbuf_addf(buf, " %*s: %s", patch_no_width, "-", dashes->buf);
else
strbuf_addf(buf, " %*d: %s", patch_no_width, b_util->i + 1,
find_unique_abbrev(&b_util->oid, DEFAULT_ABBREV));
commit = lookup_commit_reference(the_repository, oid);
if (commit) {
if (status == '!')
strbuf_addf(buf, "%s%s", color_reset, color);
strbuf_addch(buf, ' ');
pp_commit_easy(CMIT_FMT_ONELINE, commit, buf);
}
strbuf_addf(buf, "%s\n", color_reset);
fwrite(buf->buf, buf->len, 1, diffopt->file);
}
static struct userdiff_driver section_headers = {
.funcname = { "^ ## (.*) ##$\n"
"^.?@@ (.*)$", REG_EXTENDED }
};
static struct diff_filespec *get_filespec(const char *name, const char *p)
{
struct diff_filespec *spec = alloc_filespec(name);
fill_filespec(spec, &null_oid, 0, 0100644);
spec->data = (char *)p;
spec->size = strlen(p);
spec->should_munmap = 0;
spec->is_stdin = 1;
spec->driver = &section_headers;
return spec;
}
static void patch_diff(const char *a, const char *b,
struct diff_options *diffopt)
{
diff_queue(&diff_queued_diff,
get_filespec("a", a), get_filespec("b", b));
diffcore_std(diffopt);
diff_flush(diffopt);
}
static void output(struct string_list *a, struct string_list *b,
struct diff_options *diffopt)
{
struct strbuf buf = STRBUF_INIT, dashes = STRBUF_INIT;
int patch_no_width = decimal_width(1 + (a->nr > b->nr ? a->nr : b->nr));
int i = 0, j = 0;
/*
* We assume the user is really more interested in the second argument
* ("newer" version). To that end, we print the output in the order of
* the RHS (the `b` parameter). To put the LHS (the `a` parameter)
* commits that are no longer in the RHS into a good place, we place
* them once we have shown all of their predecessors in the LHS.
*/
while (i < a->nr || j < b->nr) {
struct patch_util *a_util, *b_util;
a_util = i < a->nr ? a->items[i].util : NULL;
b_util = j < b->nr ? b->items[j].util : NULL;
/* Skip all the already-shown commits from the LHS. */
while (i < a->nr && a_util->shown)
a_util = ++i < a->nr ? a->items[i].util : NULL;
/* Show unmatched LHS commit whose predecessors were shown. */
if (i < a->nr && a_util->matching < 0) {
output_pair_header(diffopt, patch_no_width,
&buf, &dashes, a_util, NULL);
i++;
continue;
}
/* Show unmatched RHS commits. */
while (j < b->nr && b_util->matching < 0) {
output_pair_header(diffopt, patch_no_width,
&buf, &dashes, NULL, b_util);
b_util = ++j < b->nr ? b->items[j].util : NULL;
}
/* Show matching LHS/RHS pair. */
if (j < b->nr) {
a_util = a->items[b_util->matching].util;
output_pair_header(diffopt, patch_no_width,
&buf, &dashes, a_util, b_util);
if (!(diffopt->output_format & DIFF_FORMAT_NO_OUTPUT))
patch_diff(a->items[b_util->matching].string,
b->items[j].string, diffopt);
a_util->shown = 1;
j++;
}
}
strbuf_release(&buf);
strbuf_release(&dashes);
}
static struct strbuf *output_prefix_cb(struct diff_options *opt, void *data)
{
return data;
}
int show_range_diff(const char *range1, const char *range2,
int creation_factor, int dual_color,
const struct diff_options *diffopt,
const struct strvec *other_arg)
{
int res = 0;
struct string_list branch1 = STRING_LIST_INIT_DUP;
struct string_list branch2 = STRING_LIST_INIT_DUP;
if (read_patches(range1, &branch1, other_arg))
res = error(_("could not parse log for '%s'"), range1);
if (!res && read_patches(range2, &branch2, other_arg))
res = error(_("could not parse log for '%s'"), range2);
if (!res) {
struct diff_options opts;
struct strbuf indent = STRBUF_INIT;
if (diffopt)
memcpy(&opts, diffopt, sizeof(opts));
else
diff_setup(&opts);
if (!opts.output_format)
opts.output_format = DIFF_FORMAT_PATCH;
opts.flags.suppress_diff_headers = 1;
opts.flags.dual_color_diffed_diffs = dual_color;
opts.flags.suppress_hunk_header_line_count = 1;
opts.output_prefix = output_prefix_cb;
strbuf_addstr(&indent, " ");
opts.output_prefix_data = &indent;
diff_setup_done(&opts);
find_exact_matches(&branch1, &branch2);
get_correspondences(&branch1, &branch2, creation_factor);
output(&branch1, &branch2, &opts);
strbuf_release(&indent);
}
string_list_clear(&branch1, 1);
string_list_clear(&branch2, 1);
return res;
}