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git/range-diff.c
Jeff King beaa1d952b hashmap: use expected signatures for comparison functions 
We prefer for callback functions to match the signature with which
they'll be called, rather than casting them to the correct type when
assigning function pointers. Even though casting often works in the real
world, it is a violation of the standard.

We did a mass conversion in 939af16eac (hashmap_cmp_fn takes
hashmap_entry params, 2019-10-06), but have grown a few new cases since
then. Because of the cast, the compiler does not complain. However, as
of clang-18, UBSan will catch these at run-time, and the case in
range-diff.c triggers when running t3206.

After seeing that one, I scanned the results of:

  git grep '_fn)[^(]' '*.c' | grep -v typedef

and found a similar case in compat/terminal.c (which presumably isn't
called in the test suite, since it doesn't trigger UBSan). There might
be other cases lurking if the cast is done using a typedef that doesn't
end in "_fn", but loosening it finds too many false positives. I also
looked for:

  git grep ' = ([a-z_]*) *[a-z]' '*.c'

to find assignments that cast, but nothing looked like a function.

The resulting code is unfortunately a little longer, but the bonus of
using container_of() is that we are no longer restricted to the
hashmap_entry being at the start of the struct.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-08-19 21:17:53 -07:00

619 lines
16 KiB
C
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#include "git-compat-util.h"
#include "environment.h"
#include "gettext.h"
#include "range-diff.h"
#include "object-name.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 "pager.h"
#include "pretty.h"
#include "repository.h"
#include "userdiff.h"
#include "apply.h"
#include "revision.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;
};
/*
* 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;
ssize_t len;
size_t size;
int ret = -1;
strvec_pushl(&cp.args, "log", "--no-color", "-p", "--no-merges",
"--reverse", "--date-order", "--decorate=no",
"--no-prefix", "--submodule=short",
/*
* 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);
strvec_push(&cp.args, range);
if (other_arg)
strvec_pushv(&cp.args, other_arg->v);
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);
goto cleanup;
}
if (finish_command(&cp))
goto cleanup;
line = contents.buf;
size = contents.len;
for (; size > 0; size -= len, line += len) {
const char *p;
char *eol;
eol = memchr(line, '\n', size);
if (eol) {
*eol = '\0';
len = eol + 1 - line;
} else {
len = size;
}
if (skip_prefix(line, "commit ", &p)) {
if (util) {
string_list_append(list, buf.buf)->util = util;
strbuf_reset(&buf);
}
CALLOC_ARRAY(util, 1);
if (repo_get_oid(the_repository, p, &util->oid)) {
error(_("could not parse commit '%s'"), p);
FREE_AND_NULL(util);
string_list_clear(list, 1);
goto cleanup;
}
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);
goto cleanup;
}
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;
if (eol)
*eol = '\n';
orig_len = len;
len = parse_git_diff_header(&root, &linenr, 0, line,
len, size, &patch);
if (len < 0) {
error(_("could not parse git header '%.*s'"),
orig_len, line);
FREE_AND_NULL(util);
string_list_clear(list, 1);
goto cleanup;
}
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, " ##");
release_patch(&patch);
} 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++;
}
ret = 0;
cleanup:
strbuf_release(&contents);
if (util)
string_list_append(list, buf.buf)->util = util;
strbuf_release(&buf);
free(current_filename);
return ret;
}
static int patch_util_cmp(const void *cmp_data UNUSED,
const struct hashmap_entry *ha,
const struct hashmap_entry *hb,
const void *keydata)
{
const struct patch_util
*a = container_of(ha, const struct patch_util, e),
*b = container_of(hb, const struct patch_util, e);
return strcmp(a->diff, keydata ? keydata : b->diff);
}
static void find_exact_matches(struct string_list *a, struct string_list *b)
{
struct hashmap map = HASHMAP_INIT(patch_util_cmp, NULL);
int i;
/* 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_clear(&map);
}
static int diffsize_consume(void *data,
char *line UNUSED,
unsigned long len UNUSED)
{
(*(int *)data)++;
return 0;
}
static void diffsize_hunk(void *data,
long ob UNUSED, long on UNUSED,
long nb UNUSED, long nn UNUSED,
const char *func UNUSED, long funclen UNUSED)
{
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;
int abbrev = diffopt->abbrev;
if (abbrev < 0)
abbrev = DEFAULT_ABBREV;
if (!dashes->len)
strbuf_addchars(dashes, '-',
strlen(repo_find_unique_abbrev(the_repository, oid, 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,
repo_find_unique_abbrev(the_repository, &a_util->oid, 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,
repo_find_unique_abbrev(the_repository, &b_util->oid, 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 struct strbuf *output_prefix_cb(struct diff_options *opt UNUSED, void *data)
{
return data;
}
static void output(struct string_list *a, struct string_list *b,
struct range_diff_options *range_diff_opts)
{
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;
struct diff_options opts;
struct strbuf indent = STRBUF_INIT;
if (range_diff_opts->diffopt)
memcpy(&opts, range_diff_opts->diffopt, sizeof(opts));
else
repo_diff_setup(the_repository, &opts);
opts.no_free = 1;
if (!opts.output_format)
opts.output_format = DIFF_FORMAT_PATCH;
opts.flags.suppress_diff_headers = 1;
opts.flags.dual_color_diffed_diffs =
range_diff_opts->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);
/*
* 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) {
if (!range_diff_opts->right_only)
output_pair_header(&opts, patch_no_width,
&buf, &dashes, a_util, NULL);
i++;
continue;
}
/* Show unmatched RHS commits. */
while (j < b->nr && b_util->matching < 0) {
if (!range_diff_opts->left_only)
output_pair_header(&opts, 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(&opts, patch_no_width,
&buf, &dashes, a_util, b_util);
if (!(opts.output_format & DIFF_FORMAT_NO_OUTPUT))
patch_diff(a->items[b_util->matching].string,
b->items[j].string, &opts);
a_util->shown = 1;
j++;
}
}
strbuf_release(&buf);
strbuf_release(&dashes);
strbuf_release(&indent);
opts.no_free = 0;
diff_free(&opts);
}
int show_range_diff(const char *range1, const char *range2,
struct range_diff_options *range_diff_opts)
{
int res = 0;
struct string_list branch1 = STRING_LIST_INIT_DUP;
struct string_list branch2 = STRING_LIST_INIT_DUP;
if (range_diff_opts->left_only && range_diff_opts->right_only)
res = error(_("options '%s' and '%s' cannot be used together"), "--left-only", "--right-only");
if (!res && read_patches(range1, &branch1, range_diff_opts->other_arg))
res = error(_("could not parse log for '%s'"), range1);
if (!res && read_patches(range2, &branch2, range_diff_opts->other_arg))
res = error(_("could not parse log for '%s'"), range2);
if (!res) {
find_exact_matches(&branch1, &branch2);
get_correspondences(&branch1, &branch2,
range_diff_opts->creation_factor);
output(&branch1, &branch2, range_diff_opts);
}
string_list_clear(&branch1, 1);
string_list_clear(&branch2, 1);
return res;
}
int is_range_diff_range(const char *arg)
{
char *copy = xstrdup(arg); /* setup_revisions() modifies it */
const char *argv[] = { "", copy, "--", NULL };
int i, positive = 0, negative = 0;
struct rev_info revs;
repo_init_revisions(the_repository, &revs, NULL);
if (setup_revisions(3, argv, &revs, NULL) == 1) {
for (i = 0; i < revs.pending.nr; i++)
if (revs.pending.objects[i].item->flags & UNINTERESTING)
negative++;
else
positive++;
for (i = 0; i < revs.pending.nr; i++) {
struct object *obj = revs.pending.objects[i].item;
if (obj->type == OBJ_COMMIT)
clear_commit_marks((struct commit *)obj,
ALL_REV_FLAGS);
}
}
free(copy);
release_revisions(&revs);
return negative > 0 && positive > 0;
}
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