git-commit-vandalism/t/helper/test-parse-options.c
Jeff King 517fe807d6 assert NOARG/NONEG behavior of parse-options callbacks
When we define a parse-options callback, the flags we put in the option
struct must match what the callback expects. For example, a callback
which does not handle the "unset" parameter should only be used with
PARSE_OPT_NONEG. But since the callback and the option struct are not
defined next to each other, it's easy to get this wrong (as earlier
patches in this series show).

Fortunately, the compiler can help us here: compiling with
-Wunused-parameters can show us which callbacks ignore their "unset"
parameters (and likewise, ones that ignore "arg" expect to be triggered
with PARSE_OPT_NOARG).

But after we've inspected a callback and determined that all of its
callers use the right flags, what do we do next? We'd like to silence
the compiler warning, but do so in a way that will catch any wrong calls
in the future.

We can do that by actually checking those variables and asserting that
they match our expectations. Because this is such a common pattern,
we'll introduce some helper macros. The resulting messages aren't
as descriptive as we could make them, but the file/line information from
BUG() is enough to identify the problem (and anyway, the point is that
these should never be seen).

Each of the annotated callbacks in this patch triggers
-Wunused-parameters, and was manually inspected to make sure all callers
use the correct options (so none of these BUGs should be triggerable).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-06 12:56:29 +09:00

183 lines
5.5 KiB
C

#include "test-tool.h"
#include "cache.h"
#include "parse-options.h"
#include "string-list.h"
static int boolean = 0;
static int integer = 0;
static unsigned long magnitude = 0;
static timestamp_t timestamp;
static int abbrev = 7;
static int verbose = -1; /* unspecified */
static int dry_run = 0, quiet = 0;
static char *string = NULL;
static char *file = NULL;
static int ambiguous;
static struct string_list list = STRING_LIST_INIT_NODUP;
static struct {
int called;
const char *arg;
int unset;
} length_cb;
static int length_callback(const struct option *opt, const char *arg, int unset)
{
length_cb.called = 1;
length_cb.arg = arg;
length_cb.unset = unset;
if (unset)
return 1; /* do not support unset */
*(int *)opt->value = strlen(arg);
return 0;
}
static int number_callback(const struct option *opt, const char *arg, int unset)
{
BUG_ON_OPT_NEG(unset);
*(int *)opt->value = strtol(arg, NULL, 10);
return 0;
}
static int collect_expect(const struct option *opt, const char *arg, int unset)
{
struct string_list *expect;
struct string_list_item *item;
struct strbuf label = STRBUF_INIT;
const char *colon;
if (!arg || unset)
die("malformed --expect option");
expect = (struct string_list *)opt->value;
colon = strchr(arg, ':');
if (!colon)
die("malformed --expect option, lacking a colon");
strbuf_add(&label, arg, colon - arg);
item = string_list_insert(expect, strbuf_detach(&label, NULL));
if (item->util)
die("malformed --expect option, duplicate %s", label.buf);
item->util = (void *)arg;
return 0;
}
__attribute__((format (printf,3,4)))
static void show(struct string_list *expect, int *status, const char *fmt, ...)
{
struct string_list_item *item;
struct strbuf buf = STRBUF_INIT;
va_list args;
va_start(args, fmt);
strbuf_vaddf(&buf, fmt, args);
va_end(args);
if (!expect->nr)
printf("%s\n", buf.buf);
else {
char *colon = strchr(buf.buf, ':');
if (!colon)
die("malformed output format, output lacking colon: %s", fmt);
*colon = '\0';
item = string_list_lookup(expect, buf.buf);
*colon = ':';
if (!item)
; /* not among entries being checked */
else {
if (strcmp((const char *)item->util, buf.buf)) {
printf("-%s\n", (char *)item->util);
printf("+%s\n", buf.buf);
*status = 1;
}
}
}
strbuf_release(&buf);
}
int cmd__parse_options(int argc, const char **argv)
{
const char *prefix = "prefix/";
const char *usage[] = {
"test-tool parse-options <options>",
"",
"A helper function for the parse-options API.",
NULL
};
struct string_list expect = STRING_LIST_INIT_NODUP;
struct option options[] = {
OPT_BOOL(0, "yes", &boolean, "get a boolean"),
OPT_BOOL('D', "no-doubt", &boolean, "begins with 'no-'"),
{ OPTION_SET_INT, 'B', "no-fear", &boolean, NULL,
"be brave", PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 1 },
OPT_COUNTUP('b', "boolean", &boolean, "increment by one"),
OPT_BIT('4', "or4", &boolean,
"bitwise-or boolean with ...0100", 4),
OPT_NEGBIT(0, "neg-or4", &boolean, "same as --no-or4", 4),
OPT_GROUP(""),
OPT_INTEGER('i', "integer", &integer, "get a integer"),
OPT_INTEGER('j', NULL, &integer, "get a integer, too"),
OPT_MAGNITUDE('m', "magnitude", &magnitude, "get a magnitude"),
OPT_SET_INT(0, "set23", &integer, "set integer to 23", 23),
OPT_CALLBACK('L', "length", &integer, "str",
"get length of <str>", length_callback),
OPT_FILENAME('F', "file", &file, "set file to <file>"),
OPT_GROUP("String options"),
OPT_STRING('s', "string", &string, "string", "get a string"),
OPT_STRING(0, "string2", &string, "str", "get another string"),
OPT_STRING(0, "st", &string, "st", "get another string (pervert ordering)"),
OPT_STRING('o', NULL, &string, "str", "get another string"),
OPT_NOOP_NOARG(0, "obsolete"),
OPT_STRING_LIST(0, "list", &list, "str", "add str to list"),
OPT_GROUP("Magic arguments"),
OPT_ARGUMENT("quux", "means --quux"),
OPT_NUMBER_CALLBACK(&integer, "set integer to NUM",
number_callback),
{ OPTION_COUNTUP, '+', NULL, &boolean, NULL, "same as -b",
PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH },
{ OPTION_COUNTUP, 0, "ambiguous", &ambiguous, NULL,
"positive ambiguity", PARSE_OPT_NOARG | PARSE_OPT_NONEG },
{ OPTION_COUNTUP, 0, "no-ambiguous", &ambiguous, NULL,
"negative ambiguity", PARSE_OPT_NOARG | PARSE_OPT_NONEG },
OPT_GROUP("Standard options"),
OPT__ABBREV(&abbrev),
OPT__VERBOSE(&verbose, "be verbose"),
OPT__DRY_RUN(&dry_run, "dry run"),
OPT__QUIET(&quiet, "be quiet"),
OPT_CALLBACK(0, "expect", &expect, "string",
"expected output in the variable dump",
collect_expect),
OPT_END(),
};
int i;
int ret = 0;
argc = parse_options(argc, (const char **)argv, prefix, options, usage, 0);
if (length_cb.called) {
const char *arg = length_cb.arg;
int unset = length_cb.unset;
show(&expect, &ret, "Callback: \"%s\", %d",
(arg ? arg : "not set"), unset);
}
show(&expect, &ret, "boolean: %d", boolean);
show(&expect, &ret, "integer: %d", integer);
show(&expect, &ret, "magnitude: %lu", magnitude);
show(&expect, &ret, "timestamp: %"PRItime, timestamp);
show(&expect, &ret, "string: %s", string ? string : "(not set)");
show(&expect, &ret, "abbrev: %d", abbrev);
show(&expect, &ret, "verbose: %d", verbose);
show(&expect, &ret, "quiet: %d", quiet);
show(&expect, &ret, "dry run: %s", dry_run ? "yes" : "no");
show(&expect, &ret, "file: %s", file ? file : "(not set)");
for (i = 0; i < list.nr; i++)
show(&expect, &ret, "list: %s", list.items[i].string);
for (i = 0; i < argc; i++)
show(&expect, &ret, "arg %02d: %s", i, argv[i]);
return ret;
}