git/t/helper/test-trace2.c
Ævar Arnfjörð Bjarmason 368b584315 common-main.c: call exit(), don't return
Change the main() function to call "exit()" instead of ending with a
"return" statement. The "exit()" function is our own wrapper that
calls trace2_cmd_exit_fl() for us, from git-compat-util.h:

	#define exit(code) exit(trace2_cmd_exit_fl(__FILE__, __LINE__, (code)))

That "exit()" wrapper has been in use ever since ee4512ed48 (trace2:
create new combined trace facility, 2019-02-22).

This changes nothing about how we "exit()", as we'd invoke
"trace2_cmd_exit_fl()" in both cases due to the wrapper, this change
makes it easier to reason about this code, as we're now always
obviously relying on our "exit()" wrapper.

There is already code immediately downstream of our "main()" which has
a hard reliance on that, e.g. the various "exit()" calls downstream of
"cmd_main()" in "git.c".

We even had a comment in "t/helper/test-trace2.c" that seemed to be
confused about how the "exit()" wrapper interacted with uses of
"return", even though it was introduced in the same trace2 series in
a15860dca3 (trace2: t/helper/test-trace2, t0210.sh, t0211.sh,
t0212.sh, 2019-02-22), after the aforementioned ee4512ed48. Perhaps
it pre-dated the "exit()" wrapper?

This change makes the "trace2_cmd_exit()" macro orphaned, we now
always use "trace2_cmd_exit_fl()" directly, but let's keep that
simpler example in place. Even if we're unlikely to get another
"main()" other than the one in our "common-main.c", there's some value
in having the API documentation and example discuss a simpler version
that doesn't require an "exit()" wrapper macro.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 12:29:57 -08:00

284 lines
7.7 KiB
C

#include "test-tool.h"
#include "cache.h"
#include "strvec.h"
#include "run-command.h"
#include "exec-cmd.h"
#include "config.h"
typedef int(fn_unit_test)(int argc, const char **argv);
struct unit_test {
fn_unit_test *ut_fn;
const char *ut_name;
const char *ut_usage;
};
#define MyOk 0
#define MyError 1
static int get_i(int *p_value, const char *data)
{
char *endptr;
if (!data || !*data)
return MyError;
*p_value = strtol(data, &endptr, 10);
if (*endptr || errno == ERANGE)
return MyError;
return MyOk;
}
/*
* Cause process to exit with the requested value via "return".
*
* Rely on test-tool.c:cmd_main() to call trace2_cmd_exit()
* with our result.
*
* Test harness can confirm:
* [] the process-exit value.
* [] the "code" field in the "exit" trace2 event.
* [] the "code" field in the "atexit" trace2 event.
* [] the "name" field in the "cmd_name" trace2 event.
* [] "def_param" events for all of the "interesting" pre-defined
* config settings.
*/
static int ut_001return(int argc, const char **argv)
{
int rc;
if (get_i(&rc, argv[0]))
die("expect <exit_code>");
return rc;
}
/*
* Cause the process to exit with the requested value via "exit()".
*
* Test harness can confirm:
* [] the "code" field in the "exit" trace2 event.
* [] the "code" field in the "atexit" trace2 event.
* [] the "name" field in the "cmd_name" trace2 event.
* [] "def_param" events for all of the "interesting" pre-defined
* config settings.
*/
static int ut_002exit(int argc, const char **argv)
{
int rc;
if (get_i(&rc, argv[0]))
die("expect <exit_code>");
exit(rc);
}
/*
* Send an "error" event with each value in argv. Normally, git only issues
* a single "error" event immediately before issuing an "exit" event (such
* as in die() or BUG()), but multiple "error" events are allowed.
*
* Test harness can confirm:
* [] a trace2 "error" event for each value in argv.
* [] the "name" field in the "cmd_name" trace2 event.
* [] (optional) the file:line in the "exit" event refers to this function.
*/
static int ut_003error(int argc, const char **argv)
{
int k;
if (!argv[0] || !*argv[0])
die("expect <error_message>");
for (k = 0; k < argc; k++)
error("%s", argv[k]);
return 0;
}
/*
* Run a child process and wait for it to finish and exit with its return code.
* test-tool trace2 004child [<child-command-line>]
*
* For example:
* test-tool trace2 004child git version
* test-tool trace2 004child test-tool trace2 001return 0
* test-tool trace2 004child test-tool trace2 004child test-tool trace2 004child
* test-tool trace2 004child git -c alias.xyz=version xyz
*
* Test harness can confirm:
* [] the "name" field in the "cmd_name" trace2 event.
* [] that the outer process has a single component SID (or depth "d0" in
* the PERF stream).
* [] that "child_start" and "child_exit" events are generated for the child.
* [] if the child process is an instrumented executable:
* [] that "version", "start", ..., "exit", and "atexit" events are
* generated by the child process.
* [] that the child process events have a multiple component SID (or
* depth "dN+1" in the PERF stream).
* [] that the child exit code is propagated to the parent process "exit"
* and "atexit" events..
* [] (optional) that the "t_abs" field in the child process "atexit" event
* is less than the "t_rel" field in the "child_exit" event of the parent
* process.
* [] if the child process is like the alias example above,
* [] (optional) the child process attempts to run "git-xyx" as a dashed
* command.
* [] the child process emits an "alias" event with "xyz" => "version"
* [] the child process runs "git version" as a child process.
* [] the child process has a 3 component SID (or depth "d2" in the PERF
* stream).
*/
static int ut_004child(int argc, const char **argv)
{
int result;
/*
* Allow empty <child_command_line> so we can do arbitrarily deep
* command nesting and let the last one be null.
*/
if (!argc)
return 0;
result = run_command_v_opt(argv, 0);
exit(result);
}
/*
* Exec a git command. This may either create a child process (Windows)
* or replace the existing process.
* test-tool trace2 005exec <git_command_args>
*
* For example:
* test-tool trace2 005exec version
*
* Test harness can confirm (on Windows):
* [] the "name" field in the "cmd_name" trace2 event.
* [] that the outer process has a single component SID (or depth "d0" in
* the PERF stream).
* [] that "exec" and "exec_result" events are generated for the child
* process (since the Windows compatibility layer fakes an exec() with
* a CreateProcess(), WaitForSingleObject(), and exit()).
* [] that the child process has multiple component SID (or depth "dN+1"
* in the PERF stream).
*
* Test harness can confirm (on platforms with a real exec() function):
* [] TODO talk about process replacement and how it affects SID.
*/
static int ut_005exec(int argc, const char **argv)
{
int result;
if (!argc)
return 0;
result = execv_git_cmd(argv);
return result;
}
static int ut_006data(int argc, const char **argv)
{
const char *usage_error =
"expect <cat0> <k0> <v0> [<cat1> <k1> <v1> [...]]";
if (argc % 3 != 0)
die("%s", usage_error);
while (argc) {
if (!argv[0] || !*argv[0] || !argv[1] || !*argv[1] ||
!argv[2] || !*argv[2])
die("%s", usage_error);
trace2_data_string(argv[0], the_repository, argv[1], argv[2]);
argv += 3;
argc -= 3;
}
return 0;
}
static int ut_007bug(int argc, const char **argv)
{
/*
* Exercise BUG() to ensure that the message is printed to trace2.
*/
BUG("the bug message");
}
/*
* Usage:
* test-tool trace2 <ut_name_1> <ut_usage_1>
* test-tool trace2 <ut_name_2> <ut_usage_2>
* ...
*/
#define USAGE_PREFIX "test-tool trace2"
/* clang-format off */
static struct unit_test ut_table[] = {
{ ut_001return, "001return", "<exit_code>" },
{ ut_002exit, "002exit", "<exit_code>" },
{ ut_003error, "003error", "<error_message>+" },
{ ut_004child, "004child", "[<child_command_line>]" },
{ ut_005exec, "005exec", "<git_command_args>" },
{ ut_006data, "006data", "[<category> <key> <value>]+" },
{ ut_007bug, "007bug", "" },
};
/* clang-format on */
/* clang-format off */
#define for_each_ut(k, ut_k) \
for (k = 0, ut_k = &ut_table[k]; \
k < ARRAY_SIZE(ut_table); \
k++, ut_k = &ut_table[k])
/* clang-format on */
static int print_usage(void)
{
int k;
struct unit_test *ut_k;
fprintf(stderr, "usage:\n");
for_each_ut (k, ut_k)
fprintf(stderr, "\t%s %s %s\n", USAGE_PREFIX, ut_k->ut_name,
ut_k->ut_usage);
return 129;
}
/*
* Issue various trace2 events for testing.
*
* We assume that these trace2 routines has already been called:
* [] trace2_initialize() [common-main.c:main()]
* [] trace2_cmd_start() [common-main.c:main()]
* [] trace2_cmd_name() [test-tool.c:cmd_main()]
* [] tracd2_cmd_list_config() [test-tool.c:cmd_main()]
* So that:
* [] the various trace2 streams are open.
* [] the process SID has been created.
* [] the "version" event has been generated.
* [] the "start" event has been generated.
* [] the "cmd_name" event has been generated.
* [] this writes various "def_param" events for interesting config values.
*
* We return from here and let test-tool.c::cmd_main() pass the exit
* code to common-main.c::main(), which will use it to call
* trace2_cmd_exit().
*/
int cmd__trace2(int argc, const char **argv)
{
int k;
struct unit_test *ut_k;
argc--; /* skip over "trace2" arg */
argv++;
if (argc)
for_each_ut (k, ut_k)
if (!strcmp(argv[0], ut_k->ut_name))
return ut_k->ut_fn(argc - 1, argv + 1);
return print_usage();
}