Hi, Sergey,

thanks for review!

Hi, Sergey!
Thanks for the patch!
LGTM, after fixing minor nits below.

On 13.02.25, Sergey Bronnikov wrote:

sysprof and memprof Lua API functions returns an error message

Typo: s/returns/return/

"profiler misuse", when appropriate profiler is disabled in build.

Typo: s/appropriate/the corresponding/
Typo: s/build/the build/

It is not possible to easily distinquish whether it is really

Typo: s/distinquish/distinguish/

misuse or profiler was not enabled in build. The patch changes

Typo: s/profiler/or if the profiler/
Typo: s/build/the build/

errors messages, so when profiler was not enabled in build message

Typo: s/errors/error/
Typo: s/profiler/a profiler/
Typo: s/was/is/
Typo: s/in build message/in the build, the message/

is the following: "profiler misuse: profiler is disabled".
---
 src/lib_misc.c                                | 27 ++++++++++++++++-
 src/lj_errmsg.h                               |  1 +
 .../misclib-memprof-lapi-disabled.test.lua    | 22 ++++++++++++++
 .../misclib-sysprof-lapi-disabled.test.lua    | 29 +++++++++++++++++++
 4 files changed, 78 insertions(+), 1 deletion(-)
 create mode 100644 test/tarantool-tests/profilers/misclib-memprof-lapi-disabled.test.lua
 create mode 100644 test/tarantool-tests/profilers/misclib-sysprof-lapi-disabled.test.lua

diff --git a/src/lib_misc.c b/src/lib_misc.c
index d71904e4..7666d85f 100644
--- a/src/lib_misc.c
+++ b/src/lib_misc.c
@@ -315,10 +315,15 @@ static int sysprof_error(lua_State *L, int status, const char *err_details)
 /* local res, err, errno = sysprof.start(options) */
 LJLIB_CF(misc_sysprof_start)
 {
+  const char *err_details = NULL;
+#if !LJ_HASSYSPROF

It's more LuaJIT-way to use something like the following:
| if (!LJ_HASSYSPROF) {
|   /* ... */
| }

This helps to avoid strange early return.

Also, please be avaired to declare all variables (stataus, opt,
err_details) in the beginning of the block.

 It is a requirement for the code that strictly follows c89, when you must declare all of your variables at the beginning of a scope block.

AFAIK, we have no such requirement, and also there is no option "-std=c89" in CI and no any mentions in the contribution guide.

Here and below.

+  err_details = err2msg(LJ_ERR_PROF_DETAILS_DISABLED);
+  return sysprof_error(L, PROFILE_ERRUSE, err_details);
+#endif /* !LJ_HASSYSPROF */
+
   int status = PROFILE_SUCCESS;
 
   struct luam_Sysprof_Options opt = {};
-  const char *err_details = NULL;
 
   status = parse_sysprof_opts(L, &opt, &err_details);
   if (LJ_UNLIKELY(status != PROFILE_SUCCESS))
@@ -336,6 +341,11 @@ LJLIB_CF(misc_sysprof_start)
 /* local res, err, errno = profile.sysprof_stop() */
 LJLIB_CF(misc_sysprof_stop)
 {
+#if !LJ_HASSYSPROF
+  const char *err_details = NULL;
+  err_details = err2msg(LJ_ERR_PROF_DETAILS_DISABLED);

Looks like we just can do the following for this block:

| const char *err_details = err2msg(LJ_ERR_PROF_DETAILS_DISABLED);

Here and below.

+  return sysprof_error(L, PROFILE_ERRUSE, err_details);
+#endif /* !LJ_HASSYSPROF */
   int status = luaM_sysprof_stop(L);
   if (LJ_UNLIKELY(status != PROFILE_SUCCESS))
     return sysprof_error(L, status, NULL);
@@ -347,6 +357,11 @@ LJLIB_CF(misc_sysprof_stop)
 /* local counters, err, errno = sysprof.report() */
 LJLIB_CF(misc_sysprof_report)
 {
+#if !LJ_HASSYSPROF
+  const char *err_details = NULL;
+  err_details = err2msg(LJ_ERR_PROF_DETAILS_DISABLED);
+  return sysprof_error(L, PROFILE_ERRUSE, err_details);
+#endif /* !LJ_HASSYSPROF */
   struct luam_Sysprof_Counters counters = {};
   GCtab *data_tab = NULL;
   GCtab *count_tab = NULL;
@@ -386,6 +401,11 @@ LJLIB_CF(misc_sysprof_report)
 /* local started, err, errno = misc.memprof.start(fname) */
 LJLIB_CF(misc_memprof_start)
 {
+#if !LJ_HASMEMPROF
+  const char *err_details = NULL;
+  err_details = err2msg(LJ_ERR_PROF_DETAILS_DISABLED);
+  return sysprof_error(L, PROFILE_ERRUSE, err_details);
+#endif /* !LJ_HASMEMPROF */
   struct lj_memprof_options opt = {0};
   const char *fname = strdata(lj_lib_checkstr(L, 1));
   struct profile_ctx *ctx;
@@ -440,6 +460,11 @@ LJLIB_CF(misc_memprof_start)
 /* local stopped, err, errno = misc.memprof.stop() */
 LJLIB_CF(misc_memprof_stop)
 {
+#if !LJ_HASMEMPROF
+  const char *err_details = NULL;
+  err_details = err2msg(LJ_ERR_PROF_DETAILS_DISABLED);
+  return sysprof_error(L, PROFILE_ERRUSE, err_details);
+#endif /* !LJ_HASMEMPROF */
   int status = lj_memprof_stop(L);
   if (status != PROFILE_SUCCESS) {
     switch (status) {
diff --git a/src/lj_errmsg.h b/src/lj_errmsg.h
index b5c3a275..e26f5e38 100644
--- a/src/lj_errmsg.h
+++ b/src/lj_errmsg.h
@@ -193,6 +193,7 @@ ERRDEF(PROF_DETAILS_BADINTERVAL, "profiler interval must be greater than 1")
 ERRDEF(PROF_DETAILS_BADPATH, "profiler path does not exist")
 ERRDEF(PROF_DETAILS_BADTABLE, "profiler expects a table with parameters")
 
+ERRDEF(PROF_DETAILS_DISABLED, "profiler is disabled")

I suppose this should be declared under `#else` directive (i.e. if we
have at least one profiler disabled).

err message is required by code for checking disabled profilers (see above)

 #undef ERRDEF
 
 /* Detecting unused error messages:
diff --git a/test/tarantool-tests/profilers/misclib-memprof-lapi-disabled.test.lua b/test/tarantool-tests/profilers/misclib-memprof-lapi-disabled.test.lua
new file mode 100644
index 00000000..a0669cc6
--- /dev/null
+++ b/test/tarantool-tests/profilers/misclib-memprof-lapi-disabled.test.lua
@@ -0,0 +1,22 @@
+local tap = require("tap")

Please use single quotes everywhere across this file for the
consistency.

Fixed.

+local test = tap.test("misclib-memprof-lapi-disabled"):skipcond({
+  ["Memprof is enabled"] = not os.getenv('LUAJIT_DISABLE_MEMPROF'),
+})
+
+test:plan(6)
+
+-- Attempt to start memprof when memprof is disabled.

Minor: s/start memprof when memprof/start memprof when it/

+local res, err, errno = misc.memprof.start()
+test:is(res, nil, "result status on start when memprof is disabled")
+test:ok(err:match("profiler is disabled"),
+        "error on start when memprof is disabled")
+test:ok(type(errno) == "number", "errno on start when memprof is disabled")
+
+-- Attempt to stop memprof when memprof is disabled.

Minor: s/stop memprof when memprof/stop memprof when it/

+res, err, errno = misc.memprof.stop()
+test:is(res, nil, "result status on stop when memprof is disabled")
+test:ok(err:match("profiler is disabled"),
+        "error on stop when memprof is disabled")
+test:ok(type(errno) == "number", "errno on start when memprof is disabled")
+
+test:done(true)
diff --git a/test/tarantool-tests/profilers/misclib-sysprof-lapi-disabled.test.lua b/test/tarantool-tests/profilers/misclib-sysprof-lapi-disabled.test.lua
new file mode 100644
index 00000000..79707434
--- /dev/null
+++ b/test/tarantool-tests/profilers/misclib-sysprof-lapi-disabled.test.lua
@@ -0,0 +1,29 @@
+local tap = require("tap")

Please use single quotes everywhere across this file for the
consistency.

+local test = tap.test("misclib-sysprof-lapi-disabled"):skipcond({
+  ["Sysprof is enabled"] = not os.getenv('LUAJIT_DISABLE_SYSPROF'),
+})
+
+test:plan(9)
+
+-- Attempt to start sysprof when sysprof is disabled.
+local res, err, errno = misc.sysprof.start()
+test:is(res, nil, "result status on start when sysprof is disabled")
+test:ok(err:match("profiler is disabled"),
+        "error on start when sysprof is disabled")
+test:ok(type(errno) == "number", "errno on start when sysprof is disabled")
+
+-- Attempt to stop sysprof when sysprof is disabled.
+res, err, errno = misc.sysprof.stop()
+test:is(res, nil, "result status on stop when sysprof is disabled")
+test:ok(err:match("profiler is disabled"),
+        "error on stop when sysprof is disabled")
+test:ok(type(errno) == "number", "errno on start when sysprof is disabled")
+
+-- Attempt to report when sysprof is disabled.
+res, err, errno = misc.sysprof.report()
+test:is(res, nil, "result status on report when sysprof is disabled")
+test:ok(err:match("profiler is disabled"),
+        "error on stop when sysprof is disabled")
+test:ok(type(errno) == "number", "errno on start when sysprof is disabled")
+
+test:done(true)
-- 
2.34.1