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Less verbose logs from make#1

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xavierleroy merged 8 commits intoxavierleroy:less-verbose-makefrom
nojb:less-verbose-make
Jan 3, 2023
Merged

Less verbose logs from make#1
xavierleroy merged 8 commits intoxavierleroy:less-verbose-makefrom
nojb:less-verbose-make

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@nojb nojb commented Jan 3, 2023

I played around with your nice PR, stealing some ideas from the Emacs sources (where they do the same thing).

  • Instead of printing the input file (and, sometimes, the output file) of each rule, print only the output file (this is clear enough 99% of the time). This allows a uniform handling of all rules (just print $@).

  • Print trace lines with two leading spaces. This allows to quickly separate trace output from other types of outputs (make output, standard output of called programs, errors, etc).

  • Instead of calling $(info ...) explicitly, hide this call behind a variable $(V_XXX). Apart from sharing the strings that are printed, this also reduces the diff on the Makefile rules themselves: they can be written on the same line as the rule command, and it also hides the @ directive. See Makefile.common for the full list of variables (first commit).

  • Adapted many of the remaining uses. For linking commands I used LINKC and LINKOPT but we could use OCAMLC and OCAMLOPT as well. I used GEN as a fallback for several different kinds of rules that generate files.

  • I think we can live for now without differentiating between OCAMLC and OCAMLC.OPT, etc (but would be nice to add in a later PR).

There is still a bit of work to do to get 100% coverage, but this gets us much closer to the goal I think.

Attached is the log resulting from the above modifications:

log.txt

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Very nice, thanks a lot!

  • I thought about always printing the generated file ($@) but was afraid it would be harder to read than if the source file is printed. From your sample log it doesn't seem to be the case, so it's a welcome simplification.
  • The V_* macros are clever! And if we ever want to go back to the default printing of commands (perhaps based on a specific Make variable), it suffices to define the V_* macros to be empty, right?

@xavierleroy xavierleroy merged commit 7a92206 into xavierleroy:less-verbose-make Jan 3, 2023
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nojb commented Jan 3, 2023

  • The V_* macros are clever! And if we ever want to go back to the default printing of commands (perhaps based on a specific Make variable), it suffices to define the V_* macros to be empty, right?

Yes.

@nojb nojb deleted the less-verbose-make branch January 3, 2023 10:49
xavierleroy pushed a commit that referenced this pull request Aug 29, 2024
Found by -fsanitize=memory -fsanitize-memory-track-origins:
```
> ==102752==WARNING: MemorySanitizer: use-of-uninitialized-value
>     #0 0x7f2ba7fb4ea4 in caml_runtime_events_read_poll /var/home/edwin/git/ocaml/otherlibs/runtime_events/runtime_events_consumer.c:496:18
>     #1 0x7f2ba7fbc016 in caml_ml_runtime_events_read_poll /var/home/edwin/git/ocaml/otherlibs/runtime_events/runtime_events_consumer.c:1207:9
>     ocaml#2 0x59ba5c in caml_interprete /var/home/edwin/git/ocaml/runtime/interp.c:1058:14
>     ocaml#3 0x5a9220 in caml_main /var/home/edwin/git/ocaml/runtime/startup_byt.c:575:9
>     ocaml#4 0x540d6b in main /var/home/edwin/git/ocaml/runtime/main.c:37:3
>     ocaml#5 0x7f2ba8120087 in __libc_start_call_main (/lib64/libc.so.6+0x2a087) (BuildId: 8f53abaad945a669f2bdcd25f471d80e077568ef)
>     ocaml#6 0x7f2ba812014a in __libc_start_main@GLIBC_2.2.5 (/lib64/libc.so.6+0x2a14a) (BuildId: 8f53abaad945a669f2bdcd25f471d80e077568ef)
>     ocaml#7 0x441804 in _start (/var/home/edwin/git/ocaml/runtime/ocamlrun+0x441804) (BuildId: 617637580ee48eff08a2bce790e1667ad09f3b69)
>
>   Uninitialized value was stored to memory at
>     #0 0x7f2ba7fb4e9d in caml_runtime_events_read_poll /var/home/edwin/git/ocaml/otherlibs/runtime_events/runtime_events_consumer.c:497:69
>     #1 0x7f2ba7fbc016 in caml_ml_runtime_events_read_poll /var/home/edwin/git/ocaml/otherlibs/runtime_events/runtime_events_consumer.c:1207:9
>     ocaml#2 0x59ba5c in caml_interprete /var/home/edwin/git/ocaml/runtime/interp.c:1058:14
>     ocaml#3 0x5a9220 in caml_main /var/home/edwin/git/ocaml/runtime/startup_byt.c:575:9
>     ocaml#4 0x540d6b in main /var/home/edwin/git/ocaml/runtime/main.c:37:3
>     ocaml#5 0x7f2ba8120087 in __libc_start_call_main (/lib64/libc.so.6+0x2a087) (BuildId: 8f53abaad945a669f2bdcd25f471d80e077568ef)
>     ocaml#6 0x7f2ba812014a in __libc_start_main@GLIBC_2.2.5 (/lib64/libc.so.6+0x2a14a) (BuildId: 8f53abaad945a669f2bdcd25f471d80e077568ef)
>     ocaml#7 0x441804 in _start (/var/home/edwin/git/ocaml/runtime/ocamlrun+0x441804) (BuildId: 617637580ee48eff08a2bce790e1667ad09f3b69)
>
>   Uninitialized value was created by an allocation of 'buf' in the stack frame
>     #0 0x7f2ba7fb3dbc in caml_runtime_events_read_poll /var/home/edwin/git/ocaml/otherlibs/runtime_events/runtime_events_consumer.c:402:7
>
```

This is in fact an EV_LIFECYCLE with EV_RING_STOP, which has 0
additional data, and thus msg_length 2:
```
runtime/runtime_events.c:      EV_RUNTIME, (ev_message_type){.runtime=EV_LIFECYCLE}, EV_RING_STOP, 0,
```

Attempting to read from `buf[2]` would read uninitialized data.

Signed-off-by: Edwin Török <edwin.torok@cloud.com>
xavierleroy pushed a commit that referenced this pull request Aug 29, 2024
…l#13294)

The toplevel printer detects cycles by keeping a hashtable of values
that it has already traversed.

However, some OCaml runtime types (at least bigarrays) may be
partially uninitialized, and hashing them at arbitrary program points
may read uninitialized memory. In particular, the OCaml testsuite
fails when running with a memory-sanitizer enabled, as bigarray
printing results in reads to uninitialized memory:

```
==133712==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x4e6d11 in caml_ba_hash /var/home/edwin/git/ocaml/runtime/bigarray.c:486:45
    #1 0x52474a in caml_hash /var/home/edwin/git/ocaml/runtime/hash.c:251:35
    ocaml#2 0x599ebf in caml_interprete /var/home/edwin/git/ocaml/runtime/interp.c:1065:14
    ocaml#3 0x5a909a in caml_main /var/home/edwin/git/ocaml/runtime/startup_byt.c:575:9
    ocaml#4 0x540ccb in main /var/home/edwin/git/ocaml/runtime/main.c:37:3
    ocaml#5 0x7f0910abb087 in __libc_start_call_main (/lib64/libc.so.6+0x2a087) (BuildId: 8f53abaad945a669f2bdcd25f471d80e077568ef)
    ocaml#6 0x7f0910abb14a in __libc_start_main@GLIBC_2.2.5 (/lib64/libc.so.6+0x2a14a) (BuildId: 8f53abaad945a669f2bdcd25f471d80e077568ef)
    ocaml#7 0x441804 in _start (/var/home/edwin/git/ocaml/runtime/ocamlrun+0x441804) (BuildId: 7a60eef57e1c2baf770bc38d10d6c227e60ead37)

  Uninitialized value was created by a heap allocation
    #0 0x47d306 in malloc (/var/home/edwin/git/ocaml/runtime/ocamlrun+0x47d306) (BuildId: 7a60eef57e1c2baf770bc38d10d6c227e60ead37)
    #1 0x4e7960 in caml_ba_alloc /var/home/edwin/git/ocaml/runtime/bigarray.c:246:12
    ocaml#2 0x4e801f in caml_ba_create /var/home/edwin/git/ocaml/runtime/bigarray.c:673:10
    ocaml#3 0x59b8fc in caml_interprete /var/home/edwin/git/ocaml/runtime/interp.c:1058:14
    ocaml#4 0x5a909a in caml_main /var/home/edwin/git/ocaml/runtime/startup_byt.c:575:9
    ocaml#5 0x540ccb in main /var/home/edwin/git/ocaml/runtime/main.c:37:3
    ocaml#6 0x7f0910abb087 in __libc_start_call_main (/lib64/libc.so.6+0x2a087) (BuildId: 8f53abaad945a669f2bdcd25f471d80e077568ef)
    ocaml#7 0x7f0910abb14a in __libc_start_main@GLIBC_2.2.5 (/lib64/libc.so.6+0x2a14a) (BuildId: 8f53abaad945a669f2bdcd25f471d80e077568ef)
    ocaml#8 0x441804 in _start (/var/home/edwin/git/ocaml/runtime/ocamlrun+0x441804) (BuildId: 7a60eef57e1c2baf770bc38d10d6c227e60ead37)

SUMMARY: MemorySanitizer: use-of-uninitialized-value /var/home/edwin/git/ocaml/runtime/bigarray.c:486:45 in caml_ba_hash
```

The only use of hashing in genprintval is to avoid cycles, that is, it
is only useful for OCaml values that contain other OCaml values
(including possibly themselves). Bigarrays cannot introduce cycles,
and they are always printed as "<abstr>" anyway.

The present commit proposes to be more conservative in which values
are hashed by the cycle detector to avoid this issue: we skip hashing
any value with tag above No_scan_tag -- which may not contain any
OCaml values.

Suggested-by: Gabriel Scherer <gabriel.scherer@gmail.com>

Signed-off-by: Edwin Török <edwin.torok@cloud.com>
Co-authored-by: Edwin Török <edwin.torok@cloud.com>
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