1933011 - --enable-warnings-as-errors and --disable-unified-build causes -Werror=unreachable-code in modules/libmar/verify/mar_verify.c

Status: RESOLVED FIXED

(Toolkit :: Application Update, defect)

Description

[Kelsey Gilbert [:jgilbert]]

 4:53.74 /git/gecko1/modules/libmar/verify/mar_verify.c:143:5: error: code will never be executed [-Werror,-Wunreachable-code]
 4:53.74   143 |     fprintf(stderr, "ERROR: Could not init crytpo library.\n");
 4:53.74       |     ^~~~~~~
 4:53.74 1 error generated.

Comment 1

[Kelsey Gilbert [:jgilbert]]

Attachment: Bug 1933011 - Fix -Werror=unreachable in libmar.

With:
--enable-warnings-as-errors
--disable-unified-build

 4:53.74 /git/gecko1/modules/libmar/verify/mar_verify.c:143:5: error: code will never be executed [-Werror,-Wunreachable-code]
 4:53.74   143 |     fprintf(stderr, "ERROR: Could not init crytpo library.\n");
 4:53.74       |     ^~~~~~~
 4:53.74 1 error generated.

So convert the macro to function, which makes the compiler happy.

Comment 2

[Kelsey Gilbert [:jgilbert]]

Attachment: Bug 1933011 - s/crytpo/crypto/.

Comment 3

[Max Christian Pohle [:/dev/max]]

Hi Kelsey! For the context: Can you please link the code to the issue causing unreachable lines or has there been a recent CI enforcement of avoiding unreachable code and can we link that bug where it was introduced?

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/e06aae14caf6
Fix -Werror=unreachable in libmar. r=sylvestre
https://hg.mozilla.org/integration/autoland/rev/600681873cdb
s/crytpo/crypto/. r=sylvestre,geckoview-reviewers,m_kato

Comment 5

[Kelsey Gilbert [:jgilbert]]

(In reply to Max Christian Pohle [:/dev/max] from comment #3)

Hi Kelsey! For the context: Can you please link the code to the issue causing unreachable lines or has there been a recent CI enforcement of avoiding unreachable code and can we link that bug where it was introduced?

This is not CI, this is on my local linux machine. My best guess is that we only build CI with either --enable-warnings-as-errors xor --disable-unified-build, but never both.

It is kinda suspect that this causes issues with non-unified builds, because that probably means there's a #define or #ifdef interaction that's happening differently in the two builds. However, I need to leave this investigation to a code owner. (FYI @sylvestre)

Comment 6

[Kelsey Gilbert [:jgilbert]]

Actually wait, you are the triage owner! I'm happy to help you try to replicate it for yourself! But you should merely need to build on Linux with those two options in your .mozconfig.

Here is my complete .mozconfig though:

[gitsh@duat gecko1]$ cat .mozconfig
ac_add_options --disable-debug
ac_add_options --disable-optimize
ac_add_options --enable-warnings-as-errors

ac_add_options --enable-debug
#ac_add_options --enable-optimize
ac_add_options --disable-unified-build

[gitsh@duat gecko1]$

Comment 7

[Norisz Fay [:noriszfay]]

https://hg.mozilla.org/mozilla-central/rev/e06aae14caf6
https://hg.mozilla.org/mozilla-central/rev/600681873cdb