Cannot add 'JS_STRUCTURED_SPEW' to configuration: Key already exists

[leeN]

If I have ac_add_options --enable-jitspew in my .mozconfig, the build will fail with the following error:

0:06.97 checking bindgen cflags... -x c++ -fno-sized-deallocation -fno-aligned-new -DTRACING=1 -DIMPL_LIBXUL -DMOZILLA_INTERNAL_API -DRUST_BINDGEN --sysroot /home/taintfox/.mozbuild/sysroot-x86_64-linux-gnu
 0:06.97 Traceback (most recent call last):
 0:06.97   File "/mnt/storage/taintfox/project-foxhound/configure.py", line 351, in <module>
 0:06.97     sys.exit(main(sys.argv))
 0:06.97              ^^^^^^^^^^^^^^
 0:06.98   File "/mnt/storage/taintfox/project-foxhound/configure.py", line 141, in main
 0:06.98     sandbox.run()
 0:06.98   File "/mnt/storage/taintfox/project-foxhound/python/mozbuild/mozbuild/configure/__init__.py", line 573, in run
 0:06.98     func(*args)
 0:06.98   File "/mnt/storage/taintfox/project-foxhound/python/mozbuild/mozbuild/configure/__init__.py", line 1125, in _resolve_and_set
 0:06.98     raise ConfigureError(
 0:06.98 mozbuild.configure.ConfigureError: Cannot add 'JS_STRUCTURED_SPEW' to configuration: Key already exists
*** Fix above errors and then restart with "./mach build"

I assume this is related to the TaintSpewing changeset in PR #242. This failed the automated build for the binaries, oops.

I can try to have a look next week on how we can keep jitspewing an option while allowing taints to be spewed as well.

[leeN]

I think the issue is that we define JS_STRUCTURED_SPEW twice.

set_define("JS_STRUCTURED_SPEW", depends_if("--enable-jitspew")(lambda _: True))
set_config("JS_STRUCTURED_SPEW", depends_if("--enable-jitspew")(lambda _: True))

option(
    "--enable-taintspew",
    default=False,
    help="{Enable|Disable} the taint flow spew variable",
)

# Also enable the structured spewer for tainting
set_define("JS_STRUCTURED_SPEW", depends_if("--enable-taintspew")(lambda _: True))
set_config("JS_STRUCTURED_SPEW", depends_if("--enable-taintspew")(lambda _: True))

Maybe it can be selectively enabled like this

[tmbrbr]

Good catch, I didn't test both configuration options together.

Having an option to enable both flags would be great.

On the other hand, perhaps we don't need a dedicated --enable-taintspew flag at all? At the moment both flags provide the same functionality, and only the JS_STRUCTURED_SPEW flag is ever checked in the code.

[leeN]

Considering that whether we spew anything is controlled via environment variables, it may be easiest to remove the said flag. Agreed.