784620 - Support compiling JS in self-hosting mode in the shell

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Till Schneidereit [:till]]

This would enable testing self-hosted code without recompiling the shell.

Comment 1

[Till Schneidereit [:till]]

Attachment: v1

So it occurred to me that making it possible to load an external JS file during runtime and to set that file using an environment variable is more useful than adding a special compile mode to the shell.

This patch adds the environment variable "MOZ_SELFHOSTEDJS" and changes the makefile and embedjs.py script very slightly to make creating the required JS file easier.

Usage:
1. modify any JS file that's compiled into selfhosted.js
2. invoke the shell or the browser with "MOZ_SELFHOSTEDJS=./selfhosted.js ./js" (for the shell, in the obj dir) or "MOZ_SELFHOSTEDJS=[path to js obj dir].selfhosted.js ./run-mozilla.sh ./firefox" (for the browser, in the dist/bin dir)

Comment 2

[Luke Wagner [:luke]]

Comment on attachment 663833 [details] [diff] [review]
v1

Punting to Terrence.

Comment 3

[Terrence Cole [:terrence]]

Comment on attachment 663833 [details] [diff] [review]
v1

Review of attachment 663833 [details] [diff] [review]:
-----------------------------------------------------------------

LGTM

Comment 4

[Till Schneidereit [:till]]

Attachment: v2

rebased, pushed to try here:
http://tbpl.mozilla.org/?tree=Try&rev=b0e52a4a5627

Comment 5

[Till Schneidereit [:till]]

Comment on attachment 663833 [details] [diff] [review]
v1

hrmpf

Comment 6

[Till Schneidereit [:till]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/5f1d0cfe99ac

Comment 7

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/5f1d0cfe99ac

Comment 8

[:Ms2ger (he/him; ⌚ UTC+1/+2)]

Comment on attachment 670367 [details] [diff] [review]
v2

Review of attachment 670367 [details] [diff] [review]:
-----------------------------------------------------------------

::: js/src/jscntxt.cpp
@@ +272,5 @@
> +    char *filename = getenv("MOZ_SELFHOSTEDJS");
> +    if (filename) {
> +        RootedScript script(cx, Compile(cx, shg, options, filename));
> +        if (script)
> +            ok = Execute(cx, script, *shg.get(), &rv);

So if script is null, we will return some uninitialized value?

Comment 9

[Till Schneidereit [:till]]

(In reply to :Ms2ger from comment #8)
> So if script is null, we will return some uninitialized value?

Thanks for noticing. Luckily, Ehsan fixed that in bug 801344.