Add new simple export mechanism #22977
Conversation
|
@brendandahl FYI still WIP |
sbc100
force-pushed
the
mangled_symbols
branch
2 times, most recently
from
e5e4d41 to
0cb2571
Compare
This change adds a new `-sEXPORT` setting that can by used to export any type of symbols (see emscripten-core#8380) It also includes a new `-sMANGLED_SYMBOLS` setting which default to true in order to not break backwards compatibility. Both these new settings are currently experimental and using `-sEXPORT` currently disables `-sMANGLED_SYMBOLS` by default.
sbc100
force-pushed
the
mangled_symbols
branch
from
0cb2571 to
3558467
Compare
| @@ -26,7 +26,7 @@ Module['thisProgram'] = 'thisProgram'; // for consistency between different buil | |||
|
|
|||
| function hashMemory(id) { | |||
| var ret = 0; | |||
| var len = _sbrk(0); | |||
| var len = sbrk(0); | |||
There was a problem hiding this comment.
How does this work? I was thinking that MANGLED_SYMBOLS controls whether we have _sbrk or sbrk, so how can this code have only one of the two forms?
There was a problem hiding this comment.
The idea is that internally the unmangled symbols are always available and ever present.
If somebody wants unmangled symbols they are generated in addition. I'm hoping DCE should take care the most of the cost of this.
If we didn't do it this way then all of these internal call sites would somehow have to be conditional, which seem like a bad idea.
There was a problem hiding this comment.
I see. Yeah, that makes sense. If we verify that JS optimizations remove the duplicate, then sgtm.
| }, | ||
| h: function() { | ||
| return n | 0; | ||
| } |
There was a problem hiding this comment.
These three new functions are maybe worth looking into. The first and last should be getting inlined, surely.
Perhaps we can add a tiny Acorn pass to deduplicate the mangled/unmangled globals, if they are the cause of this, and if Closure is not good enough to do it itself.
|
Looks good so far! I imagine this will bitrot very quickly. I'm happy to look into failures next week if you want help. |
|
This change adds a new
-sEXPORTsetting that can by used to export any type of symbols (see #8380)It also includes a new
-sMANGLED_SYMBOLSsetting which default to true in order to not break backwards compatibility.Both these new settings are currently experimental and using
-sEXPORTcurrently disables-sMANGLED_SYMBOLSby default.