Using g_slice_set_config() fails with newer glib because the slice allocator
now has a static constructor that runs when glib is loaded, consequently
emitting a noisy error message which confuses people into believing it's the
root of their problems.
The only way left to force the slice allocator to use "system" malloc (in
practice, jemalloc) is to set the G_SLICE environment variable to
always-malloc, and that needs to happen before glib is loaded.
Fortunately, the firefox and plugin-container executables don't depend on
glib. Unfortunately, webapprt does, so the problem remains for web apps
running through it. xpcshell and other executables that depend on libxul
directly (as opposed to loading it dynamically) are not covered either.
Using g_slice_set_config() fails with newer glib because the slice allocator
now has a static constructor that runs when glib is loaded, consequently
emitting a noisy error message which confuses people into believing it's the
root of their problems.
The only way left to force the slice allocator to use "system" malloc (in
practice, jemalloc) is to set the G_SLICE environment variable to
always-malloc, and that needs to happen before glib is loaded.
Fortunately, the firefox and plugin-container executables don't depend on
glib. Unfortunately, webapprt does, so the problem remains for web apps
running through it. xpcshell and other executables that depend on libxul
directly (as opposed to loading it dynamically) are not covered either.
We build without UNICODE, so we end up calling the ANSI version
of the function, and then we would attempt to interpret the
resulting narrow char buffer as a wide char buffer.
Currently, when there is both an expandlibs descriptor and an actual static
library, expandlibs picks the static library. This has the side effect that
if there are object files in the static library that aren't directly used,
they're dropped when linking, even when they export symbols that would be
exported in the final linked binary.
In most cases in the code base, files are not dropped that way. The most
notable counter-example is xpcomglue, where actually not dropping files
leads to link failure because of missing symbols those files reference
(yes, that would tend to say the glue is broken in some way).
On the opposite side, there is mozglue, which does have both a descriptor
and a static library (the latter being necessary for the SDK), and that
linking as a static library drops files that shouldn't be dropped (like
jemalloc). We're currently relying on -Wl,--whole-archive for those files
not to be dropped, but that won't really be possible without much hassle
in a world where mozglue dependencies live in moz.build land.
Switching expandlibs to use descriptors when they exist, even when there
is a static library (so, the opposite of the current behavior) allows to
drop -Wl,--whole-archive and prepare for a better future. However, as
mentioned, xpcomglue does still require to be linked through the static
library, so we need to make it a static library only.
To achieve that, we make NO_EXPAND_LIBS now actually mean no expandlibs
and use that to build the various different xpcomglues.
Mike Hommey
Ted Mielczarek
Ganesh Sahukari
Chris Peterson
Brian Smith
Nicholas Nethercote
Ehsan Akhgari
Mark Banner
Stephen Pohl
Birunthan Mohanathas
Nathan Froyd
L. David Baron
Ms2ger
Cykesiopka
Joey Armstrong
Brian O'Keefe
Olli Pettay
Mike Shal
Benoit Girard
Phil Ringnalda
Kyle Machulis