* Revert "[strip -ST] Disable runtime stack trace dumping on Darwin when asserts are disabled."
This reverts commit 6bc28ff1c9.
* Bring back important fixes from the revert of 6bc28ff1c9.
* Change swift::swift_reportError to only print the backtrace in assert builds (swift::warning prints backtrace always).
This commit disables runtime stack trace dumping via dladdr on Darwin when
asserts are disabled.
This stack trace dumping was added as a way to improve the ability to debug the
compiler for compiler developers. This is all well and good but having such a
feature always enabled prevents us from reducing the size of the swift standard
library by eliminating the swift nlist.
rdar://31372220
- Win32 does not support dlfcn.h, Dl_info or dladdr() so add
lookupSymbol() as a wrapper for ELF/MachO/Win32
- Win32 version needs an implementation, currently it just returns
an error for `cannot lookup address'
The code we use to interface with the platform dynamic linker is turning into a rat's nest of conditionals that's hard to maintain and extend. Since ELF, Mach-O, and PE platforms have pretty fundamentally different dynamic linker interfaces and capabilities, it makes sense to factor that code into a separate file per-platform, instead of trying to conditionalize the logic in-line. This patch factors out a much simpler portable interface for lazily kicking off the protocol conformance and type metadata lookup caches, and factors the guts out into separate MachO, ELF, and Win32 backends. This should also be a much cleaner interface to interface static binary behavior into, assisting #5349.
