Blaise now runs natively on FreeBSD and compiles+links working FreeBSD binaries
(fork/exec RTL sub-compiles, threaded incremental workers, internal assembler +
linker, freestanding runtime), and cross-compiles both directions (Linux<->
FreeBSD). Each of these was a real FreeBSD-only runtime bug exposed by running on
a real FreeBSD 14.3 kernel — invisible to host-side static checks:
* fork(2) child return: FreeBSD returns the child in %rax=parent-pid with
%edx=1 (child indicator); the raw leaf must zero %eax when %edx!=0, else the
forked child runs the parent branch and never execve's its target (exit 127).
* thread join teardown: the worker set its join word + umtx-WAKE while still on
its own stack, so pthread_join munmap'd the shared stack/CB region out from
under the still-live thread -> SIGSEGV. Fixed by passing the join word as
thr_exit(state): the kernel does the suword+umtx-wake AFTER the thread leaves
its stack, so the joiner only wakes once the stack is safe to free.
* argc stack pad word: FreeBSD 16-aligns the entry %rsp and inserts a zero pad
word below argc when the argv+envc pointer-count parity requires it, so argc
is at [rsp] or [rsp+8]. _BlaiseStartC now detects and skips the pad word;
previously an execve'd child with a different environment read the pad (0) as
argc and reported "--source is required".
Target-driven OS conditional compilation (self-hosting requires HostTarget to be
correct on the produced binary):
* The OS defines (LINUX/FREEBSD/WINDOWS/UNIX) now follow the resolved --target,
not the compiler's build host. SeedPredefines seeds the host OS as a default
(keeps direct-lexer callers/tests working) via compile-time IFDEF; the driver
injects the target's OS symbol and AddDefinesTo / the unit loader replace the
host-seeded OS symbols with it on every lexer (program + dep units).
* HostTarget() reads {$IFDEF FREEBSD} etc., so a blaise built with
--target freebsd bakes HostTarget=osFreeBSD — a FreeBSD-hosted blaise then
defaults (no --target) to producing FreeBSD binaries. Verified both
directions on the VM.
Usability:
* blaise.cfg now supports rtl-src=<dir> (relative resolved against the config
dir); a CLI --rtl-src overrides it. So a relocated binary can drop a
blaise.cfg with unit-path= + rtl-src= and need no path flags. Tests:
TConfigTests.TestParseRtlSrc_*.
* --help documents the previously-undocumented --rtl-src flag and the
blaise.cfg keys, and the --target line now shows the ACTUAL host default
(TargetName(HostTarget())) instead of a hardcoded linux-x86_64 — correct on
every host.
Verified: all four fixpoints green; full suite 4032 tests under QBE-built and
native-built runner; Linux self-host and Linux<->FreeBSD cross-compile confirmed;
FreeBSD self-host (blaise compiling+running a program) confirmed on FreeBSD 14.3.
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