Struct members can be `struct { ... }` (anonymous nested) or a bare
named type, in addition to `name: type`. The inner struct's fields
are promoted to the outer scope with offsets shifted by the embed
base; codegen already keys off Tfield.offset so cgen needs no change.
Errors on non-struct embed or name collision.
`e is T` returns bool (variant tag == T's index); `e as T` unwraps
to T or exit(1) on mismatch. Postfix, same precedence as `:` cast.
TK_IS / N_TYPETEST / N_TYPEASSERT appended at the tail of their
enums so every prior numeric value stays unchanged — the
990_selfhost wwdump-diff stays byte-clean.
Cgen mirrors the match-case slot-based load (tag at +0, value at
+8/+16), so an N_IDENT tagged-union local works just like a
match scrutinee. Selfhost cgen inlines the slot resolution
because the wwstage cgen drops sign bits on `*i32` output
parameters in this position.
Renames `errors.is` -> `errors.equal` (the only naming collision;
the existing comment already noted it shared shape with
strings.equal/bytes.equal).
Plan 9-style w-prefix on the per-arch tools, disambiguating from the
real Plan 9 6c/6a/6l in ref/plan9front/:
cmd/wwc/ → cmd/wcc/ libwwc.a → libwcc.a
cmd/6{c,a,l} → cmd/w6{c,a,l} binary names too
test/wwc/ → test/wcc/ 6 test files w/ w6 prefix
selfhost/cmd mirror in lockstep
bootstrap/amd64/{w6c,w6a,w6l} snapshot binaries (gitignored)
WW_6{C,A,L} → WW_W6{C,A,L} env-var overrides
Plan 9 source-tree refs ("Plan 9 6c shape", ref/plan9front/, etc.)
preserved. Hare-style driver, both C and ww sides:
ww test [path] discover *_test.ww in a directory module, run
each; single-file mode for `ww test foo.ww`
Module-by-name `ww build foo` resolves to foo.ww or foo/foo.ww
via search path (cwd : -I dirs : $WW_LIB)
Default-to-cwd `ww build` / `ww test` build the cwd module
Run pass-through `ww run path arg1 arg2` reaches the program
lib/os: getcwd (79) and getdents64 (217) syscalls power `.` resolution
and directory enumeration on the ww side.
Makefile: wwstage tool deps now include lib/os/os.ww (+ lib/strconv
for wwdump_ww) so lib/* edits force their rebuild instead of leaving
stale binaries — surfaced when test 995 first failed against a stale
w6c_ww built before the lib/os additions.
Test 993 byte-identical parity gate (C-side ww vs ww-side ww_ww on a
build corpus) stays green; all 19 tests pass.
Ports cmd/6l/{dyn,dynout}.c into selfhost/cmd/6l/{dyn,dynout}.ww:
ET_DYN .so loading + PT_INTERP/PT_DYNAMIC ELF emission with .rela.plt,
.gnu.version_r, BIND_NOW. lsym grows dyn fields; pass.ww promotes
undefs to dyn; out.ww dispatches; main.ww takes -L/-l. The ww driver
forwards -L/-l to 6l_ww so 'ww_ww build snake.ww -L /usr/lib -l ncurses
-l c' runs without cc.
Test 996 pins byte-identical output to C-6l on snake.
'make bootstrap' gains a fourth stage with cmp ww3 == ww4, proving
ww3 is byte-stable when used as a compiler — not just a coincidental
two-stage equilibrium.
Four wwstage 6c cgen quirks surfaced and are documented in dynout.ww's
header (two-level field-write through a pointer field, (scalar, str)
tuple returns, def : str, ≤6 arg calling convention).
Drives ww_ww (which already shells to 6c_ww/6a_ww/6l_ww) over each
wwstage tool's source and diffs the resulting binary against the
cstage-built canonical in $BIN. A green run means the toolchain
can recompile itself end-to-end without invoking cc, modulo the
cold-start binary that brings the wwstage into existence.
Stricter than `make bootstrap`: that loop pins wwdump's cgen
self-stabilising; this pins all five wwstage tools (6c, 6a, 6l,
ww, wwdump) round-tripping through the wwstage pipeline.
The .combined.ww refreshes are the expander picking up the
parser/cgen changes from the prior commit. selfhost/cmd/6c/
gains its main.combined.ww for the first time — 995 builds it,
994 reads it.
selfhost/cmd/6c/main.ww is a thin packaging of the wwc cgen — slurp
a .ww file, run lex+parse+cgen, write Plan 9 amd64 asm to the path
given by -o. The cgen routines in selfhost/cmd/wwc/cgen.ww write
directly to fd 1, so we use dup2 to redirect stdout into the
output file rather than thread an fd through every emit helper.
Adds the SYS_DUP2=33 wrapper in lib/os.
Makefile wires $(BIN)/6c_ww alongside the other wwstage tools and
adds $(BIN)/test_6c_ww to the TESTS list.
test/wwc/994_6c_ww.c diffs 6c_ww byte-for-byte against
`wwdump_ww -c` on five in-source programs plus the four selfhost
main.combined.ww files: same cgen reached through two binaries, so
any divergence is a packaging bug in selfhost/cmd/6c.
We deliberately don't diff against C-side 6c here — 990 probe 5
already covers that on the subset the ww cgen handles today.
Teach the linker to consume ET_DYN shared objects and emit a
dynamically-linked ELF executable. Snake et al. can now link
against libncurses + libc through the system dynamic loader.
Pipeline additions:
- dyn.c: read ET_DYN, parse .dynsym + DT_SONAME, walk
.gnu.version_d / .gnu.version to learn each export's default
version (skip hidden entries).
- pass.c: when an undefined sym is provided by some Lso,
promote it to dynamic, assign a PLT slot, record the
matched version on the Lsym.
- dynout.c: emit PT_INTERP + PT_DYNAMIC, .dynsym/.dynstr/.hash,
.plt + .got.plt + .rela.plt, .gnu.version + .gnu.version_r,
and the full DT_* set with DT_BIND_NOW. Patch PC32/PLT32
references against dyn syms to point at their PLT stubs.
- main.c: -L<dir> and -l<name> flag parsing; resolve <name>
via .so / .so.<N> / .a in libdir order, skipping GNU ld
linker scripts (libc.so on most distros).
- ww driver: collect -l/-L (joined and split forms) and pass
through to 6l.
Design choices:
- DT_BIND_NOW so the loader resolves all PLT slots at startup;
no PLT0 lazy resolver stub.
- SysV .hash, not .gnu.hash. One bucket; loader scans the
chain. Slow at scale, fine for snake-class binaries.
- Non-PIE at fixed 0x400000.
- No section headers — loader uses program headers, but
readelf -V/-S won't display anything.
Symbol versioning is the only correctness item beyond the
basic PLT/GOT machinery: glibc symbols default to versions
later than GLIBC_2.2.5 (e.g. clock_gettime → GLIBC_2.17 for
the vDSO impl), and the loader rejects unversioned references
to those without a matching Vernaux entry.
test/wwc/810_dyn covers four cases: bare libc dyn call,
multi-PLT, clock_gettime versioning, and fn-pointer to FFI
binding (which exercises the codegen fixes from the parent
commit alongside the new linker path).
Three N_BIN/N_IDENT/N_CALL sites missed cases that bit ncurses
demos and dyn-linker exercises:
- Float compare emitted CMPQ + signed Jcc on f64 bits. Now goes
through UCOMISD/UCOMISS + the unsigned Jcc family, mirroring
Plan 9 6c (txt.c around AUCOMISD).
- LEAQ-of-fn-ident (taking the address of a function as a value)
used n->str without ffi_resolve, so binding a *fn from an
@symbol("name") fn declaration produced a reference to the
ww ident rather than the C symbol.
- N_CALL on a bare ident with no localfind hit was a direct
CALL ident(SB). Now checks localfind first and indirects
through AX when the callee names a local fn-pointer slot.
Hare/QBE handles both shapes the same way (sort/search.ha:15
calls cmp(...) where cmp is a *cmpfunc parameter).
