Hojun-Cho
a376ec89eb
Hare's canonical runtime allocator is rt::malloc with linker symbol
rt.malloc (ref/hare/rt/malloc.ha:27,78). ww kept the dot→underscore
Plan 9 convention (CLAUDE.md rule 4) so the linker symbol becomes
rt_malloc; the lib/rt exported function name becomes malloc; ww
callers say rt.malloc(...).
The language builtin keyword stays `alloc(T)!` — unchanged from Hare
(ref/hare/hare/lex/token.ha:21 ltok::ALLOC, parse/expr.ha:398
builtin()). The rename only touches the lowered linker symbol and the
exported function name behind it; the user-facing syntax for
heap-allocation is identical to Hare.
Surface:
- rt/alloc.s: TEXT rt_alloc → TEXT rt_malloc, labels updated
- lib/rt/malloc.ww: @symbol("rt_malloc") fn malloc(...) (was rt_alloc/alloc)
- rt/ensure.ww: local FFI decl + call site updated to malloc; `!` dropped
on the direct FFI call (rt_malloc returns *void, not a tagged union)
- 18 .ww callers: rt.alloc(...) → rt.malloc(...)
- cstage cmd/wcc/check.c + wwstage selfhost/cmd/wcc/check.ww
alloc-builtin suppression gate routes through ffi_resolve("malloc")
for the lowering; the user-shadow check still keys on the BUILTIN
KEYWORD "alloc" since that is what `alloc(...)` parses as. Adding
"malloc" to the user-shadow check was unnecessary and was reverted
during pre-commit review.
- cstage cmd/w6c/cgen.c: 2× ffi_resolve("alloc") → ffi_resolve("malloc")
- wwstage cgenexpr/cgenstmt: 2× ffiresolve(c, "alloc") → ffiresolve(c, "malloc")
- Test fixtures (700_e2e, 758_cgalloc_str_field, 990_selfhost, 992_w6l_ww,
selfhost/test/tagged_ptr_ret.ww): updated inline ww sources to the new
decl + call form
This is commit 2 of 3 in the lib/rt extraction (#38). Commit 3 closes
the OOM contract — return type becomes nullable *void and the builtin
lowering null-checks + propagates nomem.
Verified 132/132 + 995_self_rebuild byte-identity (5 wwstage tools
round-trip identical) + make clean cold rebuild.
49 lines
2.1 KiB
ArmAsm
49 lines
2.1 KiB
ArmAsm
// rt/start.s — process entry. Linux sets up the stack so that on
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// entry [SP] holds argc, [SP+8] starts argv (NULL-terminated array
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// of *u8), [SP+8+(argc+1)*8] starts envp (also NULL-terminated).
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//
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// We pull argc into DI and the argv pointer into SI, then jump to
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// `main`. ww programs that declare `fn main(argc: i32, argv: **u8)
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// i32` see them; programs declaring `fn main() i32` simply ignore
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// the regs. Either way, main's return value is fed to the exit
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// syscall.
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//
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// envp is captured into the rt_envp_slot DATAW cell before CALL main
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// so lib/os.getenv (via the rt_envp getter below) can walk it. We
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// compute envp = SP + 16 + argc*8 in AX using three doublings and
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// adds — w6a's syntax doesn't ship SIB-style indexed addressing
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// (no `LEAQ 16(SP)(DI*8), AX`), so the explicit shift-by-three is
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// the portable form. AX/DI/SI are scratch on entry; no callee-
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// saved discipline applies until we reach main.
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TEXT _start,$0
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MOVQ (SP), DI // argc → DI (1st arg to main)
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LEAQ 8(SP), SI // &argv[0] → SI (2nd arg to main)
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MOVQ DI, AX // AX = argc
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ADDQ AX, AX // AX = argc * 2
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ADDQ AX, AX // AX = argc * 4
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ADDQ AX, AX // AX = argc * 8
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ADDQ SP, AX // AX = SP + argc*8
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ADDQ $16, AX // AX = SP + argc*8 + 16 = &argv[argc+1] = envp
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MOVQ AX, rt_envp_slot(SB)
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CALL main(SB)
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MOVQ AX, DI
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MOVQ $60, AX
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SYSCALL
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// rt_envp — getter that returns the envp pointer captured at process
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// entry. Bound from lib/os via `@symbol("rt_envp") fn rtenvp() **u8;`,
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// matching the rt_syscall / rt_malloc / rt_abort pattern. Read-only
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// view of the kernel-supplied table; the bytes live for the process
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// lifetime. A future setenv that grows the table re-points the slot
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// (separate task).
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TEXT rt_envp,$0
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MOVQ rt_envp_slot(SB), AX
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RET
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// rt_envp_slot — 8-byte writable cell holding the envp pointer.
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// Initialised to zero in .data; _start overwrites it before
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// transferring control to main. DATAW gives us the writable .data
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// slot (w6a has no GLOBL; same shape as lib/log's silent/default/
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// global cells in lib/log/log.s).
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DATAW rt_envp_slot(SB),"\x00\x00\x00\x00\x00\x00\x00\x00"
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