selfhost/cmd/w6l: strip *arena cascade (γ-4)

amalloc has 0 callers post-γ-2; the *arena threaded through w6l's
mklnk/resolvelib/cstrtostr/elfglobals/dcstrtostr and the lnk.a
field are vestigial.

Drop `import mem;` from sym/main/obj/dyn/dynout, remove lnk.a
struct field, strip *arena from the five signatures, update 13
call sites. Drop a dead `let a: *arena = l.a;` in dynout. Comments
at pass.ww/obj.ww/main.ww retidied to match post-strip reality.
main.combined.ww auto-regenerated.

Verified 132/132 incl. 992_w6l_ww + 996_dyn_ww + 995_self_rebuild
byte-identity.

selfhost/cmd/w6l/dyn.ww

@@ -12,7 +12,6 @@ package w6l;
 
 import os;
 import rt;
-import mem;
 import strings;
 import sym;
 
@@ -107,7 +106,7 @@ fn dcstrlen(p: *u8) u64 = {
 	return n;
 };
 
-fn dcstrtostr(a: *arena, p: *u8) str = {
+fn dcstrtostr(p: *u8) str = {
 	let n: u64 = dcstrlen(p);
 	let view: str;
 	view.ptr = p;
@@ -295,7 +294,7 @@ export fn loadso(l: *lnk, path: *u8) i32 = {
 
 	// Build the lso. Exports are appended in dynsym order so
 	// soprovides_v's first-match semantics match the C version.
-	let so: *lso = alloc(lso { path = dcstrtostr(l.a, path), soname = dcstrtostr(l.a, sonamecs) })!;
+	let so: *lso = alloc(lso { path = dcstrtostr(path), soname = dcstrtostr(sonamecs) })!;
 	let tail: *lexport = nil;
 
 	let si: u64 = 1u64;
@@ -347,9 +346,9 @@ export fn loadso(l: *lnk, path: *u8) i32 = {
 			};
 
 			if (keep != 0) {
-				let e: *lexport = alloc(lexport { name = dcstrtostr(l.a, nmp) })!;
+				let e: *lexport = alloc(lexport { name = dcstrtostr(nmp) })!;
 				if (vernamecs != nil) {
-					e.version = dcstrtostr(l.a, vernamecs);
+					e.version = dcstrtostr(vernamecs);
 				};
 				if (tail == nil) {
 					so.exports = e;

selfhost/cmd/w6l/dynout.ww

@@ -26,7 +26,6 @@ package w6l;
 
 import os;
 import rt;
-import mem;
 import sym;
 
 // ELF constants
@@ -170,7 +169,6 @@ export fn emitdynelf(l: *lnk, fd: i32, base: u64, entry: u64) i32 = {
 	// Placed after .dynamic so the segment is one contiguous run;
 	// relocate runs from here so the dyn layout's datava lands in
 	// patched offsets.
-	let a: *arena = l.a;
 	let n: i32 = l.dynn;
 	let nu: u64 = n: u64;
 

selfhost/cmd/w6l/main.combined.ww

@@ -750,98 +750,6 @@ package rt;
 // a future task (task #39). ref/hare/rt/malloc.ha:27.
 @symbol("rt_malloc") export fn malloc(n: u64) *void;
 
-// selfhost/cmd/wcc/mem.ww — port of cmd/wcc/mem.c.
-//
-// Bump arena allocator. Backed by the runtime page allocator
-// (rt_malloc / rt_free), no libc. Each chunk is mmap'd; when the
-// current chunk runs out we link a fresh one. Freeing the arena
-// unmaps the chain.
-//
-// Memory handed out is 16-byte aligned. The C version under
-// cmd/wcc/ is retained until the three-stage bootstrap diffs clean.
-
-package wcc;
-
-import os;
-import rt;
-
-def ALIGN: u64       = 16u64;
-def INIT_CHUNK: u64  = 65536u64;
-def MAX_CHUNK: u64   = 4194304u64;
-def ARENA_SZ: u64    = 48u64;	// sizeof(arena), kept in sync below
-
-type arena = struct {
-	buf:   *u8,
-	off:   u64,
-	cap:   u64,
-	next:  *arena,
-	total: u64,
-};
-
-fn roundup(n: u64, a: u64) u64 = {
-	return (n + a - 1u64) & ~(a - 1u64);
-};
-
-export fn newarena() *arena = {
-	let a: *arena = rt.malloc(ARENA_SZ): *arena;
-	a.buf = rt.malloc(INIT_CHUNK): *u8;
-	a.off = 0u64;
-	a.cap = INIT_CHUNK;
-	a.next = nil;
-	a.total = 0u64;
-	return a;
-};
-
-// Grow: link a fresh chunk in front of the head. We push the old
-// chunk into `next` so the head always describes the current bump
-// region. Chunk size doubles up to MAX_CHUNK.
-fn grow(a: *arena, need: u64) bool = {
-	let want: u64 = a.cap * 2u64;
-	if (want < need) { want = need; };
-	if (want > MAX_CHUNK) { want = MAX_CHUNK; };
-	if (want < need) { return false; };	// single allocation too big
-
-	let old: *arena = rt.malloc(ARENA_SZ): *arena;
-	old.buf = a.buf;
-	old.off = a.off;
-	old.cap = a.cap;
-	old.next = a.next;
-	old.total = 0u64;
-
-	a.buf = rt.malloc(want): *u8;
-	a.off = 0u64;
-	a.cap = want;
-	a.next = old;
-	return true;
-};
-
-export fn amalloc(a: *arena, n: u64) *void = {
-	let need: u64 = roundup(n, ALIGN);
-	if (need > a.cap - a.off) {
-		if (!grow(a, need)) { return nil; };
-	};
-	let p: *u8 = a.buf + a.off;
-	a.off += need;
-	a.total += need;
-	// Zero the region. Plan 9 amalloc zeroes; we mirror that here so
-	// the checker can assume freshly allocated nodes start at 0.
-	let i: u64 = 0u64;
-	for (i < need) {
-		p[i] = 0u8;
-		i += 1u64;
-	};
-	return p: *void;
-};
-
-export fn freearena(a: *arena) void = {
-	for (a != nil) {
-		let next: *arena = a.next;
-		os.free(a.buf: *void, a.cap);
-		os.free(a: *void, ARENA_SZ);
-		a = next;
-	};
-};
-
 // selfhost/cmd/w6l/sym.ww — port of cmd/w6l/sym.c.
 //
 // Linker symbol table. Singly-linked list, usually a few hundred
@@ -849,8 +757,6 @@ export fn freearena(a: *arena) void = {
 
 package w6l;
 
-import mem;
-
 type lsym = struct {
 	name:        str,
 	val:         u64,	// offset within combined .text (or .data when
@@ -907,7 +813,6 @@ type lso = struct {
 };
 
 type lnk = struct {
-	a:       *arena,
 	objs:    *lobj,
 	sos:     *lso,
 	syms:    *lsym,
@@ -2899,7 +2804,6 @@ package w6l;
 
 import os;
 import rt;
-import mem;
 import strings;
 import sym;
 
@@ -3045,7 +2949,7 @@ fn cstrlen(p: *u8) u64 = {
 	return n;
 };
 
-// pathstr — view a NUL-terminated *u8 as a str. Bridges argv/arena
+// pathstr — view a NUL-terminated *u8 as a str. Bridges argv-style
 // callers to lib/os entrypoints (str post-task-#23). Shared with
 // main.ww and dyn.ww via the w6l bundle.
 fn pathstr(p: *u8) str = {
@@ -3068,7 +2972,7 @@ fn cstreq(p: *u8, lit: str) bool = {
 };
 
 // Build a ww str from a NUL-terminated *u8 (for passing to intern).
-fn cstrtostr(a: *arena, p: *u8) str = {
+fn cstrtostr(p: *u8) str = {
 	let n: u64 = cstrlen(p);
 	let view: str;
 	view.ptr = p;
@@ -3088,7 +2992,7 @@ type defent = struct {
 };
 
 type armember = struct {
-	data:   *u8,		// arena copy of the member's ELF bytes
+	data:   *u8,		// owned heap copy of the member's ELF bytes
 	size:   u64,
 	defs:   *defent,	// linked list of defined globals
 	loaded: i32,
@@ -3123,9 +3027,9 @@ fn arfield(p: *u8, n: u64) u64 = {
 };
 
 // elfglobals — return a linked list of names of globally-defined
-// (STB_GLOBAL) symbols whose section is `.text`. Names are arena
+// (STB_GLOBAL) symbols whose section is `.text`. Names are owned
-// copies, so the source ELF buffer can be freed afterward.
+// heap copies, so the source ELF buffer can be freed afterward.
-fn elfglobals(a: *arena, buf: *u8, len: u64) *defent = {
+fn elfglobals(buf: *u8, len: u64) *defent = {
 	if (len < EHDR_SIZE) { return nil; };
 	if (buf[0u64] != 127u8) { return nil; };
 	if (buf[1u64] != 69u8)  { return nil; };
@@ -3189,7 +3093,7 @@ fn elfglobals(a: *arena, buf: *u8, len: u64) *defent = {
 				if (intext || indt) {
 					let nmp: *u8 = strtab + (stname: u64);
 					if (nmp[0u64] != 0u8) {
-						let nm: str = cstrtostr(a, nmp);
+						let nm: str = cstrtostr(nmp);
 						let de: *defent = alloc(defent { name = nm, dnext = head })!;
 						head = de;
 					};
@@ -3242,7 +3146,7 @@ fn loadarchive(l: *lnk, path: *u8, buf: *u8, len: u64) i32 = {
 				i += 1u64;
 			};
 			m.data = mb;
-			m.defs = elfglobals(l.a, mb, hdrsize);
+			m.defs = elfglobals(mb, hdrsize);
 			if (head == nil) { head = m; }
 			else { tail.mnext = m; };
 			tail = m;
@@ -3360,7 +3264,7 @@ fn loadimage(l: *lnk, path: *u8, buf: *u8, len: u64) i32 = {
 
 	// Track this object.
 	let ob: *lobj = alloc(lobj {
-		path     = cstrtostr(l.a, path),
+		path     = cstrtostr(path),
 		buf      = buf,
 		len      = len,
 		textoff  = l.textlen,
@@ -3391,7 +3295,7 @@ fn loadimage(l: *lnk, path: *u8, buf: *u8, len: u64) i32 = {
 		let stvalue: u64 = rdu64(buf, symp + SYM_VALUE);
 		let nmp: *u8 = strtab + (stname: u64);
 		if (nmp[0u64] != 0u8) {
-			let nm: str = cstrtostr(l.a, nmp);
+			let nm: str = cstrtostr(nmp);
 			let gs: *lsym = intern(l, nm);
 			if (stshndx != 0u16) {
 				let intext: bool = (stshndx: i32) == idxtext;
@@ -3455,7 +3359,7 @@ fn loadimage(l: *lnk, path: *u8, buf: *u8, len: u64) i32 = {
 				let sname: u32 = rdu32(buf, sp + SYM_NAME);
 				let snm: *u8 = strtab + (sname: u64);
 				if (snm[0u64] != 0u8) {
-					let nm: str = cstrtostr(l.a, snm);
+					let nm: str = cstrtostr(snm);
 					nr.sym = intern(l, nm);
 				};
 			};
@@ -3491,7 +3395,7 @@ fn loadimage(l: *lnk, path: *u8, buf: *u8, len: u64) i32 = {
 				let sname: u32 = rdu32(buf, sp + SYM_NAME);
 				let snm: *u8 = strtab + (sname: u64);
 				if (snm[0u64] != 0u8) {
-					let nm: str = cstrtostr(l.a, snm);
+					let nm: str = cstrtostr(snm);
 					nr.sym = intern(l, nm);
 				};
 			};
@@ -3517,7 +3421,6 @@ package w6l;
 
 import os;
 import rt;
-import mem;
 import strings;
 import sym;
 
@@ -3612,7 +3515,7 @@ fn dcstrlen(p: *u8) u64 = {
 	return n;
 };
 
-fn dcstrtostr(a: *arena, p: *u8) str = {
+fn dcstrtostr(p: *u8) str = {
 	let n: u64 = dcstrlen(p);
 	let view: str;
 	view.ptr = p;
@@ -3800,7 +3703,7 @@ export fn loadso(l: *lnk, path: *u8) i32 = {
 
 	// Build the lso. Exports are appended in dynsym order so
 	// soprovides_v's first-match semantics match the C version.
-	let so: *lso = alloc(lso { path = dcstrtostr(l.a, path), soname = dcstrtostr(l.a, sonamecs) })!;
+	let so: *lso = alloc(lso { path = dcstrtostr(path), soname = dcstrtostr(sonamecs) })!;
 	let tail: *lexport = nil;
 
 	let si: u64 = 1u64;
@@ -3852,9 +3755,9 @@ export fn loadso(l: *lnk, path: *u8) i32 = {
 			};
 
 			if (keep != 0) {
-				let e: *lexport = alloc(lexport { name = dcstrtostr(l.a, nmp) })!;
+				let e: *lexport = alloc(lexport { name = dcstrtostr(nmp) })!;
 				if (vernamecs != nil) {
-					e.version = dcstrtostr(l.a, vernamecs);
+					e.version = dcstrtostr(vernamecs);
 				};
 				if (tail == nil) {
 					so.exports = e;
@@ -3934,7 +3837,7 @@ def R_X86_64_PC32:  i32 = 2;
 def R_X86_64_PLT32: i32 = 4;
 
 export fn resolve(l: *lnk) i32 = {
-	// Initialise dynamic-linking sentinels. amalloc zeroes, so
+	// Initialise dynamic-linking sentinels. alloc(T{})! zeroes, so
 	// isdyn/dynlib start clean — but pltidx and dynsymidx
 	// must be -1, not 0.
 	let si: *lsym = l.syms;
@@ -4074,7 +3977,6 @@ package w6l;
 
 import os;
 import rt;
-import mem;
 import sym;
 
 // ELF constants
@@ -4218,7 +4120,6 @@ export fn emitdynelf(l: *lnk, fd: i32, base: u64, entry: u64) i32 = {
 	// Placed after .dynamic so the segment is one contiguous run;
 	// relocate runs from here so the dyn layout's datava lands in
 	// patched offsets.
-	let a: *arena = l.a;
 	let n: i32 = l.dynn;
 	let nu: u64 = n: u64;
 
@@ -4996,7 +4897,6 @@ package main;
 
 import os;
 import rt;
-import mem;
 import sym;
 import obj;
 import dyn;
@@ -5006,8 +4906,8 @@ import out;
 def BASE: u64 = 4194304u64;	// 0x400000
 def CODE_VA_OFF: u64 = 4096u64;	// .text starts at base + 0x1000
 
-fn mklnk(a: *arena) *lnk = {
+fn mklnk() *lnk = {
-	let l: *lnk = alloc(lnk { a = a })!;
+	let l: *lnk = alloc(lnk { })!;
 	return l;
 };
 
@@ -5114,9 +5014,9 @@ fn islinkable(path: *u8) bool = {
 };
 
 // Walk libdirs[0..n) trying lib<name>.so, then lib<name>.so.{0..8},
-// then lib<name>.a. Return arena-owned NUL-terminated path on success,
+// then lib<name>.a. Return a heap-allocated NUL-terminated path on
-// nil on miss.
+// success, nil on miss.
-fn resolvelib(a: *arena, name: *u8, libdirs: **u8, nlibdirs: i32) *u8 = {
+fn resolvelib(name: *u8, libdirs: **u8, nlibdirs: i32) *u8 = {
 	let bufp: []u8 = alloc([], 1024u64)!;
 	bufp.len = 1024;
 	let i: i32 = 0;
@@ -5254,8 +5154,7 @@ export fn main(argc: i32, argv: **u8) i32 = {
 		return 2;
 	};
 
-	let a: *arena = newarena();
+	let l: *lnk = mklnk();
-	let l: *lnk = mklnk(a);
 
 	// Seed _start so libwwrt-style start.o is recognised as wanted.
 	intern(l, "_start");
@@ -5273,7 +5172,7 @@ export fn main(argc: i32, argv: **u8) i32 = {
 	// objects register their exports.
 	let lf: i32 = 0;
 	for (lf < nlflags) {
-		let p: *u8 = resolvelib(a, lflags[lf], libdirs.ptr, nlibdirs);
+		let p: *u8 = resolvelib(lflags[lf], libdirs.ptr, nlibdirs);
 		if (p == nil) {
 			os.write(2, "w6l: cannot find -l".ptr, 18u64);
 			let nm: *u8 = lflags[lf];

selfhost/cmd/w6l/main.ww

@@ -10,7 +10,6 @@ package main;
 
 import os;
 import rt;
-import mem;
 import sym;
 import obj;
 import dyn;
@@ -20,8 +19,8 @@ import out;
 def BASE: u64 = 4194304u64;	// 0x400000
 def CODE_VA_OFF: u64 = 4096u64;	// .text starts at base + 0x1000
 
-fn mklnk(a: *arena) *lnk = {
+fn mklnk() *lnk = {
-	let l: *lnk = alloc(lnk { a = a })!;
+	let l: *lnk = alloc(lnk { })!;
 	return l;
 };
 
@@ -128,9 +127,9 @@ fn islinkable(path: *u8) bool = {
 };
 
 // Walk libdirs[0..n) trying lib<name>.so, then lib<name>.so.{0..8},
-// then lib<name>.a. Return arena-owned NUL-terminated path on success,
+// then lib<name>.a. Return a heap-allocated NUL-terminated path on
-// nil on miss.
+// success, nil on miss.
-fn resolvelib(a: *arena, name: *u8, libdirs: **u8, nlibdirs: i32) *u8 = {
+fn resolvelib(name: *u8, libdirs: **u8, nlibdirs: i32) *u8 = {
 	let bufp: []u8 = alloc([], 1024u64)!;
 	bufp.len = 1024;
 	let i: i32 = 0;
@@ -268,8 +267,7 @@ export fn main(argc: i32, argv: **u8) i32 = {
 		return 2;
 	};
 
-	let a: *arena = newarena();
+	let l: *lnk = mklnk();
-	let l: *lnk = mklnk(a);
 
 	// Seed _start so libwwrt-style start.o is recognised as wanted.
 	intern(l, "_start");
@@ -287,7 +285,7 @@ export fn main(argc: i32, argv: **u8) i32 = {
 	// objects register their exports.
 	let lf: i32 = 0;
 	for (lf < nlflags) {
-		let p: *u8 = resolvelib(a, lflags[lf], libdirs.ptr, nlibdirs);
+		let p: *u8 = resolvelib(lflags[lf], libdirs.ptr, nlibdirs);
 		if (p == nil) {
 			os.write(2, "w6l: cannot find -l".ptr, 18u64);
 			let nm: *u8 = lflags[lf];

selfhost/cmd/w6l/obj.ww

@@ -12,7 +12,6 @@ package w6l;
 
 import os;
 import rt;
-import mem;
 import strings;
 import sym;
 
@@ -158,7 +157,7 @@ fn cstrlen(p: *u8) u64 = {
 	return n;
 };
 
-// pathstr — view a NUL-terminated *u8 as a str. Bridges argv/arena
+// pathstr — view a NUL-terminated *u8 as a str. Bridges argv-style
 // callers to lib/os entrypoints (str post-task-#23). Shared with
 // main.ww and dyn.ww via the w6l bundle.
 fn pathstr(p: *u8) str = {
@@ -181,7 +180,7 @@ fn cstreq(p: *u8, lit: str) bool = {
 };
 
 // Build a ww str from a NUL-terminated *u8 (for passing to intern).
-fn cstrtostr(a: *arena, p: *u8) str = {
+fn cstrtostr(p: *u8) str = {
 	let n: u64 = cstrlen(p);
 	let view: str;
 	view.ptr = p;
@@ -201,7 +200,7 @@ type defent = struct {
 };
 
 type armember = struct {
-	data:   *u8,		// arena copy of the member's ELF bytes
+	data:   *u8,		// owned heap copy of the member's ELF bytes
 	size:   u64,
 	defs:   *defent,	// linked list of defined globals
 	loaded: i32,
@@ -236,9 +235,9 @@ fn arfield(p: *u8, n: u64) u64 = {
 };
 
 // elfglobals — return a linked list of names of globally-defined
-// (STB_GLOBAL) symbols whose section is `.text`. Names are arena
+// (STB_GLOBAL) symbols whose section is `.text`. Names are owned
-// copies, so the source ELF buffer can be freed afterward.
+// heap copies, so the source ELF buffer can be freed afterward.
-fn elfglobals(a: *arena, buf: *u8, len: u64) *defent = {
+fn elfglobals(buf: *u8, len: u64) *defent = {
 	if (len < EHDR_SIZE) { return nil; };
 	if (buf[0u64] != 127u8) { return nil; };
 	if (buf[1u64] != 69u8)  { return nil; };
@@ -302,7 +301,7 @@ fn elfglobals(a: *arena, buf: *u8, len: u64) *defent = {
 				if (intext || indt) {
 					let nmp: *u8 = strtab + (stname: u64);
 					if (nmp[0u64] != 0u8) {
-						let nm: str = cstrtostr(a, nmp);
+						let nm: str = cstrtostr(nmp);
 						let de: *defent = alloc(defent { name = nm, dnext = head })!;
 						head = de;
 					};
@@ -355,7 +354,7 @@ fn loadarchive(l: *lnk, path: *u8, buf: *u8, len: u64) i32 = {
 				i += 1u64;
 			};
 			m.data = mb;
-			m.defs = elfglobals(l.a, mb, hdrsize);
+			m.defs = elfglobals(mb, hdrsize);
 			if (head == nil) { head = m; }
 			else { tail.mnext = m; };
 			tail = m;
@@ -473,7 +472,7 @@ fn loadimage(l: *lnk, path: *u8, buf: *u8, len: u64) i32 = {
 
 	// Track this object.
 	let ob: *lobj = alloc(lobj {
-		path     = cstrtostr(l.a, path),
+		path     = cstrtostr(path),
 		buf      = buf,
 		len      = len,
 		textoff  = l.textlen,
@@ -504,7 +503,7 @@ fn loadimage(l: *lnk, path: *u8, buf: *u8, len: u64) i32 = {
 		let stvalue: u64 = rdu64(buf, symp + SYM_VALUE);
 		let nmp: *u8 = strtab + (stname: u64);
 		if (nmp[0u64] != 0u8) {
-			let nm: str = cstrtostr(l.a, nmp);
+			let nm: str = cstrtostr(nmp);
 			let gs: *lsym = intern(l, nm);
 			if (stshndx != 0u16) {
 				let intext: bool = (stshndx: i32) == idxtext;
@@ -568,7 +567,7 @@ fn loadimage(l: *lnk, path: *u8, buf: *u8, len: u64) i32 = {
 				let sname: u32 = rdu32(buf, sp + SYM_NAME);
 				let snm: *u8 = strtab + (sname: u64);
 				if (snm[0u64] != 0u8) {
-					let nm: str = cstrtostr(l.a, snm);
+					let nm: str = cstrtostr(snm);
 					nr.sym = intern(l, nm);
 				};
 			};
@@ -604,7 +603,7 @@ fn loadimage(l: *lnk, path: *u8, buf: *u8, len: u64) i32 = {
 				let sname: u32 = rdu32(buf, sp + SYM_NAME);
 				let snm: *u8 = strtab + (sname: u64);
 				if (snm[0u64] != 0u8) {
-					let nm: str = cstrtostr(l.a, snm);
+					let nm: str = cstrtostr(snm);
 					nr.sym = intern(l, nm);
 				};
 			};

selfhost/cmd/w6l/pass.ww

@@ -21,7 +21,7 @@ def R_X86_64_PC32:  i32 = 2;
 def R_X86_64_PLT32: i32 = 4;
 
 export fn resolve(l: *lnk) i32 = {
-	// Initialise dynamic-linking sentinels. amalloc zeroes, so
+	// Initialise dynamic-linking sentinels. alloc(T{})! zeroes, so
 	// isdyn/dynlib start clean — but pltidx and dynsymidx
 	// must be -1, not 0.
 	let si: *lsym = l.syms;

selfhost/cmd/w6l/sym.ww

@@ -5,8 +5,6 @@
 
 package w6l;
 
-import mem;
-
 type lsym = struct {
 	name:        str,
 	val:         u64,	// offset within combined .text (or .data when
@@ -63,7 +61,6 @@ type lso = struct {
 };
 
 type lnk = struct {
-	a:       *arena,
 	objs:    *lobj,
 	sos:     *lso,
 	syms:    *lsym,