Hojun-Cho
f2643a846a
Receive side of #4's cgreturn ABI (aee8149) for TY_STRUCT lvalues of size <=24B. Producer materialises rhs into AX=bytes[0..7], DX=[8..15], CX=[16..23], zero-padded to 24B; receive sites here read the regs and write only `declared sz` bytes — MOVQ for full 8B chunks plus a sized tail (MOVL/MOVW/MOVB) by the *declared* struct size. ASYMMETRY: do NOT mirror the sender's three uniform MOVQs, else trailing 1..7B chunks overrun the next local slot. Tail chunks in {3,5,6,7} are unreachable under WW struct align rules (size%align==0) and fall through. Five sites wired in each stage (cstage cgen.c, wwstage cgenexpr.ww + cgenstmt.ww), call-result + structlit rhs at each: - N_LET `let s: T = bar()` / `= T{...}` cgenstmt cglet - N_ASSIGN N_IDENT-lhs `s = bar()` / `= T{...}` cgenexpr cgassign - N_ASSIGN single-DOT local-base `o.f = ...` - N_ASSIGN single-DOT ptr-base auto-deref `p.f = ...` - N_ASSIGN single-DOT global-base `g.f = ...` - N_ASSIGN chained-DOT depth>=2 `o.m.in = ...` (The four dot-flavors share one shape pattern, hence "5 sites".) Where the dst addr needs scratch (ptr-base/global-base/via_cx), it is loaded into BX after the call so CX stays as the third value word; for structlit field-walks BX is reloaded before each store since cgexpr clobbers AX/BX between fields. wwstage needed a new `structnaturalsize(si)` helper (cgenutil.ww): si.totsize is mis-named — it's slot-padded to 8 by registerstruct for stack-slot use, while the receive ABI wants the type's natural size (max(foff+fsz)). Splitting si.totsize into naturalsize + slotsize is tracked as the wwstage struct sizing follow-up (task #15); until that lands, the helper recovers the natural size at receive sites. Test 701_cgassign_struct.c (18 rows, 3 checks each — cstage value, wwstage value, asm byte-identity), wired in Makefile after 698. The headline ASYMMETRY case is the 20B `{i32×5}` row: sender pads to 24B via three MOVQs, receiver writes MOVQ AX +0, MOVQ DX +8, MOVL CX +16. A regression to a MOVQ tail there overruns 4B past the slot and flips the exit-code check. smoke.combined.ww is the auto-regen ride-along of strings.freeall landing in714d089(worker-shlex). Pre-existing gaps surfaced and tracked separately (not fixed here, out of scope): - task #16: silent drop of `(*p).f = ...` explicit-deref dot lhs. - task #17: silent zero of nested STRUCTLIT field in N_LET / N_ASSIGN initializer — the field_chain and field_global test rows use explicit field writes (`o.m.t = 10i64;`) rather than nested literals as a fixture-level workaround. - task #9: module-name-mangle for fn labels avoided in the field_global_call fixture by `let g: outer;` (no init). make test: 59/59. 994_w6c_ww + 995_self_rebuild PASS — bootstrap byte-identity is the load-bearing proof for this commit's scope.
2786 lines
90 KiB
Plaintext
2786 lines
90 KiB
Plaintext
// selfhost/cmd/wcc/cgenutil.ww — split out of cgen.ww.
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//
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// General helpers used across cgenexpr / cgenstmt / cgendecl:
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// - pushargsrev: per-call arg pushing
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// - type predicates: isstr*/isslice*/istagged*/nodeis* families
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// - field ops: fieldloadop, fieldstoreop
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// - index helpers: indexbaseesz, dotinnerstructptr, elemsizeof
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// - slot sizing: structlookup, primsize, slotsize, fieldsize,
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// registerstruct, collectstructs
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// - rhs helpers: rhstargetname, taggedvariantindex
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//
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// Bundler pulls this in transitively via cgen.ww; consumers don't
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// need to `use cgenutil;` directly.
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use os;
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use mem;
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use ast;
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use tok;
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use typ;
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use sym;
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use strconv;
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// ---- variadic-call helpers (Hare-style `T...` param) -----------------
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// slicewrap — synthesise an N_TSLICE node wrapping the given element
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// type AST. Used by the Hare-style variadic path so the local entry
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// for the param (callee side) and the call-site slice descriptor
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// (caller side) both advertise their effective type as []ELEM —
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// every isslicetype / nodeisslice check then succeeds naturally.
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fn slicewrap(c: *cgen, elem: *node) *node = {
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let s: *node = newnode(c.a, nkind.N_TSLICE, "", 0, 0);
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s.lhs = elem;
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return s;
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};
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// findvariadicparam — walk a param-list head and return the variadic
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// param node (the one with op == TK_ELLIPSIS) plus the count of
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// non-variadic params before it. Returns nil/0 when no variadic.
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// nfixed_out cannot be nil.
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fn findvariadicparam(ps: *node, nfixed_out: *i32) *node = {
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*nfixed_out = 0;
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let p: *node = ps;
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for (p != nil) {
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if (p.kind == nkind.N_PARAM) {
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if (p.op == tkind.TK_ELLIPSIS) {
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return p;
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};
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*nfixed_out += 1;
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};
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p = p.next;
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};
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return nil;
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};
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// callee_variadic_param — convenience wrapper: looks up the callee
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// by name and finds its variadic param + nfixed. Returns nil if the
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// callee isn't registered or has no variadic param.
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fn callee_variadic_param(c: *cgen, callee: *node, nfixed_out: *i32) *node = {
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*nfixed_out = 0;
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if (callee == nil) { return nil; };
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let cnm: str;
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cnm.ptr = nil; cnm.len = 0;
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if (callee.kind == nkind.N_IDENT) { cnm = callee.str; };
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if (callee.kind == nkind.N_DOT) { cnm = callee.str; };
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if (cnm.len == 0) { return nil; };
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let ps: *node = fnparamslookup(c, cnm);
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return findvariadicparam(ps, nfixed_out);
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};
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// mkvarargname — fresh local-slot name "<prefix><seq>". Used for
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// the per-variadic-call scratch buffers (`@vararg_d_N` for the
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// element-data buffer, `@vararg_sl_N` for the 24B slice descriptor)
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// where N is recorded on the N_CALL node at scanlocals time so both
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// the prologue reservation and the call-site emission agree.
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fn mkvarargname(c: *cgen, prefix: str, seq: i32) str = {
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let buf: [128]u8;
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let i: i32 = 0;
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let j: i32 = 0;
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for (j < prefix.len) {
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buf[i] = prefix[j];
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i += 1; j += 1;
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};
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let ns: str = strconv.i64tos(seq: i64, strconv.base.DEC);
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let n: i32 = ns.len;
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let dk: i32 = 0;
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for (dk < n) { buf[i + dk] = ns.ptr[dk]; dk += 1; };
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let total: i32 = i + n;
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let p: *u8 = amalloc(c.a, (total: u64) + 1u64): *u8;
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let k: i32 = 0;
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for (k < total) { p[k] = buf[k]; k += 1; };
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p[total] = 0u8;
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let r: str;
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r.ptr = p;
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r.len = total;
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return r;
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};
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// ---- expression cgen -------------------------------------------------
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// pushargsrev — recursively walks the arg list, evaluates rightmost
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// first, and pushes. str args take two slots (ptr in AX, len in BX);
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// the order on the stack so a left-to-right pop into argregs lands
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// (ptr, len) correctly is: PUSHQ BX (top), PUSHQ AX (above) — the
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// pop sequence then yields AX, then BX.
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//
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// `param` is the corresponding declared parameter for `arg` (N_PARAM
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// node from the callee's signature) or nil. When param's type is a
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// tagged union and `arg`'s surface type is a concrete variant of it,
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// we materialise (tag, value-words, pad) for the parameter slot before
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// pushing — mirrors cmd/w6c/cgen.c's call-arg widening.
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fn pushargsrev(c: *cgen, arg: *node, param: *node) i32 = {
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if (arg == nil) { return 0; };
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let nextparam: *node = nil;
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if (param != nil) { nextparam = param.next; };
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let rest: i32 = pushargsrev(c, arg.next, nextparam);
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// Implicit widening from a concrete variant to a tagged-union
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// parameter slot. Skips when the arg is already a tagged local
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// (line 121's slice-or-tagged shortcut handles that).
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let widensz: i32 = 0;
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let widentag: i32 = 0;
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if (param != nil) {
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if (param.kind == nkind.N_PARAM) {
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// Hare-style variadic `T...`: effective param type is
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// []T (slice). The arg here is the synthesised slice
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// descriptor (or a forwarded `xs...` slice), not a
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// value of T being widened into a tagged slot — skip
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// the widening detection so the slice-ident fast path
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// at the bottom of pushargsrev gets the push.
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if (param.op == tkind.TK_ELLIPSIS) {
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widensz = 0;
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} else {
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let ptype: *node = param.lhs;
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if (istaggedtype(c, ptype)) {
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let aistagged: bool = false;
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if (arg.kind == nkind.N_IDENT) {
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let lc: *local = localfindnode(c, arg.str);
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if (lc != nil) {
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aistagged = istaggedtype(c, lc.tnode);
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};
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};
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if (!aistagged) {
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widensz = slotsize(c, ptype);
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let tagged: *node = resolvetagged(c, ptype);
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let t: i32 = taggedvariantindex(c, tagged, arg);
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if (t < 0) { t = 0; };
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widentag = t;
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};
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};
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};
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};
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};
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if (widensz == 8) {
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// Nullable fold: pointer value IS the discriminator. No
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// separate tag word.
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cgexpr(c, arg);
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emitline("\tPUSHQ\tAX\n");
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return rest + 1;
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};
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if (widensz > 0) {
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// Struct-payload widening into a tagged-union param uses
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// @tagscr (zero + cgwidentaggedstore writes fields + tag,
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// then push slot words high → low). Scalar / str go via
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// the direct push fast path below — keeps wwstage's asm
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// byte-identical to cstage for selfhost source.
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let pname: str = rhsstructpayload(c, arg);
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if (pname.len > 0) {
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let ptype: *node = param.lhs;
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let scroff: i32 = localadd(c, "@tagscr", 24, nil);
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emitline("\tXORQ\tAX, AX\n");
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let zz: i32 = 0;
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for (zz < widensz) {
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emitline("\tMOVQ\tAX, ");
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emitoff((scroff + zz): i64);
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emitline("(BP)\n");
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zz += 8;
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};
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cgwidentaggedstore(c, ptype, arg, "BP", scroff, widensz);
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let pp: i32 = widensz - 8;
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for (pp >= 0) {
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emitline("\tMOVQ\t");
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emitoff((scroff + pp): i64);
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emitline("(BP), AX\n");
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emitline("\tPUSHQ\tAX\n");
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pp -= 8;
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};
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return rest + widensz / 8;
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};
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cgexpr(c, arg);
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if (nodeisslice(c, arg)) {
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// Slice payload (24B): cgexpr leaves (AX=ptr, BX=len,
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// CX=cap). Slot layout: [+0]=tag, [+8]=ptr, [+16]=len,
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// [+24]=cap. Push high→low so pop drains tag first.
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// Requires widensz >= 32; a smaller slot would mean the
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// destination union doesn't list slice as a variant
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// (caller should have flagged a type error).
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emitline("\tPUSHQ\tCX\n");
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emitline("\tPUSHQ\tBX\n");
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emitline("\tPUSHQ\tAX\n");
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emitline("\tMOVQ\t$");
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emitint(widentag: i64);
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emitline(", AX\n");
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emitline("\tPUSHQ\tAX\n");
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} else { if (nodeisstr(c, arg)) {
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// slot 24: [+0]=tag,[+8]=ptr,[+16]=len. Push high→low
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// so pop drains tag first into arg-reg[0].
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emitline("\tPUSHQ\tBX\n");
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emitline("\tPUSHQ\tAX\n");
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emitline("\tMOVQ\t$");
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emitint(widentag: i64);
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emitline(", AX\n");
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emitline("\tPUSHQ\tAX\n");
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} else {
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// Scalar variant: single value word at +8. Pad a zero
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// high word when slot is 24B (some other variant of
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// the union is 16B-shaped).
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let pp: i32 = widensz - 8;
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for (pp > 8) {
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emitline("\tXORQ\tDX, DX\n");
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emitline("\tPUSHQ\tDX\n");
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pp -= 8;
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};
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emitline("\tPUSHQ\tAX\n");
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emitline("\tMOVQ\t$");
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emitint(widentag: i64);
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emitline(", AX\n");
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emitline("\tPUSHQ\tAX\n");
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};};
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return rest + widensz / 8;
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};
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// nkind.N_SLICE expression as arg: `buf[lo:hi]` builds a slice header
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// on the stack matching C cgen's sequence — push base, push hi,
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// compute lo, pop into BX/CX, derive len/ptr, push (cap, len, ptr).
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if (arg.kind == nkind.N_SLICE) {
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let base: *node = arg.lhs;
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let lo: *node = arg.rhs;
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let hi: *node = arg.cond;
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let baselocal: *local = nil;
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let globaltn: *node = nil;
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let globalname: str;
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globalname.ptr = nil; globalname.len = 0;
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if (base != nil) {
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if (base.kind == nkind.N_IDENT) {
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let bn: str = base.str;
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baselocal = localfindnode(c, bn);
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if (baselocal == nil) {
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let gt: *node = letvartnode(c, bn);
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if (gt != nil) {
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globaltn = gt;
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globalname = bn;
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};
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};
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};
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};
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// base address → push
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if (baselocal != nil) {
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let tn: *node = baselocal.tnode;
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if (tn != nil) {
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if (tn.kind == nkind.N_TARRAY) {
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emitline("\tLEAQ\t");
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emitoff(baselocal.off: i64);
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emitline("(BP), AX\n");
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} else {
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emitline("\tMOVQ\t");
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emitoff(baselocal.off: i64);
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emitline("(BP), AX\n");
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};
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} else {
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emitline("\tMOVQ\t");
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emitoff(baselocal.off: i64);
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emitline("(BP), AX\n");
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};
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} else { if (globaltn != nil) {
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if (globaltn.kind == nkind.N_TARRAY) {
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emitline("\tLEAQ\t");
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emitsymname(c, globalname);
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emitline("(SB), AX\n");
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} else {
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emitline("\tMOVQ\t");
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emitsymname(c, globalname);
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emitline("(SB), AX\n");
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};
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} else {
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cgexpr(c, base);
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};};
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emitline("\tPUSHQ\tAX\n");
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// hi (default base length) → push
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if (hi != nil) {
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cgexpr(c, hi);
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} else { if (baselocal != nil) {
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let tn: *node = baselocal.tnode;
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if (tn != nil) {
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if (tn.kind == nkind.N_TARRAY) {
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let lenn: *node = tn.rhs;
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if (lenn != nil) {
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if (lenn.kind == nkind.N_INTLIT) {
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emitline("\tMOVQ\t$");
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emituint(lenn.uval);
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emitline(", AX\n");
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};
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};
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} else { if (tn.kind == nkind.N_TSLICE) {
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emitline("\tMOVQ\t");
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emitoff((baselocal.off + 8): i64);
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emitline("(BP), AX\n");
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} else { if (tn.kind == nkind.N_TNAME) {
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if (streq(tn.str, "str")) {
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emitline("\tMOVQ\t");
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emitoff((baselocal.off + 8): i64);
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emitline("(BP), AX\n");
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};
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};};};
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};
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} else { if (globaltn != nil) {
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if (globaltn.kind == nkind.N_TARRAY) {
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let lenn: *node = globaltn.rhs;
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if (lenn != nil) {
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if (lenn.kind == nkind.N_INTLIT) {
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emitline("\tMOVQ\t$");
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emituint(lenn.uval);
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emitline(", AX\n");
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};
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};
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} else { if (globaltn.kind == nkind.N_TSLICE) {
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emitline("\tLEAQ\t");
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emitsymname(c, globalname);
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emitline("(SB), CX\n");
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emitline("\tMOVQ\t8(CX), AX\n");
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};};
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} else {
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emitline("\tMOVQ\t$0, AX\n");
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};};};
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emitline("\tPUSHQ\tAX\n");
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// lo (default 0) → AX
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if (lo != nil) { cgexpr(c, lo); }
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else { emitline("\tMOVQ\t$0, AX\n"); };
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emitline("\tPOPQ\tBX\n"); // hi
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emitline("\tPOPQ\tCX\n"); // base
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emitline("\tMOVQ\tBX, DX\n"); // DX = hi
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emitline("\tSUBQ\tAX, DX\n"); // DX = hi - lo = len
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emitline("\tADDQ\tAX, CX\n"); // CX = base + lo = ptr
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emitline("\tPUSHQ\tDX\n"); // cap
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emitline("\tPUSHQ\tDX\n"); // len
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emitline("\tPUSHQ\tCX\n"); // ptr (top)
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return rest + 3;
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};
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// Slice/tagged ident args: emit per-register MOVQ+PUSHQ pairs in
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// reverse order (cap/v1, len/v0, ptr/tag) so a left-to-right pop
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// into argregs lands the canonical (ptr/tag, len/v0, cap/v1).
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// For tagged ident with a >24B slot (slice-payload variant),
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// push a fourth word from off+24.
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if (arg.kind == nkind.N_IDENT) {
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let nm: str = arg.str;
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let lc: *local = localfindnode(c, nm);
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if (lc != nil) {
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let off: i32 = lc.off;
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if (isslicetype(c, lc.tnode) || istaggedtype(c, lc.tnode)) {
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let nwords: i32 = 3;
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if (istaggedtype(c, lc.tnode)) {
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let ssz: i32 = slotsize(c, lc.tnode);
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nwords = ssz / 8;
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};
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let w: i32 = nwords - 1;
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for (w >= 0) {
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emitline("\tMOVQ\t");
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emitoff((off + w*8): i64);
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emitline("(BP), AX\n");
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emitline("\tPUSHQ\tAX\n");
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w -= 1;
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};
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return rest + nwords;
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};
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};
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};
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// Float arg: cgexpr leaves the value in X0. Push 8 bytes from
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// X0 via SUBQ+MOVSD so cgcall's pop side can drain into the
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// XMM stream (X0..X7). f32 still occupies 8B on the stack —
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// the MOVSS load on the pop side touches only the low 4.
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let fk: i32 = exprfloatkind(c, arg);
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if (fk != 0) {
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cgexpr(c, arg);
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let mov: str = "MOVSD";
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if (fk == 1) { mov = "MOVSS"; };
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emitline("\tSUBQ\t$8, SP\n");
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emitline("\t");
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emitline(mov);
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emitline("\tX0, (SP)\n");
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return rest + 1;
|
||
};
|
||
cgexpr(c, arg);
|
||
if (nodeisslice(c, arg)) {
|
||
emitline("\tPUSHQ\tCX\n");
|
||
emitline("\tPUSHQ\tBX\n");
|
||
emitline("\tPUSHQ\tAX\n");
|
||
return rest + 3;
|
||
};
|
||
if (nodeisstr(c, arg)) {
|
||
emitline("\tPUSHQ\tBX\n");
|
||
emitline("\tPUSHQ\tAX\n");
|
||
return rest + 2;
|
||
};
|
||
emitline("\tPUSHQ\tAX\n");
|
||
return rest + 1;
|
||
};
|
||
|
||
fn nodeisslice(c: *cgen, n: *node) bool = {
|
||
if (n == nil) { return false; };
|
||
let k: nkind = n.kind;
|
||
if (k == nkind.N_IDENT) {
|
||
let nm: str = n.str;
|
||
let lc: *local = localfindnode(c, nm);
|
||
if (lc != nil) { return isslicetype(c, lc.tnode); };
|
||
return false;
|
||
};
|
||
if (k == nkind.N_SLICE) { return true; };
|
||
if (k == nkind.N_CAST) { return isslicetype(c, n.rhs); };
|
||
// N_DOT to a slice field: resolve the field through the struct
|
||
// (or *struct) the base ident / inner chain lands on, then check
|
||
// the field tnode. Mirrors nodeisstr's N_DOT branch so call-arg
|
||
// push/pop counts 3 words for `p.sl` and `p.inner.sl` shapes.
|
||
// `.ptr` / `.len` / `.cap` are pseudo-fields — they yield ptr
|
||
// (*u8) and i32, not a slice — so we exclude them up front.
|
||
if (k == nkind.N_DOT) {
|
||
let base: *node = n.lhs;
|
||
let fld: str = n.str;
|
||
if (streq(fld, "ptr")) { return false; };
|
||
if (streq(fld, "len")) { return false; };
|
||
if (streq(fld, "cap")) { return false; };
|
||
if (base != nil) {
|
||
let sname: str;
|
||
sname.ptr = nil; sname.len = 0;
|
||
if (base.kind == nkind.N_IDENT) {
|
||
let lc: *local = localfindnode(c, base.str);
|
||
if (lc != nil) {
|
||
let tn: *node = lc.tnode;
|
||
let lkind: nkind = nkind.N_NONE;
|
||
if (tn != nil) { lkind = tn.kind; };
|
||
if (lkind == nkind.N_TNAME) { sname = tn.str; };
|
||
if (lkind == nkind.N_TPTR) {
|
||
let inner: *node = tn.lhs;
|
||
if (inner != nil) {
|
||
if (inner.kind == nkind.N_TNAME) { sname = inner.str; };
|
||
};
|
||
};
|
||
};
|
||
};
|
||
if (base.kind == nkind.N_DOT) {
|
||
let innert: *node = dotinnerstructptr(c, base);
|
||
if (innert != nil) {
|
||
if (innert.kind == nkind.N_TNAME) { sname = innert.str; };
|
||
};
|
||
};
|
||
if (sname.len > 0) {
|
||
let si: *structinfo = structlookup(c, sname);
|
||
if (si != nil) {
|
||
let fi: *fieldinfo = si.fields;
|
||
for (fi != nil) {
|
||
if (streq(fi.fname, fld)) {
|
||
return isslicetype(c, fi.tnode);
|
||
};
|
||
fi = fi.finext;
|
||
};
|
||
};
|
||
};
|
||
// Chained dot through value-struct hops (`o.inner.sl`,
|
||
// `p.inner.sl`): dotinnerstructptr above only walks
|
||
// *struct fields, so a value-struct chain falls through.
|
||
// dotchainresolve handles arbitrary depth through value
|
||
// struct AND `*T` root, returning the leaf fieldinfo.
|
||
let rootnm: str = "";
|
||
let rootoff: i32 = 0;
|
||
let totaloff: i32 = 0;
|
||
let lfi: *fieldinfo = nil;
|
||
let sdelta: i32 = -1;
|
||
let isglobal: bool = false;
|
||
let ptrroot: bool = false;
|
||
let ok: bool = dotchainresolve(c, n,
|
||
&rootnm, &rootoff, &totaloff,
|
||
&lfi, &sdelta, &isglobal, &ptrroot);
|
||
if (ok && sdelta < 0 && lfi != nil) {
|
||
return isslicetype(c, lfi.tnode);
|
||
};
|
||
};
|
||
return false;
|
||
};
|
||
return false;
|
||
};
|
||
|
||
// nodeisstr — best-effort surface check: does this expression
|
||
// evaluate to a str value? Used to drive the call-arg push convention
|
||
// (str args take two slots: ptr + len).
|
||
fn nodeisstr(c: *cgen, n: *node) bool = {
|
||
if (n == nil) { return false; };
|
||
let k: nkind = n.kind;
|
||
if (k == nkind.N_STRLIT) { return true; };
|
||
if (k == nkind.N_IDENT) {
|
||
let nm: str = n.str;
|
||
let lc: *local = localfindnode(c, nm);
|
||
if (lc != nil) {
|
||
// Use isstrtype so `!str` aliases (parserr = !str) and
|
||
// `type foo = str;` chains resolve through. The bare
|
||
// `streq("str", ...)` test missed them and dropped the
|
||
// MOVQ BX,CX shuffle on returns of str-aliased locals.
|
||
if (isstrtype(c, lc.tnode)) { return true; };
|
||
};
|
||
return false;
|
||
};
|
||
if (k == nkind.N_CALL) {
|
||
let callee: *node = n.lhs;
|
||
if (callee != nil) {
|
||
if (callee.kind == nkind.N_IDENT) {
|
||
let cnm: str = callee.str;
|
||
let rt: *node = fnretlookup(c, cnm);
|
||
return isstrtype(c, rt);
|
||
};
|
||
};
|
||
return false;
|
||
};
|
||
if (k == nkind.N_DOT) {
|
||
let base: *node = n.lhs;
|
||
let fld: str = n.str;
|
||
// `<expr>.ptr` is *u8 not str; `<expr>.len` is i32 not str.
|
||
if (streq(fld, "ptr")) { return false; };
|
||
if (streq(fld, "len")) { return false; };
|
||
if (streq(fld, "cap")) { return false; };
|
||
if (base != nil) {
|
||
let sname: str;
|
||
sname.ptr = nil; sname.len = 0;
|
||
if (base.kind == nkind.N_IDENT) {
|
||
let lc: *local = localfindnode(c, base.str);
|
||
if (lc != nil) {
|
||
let tn: *node = lc.tnode;
|
||
let lkind: nkind = nkind.N_NONE;
|
||
if (tn != nil) { lkind = tn.kind; };
|
||
if (lkind == nkind.N_TNAME) { sname = tn.str; };
|
||
if (lkind == nkind.N_TPTR) {
|
||
let inner: *node = tn.lhs;
|
||
if (inner != nil) {
|
||
if (inner.kind == nkind.N_TNAME) { sname = inner.str; };
|
||
};
|
||
};
|
||
};
|
||
};
|
||
// Chained dot (`p.foo.bar`): use dotinnerstructptr
|
||
// to resolve the inner chain to the *struct it lands
|
||
// on, then look up `fld` in that struct.
|
||
if (base.kind == nkind.N_DOT) {
|
||
let innert: *node = dotinnerstructptr(c, base);
|
||
if (innert != nil) {
|
||
if (innert.kind == nkind.N_TNAME) { sname = innert.str; };
|
||
};
|
||
};
|
||
if (sname.len > 0) {
|
||
let si: *structinfo = structlookup(c, sname);
|
||
if (si != nil) {
|
||
let fi: *fieldinfo = si.fields;
|
||
for (fi != nil) {
|
||
let fn_: str = fi.fname;
|
||
if (streq(fn_, fld)) {
|
||
return isstrtype(c, fi.tnode);
|
||
};
|
||
fi = fi.finext;
|
||
};
|
||
};
|
||
};
|
||
// Chained dot through value-struct hops (`p.inner.s`):
|
||
// dotinnerstructptr above only walks *struct fields;
|
||
// dotchainresolve handles arbitrary depth through
|
||
// value struct AND `*T` root. Mirror of the nodeisslice
|
||
// fallback so chained str-field args also push 2 words.
|
||
let rootnm: str = "";
|
||
let rootoff: i32 = 0;
|
||
let totaloff: i32 = 0;
|
||
let lfi: *fieldinfo = nil;
|
||
let sdelta: i32 = -1;
|
||
let isglobal: bool = false;
|
||
let ptrroot: bool = false;
|
||
let ok: bool = dotchainresolve(c, n,
|
||
&rootnm, &rootoff, &totaloff,
|
||
&lfi, &sdelta, &isglobal, &ptrroot);
|
||
if (ok && sdelta < 0 && lfi != nil) {
|
||
return isstrtype(c, lfi.tnode);
|
||
};
|
||
};
|
||
return false;
|
||
};
|
||
if (k == nkind.N_CAST) {
|
||
return isstrtype(c, n.rhs);
|
||
};
|
||
return false;
|
||
};
|
||
|
||
// typenameisunsigned — true for u8/u16/u32/u64/uint/uintptr/rune.
|
||
// rune is a Unicode codepoint (0..0x10FFFF); cgen treats it as
|
||
// unsigned so narrow-cast / sub-word load paths zero-extend (MOVL,
|
||
// not MOVSXD). Mirrors cstage's type_isunsigned post task #5.
|
||
fn typenameisunsigned(nm: str) bool = {
|
||
if (streq(nm, "u8")) { return true; };
|
||
if (streq(nm, "u16")) { return true; };
|
||
if (streq(nm, "u32")) { return true; };
|
||
if (streq(nm, "u64")) { return true; };
|
||
if (streq(nm, "uint")) { return true; };
|
||
if (streq(nm, "uintptr")) { return true; };
|
||
if (streq(nm, "rune")) { return true; };
|
||
return false;
|
||
};
|
||
|
||
// typenodeisunsigned — recurse through TNAME aliases / TBANG / TENUM
|
||
// to the resolved primitive. Mirrors cstage's type_isunsigned which
|
||
// recurses into TY_NAMED.under and TY_ENUM.sub.
|
||
fn typenodeisunsignedc(c: *cgen, t: *node) bool = {
|
||
if (t == nil) { return false; };
|
||
let k: nkind = t.kind;
|
||
if (k == nkind.N_TBANG) { return typenodeisunsignedc(c, t.lhs); };
|
||
if (k == nkind.N_TENUM) { return typenodeisunsignedc(c, t.lhs); };
|
||
if (k == nkind.N_TNAME) {
|
||
let nm: str = t.str;
|
||
if (typenameisunsigned(nm)) { return true; };
|
||
if (typenameissigned(nm)) { return false; };
|
||
// Follow aliases / enum storage.
|
||
let al: *node = aliaslookup(c, nm);
|
||
if (al != nil) { return typenodeisunsignedc(c, al); };
|
||
let en: *enumtype = enumlookup(c, nm);
|
||
if (en != nil) {
|
||
if (en.storage != nil) {
|
||
return typenodeisunsignedc(c, en.storage);
|
||
};
|
||
return false; // default storage i32 is signed
|
||
};
|
||
};
|
||
return false;
|
||
};
|
||
|
||
// typenodeisunsigned — legacy callers without *cgen context. Only
|
||
// resolves primitive TNAMEs (no alias/enum recursion); use the
|
||
// _c variant where the cgen registry is in scope.
|
||
fn typenodeisunsigned(t: *node) bool = {
|
||
if (t == nil) { return false; };
|
||
if (t.kind == nkind.N_TNAME) { return typenameisunsigned(t.str); };
|
||
return false;
|
||
};
|
||
|
||
// typeis8byteprimitive — does this type take exactly one 8-byte
|
||
// slot (pointer / fn-ptr / 64-bit int / chan / scalar primitive
|
||
// padded up to 8) rather than a wider aggregate? Used by nkind.N_LET
|
||
// zero-init to mirror C cgen's "only zero if sz == 8 at the type
|
||
// level" rule. Strings (16), slices (24), tagged unions (>=16),
|
||
// tuples (16), structs (varies), arrays — all fall through to
|
||
// false here even when their *slot* rounds up to 8.
|
||
fn typeis8byteprimitive(c: *cgen, t: *node) bool = {
|
||
if (t == nil) { return false; };
|
||
let k: nkind = t.kind;
|
||
if (k == nkind.N_TPTR) { return true; };
|
||
if (k == nkind.N_TFN) { return true; };
|
||
if (k == nkind.N_TCHAN) { return true; };
|
||
if (k == nkind.N_TSLICE) { return false; };
|
||
if (k == nkind.N_TARRAY) {
|
||
// C cgen (cmd/w6c/cgen.c:3317) zero-inits TY_ARRAY whenever
|
||
// its raw byte size is 8 — e.g. `[8]bool`, `[2]i32`, `[4]i16`,
|
||
// `[1]i64`. Mirror that here so the wwstage matches.
|
||
let lenn: *node = t.rhs;
|
||
let elemn: *node = t.lhs;
|
||
if (lenn == nil) { return false; };
|
||
if (lenn.kind != nkind.N_INTLIT) { return false; };
|
||
let elen: i64 = lenn.uval: i64;
|
||
let esz: i32 = 8;
|
||
if (elemn != nil) {
|
||
if (elemn.kind == nkind.N_TNAME) {
|
||
let ps: i32 = primsize(elemn.str);
|
||
if (ps > 0) { esz = ps; };
|
||
};
|
||
};
|
||
return (esz: i64 * elen) == 8i64;
|
||
};
|
||
if (k == nkind.N_TTUPLE) { return false; };
|
||
if (k == nkind.N_TTAGGED){ return false; };
|
||
if (k == nkind.N_TNAME) {
|
||
let nm: str = t.str;
|
||
if (streq(nm, "str")) { return false; };
|
||
// Struct alias: not a primitive even if the slot is 8B.
|
||
if (structlookup(c, nm) != nil) { return false; };
|
||
// Primitive (i8/u8/.../i64/u64/bool/rune/f32/f64/int/...).
|
||
// All of these get slot-padded to 8 and zero-init in C.
|
||
if (primsize(nm) > 0) { return true; };
|
||
return false;
|
||
};
|
||
return false;
|
||
};
|
||
|
||
// elemissigned — given an indexable type (`*T`, `[]T`, `[N]T`), is
|
||
// its element a signed narrow primitive (i8/i16/i32)? Used by
|
||
// cgindex to pick MOVSXD vs MOVL at esz=4 (and MOVSBQ/MOVSWQ at
|
||
// esz=1/2). Mirrors cstage's `signed_elem`. Follows alias/enum
|
||
// chains so `[]Alias` arrays resolve to the underlying signedness.
|
||
fn elemissignedc(c: *cgen, t: *node) bool = {
|
||
if (t == nil) { return false; };
|
||
let elem: *node = nil;
|
||
let k: nkind = t.kind;
|
||
if (k == nkind.N_TPTR) { elem = t.lhs; };
|
||
if (k == nkind.N_TSLICE) { elem = t.lhs; };
|
||
if (k == nkind.N_TARRAY) { elem = t.lhs; };
|
||
if (elem == nil) { return false; };
|
||
return fieldissignedc(c, elem);
|
||
};
|
||
|
||
fn elemissigned(t: *node) bool = {
|
||
if (t == nil) { return false; };
|
||
let elem: *node = nil;
|
||
let k: nkind = t.kind;
|
||
if (k == nkind.N_TPTR) { elem = t.lhs; };
|
||
if (k == nkind.N_TSLICE) { elem = t.lhs; };
|
||
if (k == nkind.N_TARRAY) { elem = t.lhs; };
|
||
if (elem == nil) { return false; };
|
||
if (elem.kind != nkind.N_TNAME) { return false; };
|
||
return typenameissigned(elem.str);
|
||
};
|
||
|
||
// typenameissigned — true for i8/i16/i32/i64/int. rune is excluded
|
||
// (it's a non-negative Unicode codepoint, treated as unsigned).
|
||
fn typenameissigned(nm: str) bool = {
|
||
if (streq(nm, "i8")) { return true; };
|
||
if (streq(nm, "i16")) { return true; };
|
||
if (streq(nm, "i32")) { return true; };
|
||
if (streq(nm, "i64")) { return true; };
|
||
if (streq(nm, "int")) { return true; };
|
||
return false;
|
||
};
|
||
|
||
// fieldissignedc — does this field/element type need sign-extension
|
||
// on a sub-word load? Walks TBANG / TENUM / TNAME-aliases to the
|
||
// resolved primitive. Mirrors cstage's fld_issigned: bool is treated
|
||
// as unsigned (0/1 ⇒ MOVZBQ); rune is unsigned (codepoint ⇒ MOVL).
|
||
fn fieldissignedc(c: *cgen, t: *node) bool = {
|
||
if (t == nil) { return false; };
|
||
let k: nkind = t.kind;
|
||
if (k == nkind.N_TBANG) { return fieldissignedc(c, t.lhs); };
|
||
if (k == nkind.N_TENUM) { return fieldissignedc(c, t.lhs); };
|
||
if (k == nkind.N_TNAME) {
|
||
let nm: str = t.str;
|
||
if (streq(nm, "bool")) { return false; };
|
||
if (typenameisunsigned(nm)) { return false; };
|
||
if (typenameissigned(nm)) { return true; };
|
||
let al: *node = aliaslookup(c, nm);
|
||
if (al != nil) { return fieldissignedc(c, al); };
|
||
let en: *enumtype = enumlookup(c, nm);
|
||
if (en != nil) {
|
||
if (en.storage != nil) {
|
||
return fieldissignedc(c, en.storage);
|
||
};
|
||
return true; // default i32 storage is signed
|
||
};
|
||
};
|
||
return false;
|
||
};
|
||
|
||
// fieldloadop — pick the load instruction for a non-str struct
|
||
// field by its declared size + signedness. Mirrors cstage's
|
||
// fldloadop: MOVZBQ/MOVSBQ for 1B, MOVZWQ/MOVSWQ for 2B,
|
||
// MOVL/MOVSXD for 4B, MOVQ for 8B. f might be nil for fields
|
||
// outside our struct registry.
|
||
fn fieldloadop(c: *cgen, f: *fieldinfo) str = {
|
||
if (f == nil) { return "MOVQ"; };
|
||
let sz: i32 = f.fsz;
|
||
let sigd: bool = fieldissignedc(c, f.tnode);
|
||
if (sz == 1) { if (sigd) { return "MOVSBQ"; }; return "MOVZBQ"; };
|
||
if (sz == 2) { if (sigd) { return "MOVSWQ"; }; return "MOVZWQ"; };
|
||
if (sz == 4) { if (sigd) { return "MOVSXD"; }; return "MOVL"; };
|
||
return "MOVQ";
|
||
};
|
||
|
||
// fieldstoreop — pick the store instruction for a non-str struct
|
||
// field by its declared size. MOVB for 1, MOVW for 2, MOVL for 4,
|
||
// MOVQ for 8. c kept in the signature for symmetry with fieldloadop.
|
||
fn fieldstoreop(c: *cgen, f: *fieldinfo) str = {
|
||
if (f == nil) { return "MOVQ"; };
|
||
let sz: i32 = f.fsz;
|
||
if (sz == 1) { return "MOVB"; };
|
||
if (sz == 2) { return "MOVW"; };
|
||
if (sz == 4) { return "MOVL"; };
|
||
return "MOVQ";
|
||
};
|
||
|
||
// tnodeloadop / tnodestoreop — same dispatch as fieldloadop /
|
||
// fieldstoreop but keyed on a raw type-AST node (tuple element type,
|
||
// pointer-target, slice-element, etc.) rather than a struct fieldinfo.
|
||
// Used at the index / tuple / pointer-deref sites where there's no
|
||
// fieldinfo entry but the type-node + size are both known.
|
||
fn tnodeloadop(c: *cgen, t: *node, sz: i32) str = {
|
||
let sigd: bool = fieldissignedc(c, t);
|
||
if (sz == 1) { if (sigd) { return "MOVSBQ"; }; return "MOVZBQ"; };
|
||
if (sz == 2) { if (sigd) { return "MOVSWQ"; }; return "MOVZWQ"; };
|
||
if (sz == 4) { if (sigd) { return "MOVSXD"; }; return "MOVL"; };
|
||
return "MOVQ";
|
||
};
|
||
|
||
fn tnodestoreop(c: *cgen, t: *node, sz: i32) str = {
|
||
if (sz == 1) { return "MOVB"; };
|
||
if (sz == 2) { return "MOVW"; };
|
||
if (sz == 4) { return "MOVL"; };
|
||
return "MOVQ";
|
||
};
|
||
|
||
// loadopsz — load op when the (size, signedness) pair has already
|
||
// been resolved upstream and the type-node isn't carried through.
|
||
// cgindex precomputes `signed_elem` via elemissignedc; cgforrange
|
||
// precomputes `bind_signed[b]` via paramissigned. Same dispatch as
|
||
// tnodeloadop's tail; only the keying differs.
|
||
fn loadopsz(sigd: bool, sz: i32) str = {
|
||
if (sz == 1) { if (sigd) { return "MOVSBQ"; }; return "MOVZBQ"; };
|
||
if (sz == 2) { if (sigd) { return "MOVSWQ"; }; return "MOVZWQ"; };
|
||
if (sz == 4) { if (sigd) { return "MOVSXD"; }; return "MOVL"; };
|
||
return "MOVQ";
|
||
};
|
||
|
||
// localloadop — read instruction for a scalar local/let load. Same
|
||
// dispatch as fieldloadop, but keyed on the value's own tnode. Lets
|
||
// the caller emit MOVSXD/MOVSWQ/MOVSBQ on a signed-narrow slot instead
|
||
// of a raw MOVQ, so a slot that was last written by a narrow deref-
|
||
// store (`*p: *i32 = v` lowers to MOVL, only 4B) reads back as a
|
||
// properly-sign-extended i64. The natural N_ASSIGN / N_LET paths
|
||
// store the rhs as a sign-extended 8B word, so MOVQ accidentally
|
||
// works; deref-stores are the only path that touches fewer bytes
|
||
// than MOVQ reads. Mirror of cstage's localloadop in cmd/w6c/cgen.c.
|
||
// Resolves TBANG / TENUM / TNAME-alias chains so `type err = !i32`
|
||
// picks up size 4 the same way the cstage checker pre-computes
|
||
// t->size — without this, aliased narrows fall through to MOVQ.
|
||
export fn localloadop(c: *cgen, tnode: *node) str = {
|
||
let t: *node = tnode;
|
||
for (t != nil) {
|
||
let k: nkind = t.kind;
|
||
if (k == nkind.N_TBANG) { t = t.lhs; }
|
||
else { if (k == nkind.N_TENUM) { t = t.lhs; }
|
||
else { if (k == nkind.N_TNAME) {
|
||
let nm: str = t.str;
|
||
if (primsize(nm) > 0) { break; };
|
||
let al: *node = aliaslookup(c, nm);
|
||
if (al == nil) { break; };
|
||
t = al;
|
||
}
|
||
else { break; }; }; };
|
||
};
|
||
let sz: i32 = fieldsize(c, t);
|
||
if (sz != 1) { if (sz != 2) { if (sz != 4) { return "MOVQ"; }; }; };
|
||
let sigd: bool = fieldissignedc(c, tnode);
|
||
return loadopsz(sigd, sz);
|
||
};
|
||
|
||
// indexbaseesz — element size for `arr[i]` where the base is a
|
||
// chained-dot pseudo-field `s.ptr` (s being str/*str/slice/*slice).
|
||
// For str the element is one byte; for `[]T` / `*[]T` we drill into
|
||
// the slice element type.
|
||
fn indexbaseesz(c: *cgen, base: *node) i32 = {
|
||
if (base == nil) { return 8; };
|
||
if (base.kind != nkind.N_DOT) { return 8; };
|
||
let fld: str = base.str;
|
||
let inner: *node = base.lhs;
|
||
if (inner == nil) { return 8; };
|
||
if (inner.kind != nkind.N_IDENT) { return 8; };
|
||
let nm: str = inner.str;
|
||
let lc: *local = localfindnode(c, nm);
|
||
if (lc == nil) { return 8; };
|
||
let tn: *node = lc.tnode;
|
||
if (tn == nil) { return 8; };
|
||
|
||
// `.ptr` pseudo-field on str/slice → element of the str/slice.
|
||
if (streq(fld, "ptr")) {
|
||
let innert: *node = tn;
|
||
if (tn.kind == nkind.N_TPTR) { innert = tn.lhs; };
|
||
if (innert == nil) { return 8; };
|
||
if (innert.kind == nkind.N_TNAME) {
|
||
if (streq(innert.str, "str")) { return 1; };
|
||
};
|
||
if (innert.kind == nkind.N_TSLICE) { return elemsizeof(innert); };
|
||
return 8;
|
||
};
|
||
|
||
// Generic struct field: if it's *T, element size is T's size.
|
||
let lkind: nkind = tn.kind;
|
||
let sname: str;
|
||
sname.ptr = nil; sname.len = 0;
|
||
if (lkind == nkind.N_TNAME) { sname = tn.str; };
|
||
if (lkind == nkind.N_TPTR) {
|
||
let pinner: *node = tn.lhs;
|
||
if (pinner != nil) {
|
||
if (pinner.kind == nkind.N_TNAME) { sname = pinner.str; };
|
||
};
|
||
};
|
||
if (sname.len == 0) { return 8; };
|
||
let si: *structinfo = structlookup(c, sname);
|
||
if (si == nil) { return 8; };
|
||
let fi: *fieldinfo = si.fields;
|
||
for (fi != nil) {
|
||
let fn_: str = fi.fname;
|
||
if (streq(fn_, fld)) {
|
||
let ft: *node = fi.tnode;
|
||
if (ft == nil) { return 8; };
|
||
if (ft.kind == nkind.N_TPTR) {
|
||
let elem: *node = ft.lhs;
|
||
if (elem != nil) {
|
||
if (elem.kind == nkind.N_TNAME) {
|
||
if (streq(elem.str, "str")) { return 16; };
|
||
let ps: i32 = primsize(elem.str);
|
||
if (ps > 0) { return ps; };
|
||
};
|
||
};
|
||
return 8;
|
||
};
|
||
if (ft.kind == nkind.N_TSLICE) { return elemsizeof(ft); };
|
||
// str-typed field: indexing yields one byte
|
||
// (`n.s[i]` where .s is str — matches C cgen's
|
||
// MOVZBQ for byte indexing).
|
||
if (ft.kind == nkind.N_TNAME) {
|
||
if (streq(ft.str, "str")) { return 1; };
|
||
};
|
||
return 8;
|
||
};
|
||
fi = fi.finext;
|
||
};
|
||
return 8;
|
||
};
|
||
|
||
// dotinnerstructptr — for an nkind.N_DOT whose lhs is a chain of dots
|
||
// or an nkind.N_IDENT, walk the chain and return the nkind.N_TNAME tnode of the
|
||
// struct that the chain dereferences to (i.e., for `r.sym` where
|
||
// .sym is *lsym, return nkind.N_TNAME("lsym")). Returns nil if the chain
|
||
// doesn't resolve to a *struct.
|
||
//
|
||
// Used by the chained-DOT cgen path so `r.sym.val` knows the outer
|
||
// is a field of `lsym`.
|
||
fn dotinnerstructptr(c: *cgen, n: *node) *node = {
|
||
if (n == nil) { return nil; };
|
||
if (n.kind != nkind.N_DOT) { return nil; };
|
||
let base: *node = n.lhs;
|
||
let fld: str = n.str;
|
||
if (base == nil) { return nil; };
|
||
|
||
// Resolve base's struct tnode.
|
||
let baset: *node = nil;
|
||
if (base.kind == nkind.N_IDENT) {
|
||
let lc: *local = localfindnode(c, base.str);
|
||
if (lc == nil) { return nil; };
|
||
let tn: *node = lc.tnode;
|
||
if (tn == nil) { return nil; };
|
||
// base could be either struct-by-value (nkind.N_TNAME) or *struct (nkind.N_TPTR).
|
||
if (tn.kind == nkind.N_TNAME) { baset = tn; };
|
||
if (tn.kind == nkind.N_TPTR) { baset = tn.lhs; };
|
||
} else { if (base.kind == nkind.N_DOT) {
|
||
baset = dotinnerstructptr(c, base);
|
||
};};
|
||
if (baset == nil) { return nil; };
|
||
if (baset.kind != nkind.N_TNAME) { return nil; };
|
||
|
||
// Look up the struct, find the field, return the field's *struct.
|
||
let si: *structinfo = structlookup(c, baset.str);
|
||
if (si == nil) { return nil; };
|
||
let fi: *fieldinfo = si.fields;
|
||
for (fi != nil) {
|
||
if (streq(fi.fname, fld)) {
|
||
let ft: *node = fi.tnode;
|
||
if (ft == nil) { return nil; };
|
||
if (ft.kind != nkind.N_TPTR) { return nil; };
|
||
let inner: *node = ft.lhs;
|
||
if (inner == nil) { return nil; };
|
||
if (inner.kind != nkind.N_TNAME) { return nil; };
|
||
return inner;
|
||
};
|
||
fi = fi.finext;
|
||
};
|
||
return nil;
|
||
};
|
||
|
||
// elemsizeof — given the type node of an indexable (`*T`, `[]T`,
|
||
// `[N]T`, `str`), return the byte size of one element (1 for u8/i8/
|
||
// bool/str-byte, 8 otherwise — same shape as C cgen's esz fallback).
|
||
// For aliased element types (e.g. `[N]formattable`), callers that
|
||
// need the resolved slot size should use elemsizeofc(c, t) which
|
||
// follows aliases via slotsize.
|
||
fn elemsizeof(t: *node) i32 = {
|
||
if (t == nil) { return 1; };
|
||
let k: nkind = t.kind;
|
||
let elem: *node = nil;
|
||
if (k == nkind.N_TPTR) { elem = t.lhs; };
|
||
if (k == nkind.N_TSLICE) { elem = t.lhs; };
|
||
if (k == nkind.N_TARRAY) { elem = t.lhs; };
|
||
if (k == nkind.N_TNAME) {
|
||
let nm: str = t.str;
|
||
if (streq(nm, "str")) { return 1; };
|
||
// Indexing a primitive name (rare): element size = the prim.
|
||
let ps: i32 = primsize(nm);
|
||
if (ps > 0) { return ps; };
|
||
return 1;
|
||
};
|
||
if (elem == nil) { return 1; };
|
||
// `*[N]T`: drill through the pointer into the array's element so
|
||
// indexing scales by T's width, not the whole-array byte size.
|
||
if (elem.kind == nkind.N_TARRAY) {
|
||
if (elem.lhs != nil) { elem = elem.lhs; };
|
||
};
|
||
if (elem.kind == nkind.N_TNAME) {
|
||
let nm: str = elem.str;
|
||
// str element is 16B (ptr+len). primsize returns 0 for it.
|
||
if (streq(nm, "str")) { return 16; };
|
||
let ps: i32 = primsize(nm);
|
||
if (ps > 0) { return ps; };
|
||
};
|
||
return 8;
|
||
};
|
||
|
||
// elemsizeofc — like elemsizeof but resolves aliased element types
|
||
// (struct / tagged / `type foo = bar;`) via slotsize. Used where
|
||
// cgindex / cgassign need a correct stride for `[N]Alias` arrays
|
||
// whose Alias resolves to a tagged union (e.g. `[N]formattable`).
|
||
fn elemsizeofc(c: *cgen, t: *node) i32 = {
|
||
if (t == nil) { return 1; };
|
||
let direct: i32 = elemsizeof(t);
|
||
if (direct != 8) { return direct; };
|
||
let k: nkind = t.kind;
|
||
let elem: *node = nil;
|
||
if (k == nkind.N_TPTR) { elem = t.lhs; };
|
||
if (k == nkind.N_TSLICE) { elem = t.lhs; };
|
||
if (k == nkind.N_TARRAY) { elem = t.lhs; };
|
||
if (elem == nil) { return direct; };
|
||
if (elem.kind == nkind.N_TNAME) {
|
||
let ps: i32 = primsize(elem.str);
|
||
if (ps > 0) { return ps; };
|
||
};
|
||
return slotsize(c, elem);
|
||
};
|
||
|
||
// nodeisunsigned — best-effort cgen-time inference from the AST. We
|
||
// don't have a typed AST yet, so we walk surface nodes:
|
||
// nkind.N_INTLIT — never marked unsigned (no tsuffix plumbing yet)
|
||
// nkind.N_IDENT — look up the local's declared type
|
||
// nkind.N_DOT — look up the field's declared type via struct reg
|
||
// nkind.N_BIN / nkind.N_UN — recurse: unsigned if either operand is unsigned
|
||
// nkind.N_CAST — use the cast target type
|
||
//
|
||
// Conservative: if we can't tell, return false (signed). The cost of
|
||
// being wrong here is byte-different asm vs C, not bad runtime.
|
||
fn nodeisunsigned(c: *cgen, n: *node) bool = {
|
||
if (n == nil) { return false; };
|
||
let k: nkind = n.kind;
|
||
if (k == nkind.N_IDENT) {
|
||
let nm: str = n.str;
|
||
let lc: *local = localfindnode(c, nm);
|
||
if (lc != nil) { return typenodeisunsigned(lc.tnode); };
|
||
return false;
|
||
};
|
||
if (k == nkind.N_DOT) {
|
||
let base: *node = n.lhs;
|
||
let fld: str = n.str;
|
||
if (base != nil) {
|
||
if (base.kind == nkind.N_IDENT) {
|
||
let bn: str = base.str;
|
||
let lc: *local = localfindnode(c, bn);
|
||
if (lc != nil) {
|
||
let tn: *node = lc.tnode;
|
||
let lkind: nkind = nkind.N_NONE;
|
||
if (tn != nil) { lkind = tn.kind; };
|
||
let sname: str;
|
||
sname.ptr = nil; sname.len = 0;
|
||
if (lkind == nkind.N_TPTR) {
|
||
let inner: *node = tn.lhs;
|
||
if (inner != nil) {
|
||
if (inner.kind == nkind.N_TNAME) { sname = inner.str; };
|
||
};
|
||
};
|
||
if (lkind == nkind.N_TNAME) { sname = tn.str; };
|
||
if (sname.len > 0) {
|
||
let si: *structinfo = structlookup(c, sname);
|
||
if (si != nil) {
|
||
let fi: *fieldinfo = si.fields;
|
||
for (fi != nil) {
|
||
let fn_: str = fi.fname;
|
||
if (streq(fn_, fld)) {
|
||
return typenodeisunsigned(fi.tnode);
|
||
};
|
||
fi = fi.finext;
|
||
};
|
||
};
|
||
};
|
||
};
|
||
};
|
||
};
|
||
return false;
|
||
};
|
||
if (k == nkind.N_CAST) { return typenodeisunsigned(n.rhs); };
|
||
if (k == nkind.N_BIN) {
|
||
if (nodeisunsigned(c, n.lhs)) { return true; };
|
||
return nodeisunsigned(c, n.rhs);
|
||
};
|
||
if (k == nkind.N_UN) { return nodeisunsigned(c, n.lhs); };
|
||
// nkind.N_INDEX: `p[i]` is unsigned iff p's element type is unsigned.
|
||
// Walks the base local's declared type and pulls the element
|
||
// out — *u8 → u8, [N]u32 → u32, []u64 → u64. Without this the
|
||
// compare-codegen for `p[i] >= 48u8` falls back to signed JGE
|
||
// instead of JAE, diverging from C w6c on byte indexing.
|
||
if (k == nkind.N_INDEX) {
|
||
let base: *node = n.lhs;
|
||
if (base != nil) {
|
||
if (base.kind == nkind.N_IDENT) {
|
||
let lc: *local = localfindnode(c, base.str);
|
||
if (lc != nil) {
|
||
let tn: *node = lc.tnode;
|
||
if (tn != nil) {
|
||
let elem: *node = nil;
|
||
if (tn.kind == nkind.N_TPTR) { elem = tn.lhs; };
|
||
if (tn.kind == nkind.N_TARRAY) { elem = tn.lhs; };
|
||
if (tn.kind == nkind.N_TSLICE) { elem = tn.lhs; };
|
||
if (elem != nil) {
|
||
return typenodeisunsigned(elem);
|
||
};
|
||
};
|
||
};
|
||
};
|
||
};
|
||
return false;
|
||
};
|
||
return false;
|
||
};
|
||
|
||
// nodeprimwidth — primitive byte width of an expression, or 0 if not
|
||
// statically determinable. Mirrors nodeisunsigned's structural walk.
|
||
// Used by cgun TK_TILDE to clamp narrow unsigned ~ results to type
|
||
// width (NOTQ inverts the full 64-bit register).
|
||
fn nodeprimwidth(c: *cgen, n: *node) i32 = {
|
||
if (n == nil) { return 0; };
|
||
let k: nkind = n.kind;
|
||
if (k == nkind.N_IDENT) {
|
||
let lc: *local = localfindnode(c, n.str);
|
||
if (lc != nil) {
|
||
let tn: *node = lc.tnode;
|
||
if (tn != nil) {
|
||
if (tn.kind == nkind.N_TNAME) { return primsize(tn.str); };
|
||
};
|
||
};
|
||
return 0;
|
||
};
|
||
if (k == nkind.N_CAST) {
|
||
let tn: *node = n.rhs;
|
||
if (tn != nil) {
|
||
if (tn.kind == nkind.N_TNAME) { return primsize(tn.str); };
|
||
};
|
||
return 0;
|
||
};
|
||
if (k == nkind.N_UN) { return nodeprimwidth(c, n.lhs); };
|
||
return 0;
|
||
};
|
||
|
||
// ---- type-driven slot sizing ----------------------------------------
|
||
|
||
// structnaturalsize — type-natural size of `si`, i.e. max(foff +
|
||
// fsz) across declared fields. Mirrors cstage's `lu->size` for a
|
||
// TY_STRUCT (rounded only to the struct's maxalign).
|
||
//
|
||
// NOTE: si.totsize is mis-named — it's actually the *slot-padded*
|
||
// size (rounded up to 8 for stack-slot use; see registerstruct's
|
||
// tail `if ((off & 7) != 0) ...`). Frame allocation, [N]foo stride,
|
||
// and similar consumers want that slot-padded number. The
|
||
// receive-side ABI (#5) and any future "TYPE size, not slot size"
|
||
// query wants the natural size. Until si.totsize is split into
|
||
// si.naturalsize + si.slotsize (tracked as the wwstage-sizing
|
||
// follow-up task), recover the type-natural size from the field
|
||
// chain here.
|
||
fn structnaturalsize(si: *structinfo) i32 = {
|
||
if (si == nil) { return 0; };
|
||
let n: i32 = 0;
|
||
let fi: *fieldinfo = si.fields;
|
||
for (fi != nil) {
|
||
let end: i32 = fi.foff + fi.fsz;
|
||
if (end > n) { n = end; };
|
||
fi = fi.finext;
|
||
};
|
||
return n;
|
||
};
|
||
|
||
fn structlookup(c: *cgen, name: str) *structinfo = {
|
||
// Exact match first: bare-from-source struct names and already-
|
||
// leafed lookups hit here directly.
|
||
let s: *structinfo = c.structs;
|
||
for (s != nil) {
|
||
let sn: str = s.sname;
|
||
if (streq(sn, name)) { return s; };
|
||
s = s.sinext;
|
||
};
|
||
// Module-qualified form: `pkg.S` → match the leaf scoped to its
|
||
// originating module. Mirrors aliaslookup's mod-filter; the
|
||
// `smod == pkg` guard is what prevents two modules with same-
|
||
// leaf-name structs from collapsing into whichever entry appears
|
||
// first in the chain.
|
||
let i: i32 = name.len - 1;
|
||
for (i >= 0) {
|
||
if (name[i] == 46u8) { // '.'
|
||
let pkg: str;
|
||
pkg.ptr = name.ptr;
|
||
pkg.len = i;
|
||
let leaf: str;
|
||
leaf.ptr = name.ptr + ((i + 1): u64);
|
||
leaf.len = name.len - (i + 1);
|
||
let b: *structinfo = c.structs;
|
||
for (b != nil) {
|
||
if (streq(b.sname, leaf)) {
|
||
if (streq(b.smod, pkg)) {
|
||
return b;
|
||
};
|
||
};
|
||
b = b.sinext;
|
||
};
|
||
return nil;
|
||
};
|
||
i -= 1;
|
||
};
|
||
return nil;
|
||
};
|
||
|
||
// primsize — size in bytes of a primitive type name (or 0 if not
|
||
// recognised as a primitive — the caller falls back to other paths).
|
||
// fldnumidx — parse a tuple field name like "0" / "1" / "12" into an
|
||
// index, or -1 if not all-digits. Used by cgdot to dispatch
|
||
// `t.0` / `t.1` against an nkind.N_TTUPLE local without pulling in strconv.
|
||
fn fldnumidx(s: str) i32 = {
|
||
if (s.len == 0) { return -1; };
|
||
let r: i32 = 0;
|
||
let i: i32 = 0;
|
||
for (i < s.len) {
|
||
let b: u8 = s[i];
|
||
if (b < 48u8) { return -1; };
|
||
if (b > 57u8) { return -1; };
|
||
r = r * 10 + ((b - 48u8): i32);
|
||
i += 1;
|
||
};
|
||
return r;
|
||
};
|
||
|
||
fn primsize(name: str) i32 = {
|
||
if (streq(name, "u8")) { return 1; };
|
||
if (streq(name, "i8")) { return 1; };
|
||
if (streq(name, "bool")) { return 1; };
|
||
if (streq(name, "u16")) { return 2; };
|
||
if (streq(name, "i16")) { return 2; };
|
||
if (streq(name, "u32")) { return 4; };
|
||
if (streq(name, "i32")) { return 4; };
|
||
if (streq(name, "f32")) { return 4; };
|
||
if (streq(name, "u64")) { return 8; };
|
||
if (streq(name, "i64")) { return 8; };
|
||
if (streq(name, "uint")) { return 8; };
|
||
if (streq(name, "int")) { return 8; };
|
||
if (streq(name, "uintptr")) { return 8; };
|
||
if (streq(name, "f64")) { return 8; };
|
||
if (streq(name, "rune")) { return 4; };
|
||
if (streq(name, "void")) { return 0; };
|
||
return 0;
|
||
};
|
||
|
||
// variantnamematch — tagged-union variant names are compared as if
|
||
// they'd been alias-resolved. Pattern names can be module-qualified
|
||
// (`strconv.invalid` from a `case let e: strconv.invalid =>`),
|
||
// while the variant's declared name inside its own module is bare
|
||
// (`invalid`). With no checker the cgen can't follow imports, so we
|
||
// accept exact match plus suffix-after-`.` on either side. Mirrors
|
||
// the C cgen's type_eq, which goes through resolved Type pointers.
|
||
fn variantnamematch(vname: str, pname: str) bool = {
|
||
if (streq(vname, pname)) { return true; };
|
||
// `pname` is qualified, `vname` is bare: drop module prefix.
|
||
let i: i32 = 0;
|
||
for (i < pname.len) {
|
||
if (pname[i] == '.': u8) {
|
||
let tail: str;
|
||
tail.ptr = pname.ptr + i + 1;
|
||
tail.len = pname.len - i - 1;
|
||
if (streq(tail, vname)) { return true; };
|
||
};
|
||
i += 1;
|
||
};
|
||
// `vname` is qualified, `pname` is bare: same trick in reverse.
|
||
let j: i32 = 0;
|
||
for (j < vname.len) {
|
||
if (vname[j] == '.': u8) {
|
||
let tail: str;
|
||
tail.ptr = vname.ptr + j + 1;
|
||
tail.len = vname.len - j - 1;
|
||
if (streq(tail, pname)) { return true; };
|
||
};
|
||
j += 1;
|
||
};
|
||
return false;
|
||
};
|
||
|
||
// inferletcalltype — for an annotation-less `let x = expr;`, return
|
||
// a usable tnode for cgen's struct-aware paths. Today: `let x =
|
||
// f()?` infers x's type from the success variant of f's tagged
|
||
// return; without this, x has tnode = nil and `x.field` falls into
|
||
// the SB-symbol fallback (linker reports `undefined reference to
|
||
// <fieldname>`). We don't infer for plain `let x = f()` yet —
|
||
// non-tagged returns don't carry their type back the same way.
|
||
fn inferletcalltype(c: *cgen, rhs: *node) *node = {
|
||
if (rhs == nil) { return nil; };
|
||
// `?` (N_TRYPROP) and `!` (N_TRYUNW) both unwrap a tagged
|
||
// return to its success variant; the rhs we want the type of
|
||
// is the inner call expression.
|
||
let unwrap: bool = false;
|
||
let call: *node = rhs;
|
||
if (rhs.kind == nkind.N_TRYPROP) { call = rhs.lhs; unwrap = true; };
|
||
if (rhs.kind == nkind.N_TRYUNW) { call = rhs.lhs; unwrap = true; };
|
||
if (call == nil) { return nil; };
|
||
if (call.kind != nkind.N_CALL) { return nil; };
|
||
let callee: *node = call.lhs;
|
||
if (callee == nil) { return nil; };
|
||
let cname: str;
|
||
cname.ptr = nil; cname.len = 0;
|
||
if (callee.kind == nkind.N_IDENT) { cname = callee.str; };
|
||
if (callee.kind == nkind.N_DOT) { cname = callee.str; };
|
||
if (cname.len == 0) { return nil; };
|
||
let rt: *node = fnretlookup(c, cname);
|
||
if (rt == nil) { return nil; };
|
||
if (unwrap) {
|
||
// Strip error variants — success type is the first
|
||
// variant of the tagged return.
|
||
if (rt.kind != nkind.N_TTAGGED) { return nil; };
|
||
return rt.list;
|
||
};
|
||
// Plain call: declared return type is the local's type.
|
||
return rt;
|
||
};
|
||
|
||
// letslotsize — slot size for a `let` binding. Like slotsize, but
|
||
// detects `[_]T = arrlit;` (the type-AST has rhs == nil as the
|
||
// length-inferred sentinel) and computes count × element-size from
|
||
// the initialiser. Used by both scanlocals (prologue sizing) and
|
||
// cglet (slot alloc) so they agree on the frame layout.
|
||
//
|
||
// `let x = f();` (no annotation): infer from `f`'s declared return
|
||
// type so a 24B tagged-union return reserves all three spill slots,
|
||
// not the default 8B. Without this, the AX:DX:CX spill in cglet's
|
||
// tagged-init branch writes past the local and tramples the next
|
||
// slot.
|
||
export fn letslotsize(c: *cgen, n: *node) i32 = {
|
||
// `[_]T = arrlit;` — inferred-length array. slotsize would
|
||
// return elem_size * 1 (treating missing length as 1); intercept
|
||
// and compute the real count first.
|
||
if (n.lhs != nil) {
|
||
if (n.lhs.kind == nkind.N_TARRAY) {
|
||
if (n.lhs.rhs == nil) {
|
||
if (n.rhs != nil) {
|
||
if (n.rhs.kind == nkind.N_ARRLIT) {
|
||
let elemn: *node = n.lhs.lhs;
|
||
let esz: i32 = 8;
|
||
if (elemn != nil) {
|
||
if (elemn.kind == nkind.N_TNAME) {
|
||
let ps: i32 = primsize(elemn.str);
|
||
if (ps > 0) { esz = ps; };
|
||
};
|
||
};
|
||
let cnt: i32 = 0;
|
||
let e: *node = n.rhs.list;
|
||
for (e != nil) {
|
||
let adv: bool = true;
|
||
if (e.kind == nkind.N_FIELD) {
|
||
if (streq(e.str, "...")) {
|
||
e = nil;
|
||
adv = false;
|
||
};
|
||
};
|
||
if (adv) {
|
||
cnt += 1;
|
||
e = e.next;
|
||
};
|
||
};
|
||
return esz * cnt;
|
||
};
|
||
};
|
||
};
|
||
};
|
||
};
|
||
if (n.lhs != nil) { return slotsize(c, n.lhs); };
|
||
// Annotation-less init: defer to the call's return type if we
|
||
// can infer it. Tagged-union returns need 24B; everything else
|
||
// matches slotsize on the inferred type.
|
||
let inferred: *node = inferletcalltype(c, n.rhs);
|
||
if (inferred != nil) { return slotsize(c, inferred); };
|
||
return 8;
|
||
};
|
||
|
||
fn slotsize(c: *cgen, typn: *node) i32 = {
|
||
if (typn == nil) { return 8; };
|
||
let k: nkind = typn.kind;
|
||
if (k == nkind.N_TPTR) { return 8; };
|
||
if (k == nkind.N_TFN) { return 8; };
|
||
if (k == nkind.N_TCHAN) { return 8; };
|
||
if (k == nkind.N_TSLICE) { return 24; };
|
||
if (k == nkind.N_TTUPLE) {
|
||
// Sum element sizes. Mirrors C cgen which uses raw type
|
||
// sizes; padding to 8 happens inside slotsize for primitives,
|
||
// so a `(i64, str)` resolves to 8 + 16 = 24 (matches the C
|
||
// cgen 24B init / positional-access layout).
|
||
let total: i32 = 0;
|
||
let p: *node = typn.list;
|
||
for (p != nil) {
|
||
total += slotsize(c, p);
|
||
p = p.next;
|
||
};
|
||
return total;
|
||
};
|
||
if (k == nkind.N_TTAGGED){
|
||
// Nullable `(*T | void)` collapses to a single 8B pointer.
|
||
if (isnullabletype(typn)) { return 8; };
|
||
// Slot = 8 (tag) + max(variant payload sizes), rounded up
|
||
// to an 8-byte multiple so the reg-passing ABI (size/8
|
||
// words) doesn't drop the last value register. Mirrors C
|
||
// cgen's resolve_type for nkind.N_TTAGGED.
|
||
let v: *node = typn.list;
|
||
let maxsz: i32 = 0;
|
||
for (v != nil) {
|
||
let sz: i32 = slotsize(c, v);
|
||
if (sz > maxsz) { maxsz = sz; };
|
||
v = v.next;
|
||
};
|
||
let pad: i32 = (maxsz + 7) & ~7;
|
||
return 8 + pad;
|
||
};
|
||
if (k == nkind.N_TNAME) {
|
||
let nm: str = typn.str;
|
||
if (streq(nm, "str")) { return 16; };
|
||
let ps: i32 = primsize(nm);
|
||
if (ps > 0) {
|
||
// Pad to 8 for stack slots — matches C cgen which spills
|
||
// every primitive into an 8-byte slot.
|
||
return 8;
|
||
};
|
||
// Named struct lookup.
|
||
let si: *structinfo = structlookup(c, nm);
|
||
if (si != nil) { return si.totsize; };
|
||
// Type alias (`type foo = !str;` / `type foo = bar;`):
|
||
// follow it so a tagged-union variant of a !str-aliased
|
||
// error type contributes 16 bytes to the max payload
|
||
// rather than 8 (the default).
|
||
if (c != nil) {
|
||
let aliased: *node = aliaslookup(c, nm);
|
||
if (aliased != nil) {
|
||
if (aliased.kind == nkind.N_TBANG) {
|
||
return slotsize(c, aliased.lhs);
|
||
};
|
||
return slotsize(c, aliased);
|
||
};
|
||
};
|
||
return 8;
|
||
};
|
||
if (k == nkind.N_TARRAY) {
|
||
let lenn: *node = typn.rhs;
|
||
let elemn: *node = typn.lhs;
|
||
let elen: i64 = 1i64;
|
||
if (lenn != nil) {
|
||
if (lenn.kind == nkind.N_INTLIT) { elen = lenn.uval: i64; };
|
||
};
|
||
let esz: i32 = 8;
|
||
if (elemn != nil) {
|
||
if (elemn.kind == nkind.N_TNAME) {
|
||
let en: str = elemn.str;
|
||
let ps: i32 = primsize(en);
|
||
if (ps > 0) { esz = ps; }
|
||
else {
|
||
// Named struct / aliased type: size off
|
||
// the structinfo if present, else follow
|
||
// the alias via aliaslookup so
|
||
// `[N]formattable` reads the resolved
|
||
// tagged slot (e.g. 24B for
|
||
// `(i64|str|bool)`), not the fall-
|
||
// through 8B.
|
||
let si: *structinfo = structlookup(c, en);
|
||
if (si != nil) { esz = si.totsize; }
|
||
else { if (c != nil) {
|
||
let al: *node = aliaslookup(c, en);
|
||
if (al != nil) {
|
||
esz = slotsize(c, al);
|
||
};
|
||
}; };
|
||
};
|
||
} else { if (elemn.kind == nkind.N_TTAGGED) {
|
||
// Tagged-union element: full slot (8 tag +
|
||
// padded max payload). Matches C cgen's
|
||
// resolve_type for `[N]TAGGED`.
|
||
esz = slotsize(c, elemn);
|
||
} else { if (elemn.kind == nkind.N_TPTR) {
|
||
esz = 8;
|
||
} else { if (elemn.kind == nkind.N_TSTRUCT) {
|
||
esz = slotsize(c, elemn);
|
||
}; }; }; };
|
||
};
|
||
return (esz: i64 * elen): i32;
|
||
};
|
||
if (k == nkind.N_TSTRUCT) {
|
||
// Inline anonymous struct — sum of field sizes.
|
||
let f: *node = typn.list;
|
||
let total: i32 = 0;
|
||
for (f != nil) {
|
||
if (f.kind == nkind.N_TFIELD) {
|
||
total += slotsize(c, f.lhs);
|
||
};
|
||
f = f.next;
|
||
};
|
||
return total;
|
||
};
|
||
return 8;
|
||
};
|
||
|
||
// registerstruct — compute field offsets + total size for a struct
|
||
// type-decl, store in c.structs. Field type sizes use the same
|
||
// slotsize logic (with primitives kept at their natural width — we
|
||
// only round to 8 for stack slots, not struct interiors).
|
||
fn fieldsize(c: *cgen, tnode: *node) i32 = {
|
||
if (tnode == nil) { return 8; };
|
||
let k: nkind = tnode.kind;
|
||
if (k == nkind.N_TTAGGED){ return slotsize(c, tnode); };
|
||
if (k == nkind.N_TNAME) {
|
||
let nm: str = tnode.str;
|
||
if (streq(nm, "str")) { return 16; };
|
||
let ps: i32 = primsize(nm);
|
||
if (ps > 0) { return ps; };
|
||
let si: *structinfo = structlookup(c, nm);
|
||
if (si != nil) { return si.totsize; };
|
||
// Enum: size of its storage type. Mirrors the C cgen, which
|
||
// reads Type.size off the TY_ENUM (which inherits from .sub).
|
||
let en: *enumtype = enumlookup(c, nm);
|
||
if (en != nil) {
|
||
if (en.storage != nil) {
|
||
if (en.storage.kind == nkind.N_TNAME) {
|
||
let sps: i32 = primsize(en.storage.str);
|
||
if (sps > 0) { return sps; };
|
||
};
|
||
};
|
||
return 4; // default storage is i32
|
||
};
|
||
// Type alias to a tagged-union — recurse through aliaslookup
|
||
// so `e: ev` (where `ev = (i64 | i32)`) takes 16B in the
|
||
// containing struct rather than the 8B default.
|
||
if (c != nil) {
|
||
let aliased: *node = aliaslookup(c, nm);
|
||
if (aliased != nil) { return fieldsize(c, aliased); };
|
||
};
|
||
return 8;
|
||
};
|
||
if (k == nkind.N_TPTR) { return 8; };
|
||
if (k == nkind.N_TSLICE) { return 24; };
|
||
if (k == nkind.N_TARRAY) {
|
||
// Same shape as slotsize's TARRAY branch.
|
||
let lenn: *node = tnode.rhs;
|
||
let elemn: *node = tnode.lhs;
|
||
let elen: i64 = 1i64;
|
||
if (lenn != nil) {
|
||
if (lenn.kind == nkind.N_INTLIT) { elen = lenn.uval: i64; };
|
||
};
|
||
let esz: i32 = fieldsize(c, elemn);
|
||
return (esz: i64 * elen): i32;
|
||
};
|
||
return 8;
|
||
};
|
||
|
||
fn registerstruct(c: *cgen, name: str, module: str, tstruct: *node) void = {
|
||
let si: *structinfo = amalloc(c.a, 80u64): *structinfo;
|
||
si.sname = name;
|
||
si.smod = module;
|
||
si.fields = nil;
|
||
si.totsize = 0;
|
||
let head: *fieldinfo = nil;
|
||
let tail: *fieldinfo = nil;
|
||
let off: i32 = 0;
|
||
let f: *node = tstruct.list;
|
||
for (f != nil) {
|
||
if (f.kind == nkind.N_TFIELD) {
|
||
let sz: i32 = fieldsize(c, f.lhs);
|
||
// Align to 8 for any field >= 4 bytes (matches our other
|
||
// cgen choices). i8/u8/bool may sit on odd byte offsets;
|
||
// the C cgen does similar best-effort packing.
|
||
let aln: i32 = 1;
|
||
if (sz >= 8) { aln = 8; }
|
||
else { if (sz >= 4) { aln = 4; }
|
||
else { if (sz >= 2) { aln = 2; }; }; };
|
||
if ((off & (aln - 1)) != 0) {
|
||
off = (off + aln - 1) & ~(aln - 1);
|
||
};
|
||
let fi: *fieldinfo = amalloc(c.a, 48u64): *fieldinfo;
|
||
fi.fname = f.str;
|
||
fi.foff = off;
|
||
fi.fsz = sz;
|
||
fi.tnode = f.lhs;
|
||
if (head == nil) { head = fi; tail = fi; }
|
||
else { tail.finext = fi; tail = fi; };
|
||
off += sz;
|
||
};
|
||
f = f.next;
|
||
};
|
||
// Round total to 8 for stack-slot use.
|
||
if ((off & 7) != 0) { off = (off + 7) & ~7; };
|
||
si.fields = head;
|
||
si.totsize = off;
|
||
si.sinext = c.structs;
|
||
c.structs = si;
|
||
};
|
||
|
||
fn collectstructs(c: *cgen, file: *node) void = {
|
||
c.structs = nil;
|
||
if (file == nil) { return; };
|
||
let d: *node = file.list;
|
||
for (d != nil) {
|
||
if (d.kind == nkind.N_TYPEDECL) {
|
||
let body: *node = d.lhs;
|
||
if (body != nil) {
|
||
if (body.kind == nkind.N_TSTRUCT) {
|
||
registerstruct(c, d.str, d.module, body);
|
||
};
|
||
};
|
||
};
|
||
d = d.next;
|
||
};
|
||
};
|
||
|
||
// `type X = str;` aliases) to `str`. Takes *cgen so it can walk the
|
||
// alias chain registered at file load.
|
||
fn isstrtyperaw(t: *node) bool = {
|
||
if (t == nil) { return false; };
|
||
if (t.kind == nkind.N_TNAME) {
|
||
let nm: str = t.str;
|
||
if (streq(nm, "str")) { return true; };
|
||
};
|
||
return false;
|
||
};
|
||
|
||
fn isstrtype(c: *cgen, t: *node) bool = {
|
||
if (isstrtyperaw(t)) { return true; };
|
||
if (c == nil) { return false; };
|
||
let r: *node = resolvetype(c, t);
|
||
if (isstrtyperaw(r)) { return true; };
|
||
// `parserr = !str` — `!T` aliases shouldn't hide their
|
||
// underlying type from str-routing. Unwrap and re-check.
|
||
if (r != nil) {
|
||
if (r.kind == nkind.N_TBANG) {
|
||
let inner: *node = r.lhs;
|
||
if (isstrtyperaw(inner)) { return true; };
|
||
if (inner != nil) {
|
||
let r2: *node = resolvetype(c, inner);
|
||
if (isstrtyperaw(r2)) { return true; };
|
||
};
|
||
};
|
||
};
|
||
return false;
|
||
};
|
||
|
||
fn isslicetyperaw(t: *node) bool = {
|
||
if (t == nil) { return false; };
|
||
if (t.kind == nkind.N_TSLICE) { return true; };
|
||
return false;
|
||
};
|
||
|
||
fn isslicetype(c: *cgen, t: *node) bool = {
|
||
if (isslicetyperaw(t)) { return true; };
|
||
if (c == nil) { return false; };
|
||
let r: *node = resolvetype(c, t);
|
||
return isslicetyperaw(r);
|
||
};
|
||
|
||
fn istaggedtyperaw(t: *node) bool = {
|
||
if (t == nil) { return false; };
|
||
if (t.kind == nkind.N_TTAGGED) { return true; };
|
||
return false;
|
||
};
|
||
|
||
// resolvetagged — return the underlying N_TTAGGED node for `t`, or nil
|
||
// if `t` doesn't ultimately denote a tagged union. Follows N_TNAME
|
||
// aliases (via resolvetype) and unwraps one leading N_TBANG so
|
||
// `type error = !(invalid | overflow);` resolves to its inner
|
||
// `(invalid | overflow)` node. Use at sites that read variant lists
|
||
// or detect nullable folding off a scrutinee — cgmatch, cgtypetest,
|
||
// cgtypeassert — so aliased `!(A|B)` shapes still dispatch.
|
||
export fn resolvetagged(c: *cgen, t: *node) *node = {
|
||
let r: *node = resolvetype(c, t);
|
||
if (r == nil) { return nil; };
|
||
if (r.kind == nkind.N_TBANG) {
|
||
let inner: *node = r.lhs;
|
||
if (inner == nil) { return nil; };
|
||
r = resolvetype(c, inner);
|
||
if (r == nil) { return nil; };
|
||
};
|
||
if (r.kind == nkind.N_TTAGGED) { return r; };
|
||
return nil;
|
||
};
|
||
|
||
// istaggedtype — alias-aware. Mirrors isstrtype: follow N_TNAME to its
|
||
// underlying decl, then unwrap a leading N_TBANG so `type error =
|
||
// !(invalid | overflow);` is still recognised as tagged. Without the
|
||
// bang unwrap the prologue treats the param as scalar (8B), spilling
|
||
// only DI and losing the value-word SI; the match read of slot+8 then
|
||
// trails into saved BP.
|
||
fn istaggedtype(c: *cgen, t: *node) bool = {
|
||
if (istaggedtyperaw(t)) { return true; };
|
||
if (c == nil) { return false; };
|
||
let r: *node = resolvetype(c, t);
|
||
if (istaggedtyperaw(r)) { return true; };
|
||
if (r != nil) {
|
||
if (r.kind == nkind.N_TBANG) {
|
||
let inner: *node = r.lhs;
|
||
if (istaggedtyperaw(inner)) { return true; };
|
||
if (inner != nil) {
|
||
let r2: *node = resolvetype(c, inner);
|
||
if (istaggedtyperaw(r2)) { return true; };
|
||
};
|
||
};
|
||
};
|
||
return false;
|
||
};
|
||
|
||
// isf32typeraw / isf64typeraw — bare TNAME check, no alias resolution.
|
||
fn isf32typeraw(t: *node) bool = {
|
||
if (t == nil) { return false; };
|
||
if (t.kind != nkind.N_TNAME) { return false; };
|
||
return streq(t.str, "f32");
|
||
};
|
||
|
||
fn isf64typeraw(t: *node) bool = {
|
||
if (t == nil) { return false; };
|
||
if (t.kind != nkind.N_TNAME) { return false; };
|
||
return streq(t.str, "f64");
|
||
};
|
||
|
||
// isfloattype — f32 / f64 (and aliases of those). Used by cglet,
|
||
// cgident, cgassign, cgbin, cgcast, cgcall, cgreturn, fn-prologue to
|
||
// dispatch the MOVSS/MOVSD-shaped paths.
|
||
export fn isfloattype(c: *cgen, t: *node) bool = {
|
||
if (isf32typeraw(t)) { return true; };
|
||
if (isf64typeraw(t)) { return true; };
|
||
if (c == nil) { return false; };
|
||
let r: *node = resolvetype(c, t);
|
||
if (isf32typeraw(r)) { return true; };
|
||
if (isf64typeraw(r)) { return true; };
|
||
return false;
|
||
};
|
||
|
||
// isf32type — narrower predicate: true only for f32 (after alias
|
||
// resolution). f64 returns false. Used to pick MOVSS vs MOVSD and
|
||
// the SS-variant arithmetic / cast opcodes.
|
||
export fn isf32type(c: *cgen, t: *node) bool = {
|
||
if (isf32typeraw(t)) { return true; };
|
||
if (c == nil) { return false; };
|
||
let r: *node = resolvetype(c, t);
|
||
return isf32typeraw(r);
|
||
};
|
||
|
||
// exprfloatkind — classify an expression's value-class so callers can
|
||
// pick float vs integer codegen without a full type system. Returns:
|
||
// 0 — integer-like (or unknown — same fallback the existing cgen
|
||
// takes today)
|
||
// 1 — f32
|
||
// 2 — f64
|
||
// Recognises: float literals, idents bound to float lets/locals,
|
||
// chained casts whose target is float, and (recursively) the inner
|
||
// expr of a non-narrowing wrapping construct. Anything we can't
|
||
// pin down conservatively reports integer — the worst case is that
|
||
// CVT* is skipped for an exotic case the user can still spell with
|
||
// an explicit local.
|
||
export fn exprfloatkind(c: *cgen, n: *node) i32 = {
|
||
if (n == nil) { return 0; };
|
||
let k: nkind = n.kind;
|
||
if (k == nkind.N_FLOATLIT) { return 2; };
|
||
if (k == nkind.N_CAST) {
|
||
if (isf32type(c, n.rhs)) { return 1; };
|
||
if (isfloattype(c, n.rhs)) { return 2; };
|
||
return 0;
|
||
};
|
||
if (k == nkind.N_IDENT) {
|
||
let lc: *local = localfindnode(c, n.str);
|
||
if (lc != nil) {
|
||
if (isf32type(c, lc.tnode)) { return 1; };
|
||
if (isfloattype(c, lc.tnode)) { return 2; };
|
||
return 0;
|
||
};
|
||
let lv: *letvar = c.lets;
|
||
for (lv != nil) {
|
||
if (streq(lv.name, n.str)) {
|
||
if (isf32type(c, lv.tnode)) { return 1; };
|
||
if (isfloattype(c, lv.tnode)) { return 2; };
|
||
return 0;
|
||
};
|
||
lv = lv.lvnext;
|
||
};
|
||
return 0;
|
||
};
|
||
if (k == nkind.N_UN) {
|
||
// Unary on a float (TK_MINUS) returns float; everything
|
||
// else is integer-coded.
|
||
if (n.op == tkind.TK_MINUS) {
|
||
return exprfloatkind(c, n.lhs);
|
||
};
|
||
return 0;
|
||
};
|
||
if (k == nkind.N_BIN) {
|
||
// Arithmetic binops inherit the operands' kind. Comparison
|
||
// (eq/ne/lt/...) returns bool — integer.
|
||
let op: tkind = n.op;
|
||
if (op == tkind.TK_PLUS) { return exprfloatkind(c, n.lhs); };
|
||
if (op == tkind.TK_MINUS) { return exprfloatkind(c, n.lhs); };
|
||
if (op == tkind.TK_STAR) { return exprfloatkind(c, n.lhs); };
|
||
if (op == tkind.TK_SLASH) { return exprfloatkind(c, n.lhs); };
|
||
return 0;
|
||
};
|
||
if (k == nkind.N_CALL) {
|
||
// Look up the callee's declared return type — fnretlookup
|
||
// returns the type-AST. Routes float-returning fns through
|
||
// the X0 ABI so cglet / cgassign know to spill from X0.
|
||
let nm: str;
|
||
nm.ptr = nil; nm.len = 0;
|
||
if (n.lhs != nil) {
|
||
if (n.lhs.kind == nkind.N_IDENT) { nm = n.lhs.str; };
|
||
};
|
||
if (nm.len > 0) {
|
||
let rt: *node = fnretlookup(c, nm);
|
||
if (isf32type(c, rt)) { return 1; };
|
||
if (isfloattype(c, rt)) { return 2; };
|
||
};
|
||
return 0;
|
||
};
|
||
if (k == nkind.N_DOT) {
|
||
// `p.field` where the struct field is f64/f32. Without this,
|
||
// `v.fval: i64` lowers to CVTSI on an integer-load value
|
||
// instead of CVTTSD2SI on the X0 the cgdot path actually
|
||
// emits for an f64 field.
|
||
let base: *node = n.lhs;
|
||
let fld: str = n.str;
|
||
if (base != nil) {
|
||
let sname: str;
|
||
sname.ptr = nil; sname.len = 0;
|
||
if (base.kind == nkind.N_IDENT) {
|
||
let lc: *local = localfindnode(c, base.str);
|
||
if (lc != nil) {
|
||
let tn: *node = lc.tnode;
|
||
if (tn != nil) {
|
||
if (tn.kind == nkind.N_TNAME) { sname = tn.str; };
|
||
if (tn.kind == nkind.N_TPTR) {
|
||
let pe: *node = tn.lhs;
|
||
if (pe != nil) {
|
||
if (pe.kind == nkind.N_TNAME) { sname = pe.str; };
|
||
};
|
||
};
|
||
};
|
||
};
|
||
};
|
||
if (sname.len > 0) {
|
||
let si: *structinfo = structlookup(c, sname);
|
||
if (si != nil) {
|
||
let fi: *fieldinfo = si.fields;
|
||
for (fi != nil) {
|
||
if (streq(fi.fname, fld)) {
|
||
if (isf32type(c, fi.tnode)) { return 1; };
|
||
if (isfloattype(c, fi.tnode)) { return 2; };
|
||
return 0;
|
||
};
|
||
fi = fi.finext;
|
||
};
|
||
};
|
||
};
|
||
};
|
||
return 0;
|
||
};
|
||
return 0;
|
||
};
|
||
|
||
// isnullabletype — nkind.N_TTAGGED with exactly two children, one *T and
|
||
// one `void`. Folds to a single 8-byte pointer slot per Hare's
|
||
// `(*T | null)` semantics. Mirrors check.c's resolve_type detection.
|
||
export fn isnullabletype(t: *node) bool = {
|
||
if (t == nil) { return false; };
|
||
if (t.kind != nkind.N_TTAGGED) { return false; };
|
||
let a: *node = t.list;
|
||
if (a == nil) { return false; };
|
||
let b: *node = a.next;
|
||
if (b == nil) { return false; };
|
||
if (b.next != nil) { return false; };
|
||
let aptr: bool = (a.kind == nkind.N_TPTR);
|
||
let bptr: bool = (b.kind == nkind.N_TPTR);
|
||
let avoid: bool = (a.kind == nkind.N_TNAME);
|
||
if (avoid) { avoid = streq(a.str, "void"); };
|
||
let bvoid: bool = (b.kind == nkind.N_TNAME);
|
||
if (bvoid) { bvoid = streq(b.str, "void"); };
|
||
if (aptr) { if (bvoid) { return true; }; };
|
||
if (avoid) { if (bptr) { return true; }; };
|
||
return false;
|
||
};
|
||
|
||
// nullableptrtag — 0-based index of the *T variant in a nullable
|
||
// union. The void variant takes the other slot (0 or 1).
|
||
export fn nullableptrtag(t: *node) i32 = {
|
||
if (t == nil) { return 0; };
|
||
if (t.kind != nkind.N_TTAGGED) { return 0; };
|
||
let a: *node = t.list;
|
||
if (a != nil) { if (a.kind == nkind.N_TPTR) { return 0; }; };
|
||
return 1;
|
||
};
|
||
|
||
// voidvariantindex — find the 0-based index of the `void` variant in a
|
||
// tagged-union type expr, -1 if absent. Used by cgreturn to map bare
|
||
// `return;` in a tagged-union-returning fn to the void variant's tag.
|
||
fn voidvariantindex(tagged: *node) i32 = {
|
||
if (tagged == nil) { return -1; };
|
||
if (tagged.kind != nkind.N_TTAGGED) { return -1; };
|
||
let v: *node = tagged.list;
|
||
let idx: i32 = 0;
|
||
for (v != nil) {
|
||
if (v.kind == nkind.N_TNAME) {
|
||
if (streq(v.str, "void")) { return idx; };
|
||
};
|
||
v = v.next;
|
||
idx += 1;
|
||
};
|
||
return -1;
|
||
};
|
||
|
||
// rhstargetname — for a returned value, what's its declared (or
|
||
// surface-inferred) type name? `expr: T` casts dictate T directly;
|
||
// bare strlit/intlit fall back to a primitive name.
|
||
fn rhstargetname(c: *cgen, rhs: *node) str = {
|
||
let nm: str;
|
||
nm.ptr = nil; nm.len = 0;
|
||
if (rhs == nil) { return nm; };
|
||
// Unary `-` / `+` / `~` inherit the inner expression's type:
|
||
// cstage's checker stamps N_UN's type from cunop's inner walk,
|
||
// so `-42i64` is ty_i64 there. Wwstage has no checker stage —
|
||
// peel the operator here so a typed-int literal under a sign
|
||
// reaches its tsuffix branch below instead of falling into
|
||
// taggedvariantindex's "first non-str variant" fallback. Mirror
|
||
// of cmd/wcc/check.c cunop TK_MINUS/PLUS/TILDE returning t.
|
||
if (rhs.kind == nkind.N_UN) {
|
||
let op: tkind = rhs.op;
|
||
if (op == tkind.TK_MINUS || op == tkind.TK_PLUS
|
||
|| op == tkind.TK_TILDE) {
|
||
if (rhs.lhs != nil) {
|
||
return rhstargetname(c, rhs.lhs);
|
||
};
|
||
};
|
||
};
|
||
if (rhs.kind == nkind.N_CAST) {
|
||
let t: *node = rhs.rhs;
|
||
if (t != nil) {
|
||
if (t.kind == nkind.N_TNAME) { return t.str; };
|
||
};
|
||
return nm;
|
||
};
|
||
if (rhs.kind == nkind.N_STRLIT) { return "str"; };
|
||
if (rhs.kind == nkind.N_TRUE) { return "bool"; };
|
||
if (rhs.kind == nkind.N_FALSE) { return "bool"; };
|
||
if (rhs.kind == nkind.N_RUNELIT) { return "rune"; };
|
||
if (rhs.kind == nkind.N_INTLIT) {
|
||
// Typed int literal (`42i64`, `3u8`): suffix names the
|
||
// concrete variant so flatvariantidx finds it. Untyped
|
||
// literals (tsuffix=="") fall through to the isstr scan.
|
||
let s: str = rhs.tsuffix;
|
||
if (s.len > 0) { return s; };
|
||
};
|
||
// `T{}` carries its type name on the lhs N_IDENT — the parser
|
||
// builds `N_STRUCTLIT{ lhs = N_IDENT("T"), list = fields }`.
|
||
// Needed so `return eof{};` (variant of a tagged union) resolves
|
||
// to the `eof` variant index rather than falling through to the
|
||
// "first non-str variant" fallback in taggedvariantindex.
|
||
if (rhs.kind == nkind.N_STRUCTLIT) {
|
||
let tref: *node = rhs.lhs;
|
||
if (tref != nil) {
|
||
if (tref.kind == nkind.N_IDENT) { return tref.str; };
|
||
if (tref.kind == nkind.N_TNAME) { return tref.str; };
|
||
};
|
||
return nm;
|
||
};
|
||
if (rhs.kind == nkind.N_IDENT) {
|
||
let lc: *local = localfindnode(c, rhs.str);
|
||
if (lc != nil) {
|
||
let tn: *node = lc.tnode;
|
||
if (tn != nil) {
|
||
if (tn.kind == nkind.N_TNAME) { return tn.str; };
|
||
};
|
||
};
|
||
};
|
||
return nm;
|
||
};
|
||
|
||
// taggedvariantindex — given the tagged-union type expr and the
|
||
// returned value's surface type, find the matching variant's 0-based
|
||
// index. Compare by exact type name first; if no match, fall back to
|
||
// "any str-shape variant matches an str-typed value".
|
||
fn taggedvariantindex(c: *cgen, tagged: *node, rhs: *node) i32 = {
|
||
if (tagged == nil) { return -1; };
|
||
if (rhs == nil) { return -1; };
|
||
let wantname: str = rhstargetname(c, rhs);
|
||
if (wantname.len > 0) {
|
||
let r: i32 = flatvariantidx(c, tagged, wantname);
|
||
if (r >= 0) { return r; };
|
||
};
|
||
// Fallback: by str-shape (resolves aliases). Walks the
|
||
// spread-flattened variant list so a `(...inner | str)` outer
|
||
// agrees with the (i32 | str) inner's str position.
|
||
let wantstr: bool = nodeisstr(c, rhs);
|
||
let v: *node = tagged.list;
|
||
let idx: i32 = 0;
|
||
for (v != nil) {
|
||
let isspread: bool = (v.op == tkind.TK_ELLIPSIS);
|
||
if (isspread) {
|
||
let inner: *node = v;
|
||
if (inner.kind == nkind.N_TNAME) {
|
||
let a: *node = aliaslookup(c, inner.str);
|
||
if (a != nil) { inner = a; };
|
||
};
|
||
if (inner != nil) {
|
||
if (inner.kind == nkind.N_TTAGGED) {
|
||
let iv: *node = inner.list;
|
||
for (iv != nil) {
|
||
let ivisstr: bool = false;
|
||
if (iv.kind == nkind.N_TNAME) {
|
||
if (isstrtype(c, iv)) { ivisstr = true; };
|
||
};
|
||
if (ivisstr == wantstr) { return idx; };
|
||
iv = iv.next;
|
||
idx += 1;
|
||
};
|
||
v = v.next;
|
||
continue;
|
||
};
|
||
};
|
||
};
|
||
let visstr: bool = false;
|
||
if (v.kind == nkind.N_TNAME) {
|
||
if (isstrtype(c, v)) { visstr = true; };
|
||
};
|
||
if (visstr == wantstr) { return idx; };
|
||
v = v.next;
|
||
idx += 1;
|
||
};
|
||
return -1;
|
||
};
|
||
|
||
// flatvariantidx — walk `tagged`'s variant list (with spread `...inner`
|
||
// expansion) and return the flat 0-based index where `want` matches.
|
||
// Mirrors check.c's spread flatten at type resolution: an outer
|
||
// `(...inner | T)` has the inner's variants inlined in declaration
|
||
// order, so the tag indices stay in sync between cstage (which
|
||
// resolves types upfront) and wwstage (which doesn't). Returns -1 if
|
||
// no variant matches.
|
||
fn flatvariantidx(c: *cgen, tagged: *node, want: str) i32 = {
|
||
if (tagged == nil) { return -1; };
|
||
if (tagged.kind != nkind.N_TTAGGED) { return -1; };
|
||
if (want.len == 0) { return -1; };
|
||
let v: *node = tagged.list;
|
||
let idx: i32 = 0;
|
||
for (v != nil) {
|
||
let isspread: bool = (v.op == tkind.TK_ELLIPSIS);
|
||
if (isspread) {
|
||
let inner: *node = v;
|
||
if (inner.kind == nkind.N_TNAME) {
|
||
let a: *node = aliaslookup(c, inner.str);
|
||
if (a != nil) { inner = a; };
|
||
};
|
||
if (inner != nil) {
|
||
if (inner.kind == nkind.N_TTAGGED) {
|
||
let iv: *node = inner.list;
|
||
for (iv != nil) {
|
||
if (iv.kind == nkind.N_TNAME) {
|
||
if (variantnamematch(iv.str, want)) {
|
||
return idx;
|
||
};
|
||
};
|
||
iv = iv.next;
|
||
idx += 1;
|
||
};
|
||
v = v.next;
|
||
continue;
|
||
};
|
||
};
|
||
};
|
||
if (v.kind == nkind.N_TNAME) {
|
||
if (variantnamematch(v.str, want)) { return idx; };
|
||
};
|
||
v = v.next;
|
||
idx += 1;
|
||
};
|
||
return -1;
|
||
};
|
||
|
||
// cgwidentagremap — when widening from one tagged union to a wider one,
|
||
// rewrite the source's variant tag at slot_off+0 to use the destination's
|
||
// variant indices. No-op when src and dst index orders coincide.
|
||
// Mirrors cg_widen_tag_remap in cmd/w6c/cgen.c.
|
||
fn cgwidentagremap(c: *cgen, dst: *node, src: *node, slot_off: i32) void = {
|
||
if (dst == nil) { return; };
|
||
if (src == nil) { return; };
|
||
if (dst.kind != nkind.N_TTAGGED) { return; };
|
||
if (src.kind != nkind.N_TTAGGED) { return; };
|
||
let identity: bool = true;
|
||
let v: *node = src.list;
|
||
let idx: i32 = 0;
|
||
for (v != nil) {
|
||
let di: i32 = cgtagvariantidx(c, dst, v);
|
||
if (di < 0) { di = 0; };
|
||
if (di != idx) { identity = false; v = nil; }
|
||
else { v = v.next; idx += 1; };
|
||
};
|
||
if (identity) { return; };
|
||
let done: str = mklabel(c, "remap_done");
|
||
emitline("\tMOVQ\t");
|
||
emitoff(slot_off: i64);
|
||
emitline("(BP), AX\n");
|
||
v = src.list;
|
||
idx = 0;
|
||
for (v != nil) {
|
||
let next: str = mklabel(c, "remap_next");
|
||
let di: i32 = cgtagvariantidx(c, dst, v);
|
||
if (di < 0) { di = 0; };
|
||
emitline("\tCMPQ\t$");
|
||
emitint(idx: i64);
|
||
emitline(", AX\n");
|
||
emitline("\tJNE\t");
|
||
emitline(next);
|
||
emitline("\n");
|
||
emitline("\tMOVQ\t$");
|
||
emitint(di: i64);
|
||
emitline(", AX\n");
|
||
emitline("\tMOVQ\tAX, ");
|
||
emitoff(slot_off: i64);
|
||
emitline("(BP)\n");
|
||
emitline("\tJMP\t");
|
||
emitline(done);
|
||
emitline("\n");
|
||
emitlabel(next);
|
||
v = v.next;
|
||
idx += 1;
|
||
};
|
||
emitlabel(done);
|
||
return;
|
||
};
|
||
|
||
// rhsisstructpayload — is `src` a struct value (literal or local ident
|
||
// of a struct type)? Returns the struct name, or empty str. Only true
|
||
// when the name is registered in c.structs — `!void` / `!i32` aliases
|
||
// share the N_STRUCTLIT / N_TNAME shape but aren't structs, and must
|
||
// fall through to the scalar/str/tagged-source paths instead.
|
||
fn rhsstructpayload(c: *cgen, src: *node) str = {
|
||
let empty: str;
|
||
empty.ptr = nil; empty.len = 0;
|
||
if (src == nil) { return empty; };
|
||
if (src.kind == nkind.N_STRUCTLIT) {
|
||
let trefn: *node = src.lhs;
|
||
if (trefn != nil) {
|
||
let nm: str;
|
||
nm.ptr = nil; nm.len = 0;
|
||
if (trefn.kind == nkind.N_IDENT) { nm = trefn.str; };
|
||
if (trefn.kind == nkind.N_TNAME) { nm = trefn.str; };
|
||
if (nm.len > 0) {
|
||
if (structlookup(c, nm) != nil) { return nm; };
|
||
};
|
||
};
|
||
return empty;
|
||
};
|
||
if (src.kind == nkind.N_IDENT) {
|
||
let lc: *local = localfindnode(c, src.str);
|
||
if (lc != nil) {
|
||
let tn: *node = lc.tnode;
|
||
if (tn != nil) {
|
||
if (tn.kind == nkind.N_TNAME) {
|
||
if (structlookup(c, tn.str) != nil) {
|
||
return tn.str;
|
||
};
|
||
};
|
||
};
|
||
};
|
||
};
|
||
return empty;
|
||
};
|
||
|
||
// rhstaggedsource — return the tagged-type node for `src` when src is a
|
||
// tagged-typed local ident; nil otherwise. The slot-copy path uses this
|
||
// to walk variants for tag remap.
|
||
fn rhstaggedident(c: *cgen, src: *node) *node = {
|
||
if (src == nil) { return nil; };
|
||
if (src.kind != nkind.N_IDENT) { return nil; };
|
||
let lc: *local = localfindnode(c, src.str);
|
||
if (lc == nil) { return nil; };
|
||
let tn: *node = lc.tnode;
|
||
if (!istaggedtype(c, tn)) { return nil; };
|
||
return resolvetagged(c, tn);
|
||
};
|
||
|
||
// dotfieldtnode — for an N_DOT src whose base is a local ident or
|
||
// *struct, return the declared type node of the named field, or nil
|
||
// if the shape doesn't resolve (e.g. enum-member access, pseudo-
|
||
// field `.len`, top-level global). Used by rhstaggedabicall and
|
||
// related predicates to walk into the field's tagged type.
|
||
fn dotfieldtnode(c: *cgen, n: *node) *node = {
|
||
if (n == nil) { return nil; };
|
||
if (n.kind != nkind.N_DOT) { return nil; };
|
||
let base: *node = n.lhs;
|
||
let fld: str = n.str;
|
||
if (base == nil) { return nil; };
|
||
if (base.kind != nkind.N_IDENT) { return nil; };
|
||
let lc: *local = localfindnode(c, base.str);
|
||
let btn: *node = nil;
|
||
if (lc != nil) { btn = lc.tnode; }
|
||
else { btn = letvartnode(c, base.str); };
|
||
if (btn == nil) { return nil; };
|
||
let bk: nkind = btn.kind;
|
||
let sname: str;
|
||
sname.ptr = nil; sname.len = 0;
|
||
if (bk == nkind.N_TPTR) {
|
||
let inner: *node = btn.lhs;
|
||
if (inner != nil) {
|
||
if (inner.kind == nkind.N_TNAME) { sname = inner.str; };
|
||
};
|
||
};
|
||
if (bk == nkind.N_TNAME) { sname = btn.str; };
|
||
if (sname.len == 0) { return nil; };
|
||
let si: *structinfo = structlookup(c, sname);
|
||
if (si == nil) { return nil; };
|
||
let fi: *fieldinfo = si.fields;
|
||
for (fi != nil) {
|
||
if (streq(fi.fname, fld)) { return fi.tnode; };
|
||
fi = fi.finext;
|
||
};
|
||
return nil;
|
||
};
|
||
|
||
// rhstaggedabicall — does `src` produce a tagged value via the AX/DX/CX
|
||
// return ABI? True for N_CALL of a tagged-returning fn, N_INDEX of a
|
||
// tagged-element base, and N_DOT of a tagged-typed struct field (after
|
||
// #28's cgdot fix loads AX/DX/CX/R8 from the field's slot). Used to
|
||
// decide whether cgexpr/spill works for the tagged-source branch of
|
||
// cgwidentaggedstore.
|
||
fn rhstaggedabicall(c: *cgen, src: *node) bool = {
|
||
if (src == nil) { return false; };
|
||
if (src.kind == nkind.N_CALL) {
|
||
let callee: *node = src.lhs;
|
||
if (callee != nil) {
|
||
let calleename: str;
|
||
calleename.ptr = nil; calleename.len = 0;
|
||
if (callee.kind == nkind.N_IDENT) { calleename = callee.str; };
|
||
if (callee.kind == nkind.N_DOT) { calleename = callee.str; };
|
||
if (calleename.len > 0) {
|
||
let rt: *node = fnretlookup(c, calleename);
|
||
if (rt != nil) {
|
||
if (istaggedtype(c, rt)) { return true; };
|
||
};
|
||
};
|
||
};
|
||
return false;
|
||
};
|
||
if (src.kind == nkind.N_INDEX) {
|
||
let base: *node = src.lhs;
|
||
if (base != nil) {
|
||
if (base.kind == nkind.N_IDENT) {
|
||
let bl: *local = localfindnode(c, base.str);
|
||
if (bl != nil) {
|
||
let btn: *node = bl.tnode;
|
||
if (btn != nil) {
|
||
let bk: nkind = btn.kind;
|
||
let elemt: *node = nil;
|
||
if (bk == nkind.N_TARRAY) { elemt = btn.lhs; };
|
||
if (bk == nkind.N_TSLICE) { elemt = btn.lhs; };
|
||
if (bk == nkind.N_TPTR) { elemt = btn.lhs; };
|
||
if (elemt != nil) {
|
||
if (istaggedtype(c, elemt)) {
|
||
return true;
|
||
};
|
||
};
|
||
};
|
||
};
|
||
};
|
||
};
|
||
};
|
||
// N_DOT of a tagged-typed struct field — cgdot loads
|
||
// AX=tag, DX=word0, CX=word1[, R8=word2], so downstream
|
||
// spill matches the call/index shapes.
|
||
if (src.kind == nkind.N_DOT) {
|
||
let ft: *node = dotfieldtnode(c, src);
|
||
if (ft != nil) {
|
||
if (istaggedtype(c, ft)) { return true; };
|
||
};
|
||
};
|
||
return false;
|
||
};
|
||
|
||
// cgloadtaggedfield — load a tagged-union slot at `basereg`+foff
|
||
// into the tagged-return ABI registers (AX=tag, DX=word0, CX=word1,
|
||
// R8=word2). Slot sizes: 16B = (tag, word0), 24B = + word1, 32B
|
||
// = + word2 (slice variant). Mirrors the cstage tagged-field load
|
||
// in cmd/w6c/cgen.c (N_DOT TY_STRUCT/TY_PTR branches).
|
||
//
|
||
// Load order is fixed regardless of basereg: tag, word0, word2,
|
||
// word1. CX (word1 target) goes LAST because basereg may itself
|
||
// be CX — top-level globals address via LEAQ name(SB), CX — and
|
||
// overwriting it earlier would trash the base address for the
|
||
// remaining loads. For BP / BX bases the order is harmless.
|
||
// Callers must guarantee basereg is one of "BP", "BX", "CX"; the
|
||
// only register loaded into that is NOT a target is BX, so AX-
|
||
// or DX-rooted callers must spill first.
|
||
fn cgloadtaggedfield(c: *cgen, basereg: str, foff: i32, slot_sz: i32) void = {
|
||
// tag → AX
|
||
emitline("\tMOVQ\t");
|
||
emitdispreg(foff: i64, basereg);
|
||
emitline(", AX\n");
|
||
// word0 → DX
|
||
emitline("\tMOVQ\t");
|
||
emitdispreg((foff + 8): i64, basereg);
|
||
emitline(", DX\n");
|
||
// word2 → R8 (slice variant: slot = 8 tag + 24 payload = 32).
|
||
if (slot_sz > 24) {
|
||
emitline("\tMOVQ\t");
|
||
emitdispreg((foff + 24): i64, basereg);
|
||
emitline(", R8\n");
|
||
};
|
||
// word1 → CX (load LAST; conflicts with CX-base globals).
|
||
if (slot_sz > 16) {
|
||
emitline("\tMOVQ\t");
|
||
emitdispreg((foff + 16): i64, basereg);
|
||
emitline(", CX\n");
|
||
};
|
||
};
|
||
|
||
// cgwidentaggedstore — write tagged-union slot bytes for `src` into
|
||
// the slot at `basereg`+slot_off, sized to slot_sz. Mirrors
|
||
// cg_widen_tagged_store in cmd/w6c/cgen.c.
|
||
//
|
||
// `basereg` selects the addressing root:
|
||
// - "BP": function-frame slot (let / assign / return / structlit /
|
||
// array-elem scratch). Body writes straight to slot_off(BP).
|
||
// - else (e.g. "BX" for *struct field, top-level struct LEAQ
|
||
// base): pointer-rooted dst. cgexpr inside trashes every GPR,
|
||
// so we route through a fresh BP-rooted scratch slot, spill
|
||
// basereg before the body, reload after, then word-copy
|
||
// scratch → (basereg, slot_off).
|
||
//
|
||
// Branches by source shape:
|
||
// - nullable dst (8B slot): cgexpr → AX → slot+0.
|
||
// - tagged src ident: copy slot words, zero-pad, tag-remap.
|
||
// - tagged src via AX/DX/CX ABI (call / tagged-arr index): cgexpr,
|
||
// spill words; no remap (callee already speaks dst tag order — or
|
||
// it doesn't, in which case the source is the wider one and remap
|
||
// would need a reversed direction we don't currently emit).
|
||
// - struct src (literal or ident): zero slot, write fields at +8+foff,
|
||
// tag last.
|
||
// - str src: tag@+0, ptr@+8, len@+16.
|
||
// - scalar src: tag@+0, value@+8.
|
||
fn cgwidentaggedstore(c: *cgen, dst: *node, src: *node,
|
||
basereg: str, slot_off: i32, slot_sz: i32) void = {
|
||
if (streq(basereg, "BP")) {
|
||
cgwidentaggedstorebp(c, dst, src, slot_off, slot_sz);
|
||
return;
|
||
};
|
||
// Pointer-rooted dst: spill basereg (cgexpr will trash it),
|
||
// materialise into a BP-rooted scratch via the BP path, then
|
||
// reload basereg and word-copy scratch → caller's slot.
|
||
let bspill: i32 = localadd(c, "@tagbase", 8, nil);
|
||
emitline("\tMOVQ\t");
|
||
emitline(basereg);
|
||
emitline(", ");
|
||
emitoff(bspill: i64);
|
||
emitline("(BP)\n");
|
||
let scr: i32 = localadd(c, "@tagscr", slot_sz, nil);
|
||
emitline("\tXORQ\tAX, AX\n");
|
||
let z: i32 = 0;
|
||
for (z < slot_sz) {
|
||
emitline("\tMOVQ\tAX, ");
|
||
emitoff((scr + z): i64);
|
||
emitline("(BP)\n");
|
||
z += 8;
|
||
};
|
||
cgwidentaggedstorebp(c, dst, src, scr, slot_sz);
|
||
emitline("\tMOVQ\t");
|
||
emitoff(bspill: i64);
|
||
emitline("(BP), ");
|
||
emitline(basereg);
|
||
emitline("\n");
|
||
let k: i32 = 0;
|
||
for (k < slot_sz) {
|
||
emitline("\tMOVQ\t");
|
||
emitoff((scr + k): i64);
|
||
emitline("(BP), AX\n");
|
||
emitline("\tMOVQ\tAX, ");
|
||
emitdispreg((slot_off + k): i64, basereg);
|
||
emitline("\n");
|
||
k += 8;
|
||
};
|
||
};
|
||
|
||
// cgwidentaggedstorebp — BP-rooted body. Called via cgwidentaggedstore
|
||
// for the natural "BP" case and via the wrapper's scratch path for
|
||
// pointer-rooted dst. Direct callers exist only in case of future
|
||
// inlined uses inside this file; new code should call the wrapper.
|
||
fn cgwidentaggedstorebp(c: *cgen, dst: *node, src: *node, slot_off: i32, slot_sz: i32) void = {
|
||
let dt: *node = resolvetagged(c, dst);
|
||
if (dt == nil) { return; };
|
||
// Nullable fold: one 8B word holding the pointer (or 0 for void).
|
||
if (isnullabletype(dst)) {
|
||
cgexpr(c, src);
|
||
emitline("\tMOVQ\tAX, ");
|
||
emitoff(slot_off: i64);
|
||
emitline("(BP)\n");
|
||
return;
|
||
};
|
||
// `expr: TaggedAlias` where the cast's destination IS the union
|
||
// itself is a widening, not a re-interpret. cgexpr on a CAST
|
||
// produces the inner's register shape (str: AX=ptr, BX=len), not
|
||
// the tagged AX/DX/CX triple — so peel to the inner and route
|
||
// through the matching concrete-variant branch below. A cast to
|
||
// a concrete variant (`7: i32`) is left intact so the existing
|
||
// scalar / str / slice branches pick the right variant tag.
|
||
if (src != nil) {
|
||
if (src.kind == nkind.N_CAST) {
|
||
if (src.lhs != nil) {
|
||
let inner: *node = src.lhs;
|
||
let inneristagged: bool = false;
|
||
if (inner.kind == nkind.N_IDENT) {
|
||
let lc: *local = localfindnode(c, inner.str);
|
||
if (lc != nil) {
|
||
inneristagged = istaggedtype(c, lc.tnode);
|
||
};
|
||
};
|
||
if (rhstaggedabicall(c, inner)) {
|
||
inneristagged = true;
|
||
};
|
||
// Cast's destination = the dst tagged union
|
||
// itself? The rhs of N_CAST holds the target
|
||
// type. Compare nominally via str match on
|
||
// the tagged-alias name.
|
||
let castisdst: bool = false;
|
||
let castrhs: *node = src.rhs;
|
||
if (castrhs != nil) {
|
||
if (castrhs.kind == nkind.N_TTAGGED) {
|
||
castisdst = true;
|
||
};
|
||
if (castrhs.kind == nkind.N_TNAME) {
|
||
if (dst != nil) {
|
||
if (dst.kind == nkind.N_TNAME) {
|
||
if (streq(castrhs.str, dst.str)) {
|
||
castisdst = true;
|
||
};
|
||
};
|
||
};
|
||
};
|
||
};
|
||
if (castisdst && !inneristagged) {
|
||
src = inner;
|
||
};
|
||
};
|
||
};
|
||
};
|
||
// Tagged source ident: byte-copy slot words then tag-remap.
|
||
let st: *node = rhstaggedident(c, src);
|
||
if (st != nil) {
|
||
let lc: *local = localfindnode(c, src.str);
|
||
let ssz: i32 = slotsize(c, lc.tnode);
|
||
let soff: i32 = lc.off;
|
||
let k: i32 = 0;
|
||
for (k < ssz) {
|
||
emitline("\tMOVQ\t");
|
||
emitoff((soff + k): i64);
|
||
emitline("(BP), AX\n");
|
||
emitline("\tMOVQ\tAX, ");
|
||
emitoff((slot_off + k): i64);
|
||
emitline("(BP)\n");
|
||
k += 8;
|
||
};
|
||
if (ssz < slot_sz) {
|
||
emitline("\tXORQ\tAX, AX\n");
|
||
let p: i32 = ssz;
|
||
for (p < slot_sz) {
|
||
emitline("\tMOVQ\tAX, ");
|
||
emitoff((slot_off + p): i64);
|
||
emitline("(BP)\n");
|
||
p += 8;
|
||
};
|
||
};
|
||
cgwidentagremap(c, dt, st, slot_off);
|
||
return;
|
||
};
|
||
// Tagged source via AX/DX/CX/R8 register ABI (N_CALL, N_INDEX
|
||
// of tagged element). R8 carries the 4th word for slice-payload
|
||
// variants (slot 32B).
|
||
if (rhstaggedabicall(c, src)) {
|
||
cgexpr(c, src);
|
||
emitline("\tMOVQ\tAX, ");
|
||
emitoff(slot_off: i64);
|
||
emitline("(BP)\n");
|
||
if (slot_sz > 8) {
|
||
emitline("\tMOVQ\tDX, ");
|
||
emitoff((slot_off + 8): i64);
|
||
emitline("(BP)\n");
|
||
};
|
||
if (slot_sz > 16) {
|
||
emitline("\tMOVQ\tCX, ");
|
||
emitoff((slot_off + 16): i64);
|
||
emitline("(BP)\n");
|
||
};
|
||
if (slot_sz > 24) {
|
||
emitline("\tMOVQ\tR8, ");
|
||
emitoff((slot_off + 24): i64);
|
||
emitline("(BP)\n");
|
||
};
|
||
return;
|
||
};
|
||
// Struct payload (literal or ident).
|
||
let sname: str = rhsstructpayload(c, src);
|
||
if (sname.len > 0) {
|
||
let si: *structinfo = structlookup(c, sname);
|
||
if (si != nil) {
|
||
emitline("\tXORQ\tAX, AX\n");
|
||
let zoff: i32 = 0;
|
||
for (zoff < slot_sz) {
|
||
emitline("\tMOVQ\tAX, ");
|
||
emitoff((slot_off + zoff): i64);
|
||
emitline("(BP)\n");
|
||
zoff += 8;
|
||
};
|
||
let tag: i32 = taggedvariantindex(c, dt, src);
|
||
if (tag < 0) { tag = 0; };
|
||
if (src.kind == nkind.N_STRUCTLIT) {
|
||
let fnode: *node = src.list;
|
||
for (fnode != nil) {
|
||
if (fnode.kind == nkind.N_FIELD) {
|
||
let fname: str = fnode.str;
|
||
let fi: *fieldinfo = si.fields;
|
||
for (fi != nil) {
|
||
if (streq(fi.fname, fname)) {
|
||
cgexpr(c, fnode.lhs);
|
||
if (isfloattype(c, fi.tnode)) {
|
||
let mov: str = "MOVSD";
|
||
if (isf32type(c, fi.tnode)) {
|
||
mov = "MOVSS";
|
||
};
|
||
emitline("\t");
|
||
emitline(mov);
|
||
emitline("\tX0, ");
|
||
emitoff((slot_off + 8 + fi.foff): i64);
|
||
emitline("(BP)\n");
|
||
} else { if (isstrtype(c, fi.tnode)) {
|
||
emitline("\tMOVQ\tAX, ");
|
||
emitoff((slot_off + 8 + fi.foff): i64);
|
||
emitline("(BP)\n");
|
||
emitline("\tMOVQ\tBX, ");
|
||
emitoff((slot_off + 8 + fi.foff + 8): i64);
|
||
emitline("(BP)\n");
|
||
} else {
|
||
let sop: str = fieldstoreop(c, fi);
|
||
emitline("\t");
|
||
emitline(sop);
|
||
emitline("\tAX, ");
|
||
emitoff((slot_off + 8 + fi.foff): i64);
|
||
emitline("(BP)\n");
|
||
}; };
|
||
fi = nil;
|
||
} else {
|
||
fi = fi.finext;
|
||
};
|
||
};
|
||
};
|
||
fnode = fnode.next;
|
||
};
|
||
} else {
|
||
// Struct ident source: byte-copy struct words to slot+8+k.
|
||
let lc: *local = localfindnode(c, src.str);
|
||
let soff: i32 = 0;
|
||
if (lc != nil) { soff = lc.off; };
|
||
let stotal: i32 = si.totsize;
|
||
let ki: i32 = 0;
|
||
for (ki + 8 <= stotal) {
|
||
emitline("\tMOVQ\t");
|
||
emitoff((soff + ki): i64);
|
||
emitline("(BP), AX\n");
|
||
emitline("\tMOVQ\tAX, ");
|
||
emitoff((slot_off + 8 + ki): i64);
|
||
emitline("(BP)\n");
|
||
ki += 8;
|
||
};
|
||
if (ki < stotal) {
|
||
let tail: i32 = stotal - ki;
|
||
let lop: str = "MOVQ";
|
||
if (tail == 4) { lop = "MOVL"; }
|
||
else { if (tail == 1) { lop = "MOVB"; }; };
|
||
emitline("\t");
|
||
emitline(lop);
|
||
emitline("\t");
|
||
emitoff((soff + ki): i64);
|
||
emitline("(BP), AX\n");
|
||
emitline("\t");
|
||
emitline(lop);
|
||
emitline("\tAX, ");
|
||
emitoff((slot_off + 8 + ki): i64);
|
||
emitline("(BP)\n");
|
||
};
|
||
};
|
||
emitline("\tMOVQ\t$");
|
||
emitint(tag: i64);
|
||
emitline(", ");
|
||
emitoff(slot_off: i64);
|
||
emitline("(BP)\n");
|
||
return;
|
||
};
|
||
};
|
||
// Str payload.
|
||
if (nodeisstr(c, src)) {
|
||
cgexpr(c, src);
|
||
emitline("\tMOVQ\tAX, ");
|
||
emitoff((slot_off + 8): i64);
|
||
emitline("(BP)\n");
|
||
emitline("\tMOVQ\tBX, ");
|
||
emitoff((slot_off + 16): i64);
|
||
emitline("(BP)\n");
|
||
let tag: i32 = taggedvariantindex(c, dt, src);
|
||
if (tag < 0) { tag = 0; };
|
||
emitline("\tMOVQ\t$");
|
||
emitint(tag: i64);
|
||
emitline(", ");
|
||
emitoff(slot_off: i64);
|
||
emitline("(BP)\n");
|
||
return;
|
||
};
|
||
// Slice payload (24B): cgexpr leaves (AX=ptr, BX=len, CX=cap).
|
||
// Slot layout: [+0]=tag, [+8]=ptr, [+16]=len, [+24]=cap.
|
||
if (nodeisslice(c, src)) {
|
||
cgexpr(c, src);
|
||
emitline("\tMOVQ\tAX, ");
|
||
emitoff((slot_off + 8): i64);
|
||
emitline("(BP)\n");
|
||
emitline("\tMOVQ\tBX, ");
|
||
emitoff((slot_off + 16): i64);
|
||
emitline("(BP)\n");
|
||
emitline("\tMOVQ\tCX, ");
|
||
emitoff((slot_off + 24): i64);
|
||
emitline("(BP)\n");
|
||
let tag: i32 = taggedvariantindex(c, dt, src);
|
||
if (tag < 0) { tag = 0; };
|
||
emitline("\tMOVQ\t$");
|
||
emitint(tag: i64);
|
||
emitline(", ");
|
||
emitoff(slot_off: i64);
|
||
emitline("(BP)\n");
|
||
return;
|
||
};
|
||
// Scalar payload.
|
||
cgexpr(c, src);
|
||
emitline("\tMOVQ\tAX, ");
|
||
emitoff((slot_off + 8): i64);
|
||
emitline("(BP)\n");
|
||
let tag: i32 = taggedvariantindex(c, dt, src);
|
||
if (tag < 0) { tag = 0; };
|
||
emitline("\tMOVQ\t$");
|
||
emitint(tag: i64);
|
||
emitline(", ");
|
||
emitoff(slot_off: i64);
|
||
emitline("(BP)\n");
|
||
return;
|
||
};
|
||
|
||
// Spine-walk a chained N_DOT (n) inward to a root ident, summing field
|
||
// offsets through value-struct intermediates. Optional slice/str leaf
|
||
// pseudo-field (.ptr / .len / .cap) on the last segment is folded into
|
||
// *outslicedelta (0/8/16); otherwise *outleaffi is the leaf fieldinfo
|
||
// and *outslicedelta stays -1. Returns true on success; on false the
|
||
// caller falls through to other branches.
|
||
//
|
||
// Mirrors cmd/w6c/cgen.c's N_DOT chained walker; both stages must agree
|
||
// on the same shapes so the bootstrap fixed-point holds. The chain
|
||
// depth is capped at 16 — deeper chains are vanishingly rare and fall
|
||
// through.
|
||
//
|
||
// On success the caller emits one load/store at root_base + *outtotaloff
|
||
// (+ slicedelta for pseudo leaf). Root resolves as: local frame slot
|
||
// (*outisglobal false, base = *outrootoff(BP)) or top-level let
|
||
// (*outisglobal true, base reached via LEAQ *outrootname(SB), CX).
|
||
//
|
||
// Numeric out-params are i32 — offsets fit naturally and the post-#19
|
||
// localloadop sign-extends i32 deref-stored slots on read, so negative
|
||
// frame offsets round-trip intact.
|
||
export fn dotchainresolve(c: *cgen, n: *node,
|
||
outrootname: *str, outrootoff: *i32, outtotaloff: *i32,
|
||
outleaffi: **fieldinfo, outslicedelta: *i32,
|
||
outisglobal: *bool, outptrroot: *bool) bool = {
|
||
*outrootname = "";
|
||
*outrootoff = 0;
|
||
*outisglobal = false;
|
||
*outptrroot = false;
|
||
*outtotaloff = 0;
|
||
*outleaffi = nil;
|
||
*outslicedelta = -1;
|
||
if (n == nil) { return false; };
|
||
if (n.kind != nkind.N_DOT) { return false; };
|
||
let stk: [16]*node;
|
||
let nsteps: i32 = 0;
|
||
let cur: *node = n;
|
||
for (cur != nil) {
|
||
if (cur.kind != nkind.N_DOT) { break; };
|
||
if (nsteps >= 16) { return false; };
|
||
stk[nsteps] = cur;
|
||
nsteps += 1;
|
||
cur = cur.lhs;
|
||
};
|
||
if (nsteps < 2) { return false; };
|
||
if (cur == nil) { return false; };
|
||
if (cur.kind != nkind.N_IDENT) { return false; };
|
||
*outrootname = cur.str;
|
||
let rootstruct: str = "";
|
||
let lc: *local = localfindnode(c, cur.str);
|
||
if (lc != nil) {
|
||
if (lc.tnode != nil) {
|
||
if (lc.tnode.kind == nkind.N_TNAME) {
|
||
rootstruct = lc.tnode.str;
|
||
*outrootoff = lc.off;
|
||
};
|
||
// `*T` root (param/local): dereference at emit time;
|
||
// pointee struct supplies the field layout. Callers
|
||
// that opt in via *outptrroot emit a MOVQ load of the
|
||
// slot before indexing.
|
||
if (lc.tnode.kind == nkind.N_TPTR) {
|
||
let pe: *node = lc.tnode.lhs;
|
||
if (pe != nil) {
|
||
if (pe.kind == nkind.N_TNAME) {
|
||
rootstruct = pe.str;
|
||
*outrootoff = lc.off;
|
||
*outptrroot = true;
|
||
};
|
||
};
|
||
};
|
||
};
|
||
};
|
||
if (rootstruct.len == 0) {
|
||
let gsi: *structinfo = letvarstructinfo(c, cur.str);
|
||
if (gsi != nil) {
|
||
rootstruct = gsi.sname;
|
||
*outisglobal = true;
|
||
};
|
||
};
|
||
if (rootstruct.len == 0) { return false; };
|
||
let curstruct: str = rootstruct;
|
||
let i: i32 = nsteps - 1;
|
||
for (i >= 0) {
|
||
let csi: *structinfo = structlookup(c, curstruct);
|
||
if (csi == nil) { return false; };
|
||
if (stk[i] == nil) { return false; };
|
||
let stepnm: str = stk[i].str;
|
||
let fi: *fieldinfo = csi.fields;
|
||
let found: *fieldinfo = nil;
|
||
for (fi != nil) {
|
||
if (streq(fi.fname, stepnm)) { found = fi; break; };
|
||
fi = fi.finext;
|
||
};
|
||
if (found == nil) { return false; };
|
||
if (i == 0) {
|
||
*outtotaloff = *outtotaloff + found.foff;
|
||
*outleaffi = found;
|
||
return true;
|
||
};
|
||
let ft: *node = found.tnode;
|
||
if (ft == nil) { return false; };
|
||
if (ft.kind == nkind.N_TNAME) {
|
||
if (streq(ft.str, "str")) {
|
||
if (i != 1) { return false; };
|
||
let pseudo: str = stk[0].str;
|
||
let delta: i32 = -1;
|
||
if (streq(pseudo, "ptr")) { delta = 0; }
|
||
else { if (streq(pseudo, "len")) { delta = 8; }; };
|
||
if (delta < 0) { return false; };
|
||
*outtotaloff = *outtotaloff + found.foff;
|
||
*outslicedelta = delta;
|
||
return true;
|
||
};
|
||
if (primsize(ft.str) != 0) { return false; };
|
||
*outtotaloff = *outtotaloff + found.foff;
|
||
curstruct = ft.str;
|
||
i -= 1;
|
||
} else { if (ft.kind == nkind.N_TSLICE) {
|
||
if (i != 1) { return false; };
|
||
let pseudo: str = stk[0].str;
|
||
let delta: i32 = -1;
|
||
if (streq(pseudo, "ptr")) { delta = 0; }
|
||
else { if (streq(pseudo, "len")) { delta = 8; }
|
||
else { if (streq(pseudo, "cap")) { delta = 16; }; }; };
|
||
if (delta < 0) { return false; };
|
||
*outtotaloff = *outtotaloff + found.foff;
|
||
*outslicedelta = delta;
|
||
return true;
|
||
} else {
|
||
return false;
|
||
}; };
|
||
};
|
||
return false;
|
||
};
|