wcc/ww: exprtypeoftry prefers the current module's symbol

The try-operand resolution used bare lookups (ident + bare-leaf call);
a cross-module same-leaf collision mistyped the operand. Prefer the
current module. The historic 995 byte-id break attributed to this swap
was contamination from the guard-bug-carrying bundle — re-probed clean
in isolation and at the full stack. The N_DOT module-keyed leaf stays
task #51. Report item [11], lookup half.

Makefile

@@ -261,6 +261,7 @@ TESTS	= $(BIN)/test_smoke $(BIN)/test_lex $(BIN)/test_parse $(BIN)/test_check \
 	  $(BIN)/test_defdim_argslice_run \
 	  $(BIN)/test_slttypepref_run \
 	  $(BIN)/test_ampfncollide_run \
+	  $(BIN)/test_trycallcollide_run \
 	  $(BIN)/test_gunsigned_run \
 	  $(BIN)/test_taggedidx_run \
 	  $(BIN)/test_fnptrcollide_run \
@@ -804,6 +805,17 @@ $(BIN)/test_ampfncollide_run: test/wcc/989_ampfncollide_run.c \
 		$(LIB)/libwwrt.a | $(BIN)
 	$(CC) $(CFLAGS) -o $@ $<
 
+# 989_trycallcollide_run (#11a, c3): exprtypeoftry prefers the current
+# module's symbol when typing a `?`/`!` operand whose bare leaf collides with
+# a same-leaf decl in a later module. Builds+runs on BOTH driver twins
+# (rule-10). See the test header.
+$(BIN)/test_trycallcollide_run: test/wcc/989_trycallcollide_run.c \
+		$(BIN)/ww $(BIN)/ww_ww \
+		$(BIN)/w6c $(BIN)/w6a $(BIN)/w6l \
+		$(BIN)/w6c_ww $(BIN)/w6a_ww $(BIN)/w6l_ww \
+		$(LIB)/libwwrt.a | $(BIN)
+	$(CC) $(CFLAGS) -o $@ $<
+
 # 989_gunsigned_run (F7-c5, #25): a module-global unsigned ident on the
 # divide/shift/relational path must pick the unsigned opcode. Builds+runs on
 # BOTH driver twins (rule-10). CLASS-M — see the test header.

selfhost/cmd/w6c/main.combined.ww

@@ -16307,14 +16307,13 @@ fn checkisas(c: *checker, n: *node) void = {
 fn exprtypeoftry(c: *checker, e: *node) *node = {
 	if (e == nil) { return nil; };
 	if (e.kind == nkind.N_IDENT) {
-		// #11a/task #50: this bare-leaf lookup wants curmod preference
+		// #11a: curmod preference (the #53/#55 family). A bare ident
-		// (scopelookupprefer, the #53/#55 family) but the swap BROKE the
+		// whose leaf also names a global in a later module otherwise
-		// 995 self-rebuild byte-id — in the bundled self-compile ww's
+		// binds the foreign decl's type, mis-typing the try operand and
-		// scopelookupprefer diverges from cstage's resolution (the same
+		// either spuriously rejecting valid `?` code or skipping the F8
-		// curmod-in-bundle layer that blocked #5), flipping a try-operand
+		// reject. Mirrors exprtype's own N_IDENT arm (scopelookupprefer
-		// stamp in the selfhost source. Held at plain scopelookup until #50
+		// at :2897); cstage types the operand via cexpr with cur_mod.
-		// lands the bundle curmod fix; aligning here in isolation is unsound.
+		let s: *sym = scopelookupprefer(c.cur, c.curmod, e.str);
-		let s: *sym = scopelookup(c.cur, e.str);
 		if (s == nil) { return nil; };
 		if (s.decl == nil) { return nil; };
 		return s.decl.lhs;
@@ -16335,10 +16334,14 @@ fn exprtypeoftry(c: *checker, e: *node) *node = {
 		// returns nil below) rides task #51 with the fn-ptr-callee desugar.
 		if (callee.kind == nkind.N_DOT)   { nm = callee.str; };
 		if (nm.len == 0) { return nil; };
-		// #11a/task #50: curmod preference wanted here too, held at plain
+		// #11a: curmod preference for the bare-leaf callee. A same-leaf
-		// scopelookup — the prefer swap broke 995 byte-id (bundle curmod
+		// `op()?` declared in a later module otherwise binds the foreign
-		// divergence, same as the N_IDENT arm above + #5/#50).
+		// op's return type — its error subset then spuriously fails (or
-		let s: *sym = scopelookup(c.cur, nm);
+		// wrongly passes) the enclosing-return check. Mirrors exprtype's
+		// N_CALL arm (scopelookupprefer at :3336). The N_DOT-callee leaf
+		// (callee.str above) still resolves bare-leaf, not via the module
+		// qualifier callee.lhs.str — that module-keyed fix rides task #51.
+		let s: *sym = scopelookupprefer(c.cur, c.curmod, nm);
 		if (s == nil) { return nil; };
 		if (s.skind != skind.SK_FN) { return nil; };
 		if (s.decl == nil) { return nil; };

selfhost/cmd/wcc/check.ww

@@ -5867,14 +5867,13 @@ fn checkisas(c: *checker, n: *node) void = {
 fn exprtypeoftry(c: *checker, e: *node) *node = {
 	if (e == nil) { return nil; };
 	if (e.kind == nkind.N_IDENT) {
-		// #11a/task #50: this bare-leaf lookup wants curmod preference
+		// #11a: curmod preference (the #53/#55 family). A bare ident
-		// (scopelookupprefer, the #53/#55 family) but the swap BROKE the
+		// whose leaf also names a global in a later module otherwise
-		// 995 self-rebuild byte-id — in the bundled self-compile ww's
+		// binds the foreign decl's type, mis-typing the try operand and
-		// scopelookupprefer diverges from cstage's resolution (the same
+		// either spuriously rejecting valid `?` code or skipping the F8
-		// curmod-in-bundle layer that blocked #5), flipping a try-operand
+		// reject. Mirrors exprtype's own N_IDENT arm (scopelookupprefer
-		// stamp in the selfhost source. Held at plain scopelookup until #50
+		// at :2897); cstage types the operand via cexpr with cur_mod.
-		// lands the bundle curmod fix; aligning here in isolation is unsound.
+		let s: *sym = scopelookupprefer(c.cur, c.curmod, e.str);
-		let s: *sym = scopelookup(c.cur, e.str);
 		if (s == nil) { return nil; };
 		if (s.decl == nil) { return nil; };
 		return s.decl.lhs;
@@ -5895,10 +5894,14 @@ fn exprtypeoftry(c: *checker, e: *node) *node = {
 		// returns nil below) rides task #51 with the fn-ptr-callee desugar.
 		if (callee.kind == nkind.N_DOT)   { nm = callee.str; };
 		if (nm.len == 0) { return nil; };
-		// #11a/task #50: curmod preference wanted here too, held at plain
+		// #11a: curmod preference for the bare-leaf callee. A same-leaf
-		// scopelookup — the prefer swap broke 995 byte-id (bundle curmod
+		// `op()?` declared in a later module otherwise binds the foreign
-		// divergence, same as the N_IDENT arm above + #5/#50).
+		// op's return type — its error subset then spuriously fails (or
-		let s: *sym = scopelookup(c.cur, nm);
+		// wrongly passes) the enclosing-return check. Mirrors exprtype's
+		// N_CALL arm (scopelookupprefer at :3336). The N_DOT-callee leaf
+		// (callee.str above) still resolves bare-leaf, not via the module
+		// qualifier callee.lhs.str — that module-keyed fix rides task #51.
+		let s: *sym = scopelookupprefer(c.cur, c.curmod, nm);
 		if (s == nil) { return nil; };
 		if (s.skind != skind.SK_FN) { return nil; };
 		if (s.decl == nil) { return nil; };

selfhost/cmd/wwdump/main.combined.ww

@@ -16307,14 +16307,13 @@ fn checkisas(c: *checker, n: *node) void = {
 fn exprtypeoftry(c: *checker, e: *node) *node = {
 	if (e == nil) { return nil; };
 	if (e.kind == nkind.N_IDENT) {
-		// #11a/task #50: this bare-leaf lookup wants curmod preference
+		// #11a: curmod preference (the #53/#55 family). A bare ident
-		// (scopelookupprefer, the #53/#55 family) but the swap BROKE the
+		// whose leaf also names a global in a later module otherwise
-		// 995 self-rebuild byte-id — in the bundled self-compile ww's
+		// binds the foreign decl's type, mis-typing the try operand and
-		// scopelookupprefer diverges from cstage's resolution (the same
+		// either spuriously rejecting valid `?` code or skipping the F8
-		// curmod-in-bundle layer that blocked #5), flipping a try-operand
+		// reject. Mirrors exprtype's own N_IDENT arm (scopelookupprefer
-		// stamp in the selfhost source. Held at plain scopelookup until #50
+		// at :2897); cstage types the operand via cexpr with cur_mod.
-		// lands the bundle curmod fix; aligning here in isolation is unsound.
+		let s: *sym = scopelookupprefer(c.cur, c.curmod, e.str);
-		let s: *sym = scopelookup(c.cur, e.str);
 		if (s == nil) { return nil; };
 		if (s.decl == nil) { return nil; };
 		return s.decl.lhs;
@@ -16335,10 +16334,14 @@ fn exprtypeoftry(c: *checker, e: *node) *node = {
 		// returns nil below) rides task #51 with the fn-ptr-callee desugar.
 		if (callee.kind == nkind.N_DOT)   { nm = callee.str; };
 		if (nm.len == 0) { return nil; };
-		// #11a/task #50: curmod preference wanted here too, held at plain
+		// #11a: curmod preference for the bare-leaf callee. A same-leaf
-		// scopelookup — the prefer swap broke 995 byte-id (bundle curmod
+		// `op()?` declared in a later module otherwise binds the foreign
-		// divergence, same as the N_IDENT arm above + #5/#50).
+		// op's return type — its error subset then spuriously fails (or
-		let s: *sym = scopelookup(c.cur, nm);
+		// wrongly passes) the enclosing-return check. Mirrors exprtype's
+		// N_CALL arm (scopelookupprefer at :3336). The N_DOT-callee leaf
+		// (callee.str above) still resolves bare-leaf, not via the module
+		// qualifier callee.lhs.str — that module-keyed fix rides task #51.
+		let s: *sym = scopelookupprefer(c.cur, c.curmod, nm);
 		if (s == nil) { return nil; };
 		if (s.skind != skind.SK_FN) { return nil; };
 		if (s.decl == nil) { return nil; };

test/wcc/989_trycallcollide_run.c

@@ -0,0 +1,180 @@
+/*
+ * 989_trycallcollide_run (#11a, c3) — exprtypeoftry must prefer the current
+ * module's symbol when typing a `?`/`!` operand whose bare leaf collides with
+ * a same-leaf decl in a later module.
+ *
+ * THE BUG (review item #11, 2026-06-11): exprtypeoftry (check.ww ~5850 N_IDENT,
+ * ~5874 N_CALL bare-leaf callee) typed the try operand with bare scopelookup —
+ * no (name,module) preference. scopedefineinmodule PREPENDS, so a later
+ * module's same-leaf decl heads the chain and the operand is typed against ITS
+ * signature. For `op()?` the wrong op's error subset is then checked against
+ * the enclosing fn's return: a spurious "?: error variant not in enclosing
+ * return" rejects valid code (or, with a narrower foreign subset, silently
+ * skips the F8 multi-success reject). cstage types the operand via cexpr with
+ * cur_mod. THE FIX: both arms use scopelookupprefer(c.cur, c.curmod, ...),
+ * mirroring exprtype's own N_IDENT/N_CALL arms (:2897/:3336).
+ *
+ * GATING NOTE: this swap broke 995_self_rebuild once in a CONTAMINATED earlier
+ * attempt (bundled with a u64-guard-buggy scopelookuptype). Re-probed clean
+ * atop c1 (i32-correct scopelookuptype): repro closes AND 990-997/995 green.
+ *
+ *   row        | shape                                       | run (cs==ww)
+ *   -----------+---------------------------------------------+-------------
+ *   callcollide| beta.user() does `op()?`; gamma also has    | 42 (was ww
+ *              |  `op` with a wider error subset             |  build-fail)
+ *   noclash    | same, gamma.op renamed (no collision)       | 42 (control)
+ *
+ * The N_DOT-callee module-keyed resolution stays task #51 (out of scope).
+ * Single-file multi-package source is the sanctioned shape (cmd/ww/main.c).
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+
+static int
+runwait(const char *cmd)
+{
+	int rc = system(cmd);
+	if (rc == -1) return -1;
+	if (WIFEXITED(rc)) return WEXITSTATUS(rc);
+	return -1;
+}
+
+struct row { const char *label; const char *src; int want; };
+
+static const struct row rows[] = {
+	{ "callcollide",
+	  "package beta;\n"
+	  "export type berr = !void;\n"
+	  "export fn op() (i32 | berr) = { return 5; };\n"
+	  "export fn user() (i32 | berr) = {\n"
+	  "	let v: i32 = op()?;\n"
+	  "	return v + 37;\n"
+	  "};\n"
+	  "package gamma;\n"
+	  "export type gerr1 = !void;\n"
+	  "export type gerr2 = !u8;\n"
+	  "export fn op() (i32 | gerr1 | gerr2) = { return 0; };\n"
+	  "package main;\n"
+	  "import beta;\n"
+	  "import gamma;\n"
+	  "fn main() int = {\n"
+	  "	match (beta.user()) {\n"
+	  "	case let n: i32 => return n: int;\n"
+	  "	case berr => return 99;\n"
+	  "	};\n"
+	  "};\n",
+	  42 },
+
+	{ "noclash",
+	  "package beta;\n"
+	  "export type berr = !void;\n"
+	  "export fn op() (i32 | berr) = { return 5; };\n"
+	  "export fn user() (i32 | berr) = {\n"
+	  "	let v: i32 = op()?;\n"
+	  "	return v + 37;\n"
+	  "};\n"
+	  "package gamma;\n"
+	  "export type gerr1 = !void;\n"
+	  "export fn other() (i32 | gerr1) = { return 0; };\n"
+	  "package main;\n"
+	  "import beta;\n"
+	  "import gamma;\n"
+	  "fn main() int = {\n"
+	  "	match (beta.user()) {\n"
+	  "	case let n: i32 => return n: int;\n"
+	  "	case berr => return 99;\n"
+	  "	};\n"
+	  "};\n",
+	  42 },
+};
+
+static int
+run_build(const char *driver, const struct row *r, int i)
+{
+	char src[64], tmpdir[64], cmd[1024];
+	snprintf(src, sizeof src, "/tmp/tcc_%d_%d.ww", getpid(), i);
+	snprintf(tmpdir, sizeof tmpdir, "/tmp/tcc_%d_d_%d", getpid(), i);
+
+	FILE *f = fopen(src, "wb");
+	if (!f) return -2;
+	fputs(r->src, f);
+	fclose(f);
+
+	mkdir(tmpdir, 0755);
+	snprintf(cmd, sizeof cmd, "cd %s && %s build %s 2>/dev/null",
+	    tmpdir, driver, src);
+	int brc = runwait(cmd);
+
+	const char *base = strrchr(src, '/');
+	base = base ? base + 1 : src;
+	char outbin[128];
+	snprintf(outbin, sizeof outbin, "%s/%s", tmpdir, base);
+	char *dot = strrchr(outbin, '.');
+	if (dot && strcmp(dot, ".ww") == 0) *dot = '\0';
+
+	int got = -1;
+	if (brc == 0) got = runwait(outbin);
+
+	unlink(src); unlink(outbin); rmdir(tmpdir);
+	return brc == 0 ? got : -1;	/* -1 == build failed */
+}
+
+int
+main(void)
+{
+	const char *bin = getenv("BIN");
+	if (!bin) bin = "out/bin";
+	char absbin[1024];
+	if (bin[0] != '/') {
+		char cwd[1024];
+		if (getcwd(cwd, sizeof cwd) == NULL) return 1;
+		snprintf(absbin, sizeof absbin, "%s/%s", cwd, bin);
+		bin = absbin;
+	}
+
+	char cdrv[1024], wdrv[1024];
+	snprintf(cdrv, sizeof cdrv, "%s/ww", bin);
+	snprintf(wdrv, sizeof wdrv, "%s/ww_ww", bin);
+	int have_ww = (access(wdrv, X_OK) == 0);
+
+	int n = (int)(sizeof rows / sizeof rows[0]);
+	int total = 0, fail = 0;
+
+	for (int i = 0; i < n; i++) {
+		total++;
+		int gc = run_build(cdrv, &rows[i], i);
+		if (gc != rows[i].want) {
+			fprintf(stderr, "trycallcollide[cstage][%s]: got=%d want=%d\n",
+			    rows[i].label, gc, rows[i].want);
+			fail++;
+		}
+		if (!have_ww) {
+			fprintf(stderr, "trycallcollide: skip wwstage (no %s)\n", wdrv);
+			continue;
+		}
+		int gw = run_build(wdrv, &rows[i], i);
+		if (gw != gc) {
+			fprintf(stderr, "trycallcollide[%s]: cs=%d != ww=%d "
+			    "(exprtypeoftry cross-module try-operand misbind — #11a c3)\n",
+			    rows[i].label, gc, gw);
+			fail++;
+		}
+		if (gw != rows[i].want) {
+			fprintf(stderr, "trycallcollide[wwstage][%s]: got=%d want=%d\n",
+			    rows[i].label, gw, rows[i].want);
+			fail++;
+		}
+	}
+
+	if (fail) {
+		fprintf(stderr, "trycallcollide_run: %d/%d checks failed\n",
+		    fail, total);
+		return 1;
+	}
+	printf("trycallcollide_run: %d/%d ok\n", total, total);
+	return 0;
+}