build: close package variant identity gaps

cmd/wcc/check.c

@@ -3060,7 +3060,9 @@ lookup_visible_type(Checker *c, const char *name)
 	for (Scope *p = c->cur; p; p = p->parent) {
 		for (Sym *b = p->first; b; b = b->next)
 			if (b->kind == SK_TYPE && strcmp(b->name, name) == 0
-			    && direct_module_visible(c, b->mod))
+			    && direct_module_visible(c, b->mod)
+			    && (b->decl == NULL || !b->decl->imported
+				|| b->decl->export))
 				return b;
 	}
 	return NULL;

cmd/ww/main.c

@@ -1182,6 +1182,13 @@ sep_add_generated_main(struct sepgraph *g, struct sepproduct *product,
 		fprintf(stderr, "ww: generated test-main identity is too long\n");
 		return -1;
 	}
+	for (int i = 0; i < g->n; i++) {
+		if (strcmp(g->pkg[i].path, p->path) != 0) continue;
+		fprintf(stderr,
+		    "ww: generated test-main package identity collides with source import %s\n",
+		    p->path);
+		return -1;
+	}
 	snprintf(p->entry, sizeof p->entry, "%s", variantentry);
 	snprintf(p->name, sizeof p->name, "main");
 	p->variant = SEP_VARIANT_TEST_MAIN;
@@ -1361,6 +1368,21 @@ sep_topo_visit(struct sepgraph *g, int pi, int *order, int *no,
  * with an unrelated normal action in the command-global universe, but never
  * in one product. A single link closure must remain an unambiguous package
  * namespace. */
+static int
+sep_internal_replaces_production(const struct sepgraph *g, int a, int b)
+{
+	const struct seppkg *internal = &g->pkg[a];
+	const struct seppkg *production = &g->pkg[b];
+	if (internal->variant != SEP_VARIANT_SAME_TEST) {
+		internal = &g->pkg[b];
+		production = &g->pkg[a];
+	}
+	return internal->variant == SEP_VARIANT_SAME_TEST
+	    && production->variant == SEP_VARIANT_PRODUCTION
+	    && production->role != SEP_ROLE_TEST_SUPPORT
+	    && strcmp(internal->canon, production->canon) == 0;
+}
+
 static int
 sep_validate_module_closure(struct sepgraph *g, const int *order, int n,
     int include_root)
@@ -1372,7 +1394,8 @@ sep_validate_module_closure(struct sepgraph *g, const int *order, int n,
 		for (int j = i + 1; j < n; j++) {
 			int b = order[j];
 			if (!include_root && g->pkg[b].root) continue;
-			if (strcmp(g->pkg[a].path, g->pkg[b].path) == 0) {
+			if (strcmp(g->pkg[a].path, g->pkg[b].path) == 0
+			    && !sep_internal_replaces_production(g, a, b)) {
 				fprintf(stderr,
 				    "ww: product closure contains multiple packages named %s\n",
 				    g->pkg[a].path);

selfhost/cmd/wcc/check.ww

@@ -312,7 +312,9 @@ fn lookupvisibletype(c: *checker, name: str) *syntax.sym = {
 		for (b != nil) {
 			if (b.skind == syntax.skind.SK_TYPE
 			    && syntax.streq(b.name, name)
-			    && directmodvisible(c, b.mod)) { return b; };
+			    && directmodvisible(c, b.mod)
+			    && (b.decl == nil || b.decl.imported == 0
+				|| b.decl.exported != 0)) { return b; };
 			b = b.snext;
 		};
 		p = p.parent;

selfhost/cmd/ww/main.ww

@@ -1397,6 +1397,15 @@ fn sepaddgeneratedmain(g: *sepgraph, product: *sepproduct, ordinal: i32,
 	if (variant < 0 || variant >= g.n) { return -1; };
 	let p: *seppkg = &g.pkg[g.n];
 	p.path = generatedmainpath(ordinal);
+	let pathi: i32 = 0;
+	for (pathi < g.n) {
+		if (cstreq(g.pkg[pathi].path, p.path)) {
+			cerr("ww: generated test-main package identity collides with source import ");
+			cerr(pathstr(p.path)); cerr("\n");
+			return -1;
+		};
+		pathi += 1;
+	};
 	p.entry = g.pkg[variant].entry;
 	p.artifact = productartifact(ordinal, SEP_VARIANT_TEST_MAIN);
 	p.name = arenadupcstr("main\0".ptr, 4u64);
@@ -1613,6 +1622,20 @@ fn septopovisit(g: *sepgraph, pi: i32, order: []i32, no: *i32,
 	return 0;
 };
 
+fn sepinternalreplacesproduction(g: *sepgraph, a: i32, b: i32) bool = {
+	let internal: i32 = a;
+	let production: i32 = b;
+	if (g.pkg[internal].variant != SEP_VARIANT_SAME_TEST) {
+		internal = b;
+		production = a;
+	};
+	return g.pkg[internal].variant == SEP_VARIANT_SAME_TEST
+		&& g.pkg[production].variant == SEP_VARIANT_PRODUCTION
+		&& g.pkg[production].role != SEP_ROLE_TEST_SUPPORT
+		&& os.samefile(pathstr(g.pkg[internal].entry),
+			pathstr(g.pkg[production].entry));
+};
+
 fn sepvalidatemoduleclosure(g: *sepgraph, order: []i32, n: i32,
     includeroot: bool) i32 = {
 	let i: i32 = 0;
@@ -1624,7 +1647,8 @@ fn sepvalidatemoduleclosure(g: *sepgraph, order: []i32, n: i32,
 			for (j < n) {
 				let b: i32 = order[j];
 				if ((includeroot || !g.pkg[b].root)
-				    && cstreq(g.pkg[a].path, g.pkg[b].path)) {
+				    && cstreq(g.pkg[a].path, g.pkg[b].path)
+				    && !sepinternalreplacesproduction(g, a, b)) {
 					cerr("ww: product closure contains multiple packages named ");
 					cerr(pathstr(g.pkg[a].path)); cerr("\n");
 					return -1;

test/byteid/wwi_test.ww

@@ -302,7 +302,7 @@ fn m2positive(pkg: str) void = {
 	};
 	testenv.writefile(strings.concat(td, "/consumer.ww"), strings.concat(
 		"package consumer;\nimport leaktest;\n",
-		"fn forbidden(s: leaktest.secret) void = {};\n"));
+		"fn forbidden(s: secret) void = {};\n"));
 	let ccav: []str = [testenv.driver("w6c"), "-c", "--import",
 		"leaktest", "cs.wwi", "-o", "cs.s", "consumer.ww"];
 	let wcav: []str = [testenv.driver("w6c_ww"), "-c", "--import",
@@ -314,8 +314,7 @@ fn m2positive(pkg: str) void = {
 	if (cco.termination != exec.termination.EXIT || cco.code == 0
 	    || wco.termination != exec.termination.EXIT || wco.code == 0
 	    || !testenv.same(cco.stderr, wco.stderr)
-	    || !testenv.has(cco.stderr,
+	    || !testenv.has(cco.stderr, "unknown type 'secret'")) {
-		"package 'leaktest' has no exported declaration 'secret'")) {
 		fail("private-closure", "private nominal became source-visible");
 	};
 	testenv.clean(td);