package localbuild_test;

// End-to-end local package builds through both production drivers. Fixtures
// are created at runtime so there is no manifest or hidden graph input: every
// edge below comes from an ordinary WW import declaration.

import os;
import os.exec;
import strings;
import testenv;
import time;

fn fail(label: str, why: str) void = {
	let m: str = strings.concat("localbuild FAIL: ", label, " -- ", why,
		"\n");
	os.write(2, m.ptr, m.len: u64);
	assert(false);
};

fn tmo() time.duration = {
	return (240i64 * (time.second: i64)): time.duration;
};

fn mkdir(path: str) void = { assert(os.mkdir(path, 493) == 0); };

fn command(dir: str, name: str, argv: []str,
	out: *testenv.commandout) void = {
	testenv.runcommand(dir, dir, name, argv, tmo(), out);
};

fn code(dir: str, name: str, argv: []str) i32 = {
	let co: testenv.commandout;
	command(dir, name, argv, &co);
	if (co.termination != exec.termination.EXIT) { return -1; };
	return co.code;
};

fn build(dir: str, driver: str, tag: str, target: str, out: str) i32 = {
	let av: []str = [testenv.driver(driver), "build", "-I", dir,
		"-o", out, target];
	return code(dir, strings.concat("build_", tag), av);
};

fn roottraceenv(source: str, runtime: str,
	compiler: str, assembler: str, linker: str,
	compilertrace: str, assemblertrace: str, linkertrace: str,
	realcompiler: str, realassembler: str, reallinker: str) []str = {
	let base: []str = os.getenvs();
	let env: []str = alloc([], (base.len + 11): u64)!;
	let i: i32 = 0;
	for (i < base.len) {
		if (!strings.hasprefix(base[i], "WW_SRCLIB=")
		    && !strings.hasprefix(base[i], "WW_LIB=")
		    && !strings.hasprefix(base[i], "WW_W6C=")
		    && !strings.hasprefix(base[i], "WW_W6A=")
		    && !strings.hasprefix(base[i], "WW_W6L=")
		    && !strings.hasprefix(base[i], "WW_ROOT_COMPILER_TRACE=")
		    && !strings.hasprefix(base[i], "WW_ROOT_ASSEMBLER_TRACE=")
		    && !strings.hasprefix(base[i], "WW_ROOT_LINKER_TRACE=")
		    && !strings.hasprefix(base[i], "WW_ROOT_REAL_COMPILER=")
		    && !strings.hasprefix(base[i], "WW_ROOT_REAL_ASSEMBLER=")
		    && !strings.hasprefix(base[i], "WW_ROOT_REAL_LINKER=")) {
			append(env, base[i]);
		};
		i += 1;
	};
	append(env, strings.concat("WW_SRCLIB=", source));
	append(env, strings.concat("WW_LIB=", runtime));
	append(env, strings.concat("WW_W6C=", compiler));
	append(env, strings.concat("WW_W6A=", assembler));
	append(env, strings.concat("WW_W6L=", linker));
	append(env, strings.concat("WW_ROOT_COMPILER_TRACE=", compilertrace));
	append(env, strings.concat("WW_ROOT_ASSEMBLER_TRACE=", assemblertrace));
	append(env, strings.concat("WW_ROOT_LINKER_TRACE=", linkertrace));
	append(env, strings.concat("WW_ROOT_REAL_COMPILER=", realcompiler));
	append(env, strings.concat("WW_ROOT_REAL_ASSEMBLER=", realassembler));
	append(env, strings.concat("WW_ROOT_REAL_LINKER=", reallinker));
	return env;
};

fn diagnosticbody(s: str) str = {
	let p: i32 = testenv.pos(s, ": error: ");
	// Driver-owned graph diagnostics have no source-location prefix. Compare
	// those in full; strip only compiler paths/locations from source errors.
	if (p < 0) { return s; };
	let begin: i32 = p + 9;
	let end: i32 = begin;
	for (end < s.len && s[end] != '\n') { end += 1; };
	return strings.sub(s, begin, end);
};

fn rejectstable(dir: str, label: str, target: str, needle: str) void = {
	let drivers: []str = ["ww", "ww_ww", "ww", "ww_ww"];
	let tags: []str = ["c1", "w1", "c2", "w2"];
	let errors: []str = ["", "", "", ""];
	let cwork: str = strings.concat(dir, "/work-", label, "-c");
	let wwork: str = strings.concat(dir, "/work-", label, "-w");
	mkdir(cwork); mkdir(wwork);
	let i: i32 = 0;
	for (i < drivers.len) {
		let out: str = strings.concat(dir, "/reject-", label, "-", tags[i]);
		let work: str = cwork;
		if (i == 1 || i == 3) { work = wwork; };
		let av: []str = [testenv.driver(drivers[i]), "build", "-I", dir,
			"-w", work, "-o", out, target];
		let co: testenv.commandout;
		command(dir, strings.concat("reject_", label, "_", tags[i]), av,
			&co);
		if (co.termination != exec.termination.EXIT || co.code == 0) {
			fail(label, strings.concat(drivers[i], " accepted invalid graph"));
		};
		if (!testenv.has(co.stderr, needle)) {
			fail(label, strings.concat(drivers[i], " diagnostic missing '",
				needle, "': ", co.stderr));
		};
		errors[i] = co.stderr;
		i += 1;
	};
	if (!testenv.same(errors[0], errors[2])) {
		fail(label, "C diagnostic changed across repeated builds");
	};
	if (!testenv.same(errors[1], errors[3])) {
		fail(label, "WW diagnostic changed across repeated builds");
	};
	let cb: str = diagnosticbody(errors[0]);
	let wb: str = diagnosticbody(errors[1]);
	if (!testenv.same(cb, wb)) {
		fail(label, strings.concat("C/WW diagnostic bodies differ: '", cb,
			"' vs '", wb, "'"));
	};
};

@test fn standalone_and_package_artifact() void = {
	let td: str = testenv.fresh();
	let app: str = strings.concat(td, "/app");
	mkdir(app);
	testenv.writefile(strings.concat(app, "/main.ww"), strings.concat(
		"package main;\n",
		"fn main() i32 = { return 23; };\n"));
	// Ordinary builds must not accidentally select test-only sources.
	testenv.writefile(strings.concat(app, "/broken_test.ww"),
		"package other;\nthis is deliberately invalid\n");
	let c1: str = strings.concat(td, "/standalone-c1");
	let c2: str = strings.concat(td, "/standalone-c2");
	let ww: str = strings.concat(td, "/standalone-ww");
	if (build(td, "ww", "standalone_c1", app, c1) != 0
	    || build(td, "ww", "standalone_c2", app, c2) != 0
	    || build(td, "ww_ww", "standalone_ww", app, ww) != 0) {
		fail("standalone", "manifest-free directory build failed");
	};
	let av1: []str = [c1];
	let av2: []str = [ww];
	if (code(td, "run_standalone_c", av1) != 23
	    || code(td, "run_standalone_ww", av2) != 23) {
		fail("standalone", "built executable returned the wrong value");
	};
	if (!testenv.same(testenv.readfile(c1), testenv.readfile(c2))) {
		fail("standalone", "two clean builds were not byte-identical");
	};

	let lib: str = strings.concat(td, "/libonly");
	mkdir(lib);
	testenv.writefile(strings.concat(lib, "/lib.ww"), strings.concat(
		"package libonly;\n",
		"export fn shown() i32 = { return 7; };\n",
		"fn hidden() i32 = { return 99; };\n"));
	let ca: str = strings.concat(td, "/libonly-c.a");
	let wa: str = strings.concat(td, "/libonly-w.a");
	let cav: []str = [testenv.driver("ww"), "build", "-p", "-I", td,
		"-o", ca, lib];
	let wav: []str = [testenv.driver("ww_ww"), "build", "-p", "-I", td,
		"-o", wa, lib];
	if (code(td, "build_package_c", cav) != 0
	    || code(td, "build_package_w", wav) != 0) {
		fail("package-artifact", "non-main package build failed");
	};
	if (!testenv.exists(strings.concat(ca, ".wwi"))
	    || !testenv.exists(strings.concat(wa, ".wwi"))) {
		fail("package-artifact", "missing compiler export sidecar");
	};
	if (!testenv.same(testenv.readfile(ca), testenv.readfile(wa))
	    || !testenv.same(testenv.readfile(strings.concat(ca, ".wwi")),
		testenv.readfile(strings.concat(wa, ".wwi")))) {
		fail("package-artifact", "C/WW package products differ");
	};
	let iface: str = testenv.readfile(strings.concat(ca, ".wwi"));
	if (!testenv.has(iface, "shown") || testenv.has(iface, "hidden")) {
		fail("package-artifact", "export interface crossed the private boundary");
	};
	testenv.clean(td);
};

@test fn self_contained_direct_exports() void = {
	let td: str = testenv.fresh();
	let dimensions: str = strings.concat(td, "/dimensions");
	let implementation: str = strings.concat(td, "/implementation");
	let api: str = strings.concat(td, "/api");
	let main: str = strings.concat(td, "/main");
	mkdir(dimensions); mkdir(implementation); mkdir(api); mkdir(main);
	let dimensionssrc: str = strings.concat(
		"package dimensions;\n",
		"export def WIDTH: i32 = 4;\n",
		"export def UNUSED_WIDTH: i32 = 8;\n");
	let implsrc: str = strings.concat(
		"package implementation;\n",
		"import dimensions;\n",
		"def PRIVATE_WIDTH: i32 = 3;\n",
		"export type Buffer = [PRIVATE_WIDTH]u8;\n",
		"export type PublicBuffer = [WIDTH]u8;\n",
		"export type CastBuffer = [(WIDTH: u64)]u8;\n",
		"export type Detail = struct { code: i64, };\n",
		"export type Member = struct { detail: Detail, payload: i64, };\n",
		"export type Unused = struct { noise: i32, };\n",
		"export def UNUSED: i32 = 99;\n",
		"type private_type = struct { secret: i32, };\n",
		"def private_value: i32 = 77;\n",
		"export fn construct(v: i32) Member = { return Member{detail=Detail{code=(v: i64) + 1i64}, payload=(v: i64) + 2i64}; };\n",
		"export fn unrelated() i32 = { return UNUSED; };\n",
		"fn hidden() i32 = { return private_value; };\n");
	let apisrc: str = strings.concat(
		"package api;\n",
		"import implementation;\n",
		"export type Member = struct { local: i32, };\n",
		"export fn produce(v: i32) implementation.Member = { return implementation.construct(v); };\n",
		"export fn score(m: implementation.Member) i32 = { return (m.detail.code + m.payload): i32; };\n",
		"export fn width_of(b: Buffer) i32 = { return len(b): i32; };\n",
		"export fn public_width_of(b: implementation.PublicBuffer) i32 = { return len(b): i32; };\n",
		"export fn cast_width_of(b: implementation.CastBuffer) i32 = { return len(b): i32; };\n");
	let mainsrc: str = strings.concat(
		"package main;\n",
		"import api;\n",
		"fn main() i32 = { let m = api.produce(19); let p: *i64 = alloc(api.score(m): i64)!; return (*p): i32; };\n");
	testenv.writefile(strings.concat(dimensions, "/dimensions.ww"), dimensionssrc);
	testenv.writefile(strings.concat(implementation, "/implementation.ww"),
		implsrc);
	testenv.writefile(strings.concat(api, "/api.ww"), apisrc);
	testenv.writefile(strings.concat(main, "/main.ww"), mainsrc);

	let outputs: []str = [strings.concat(td, "/direct-c1"),
		strings.concat(td, "/direct-c2"), strings.concat(td, "/direct-w")];
	let drivers: []str = ["ww", "ww", "ww_ww"];
	let tags: []str = ["direct_c1", "direct_c2", "direct_w"];
	let i: i32 = 0;
	for (i < outputs.len) {
		if (build(td, drivers[i], tags[i], main, outputs[i]) != 0) {
			fail("self-contained", strings.concat(drivers[i], " build failed"));
		};
		let runav: []str = [outputs[i]];
		if (code(td, strings.concat("run_", tags[i]), runav) != 41) {
			fail("self-contained", "implementation archive was not linked");
		};
		i += 1;
	};
	if (!testenv.same(testenv.readfile(outputs[0]), testenv.readfile(outputs[1]))
	    || !testenv.same(testenv.readfile(outputs[0]), testenv.readfile(outputs[2]))) {
		fail("self-contained", "clean C/C/WW executable outputs differ");
	};

	let cwork: str = strings.concat(outputs[0], ".sepwork/");
	let cwork2: str = strings.concat(outputs[1], ".sepwork/");
	let wwork: str = strings.concat(outputs[2], ".sepwork/");
	let apiiface: str = testenv.readfile(strings.concat(cwork, "api.wwi"));
	if (!testenv.same(apiiface, testenv.readfile(strings.concat(cwork2,
	    "api.wwi"))) || !testenv.same(apiiface, testenv.readfile(strings.concat(
	    wwork, "api.wwi")))) {
		fail("self-contained", "C/C/WW api exports differ");
	};
	if (!testenv.has(apiiface, "//ww:module implementation\n")
	    || !testenv.has(apiiface, "export type Buffer = [3]u8;")
	    || !testenv.has(apiiface, "export type PublicBuffer = [4]u8;")
	    || !testenv.has(apiiface, "export type CastBuffer = [4]u8;")
	    || !testenv.has(apiiface, "export type Detail = struct")
	    || testenv.occurrences(apiiface, "export type Member = struct") != 2) {
		fail("self-contained", "api export lacks the recursive public type facts");
	};
	if (testenv.has(apiiface, "//ww:module dimensions\n")
	    || testenv.has(apiiface, "WIDTH")
	    || testenv.has(apiiface, "export def UNUSED_WIDTH")
	    || testenv.has(apiiface, "PRIVATE_WIDTH")
	    || testenv.has(apiiface, "export type Unused")
	    || testenv.has(apiiface, "export def UNUSED")
	    || testenv.has(apiiface, "export fn construct")
	    || testenv.has(apiiface, "unrelated")
	    || testenv.has(apiiface, "private_type")
	    || testenv.has(apiiface, "private_value")
	    || testenv.has(apiiface, "hidden")) {
		fail("self-contained", "api export leaked unrelated or private declarations");
	};
	let expectedunit: str = strings.concat("//ww:module-reset main\n",
		mainsrc, "\n");
	if (!testenv.same(expectedunit, testenv.readfile(strings.concat(cwork,
	    "__root.unit.ww"))) || !testenv.same(expectedunit,
	    testenv.readfile(strings.concat(wwork, "__root.unit.ww")))) {
		fail("self-contained", "consumer unit was not exactly its owned source");
	};
	if (!testenv.exists(strings.concat(cwork, "implementation.a"))
	    || !testenv.exists(strings.concat(cwork, "dimensions.a"))) {
		fail("self-contained", "reachable archives missing from link closure");
	};

	let packages: []str = [strings.concat(td, "/api-c1.a"),
		strings.concat(td, "/api-c2.a"), strings.concat(td, "/api-w.a")];
	i = 0;
	for (i < packages.len) {
		let pav: []str = [testenv.driver(drivers[i]), "build", "-p", "-I", td,
			"-o", packages[i], api];
		if (code(td, strings.concat("package_", tags[i]), pav) != 0) {
			fail("self-contained", "ww build -p api failed");
		};
		i += 1;
	};
	if (!testenv.same(testenv.readfile(packages[0]), testenv.readfile(packages[1]))
	    || !testenv.same(testenv.readfile(packages[0]), testenv.readfile(packages[2]))
	    || !testenv.same(apiiface, testenv.readfile(strings.concat(packages[0],
	    ".wwi"))) || !testenv.same(apiiface, testenv.readfile(strings.concat(
	    packages[1], ".wwi"))) || !testenv.same(apiiface,
	    testenv.readfile(strings.concat(packages[2], ".wwi")))) {
		fail("self-contained", "deterministic package artifact/export mismatch");
	};

	testenv.writefile(strings.concat(td, "/deep-qualifier.ww"), strings.concat(
		"package main;\nimport api;\n",
		"fn main() i32 = { let m: implementation.Member; return 0; };\n"));
	rejectstable(td, "deep-qualifier", strings.concat(td,
		"/deep-qualifier.ww"), "unknown type 'implementation.Member'");
	testenv.writefile(strings.concat(td, "/deep-value.ww"), strings.concat(
		"package main;\nimport api;\n",
		"fn main() i32 = { return construct(1); };\n"));
	rejectstable(td, "deep-value", strings.concat(td, "/deep-value.ww"),
		"undefined: construct");
	testenv.writefile(strings.concat(td, "/deep-const.ww"), strings.concat(
		"package main;\nimport api;\n",
		"fn main() i32 = { return WIDTH; };\n"));
	rejectstable(td, "deep-const", strings.concat(td, "/deep-const.ww"),
		"undefined: WIDTH");
	testenv.writefile(strings.concat(td, "/deep-type.ww"), strings.concat(
		"package main;\nimport api;\n",
		"fn main() i32 = { let d: Detail; return 0; };\n"));
	rejectstable(td, "deep-type", strings.concat(td, "/deep-type.ww"),
		"unknown type 'Detail'");
	testenv.writefile(strings.concat(td, "/private-direct.ww"), strings.concat(
		"package main;\nimport implementation;\n",
		"fn main() i32 = { return implementation.hidden(); };\n"));
	rejectstable(td, "private-direct", strings.concat(td,
		"/private-direct.ww"), "has no exported declaration 'hidden'");
	testenv.clean(td);
};

fn writediamond(td: str, reverse: bool) str = {
	let shared: str = strings.concat(td, "/shared");
	let left: str = strings.concat(td, "/left");
	let right: str = strings.concat(td, "/right");
	let main: str = strings.concat(td, "/main");
	if (reverse) { mkdir(left); mkdir(main); mkdir(shared); mkdir(right); }
	else { mkdir(right); mkdir(shared); mkdir(main); mkdir(left); };
	let zsrc: str = strings.concat(
		"package shared;\n",
		"fn hidden() i32 = { return 91; };\n");
	let asrc: str = strings.concat(
		"package shared;\n",
		"export type token = struct { value: i32, };\n",
		"export fn base() i32 = { return 3; };\n");
	if (reverse) {
		testenv.writefile(strings.concat(shared, "/a.ww"), asrc);
		testenv.writefile(strings.concat(shared, "/z.ww"), zsrc);
	} else {
		testenv.writefile(strings.concat(shared, "/z.ww"), zsrc);
		testenv.writefile(strings.concat(shared, "/a.ww"), asrc);
	};
	testenv.writefile(strings.concat(left, "/left.ww"), strings.concat(
		"package left;\nimport shared;\nimport shared;\n",
		"export fn make() shared.token = { return shared.token{value=shared.base() + 1}; };\n"));
	testenv.writefile(strings.concat(right, "/right.ww"), strings.concat(
		"package right;\nimport shared;\n",
		"export fn value(t: shared.token) i32 = { return t.value + shared.base() + 2; };\n"));
	testenv.writefile(strings.concat(main, "/main.ww"), strings.concat(
		"package main;\nimport right;\nimport left;\n",
		"fn main() i32 = { return right.value(left.make()); };\n"));
	return main;
};

@test fn direct_and_diamond() void = {
	let td: str = testenv.fresh();
	let treea: str = strings.concat(td, "/tree-a"); mkdir(treea);
	let treeb: str = strings.concat(td, "/tree-b"); mkdir(treeb);
	let main: str = writediamond(treea, false);
	let shuffled: str = writediamond(treeb, true);
	let drivers: []str = ["ww", "ww_ww"];
	let tags: []str = ["c", "w"];
	let i: i32 = 0;
	for (i < drivers.len) {
		let out: str = strings.concat(td, "/diamond-", tags[i]);
		if (build(treea, drivers[i], strings.concat("diamond_", tags[i]),
		    main, out) != 0) {
			fail("diamond", strings.concat(drivers[i], " build failed"));
		};
		let av: []str = [out];
		if (code(td, strings.concat("run_diamond_", tags[i]), av) != 9) {
			fail("diamond", "linked program returned the wrong value");
		};
		let scratch: str = strings.concat(out, ".sepwork/");
		if (!testenv.exists(strings.concat(scratch, "shared.a"))
		    || testenv.exists(strings.concat(scratch, "shared.shared.a"))) {
			fail("diamond", "shared package was not interned exactly once");
		};
		let unit: str = testenv.readfile(strings.concat(scratch,
			"__root.unit.ww"));
		let rootbody: str = testenv.readfile(strings.concat(main, "/main.ww"));
		let wantroot: str = strings.concat("//ww:module-reset main\n", rootbody,
			"\n");
		if (!testenv.same(unit, wantroot) || testenv.has(unit,
			"//ww:module ")) {
			fail("diamond", "root unit contains non-owned export text");
		};
		let sharedunit: str = testenv.readfile(strings.concat(scratch,
			"shared.unit.ww"));
		let ap: i32 = testenv.pos(sharedunit, "export type token");
		let zp: i32 = testenv.pos(sharedunit, "fn hidden");
		if (ap < 0 || zp < 0 || ap >= zp) {
			fail("diamond", "package sources were not byte-sorted");
		};
		let leftiface: str = testenv.readfile(strings.concat(scratch,
			"left.wwi"));
		let rightiface: str = testenv.readfile(strings.concat(scratch,
			"right.wwi"));
		if (testenv.occurrences(leftiface, "import shared;") != 1) {
			fail("diamond", "duplicate import escaped into export data");
		};
		if (testenv.occurrences(leftiface, "export type token") != 1
		    || testenv.occurrences(rightiface, "export type token") != 1
		    || testenv.has(unit, "export type token")) {
			fail("diamond", "origin fact closure did not merge deterministically");
		};
		i += 1;
	};
	let shuffledout: str = strings.concat(td, "/diamond-c-shuffled");
	if (build(treeb, "ww", "diamond_c_shuffled", shuffled,
	    shuffledout) != 0) {
		fail("diamond", "shuffled directory build failed");
	};
	let firstout: str = strings.concat(td, "/diamond-c");
	if (!testenv.same(testenv.readfile(firstout),
	    testenv.readfile(shuffledout))) {
		fail("diamond", "shuffled directory enumeration changed output");
	};
	let firstscratch: str = strings.concat(firstout, ".sepwork/");
	let shuffledscratch: str = strings.concat(shuffledout, ".sepwork/");
	if (!testenv.same(testenv.readfile(strings.concat(firstscratch,
	    "__root.unit.ww")), testenv.readfile(strings.concat(shuffledscratch,
	    "__root.unit.ww"))) || !testenv.same(testenv.readfile(strings.concat(
	    firstscratch, "shared.unit.ww")), testenv.readfile(strings.concat(
	    shuffledscratch, "shared.unit.ww")))) {
		fail("diamond", "shuffled enumeration changed package units");
	};

	testenv.clean(td);
};

@test fn toolchain_library_root_stage_parity() void = {
	let td: str = testenv.fresh();
	let source: str = strings.concat(td, "/source library");
	let app: str = strings.concat(source, "/app");
	let dep: str = strings.concat(source, "/dep");
	let leaf: str = strings.concat(source, "/leaf");
	let runtime: str = strings.concat(td, "/runtime library");
	let decoy: str = strings.concat(runtime, "/app");
	let tools: str = strings.concat(td, "/tool wrappers");
	let cwd: str = strings.concat(td, "/isolated cwd");
	let defaultapp: str = strings.concat(td, "/default app");
	let fallbackbuf: []u8 = alloc([], os.PATH_MAX: u64)!;
	fallbackbuf.len = os.PATH_MAX;
	let fi: i32 = 0;
	for (fi < fallbackbuf.len) { fallbackbuf[fi] = 120u8; fi += 1; };
	let fallback: str = strings.frombytes(fallbackbuf);
	mkdir(source); mkdir(app); mkdir(dep); mkdir(leaf);
	mkdir(runtime); mkdir(decoy); mkdir(tools); mkdir(cwd); mkdir(defaultapp);
	testenv.writefile(strings.concat(leaf, "/leaf.ww"), strings.concat(
		"package leaf;\n",
		"export fn value() i32 = { return 40; };\n"));
	testenv.writefile(strings.concat(dep, "/dep.ww"), strings.concat(
		"package dep;\nimport leaf;\n",
		"export fn value() i32 = { return leaf.value() + 2; };\n"));
	testenv.writefile(strings.concat(app, "/app.ww"), strings.concat(
		"package main;\nimport dep;\n",
		"fn main() i32 = { return dep.value(); };\n"));
	testenv.writefile(strings.concat(decoy, "/app.ww"),
		"package main;\nfn main() i32 = { return 7; };\n");
	testenv.writefile(strings.concat(defaultapp, "/main.ww"), strings.concat(
		"package main;\nimport types;\n",
		"fn main() i32 = { return (types.I8_MAX: i32) - 85; };\n"));
	testenv.writefile(strings.concat(runtime, "/libwwrt.a"),
		testenv.readfile(strings.concat(testenv.repo(), "/out/lib/libwwrt.a")));

	let compiler: str = strings.concat(tools, "/w6c wrapper.sh");
	let assembler: str = strings.concat(tools, "/w6a wrapper.sh");
	let linker: str = strings.concat(tools, "/w6l wrapper.sh");
	testenv.writeexecutable(compiler, strings.concat(
		"#!/bin/sh\n",
		"printf 'BEGIN' >> \"$WW_ROOT_COMPILER_TRACE\"\n",
		"for arg in \"$@\"; do printf '<%s>' \"$arg\" >> ",
			"\"$WW_ROOT_COMPILER_TRACE\"; done\n",
		"printf '\\n' >> \"$WW_ROOT_COMPILER_TRACE\"\n",
		"exec \"$WW_ROOT_REAL_COMPILER\" \"$@\"\n"));
	testenv.writeexecutable(assembler, strings.concat(
		"#!/bin/sh\n",
		"printf 'BEGIN' >> \"$WW_ROOT_ASSEMBLER_TRACE\"\n",
		"for arg in \"$@\"; do printf '<%s>' \"$arg\" >> ",
			"\"$WW_ROOT_ASSEMBLER_TRACE\"; done\n",
		"printf '\\n' >> \"$WW_ROOT_ASSEMBLER_TRACE\"\n",
		"exec \"$WW_ROOT_REAL_ASSEMBLER\" \"$@\"\n"));
	testenv.writeexecutable(linker, strings.concat(
		"#!/bin/sh\n",
		"printf 'BEGIN' >> \"$WW_ROOT_LINKER_TRACE\"\n",
		"for arg in \"$@\"; do printf '<%s>' \"$arg\" >> ",
			"\"$WW_ROOT_LINKER_TRACE\"; done\n",
		"printf '\\n' >> \"$WW_ROOT_LINKER_TRACE\"\n",
		"exec \"$WW_ROOT_REAL_LINKER\" \"$@\"\n"));

	let stages: []str = ["ww", "ww_ww"];
	let compilers: []str = ["w6c", "w6c_ww"];
	let assemblers: []str = ["w6a", "w6a_ww"];
	let linkers: []str = ["w6l", "w6l_ww"];
	let tags: []str = ["c", "ww"];
	let modes: []str = ["archive", "overlong-fallback"];
	let runtimes: []str = [runtime, fallback];
	let bin: str = strings.concat(td, "/published binary");
	let workroot: str = strings.concat(bin, ".sepwork");
	let work: str = strings.concat(workroot, "/");
	let mi: i32 = 0;
	for (mi < modes.len) {
		let referenceunit: str = "";
		let referencewwi: str = "";
		let referencearchive: str = "";
		let referencerootwwi: str = "";
		let referencerootarchive: str = "";
		let referencebin: str = "";
		let referencecompiler: str = "";
		let referenceassembler: str = "";
		let referencelinker: str = "";
		let si: i32 = 0;
		for (si < stages.len) {
			let prefix: str = strings.concat(modes[mi], "-", tags[si]);
			let compilertrace: str = strings.concat(td, "/", prefix,
				" compiler trace");
			let assemblertrace: str = strings.concat(td, "/", prefix,
				" assembler trace");
			let linkertrace: str = strings.concat(td, "/", prefix,
				" linker trace");
			testenv.writefile(compilertrace, "");
			testenv.writefile(assemblertrace, "");
			testenv.writefile(linkertrace, "");
			let env: []str = roottraceenv(source, runtimes[mi],
				compiler, assembler, linker,
				compilertrace, assemblertrace, linkertrace,
				testenv.driver(compilers[si]),
				testenv.driver(assemblers[si]),
				testenv.driver(linkers[si]));
			let av: []str = [testenv.driver(stages[si]), "build", "-o", bin,
				"app"];
			let out: testenv.commandout;
			testenv.runcommandenv(cwd, td, strings.concat("library-root-", prefix),
				av, env, tmo(), &out);
			if (out.termination != exec.termination.EXIT || out.code != 0
			    || out.stderr.len != 0) {
				fail("library-roots", strings.concat(prefix, " build failed: ",
					out.stderr));
			};

			let rootunit: str = testenv.readfile(strings.concat(work,
				"__root.unit.ww"));
			let depunit: str = testenv.readfile(strings.concat(work,
				"dep.unit.ww"));
			if (!testenv.has(rootunit, "//ww:module-reset main\npackage main;")
			    || testenv.has(rootunit, "//ww:module ")
			    || !testenv.has(depunit, "//ww:module-reset dep\npackage dep;")
			    || testenv.has(depunit, "//ww:module ")) {
				fail("library-roots", "package units contain non-owned export text");
			};
			if (!testenv.exists(strings.concat(work, "leaf.wwi"))
			    || !testenv.exists(strings.concat(work, "leaf.a"))
			    || !testenv.exists(strings.concat(work, "dep.wwi"))
			    || !testenv.exists(strings.concat(work, "dep.a"))
			    || !testenv.exists(strings.concat(work, "__root.o"))
			    || !testenv.exists(strings.concat(work, "__root.wwi"))
			    || !testenv.exists(strings.concat(work, "__root.a"))) {
				fail("library-roots", "package artifacts do not match root ownership");
			};
			let ctrace: str = testenv.readfile(compilertrace);
			let atrace: str = testenv.readfile(assemblertrace);
			let ltrace: str = testenv.readfile(linkertrace);
			if (testenv.occurrences(ctrace, strings.concat("<", work,
				"leaf.unit.ww>")) != 1
			    || testenv.occurrences(ctrace, strings.concat("<", work,
				"dep.unit.ww>")) != 1
			    || testenv.occurrences(ctrace, strings.concat("<", work,
				"__root.unit.ww>")) != 1
			    || testenv.pos(ctrace, strings.concat("<", work,
				"leaf.unit.ww>")) >= testenv.pos(ctrace, strings.concat("<",
				work, "dep.unit.ww>"))
			    || testenv.pos(ctrace, strings.concat("<", work,
				"dep.unit.ww>")) >= testenv.pos(ctrace, strings.concat("<",
				work, "__root.unit.ww>"))) {
				fail("library-roots", "compiler actions were not deterministic postorder");
			};
			if (!testenv.has(ctrace, strings.concat(
				"BEGIN<-c><--import><leaf><", work, "leaf.wwi><-I><", work,
				"dep.wwi><-o><", work,
				"dep.s><", work, "dep.unit.ww>"))
			    || !testenv.has(ctrace, strings.concat(
				"BEGIN<--entry><-c><--import><dep><", work,
				"dep.wwi><-I><", work, "__root.wwi><-o><", work,
				"__root.s><", work, "__root.unit.ww>"))
			    || testenv.occurrences(atrace, "\n") != 3
			    || !testenv.has(atrace, strings.concat("BEGIN<-o><", work,
				"dep.o><", work, "dep.s>"))) {
				fail("library-roots", "compiler or assembler argv changed");
			};
			if (testenv.occurrences(ltrace, "\n") != 1
			    || !testenv.has(ltrace, strings.concat("BEGIN<-o><", bin, "><",
				work, "__root.a>"))
			    || testenv.pos(ltrace, strings.concat("<", work, "dep.a>")) < 0
			    || testenv.pos(ltrace, strings.concat("<", work, "leaf.a>"))
				< testenv.pos(ltrace, strings.concat("<", work, "dep.a>"))
			    || testenv.has(ltrace, ".wwi>")) {
				fail("library-roots", "linker did not receive the reachable archive closure");
			};
			if (mi == 0) {
				if (!testenv.has(ltrace, strings.concat("<", runtime,
					"/libwwrt.a>"))
				    || testenv.has(ltrace, strings.concat("<", testenv.repo(),
					"/out/lib/libwwrt.a>"))) {
					fail("library-roots", "WW_LIB did not select the runtime archive");
				};
			} else {
				if (!testenv.has(ltrace, strings.concat("<", testenv.repo(),
					"/out/bin/../obj/rt/start.o>"))
				    || !testenv.has(ltrace, strings.concat("<", testenv.repo(),
					"/out/bin/../obj/rt/syscall.o>"))) {
					fail("library-roots", "missing runtime archive did not use object fallback");
				};
			};
			let runav: []str = [bin];
			if (code(cwd, strings.concat("run-library-root-", prefix), runav)
			    != 42) {
				fail("library-roots", "WW_SRCLIB did not win over the WW_LIB decoy");
			};
			if (si == 0) {
				referenceunit = strings.dup(rootunit);
				referencewwi = strings.dup(testenv.readfile(strings.concat(work,
					"dep.wwi")));
				referencearchive = strings.dup(testenv.readfile(strings.concat(work,
					"dep.a")));
				referencerootwwi = strings.dup(testenv.readfile(strings.concat(work,
					"__root.wwi")));
				referencerootarchive = strings.dup(testenv.readfile(strings.concat(work,
					"__root.a")));
				referencebin = strings.dup(testenv.readfile(bin));
				referencecompiler = strings.dup(ctrace);
				referenceassembler = strings.dup(atrace);
				referencelinker = strings.dup(ltrace);
			} else {
				if (!testenv.same(referenceunit, rootunit)
				    || !testenv.same(referencewwi, testenv.readfile(strings.concat(
					work, "dep.wwi")))
				    || !testenv.same(referencearchive, testenv.readfile(strings.concat(
					work, "dep.a")))
				    || !testenv.same(referencerootwwi,
					testenv.readfile(strings.concat(work, "__root.wwi")))
				    || !testenv.same(referencerootarchive,
					testenv.readfile(strings.concat(work, "__root.a")))
				    || !testenv.same(referencebin, testenv.readfile(bin))
				    || !testenv.same(referencecompiler, ctrace)
				    || !testenv.same(referenceassembler, atrace)
				    || !testenv.same(referencelinker, ltrace)) {
					fail("library-roots", "Cstage and WWstage products or argv differ");
				};
			};
			if (mi == 0) {
				let missing: []str = [testenv.driver(stages[si]), "build", "-o",
					strings.concat(td, "/missing binary"), "absent"];
				testenv.runcommandenv(cwd, td, strings.concat("library-missing-",
					tags[si]), missing, env, tmo(), &out);
				if (out.termination != exec.termination.EXIT || out.code != 1
				    || !testenv.same(out.stderr,
					"ww build: cannot find module absent\n")) {
					fail("library-roots", "bare-target diagnostic differs by stage");
				};
			};
			testenv.clean(workroot);
			assert(os.remove(bin) == 0);
			si += 1;
		};
		mi += 1;
	};

	let emptyunitreference: str = "";
	let emptywwireference: str = "";
	let emptyarchivereference: str = "";
	let emptybinreference: str = "";
	let emptycompilerreference: str = "";
	let emptyassemblerreference: str = "";
	let emptylinkerreference: str = "";
	let emptyout: str = strings.concat(td, "/empty published binary");
	let si: i32 = 0;
	for (si < stages.len) {
		let outpath: str = emptyout;
		let emptyworkroot: str = strings.concat(outpath, ".sepwork");
		let emptywork: str = strings.concat(emptyworkroot, "/");
		let compilertrace: str = strings.concat(td, "/empty-", tags[si],
			" compiler trace");
		let assemblertrace: str = strings.concat(td, "/empty-", tags[si],
			" assembler trace");
		let linkertrace: str = strings.concat(td, "/empty-", tags[si],
			" linker trace");
		testenv.writefile(compilertrace, "");
		testenv.writefile(assemblertrace, "");
		testenv.writefile(linkertrace, "");
		let emptyenv: []str = roottraceenv("", "",
			compiler, assembler, linker,
			compilertrace, assemblertrace, linkertrace,
			testenv.driver(compilers[si]),
			testenv.driver(assemblers[si]),
			testenv.driver(linkers[si]));
		let av: []str = [testenv.driver(stages[si]), "build", "-o", outpath,
			defaultapp];
		let out: testenv.commandout;
		testenv.runcommandenv(cwd, td, strings.concat("empty-library-",
			tags[si]), av, emptyenv, tmo(), &out);
		let rootunit: str = testenv.readfile(strings.concat(emptywork,
			"__root.unit.ww"));
		let ctrace: str = testenv.readfile(compilertrace);
		let atrace: str = testenv.readfile(assemblertrace);
		let ltrace: str = testenv.readfile(linkertrace);
		let runav: []str = [outpath];
		if (out.termination != exec.termination.EXIT || out.code != 0
		    || out.stderr.len != 0
		    || code(cwd, strings.concat("run-empty-library-", tags[si]),
			runav) != 42) {
			fail("library-roots", "empty override did not use default roots");
		};
		if (!testenv.has(rootunit, "//ww:module-reset main\npackage main;")
		    || testenv.has(rootunit, "//ww:module ")
		    || !testenv.exists(strings.concat(emptywork, "types.wwi"))
		    || !testenv.exists(strings.concat(emptywork, "types.a"))
		    || testenv.occurrences(ctrace, strings.concat("<", emptywork,
			"types.unit.ww>")) != 1
		    || testenv.occurrences(atrace, "\n") != 2) {
			fail("library-roots", "empty WW_SRCLIB did not use the default source root");
		};
		if (testenv.occurrences(ltrace, "\n") != 1
		    || !testenv.has(ltrace, strings.concat("<", emptywork, "types.a>"))
		    || !testenv.has(ltrace, strings.concat("<", testenv.repo(),
			"/out/bin/../lib/libwwrt.a>"))
		    || testenv.has(ltrace, "/../obj/rt/start.o>")
		    || testenv.has(ltrace, "/../obj/rt/syscall.o>")) {
			fail("library-roots", "empty WW_LIB did not use the default runtime archive");
		};
		if (si == 0) {
			emptyunitreference = strings.dup(rootunit);
			emptywwireference = strings.dup(testenv.readfile(strings.concat(
				emptywork, "types.wwi")));
			emptyarchivereference = strings.dup(testenv.readfile(strings.concat(
				emptywork, "types.a")));
			emptybinreference = strings.dup(testenv.readfile(outpath));
			emptycompilerreference = strings.dup(ctrace);
			emptyassemblerreference = strings.dup(atrace);
			emptylinkerreference = strings.dup(ltrace);
		} else { if (!testenv.same(emptyunitreference, rootunit)
		    || !testenv.same(emptywwireference, testenv.readfile(strings.concat(
			emptywork, "types.wwi")))
		    || !testenv.same(emptyarchivereference, testenv.readfile(
			strings.concat(emptywork, "types.a")))
		    || !testenv.same(emptybinreference, testenv.readfile(outpath))
		    || !testenv.same(emptycompilerreference, ctrace)
		    || !testenv.same(emptyassemblerreference, atrace)
		    || !testenv.same(emptylinkerreference, ltrace)) {
			fail("library-roots", "empty-root fallback changed stage output or argv");
		}; };
		testenv.clean(emptyworkroot);
		assert(os.remove(outpath) == 0);
		si += 1;
	};
	testenv.clean(td);
};

// Unit bytes cannot identify driver-owned graph, archive, and commit semantics.
// Keep their executable content beside the compiler/assembler identities so a
// warm voucher never crosses a builder change.
@test fn persistent_build_reuse_tracks_driver_identity() void = {
	let td: str = testenv.fresh();
	let source: str = strings.concat(td, "/source tree");
	let app: str = strings.concat(source, "/app");
	let dep: str = strings.concat(source, "/dep");
	let leaf: str = strings.concat(source, "/leaf");
	let tools: str = strings.concat(td, "/tool wrappers");
	let cdrivers: str = strings.concat(td, "/c driver copy");
	let wdrivers: str = strings.concat(td, "/ww driver copy");
	let cwd: str = strings.concat(td, "/isolated cwd");
	let work: str = strings.concat(td, "/persistent work");
	let bin: str = strings.concat(td, "/published binary");
	mkdir(source); mkdir(app); mkdir(dep); mkdir(leaf); mkdir(tools);
	mkdir(cdrivers); mkdir(wdrivers); mkdir(cwd); mkdir(work);
	testenv.writefile(strings.concat(leaf, "/leaf.ww"), strings.concat(
		"package leaf;\n",
		"export fn value() i32 = { return 40; };\n"));
	testenv.writefile(strings.concat(dep, "/dep.ww"), strings.concat(
		"package dep;\nimport leaf;\n",
		"export fn value() i32 = { return leaf.value() + 2; };\n"));
	testenv.writefile(strings.concat(app, "/main.ww"), strings.concat(
		"package main;\nimport dep;\n",
		"fn main() i32 = { return dep.value(); };\n"));

	let compiler: str = strings.concat(tools, "/w6c wrapper.sh");
	let assembler: str = strings.concat(tools, "/w6a wrapper.sh");
	let linker: str = strings.concat(tools, "/w6l wrapper.sh");
	testenv.writeexecutable(compiler, strings.concat(
		"#!/bin/sh\n",
		"printf 'BEGIN' >> \"$WW_ROOT_COMPILER_TRACE\"\n",
		"for arg in \"$@\"; do printf '<%s>' \"$arg\" >> ",
			"\"$WW_ROOT_COMPILER_TRACE\"; done\n",
		"printf '\\n' >> \"$WW_ROOT_COMPILER_TRACE\"\n",
		"exec \"$WW_ROOT_REAL_COMPILER\" \"$@\"\n"));
	testenv.writeexecutable(assembler, strings.concat(
		"#!/bin/sh\n",
		"printf 'BEGIN' >> \"$WW_ROOT_ASSEMBLER_TRACE\"\n",
		"for arg in \"$@\"; do printf '<%s>' \"$arg\" >> ",
			"\"$WW_ROOT_ASSEMBLER_TRACE\"; done\n",
		"printf '\\n' >> \"$WW_ROOT_ASSEMBLER_TRACE\"\n",
		"exec \"$WW_ROOT_REAL_ASSEMBLER\" \"$@\"\n"));
	testenv.writeexecutable(linker, strings.concat(
		"#!/bin/sh\n",
		"printf 'BEGIN' >> \"$WW_ROOT_LINKER_TRACE\"\n",
		"for arg in \"$@\"; do printf '<%s>' \"$arg\" >> ",
			"\"$WW_ROOT_LINKER_TRACE\"; done\n",
		"printf '\\n' >> \"$WW_ROOT_LINKER_TRACE\"\n",
		"exec \"$WW_ROOT_REAL_LINKER\" \"$@\"\n"));

	let stages: []str = ["ww", "ww_ww"];
	let compilers: []str = ["w6c", "w6c_ww"];
	let assemblers: []str = ["w6a", "w6a_ww"];
	let linkers: []str = ["w6l", "w6l_ww"];
	let tags: []str = ["c", "ww"];
	let copied: []str = [strings.concat(cdrivers, "/ww"),
		strings.concat(wdrivers, "/ww_ww")];
	let runtime: str = strings.concat(testenv.repo(), "/out/lib");
	let referenceunit: str = "";
	let referencewwi: str = "";
	let referencearchive: str = "";
	let referencebin: str = "";
	let referencecompiler: str = "";
	let referenceassembler: str = "";
	let referencelinker: str = "";
	let referenceerror: str = "";
	let si: i32 = 0;
	for (si < stages.len) {
		let compilertrace: str = strings.concat(td, "/", tags[si],
			" compiler trace");
		let assemblertrace: str = strings.concat(td, "/", tags[si],
			" assembler trace");
		let linkertrace: str = strings.concat(td, "/", tags[si],
			" linker trace");
		testenv.writefile(compilertrace, "");
		testenv.writefile(assemblertrace, "");
		testenv.writefile(linkertrace, "");
		let driverbytes: str = testenv.readfile(testenv.driver(stages[si]));
		testenv.writeexecutable(copied[si], driverbytes);
		let env: []str = roottraceenv(source, runtime,
			compiler, assembler, linker,
			compilertrace, assemblertrace, linkertrace,
			testenv.driver(compilers[si]),
			testenv.driver(assemblers[si]),
			testenv.driver(linkers[si]));
		let av: []str = [copied[si], "build", "-w", work,
			"-o", bin, "app"];
		let out: testenv.commandout;
		testenv.runcommandenv(cwd, td, strings.concat("driver-cold-",
			tags[si]), av, env, tmo(), &out);
		if (out.termination != exec.termination.EXIT || out.code != 0
		    || out.stderr.len != 0) {
			fail("driver-identity", strings.concat(tags[si],
				" cold build failed: ", out.stderr));
		};

		let rootunitpath: str = strings.concat(work, "/__root.unit.ww");
		let depunitpath: str = strings.concat(work, "/dep.unit.ww");
		let rootunit: str = testenv.readfile(rootunitpath);
		let depunit: str = testenv.readfile(depunitpath);
		if (!testenv.has(rootunit, "//ww:module-reset main\npackage main;")
		    || testenv.has(rootunit, "//ww:module ")
		    || !testenv.has(depunit, "//ww:module-reset dep\npackage dep;")
		    || testenv.has(depunit, "//ww:module ")) {
			fail("driver-identity", "warm units contain non-owned export text");
		};
		if (!testenv.exists(strings.concat(work, "/leaf.wwi"))
		    || !testenv.exists(strings.concat(work, "/leaf.a"))
		    || !testenv.exists(strings.concat(work, "/dep.wwi"))
		    || !testenv.exists(strings.concat(work, "/dep.a"))
		    || !testenv.exists(strings.concat(work, "/__root.wwi"))
		    || !testenv.exists(strings.concat(work, "/__root.a"))
		    || !testenv.same(testenv.readfile(strings.concat(work,
			"/.wwtool.ww")), testenv.readfile(copied[si]))
		    || !testenv.same(testenv.readfile(strings.concat(work,
			"/.wwtool.w6c")), testenv.readfile(compiler))
		    || !testenv.same(testenv.readfile(strings.concat(work,
			"/.wwtool.w6a")), testenv.readfile(assembler))
		    || !testenv.same(testenv.readfile(strings.concat(work,
			"/.wwtool.stamp")),
			"ww workdir fmt 7 mode build asm 0\n")) {
			fail("driver-identity", "persistent artifacts or identities are incomplete");
		};
		let coldwwi: str = testenv.readfile(strings.concat(work, "/dep.wwi"));
		let coldarchive: str = testenv.readfile(strings.concat(work, "/dep.a"));
		let coldbin: str = testenv.readfile(bin);
		let coldcompiler: str = testenv.readfile(compilertrace);
		let coldassembler: str = testenv.readfile(assemblertrace);
		let coldlinker: str = testenv.readfile(linkertrace);
		if (testenv.occurrences(coldcompiler, "\n") != 3
		    || !testenv.has(coldcompiler, strings.concat(
			"BEGIN<-c><--import><leaf><", work, "/leaf.wwi><-I><", work,
			"/dep.wwi.new><-o><", work,
			"/dep.s.new><", work, "/dep.unit.new>"))
		    || !testenv.has(coldcompiler, strings.concat(
			"BEGIN<--entry><-c><--import><dep><", work,
			"/dep.wwi><-I><", work, "/__root.wwi.new><-o><", work,
			"/__root.s.new><", work,
			"/__root.unit.new>"))
		    || testenv.occurrences(coldassembler, "\n") != 3
		    || !testenv.has(coldassembler, strings.concat(
			"BEGIN<-o><", work, "/dep.o.new><", work,
			"/dep.s.new>"))) {
			fail("driver-identity", "cold compiler or assembler argv changed");
		};
		if (testenv.occurrences(coldlinker, "\n") != 1
		    || !testenv.has(coldlinker, strings.concat("BEGIN<-o><", bin,
			"><", work, "/__root.a>"))
		    || testenv.pos(coldlinker, strings.concat("<", work,
			"/dep.a>")) < 0
		    || testenv.pos(coldlinker, strings.concat("<", work,
			"/leaf.a>")) < testenv.pos(coldlinker, strings.concat("<",
			work, "/dep.a>"))
		    || !testenv.has(coldlinker, strings.concat("<", runtime,
			"/libwwrt.a>"))
		    || testenv.has(coldlinker, ".wwi>")) {
			fail("driver-identity", "cold link omitted the reachable archive closure");
		};
		let runav: []str = [bin];
		if (code(cwd, strings.concat("driver-cold-run-", tags[si]), runav)
		    != 42) {
			fail("driver-identity", "cold binary returned the wrong value");
		};

		testenv.writefile(strings.concat(leaf, "/extra.ww"), strings.concat(
			"package leaf;\n",
			"export fn unchanged_api() i32 = { return 1; };\n"));
		testenv.runcommandenv(cwd, td, strings.concat("driver-export-change-",
			tags[si]), av, env, tmo(), &out);
		if (out.termination != exec.termination.EXIT || out.code != 0
		    || out.stderr.len != 0) {
			fail("driver-identity", "dependency export-change build failed");
		};
		let changedexportcompiler: str = testenv.readfile(compilertrace);
		let changedexportassembler: str = testenv.readfile(assemblertrace);
		if (testenv.occurrences(changedexportcompiler, strings.concat("<", work,
			"/leaf.unit.new>")) != 2
		    || testenv.occurrences(changedexportcompiler, strings.concat("<", work,
			"/dep.unit.new>")) != 2
		    || testenv.occurrences(changedexportcompiler, strings.concat("<", work,
			"/__root.unit.new>")) != 1
		    || testenv.occurrences(changedexportcompiler, "\n") != 5
		    || testenv.occurrences(changedexportassembler, "\n") != 5) {
			fail("driver-identity", "changed export did not stop at an unchanged importer export");
		};
		if (code(cwd, strings.concat("driver-export-change-run-", tags[si]),
			runav) != 42) {
			fail("driver-identity", "export-change binary returned the wrong value");
		};
		let changedexportbin: str = testenv.readfile(bin);
		let beforewarmcompiler: str = strings.dup(changedexportcompiler);
		let beforewarmassembler: str = strings.dup(changedexportassembler);

		testenv.runcommandenv(cwd, td, strings.concat("driver-warm-",
			tags[si]), av, env, tmo(), &out);
		if (out.termination != exec.termination.EXIT || out.code != 0
		    || out.stderr.len != 0
		    || !testenv.same(beforewarmcompiler, testenv.readfile(compilertrace))
		    || !testenv.same(beforewarmassembler, testenv.readfile(assemblertrace))
		    || testenv.occurrences(testenv.readfile(linkertrace), "\n") != 3
		    || !testenv.same(rootunit, testenv.readfile(rootunitpath))
		    || !testenv.same(changedexportbin, testenv.readfile(bin))) {
			fail("driver-identity", "unchanged warm build did not reuse packages");
		};
		assert(os.remove(strings.concat(leaf, "/extra.ww")) == 0);
		testenv.runcommandenv(cwd, td, strings.concat("driver-export-restore-",
			tags[si]), av, env, tmo(), &out);
		if (out.termination != exec.termination.EXIT || out.code != 0
		    || out.stderr.len != 0
		    || testenv.occurrences(testenv.readfile(compilertrace), strings.concat(
			"<", work, "/leaf.unit.new>")) != 3
		    || testenv.occurrences(testenv.readfile(compilertrace), strings.concat(
			"<", work, "/dep.unit.new>")) != 3
		    || testenv.occurrences(testenv.readfile(compilertrace), strings.concat(
			"<", work, "/__root.unit.new>")) != 1
		    || testenv.occurrences(testenv.readfile(compilertrace), "\n") != 7
		    || testenv.occurrences(testenv.readfile(assemblertrace), "\n") != 7
		    || !testenv.same(coldbin, testenv.readfile(bin))) {
			fail("driver-identity", "restored export did not rebuild only its direct importer");
		};

		assert(os.remove(copied[si]) == 0);
		testenv.writeexecutable(copied[si], strings.concat(driverbytes,
			"\nww driver identity mutation\n"));
		testenv.runcommandenv(cwd, td, strings.concat("driver-changed-",
			tags[si]), av, env, tmo(), &out);
		if (out.termination != exec.termination.EXIT || out.code != 0
		    || out.stderr.len != 0) {
			fail("driver-identity", strings.concat(tags[si],
				" changed-driver build failed: ", out.stderr));
		};
		let changedcompiler: str = testenv.readfile(compilertrace);
		let changedassembler: str = testenv.readfile(assemblertrace);
		let changedlinker: str = testenv.readfile(linkertrace);
		if (testenv.occurrences(changedcompiler, strings.concat("<", work,
			"/leaf.unit.new>")) != 4
		    || testenv.occurrences(changedcompiler, strings.concat("<", work,
			"/dep.unit.new>")) != 4
		    || testenv.occurrences(changedcompiler, strings.concat("<", work,
			"/__root.unit.new>")) != 2
		    || testenv.occurrences(changedcompiler, "\n") != 10
		    || testenv.occurrences(changedassembler, "\n") != 10
		    || testenv.occurrences(changedlinker, "\n") != 5) {
			fail("driver-identity", "driver change reused stale package actions");
		};
		if (!testenv.same(testenv.readfile(strings.concat(work,
			"/.wwtool.ww")), testenv.readfile(copied[si]))
		    || !testenv.same(rootunit, testenv.readfile(rootunitpath))
		    || !testenv.same(coldwwi, testenv.readfile(strings.concat(work,
			"/dep.wwi")))
		    || !testenv.same(coldarchive, testenv.readfile(strings.concat(work,
			"/dep.a")))
		    || !testenv.same(coldbin, testenv.readfile(bin))
		    || code(cwd, strings.concat("driver-changed-run-", tags[si]),
			runav) != 42) {
			fail("driver-identity", "driver invalidation changed package products");
		};

		let beforecompiler: str = strings.dup(changedcompiler);
		let beforeassembler: str = strings.dup(changedassembler);
		let beforelinker: str = strings.dup(changedlinker);
		let missingwork: str = strings.concat(td, "/missing workdir");
		let missingbin: str = strings.concat(td, "/missing binary");
		let badav: []str = [copied[si], "build", "-w", missingwork,
			"-o", missingbin, "app"];
		testenv.runcommandenv(cwd, td, strings.concat("driver-missing-",
			tags[si]), badav, env, tmo(), &out);
		let wantdiag: str = strings.concat("ww: workdir ", missingwork,
			" is not a directory\n");
		if (out.termination != exec.termination.EXIT || out.code != 1
		    || !testenv.same(out.stderr, wantdiag)
		    || !testenv.same(beforecompiler, testenv.readfile(compilertrace))
		    || !testenv.same(beforeassembler, testenv.readfile(assemblertrace))
		    || !testenv.same(beforelinker, testenv.readfile(linkertrace))
		    || testenv.exists(missingbin)) {
			fail("driver-identity", "invalid workdir crossed the tool boundary");
		};

		if (si == 0) {
			referenceunit = strings.dup(rootunit);
			referencewwi = strings.dup(coldwwi);
			referencearchive = strings.dup(coldarchive);
			referencebin = strings.dup(coldbin);
			referencecompiler = strings.dup(changedcompiler);
			referenceassembler = strings.dup(changedassembler);
			referencelinker = strings.dup(changedlinker);
			referenceerror = strings.dup(out.stderr);
		} else { if (!testenv.same(referenceunit, rootunit)
		    || !testenv.same(referencewwi, coldwwi)
		    || !testenv.same(referencearchive, coldarchive)
		    || !testenv.same(referencebin, coldbin)
		    || !testenv.same(referencecompiler, changedcompiler)
		    || !testenv.same(referenceassembler, changedassembler)
		    || !testenv.same(referencelinker, changedlinker)
		    || !testenv.same(referenceerror, out.stderr)) {
			fail("driver-identity", "Cstage and WWstage warm behavior differs");
		}; };
		testenv.clean(work);
		assert(os.remove(bin) == 0);
		if (si + 1 < stages.len) { mkdir(work); };
		si += 1;
	};
	testenv.clean(td);
};

@test fn builtin_type_precedence() void = {
	let td: str = testenv.fresh();
	let dep: str = strings.concat(td, "/builtinshadow"); mkdir(dep);
	let main: str = strings.concat(td, "/main"); mkdir(main);
	testenv.writefile(strings.concat(dep, "/dep.ww"), strings.concat(
		"package builtinshadow;\n",
		"export type i32 = i8;\n",
		"export fn width() i32 = { return size(i32): i32; };\n"));
	testenv.writefile(strings.concat(main, "/main.ww"), strings.concat(
		"package main;\nimport builtinshadow;\n",
		"fn main() i32 = { return builtinshadow.width(); };\n"));
	let drivers: []str = ["ww", "ww_ww"];
	let tags: []str = ["c", "w"];
	let outputs: []str = ["", ""];
	let i: i32 = 0;
	for (i < drivers.len) {
		outputs[i] = strings.concat(td, "/builtin-", tags[i]);
		if (build(td, drivers[i], strings.concat("builtin_", tags[i]),
		    main, outputs[i]) != 0) {
			fail("builtin-type", strings.concat(drivers[i], " build failed"));
		};
		let av: []str = [outputs[i]];
		if (code(td, strings.concat("run_builtin_", tags[i]), av) != 4) {
			fail("builtin-type", strings.concat(drivers[i],
				" let an imported type shadow intrinsic i32"));
		};
		i += 1;
	};
	if (!testenv.same(testenv.readfile(outputs[0]),
	    testenv.readfile(outputs[1]))) {
		fail("builtin-type", "C/WW products differ");
	};
	testenv.clean(td);
};

@test fn export_visibility() void = {
	let td: str = testenv.fresh();
	let main: str = writediamond(td, false);
	// The successful diamond already proves a direct exported declaration.
	testenv.writefile(strings.concat(td, "/private.ww"), strings.concat(
		"package main;\nimport shared;\n",
		"fn main() i32 = { return shared.hidden(); };\n"));
	rejectstable(td, "private", strings.concat(td, "/private.ww"),
		"has no exported declaration 'hidden'");
	testenv.writefile(strings.concat(td, "/transitive.ww"), strings.concat(
		"package main;\nimport left;\n",
		"fn main() i32 = { return shared.base(); };\n"));
	rejectstable(td, "transitive", strings.concat(td, "/transitive.ww"),
		"package 'shared' is not directly imported");
	testenv.writefile(strings.concat(td, "/transitive-bare-value.ww"),
		strings.concat("package main;\nimport left;\n",
		"fn main() i32 = { return base(); };\n"));
	rejectstable(td, "transitive-bare-value",
		strings.concat(td, "/transitive-bare-value.ww"), "undefined: base");
	testenv.writefile(strings.concat(td, "/transitive-bare-type.ww"),
		strings.concat("package main;\nimport left;\n",
		"fn main() i32 = { let x: token; return 0; };\n"));
	rejectstable(td, "transitive-bare-type",
		strings.concat(td, "/transitive-bare-type.ww"),
		"unknown type 'token'");
	// Keep the helper's main directory live so the graph also has a normal
	// successful consumer in this fixture tree.
	assert(testenv.exists(main));
	testenv.clean(td);
};

@test fn import_diagnostics() void = {
	let td: str = testenv.fresh();
	let missing: str = strings.concat(td, "/missing"); mkdir(missing);
	testenv.writefile(strings.concat(missing, "/main.ww"), strings.concat(
		"package main;\nimport nowhere;\n",
		"fn main() i32 = { return 0; };\n"));
	rejectstable(td, "missing", missing, "cannot find package nowhere");

	let self: str = strings.concat(td, "/self"); mkdir(self);
	testenv.writefile(strings.concat(self, "/main.ww"), strings.concat(
		"package main;\nimport self;\n",
		"fn main() i32 = { return 0; };\n"));
	rejectstable(td, "self", self, "self-import");

	let malformed: str = strings.concat(td, "/malformed"); mkdir(malformed);
	testenv.writefile(strings.concat(malformed, "/main.ww"), strings.concat(
		"package main;\nimport ;\n",
		"fn main() i32 = { return 0; };\n"));
	rejectstable(td, "malformed", malformed,
		"main.ww:2:8: error: expected identifier");

	let attributed: str = strings.concat(td, "/attributed"); mkdir(attributed);
	testenv.writefile(strings.concat(attributed, "/main.ww"), strings.concat(
		"package main;\n@trace import nowhere;\n",
		"fn main() i32 = { return 0; };\n"));
	rejectstable(td, "attributed", attributed,
		"import cannot be exported or attributed");

	let exported: str = strings.concat(td, "/exported"); mkdir(exported);
	testenv.writefile(strings.concat(exported, "/main.ww"), strings.concat(
		"package main;\nexport import nowhere;\n",
		"fn main() i32 = { return 0; };\n"));
	rejectstable(td, "exported", exported,
		"main.ww:2:8: error: import cannot be exported or attributed");

	let conflict: str = strings.concat(td, "/conflict"); mkdir(conflict);
	testenv.writefile(strings.concat(conflict, "/a.ww"),
		"package main;\nfn main() i32 = { return 0; };\n");
	testenv.writefile(strings.concat(conflict, "/z.ww"),
		"package other;\nfn spare() void = { };\n");
	rejectstable(td, "conflict", conflict, "conflicting package names");

	let real: str = strings.concat(td, "/real"); mkdir(real);
	testenv.writefile(strings.concat(real, "/real.ww"), strings.concat(
		"package real;\n",
		"export fn value() i32 = { return 1; };\n"));
	let alias: str = strings.concat(td, "/alias");
	assert(os.symlink(real, alias) == 0);
	let aliasmain: str = strings.concat(td, "/alias-main"); mkdir(aliasmain);
	testenv.writefile(strings.concat(aliasmain, "/main.ww"), strings.concat(
		"package main;\nimport real;\nimport alias;\n",
		"fn main() i32 = { return 0; };\n"));
	rejectstable(td, "identity-alias", aliasmain, "identities");
	testenv.clean(td);
};

@test fn package_artifact_identity_and_flag_contract() void = {
	let td: str = testenv.fresh();
	let root: str = strings.concat(td, "/root"); mkdir(root);
	let foo: str = strings.concat(root, "/foo"); mkdir(foo);
	let bar: str = strings.concat(foo, "/bar"); mkdir(bar);
	testenv.writefile(strings.concat(bar, "/bar.ww"), strings.concat(
		"package bar;\n",
		"export fn nestedvalue() i32 = { return 41; };\n"));
	let ca: str = strings.concat(td, "/nested-c.a");
	let wa: str = strings.concat(td, "/nested-w.a");
	let cav: []str = [testenv.driver("ww"), "build", "-p", "-I", root,
		"-o", ca, "foo.bar"];
	let wav: []str = [testenv.driver("ww_ww"), "build", "-p", "-I", root,
		"-o", wa, "foo.bar"];
	if (code(td, "nested_package_c", cav) != 0
	    || code(td, "nested_package_w", wav) != 0) {
		fail("package-identity", "nested logical package build failed");
	};
	if (!testenv.same(testenv.readfile(ca), testenv.readfile(wa))
	    || !testenv.same(testenv.readfile(strings.concat(ca, ".wwi")),
		testenv.readfile(strings.concat(wa, ".wwi")))) {
		fail("package-identity", "nested C/WW package products differ");
	};
	let nestedasm: str = testenv.readfile(strings.concat(ca,
		".sepwork/foo.bar.s"));
	if (!testenv.has(nestedasm, "foo.bar.nestedvalue")) {
		fail("package-identity", "archive lost the full logical import path");
	};

	let drivers: []str = ["ww", "ww_ww"];
	let i: i32 = 0;
	for (i < drivers.len) {
		let badout: str = strings.concat(td, "/bad-flags-", drivers[i]);
		let av: []str = [testenv.driver(drivers[i]), "build", "-p", "-S",
			"-I", root, "-o", badout, "foo.bar"];
		let co: testenv.commandout;
		command(td, strings.concat("package_flag_contract_", drivers[i]),
			av, &co);
		if (co.termination != exec.termination.EXIT || co.code == 0
		    || !testenv.has(co.stderr,
			"ww build: -p and -S cannot be combined")) {
			fail("package-flags", strings.concat(drivers[i],
				" accepted -p -S"));
		};
		i += 1;
	};
	testenv.clean(td);
};

@test fn generated_test_hook_is_not_a_user_exemption() void = {
	let td: str = testenv.fresh();
	let src: str = strings.concat(td, "/case.ww");
	testenv.writefile(src, strings.concat(
		"package probe;\nimport test;\n",
		"fn bad() void = { test.run(); };\n",
		"@test fn one() void = {};\n"));
	let compilers: []str = ["w6c", "w6c_ww"];
	let i: i32 = 0;
	for (i < compilers.len) {
		let asm: str = strings.concat(td, "/case-", compilers[i], ".s");
		let av: []str = [testenv.driver(compilers[i]), "-T", "-c", "-o",
			asm, src];
		let co: testenv.commandout;
		command(td, strings.concat("test_hook_", compilers[i]), av, &co);
		if (co.termination != exec.termination.EXIT || co.code == 0
		    || !testenv.has(co.stderr,
			"package 'test' has no exported declaration 'run'")) {
			fail("test-hook", strings.concat(compilers[i],
				" exempted a user-authored test.run"));
		};
		i += 1;
	};
	testenv.clean(td);
};

fn writecyclepkg(td: str, name: str, next: str) void = {
	let dir: str = strings.concat(td, "/", name); mkdir(dir);
	testenv.writefile(strings.concat(dir, "/p.ww"), strings.concat(
		"package ", name, ";\nimport ", next, ";\n",
		"export fn value() i32 = { return 1; };\n"));
};

@test fn cycle_diagnostics() void = {
	let td: str = testenv.fresh();
	let two: str = strings.concat(td, "/two-main"); mkdir(two);
	testenv.writefile(strings.concat(two, "/main.ww"),
		"package main;\nimport aa;\nfn main() i32 = { return 0; };\n");
	writecyclepkg(td, "aa", "bb");
	writecyclepkg(td, "bb", "aa");
	rejectstable(td, "cycle-two", two,
		"dependency cycle: aa -> bb -> aa");
	rejectstable(td, "cycle-root", strings.concat(td, "/aa"),
		"dependency cycle: aa -> bb -> aa");

	// A second isolated root set avoids reusing the two-package graph.
	let longroot: str = strings.concat(td, "/long-main"); mkdir(longroot);
	testenv.writefile(strings.concat(longroot, "/main.ww"),
		"package main;\nimport ca;\nfn main() i32 = { return 0; };\n");
	writecyclepkg(td, "ca", "cb");
	writecyclepkg(td, "cb", "cc");
	writecyclepkg(td, "cc", "ca");
	rejectstable(td, "cycle-long", longroot,
		"dependency cycle: ca -> cb -> cc -> ca");
	testenv.clean(td);
};