Commit 02f5d2673f1bb21e7329acdd664fed565ecd4317 | zig

author	Andrew Kelley <andrew@ziglang.org> 2023-02-19 09:40:25-07:00
committer	Andrew Kelley <andrew@ziglang.org> 2023-02-19 09:40:55-07:00
log	02f5d2673f1bb21e7329acdd664fed565ecd4317
tree	b2499481c929ba1497d6eef8b85cc46205f953ab
parent	772a0eb68ac95b7e24508580499b49872fdb541f

Revert "Merge pull request #14661 from evacchi/zig-wasi-preopens"

This reverts commit 772a0eb68ac95b7e24508580499b49872fdb541f, reversing
changes made to 0bb178bbb2451238a326c6e916ecf38fbc34cab1.

This needs a rebase against master branch - it has build-breaking merge
conflicts. I also added a "changes requested" review on the original
pull request.

3 files changed, 1 insertions(+), 116 deletions(-)

lib
- std
  - Build
    CompileStep.zig
  - fs
    test.zig
    wasi.zig

lib/std/Build/CompileStep.zig+1-3

 @@ -1555,9 +1555,7 @@ fn make(step: *Step) !void {
                     try zig_args.append("--test-cmd");
                     try zig_args.append(bin_name);
                     try zig_args.append("--test-cmd");
-                    try zig_args.append("--mapdir=/::.");
+                    try zig_args.append("--dir=.");
-                    try zig_args.append("--test-cmd");
-                    try zig_args.append("--mapdir=/tmp::/tmp");
                     try zig_args.append("--test-cmd-bin");
                 } else {
                     try zig_args.append("--test-no-exec");

lib/std/fs/test.zig-5

 @@ -13,11 +13,6 @@ const File = std.fs.File;
 const tmpDir = testing.tmpDir;
 const tmpIterableDir = testing.tmpIterableDir;
-// ensure tests for fs/wasi.zig are run
-comptime {
-    _ = std.fs.wasi;
-}
 test "Dir.readLink" {
     var tmp = tmpDir(.{});
     defer tmp.cleanup();

lib/std/fs/wasi.zig-108

...	@@ -9,7 +9,6 @@ const Allocator = mem.Allocator;	...	@@ -9,7 +9,6 @@ const Allocator = mem.Allocator;
9	const wasi = std.os.wasi;	9	const wasi = std.os.wasi;
10	const fd_t = wasi.fd_t;	10	const fd_t = wasi.fd_t;
11	const prestat_t = wasi.prestat_t;	11	const prestat_t = wasi.prestat_t;
12	const testing = std.testing;
13		12
14	pub const Preopens = struct {	13	pub const Preopens = struct {
15	// Indexed by file descriptor number.	14	// Indexed by file descriptor number.
...	@@ -23,30 +22,6 @@ pub const Preopens = struct {	...	@@ -23,30 +22,6 @@ pub const Preopens = struct {
23	}	22	}
24	return null;	23	return null;
25	}	24	}
26
27	pub fn findDir(p: Preopens, full_path: []const u8, flags: std.fs.Dir.OpenDirOptions) std.fs.Dir.OpenError!std.fs.Dir {
28	if (p.names.len <= 2)
29	return std.fs.Dir.OpenError.BadPathName; // there are no preopens
30
31	var prefix: []const u8 = "";
32	var fd: usize = 0;
33	for (p.names) \|preopen, i\| {
34	if (i > 2 and wasiPathPrefixMatches(preopen, full_path)) {
35	if (preopen.len > prefix.len) {
36	prefix = preopen;
37	fd = i;
38	}
39	}
40	}
41
42	// still no match
43	if (fd == 0) {
44	return std.fs.Dir.OpenError.FileNotFound;
45	}
46	const d = std.fs.Dir{ .fd = @intCast(os.fd_t, fd) };
47	const rel = full_path[prefix.len + 1 .. full_path.len];
48	return d.openDirWasi(rel, flags);
49	}
50	};	25	};
51		26
52	pub fn preopensAlloc(gpa: Allocator) Allocator.Error!Preopens {	27	pub fn preopensAlloc(gpa: Allocator) Allocator.Error!Preopens {
...	@@ -79,86 +54,3 @@ pub fn preopensAlloc(gpa: Allocator) Allocator.Error!Preopens {	...	@@ -79,86 +54,3 @@ pub fn preopensAlloc(gpa: Allocator) Allocator.Error!Preopens {
79	names.appendAssumeCapacity(name);	54	names.appendAssumeCapacity(name);
80	}	55	}
81	}	56	}
82
83	fn wasiPathPrefixMatches(prefix: []const u8, path: []const u8) bool {
84	if (path[0] != '/' and prefix.len == 0)
85	return true;
86
87	if (path.len < prefix.len)
88	return false;
89
90	if (prefix.len == 1) {
91	return prefix[0] == path[0];
92	}
93
94	if (!std.mem.eql(u8, path[0..prefix.len], prefix)) {
95	return false;
96	}
97
98	return path.len == prefix.len or
99	path[prefix.len] == '/';
100	}
101
102	test "preopens" {
103	if (builtin.os.tag != .wasi or builtin.link_libc) return error.SkipZigTest;
104
105	// lifted from `testing`
106	const random_bytes_count = 12;
107	const buf_size = 256;
108	const path = "/tmp";
109	const tmp_file_name = "file.txt";
110	const nonsense = "nonsense";
111
112	var random_bytes: [random_bytes_count]u8 = undefined;
113	var buf: [buf_size]u8 = undefined;
114
115	std.crypto.random.bytes(&random_bytes);
116	const sub_path = std.fs.base64_encoder.encode(&buf, &random_bytes);
117
118	// find all preopens
119	const allocator = std.heap.page_allocator;
120	var wasi_preopens = try std.fs.wasi.preopensAlloc(allocator);
121
122	// look for the exact "/tmp" preopen match
123	const fd = std.fs.wasi.Preopens.find(wasi_preopens, path) orelse unreachable;
124	const base_dir = std.fs.Dir{ .fd = fd };
125
126	var tmp_path = base_dir.makeOpenPath(sub_path, .{}) catch
127	@panic("unable to make tmp dir for testing: /tmp/<rand-path>");
128
129	defer tmp_path.close();
130	defer tmp_path.deleteTree(sub_path) catch {};
131
132	// create a file under /tmp/<rand>/file.txt with contents "nonsense"
133	try tmp_path.writeFile(tmp_file_name, nonsense);
134
135	// now look for the file as a single path
136	var tmp_dir_path_buf: [buf_size]u8 = undefined;
137	const tmp_dir_path = try std.fmt.bufPrint(&tmp_dir_path_buf, "{s}/{s}", .{ path, sub_path });
138
139	// find "/tmp/<rand>" using `findDir()`
140	const tmp_file_dir = try wasi_preopens.findDir(tmp_dir_path, .{});
141
142	const text = try tmp_file_dir.readFile(tmp_file_name, &buf);
143
144	// ensure the file contents match "nonsense"
145	try testing.expect(std.mem.eql(u8, nonsense, text));
146	}
147
148	test "wasiPathPrefixMatches" {
149	try testing.expect(wasiPathPrefixMatches("/", "/foo"));
150	try testing.expect(wasiPathPrefixMatches("/testcases", "/testcases/test.txt"));
151	try testing.expect(wasiPathPrefixMatches("", "foo"));
152	try testing.expect(wasiPathPrefixMatches("foo", "foo"));
153	try testing.expect(wasiPathPrefixMatches("foo", "foo/bar"));
154	try testing.expect(!wasiPathPrefixMatches("bar", "foo/bar"));
155	try testing.expect(!wasiPathPrefixMatches("bar", "foo"));
156	try testing.expect(wasiPathPrefixMatches("foo", "foo/bar"));
157	try testing.expect(!wasiPathPrefixMatches("fooo", "foo"));
158	try testing.expect(!wasiPathPrefixMatches("foo", "fooo"));
159	try testing.expect(!wasiPathPrefixMatches("foo/bar", "foo"));
160	try testing.expect(!wasiPathPrefixMatches("bar/foo", "foo"));
161	try testing.expect(wasiPathPrefixMatches("/foo", "/foo"));
162	try testing.expect(wasiPathPrefixMatches("/foo", "/foo"));
163	try testing.expect(wasiPathPrefixMatches("/foo", "/foo/"));
164	}