authorgravatar for topolarity@tapscott.meCody Tapscott <topolarity@tapscott.me> 2022-03-02 23:21:55-07:00
committergravatar for topolarity@tapscott.meCody Tapscott <topolarity@tapscott.me> 2022-03-03 14:31:49-07:00
logade2d0c6a28009ac505b4863079ede3ba64fcdd1
tree9a6a203309c5a601fe6067bf7e8e442822066a45
parent58f961f4cb9875bbce3070969438ecf08f392c9f

stdlib WASI: Add realpath() support for non-absolute Preopens

8 files changed, 95 insertions(+), 75 deletions(-)

lib/std/build.zig-2
......@@ -2707,8 +2707,6 @@ pub const LibExeObjStep = struct {
27072707 try zig_args.append("--test-cmd");
27082708 try zig_args.append("--dir=.");
27092709 try zig_args.append("--test-cmd");
2710 try zig_args.append("--mapdir=/cwd::.");
2711 try zig_args.append("--test-cmd");
27122710 try zig_args.append("--allow-unknown-exports"); // TODO: Remove when stage2 is default compiler
27132711 try zig_args.append("--test-cmd-bin");
27142712 } else {
lib/std/fs/path.zig+4-4
......@@ -735,7 +735,7 @@ pub fn resolvePosix(allocator: Allocator, paths: []const []const u8) ![]u8 {
735735
736736test "resolve" {
737737 if (native_os == .wasi and builtin.link_libc) return error.SkipZigTest;
738 if (native_os == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, "/cwd");
738 if (native_os == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, ".");
739739
740740 const cwd = try process.getCwdAlloc(testing.allocator);
741741 defer testing.allocator.free(cwd);
......@@ -756,7 +756,7 @@ test "resolveWindows" {
756756 return error.SkipZigTest;
757757 }
758758 if (native_os == .wasi and builtin.link_libc) return error.SkipZigTest;
759 if (native_os == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, "/cwd");
759 if (native_os == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, ".");
760760 if (native_os == .windows) {
761761 const cwd = try process.getCwdAlloc(testing.allocator);
762762 defer testing.allocator.free(cwd);
......@@ -802,7 +802,7 @@ test "resolveWindows" {
802802
803803test "resolvePosix" {
804804 if (native_os == .wasi and builtin.link_libc) return error.SkipZigTest;
805 if (native_os == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, "/cwd");
805 if (native_os == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, ".");
806806
807807 try testResolvePosix(&[_][]const u8{ "/a/b", "c" }, "/a/b/c");
808808 try testResolvePosix(&[_][]const u8{ "/a/b", "c", "//d", "e///" }, "/d/e");
......@@ -1216,7 +1216,7 @@ test "relative" {
12161216 return error.SkipZigTest;
12171217 }
12181218 if (native_os == .wasi and builtin.link_libc) return error.SkipZigTest;
1219 if (native_os == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, "/cwd");
1219 if (native_os == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, ".");
12201220
12211221 try testRelativeWindows("c:/blah\\blah", "d:/games", "D:\\games");
12221222 try testRelativeWindows("c:/aaaa/bbbb", "c:/aaaa", "..");
lib/std/fs/test.zig+7-7
......@@ -47,7 +47,7 @@ fn testReadLink(dir: Dir, target_path: []const u8, symlink_path: []const u8) !vo
4747
4848test "accessAbsolute" {
4949 if (builtin.os.tag == .wasi and builtin.link_libc) return error.SkipZigTest;
50 if (builtin.os.tag == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, "/cwd");
50 if (builtin.os.tag == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, ".");
5151
5252 var tmp = tmpDir(.{});
5353 defer tmp.cleanup();
......@@ -66,7 +66,7 @@ test "accessAbsolute" {
6666
6767test "openDirAbsolute" {
6868 if (builtin.os.tag == .wasi and builtin.link_libc) return error.SkipZigTest;
69 if (builtin.os.tag == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, "/cwd");
69 if (builtin.os.tag == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, ".");
7070
7171 var tmp = tmpDir(.{});
7272 defer tmp.cleanup();
......@@ -103,7 +103,7 @@ test "openDir cwd parent .." {
103103
104104test "readLinkAbsolute" {
105105 if (builtin.os.tag == .wasi and builtin.link_libc) return error.SkipZigTest;
106 if (builtin.os.tag == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, "/cwd");
106 if (builtin.os.tag == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, ".");
107107
108108 var tmp = tmpDir(.{});
109109 defer tmp.cleanup();
......@@ -512,7 +512,7 @@ test "rename" {
512512
513513test "renameAbsolute" {
514514 if (builtin.os.tag == .wasi and builtin.link_libc) return error.SkipZigTest;
515 if (builtin.os.tag == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, "/cwd");
515 if (builtin.os.tag == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, ".");
516516
517517 var tmp_dir = tmpDir(.{});
518518 defer tmp_dir.cleanup();
......@@ -947,7 +947,7 @@ test "open file with exclusive nonblocking lock twice (absolute paths)" {
947947
948948test "walker" {
949949 if (builtin.os.tag == .wasi and builtin.link_libc) return error.SkipZigTest;
950 if (builtin.os.tag == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, "/cwd");
950 if (builtin.os.tag == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, ".");
951951
952952 var tmp = tmpDir(.{ .iterate = true });
953953 defer tmp.cleanup();
......@@ -998,7 +998,7 @@ test "walker" {
998998
999999test ". and .. in fs.Dir functions" {
10001000 if (builtin.os.tag == .wasi and builtin.link_libc) return error.SkipZigTest;
1001 if (builtin.os.tag == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, "/cwd");
1001 if (builtin.os.tag == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, ".");
10021002
10031003 var tmp = tmpDir(.{});
10041004 defer tmp.cleanup();
......@@ -1027,7 +1027,7 @@ test ". and .. in fs.Dir functions" {
10271027
10281028test ". and .. in absolute functions" {
10291029 if (builtin.os.tag == .wasi and builtin.link_libc) return error.SkipZigTest;
1030 if (builtin.os.tag == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, "/cwd");
1030 if (builtin.os.tag == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, ".");
10311031
10321032 var tmp = tmpDir(.{});
10331033 defer tmp.cleanup();
lib/std/fs/wasi.zig+13-2
......@@ -194,6 +194,17 @@ pub const PreopenList = struct {
194194 return null;
195195 }
196196
197 /// Find preopen by fd. If the preopen exists, return it.
198 /// Otherwise, return `null`.
199 pub fn findByFd(self: Self, fd: fd_t) ?Preopen {
200 for (self.buffer.items) |preopen| {
201 if (preopen.fd == fd) {
202 return preopen;
203 }
204 }
205 return null;
206 }
207
197208 /// Find preopen by type. If the preopen exists, return it.
198209 /// Otherwise, return `null`.
199210 pub fn find(self: Self, preopen_type: PreopenType) ?*const Preopen {
......@@ -224,6 +235,6 @@ test "extracting WASI preopens" {
224235
225236 try preopens.populate();
226237
227 const preopen = preopens.find(PreopenType{ .Dir = "/cwd" }) orelse unreachable;
228 try std.testing.expect(preopen.@"type".eql(PreopenType{ .Dir = "/cwd" }));
238 const preopen = preopens.find(PreopenType{ .Dir = "." }) orelse unreachable;
239 try std.testing.expect(preopen.@"type".eql(PreopenType{ .Dir = "." }));
229240}
lib/std/os.zig+62-50
......@@ -1431,6 +1431,8 @@ var wasi_cwd = if (builtin.os.tag == .wasi and !builtin.link_libc) struct {
14311431}{} else undefined;
14321432
14331433/// Initialize the available Preopen list on WASI and set the CWD to `cwd_init`.
1434/// Note that `cwd_init` corresponds to a Preopen directory, not necessarily
1435/// a POSIX path. For example, "." matches a Preopen provided with `--dir=.`
14341436///
14351437/// This must be called before using any relative or absolute paths with `std.os`
14361438/// functions, if you are on WASI without linking libc.
......@@ -1482,8 +1484,22 @@ fn resolvePathAndGetWasiPreopen(path: []const u8, preopen: ?*?Preopen, out_buffe
14821484 if (wasi_cwd.preopens == null) @panic("On WASI, `initPreopensWasi` must be called to initialize preopens " ++
14831485 "before using any CWD-relative or absolute paths.\n");
14841486
1485 // If the path is absolute, we need to lookup a containing Preopen
1486 const abs_path = std.fs.path.resolve(alloc, &.{ "/", path }) catch return error.NameTooLong;
1487 if (mem.startsWith(u8, path, "/preopens/fd/")) {
1488 // "/preopens/fd/<N>" is a special prefix, which refers to a Preopen directly by fd
1489 const fd_start = "/preopens/fd/".len;
1490 const fd_end = mem.indexOfScalarPos(u8, path, fd_start, '/') orelse path.len;
1491 const fd = std.fmt.parseUnsigned(fd_t, path[fd_start..fd_end], 10) catch unreachable;
1492 const rel_path = if (path.len > fd_end + 1) path[fd_end + 1 ..] else ".";
1493
1494 if (preopen) |p| p.* = wasi_cwd.preopens.?.findByFd(fd);
1495 return RelativePath{
1496 .dir_fd = fd,
1497 .relative_path = alloc.dupe(u8, rel_path) catch return error.NameTooLong,
1498 };
1499 }
1500
1501 // For any other absolute path, we need to lookup a containing Preopen
1502 const abs_path = fs.path.resolve(alloc, &.{ "/", path }) catch return error.NameTooLong;
14871503 const preopen_uri = wasi_cwd.preopens.?.findContaining(.{ .Dir = abs_path });
14881504
14891505 if (preopen_uri) |po| {
......@@ -1507,7 +1523,7 @@ fn resolvePathAndGetWasiPreopen(path: []const u8, preopen: ?*?Preopen, out_buffe
15071523 // First resolve a combined path, where the "/" corresponds to `cwd.dir_fd`
15081524 // not the true filesystem root
15091525 const paths = &.{ "/", cwd.relative_path, path };
1510 const resolved_path = std.fs.path.resolve(alloc, paths) catch return error.NameTooLong;
1526 const resolved_path = fs.path.resolve(alloc, paths) catch return error.NameTooLong;
15111527
15121528 // Strip off the fake root to get the relative path w.r.t. `cwd.dir_fd`
15131529 const resolved_relative_path = resolved_path[1..];
......@@ -1956,28 +1972,14 @@ pub fn getcwd(out_buffer: []u8) GetCwdError![]u8 {
19561972 if (builtin.os.tag == .windows) {
19571973 return windows.GetCurrentDirectory(out_buffer);
19581974 } else if (builtin.os.tag == .wasi and !builtin.link_libc) {
1959 var allocator = std.heap.FixedBufferAllocator.init(out_buffer);
1960 var alloc = allocator.allocator();
1961 if (wasi_cwd.cwd) |cwd| {
1962 if (wasi_cwd.cwd_preopen) |po| {
1963 var base_cwd_dir = switch (po.@"type") {
1964 .Dir => |dir| dir,
1965 };
1966 if (!fs.path.isAbsolute(base_cwd_dir)) {
1967 // This preopen is not based on an absolute path, so we have
1968 // no way to know the absolute path of the CWD
1969 return error.CurrentWorkingDirectoryUnlinked;
1970 }
1971 const paths = &.{ base_cwd_dir, cwd.relative_path };
1972 return std.fs.path.resolve(alloc, paths) catch return error.NameTooLong;
1973 } else {
1974 // The CWD is not rooted to an existing Preopen,
1975 // so we have no way to know its absolute path
1976 return error.CurrentWorkingDirectoryUnlinked;
1977 }
1978 } else {
1979 return alloc.dupe(u8, "/") catch return error.NameTooLong;
1980 }
1975 var buf: [MAX_PATH_BYTES]u8 = undefined;
1976 const path = realpathWasi(".", &buf) catch |err| switch (err) {
1977 error.NameTooLong => return error.NameTooLong,
1978 error.InvalidHandle => return error.CurrentWorkingDirectoryUnlinked,
1979 };
1980 if (out_buffer.len < path.len) return error.NameTooLong;
1981 std.mem.copy(u8, out_buffer, path);
1982 return out_buffer[0..path.len];
19811983 }
19821984
19831985 const err = if (builtin.link_libc) blk: {
......@@ -5089,35 +5091,45 @@ pub fn realpath(pathname: []const u8, out_buffer: *[MAX_PATH_BYTES]u8) RealPathE
50895091 const pathname_w = try windows.sliceToPrefixedFileW(pathname);
50905092 return realpathW(pathname_w.span(), out_buffer);
50915093 } else if (builtin.os.tag == .wasi and !builtin.link_libc) {
5092 // NOTE: This emulation is incomplete. Symbolic links are not
5093 // currently expanded during path canonicalization.
5094 var alloc = std.heap.FixedBufferAllocator.init(out_buffer);
5095 if (fs.path.isAbsolute(pathname))
5096 return try fs.path.resolve(alloc.allocator(), &.{pathname}) catch error.NameTooLong;
5097 if (wasi_cwd.cwd) |cwd| {
5098 if (wasi_cwd.cwd_preopen) |po| {
5099 var base_cwd_dir = switch (po.@"type") {
5100 .Dir => |dir| dir,
5101 };
5102 if (!fs.path.isAbsolute(base_cwd_dir)) {
5103 // This preopen is not based on an absolute path, so we have
5104 // no way to know the absolute path of the CWD
5105 return error.InvalidHandle;
5106 }
5094 return realpathWasi(pathname, out_buffer);
5095 }
5096 const pathname_c = try toPosixPath(pathname);
5097 return realpathZ(&pathname_c, out_buffer);
5098}
51075099
5108 const paths = &.{ base_cwd_dir, cwd.relative_path, pathname };
5109 return fs.path.resolve(alloc.allocator(), paths) catch error.NameTooLong;
5110 } else {
5111 // The CWD is not rooted to an existing Preopen,
5112 // so we have no way to know its absolute path
5113 return error.InvalidHandle;
5114 }
5100/// Return an emulated canonicalized absolute pathname on WASI.
5101///
5102/// NOTE: This emulation is incomplete. Symbolic links are not
5103/// currently expanded during path canonicalization.
5104fn realpathWasi(pathname: []const u8, out_buffer: []u8) ![]u8 {
5105 var alloc = std.heap.FixedBufferAllocator.init(out_buffer);
5106 if (fs.path.isAbsolute(pathname))
5107 return try fs.path.resolve(alloc.allocator(), &.{pathname}) catch error.NameTooLong;
5108 if (wasi_cwd.cwd) |cwd| {
5109 if (wasi_cwd.cwd_preopen) |po| {
5110 var base_cwd_dir = switch (po.@"type") {
5111 .Dir => |dir| dir,
5112 };
5113 const paths: [][]const u8 = if (fs.path.isAbsolute(base_cwd_dir)) blk: {
5114 break :blk &.{ base_cwd_dir, cwd.relative_path, pathname };
5115 } else blk: {
5116 // No absolute path is associated with this preopen, so
5117 // instead we use a special "/preopens/fd/<N>/" prefix
5118 var buf: [16]u8 = undefined;
5119 var fbs = std.io.fixedBufferStream(&buf);
5120 std.fmt.formatInt(po.fd, 10, .lower, .{}, fbs.writer()) catch return error.NameTooLong;
5121 break :blk &.{ "/preopens/fd/", fbs.getWritten(), cwd.relative_path, pathname };
5122 };
5123
5124 return fs.path.resolve(alloc.allocator(), paths) catch error.NameTooLong;
51155125 } else {
5116 return try fs.path.resolve(alloc.allocator(), &.{ "/", pathname }) catch error.NameTooLong;
5126 // The CWD is not rooted to an existing Preopen,
5127 // so we have no way to know its absolute path
5128 return error.InvalidHandle;
51175129 }
5130 } else {
5131 return try fs.path.resolve(alloc.allocator(), &.{ "/", pathname }) catch error.NameTooLong;
51185132 }
5119 const pathname_c = try toPosixPath(pathname);
5120 return realpathZ(&pathname_c, out_buffer);
51215133}
51225134
51235135/// Same as `realpath` except `pathname` is null-terminated.
lib/std/os/test.zig+7-7
......@@ -49,7 +49,7 @@ test "chdir smoke test" {
4949
5050test "open smoke test" {
5151 if (native_os == .wasi and builtin.link_libc) return error.SkipZigTest;
52 if (native_os == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, "/cwd");
52 if (native_os == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, ".");
5353
5454 // TODO verify file attributes using `fstat`
5555
......@@ -104,7 +104,7 @@ test "open smoke test" {
104104
105105test "openat smoke test" {
106106 if (native_os == .wasi and builtin.link_libc) return error.SkipZigTest;
107 if (native_os == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, "/cwd");
107 if (native_os == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, ".");
108108
109109 // TODO verify file attributes using `fstatat`
110110
......@@ -141,7 +141,7 @@ test "openat smoke test" {
141141
142142test "symlink with relative paths" {
143143 if (native_os == .wasi and builtin.link_libc) return error.SkipZigTest;
144 if (native_os == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, "/cwd");
144 if (native_os == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, ".");
145145
146146 const cwd = fs.cwd();
147147 cwd.deleteFile("file.txt") catch {};
......@@ -197,7 +197,7 @@ test "link with relative paths" {
197197 if (builtin.link_libc) {
198198 return error.SkipZigTest;
199199 } else {
200 try os.initPreopensWasi(std.heap.page_allocator, "/cwd");
200 try os.initPreopensWasi(std.heap.page_allocator, ".");
201201 }
202202 },
203203 .linux, .solaris => {},
......@@ -237,7 +237,7 @@ test "link with relative paths" {
237237
238238test "linkat with different directories" {
239239 switch (native_os) {
240 .wasi => if (!builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, "/cwd"),
240 .wasi => if (!builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, "."),
241241 .linux, .solaris => {},
242242 else => return error.SkipZigTest,
243243 }
......@@ -890,7 +890,7 @@ test "POSIX file locking with fcntl" {
890890
891891test "rename smoke test" {
892892 if (native_os == .wasi and builtin.link_libc) return error.SkipZigTest;
893 if (native_os == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, "/cwd");
893 if (native_os == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, ".");
894894
895895 var tmp = tmpDir(.{});
896896 defer tmp.cleanup();
......@@ -947,7 +947,7 @@ test "rename smoke test" {
947947
948948test "access smoke test" {
949949 if (native_os == .wasi and builtin.link_libc) return error.SkipZigTest;
950 if (native_os == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, "/cwd");
950 if (native_os == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, ".");
951951
952952 var tmp = tmpDir(.{});
953953 defer tmp.cleanup();
lib/std/testing.zig+2-2
......@@ -327,8 +327,8 @@ fn getCwdOrWasiPreopen() std.fs.Dir {
327327 defer preopens.deinit();
328328 preopens.populate() catch
329329 @panic("unable to make tmp dir for testing: unable to populate preopens");
330 const preopen = preopens.find(std.fs.wasi.PreopenType{ .Dir = "/cwd" }) orelse
331 @panic("unable to make tmp dir for testing: didn't find '/cwd' in the preopens");
330 const preopen = preopens.find(std.fs.wasi.PreopenType{ .Dir = "." }) orelse
331 @panic("unable to make tmp dir for testing: didn't find '.' in the preopens");
332332
333333 return std.fs.Dir{ .fd = preopen.fd };
334334 } else {
src/test.zig-1
......@@ -1188,7 +1188,6 @@ pub const TestContext = struct {
11881188 .wasmtime => |wasmtime_bin_name| if (enable_wasmtime) {
11891189 try argv.append(wasmtime_bin_name);
11901190 try argv.append("--dir=.");
1191 try argv.append("--mapdir=/cwd::.");
11921191 try argv.append(exe_path);
11931192 } else {
11941193 return; // wasmtime not available; pass test.