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stage2: Move WASI/Zig-specific selfExePath to introspect.zig

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This commit is contained in:
Cody Tapscott
2022-04-18 23:06:49 -07:00
parent edb4a07d4d
commit bb9cd6db1c
4 changed files with 42 additions and 51 deletions
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46
lib/std/fs.zig
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@@ -2547,15 +2547,6 @@ pub const SelfExePathError = os.ReadLinkError || os.SysCtlError || os.RealPathEr
/// `selfExePath` except allocates the result on the heap.
/// Caller owns returned memory.
pub fn selfExePathAlloc(allocator: Allocator) ![]u8 {
if (builtin.os.tag == .wasi) {
var args = try std.process.argsWithAllocator(allocator);
defer args.deinit();
// On WASI, argv[0] is always just the basename of the current executable
const exe_name = args.next() orelse return error.FileNotFound;
var buf: [MAX_PATH_BYTES]u8 = undefined;
return allocator.dupe(u8, try selfExePathWasi(&buf, exe_name));
}
// Use of MAX_PATH_BYTES here is justified as, at least on one tested Linux
// system, readlink will completely fail to return a result larger than
// PATH_MAX even if given a sufficiently large buffer. This makes it
@@ -2657,43 +2648,6 @@ pub fn selfExePath(out_buffer: []u8) SelfExePathError![]u8 {
}
}
/// WASI-specific implementation of selfExePath
///
/// On WASI argv0 is always just the executable basename, so this function relies
/// using a fixed executable directory path: "/zig"
///
/// This path can be configured in wasmtime using `--mapdir=/zig::/path/to/zig/dir/`
fn selfExePathWasi(out_buffer: []u8, argv0: []const u8) SelfExePathError![]const u8 {
var allocator = std.heap.FixedBufferAllocator.init(out_buffer);
var alloc = allocator.allocator();
// Check these paths:
// 1. "/zig/{exe_name}"
// 2. "/zig/bin/{exe_name}"
const base_paths_to_check = &[_][]const u8{ "/zig", "/zig/bin" };
const exe_names_to_check = &[_][]const u8{ path.basename(argv0), "zig.wasm" };
for (base_paths_to_check) |base_path| {
for (exe_names_to_check) |exe_name| {
const test_path = path.join(alloc, &.{ base_path, exe_name }) catch continue;
// Make sure it's a file we're pointing to
const file = os.fstatat(os.wasi.AT.FDCWD, test_path, 0) catch continue;
if (file.filetype != .REGULAR_FILE) continue;
// Path seems to be valid, let's try to turn it into an absolute path
var real_path_buf: [MAX_PATH_BYTES]u8 = undefined;
if (os.realpath(test_path, &real_path_buf)) |real_path| {
if (real_path.len > out_buffer.len)
return error.NameTooLong;
mem.copy(u8, out_buffer, real_path);
return out_buffer[0..real_path.len];
} else |_| continue;
}
}
return error.FileNotFound;
}
/// The result is UTF16LE-encoded.
pub fn selfExePathW() [:0]const u16 {
const image_path_name = &os.windows.peb().ProcessParameters.ImagePathName;