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std.ChildProcess.spawn has a consistent error set
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across targets. Also fix detection of pkg-config not
installed on Windows when using zig build.
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@andrewrk
andrewrk committed Nov 10, 2019
1 parent 891e214 commit d44a696
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Showing 2 changed files with 78 additions and 18 deletions.
1 change: 1 addition & 0 deletions lib/std/build.zig
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Original file line number Diff line number Diff line change
Expand Up @@ -957,6 +957,7 @@ pub const Builder = struct {
error.ProcessTerminated => error.PkgConfigCrashed,
error.ExitCodeFailure => error.PkgConfigFailed,
error.FileNotFound => error.PkgConfigNotInstalled,
error.InvalidName => error.PkgConfigNotInstalled,
error.PkgConfigInvalidOutput => error.PkgConfigInvalidOutput,
else => return err,
};
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95 changes: 77 additions & 18 deletions lib/std/child_process.zig
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Original file line number Diff line number Diff line change
Expand Up @@ -50,8 +50,20 @@ pub const ChildProcess = struct {
err_pipe: if (builtin.os == .windows) void else [2]os.fd_t,
llnode: if (builtin.os == .windows) void else TailQueue(*ChildProcess).Node,

pub const SpawnError = error{OutOfMemory} || os.ExecveError || os.SetIdError ||
os.ChangeCurDirError || windows.CreateProcessError;
pub const SpawnError = error{
OutOfMemory,

/// POSIX-only. `StdIo.Ignore` was selected and opening `/dev/null` returned ENODEV.
NoDevice,

/// Windows-only. One of:
/// * `cwd` was provided and it could not be re-encoded into UTF16LE, or
/// * The `PATH` or `PATHEXT` environment variable contained invalid UTF-8.
InvalidUtf8,

/// Windows-only. `cwd` was provided, but the path did not exist when spawning the child process.
CurrentWorkingDirectoryUnlinked,
} || os.ExecveError || os.SetIdError || os.ChangeCurDirError || windows.CreateProcessError;

pub const Term = union(enum) {
Exited: u32,
Expand Down Expand Up @@ -102,15 +114,15 @@ pub const ChildProcess = struct {
}

/// On success must call `kill` or `wait`.
pub fn spawn(self: *ChildProcess) !void {
pub fn spawn(self: *ChildProcess) SpawnError!void {
if (builtin.os == .windows) {
return self.spawnWindows();
} else {
return self.spawnPosix();
}
}

pub fn spawnAndWait(self: *ChildProcess) !Term {
pub fn spawnAndWait(self: *ChildProcess) SpawnError!Term {
try self.spawn();
return self.wait();
}
Expand Down Expand Up @@ -162,7 +174,13 @@ pub const ChildProcess = struct {

/// Spawns a child process, waits for it, collecting stdout and stderr, and then returns.
/// If it succeeds, the caller owns result.stdout and result.stderr memory.
pub fn exec(allocator: *mem.Allocator, argv: []const []const u8, cwd: ?[]const u8, env_map: ?*const BufMap, max_output_size: usize) !ExecResult {
pub fn exec(
allocator: *mem.Allocator,
argv: []const []const u8,
cwd: ?[]const u8,
env_map: ?*const BufMap,
max_output_size: usize,
) !ExecResult {
const child = try ChildProcess.init(argv, allocator);
defer child.deinit();

Expand Down Expand Up @@ -292,7 +310,7 @@ pub const ChildProcess = struct {
Term{ .Unknown = status };
}

fn spawnPosix(self: *ChildProcess) !void {
fn spawnPosix(self: *ChildProcess) SpawnError!void {
const stdin_pipe = if (self.stdin_behavior == StdIo.Pipe) try os.pipe() else undefined;
errdefer if (self.stdin_behavior == StdIo.Pipe) {
destroyPipe(stdin_pipe);
Expand All @@ -309,7 +327,16 @@ pub const ChildProcess = struct {
};

const any_ignore = (self.stdin_behavior == StdIo.Ignore or self.stdout_behavior == StdIo.Ignore or self.stderr_behavior == StdIo.Ignore);
const dev_null_fd = if (any_ignore) try os.openC(c"/dev/null", os.O_RDWR, 0) else undefined;
const dev_null_fd = if (any_ignore)
os.openC(c"/dev/null", os.O_RDWR, 0) catch |err| switch (err) {
error.PathAlreadyExists => unreachable,
error.NoSpaceLeft => unreachable,
error.FileTooBig => unreachable,
error.DeviceBusy => unreachable,
else => |e| return e,
}
else
undefined;
defer {
if (any_ignore) os.close(dev_null_fd);
}
Expand Down Expand Up @@ -403,7 +430,7 @@ pub const ChildProcess = struct {
}
}

fn spawnWindows(self: *ChildProcess) !void {
fn spawnWindows(self: *ChildProcess) SpawnError!void {
const saAttr = windows.SECURITY_ATTRIBUTES{
.nLength = @sizeOf(windows.SECURITY_ATTRIBUTES),
.bInheritHandle = windows.TRUE,
Expand All @@ -412,11 +439,28 @@ pub const ChildProcess = struct {

const any_ignore = (self.stdin_behavior == StdIo.Ignore or self.stdout_behavior == StdIo.Ignore or self.stderr_behavior == StdIo.Ignore);

const nul_handle = if (any_ignore) blk: {
break :blk try windows.CreateFile("NUL", windows.GENERIC_READ, windows.FILE_SHARE_READ, null, windows.OPEN_EXISTING, windows.FILE_ATTRIBUTE_NORMAL, null);
} else blk: {
break :blk undefined;
};
const nul_handle = if (any_ignore)
windows.CreateFile(
"NUL",
windows.GENERIC_READ,
windows.FILE_SHARE_READ,
null,
windows.OPEN_EXISTING,
windows.FILE_ATTRIBUTE_NORMAL,
null,
) catch |err| switch (err) {
error.SharingViolation => unreachable, // not possible for "NUL"
error.PathAlreadyExists => unreachable, // not possible for "NUL"
error.PipeBusy => unreachable, // not possible for "NUL"
error.InvalidUtf8 => unreachable, // not possible for "NUL"
error.BadPathName => unreachable, // not possible for "NUL"
error.FileNotFound => unreachable, // not possible for "NUL"
error.AccessDenied => unreachable, // not possible for "NUL"
error.NameTooLong => unreachable, // not possible for "NUL"
else => |e| return e,
}
else
undefined;
defer {
if (any_ignore) os.close(nul_handle);
}
Expand Down Expand Up @@ -542,10 +586,25 @@ pub const ChildProcess = struct {
windowsCreateProcess(app_name_w.ptr, cmd_line_w.ptr, envp_ptr, cwd_w_ptr, &siStartInfo, &piProcInfo) catch |no_path_err| {
if (no_path_err != error.FileNotFound) return no_path_err;

const PATH = try process.getEnvVarOwned(self.allocator, "PATH");
defer self.allocator.free(PATH);
const PATHEXT = try process.getEnvVarOwned(self.allocator, "PATHEXT");
defer self.allocator.free(PATHEXT);
var free_path = true;
const PATH = process.getEnvVarOwned(self.allocator, "PATH") catch |err| switch (err) {
error.EnvironmentVariableNotFound => blk: {
free_path = false;
break :blk "";
},
else => |e| return e,
};
defer if (free_path) self.allocator.free(PATH);

var free_path_ext = true;
const PATHEXT = process.getEnvVarOwned(self.allocator, "PATHEXT") catch |err| switch (err) {
error.EnvironmentVariableNotFound => blk: {
free_path_ext = false;
break :blk "";
},
else => |e| return e,
};
defer if (free_path_ext) self.allocator.free(PATHEXT);

var it = mem.tokenize(PATH, ";");
retry: while (it.next()) |search_path| {
Expand Down Expand Up @@ -717,7 +776,7 @@ fn destroyPipe(pipe: [2]os.fd_t) void {
// Child of fork calls this to report an error to the fork parent.
// Then the child exits.
fn forkChildErrReport(fd: i32, err: ChildProcess.SpawnError) noreturn {
writeIntFd(fd, @as(ErrInt,@errorToInt(err))) catch {};
writeIntFd(fd, @as(ErrInt, @errorToInt(err))) catch {};
os.exit(1);
}

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