zig/src/introspect.zig

76 lines
2.8 KiB
Zig

const std = @import("std");
const mem = std.mem;
const fs = std.fs;
const Compilation = @import("Compilation.zig");
/// Returns the sub_path that worked, or `null` if none did.
/// The path of the returned Directory is relative to `base`.
/// The handle of the returned Directory is open.
fn testZigInstallPrefix(base_dir: fs.Dir) ?Compilation.Directory {
const test_index_file = "std" ++ fs.path.sep_str ++ "std.zig";
zig_dir: {
// Try lib/zig/std/std.zig
const lib_zig = "lib" ++ fs.path.sep_str ++ "zig";
var test_zig_dir = base_dir.openDir(lib_zig, .{}) catch break :zig_dir;
const file = test_zig_dir.openFile(test_index_file, .{}) catch {
test_zig_dir.close();
break :zig_dir;
};
file.close();
return Compilation.Directory{ .handle = test_zig_dir, .path = lib_zig };
}
// Try lib/std/std.zig
var test_zig_dir = base_dir.openDir("lib", .{}) catch return null;
const file = test_zig_dir.openFile(test_index_file, .{}) catch {
test_zig_dir.close();
return null;
};
file.close();
return Compilation.Directory{ .handle = test_zig_dir, .path = "lib" };
}
/// Both the directory handle and the path are newly allocated resources which the caller now owns.
pub fn findZigLibDir(gpa: *mem.Allocator) !Compilation.Directory {
const self_exe_path = try fs.selfExePathAlloc(gpa);
defer gpa.free(self_exe_path);
return findZigLibDirFromSelfExe(gpa, self_exe_path);
}
/// Both the directory handle and the path are newly allocated resources which the caller now owns.
pub fn findZigLibDirFromSelfExe(
allocator: *mem.Allocator,
self_exe_path: []const u8,
) error{ OutOfMemory, FileNotFound }!Compilation.Directory {
const cwd = fs.cwd();
var cur_path: []const u8 = self_exe_path;
while (fs.path.dirname(cur_path)) |dirname| : (cur_path = dirname) {
var base_dir = cwd.openDir(dirname, .{}) catch continue;
defer base_dir.close();
const sub_directory = testZigInstallPrefix(base_dir) orelse continue;
return Compilation.Directory{
.handle = sub_directory.handle,
.path = try fs.path.join(allocator, &[_][]const u8{ dirname, sub_directory.path.? }),
};
}
return error.FileNotFound;
}
/// Caller owns returned memory.
pub fn resolveGlobalCacheDir(allocator: *mem.Allocator) ![]u8 {
const appname = "zig";
if (std.Target.current.os.tag != .windows) {
if (std.os.getenv("XDG_CACHE_HOME")) |cache_root| {
return fs.path.join(allocator, &[_][]const u8{ cache_root, appname });
} else if (std.os.getenv("HOME")) |home| {
return fs.path.join(allocator, &[_][]const u8{ home, ".cache", appname });
}
}
return fs.getAppDataDir(allocator, appname);
}