Commit `f7d600675c`

Andrew Kelley <andrew@ziglang.org>

2020-12-11 00:17:02

CLI: improved local cache directory logic

Previously, when choosing the local cache directory, if there was no root source file, an explicitly chosen path, or other clues, zig would choose cwd + zig-cache/ as the local cache directory. This can be problematic if Zig is invoked with the CWD set to a read-only directory, or a directory unrelated to the actual source files being compiled. In the real world, we see this when using `zig cc` with CGo, which for some reason changes the current working directory to the read-only go standard library path before running the C compiler. This commit conservatively chooses to use the global cache directory as the local cache directory when there is no other reasonable choice, and no longer will rely on the cwd path to choose a local cache directory. As a reminder, the --cache-dir CLI flag and ZIG_LOCAL_CACHE_DIR environment variable are available for overriding the decision. For the zig build system, it will always choose the directory that build.zig is + zig-cache/. Closes #7342

master

1 parent 26399b5

Changed files (1)

src

main.zig

@@ -1656,21 +1656,18 @@ fn buildOutputType(
         if (arg_mode == .run) {
             break :l global_cache_directory;
         }
-        const cache_dir_path = blk: {
-            if (root_pkg) |pkg| {
-                if (pkg.root_src_directory.path) |p| {
-                    break :blk try fs.path.join(arena, &[_][]const u8{ p, "zig-cache" });
-                }
-            }
-            break :blk "zig-cache";
-        };
-        const cache_parent_dir = if (root_pkg) |pkg| pkg.root_src_directory.handle else fs.cwd();
-        const dir = try cache_parent_dir.makeOpenPath("zig-cache", .{});
-        cleanup_local_cache_dir = dir;
-        break :l .{
-            .handle = dir,
-            .path = cache_dir_path,
-        };
+        if (root_pkg) |pkg| {
+            const cache_dir_path = try pkg.root_src_directory.join(arena, &[_][]const u8{"zig-cache"});
+            const dir = try pkg.root_src_directory.handle.makeOpenPath("zig-cache", .{});
+            cleanup_local_cache_dir = dir;
+            break :l .{
+                .handle = dir,
+                .path = cache_dir_path,
+            };
+        }
+        // Otherwise we really don't have a reasonable place to put the local cache directory,
+        // so we utilize the global one.
+        break :l global_cache_directory;
     };
 
     if (build_options.have_llvm and emit_asm != .no) {

Commit f7d600675c

Commit `f7d600675c`