zig build: allow to choose "lazy mode" for fetching process

`--fetch` flag now has additional optional parameter, which specifies
how lazy dependencies should be fetched:
 * `needed` — lazy dependencies are fetched only if they are required
   for current build configuration to work. Default and works same
   as old `--fetch` flag.
 * `all` — lazy dependencies are always fetched. If `--system` flag
   is used after that, it's guaranteed that **any** build configuration
   will not require additional download of dependencies during build.
   Helpful for distro packagers and CI systems:
   https://www.github.com/ziglang/zig/issues/14597#issuecomment-1426827495

If none is passed, behaviour is same as if `needed` was passed.

Signed-off-by: Eric Joldasov <bratishkaerik@landless-city.net>

1 files changed, 10 insertions, 0 deletions

diff --git a/src/main.zig b/src/main.zig
index 865ce78b47..2687546e41 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -4843,6 +4843,7 @@ fn cmdBuild(gpa: Allocator, arena: Allocator, args: []const []const u8) !void {
     var verbose_cimport = false;
     var verbose_llvm_cpu_features = false;
     var fetch_only = false;
+    var fetch_mode: Package.Fetch.JobQueue.Mode = .needed;
     var system_pkg_dir_path: ?[]const u8 = null;
     var debug_target: ?[]const u8 = null;
 
@@ -4924,6 +4925,13 @@ fn cmdBuild(gpa: Allocator, arena: Allocator, args: []const []const u8) !void {
                     reference_trace = 256;
                 } else if (mem.eql(u8, arg, "--fetch")) {
                     fetch_only = true;
+                } else if (mem.startsWith(u8, arg, "--fetch=")) {
+                    fetch_only = true;
+                    const sub_arg = arg["--fetch=".len..];
+                    fetch_mode = std.meta.stringToEnum(Package.Fetch.JobQueue.Mode, sub_arg) orelse
+                        fatal("expected [needed|all] after '--fetch=', found '{s}'", .{
+                            sub_arg,
+                        });
                 } else if (mem.eql(u8, arg, "--system")) {
                     if (i + 1 >= args.len) fatal("expected argument after '{s}'", .{arg});
                     i += 1;
@@ -5208,6 +5216,7 @@ fn cmdBuild(gpa: Allocator, arena: Allocator, args: []const []const u8) !void {
                     .debug_hash = false,
                     .work_around_btrfs_bug = work_around_btrfs_bug,
                     .unlazy_set = unlazy_set,
+                    .mode = fetch_mode,
                 };
                 defer job_queue.deinit();
 
@@ -7130,6 +7139,7 @@ fn cmdFetch(
         .read_only = false,
         .debug_hash = debug_hash,
         .work_around_btrfs_bug = work_around_btrfs_bug,
+        .mode = .all,
     };
     defer job_queue.deinit();