From b39c7e61ef3d0b2ac28a2ce70ef549f2fac834b1 Mon Sep 17 00:00:00 2001
From: Manlio Perillo <manlio.perillo@gmail.com>
Date: Tue, 18 Apr 2023 12:22:30 +0200
Subject: build: restore compatibility support again

Commit e214c44 (build: update ZiglingStep to the new API) broke again
the compatibility support for old compilers, due to the use of the
multi-object for loop syntax.

Move the Zig IPC support code to src/ipc.zig.

Use the while statement, instead of the for statement.
---
 src/ipc.zig | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)
 create mode 100644 src/ipc.zig

(limited to 'src/ipc.zig')

diff --git a/src/ipc.zig b/src/ipc.zig
new file mode 100644
index 0000000..9eaaa13
--- /dev/null
+++ b/src/ipc.zig
@@ -0,0 +1,68 @@
+/// Client side support for Zig IPC.
+const std = @import("std");
+const debug = std.debug;
+const fs = std.fs;
+const mem = std.mem;
+
+const Allocator = mem.Allocator;
+const Client = std.zig.Client;
+const ErrorBundle = std.zig.ErrorBundle;
+const Server = std.zig.Server;
+
+/// This data structure must be kept in sync with zig.Server.Message.EmitBinPath.
+const EmitBinPath = struct {
+    flags: Flags,
+    path: []const u8,
+
+    pub const Flags = Server.Message.EmitBinPath.Flags;
+
+    pub fn deinit(self: *EmitBinPath, allocator: Allocator) void {
+        allocator.free(self.path);
+        self.* = undefined;
+    }
+};
+
+pub fn parseErrorBundle(allocator: Allocator, data: []const u8) !ErrorBundle {
+    const EbHdr = Server.Message.ErrorBundle;
+    const eb_hdr = @ptrCast(*align(1) const EbHdr, data);
+    const extra_bytes =
+        data[@sizeOf(EbHdr)..][0 .. @sizeOf(u32) * eb_hdr.extra_len];
+    const string_bytes =
+        data[@sizeOf(EbHdr) + extra_bytes.len ..][0..eb_hdr.string_bytes_len];
+
+    // TODO: use @ptrCast when the compiler supports it
+    const unaligned_extra = std.mem.bytesAsSlice(u32, extra_bytes);
+    const extra_array = try allocator.alloc(u32, unaligned_extra.len);
+    // TODO: use @memcpy when it supports slices
+    //
+    // Don't use the "multi-object for loop" syntax, in
+    // order to avoid a syntax error with old Zig compilers.
+    var i: usize = 0;
+    while (i < extra_array.len) : (i += 1) {
+        extra_array[i] = unaligned_extra[i];
+    }
+
+    return .{
+        .string_bytes = try allocator.dupe(u8, string_bytes),
+        .extra = extra_array,
+    };
+}
+
+pub fn parseEmitBinPath(allocator: Allocator, data: []const u8) !EmitBinPath {
+    const EbpHdr = Server.Message.EmitBinPath;
+    const ebp_hdr = @ptrCast(*align(1) const EbpHdr, data);
+    const path = try allocator.dupe(u8, data[@sizeOf(EbpHdr)..]);
+
+    return .{
+        .flags = ebp_hdr.flags,
+        .path = path,
+    };
+}
+
+pub fn sendMessage(file: fs.File, tag: Client.Message.Tag) !void {
+    const header: Client.Message.Header = .{
+        .tag = tag,
+        .bytes_len = 0,
+    };
+    try file.writeAll(mem.asBytes(&header));
+}
-- 
cgit v1.2.3-70-g09d2