stage2: support multiple files in tests

src/test.zig

@@ -56,6 +56,12 @@ pub const TestContext = struct {
         },
     };
 
+    pub const File = struct {
+        /// Contents of the importable file. Doesn't yet support incremental updates.
+        src: [:0]const u8,
+        path: []const u8,
+    };
+
     pub const TestType = enum {
         Zig,
         ZIR,
@@ -78,6 +84,8 @@ pub const TestContext = struct {
         extension: TestType,
         cbe: bool = false,
 
+        files: std.ArrayList(File),
+
         /// Adds a subcase in which the module is updated with `src`, and the
         /// resulting ZIR is validated against `result`.
         pub fn addTransform(self: *Case, src: [:0]const u8, result: [:0]const u8) void {
@@ -156,6 +164,7 @@ pub const TestContext = struct {
             .updates = std.ArrayList(Update).init(ctx.cases.allocator),
             .output_mode = .Exe,
             .extension = T,
+            .files = std.ArrayList(File).init(ctx.cases.allocator),
         }) catch unreachable;
         return &ctx.cases.items[ctx.cases.items.len - 1];
     }
@@ -182,6 +191,7 @@ pub const TestContext = struct {
             .updates = std.ArrayList(Update).init(ctx.cases.allocator),
             .output_mode = .Obj,
             .extension = T,
+            .files = std.ArrayList(File).init(ctx.cases.allocator),
         }) catch unreachable;
         return &ctx.cases.items[ctx.cases.items.len - 1];
     }
@@ -204,6 +214,7 @@ pub const TestContext = struct {
             .output_mode = .Obj,
             .extension = T,
             .cbe = true,
+            .files = std.ArrayList(File).init(ctx.cases.allocator),
         }) catch unreachable;
         return &ctx.cases.items[ctx.cases.items.len - 1];
     }
@@ -505,6 +516,10 @@ pub const TestContext = struct {
         });
         defer comp.destroy();
 
+        for (case.files.items) |file| {
+            try tmp.dir.writeFile(file.path, file.src);
+        }
+
         for (case.updates.items) |update, update_index| {
             var update_node = root_node.start("update", 3);
             update_node.activate();

test/stage2/test.zig

@@ -909,6 +909,44 @@ pub fn addCases(ctx: *TestContext) !void {
         );
     }
 
+    {
+        var case = ctx.exe("basic import", linux_x64);
+        case.addCompareOutput(
+            \\export fn _start() noreturn {
+            \\    @import("print.zig").print();
+            \\    exit();
+            \\}
+            \\
+            \\fn exit() noreturn {
+            \\    asm volatile ("syscall"
+            \\        :
+            \\        : [number] "{rax}" (231),
+            \\          [arg1] "{rdi}" (@as(usize, 0))
+            \\        : "rcx", "r11", "memory"
+            \\    );
+            \\    unreachable;
+            \\}
+            ,
+            "Hello, World!\n",
+        );
+        try case.files.append(.{
+            .src =
+            \\pub fn print() void {
+            \\    asm volatile ("syscall"
+            \\        :
+            \\        : [number] "{rax}" (@as(usize, 1)),
+            \\          [arg1] "{rdi}" (@as(usize, 1)),
+            \\          [arg2] "{rsi}" (@ptrToInt("Hello, World!\n")),
+            \\          [arg3] "{rdx}" (@as(usize, 14))
+            \\        : "rcx", "r11", "memory"
+            \\    );
+            \\    return;
+            \\}
+            ,
+            .path = "print.zig",
+        });
+    }
+
     {
         var case = ctx.exe("wasm function calls", wasi);