zig/stage0/stages_test.zig

const std = @import("std");
const Allocator = std.mem.Allocator;
const Ast = std.zig.Ast;
const AstGen = std.zig.AstGen;

const parser_test = @import("parser_test.zig");
const astgen_test = @import("astgen_test.zig");
const sema_test = @import("sema_test.zig");
const c = parser_test.c;
const sc = sema_test.c;
const corpus = @import("corpus.zig");

test "stages: corpus" {
    @setEvalBranchQuota(corpus.files.len * 100);
    const gpa = std.testing.allocator;
    inline for (corpus.files[0..corpus.num_passing]) |path| {
        stagesCheck(gpa, path, @embedFile("../" ++ path)) catch {
            std.debug.print("FAIL: {s}\n", .{path});
            return error.TestFailed;
        };
    }
}

fn stagesCheck(gpa: Allocator, comptime path: []const u8, source: [:0]const u8) !void {
    // Parse once with C parser
    var c_ast = c.astParse(source.ptr, @intCast(source.len));
    defer c.astDeinit(&c_ast);

    // Convert C AST to Zig AST once
    var tree = try parser_test.zigAst(gpa, c_ast);
    defer tree.deinit(gpa);

    // Stage 1: Parser — compare C and Zig ASTs, check canonical rendering
    if (!std.debug.inValgrind()) {
        var zig_tree = try Ast.parse(gpa, source, .zig);
        defer zig_tree.deinit(gpa);
        try parser_test.expectAstConsistent(tree, zig_tree, source);
    }
    if (tree.errors.len == 0) {
        const formatted = try tree.renderAlloc(gpa);
        defer gpa.free(formatted);
        try std.testing.expectEqualStrings(source, formatted);
    }

    // Stage 2: AstGen — compare C and Zig ZIR
    var ref_zir = try AstGen.generate(gpa, tree);
    defer ref_zir.deinit(gpa);

    var c_zir = c.astGen(&c_ast);
    defer c.zirDeinit(&c_zir);

    if (c_zir.has_compile_errors) {
        std.debug.print("C port returned compile errors (inst_len={d})\n", .{c_zir.inst_len});
        return error.TestUnexpectedResult;
    }

    try astgen_test.expectEqualZir(gpa, ref_zir, c_zir);

    // Stage 3: Sema — compare C sema vs pre-computed AIR
    {
        const this_dir = comptime std.fs.path.dirname(@src().file) orelse ".";
        const abs_repo_root = std.fs.cwd().realpathAlloc(gpa, comptime this_dir ++ "/..") catch return error.ResolvePath;
        defer gpa.free(abs_repo_root);

        const repo_dir = comptime std.fs.path.dirname(path) orelse ".";
        var source_dir_buf: [std.fs.max_path_bytes:0]u8 = undefined;
        const source_dir_path = std.fmt.bufPrintZ(&source_dir_buf, "{s}/{s}", .{ abs_repo_root, repo_dir }) catch unreachable;
        var module_root_buf: [std.fs.max_path_bytes:0]u8 = undefined;
        const module_root_path = std.fmt.bufPrintZ(&module_root_buf, "{s}", .{abs_repo_root}) catch unreachable;

        var c_ip = sc.ipInit();
        defer sc.ipDeinit(&c_ip);
        var c_sema: sc.Sema = undefined;
        sc.semaInit(&c_sema, &c_ip, @bitCast(c_zir));
        defer sc.semaDeinit(&c_sema);
        // Pre-generated AIR uses ReleaseSmall (strip=true), so match it.
        c_sema.strip = true;
        // Set source_dir, module_root, root_fqn based on path prefix.
        if (comptime std.mem.startsWith(u8, path, "stage0/")) {
            // Sema unit tests: set module_root to enable std/start/builtin
            // loading, matching the Zig compiler which always creates std
            // even with std_mod=null (Compilation.zig line 2196).
            c_sema.source_dir = source_dir_path.ptr;
            c_sema.module_root = module_root_path.ptr;
            c_sema.root_fqn = comptime sema_test.pathStem(path);
        } else if (comptime std.mem.startsWith(u8, path, "lib/std/")) {
            c_sema.source_dir = source_dir_path.ptr;
            c_sema.module_root = module_root_path.ptr;
            c_sema.root_fqn = "std";
            c_sema.module_prefix = sema_test.pathToModulePrefix(path);
        } else {
            c_sema.source_dir = source_dir_path.ptr;
            c_sema.module_root = module_root_path.ptr;
            c_sema.root_fqn = comptime sema_test.pathStem(path);
        }
        var c_func_air_list = sc.semaAnalyze(&c_sema);
        defer sc.semaFuncAirListDeinit(&c_func_air_list);

        const air_data = @import("air_data").getData(path);
        const precomputed = try sema_test.parsePrecomputedAir(air_data);
        defer sema_test.freePrecomputedAir(precomputed);
        try sema_test.airComparePrecomputed(precomputed, c_func_air_list);
    }
}