Merge pull request #724 from zigtools/comptime-bebe-steps

Implement comptime interpreter

tests/language_features/comptime_interpreter.zig

@@ -0,0 +1,96 @@
+const std = @import("std");
+const zls = @import("zls");
+
+const Ast = std.zig.Ast;
+
+const ComptimeInterpreter = zls.ComptimeInterpreter;
+
+const allocator: std.mem.Allocator = std.testing.allocator;
+
+test "ComptimeInterpreter - basic test" {
+    var config = zls.Config{};
+    var doc_store = zls.DocumentStore{
+        .allocator = allocator,
+        .config = &config,
+    };
+    defer doc_store.deinit();
+
+    _ = try doc_store.openDocument("file:///file.zig",
+        \\pub fn ReturnMyType(comptime my_arg: bool) type {
+        \\    var abc = z: {break :z if (!my_arg) 123 else 0;};
+        \\    if (abc == 123) return u69;
+        \\    return u8;
+        \\}
+    );
+
+    var interpreter = ComptimeInterpreter{
+        .allocator = allocator,
+        .document_store = &doc_store,
+        .uri = "file:///file.zig",
+    };
+    defer interpreter.deinit();
+
+    _ = try interpreter.interpret(0, null, .{});
+
+    var bool_type = try interpreter.createType(std.math.maxInt(std.zig.Ast.Node.Index), .{ .@"bool" = .{} });
+    var arg_false = ComptimeInterpreter.Value{
+        .interpreter = &interpreter,
+        .node_idx = std.math.maxInt(std.zig.Ast.Node.Index),
+        .@"type" = bool_type,
+        .value_data = try interpreter.createValueData(.{ .@"bool" = false }),
+    };
+    var arg_true = ComptimeInterpreter.Value{
+        .interpreter = &interpreter,
+        .node_idx = std.math.maxInt(std.zig.Ast.Node.Index),
+        .@"type" = bool_type,
+        .value_data = try interpreter.createValueData(.{ .@"bool" = true }),
+    };
+
+    const rmt = interpreter.root_type.?.getTypeInfo().@"struct".scope.declarations.get("ReturnMyType").?;
+
+    const call_with_false = try interpreter.call(null, rmt.node_idx, &.{
+        arg_false,
+    }, .{});
+    defer call_with_false.scope.deinit();
+    const call_with_true = try interpreter.call(null, rmt.node_idx, &.{
+        arg_true,
+    }, .{});
+    defer call_with_true.scope.deinit();
+
+    try std.testing.expectFmt("u69", "{any}", .{interpreter.formatTypeInfo(call_with_false.result.value.value_data.@"type".getTypeInfo())});
+    try std.testing.expectFmt("u8", "{any}", .{interpreter.formatTypeInfo(call_with_true.result.value.value_data.@"type".getTypeInfo())});
+}
+
+test "ComptimeInterpreter - struct" {
+    var config = zls.Config{};
+    var doc_store = zls.DocumentStore{
+        .allocator = allocator,
+        .config = &config,
+    };
+    defer doc_store.deinit();
+
+    _ = try doc_store.openDocument("file:///file.zig",
+        \\pub fn ReturnMyType() type {
+        \\    return struct {
+        \\        slay: bool,
+        \\        var abc = 123;
+        \\    };
+        \\}
+    );
+
+    var interpreter = ComptimeInterpreter{
+        .allocator = allocator,
+        .document_store = &doc_store,
+        .uri = "file:///file.zig",
+    };
+    defer interpreter.deinit();
+
+    _ = try interpreter.interpret(0, null, .{});
+
+    const rmt = interpreter.root_type.?.getTypeInfo().@"struct".scope.declarations.get("ReturnMyType").?;
+
+    const z = try interpreter.call(null, rmt.node_idx, &.{}, .{});
+    defer z.scope.deinit();
+
+    try std.testing.expectFmt("struct {slay: bool, var abc: comptime_int = 123, }", "{any}", .{interpreter.formatTypeInfo(z.result.value.value_data.@"type".getTypeInfo())});
+}

tests/tests.zig

@@ -17,4 +17,5 @@ comptime {
 
     // Language features
     _ = @import("language_features/cimport.zig");
+    _ = @import("language_features/comptime_interpreter.zig");
 }