Modularize

src/Class/FieldInfo.zig

@@ -0,0 +1,101 @@
+const std = @import("std");
+
+const EnumFlags = @import("../EnumFlags.zig").EnumFlags;
+
+const Class = @import("../Class.zig");
+const ConstantPoolInfo = Class.ConstantPoolInfo;
+const AttributeInfo = Class.AttributeInfo;
+const ResolveError = Class.ResolveError;
+
+access_flags: FieldAccessFlags,
+name_index: u16,
+descriptor_index: u16,
+attributes: []AttributeInfo,
+
+const Self = @This();
+
+pub const FieldFlags = enum(u16) {
+    public = 0x0001,
+    private = 0x0002,
+    protected = 0x0004,
+    static = 0x0008,
+    final = 0x0010,
+    @"volatile" = 0x0040,
+    transient = 0x0080,
+    synthetic = 0x1000,
+    @"enum" = 0x4000,
+};
+
+pub const FieldAccessFlags = EnumFlags(FieldFlags);
+
+pub fn parse(input: *std.Io.Reader, allocator: std.mem.Allocator) !Self {
+    const access_flags: FieldAccessFlags = .{ .mask = try input.takeInt(u16, .big) };
+    const name_index = try input.takeInt(u16, .big);
+    const descriptor_index = try input.takeInt(u16, .big);
+    const attributes = try Class.parseAttributes(input, allocator);
+    return .{
+        .access_flags = access_flags,
+        .name_index = name_index,
+        .descriptor_index = descriptor_index,
+        .attributes = attributes,
+    };
+}
+
+pub fn deinit(self: *Self, allocator: std.mem.Allocator) void {
+    for (self.attributes) |*attr_info| {
+        attr_info.deinit(allocator);
+    }
+    allocator.free(self.attributes);
+}
+
+pub fn format(
+    self: *const Self,
+    w: *std.Io.Writer,
+    depth: usize,
+    indent: u8,
+    allocator: std.mem.Allocator,
+    constant_pool: []const ?ConstantPoolInfo,
+) std.Io.Writer.Error!void {
+    try w.splatByteAll(' ', depth * indent);
+    try w.print("flags: {f}\n", .{ self.access_flags });
+
+    try w.splatByteAll(' ', depth * indent);
+    _ = try w.write("name:\n");
+    const field_name = self.name(constant_pool) catch return error.WriteFailed;
+    try field_name.format(w, depth, indent + 1, constant_pool);
+
+    try w.splatByteAll(' ', depth * indent);
+    _ = try w.write("descriptor:\n");
+    const field_descriptor = self.descriptor(constant_pool) catch return error.WriteFailed;
+    try field_descriptor.format(w, depth, indent + 1, constant_pool);
+
+    try w.splatByteAll(' ', depth * indent);
+    _ = try w.write("attributes:\n");
+    var attr_indent = indent;
+    for (self.attributes, 0..) |*attribute, j| {
+        attr_indent += 1;
+        defer attr_indent -= 1;
+
+        try w.splatByteAll(' ', depth * attr_indent);
+        try w.print("{d}:\n", .{ j });
+
+        try attribute.format(w, depth, attr_indent + 1, allocator, constant_pool);
+    }
+}
+
+pub fn name(self: *const Self, constant_pool: []const ?ConstantPoolInfo) ResolveError!ConstantPoolInfo {
+    const name_index = self.name_index - 1;
+    if (name_index >= constant_pool.len) return ResolveError.InvalidConstantPoolIndex;
+    const cp_info = constant_pool[name_index];
+    if (cp_info == null or @as(ConstantPoolInfo.Tag, cp_info.?) != .utf8) return ResolveError.InvalidConstantType;
+    return cp_info.?;
+}
+
+pub fn descriptor(self: *const Self, constant_pool: []const ?ConstantPoolInfo) ResolveError!ConstantPoolInfo {
+    const descriptor_index = self.descriptor_index - 1;
+    if (descriptor_index >= constant_pool.len) return ResolveError.InvalidConstantPoolIndex;
+    const cp_info = constant_pool[descriptor_index];
+    if (cp_info == null or @as(ConstantPoolInfo.Tag, cp_info.?) != .utf8) return ResolveError.InvalidConstantType;
+    return cp_info.?;
+}
+