SharpGen/GlobalNamespaceProvider.cs

// Copyright (c) 2010-2014 SharpDX - Alexandre Mutel
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

using System;
using System.Collections.Generic;
using System.Runtime.CompilerServices;
using Microsoft.CodeAnalysis.CSharp;
using Microsoft.CodeAnalysis.CSharp.Syntax;

namespace SharpGen
{
    /// <summary>
    ///     Global namespace provider.
    /// </summary>
    public class GlobalNamespaceProvider
    {
        private readonly Dictionary<WellKnownName, string> wellKnownOverrides = new();
        private readonly Dictionary<WellKnownName, NameSyntax> wellKnownOverrideCache = new();
        private readonly Dictionary<WellKnownName, NameSyntax> wellKnownDefaults = new();

        private readonly Dictionary<BuiltinType, NameSyntax> builtInDefaults = new()
        {
            [BuiltinType.Marshal] = SyntaxFactory.ParseName("System.Runtime.InteropServices.Marshal"),
            [BuiltinType.Math] = SyntaxFactory.ParseName("System.Math"),
            [BuiltinType.Unsafe] = SyntaxFactory.ParseName("System.Runtime.CompilerServices.Unsafe"),
            [BuiltinType.Span] = SyntaxFactory.ParseName("System.Span"),
        };

        private readonly Dictionary<BuiltinType, string> builtInOverrides = new();
        private readonly Dictionary<BuiltinType, NameSyntax> builtInOverrideCache = new();

        public string GetTypeName(WellKnownName name) => wellKnownOverrides.TryGetValue(name, out var overridenName)
                                                             ? overridenName
                                                             : WellKnownDefaultName(name);

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        private static string WellKnownDefaultName(WellKnownName name) => "SharpGen.Runtime." + name;

        public NameSyntax GetTypeNameSyntax(WellKnownName name)
        {
            if (wellKnownOverrideCache.TryGetValue(name, out var cache))
                return cache;

            NameSyntax value;
            if (wellKnownOverrides.TryGetValue(name, out var overrideName))
            {
                value = SyntaxFactory.ParseName(overrideName);
                wellKnownOverrideCache.Add(name, value);
                return value;
            }

            if (wellKnownDefaults.TryGetValue(name, out var defaultName))
                return defaultName;

            value = SyntaxFactory.ParseName(WellKnownDefaultName(name));
            wellKnownDefaults.Add(name, value);
            return value;
        }

        public NameSyntax GetTypeNameSyntax(BuiltinType type)
        {
            if (builtInOverrideCache.TryGetValue(type, out var cache))
                return cache;

            if (builtInOverrides.TryGetValue(type, out var overrideName))
            {
                var value = SyntaxFactory.ParseName(overrideName);
                builtInOverrideCache.Add(type, value);
                return value;
            }

            return builtInDefaults[type];
        }

        public NameSyntax GetGenericTypeNameSyntax(BuiltinType type, TypeArgumentListSyntax typeArgumentList)
        {
            if (type != BuiltinType.Span)
                throw new ArgumentOutOfRangeException(nameof(type));

            return SyntaxFactory.QualifiedName(
                SyntaxFactory.IdentifierName("System"),
                SyntaxFactory.GenericName(SyntaxFactory.Identifier("Span")).WithTypeArgumentList(typeArgumentList)
            );
        }

        public void OverrideName(WellKnownName wellKnownName, string name) => wellKnownOverrides[wellKnownName] = name;
        public void OverrideName(BuiltinType builtInName, string name) => builtInOverrides[builtInName] = name;
    }
}