// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using System.Diagnostics;

namespace ILAssembler;

internal sealed partial class GrammarActions
{
    /// <summary>
    /// Resets the semantic state that must not flow from one document to the next, and defines the input file
    /// as a PDB document.
    /// </summary>
    /// <param name="path">The input file's name as the PDB records it (<see cref="SourceText.Path"/>).</param>
    /// <remarks>
    /// The same <see cref="GrammarActions"/> instance compiles every document of a compilation so that they share
    /// an entity registry. Every rule that introduces namespace, type, method or scope state releases it from its own
    /// <c>finally</c> block, so this is only a safety net for release builds. The <c>.language</c> state carries over
    /// from the previous input file. The <c>.line</c> state does not: the new input file starts without an active
    /// <c>.line</c> directive, and its current document is the file itself (<see cref="SourceLineState"/>).
    /// </remarks>
    internal void BeginDocument(string path)
    {
        Debug.Assert(
            _currentMethod is null
                && _typeOwners.Count == 0
                && _namespaceOwners.Count == 0
                && _suppressedDeclarationOwners.Count == 0
                && _scopeStack.Count == 0
                && _pendingClassMethodOverrides.Count == 0,
            "Nested compiler state must be released by its owning declaration.");
        EndMethod();
        ResetTypeScopes();
        ClearPendingCustomAttributeOwners();
        _pendingClassMethodOverrides.Clear();
        _pdbDocuments.GetOrAdd(path, _currentLanguageGuid);
        _sourceLineStates.Clear();
        _syntaxErrorCount = 0;
    }
}