C# CSharpCompilation.Clone方法代码示例

        private static CSharpCompilation GetCompilationWithExternAliases(CSharpCompilation compilation, ImmutableArray<ExternAliasRecord> externAliasRecords)
        {
            if (externAliasRecords.IsDefaultOrEmpty)
            {
                return compilation.Clone();
            }

            var updatedReferences = ArrayBuilder<MetadataReference>.GetInstance();
            var assembliesAndModulesBuilder = ArrayBuilder<Symbol>.GetInstance();
            foreach (var reference in compilation.References)
            {
                updatedReferences.Add(reference);
                assembliesAndModulesBuilder.Add(compilation.GetAssemblyOrModuleSymbol(reference));
            }
            Debug.Assert(assembliesAndModulesBuilder.Count == updatedReferences.Count);

            var assembliesAndModules = assembliesAndModulesBuilder.ToImmutableAndFree();

            foreach (var externAliasRecord in externAliasRecords)
            {
                var targetAssembly = externAliasRecord.TargetAssembly as AssemblySymbol;
                int index;
                if (targetAssembly != null)
                {
                    index = assembliesAndModules.IndexOf(targetAssembly);
                }
                else
                {
                    index = IndexOfMatchingAssembly((AssemblyIdentity)externAliasRecord.TargetAssembly, assembliesAndModules, compilation.Options.AssemblyIdentityComparer);
                }

                if (index < 0)
                {
                    Debug.WriteLine($"Unable to find corresponding assembly reference for extern alias '{externAliasRecord}'");
                    continue;
                }

                var externAlias = externAliasRecord.Alias;

                var assemblyReference = updatedReferences[index];
                var oldAliases = assemblyReference.Properties.Aliases;
                var newAliases = oldAliases.IsEmpty
                    ? ImmutableArray.Create(MetadataReferenceProperties.GlobalAlias, externAlias)
                    : oldAliases.Concat(ImmutableArray.Create(externAlias));

                // NOTE: Dev12 didn't emit custom debug info about "global", so we don't have
                // a good way to distinguish between a module aliased with both (e.g.) "X" and 
                // "global" and a module aliased with only "X".  As in Dev12, we assume that 
                // "global" is a valid alias to remain at least as permissive as source.
                // NOTE: In the event that this introduces ambiguities between two assemblies
                // (e.g. because one was "global" in source and the other was "X"), it should be
                // possible to disambiguate as long as each assembly has a distinct extern alias,
                // not necessarily used in source.
                Debug.Assert(newAliases.Contains(MetadataReferenceProperties.GlobalAlias));

                // Replace the value in the map with the updated reference.
                updatedReferences[index] = assemblyReference.WithAliases(newAliases);
            }

            compilation = compilation.WithReferences(updatedReferences);

            updatedReferences.Free();

            return compilation;
        }

        private static CSharpCompilation GetCompilationWithExternAliases(CSharpCompilation compilation, ImmutableArray<string> externAliasStrings)
        {
            if (externAliasStrings.IsDefaultOrEmpty)
            {
                return compilation.Clone();
            }

            var updatedReferences = ArrayBuilder<MetadataReference>.GetInstance();
            var assemblyIdentities = ArrayBuilder<AssemblyIdentity>.GetInstance();
            foreach (var reference in compilation.References)
            {
                var identity = reference.Properties.Kind == MetadataImageKind.Assembly
                    ? ((AssemblySymbol)compilation.GetAssemblyOrModuleSymbol(reference)).Identity
                    : null;
                assemblyIdentities.Add(identity);
                updatedReferences.Add(reference);
            }
            Debug.Assert(assemblyIdentities.Count == updatedReferences.Count);

            var comparer = compilation.Options.AssemblyIdentityComparer;
            var numAssemblies = assemblyIdentities.Count;

            foreach (var externAliasString in externAliasStrings)
            {
                string alias;
                string externAlias;
                string target;
                ImportTargetKind kind;
                if (!CustomDebugInfoReader.TryParseCSharpImportString(externAliasString, out alias, out externAlias, out target, out kind))
                {
                    Debug.WriteLine("Unable to parse extern alias '{0}'", (object)externAliasString);
                    continue;
                }

                Debug.Assert(kind == ImportTargetKind.Assembly, "Programmer error: How did a non-assembly get in the extern alias list?");
                Debug.Assert(alias == null); // Not used.
                Debug.Assert(externAlias != null); // Name of the extern alias.
                Debug.Assert(target != null); // Name of the target assembly.

                AssemblyIdentity targetIdentity;
                if (!AssemblyIdentity.TryParseDisplayName(target, out targetIdentity))
                {
                    Debug.WriteLine("Unable to parse target of extern alias '{0}'", (object)externAliasString);
                    continue;
                }

                int index = -1;
                for (int i = 0; i < numAssemblies; i++)
                {
                    var candidateIdentity = assemblyIdentities[i];
                    if (candidateIdentity != null && comparer.ReferenceMatchesDefinition(targetIdentity, candidateIdentity))
                    {
                        index = i;
                        break;
                    }
                }

                if (index < 0)
                {
                    Debug.WriteLine("Unable to find corresponding assembly reference for extern alias '{0}'", (object)externAliasString);
                    continue;
                }

                var assemblyReference = updatedReferences[index];
                var oldAliases = assemblyReference.Properties.Aliases;
                var newAliases = oldAliases.IsEmpty
                    ? ImmutableArray.Create(MetadataReferenceProperties.GlobalAlias, externAlias)
                    : oldAliases.Concat(ImmutableArray.Create(externAlias));

                // NOTE: Dev12 didn't emit custom debug info about "global", so we don't have
                // a good way to distinguish between a module aliased with both (e.g.) "X" and 
                // "global" and a module aliased with only "X".  As in Dev12, we assume that 
                // "global" is a valid alias to remain at least as permissive as source.
                // NOTE: In the event that this introduces ambiguities between two assemblies
                // (e.g. because one was "global" in source and the other was "X"), it should be
                // possible to disambiguate as long as each assembly has a distinct extern alias,
                // not necessarily used in source.
                Debug.Assert(newAliases.Contains(MetadataReferenceProperties.GlobalAlias));

                // Replace the value in the map with the updated reference.
                updatedReferences[index] = assemblyReference.WithAliases(newAliases);
            }

            compilation = compilation.WithReferences(updatedReferences);

            assemblyIdentities.Free();
            updatedReferences.Free();

            return compilation;
        }