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Merged
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Feb 7, 2025
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Friendly overloads replace PCWSTR* parameters with ReadOnlySpan<string> #1346

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2 changes: 2 additions & 0 deletions src/Microsoft.Windows.CsWin32/FastSyntaxFactory.cs
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Expand Up @@ -82,6 +82,8 @@ internal static ForStatementSyntax ForStatement(VariableDeclarationSyntax? decla
return SyntaxFactory.ForStatement(Token(SyntaxKind.ForKeyword), Token(SyntaxKind.OpenParenToken), declaration!, default, semicolonToken, condition, semicolonToken, incrementors, Token(SyntaxKind.CloseParenToken), statement);
}

internal static ForEachStatementSyntax ForEachStatement(TypeSyntax type, SyntaxToken identifier, ExpressionSyntax expression, StatementSyntax statement) => SyntaxFactory.ForEachStatement(type, identifier, expression, statement);

internal static StatementSyntax EmptyStatement() => SyntaxFactory.EmptyStatement(Token(SyntaxKind.SemicolonToken));

internal static NamespaceDeclarationSyntax NamespaceDeclaration(NameSyntax name) => SyntaxFactory.NamespaceDeclaration(Token(TriviaList(), SyntaxKind.NamespaceKeyword, TriviaList(Space)), name.WithTrailingTrivia(LineFeed), OpenBrace, default, default, default, CloseBrace, default);
Expand Down
138 changes: 135 additions & 3 deletions src/Microsoft.Windows.CsWin32/Generator.FriendlyOverloads.cs
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Expand Up @@ -5,6 +5,8 @@ namespace Microsoft.Windows.CsWin32;

public partial class Generator
{
private static readonly TypeSyntax PCWSTRTypeSyntax = QualifiedName(QualifiedName(IdentifierName(GlobalWinmdRootNamespaceAlias), IdentifierName("Foundation")), IdentifierName("PCWSTR"));

private enum FriendlyOverloadOf
{
ExternMethod,
Expand Down Expand Up @@ -268,9 +270,6 @@ private IEnumerable<MethodDeclarationSyntax> DeclareFriendlyOverloads(MethodDefi
{
// TODO: add support for in/out size parameters. (e.g. RSGetViewports)
// TODO: add support for lists of pointers via a generated pointer-wrapping struct (e.g. PSSetSamplers)

// It is possible that countParamIndex points to a parameter that is not on the extern method
// when the parameter is the last one and was moved to a return value.
if (!isPointerToPointer && TryHandleCountParam(elementType, nullableSource: true))
{
// This block intentionally left blank.
Expand Down Expand Up @@ -305,6 +304,136 @@ private IEnumerable<MethodDeclarationSyntax> DeclareFriendlyOverloads(MethodDefi
VariableDeclarator(localName.Identifier).WithInitializer(EqualsValueClause(origName))));
arguments[param.SequenceNumber - 1] = Argument(localName);
}

// Translate ReadOnlySpan<PCWSTR> to ReadOnlySpan<string>
if (isIn && !isOut && isConst && externParam.Type is PointerTypeSyntax { ElementType: QualifiedNameSyntax { Right: { Identifier: { ValueText: "PCWSTR" } } } })
{
signatureChanged = true;

// Change the parameter type to ReadOnlySpan<string>
parameters[param.SequenceNumber - 1] = externParam
.WithType(MakeReadOnlySpanOfT(PredefinedType(Token(SyntaxKind.StringKeyword))));

IdentifierNameSyntax gcHandlesLocal = IdentifierName($"{origName}GCHandles");
IdentifierNameSyntax pcwstrLocal = IdentifierName($"{origName}Pointers");

// var paramNameGCHandles = ArrayPool<GCHandle>.Shared.Rent(paramName.Length);
var gcHandlesArrayDecl = LocalDeclarationStatement(VariableDeclaration(
ArrayType(IdentifierName("var"))).AddVariables(
VariableDeclarator(gcHandlesLocal.Identifier).WithInitializer(EqualsValueClause(
InvocationExpression(
MemberAccessExpression(
SyntaxKind.SimpleMemberAccessExpression,
MemberAccessExpression(
SyntaxKind.SimpleMemberAccessExpression,
ParseTypeName("global::System.Buffers.ArrayPool<global::System.Runtime.InteropServices.GCHandle>"),
IdentifierName("Shared")),
IdentifierName("Rent")))
.WithArgumentList(ArgumentList().AddArguments(Argument(GetSpanLength(origName, false))))))));

// var paramNamePointers = ArrayPool<PCWSTR>.Shared.Rent(paramName.Length);
var strsArrayDecl = LocalDeclarationStatement(VariableDeclaration(
ArrayType(IdentifierName("var"))).AddVariables(
VariableDeclarator(pcwstrLocal.Identifier).WithInitializer(EqualsValueClause(
InvocationExpression(
MemberAccessExpression(
SyntaxKind.SimpleMemberAccessExpression,
MemberAccessExpression(
SyntaxKind.SimpleMemberAccessExpression,
ParseTypeName($"global::System.Buffers.ArrayPool<{PCWSTRTypeSyntax.ToString()}>"),
IdentifierName("Shared")),
IdentifierName("Rent")))
.WithArgumentList(ArgumentList().AddArguments(Argument(GetSpanLength(origName, false))))))));

// for (int i = 0; i < paramName.Length; i++)
// {
// paramNameGCHandles[i] = GCHandle.Alloc(paramName[i], GCHandleType.Pinned);
// paramNamePointers[i] = (char*)paramNameGCHandles[i].AddrOfPinnedObject();
// }
IdentifierNameSyntax loopVariable = IdentifierName("i");
var forLoop = ForStatement(
VariableDeclaration(PredefinedType(Token(SyntaxKind.IntKeyword))).AddVariables(
VariableDeclarator(loopVariable.Identifier).WithInitializer(EqualsValueClause(LiteralExpression(SyntaxKind.NumericLiteralExpression, Literal(0))))),
BinaryExpression(SyntaxKind.LessThanExpression, loopVariable, GetSpanLength(origName, false)),
SingletonSeparatedList<ExpressionSyntax>(PostfixUnaryExpression(SyntaxKind.PostIncrementExpression, loopVariable)),
Block().AddStatements(
ExpressionStatement(AssignmentExpression(
SyntaxKind.SimpleAssignmentExpression,
ElementAccessExpression(gcHandlesLocal).AddArgumentListArguments(Argument(loopVariable)),
InvocationExpression(
MemberAccessExpression(
SyntaxKind.SimpleMemberAccessExpression,
ParseTypeName("global::System.Runtime.InteropServices.GCHandle"),
IdentifierName("Alloc")))
.WithArgumentList(ArgumentList().AddArguments(
Argument(ElementAccessExpression(origName).AddArgumentListArguments(Argument(loopVariable))),
Argument(MemberAccessExpression(SyntaxKind.SimpleMemberAccessExpression, ParseTypeName("global::System.Runtime.InteropServices.GCHandleType"), IdentifierName("Pinned"))))))),
ExpressionStatement(AssignmentExpression(
SyntaxKind.SimpleAssignmentExpression,
ElementAccessExpression(pcwstrLocal).AddArgumentListArguments(Argument(loopVariable)),
CastExpression(
PointerType(PredefinedType(Token(SyntaxKind.CharKeyword))),
InvocationExpression(
MemberAccessExpression(
SyntaxKind.SimpleMemberAccessExpression,
ElementAccessExpression(gcHandlesLocal).AddArgumentListArguments(Argument(loopVariable)),
IdentifierName("AddrOfPinnedObject"))).WithArgumentList(ArgumentList()))))));

leadingOutsideTryStatements.AddRange([gcHandlesArrayDecl, strsArrayDecl, forLoop]);

// foreach (var gcHandle in paramNameGCHandles) gcHandle.Free();
var freeHandleStatement = ForEachStatement(
IdentifierName("var").WithTrailingTrivia(Space),
Identifier("gcHandle").WithTrailingTrivia(Space),
gcHandlesLocal.WithLeadingTrivia(Space),
ExpressionStatement(
InvocationExpression(
MemberAccessExpression(
SyntaxKind.SimpleMemberAccessExpression,
IdentifierName("gcHandle"),
IdentifierName("Free")))).WithLeadingTrivia(LineFeed));

// ArrayPool<GCHandle>.Shared.Return(gcHandlesArray);
var returnGCHandlesArray = ExpressionStatement(
InvocationExpression(
MemberAccessExpression(
SyntaxKind.SimpleMemberAccessExpression,
ParseTypeName("global::System.Buffers.ArrayPool<global::System.Runtime.InteropServices.GCHandle>"),
IdentifierName("Shared.Return")))
.WithArgumentList(ArgumentList().AddArguments(Argument(gcHandlesLocal))));

// ArrayPool<PCWSTR>.Shared.Return(paramNamePointers);
var returnStrsArray = ExpressionStatement(
InvocationExpression(
MemberAccessExpression(
SyntaxKind.SimpleMemberAccessExpression,
ParseTypeName($"global::System.Buffers.ArrayPool<{PCWSTRTypeSyntax.ToString()}> "),
IdentifierName("Shared.Return")))
.WithArgumentList(ArgumentList().AddArguments(Argument(pcwstrLocal))));

finallyStatements.AddRange([freeHandleStatement, returnGCHandlesArray, returnStrsArray]);

// Update fixed blocks already created to consume our array of pinned pointers
bool found = false;
for (int i = 0; i < fixedBlocks.Count; i++)
{
if (fixedBlocks[i] is VariableDeclarationSyntax { Variables: [VariableDeclaratorSyntax { Initializer: { Value: IdentifierNameSyntax { Identifier: SyntaxToken id } } initializer } variable] } declaration
&& id.ValueText == externParam.Identifier.ValueText)
{
// fixed (PCWSTR* paramNamePointersPtr = strsArray)
fixedBlocks[i] = declaration.WithVariables(SingletonSeparatedList(variable.WithInitializer(initializer.WithValue(pcwstrLocal))));
found = true;
break;
}
}

if (!found)
{
throw new GenerationFailedException("Unable to find existing fixed block to change.");
}

arguments[param.SequenceNumber - 1] = Argument(localName);
}
}
else if (isIn && isOptional && !isOut && !isPointerToPointer)
{
Expand Down Expand Up @@ -485,6 +614,9 @@ private IEnumerable<MethodDeclarationSyntax> DeclareFriendlyOverloads(MethodDefi
bool TryHandleCountParam(TypeSyntax elementType, bool nullableSource)
{
IdentifierNameSyntax localName = IdentifierName(origName + "Local");

// It is possible that countParamIndex points to a parameter that is not on the extern method
// when the parameter is the last one and was moved to a return value.
if (countParamIndex.HasValue
&& this.canUseSpan
&& externMethodDeclaration.ParameterList.Parameters.Count > countParamIndex.Value
Expand Down
14 changes: 14 additions & 0 deletions src/Microsoft.Windows.CsWin32/Generator.WhitespaceRewriter.cs
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Expand Up @@ -282,6 +282,20 @@ internal WhitespaceRewriter()
}
}

public override SyntaxNode? VisitForEachStatement(ForEachStatementSyntax node)
{
node = this.WithIndentingTrivia(node);
if (node.Statement is BlockSyntax)
{
return base.VisitForEachStatement(node);
}
else
{
using var indent = new Indent(this);
return base.VisitForEachStatement(node);
}
}

public override SyntaxNode? VisitReturnStatement(ReturnStatementSyntax node)
{
return base.VisitReturnStatement(this.WithIndentingTrivia(node));
Expand Down
6 changes: 6 additions & 0 deletions test/GenerationSandbox.Tests/GeneratedForm.cs
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Expand Up @@ -8,6 +8,7 @@
using Windows.Win32.Networking.ActiveDirectory;
using Windows.Win32.System.Com;
using Windows.Win32.System.Diagnostics.Debug;
using Windows.Win32.System.RestartManager;
using Windows.Win32.System.Threading;

#pragma warning disable CA1812 // dead code
Expand Down Expand Up @@ -81,6 +82,11 @@ private static void WriteFile()
PInvoke.WriteFile((SafeHandle?)null, new byte[2], &written, (NativeOverlapped*)null);
}

private static void RmRegisterResources()
{
PInvoke.RmRegisterResources(0, ["a", "b"], [default(RM_UNIQUE_PROCESS)], ["a", "b"]);
}

private class MyStream : IStream
{
public HRESULT Read(void* pv, uint cb, uint* pcbRead)
Expand Down
1 change: 1 addition & 0 deletions test/GenerationSandbox.Tests/NativeMethods.txt
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Expand Up @@ -15,6 +15,7 @@ GetProcAddress
GetTickCount
GetWindowText
GetWindowTextLength
RmRegisterResources
HDC_UserSize
HRESULT_FROM_WIN32
IDirectorySearch
Expand Down
1 change: 1 addition & 0 deletions test/Microsoft.Windows.CsWin32.Tests/FriendlyOverloadTests.cs
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Expand Up @@ -68,6 +68,7 @@ public void OutPWSTR_Parameters_AsSpan()

[Theory]
[InlineData("WSManGetSessionOptionAsString")] // Uses the reserved keyword 'string' as a parameter name
[InlineData("RmRegisterResources")] // Parameter with PCWSTR* (an array of native strings)
public void InterestingAPIs(string name)
{
this.Generate(name);
Expand Down