Skip to content

Fix dotnet-run-file up-to-date checks across symlinks #52064

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
jjonescz merged 3 commits into from
Dec 11, 2025
Merged

Fix dotnet-run-file up-to-date checks across symlinks #52064

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
f0e5d02
Fix dotnet-run-file up-to-date checks across symlinks
jjonescz Dec 8, 2025
679950b
Improve code and tests
jjonescz Dec 10, 2025
4a8b497
Fix FileNotFoundException
jjonescz Dec 10, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
17 changes: 14 additions & 3 deletions src/Cli/dotnet/Commands/Run/VirtualProjectBuildingCommand.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -847,17 +847,18 @@ Building because previous global properties count ({previousCacheEntry.GlobalPro
}

// Check that the source file is not modified.
if (entryPointFile.LastWriteTimeUtc > buildTimeUtc)
var targetFile = ResolveLinkTargetOrSelf(entryPointFile);
if (targetFile.LastWriteTimeUtc > buildTimeUtc)
{
cache.CanUseCscViaPreviousArguments = true;
Reporter.Verbose.WriteLine("Compiling because entry point file is modified: " + entryPointFile.FullName);
Reporter.Verbose.WriteLine("Compiling because entry point file is modified: " + targetFile.FullName);
return true;
}

// Check that implicit build files are not modified.
foreach (var implicitBuildFilePath in previousCacheEntry.ImplicitBuildFiles)
{
var implicitBuildFileInfo = new FileInfo(implicitBuildFilePath);
var implicitBuildFileInfo = ResolveLinkTargetOrSelf(new FileInfo(implicitBuildFilePath));
if (!implicitBuildFileInfo.Exists || implicitBuildFileInfo.LastWriteTimeUtc > buildTimeUtc)
{
Reporter.Verbose.WriteLine("Building because implicit build file is missing or modified: " + implicitBuildFileInfo.FullName);
Expand All @@ -876,6 +877,16 @@ Building because previous global properties count ({previousCacheEntry.GlobalPro
}

return false;

static FileSystemInfo ResolveLinkTargetOrSelf(FileSystemInfo fileSystemInfo)
{
if (!fileSystemInfo.Exists)
{
return fileSystemInfo;
}

return fileSystemInfo.ResolveLinkTarget(returnFinalTarget: true) ?? fileSystemInfo;
Copy link
Member

@RikkiGibson RikkiGibson Dec 8, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Might be good to exercise the returnFinalTarget behavior, e.g. symlink2 links to symlink1 links to original file, ensuring that symlink2 has correct up to date behavior with respect to original file.

}
}

private static RunFileBuildCacheEntry? DeserializeCacheEntry(string path)
Expand Down
230 changes: 230 additions & 0 deletions test/dotnet.Tests/CommandTests/Run/RunFileTests.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1021,6 +1021,62 @@ public void DirectoryBuildProps()
.And.HaveStdOut("Hello from TestName");
}

/// <summary>
/// Implicit build files are taken from the folder of the symbolic link itself, not its target.
/// This is equivalent to the behavior of symlinked project files.
/// See <see href="https://github.com/dotnet/sdk/pull/52064#issuecomment-3628958688"/>.
/// </summary>
[Fact]
public void DirectoryBuildProps_SymbolicLink()
Copy link
Member

@RikkiGibson RikkiGibson Dec 10, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Thank you for adding the test. I think no need to change behavior in this PR. We can see if anyone complains about this behavior during the upcoming dev cycle, and decide at that point whether there is motivation to make a change.

{
var testInstance = _testAssetsManager.CreateTestDirectory();

var dir1 = Path.Join(testInstance.Path, "dir1");
Directory.CreateDirectory(dir1);

var originalPath = Path.Join(dir1, "original.cs");
File.WriteAllText(originalPath, s_program);

File.WriteAllText(Path.Join(dir1, "Directory.Build.props"), """
<Project>
<PropertyGroup>
<AssemblyName>OriginalAssemblyName</AssemblyName>
</PropertyGroup>
</Project>
""");

var dir2 = Path.Join(testInstance.Path, "dir2");
Directory.CreateDirectory(dir2);

var programFileName = "linked.cs";
var programPath = Path.Join(dir2, programFileName);

File.CreateSymbolicLink(path: programPath, pathToTarget: originalPath);

File.WriteAllText(Path.Join(dir2, "Directory.Build.props"), """
<Project>
<PropertyGroup>
<AssemblyName>LinkedAssemblyName</AssemblyName>
</PropertyGroup>
</Project>
""");

new DotnetCommand(Log, "run", programFileName)
.WithWorkingDirectory(dir2)
.Execute()
.Should().Pass()
.And.HaveStdOut("Hello from LinkedAssemblyName");

// Removing the Directory.Build.props should be detected by up-to-date check.
File.Delete(Path.Join(dir2, "Directory.Build.props"));

new DotnetCommand(Log, "run", programFileName)
.WithWorkingDirectory(dir2)
.Execute()
.Should().Pass()
.And.HaveStdOut("Hello from linked");
}

/// <summary>
/// Overriding default (implicit) properties of file-based apps via implicit build files.
/// </summary>
Expand Down Expand Up @@ -3403,6 +3459,82 @@ public void UpToDate_InvalidOptions()
.And.HaveStdErrContaining(string.Format(CliCommandStrings.CannotCombineOptions, RunCommandParser.NoCacheOption.Name, RunCommandParser.NoBuildOption.Name));
}

/// <summary>
/// <see cref="UpToDate"/> optimization should see through symlinks.
/// See <see href="https://github.com/dotnet/sdk/issues/52063"/>.
/// </summary>
[Fact]
public void UpToDate_SymbolicLink()
{
var testInstance = _testAssetsManager.CreateTestDirectory();

var originalPath = Path.Join(testInstance.Path, "original.cs");
var code = """
#!/usr/bin/env dotnet
Console.WriteLine("v1");
""";
var utf8NoBom = new UTF8Encoding(encoderShouldEmitUTF8Identifier: false);
File.WriteAllText(originalPath, code, utf8NoBom);

var programFileName = "linked";
var programPath = Path.Join(testInstance.Path, programFileName);

File.CreateSymbolicLink(path: programPath, pathToTarget: originalPath);

// Remove artifacts from possible previous runs of this test.
var artifactsDir = VirtualProjectBuildingCommand.GetArtifactsPath(programPath);
if (Directory.Exists(artifactsDir)) Directory.Delete(artifactsDir, recursive: true);

Build(testInstance, BuildLevel.All, expectedOutput: "v1", programFileName: programFileName);

Build(testInstance, BuildLevel.None, expectedOutput: "v1", programFileName: programFileName);

code = code.Replace("v1", "v2");
File.WriteAllText(originalPath, code, utf8NoBom);

Build(testInstance, BuildLevel.Csc, expectedOutput: "v2", programFileName: programFileName);
}

/// <summary>
/// Similar to <see cref="UpToDate_SymbolicLink"/> but with a chain of symlinks.
/// </summary>
[Fact]
public void UpToDate_SymbolicLink2()
{
var testInstance = _testAssetsManager.CreateTestDirectory();

var originalPath = Path.Join(testInstance.Path, "original.cs");
var code = """
#!/usr/bin/env dotnet
Console.WriteLine("v1");
""";
var utf8NoBom = new UTF8Encoding(encoderShouldEmitUTF8Identifier: false);
File.WriteAllText(originalPath, code, utf8NoBom);

var intermediateFileName = "linked1";
var intermediatePath = Path.Join(testInstance.Path, intermediateFileName);

File.CreateSymbolicLink(path: intermediatePath, pathToTarget: originalPath);

var programFileName = "linked2";
var programPath = Path.Join(testInstance.Path, programFileName);

File.CreateSymbolicLink(path: programPath, pathToTarget: intermediatePath);

// Remove artifacts from possible previous runs of this test.
var artifactsDir = VirtualProjectBuildingCommand.GetArtifactsPath(programPath);
if (Directory.Exists(artifactsDir)) Directory.Delete(artifactsDir, recursive: true);

Build(testInstance, BuildLevel.All, expectedOutput: "v1", programFileName: programFileName);

Build(testInstance, BuildLevel.None, expectedOutput: "v1", programFileName: programFileName);

code = code.Replace("v1", "v2");
File.WriteAllText(originalPath, code, utf8NoBom);

Build(testInstance, BuildLevel.Csc, expectedOutput: "v2", programFileName: programFileName);
}

/// <summary>
/// Up-to-date checks and optimizations currently don't support other included files.
/// </summary>
Expand Down Expand Up @@ -3712,6 +3844,41 @@ Hello from Program
""");
}

/// <summary>
/// Combination of <see cref="UpToDate_SymbolicLink"/> and <see cref="CscOnly"/>.
/// </summary>
[Fact]
public void CscOnly_SymbolicLink()
{
var testInstance = _testAssetsManager.CreateTestDirectory(baseDirectory: OutOfTreeBaseDirectory);

var originalPath = Path.Join(testInstance.Path, "original.cs");
var code = """
#!/usr/bin/env dotnet
Console.WriteLine("v1");
""";
var utf8NoBom = new UTF8Encoding(encoderShouldEmitUTF8Identifier: false);
File.WriteAllText(originalPath, code, utf8NoBom);

var programFileName = "linked";
var programPath = Path.Join(testInstance.Path, programFileName);

File.CreateSymbolicLink(path: programPath, pathToTarget: originalPath);

// Remove artifacts from possible previous runs of this test.
var artifactsDir = VirtualProjectBuildingCommand.GetArtifactsPath(programPath);
if (Directory.Exists(artifactsDir)) Directory.Delete(artifactsDir, recursive: true);

Build(testInstance, BuildLevel.Csc, expectedOutput: "v1", programFileName: programFileName);

Build(testInstance, BuildLevel.None, expectedOutput: "v1", programFileName: programFileName);

code = code.Replace("v1", "v2");
File.WriteAllText(originalPath, code, utf8NoBom);

Build(testInstance, BuildLevel.Csc, expectedOutput: "v2", programFileName: programFileName);
}

/// <summary>
/// Tests an optimization which remembers CSC args from prior MSBuild runs and can skip subsequent MSBuild invocations and call CSC directly.
/// This optimization kicks in when the file has some <c>#:</c> directives (then the simpler "hard-coded CSC args" optimization cannot be used).
Expand Down Expand Up @@ -3871,6 +4038,40 @@ public void CscOnly_AfterMSBuild_HardLinks()
Build(testInstance, BuildLevel.Csc, expectedOutput: "Hi from Program");
}

/// <summary>
/// Combination of <see cref="UpToDate_SymbolicLink"/> and <see cref="CscOnly_AfterMSBuild"/>.
/// </summary>
[Fact]
public void CscOnly_AfterMSBuild_SymbolicLink()
{
var testInstance = _testAssetsManager.CreateTestDirectory(baseDirectory: OutOfTreeBaseDirectory);

var originalPath = Path.Join(testInstance.Path, "original.cs");
var code = """
#!/usr/bin/env dotnet
#:property Configuration=Release
Console.WriteLine("v1");
""";
var utf8NoBom = new UTF8Encoding(encoderShouldEmitUTF8Identifier: false);
File.WriteAllText(originalPath, code, utf8NoBom);

var programFileName = "linked";
var programPath = Path.Join(testInstance.Path, programFileName);

File.CreateSymbolicLink(path: programPath, pathToTarget: originalPath);

// Remove artifacts from possible previous runs of this test.
var artifactsDir = VirtualProjectBuildingCommand.GetArtifactsPath(programPath);
if (Directory.Exists(artifactsDir)) Directory.Delete(artifactsDir, recursive: true);

Build(testInstance, BuildLevel.All, expectedOutput: "v1", programFileName: programFileName);

code = code.Replace("v1", "v2");
File.WriteAllText(originalPath, code, utf8NoBom);

Build(testInstance, BuildLevel.Csc, expectedOutput: "v2", programFileName: programFileName);
}

/// <summary>
/// See <see cref="CscOnly_AfterMSBuild"/>.
/// This optimization currently does not support <c>#:project</c> references and hence is disabled if those are present.
Expand Down Expand Up @@ -4398,6 +4599,35 @@ public void EntryPointFilePath_WithUnicodeCharacters()
.And.HaveStdOut($"EntryPointFilePath: {filePath}");
}

[Fact]
public void EntryPointFilePath_SymbolicLink()
{
var testInstance = _testAssetsManager.CreateTestDirectory();
var fileName = "Program.cs";
var programPath = Path.Join(testInstance.Path, fileName);
File.WriteAllText(programPath, """
#!/usr/bin/env dotnet
var entryPointFilePath = AppContext.GetData("EntryPointFilePath") as string;
Console.WriteLine($"EntryPointFilePath: {entryPointFilePath}");
""");

new DotnetCommand(Log, "run", fileName)
.WithWorkingDirectory(testInstance.Path)
.Execute()
.Should().Pass()
.And.HaveStdOut($"EntryPointFilePath: {programPath}");

var linkName = "linked";
var linkPath = Path.Join(testInstance.Path, linkName);
File.CreateSymbolicLink(linkPath, programPath);

new DotnetCommand(Log, "run", linkName)
.WithWorkingDirectory(testInstance.Path)
.Execute()
.Should().Pass()
.And.HaveStdOut($"EntryPointFilePath: {linkPath}");
}

[Fact]
public void MSBuildGet_Simple()
{
Expand Down
Loading