Allow user to set generator newline output type (#1915)

* Allow user defined `NewLine` sequence

* Auto detect line endings

* Handle exception if `git` is not found

Author: duckdoom5

src/Generator/Driver.cs

@@ -45,8 +45,20 @@ void ValidateOptions()
             }
 
             if (Options.NoGenIncludeDirs != null)
+            {
                 foreach (var incDir in Options.NoGenIncludeDirs)
                     ParserOptions.AddIncludeDirs(incDir);
+            }
+
+            NewLineType newLineType = Options.OutputNewLineType;
+            if (Options.OutputNewLineType == NewLineType.Auto)
+            {
+                var sourceNewLineType = GeneratorHelpers.GetNewLineTypeFromGitConfig(Options.OutputDir);
+
+                newLineType = sourceNewLineType ?? NewLineType.Host;
+            }
+
+            TextGenerator.SetLineEndingType(newLineType);
         }
 
         public void Setup()

src/Generator/Generators/CodeGenerator.cs

@@ -140,11 +140,13 @@ public virtual void GenerateComment(RawComment comment)
 
             var lines = new List<string>();
 
-            if (comment.BriefText.Contains("\n"))
+            if (comment.BriefText.Contains('\n'))
             {
+                var commentLines = HtmlEncoder.HtmlEncode(comment.BriefText)
+                    .Split('\n', '\r');
+
                 lines.Add("<summary>");
-                foreach (string line in HtmlEncoder.HtmlEncode(comment.BriefText).Split(
-                                            Environment.NewLine.ToCharArray()))
+                foreach (string line in commentLines)
                 {
                     if (string.IsNullOrWhiteSpace(line))
                         continue;

src/Generator/Options.cs

@@ -15,6 +15,15 @@ public enum GenerationOutputMode
         FilePerUnit
     }
 
+    public enum NewLineType
+    {
+        Auto, // Attempt to auto-detect the new line type using git repository settings of the output directory
+        Host, // Same as Environment.NewLine on the source generator host
+        LF,
+        CR,
+        CRLF,
+    }
+
     public class DriverOptions
     {
         public DriverOptions()
@@ -84,6 +93,8 @@ public bool DoAllModulesHaveLibraries() =>
 
         public string OutputDir;
 
+        public NewLineType OutputNewLineType = NewLineType.Auto;
+
         public bool OutputInteropIncludes;
         public bool GenerateFunctionTemplates;
         /// <summary>

src/Generator/Passes/GetterSetterToPropertyPass.cs

@@ -334,8 +334,8 @@ private static void CombineComments(Property property)
                 Method setter = property.SetMethod;
                 if (getter != setter && setter?.Comment != null)
                 {
-                    comment.BriefText += Environment.NewLine + setter.Comment.BriefText;
-                    comment.Text += Environment.NewLine + setter.Comment.Text;
+                    comment.BriefText += TextGenerator.NewLineChar + setter.Comment.BriefText;
+                    comment.Text += TextGenerator.NewLineChar + setter.Comment.Text;
                     comment.FullComment.Blocks.AddRange(setter.Comment.FullComment.Blocks);
                 }
             }

src/Generator/Utils/BlockGenerator.cs

@@ -135,12 +135,12 @@ public virtual StringBuilder Generate()
                 if (previousBlock != null &&
                     (previousBlock.NewLineKind == NewLineKind.BeforeNextBlock ||
                      (previousBlock.NewLineKind == NewLineKind.IfNotEmpty && !previousBlockEmpty)))
-                    builder.AppendLine();
+                    builder.Append(TextGenerator.NewLineChar);
 
                 builder.Append(childText);
 
                 if (childBlock.NewLineKind == NewLineKind.Always)
-                    builder.AppendLine();
+                    builder.Append(TextGenerator.NewLineChar);
 
                 previousBlock = childBlock;
                 previousBlockEmpty = childText.Length == 0;
@@ -318,7 +318,7 @@ internal ref struct PushedBlock
             private readonly BlockGenerator generator;
             private readonly NewLineKind next;
 
-            public PushedBlock(BlockGenerator generator, NewLineKind next) 
+            public PushedBlock(BlockGenerator generator, NewLineKind next)
             {
                 this.generator = generator;
                 this.next = next;

src/Generator/Utils/ProcessHelper.cs

@@ -7,46 +7,50 @@ public static class ProcessHelper
     {
         public static string Run(string path, string args, out int error, out string errorMessage)
         {
-            using (var process = new Process())
+            return RunFrom(null, path, args, out error, out errorMessage);
+        }
+
+        public static string RunFrom(string workingDir, string path, string args, out int error, out string errorMessage)
+        {
+            using var process = new Process();
+            process.StartInfo.WorkingDirectory = workingDir;
+            process.StartInfo.FileName = path;
+            process.StartInfo.Arguments = args;
+            process.StartInfo.UseShellExecute = false;
+            process.StartInfo.RedirectStandardOutput = true;
+            process.StartInfo.RedirectStandardError = true;
+
+            var reterror = new StringBuilder();
+            var retout = new StringBuilder();
+            process.OutputDataReceived += (sender, outargs) =>
+            {
+                if (string.IsNullOrEmpty(outargs.Data))
+                    return;
+
+                if (retout.Length > 0)
+                    retout.AppendLine();
+                retout.Append(outargs.Data);
+            };
+            process.ErrorDataReceived += (sender, errargs) =>
             {
-                process.StartInfo.FileName = path;
-                process.StartInfo.Arguments = args;
-                process.StartInfo.UseShellExecute = false;
-                process.StartInfo.RedirectStandardOutput = true;
-                process.StartInfo.RedirectStandardError = true;
+                if (string.IsNullOrEmpty(errargs.Data))
+                    return;
 
-                var reterror = new StringBuilder();
-                var retout = new StringBuilder();
-                process.OutputDataReceived += (sender, outargs) =>
-                    {
-                        if (!string.IsNullOrEmpty(outargs.Data))
-                        {
-                            if (retout.Length > 0)
-                                retout.AppendLine();
-                            retout.Append(outargs.Data);
-                        }
-                    };
-                process.ErrorDataReceived += (sender, errargs) =>
-                    {
-                        if (!string.IsNullOrEmpty(errargs.Data))
-                        {
-                            if (reterror.Length > 0)
-                                reterror.AppendLine();
-                            reterror.Append(errargs.Data);
-                        }
-                    };
+                if (reterror.Length > 0)
+                    reterror.AppendLine();
+                reterror.Append(errargs.Data);
+            };
 
-                process.Start();
-                process.BeginOutputReadLine();
-                process.BeginErrorReadLine();
-                process.WaitForExit();
-                process.CancelOutputRead();
-                process.CancelErrorRead();
+            process.Start();
+            process.BeginOutputReadLine();
+            process.BeginErrorReadLine();
+            process.WaitForExit();
+            process.CancelOutputRead();
+            process.CancelErrorRead();
 
-                error = process.ExitCode;
-                errorMessage = reterror.ToString();
-                return retout.ToString();
-            }
+            error = process.ExitCode;
+            errorMessage = reterror.ToString();
+            return retout.ToString();
         }
     }
 }

src/Generator/Utils/TextGenerator.cs

@@ -21,9 +21,11 @@ public interface ITextGenerator
 
     public class TextGenerator : ITextGenerator
     {
+        public static string NewLineChar;
+
         public const uint DefaultIndentation = 4;
 
-        public StringBuilder StringBuilder = new StringBuilder();
+        public StringBuilder StringBuilder = new();
         public bool IsStartOfLine { get; set; }
         public bool NeedsNewLine { get; set; }
         public uint CurrentIndentation { get; set; }
@@ -45,6 +47,19 @@ public TextGenerator Clone()
             return new TextGenerator(this);
         }
 
+        public static void SetLineEndingType(NewLineType newLineType)
+        {
+            NewLineChar = newLineType switch
+            {
+                NewLineType.Host => Environment.NewLine,
+                NewLineType.CR => "\r",
+                NewLineType.LF => "\n",
+                NewLineType.CRLF => "\r\n",
+                NewLineType.Auto => throw new ArgumentException("Don't use Auto here.", nameof(newLineType)),
+                _ => throw new ArgumentOutOfRangeException(nameof(newLineType))
+            };
+        }
+
         public void Write(string msg, params object[] args)
         {
             if (string.IsNullOrEmpty(msg))
@@ -54,11 +69,9 @@ public void Write(string msg, params object[] args)
                 msg = string.Format(msg, args);
 
             if (IsStartOfLine && !string.IsNullOrWhiteSpace(msg))
-                StringBuilder.Append(new string(' ',
-                    (int)(CurrentIndentation * DefaultIndentation)));
+                StringBuilder.Append(new string(' ', (int)(CurrentIndentation * DefaultIndentation)));
 
-            if (msg.Length > 0)
-                IsStartOfLine = msg.EndsWith(Environment.NewLine);
+            IsStartOfLine = msg.Length > 0 && msg.EndsWith(NewLineChar);
 
             StringBuilder.Append(msg);
         }
@@ -90,7 +103,7 @@ internal TextBlock WriteBlock((BlockKind kind, string msg) info)
 
         public void NewLine()
         {
-            StringBuilder.AppendLine(string.Empty);
+            StringBuilder.Append(NewLineChar);
             IsStartOfLine = true;
         }
 

src/Generator/Utils/Utils.cs

@@ -4,6 +4,7 @@
 using System.Reflection;
 using System.Text;
 using System.Text.RegularExpressions;
+using CppSharp.Utils;
 
 namespace CppSharp
 {
@@ -83,7 +84,7 @@ public static void TrimUnderscores(this StringBuilder stringBuilder)
         {
             while (stringBuilder.Length > 0 && stringBuilder[0] == '_')
                 stringBuilder.Remove(0, 1);
-            while (stringBuilder.Length > 0 && stringBuilder[stringBuilder.Length - 1] == '_')
+            while (stringBuilder.Length > 0 && stringBuilder[^1] == '_')
                 stringBuilder.Remove(stringBuilder.Length - 1, 1);
         }
     }
@@ -130,4 +131,59 @@ public static string GetRelativePath(string fromPath, string toPath)
             return uri1.MakeRelativeUri(uri2).ToString();
         }
     }
+
+    public static class GeneratorHelpers
+    {
+        public static NewLineType? GetNewLineTypeFromGitConfig(string outputDir)
+        {
+            try
+            {
+                if (!bool.TryParse(
+                        ProcessHelper.RunFrom(outputDir,
+                            "git", "rev-parse --is-inside-work-tree",
+                            out _, out _
+                        ),
+                        out bool isInsideWorkTree))
+                {
+                    return null;
+                }
+
+                if (!isInsideWorkTree)
+                    return null;
+
+                // Check git config core.eol setting
+                var eolConfig = ProcessHelper.RunFrom(outputDir,
+                        "git", "config --get core.eol",
+                        out _, out _)
+                    .Trim().ToLowerInvariant();
+
+                switch (eolConfig)
+                {
+                    case "lf":
+                        return NewLineType.LF;
+                    case "crlf":
+                        return NewLineType.CRLF;
+                }
+
+                // Otherwise check git config core.autocrlf setting
+                var autoCrLf = ProcessHelper.RunFrom(outputDir,
+                        "git", "config --get core.autocrlf",
+                        out _, out _)
+                    .Trim().ToLowerInvariant();
+
+                return autoCrLf switch
+                {
+                    "input" => NewLineType.LF,
+                    "true" => NewLineType.CRLF,
+                    "false" => NewLineType.Host,
+
+                    _ => null
+                };
+            }
+            catch (Exception)
+            {
+                return null;
+            }
+        }
+    }
 }