#247 Implement pragma once directive.

src/ShaderTools.CodeAnalysis.Hlsl.Tests/Parser/PreprocessorTests.cs

@@ -1071,6 +1071,66 @@ public void TestPragma()
  new DirectiveInfo { Kind = SyntaxKind.PragmaDirectiveTrivia, Status = NodeStatus.IsActive, Text = @"something custom" });
  }
 
+ [Fact]
+ public void TestPragmaOnce()
+ {
+ const string fooText = @"
+#pragma once
+#define FOO
+float foo = 1.0f;
+";
+ const string barText = @"
+#define BAR
+#include <foo.hlsl>
+#include ""foo.hlsl""
+float bar = 2.0f;
+#pragma once 1
+#pragma once : s
+#pragma once()
+#pragma once
+";
+ const string text = @"
+#include <foo.hlsl>
+#include ""foo.hlsl""
+#include ""bar.hlsl""
+#include <foo.hlsl>
+#include ""foo.hlsl""
+#include ""bar.hlsl""
+float rawr = 3.0f;
+#define RAWR
+";
+ var node = Parse(
+ text,
+ new HlslParseOptions
+ {
+ AdditionalIncludeDirectories = { "test" }
+ },
+ new InMemoryFileSystem(new Dictionary<string, string>
+ {
+ { Path.Combine("test", "foo.hlsl"), fooText },
+ { Path.Combine("test2", "bar.hlsl"), barText }
+ }), Path.Combine("test2", "__Root__.hlsl"));
+
+ TestRoundTripping(node, text);
+ VerifyDirectivesSpecial(node,
+ new DirectiveInfo { Kind = SyntaxKind.IncludeDirectiveTrivia, Status = NodeStatus.IsActive },
+ new DirectiveInfo { Kind = SyntaxKind.PragmaDirectiveTrivia, Status = NodeStatus.IsActive },
+ new DirectiveInfo { Kind = SyntaxKind.ObjectLikeDefineDirectiveTrivia, Status = NodeStatus.IsActive },
+ new DirectiveInfo { Kind = SyntaxKind.IncludeDirectiveTrivia, Status = NodeStatus.IsActive },
+ new DirectiveInfo { Kind = SyntaxKind.IncludeDirectiveTrivia, Status = NodeStatus.IsActive },
+ new DirectiveInfo { Kind = SyntaxKind.ObjectLikeDefineDirectiveTrivia, Status = NodeStatus.IsActive },
+ new DirectiveInfo { Kind = SyntaxKind.IncludeDirectiveTrivia, Status = NodeStatus.IsActive },
+ new DirectiveInfo { Kind = SyntaxKind.IncludeDirectiveTrivia, Status = NodeStatus.IsActive },
+ new DirectiveInfo { Kind = SyntaxKind.PragmaDirectiveTrivia, Status = NodeStatus.IsActive },
+ new DirectiveInfo { Kind = SyntaxKind.PragmaDirectiveTrivia, Status = NodeStatus.IsActive },
+ new DirectiveInfo { Kind = SyntaxKind.PragmaDirectiveTrivia, Status = NodeStatus.IsActive },
+ new DirectiveInfo { Kind = SyntaxKind.PragmaDirectiveTrivia, Status = NodeStatus.IsActive },
+ new DirectiveInfo { Kind = SyntaxKind.IncludeDirectiveTrivia, Status = NodeStatus.IsActive },
+ new DirectiveInfo { Kind = SyntaxKind.IncludeDirectiveTrivia, Status = NodeStatus.IsActive },
+ new DirectiveInfo { Kind = SyntaxKind.IncludeDirectiveTrivia, Status = NodeStatus.IsActive },
+ new DirectiveInfo { Kind = SyntaxKind.ObjectLikeDefineDirectiveTrivia, Status = NodeStatus.IsActive });
+ }
+
  [Fact]
  public void HandlesVirtualDirectoryMapping_IncludeIsInRootOfVirtualDirectory_IncludeHandledSuccessfully()
  {
@@ -1174,9 +1234,9 @@ private static IReadOnlyList<SyntaxToken> LexAllTokens(string text)
  return SyntaxFactory.ParseAllTokens(new SourceFile(SourceText.From(text)));
  }
 
- private static CompilationUnitSyntax Parse(string text, HlslParseOptions options = null, IIncludeFileSystem fileSystem = null)
+ private static CompilationUnitSyntax Parse(string text, HlslParseOptions options = null, IIncludeFileSystem fileSystem = null, string filePath = "__Root__.hlsl")
  {
- return SyntaxFactory.ParseCompilationUnit(new SourceFile(SourceText.From(text), "__Root__.hlsl"), options, fileSystem);
+ return SyntaxFactory.ParseCompilationUnit(new SourceFile(SourceText.From(text), filePath), options, fileSystem);
  }
 
  private static void TestRoundTripping(CompilationUnitSyntax node, string text, bool disallowErrors = true)

src/ShaderTools.CodeAnalysis.Hlsl/Parser/DirectiveParser.cs

@@ -293,6 +293,9 @@ private PragmaDirectiveTriviaSyntax ParsePragmaDirective(SyntaxToken hash, Synta
 
  var eod = ParseEndOfDirective(false);
 
+ if (body.Count > 0 && body.First().ContextualKind == SyntaxKind.OnceKeyword)
+ _lexer.ApplyPragmaOnceDirective();
+
  return new PragmaDirectiveTriviaSyntax(hash, keyword, body, eod, isActive);
  }
 

src/ShaderTools.CodeAnalysis.Hlsl/Parser/HlslLexer.cs

@@ -17,12 +17,14 @@ namespace ShaderTools.CodeAnalysis.Hlsl.Parser
  public sealed partial class HlslLexer : ILexer
  {
  private readonly IIncludeFileResolver _includeFileResolver;
+ private readonly HashSet<string> _includeOnceList = new HashSet<string>();
  private readonly List<SyntaxNode> _leadingTrivia = new List<SyntaxNode>();
  private readonly List<SyntaxNode> _trailingTrivia = new List<SyntaxNode>();
  private readonly List<Diagnostic> _diagnostics = new List<Diagnostic>();
 
  private LexerMode _mode;
  public bool ExpandMacros { get; set; }
+ public void ApplyPragmaOnceDirective() { _includeOnceList.Add(File.FilePath); }
 
  private List<SyntaxToken> _expandedMacroTokens;
  private int _expandedMacroIndex;
@@ -338,7 +340,8 @@ private bool LexDirectiveAndExcludedTrivia(
  if (include != null)
  {
  triviaList.Add(includeDirective);
- PushIncludeContext(include);
+ if (!_includeOnceList.Contains(include.FilePath))
+ PushIncludeContext(include);
  return false;
  }
  }

src/ShaderTools.CodeAnalysis.Hlsl/Syntax/SyntaxFacts.cs

@@ -219,6 +219,8 @@ public static string GetText(this SyntaxKind kind)
  return "min16int";
  case SyntaxKind.Min16UintKeyword:
  return "min16uint";
+ case SyntaxKind.OnceKeyword:
+ return "once";
  case SyntaxKind.OutKeyword:
  return "out";
  case SyntaxKind.PackMatrixKeyword:
@@ -2854,6 +2856,8 @@ public static SyntaxKind GetPreprocessorKeywordKind(string text)
  return SyntaxKind.PackMatrixKeyword;
  case "warning":
  return SyntaxKind.WarningKeyword;
+ case "once":
+ return SyntaxKind.OnceKeyword;
  default:
  return SyntaxKind.IdentifierToken;
  }
@@ -2880,6 +2884,7 @@ public static bool IsPreprocessorKeyword(this SyntaxKind kind)
  case SyntaxKind.MessageKeyword:
  case SyntaxKind.PackMatrixKeyword:
  case SyntaxKind.WarningKeyword:
+ case SyntaxKind.OnceKeyword:
  return true;
 
  default:

src/ShaderTools.CodeAnalysis.Hlsl/Syntax/SyntaxKind.cs

@@ -324,6 +324,7 @@ public enum SyntaxKind
  NointerpolationKeyword,
  NoperspectiveKeyword,
  NullKeyword,
+ OnceKeyword,
  OutKeyword,
  OutputPatchKeyword,
  PackMatrixKeyword,
@@ -415,8 +416,8 @@ public enum SyntaxKind
  Uint4x2Keyword,
  Uint4x3Keyword,
  Uint4x4Keyword,
- Uint64_tKeyword,
- Uint64_t1Keyword,
+ Uint64_tKeyword,
+ Uint64_t1Keyword,
  Uint64_t2Keyword,
  Uint64_t3Keyword,
  Uint64_t4Keyword,
@@ -436,8 +437,8 @@ public enum SyntaxKind
  Uint64_t4x2Keyword,
  Uint64_t4x3Keyword,
  Uint64_t4x4Keyword,
- Uint16_tKeyword,
- Uint16_t1Keyword,
+ Uint16_tKeyword,
+ Uint16_t1Keyword,
  Uint16_t2Keyword,
  Uint16_t3Keyword,
  Uint16_t4Keyword,