Commit ca1fd460 authored by Jonathan Coe's avatar Jonathan Coe
Browse files

[clang-format] Do not treat C# attribute targets as labels 

Summary: Merge '[', 'target' , ':' into a single token for C# attributes to
prevent the target from being seen as a label.

Reviewers: MyDeveloperDay, krasimir

Reviewed By: krasimir

Tags: #clang-format

Differential Revision: https://reviews.llvm.org/D74043
parent 9f507bfd

clang/lib/Format/FormatTokenLexer.cpp

+37 −0
Original line number Diff line number Diff line
@@ -76,6 +76,8 @@ void FormatTokenLexer::tryMergePreviousTokens() { 
    return;



  if (Style.isCSharp()) {

    if (tryMergeCSharpAttributeAndTarget())

      return;

    if (tryMergeCSharpKeywordVariables())

      return;

    if (tryMergeCSharpStringLiteral())
@@ -275,6 +277,41 @@ bool FormatTokenLexer::tryMergeCSharpStringLiteral() { 
  return true;

}



// Valid C# attribute targets:

// https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/concepts/attributes/#attribute-targets

const llvm::StringSet<> FormatTokenLexer::CSharpAttributeTargets = {

    "assembly", "module",   "field",  "event", "method",

    "param",    "property", "return", "type",

};



bool FormatTokenLexer::tryMergeCSharpAttributeAndTarget() {

  // Treat '[assembly:' and '[field:' as tokens in their own right.

  if (Tokens.size() < 3)

    return false;



  auto &SquareBracket = *(Tokens.end() - 3);

  auto &Target = *(Tokens.end() - 2);

  auto &Colon = *(Tokens.end() - 1);



  if (!SquareBracket->Tok.is(tok::l_square))

    return false;



  if (CSharpAttributeTargets.find(Target->TokenText) ==

      CSharpAttributeTargets.end())

    return false;



  if (!Colon->Tok.is(tok::colon))

    return false;



  SquareBracket->TokenText =

      StringRef(SquareBracket->TokenText.begin(),

                Colon->TokenText.end() - SquareBracket->TokenText.begin());

  SquareBracket->ColumnWidth += (Target->ColumnWidth + Colon->ColumnWidth);

  Tokens.erase(Tokens.end() - 2);

  Tokens.erase(Tokens.end() - 1);

  return true;

}



bool FormatTokenLexer::tryMergeCSharpDoubleQuestion() {

  if (Tokens.size() < 2)

    return false;

clang/lib/Format/FormatTokenLexer.h

+5 −0
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 
#include "clang/Basic/SourceManager.h"

#include "clang/Format/Format.h"

#include "llvm/ADT/MapVector.h"

#include "llvm/ADT/StringSet.h"

#include "llvm/Support/Regex.h"



#include <stack>
@@ -54,6 +55,7 @@ private: 
  bool tryMergeCSharpNullConditionals();

  bool tryMergeCSharpDoubleQuestion();

  bool tryTransformCSharpForEach();

  bool tryMergeCSharpAttributeAndTarget();



  bool tryMergeTokens(ArrayRef<tok::TokenKind> Kinds, TokenType NewType);
@@ -115,6 +117,9 @@ private: 
  llvm::Regex MacroBlockBeginRegex;

  llvm::Regex MacroBlockEndRegex;



  // Targets that may appear inside a C# attribute.

  static const llvm::StringSet<> CSharpAttributeTargets;



  void readRawToken(FormatToken &Tok);



  void resetLexer(unsigned Offset);

clang/unittests/Format/FormatTestCSharp.cpp

+9 −0
Original line number Diff line number Diff line
@@ -233,6 +233,15 @@ TEST_F(FormatTestCSharp, Attributes) { 
      "[DllImport(\"Hello\", EntryPoint = \"hello_world\")]\n"

      "// The const char* returned by hello_world must not be deleted.\n"

      "private static extern IntPtr HelloFromCpp();)");



  //  Unwrappable lines go on a line of their own.

  // 'target:' is not treated as a label.

  // Modify Style to enforce a column limit.

  FormatStyle Style = getGoogleStyle(FormatStyle::LK_CSharp);

  Style.ColumnLimit = 10;

  verifyFormat(R"([assembly:InternalsVisibleTo(

    "SomeAssembly, PublicKey=SomePublicKeyThatExceedsTheColumnLimit")])",

               Style);

}



TEST_F(FormatTestCSharp, CSharpUsing) {