[clang-format] [PR43338] C# clang format has space issues betweern C# only keywords

Summary:
When formatting C# there can be issues with a lack of spaces between `using (` , `foreach (` and generic types

The C# code

```
public class Foo
{
    Dictionary<string,string> foo;
}

```
will be formatted as

```
public class Foo
{
    Dictionary<string, string>foo;
                           ^^^^^   missing a space
}
```

This revision also reverts some of {D66662} in order to make this cleaner and resolve an issues seen by @owenpan that the formatting didn't add a space when not in a code block

This also transforms C# foreach commands to be seen as tok::kw_for commands (to ensure foreach gets the same Brace Wrapping behavior as for without littering the code with `if(Style.isCSharp())`

Reviewers: owenpan, klimek, russellmcc, mitchell-stellar

Reviewed By: mitchell-stellar

Subscribers: cfe-commits

Tags: #clang, #clang-format

Differential Revision: https://reviews.llvm.org/D67660

llvm-svn: 373709

3 files changed, 27 insertions, 5 deletions

diff --git a/clang/lib/Format/FormatTokenLexer.cpp b/clang/lib/Format/FormatTokenLexer.cpp
index e59a059fd6b..5d8a77577c0 100644
--- a/clang/lib/Format/FormatTokenLexer.cpp
+++ b/clang/lib/Format/FormatTokenLexer.cpp
@@ -80,6 +80,8 @@ void FormatTokenLexer::tryMergePreviousTokens() {
       return;
     if (tryMergeCSharpNullConditionals())
       return;
+    if (tryTransformCSharpForEach())
+      return;
     static const tok::TokenKind JSRightArrow[] = {tok::equal, tok::greater};
     if (tryMergeTokens(JSRightArrow, TT_JsFatArrow))
       return;
@@ -254,6 +256,21 @@ bool FormatTokenLexer::tryMergeCSharpNullConditionals() {
   return true;
 }
 
+// In C# transform identifier foreach into kw_foreach
+bool FormatTokenLexer::tryTransformCSharpForEach() {
+  if (Tokens.size() < 1)
+    return false;
+  auto &Identifier = *(Tokens.end() - 1);
+  if (!Identifier->is(tok::identifier))
+    return false;
+  if (Identifier->TokenText != "foreach")
+    return false;
+
+  Identifier->Type = TT_ForEachMacro;
+  Identifier->Tok.setKind(tok::kw_for);
+  return true;
+}
+
 bool FormatTokenLexer::tryMergeLessLess() {
   // Merge X,less,less,Y into X,lessless,Y unless X or Y is less.
   if (Tokens.size() < 3)
diff --git a/clang/lib/Format/FormatTokenLexer.h b/clang/lib/Format/FormatTokenLexer.h
index 1e096fc5020..611211be055 100644
--- a/clang/lib/Format/FormatTokenLexer.h
+++ b/clang/lib/Format/FormatTokenLexer.h
@@ -53,6 +53,7 @@ private:
   bool tryMergeCSharpKeywordVariables();
   bool tryMergeCSharpNullConditionals();
   bool tryMergeCSharpDoubleQuestion();
+  bool tryTransformCSharpForEach();
 
   bool tryMergeTokens(ArrayRef<tok::TokenKind> Kinds, TokenType NewType);
 
diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index 319c66c1ead..e6dfffd9733 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -2640,10 +2640,6 @@ bool TokenAnnotator::spaceRequiredBetween(const AnnotatedLine &Line,
     return Style.Language == FormatStyle::LK_JavaScript ||
            !Left.TokenText.endswith("=*/");
   if (Right.is(tok::l_paren)) {
-    // using (FileStream fs...
-    if (Style.isCSharp() && Left.is(tok::kw_using) &&
-        Style.SpaceBeforeParens != FormatStyle::SBPO_Never)
-      return true;
     if ((Left.is(tok::r_paren) && Left.is(TT_AttributeParen)) ||
         (Left.is(tok::r_square) && Left.is(TT_AttributeSquare)))
       return true;
@@ -2742,7 +2738,15 @@ bool TokenAnnotator::spaceRequiredBefore(const AnnotatedLine &Line,
     // and "%d %d"
     if (Left.is(tok::numeric_constant) && Right.is(tok::percent))
       return Right.WhitespaceRange.getEnd() != Right.WhitespaceRange.getBegin();
-  } else if (Style.Language == FormatStyle::LK_JavaScript || Style.isCSharp()) {
+  } else if (Style.isCSharp()) {
+    // space between type and variable e.g. Dictionary<string,string> foo;
+    if (Left.is(TT_TemplateCloser) && Right.is(TT_StartOfName))
+      return true;
+    // space between keywords and paren e.g. "using ("
+    if (Right.is(tok::l_paren))
+      if (Left.is(tok::kw_using))
+        return spaceRequiredBeforeParens(Left);
+  } else if (Style.Language == FormatStyle::LK_JavaScript) {
     if (Left.is(TT_JsFatArrow))
       return true;
     // for await ( ...