[clang-format] Improve Incomplete detection for (text) protos

Summary:
This patch improves detection of incomplete code for protos and text protos.
This is especially important for text protos in raw string literals, since they
might be partial strings concatenated, and we'd like to disable formatting in
these cases.

Reviewers: sammccall

Reviewed By: sammccall

Subscribers: klimek, cfe-commits

Differential Revision: https://reviews.llvm.org/D44203

llvm-svn: 330016

1 files changed, 18 insertions, 5 deletions

diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index 49e21520b70..f76ae86b4c6 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -592,7 +592,8 @@ private:
           return false;
       }
     }
-    return true;
+    // There are no top-level unbalanced braces in text protos.
+    return Style.Language != FormatStyle::LK_TextProto;
   }
 
   void updateParameterCount(FormatToken *Left, FormatToken *Current) {
@@ -712,6 +713,11 @@ private:
       } else if (Contexts.back().ContextKind == tok::l_paren) {
         Tok->Type = TT_InlineASMColon;
       }
+      // Detects trailing pieces like key:
+      if ((Style.Language == FormatStyle::LK_Proto ||
+           Style.Language == FormatStyle::LK_TextProto) &&
+          !CurrentToken)
+        return false;
       break;
     case tok::pipe:
     case tok::amp:
@@ -798,6 +804,10 @@ private:
           if (Previous && Previous->Type != TT_DictLiteral)
             Previous->Type = TT_SelectorName;
         }
+      } else if (Style.Language == FormatStyle::LK_TextProto ||
+                 Style.Language == FormatStyle::LK_Proto) {
+        // In TT_Proto and TT_TextProto, tok::less cannot be a binary operator.
+        return false;
       } else {
         Tok->Type = TT_BinaryOperator;
         NonTemplateLess.insert(Tok);
@@ -809,13 +819,16 @@ private:
     case tok::r_square:
       return false;
     case tok::r_brace:
-      // Lines can start with '}'.
-      if (Tok->Previous)
+      // Lines can start with '}' except in text protos.
+      if (Tok->Previous || Style.Language == FormatStyle::LK_TextProto)
         return false;
       break;
     case tok::greater:
-      if (Style.Language != FormatStyle::LK_TextProto)
-        Tok->Type = TT_BinaryOperator;
+      // In protos and text protos tok::greater cannot be a binary operator.
+      if (Style.Language == FormatStyle::LK_Proto ||
+          Style.Language == FormatStyle::LK_TextProto)
+        return false;
+      Tok->Type = TT_BinaryOperator;
       break;
     case tok::kw_operator:
       if (Style.Language == FormatStyle::LK_TextProto ||