clang-format: [JS] Fix calculation of template string width.

OriginalColumn might not be set, so fall back to Location and SourceMgr
in case it is missing. Also initialize end column in case the token is
multi line, but it's the ` token itself that starts the multi line.

Patch by Martin Probst, thank you!

llvm-svn: 236383

clang/lib/Format/Format.cpp

@@ -782,7 +782,7 @@ private:
       return false;
 
     FormatToken *EndBacktick = Tokens.back();
-    // Backticks get lexed as tok:unknown tokens. If a template string contains
+    // Backticks get lexed as tok::unknown tokens. If a template string contains
     // a comment start, it gets lexed as a tok::comment, or tok::unknown if
     // unterminated.
     if (!EndBacktick->isOneOf(tok::comment, tok::unknown))
@@ -795,7 +795,8 @@ private:
 
     unsigned TokenCount = 0;
     bool IsMultiline = false;
-    unsigned EndColumnInFirstLine = 0;
+    unsigned EndColumnInFirstLine =
+        EndBacktick->OriginalColumn + EndBacktick->ColumnWidth;
     for (auto I = Tokens.rbegin() + 1, E = Tokens.rend(); I != E; I++) {
       ++TokenCount;
       if (I[0]->NewlinesBefore > 0 || I[0]->IsMultiline)
@@ -833,6 +834,15 @@ private:
       Tokens.back()->TokenText =
           StringRef(Tokens.back()->TokenText.data(),
                     EndOffset - Tokens.back()->TokenText.data());
+
+      unsigned EndOriginalColumn = EndBacktick->OriginalColumn;
+      if (EndOriginalColumn == 0) {
+        SourceLocation Loc = EndBacktick->Tok.getLocation();
+        EndOriginalColumn = SourceMgr.getSpellingColumnNumber(Loc);
+      }
+      // If the ` is further down within the token (e.g. in a comment).
+      EndOriginalColumn += CommentBacktickPos;
+
       if (IsMultiline) {
         // ColumnWidth is from backtick to last token in line.
         // LastLineColumnWidth is 0 to backtick.
@@ -840,12 +850,12 @@ private:
         //     until here`;
         Tokens.back()->ColumnWidth =
             EndColumnInFirstLine - Tokens.back()->OriginalColumn;
-        Tokens.back()->LastLineColumnWidth = EndBacktick->OriginalColumn;
+        Tokens.back()->LastLineColumnWidth = EndOriginalColumn;
         Tokens.back()->IsMultiline = true;
       } else {
         // Token simply spans from start to end, +1 for the ` itself.
         Tokens.back()->ColumnWidth =
-            EndBacktick->OriginalColumn - Tokens.back()->OriginalColumn + 1;
+            EndOriginalColumn - Tokens.back()->OriginalColumn + 1;
       }
       return true;
     }

clang/unittests/Format/FormatTestJS.cpp

@@ -646,6 +646,12 @@ TEST_F(FormatTestJS, TemplateStrings) {
       "var x =\n    `multi\n  line`;",
       format("var x = `multi\n  line`;", getGoogleJSStyleWithColumns(14 - 1)));
 
+  // Make sure template strings get a proper ColumnWidth assigned, even if they
+  // are first token in line.
+  verifyFormat(
+      "var a = aaaaaaaaaaaaaaaaaaaaaaaaaaaa ||\n"
+      "        `aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa`;");
+
   // Two template strings.
   verifyFormat("var x = `hello` == `hello`;");