[clang-format] Use number of unwrapped lines for short namespace

Summary:
This patch makes the namespace comment fixer use the number of unwrapped lines
that a namespace spans to detect it that namespace is short, thus not needing
end comments to be added.
This is needed to ensure clang-format is idempotent. Previously, a short namespace
was detected by the original source code lines. This has the effect of requiring two
runs for this example:
```
namespace { class A; }
```
after first run:
```
namespace {
class A;
}
```
after second run:
```
namespace {
class A;
} // namespace
```

Reviewers: djasper

Reviewed By: djasper

Subscribers: cfe-commits, klimek

Differential Revision: https://reviews.llvm.org/D30528

llvm-svn: 296736

1 files changed, 3 insertions, 10 deletions

diff --git a/clang/lib/Format/NamespaceEndCommentsFixer.cpp b/clang/lib/Format/NamespaceEndCommentsFixer.cpp
index 495c34db754..578dcf7b670 100644
--- a/clang/lib/Format/NamespaceEndCommentsFixer.cpp
+++ b/clang/lib/Format/NamespaceEndCommentsFixer.cpp
@@ -23,7 +23,7 @@ namespace clang {
 namespace format {
 
 namespace {
-// The maximal number of lines that a short namespace spans.
+// The maximal number of unwrapped lines that a short namespace spans.
 // Short namespaces don't need an end comment.
 static const int kShortNamespaceMaxLines = 1;
 
@@ -60,14 +60,6 @@ std::string computeEndCommentText(StringRef NamespaceName, bool AddNewline) {
   return text;
 }
 
-bool isShort(const FormatToken *NamespaceTok, const FormatToken *RBraceTok,
-             const SourceManager &SourceMgr) {
-  int StartLine =
-      SourceMgr.getSpellingLineNumber(NamespaceTok->Tok.getLocation());
-  int EndLine = SourceMgr.getSpellingLineNumber(RBraceTok->Tok.getLocation());
-  return EndLine - StartLine + 1 <= kShortNamespaceMaxLines;
-}
-
 bool hasEndComment(const FormatToken *RBraceTok) {
   return RBraceTok->Next && RBraceTok->Next->is(tok::comment);
 }
@@ -151,7 +143,8 @@ tooling::Replacements NamespaceEndCommentsFixer::analyze(
     const std::string EndCommentText =
         computeEndCommentText(NamespaceName, AddNewline);
     if (!hasEndComment(RBraceTok)) {
-      if (!isShort(NamespaceTok, RBraceTok, SourceMgr))
+      bool isShort = I - StartLineIndex <= kShortNamespaceMaxLines + 1;
+      if (!isShort)
         addEndComment(RBraceTok, EndCommentText, SourceMgr, &Fixes);
       continue;
     }