Reformat lines if they were "moved around".

An unwrapped line can get moved around if there is no newline before
it and the previous line was formatted.

Example:

  template<typename T>  // Cursor is on this line when hitting "format"
  T *getFETokenInfo() const { return static_cast<T*>(FETokenInfo); }

"return .." is the second unwrapped line in this scenario. I does not
touch any reformatted region. Thus, the result of formatting is:

  template <typename T> T *getFETokenInfo() const { return static_cast<T *>(FETokenInfo); }

After second format (and arguably desired end-result):

  template <typename T> T *getFETokenInfo() const {
      return static_cast<T *>(FETokenInfo);
  }

This fixes: llvm.org/PR15060.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175440 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 16 insertions, 1 deletions

diff --git a/lib/Format/Format.cpp b/lib/Format/Format.cpp
index fa62752fe6..e950fe6030 100644
--- a/lib/Format/Format.cpp
+++ b/lib/Format/Format.cpp
@@ -999,7 +999,9 @@ public:
       while (IndentForLevel.size() <= TheLine.Level)
         IndentForLevel.push_back(-1);
       IndentForLevel.resize(TheLine.Level + 1);
-      if (touchesRanges(TheLine) && TheLine.Type != LT_Invalid) {
+      bool WasMoved =
+          PreviousLineWasTouched && TheLine.First.FormatTok.NewlinesBefore == 0;
+      if (TheLine.Type != LT_Invalid && (WasMoved || touchesRanges(TheLine))) {
         unsigned LevelIndent = getIndent(IndentForLevel, TheLine.Level);
         unsigned Indent = LevelIndent;
         if (static_cast<int>(Indent) + Offset >= 0)
diff --git a/unittests/Format/FormatTest.cpp b/unittests/Format/FormatTest.cpp
index c63d7566a9..90196afa62 100644
--- a/unittests/Format/FormatTest.cpp
+++ b/unittests/Format/FormatTest.cpp
@@ -168,6 +168,19 @@ TEST_F(FormatTest, RemovesTrailingWhitespaceOfFormattedLine) {
   EXPECT_EQ("int a;\nint b;", format("int a; \nint b;", 0, 0, getLLVMStyle()));
 }
 
+TEST_F(FormatTest, ReformatsMovedLines) {
+  EXPECT_EQ(
+      "template <typename T> T *getFETokenInfo() const {\n"
+      "  return static_cast<T *>(FETokenInfo);\n"
+      "}\n"
+      "  int a; // <- Should not be formatted",
+      format(
+          "template<typename T>\n"
+          "T *getFETokenInfo() const { return static_cast<T*>(FETokenInfo); }\n"
+          "  int a; // <- Should not be formatted",
+          9, 5, getLLVMStyle()));
+}
+
 //===----------------------------------------------------------------------===//
 // Tests for control statements.
 //===----------------------------------------------------------------------===//