clang-format: Fix bad merging of lines in nested blocks.

Before:
  SomeFunction([]() {
  #define A a
    return 43; });

After:
  SomeFunction([]() {
  #define A a
    return 43;
  });

llvm-svn: 220684

3 files changed, 18 insertions, 5 deletions

diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
index b9d13ab691e..8960823488f 100644
--- a/clang/lib/Format/Format.cpp
+++ b/clang/lib/Format/Format.cpp
@@ -1277,6 +1277,9 @@ private:
       return true;
     }
 
+    if (Previous.Children[0]->First->MustBreakBefore)
+      return false;
+
     // Cannot merge multiple statements into a single line.
     if (Previous.Children.size() > 1)
       return false;
diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index a324d2fa472..0cc37b15743 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -1362,13 +1362,15 @@ void TokenAnnotator::calculateFormattingInformation(AnnotatedLine &Line) {
       ChildSize = LastOfChild.isTrailingComment() ? Style.ColumnLimit
                                                   : LastOfChild.TotalLength + 1;
     }
-    if (Current->MustBreakBefore || Current->Previous->Children.size() > 1 ||
+    const FormatToken *Prev= Current->Previous;
+    if (Current->MustBreakBefore || Prev->Children.size() > 1 ||
+        (Prev->Children.size() == 1 &&
+         Prev->Children[0]->First->MustBreakBefore) ||
         Current->IsMultiline)
-      Current->TotalLength = Current->Previous->TotalLength + Style.ColumnLimit;
+      Current->TotalLength = Prev->TotalLength + Style.ColumnLimit;
     else
-      Current->TotalLength = Current->Previous->TotalLength +
-                             Current->ColumnWidth + ChildSize +
-                             Current->SpacesRequiredBefore;
+      Current->TotalLength = Prev->TotalLength + Current->ColumnWidth +
+                             ChildSize + Current->SpacesRequiredBefore;
 
     if (Current->Type == TT_CtorInitializerColon)
       InFunctionDecl = false;
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 5642b0f9e65..f29aff8f0e9 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -9103,6 +9103,14 @@ TEST_F(FormatTest, FormatsLambdas) {
   verifyFormat("SomeFunction([]() { // A cool function...\n"
                "  return 43;\n"
                "});");
+  EXPECT_EQ("SomeFunction([]() {\n"
+            "#define A a\n"
+            "  return 43;\n"
+            "});",
+            format("SomeFunction([](){\n"
+                   "#define A a\n"
+                   "return 43;\n"
+                   "});"));
   verifyFormat("void f() {\n"
                "  SomeFunction([](decltype(x), A *a) {});\n"
                "}");