[clang-format] Fix FixNamespaceComments when BraceWrapping AfterNamespace is true.

Summary:
NamespaceEndCommentsFixer did not fix namespace comments when the brace opening the namespace was not on the same line as the "namespace" keyword.
It occurs in Allman, GNU and Linux styles and whenever BraceWrapping.AfterNamespace is true.

Before:
```lang=cpp
    namespace a
    {
    void f();
    void g();
    }
```

After:
```lang=cpp
    namespace a
    {
    void f();
    void g();
    } // namespace a
```

Reviewers: krasimir

Reviewed By: krasimir

Subscribers: klimek, cfe-commits

Differential Revision: https://reviews.llvm.org/D37904

llvm-svn: 314279

clang/lib/Format/NamespaceEndCommentsFixer.cpp

@@ -118,6 +118,12 @@ getNamespaceToken(const AnnotatedLine *line,
     return nullptr;
   assert(StartLineIndex < AnnotatedLines.size());
   const FormatToken *NamespaceTok = AnnotatedLines[StartLineIndex]->First;
+  if (NamespaceTok->is(tok::l_brace)) {
+    // "namespace" keyword can be on the line preceding '{', e.g. in styles
+    // where BraceWrapping.AfterNamespace is true.
+    if (StartLineIndex > 0)
+      NamespaceTok = AnnotatedLines[StartLineIndex - 1]->First;
+  }
   // Detect "(inline)? namespace" in the beginning of a line.
   if (NamespaceTok->is(tok::kw_inline))
     NamespaceTok = NamespaceTok->getNextNonComment();

clang/unittests/Format/FormatTest.cpp

@@ -1413,7 +1413,7 @@ TEST_F(FormatTest, FormatsTypedefEnum) {
   verifyFormat("typedef enum {} EmptyEnum;");
   verifyFormat("typedef enum { A, B, C } ShortEnum;");
   verifyFormat("typedef enum {\n"
-               "  ZERO = 0,\n"             
+               "  ZERO = 0,\n"
                "  ONE = 1,\n"
                "  TWO = 2,\n"
                "  THREE = 3\n"
@@ -1425,7 +1425,7 @@ TEST_F(FormatTest, FormatsTypedefEnum) {
   verifyFormat("typedef enum { A, B, C } ShortEnum;");
   verifyFormat("typedef enum\n"
                "{\n"
-               "  ZERO = 0,\n"             
+               "  ZERO = 0,\n"
                "  ONE = 1,\n"
                "  TWO = 2,\n"
                "  THREE = 3\n"
@@ -9323,7 +9323,7 @@ TEST_F(FormatTest, LinuxBraceBreaking) {
                "struct B {\n"
                "  int x;\n"
                "};\n"
-               "}\n",
+               "} // namespace a\n",
                LinuxBraceStyle);
   verifyFormat("enum X {\n"
                "  Y = 0,\n"
@@ -9453,6 +9453,19 @@ TEST_F(FormatTest, StroustrupBraceBreaking) {
 TEST_F(FormatTest, AllmanBraceBreaking) {
   FormatStyle AllmanBraceStyle = getLLVMStyle();
   AllmanBraceStyle.BreakBeforeBraces = FormatStyle::BS_Allman;
+
+  EXPECT_EQ("namespace a\n"
+            "{\n"
+            "void f();\n"
+            "void g();\n"
+            "} // namespace a\n",
+            format("namespace a\n"
+                   "{\n"
+                   "void f();\n"
+                   "void g();\n"
+                   "}\n",
+                   AllmanBraceStyle));
+
   verifyFormat("namespace a\n"
                "{\n"
                "class A\n"
@@ -9471,7 +9484,7 @@ TEST_F(FormatTest, AllmanBraceBreaking) {
                "{\n"
                "  int x;\n"
                "};\n"
-               "}",
+               "} // namespace a",
                AllmanBraceStyle);
 
   verifyFormat("void f()\n"
@@ -9677,7 +9690,7 @@ TEST_F(FormatTest, GNUBraceBreaking) {
                "  }\n"
                "  void g() { return; }\n"
                "}\n"
-               "}",
+               "} // namespace a",
                GNUBraceStyle);
 
   verifyFormat("void f()\n"