Refactor clang-format's formatter.

Summary:
a) Pull out a class LevelIndentTracker whose responsibility is to keep track
   of the indent of levels across multiple annotated lines.
b) Put all responsibility for merging lines into the LineJoiner; make the
   LineJoiner iterate over the lines so we never operate on a line that might
   be merged later; this makes the interface safer to use.
c) Move formatting of the end-of-file whitespace into formatFirstToken.

Fix bugs that became obvious after the refactoring:
1. We would not format lines with offsets correctly inside nested blocks if
   only the outer expression was affected:
   int x = s({ // clang-format only this line
     class X {
       public:
    // ^ this starts at the non-modified indnent level; previously we would
    //   not fix this, now we correctly outdent it.
       void f();
     };
   });
2. We would incorrectly align comments across lines that do not have comments
   for lines with nested blocks:
   int expression; // with comment
   int x = s({
     int y; // comment
     int z; // we would incorrectly align this comment with the comment on
            // 'expression'
   });

llvm-svn: 237104

1 files changed, 27 insertions, 2 deletions

diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 91540d4f2d6..22217c06f4c 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -2775,9 +2775,10 @@ TEST_F(FormatTest, MacroDefinitionsWithIncompleteCode) {
   verifyFormat("#d, = };");
   verifyFormat("#if \"a");
   verifyIncompleteFormat("({\n"
-                         "#define b }\\\n"
+                         "#define b     \\\n"
+                         "  }           \\\n"
                          "  a\n"
-                         "a");
+                         "a", getLLVMStyleWithColumns(15));
   verifyFormat("#define A     \\\n"
                "  {           \\\n"
                "    {\n"
@@ -3179,6 +3180,30 @@ TEST_F(FormatTest, LayoutBlockInsideParens) {
                "  if (a)\n"
                "    f();\n"
                "});");
+  EXPECT_EQ("int longlongname; // comment\n"
+            "int x = f({\n"
+            "  int x; // comment\n"
+            "  int y; // comment\n"
+            "});",
+            format("int longlongname; // comment\n"
+                   "int x = f({\n"
+                   "  int x; // comment\n"
+                   "  int y; // comment\n"
+                   "});",
+                   65, 0, getLLVMStyle()));
+  EXPECT_EQ("int s = f({\n"
+            "  class X {\n"
+            "  public:\n"
+            "    void f();\n"
+            "  };\n"
+            "});",
+            format("int s = f({\n"
+                   "  class X {\n"
+                   "    public:\n"
+                   "    void f();\n"
+                   "  };\n"
+                   "});",
+                   0, 0, getLLVMStyle()));
 }
 
 TEST_F(FormatTest, LayoutBlockInsideStatement) {