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