llvm::format() is somewhat unsafe. The compiler does not check that integer
parameter size matches the %x or %d size and it does not complain when a
StringRef is passed for a %s. And correctly using a StringRef with format() is
ugly because you have to convert it to a std::string then call c_str().
The cases where llvm::format() is useful is controlling how numbers and
strings are printed, especially when you want fixed width output. This
patch adds some new formatting functions to raw_streams to format numbers
and StringRefs in a type safe manner. Some examples:
OS << format_hex(255, 6) => "0x00ff"
OS << format_hex(255, 4) => "0xff"
OS << format_decimal(0, 5) => " 0"
OS << format_decimal(255, 5) => " 255"
OS << right_justify(Str, 5) => " foo"
OS << left_justify(Str, 5) => "foo "
llvm-svn: 218463
- This also shortens the Format.h implementation, and uses the print buffer
fully (it was wasting a character).
- This manifested as llvm-test failures, because one side effect was that
raw_ostream would write garbage '\x00' values into the output stream if it
happened that the string was at the end of the buffer. This meant that grep
would report 'Binary file matches', which meant the silly pattern matching
llvm-test eventually does would fail. Cute. :)
llvm-svn: 79862
Nick Kledzik