Index: include/llvm/Support/Format.h =================================================================== --- include/llvm/Support/Format.h +++ include/llvm/Support/Format.h @@ -125,30 +125,39 @@ return format_object(Fmt, Vals...); } -/// This is a helper class used for left_justify() and right_justify(). +/// This is a helper class for left_justify, right_justify, and center_justify. class FormattedString { +public: + enum Justification { JustifyNone, JustifyLeft, JustifyRight, JustifyCenter }; + FormattedString(StringRef S, unsigned W, Justification J) + : Str(S), Width(W), Justify(J) {} + +private: StringRef Str; unsigned Width; - bool RightJustify; + Justification Justify; friend class raw_ostream; - -public: - FormattedString(StringRef S, unsigned W, bool R) - : Str(S), Width(W), RightJustify(R) { } }; /// left_justify - append spaces after string so total output is /// \p Width characters. If \p Str is larger that \p Width, full string /// is written with no padding. inline FormattedString left_justify(StringRef Str, unsigned Width) { - return FormattedString(Str, Width, false); + return FormattedString(Str, Width, FormattedString::JustifyLeft); } /// right_justify - add spaces before string so total output is /// \p Width characters. If \p Str is larger that \p Width, full string /// is written with no padding. inline FormattedString right_justify(StringRef Str, unsigned Width) { - return FormattedString(Str, Width, true); + return FormattedString(Str, Width, FormattedString::JustifyRight); +} + +/// center_justify - add spaces before and after string so total output is +/// \p Width characters. If \p Str is larger that \p Width, full string +/// is written with no padding. +inline FormattedString center_justify(StringRef Str, unsigned Width) { + return FormattedString(Str, Width, FormattedString::JustifyCenter); } /// This is a helper class used for format_hex() and format_decimal(). Index: lib/Support/raw_ostream.cpp =================================================================== --- lib/Support/raw_ostream.cpp +++ lib/Support/raw_ostream.cpp @@ -326,13 +326,29 @@ } raw_ostream &raw_ostream::operator<<(const FormattedString &FS) { - unsigned Len = FS.Str.size(); - int PadAmount = FS.Width - Len; - if (FS.RightJustify && (PadAmount > 0)) - this->indent(PadAmount); - this->operator<<(FS.Str); - if (!FS.RightJustify && (PadAmount > 0)) + if (FS.Str.size() >= FS.Width || FS.Justify == FormattedString::JustifyNone) { + this->operator<<(FS.Str); + return *this; + } + const size_t Difference = FS.Width - FS.Str.size(); + switch (FS.Justify) { + case FormattedString::JustifyLeft: + this->operator<<(FS.Str); + this->indent(Difference); + break; + case FormattedString::JustifyRight: + this->indent(Difference); + this->operator<<(FS.Str); + break; + case FormattedString::JustifyCenter: { + const int PadAmount = Difference / 2; this->indent(PadAmount); + this->operator<<(FS.Str); + this->indent(PadAmount + (Difference - (PadAmount * 2))); + } break; + default: + llvm_unreachable("Bad Justification"); + } return *this; } Index: unittests/Support/raw_ostream_test.cpp =================================================================== --- unittests/Support/raw_ostream_test.cpp +++ unittests/Support/raw_ostream_test.cpp @@ -151,6 +151,11 @@ EXPECT_EQ(" xyz", printToString(right_justify("xyz", 6), 6)); EXPECT_EQ("abc", printToString(right_justify("abc", 3), 3)); EXPECT_EQ("big", printToString(right_justify("big", 1), 3)); + EXPECT_EQ(" on ", printToString(center_justify("on", 9), 9)); + EXPECT_EQ(" off ", printToString(center_justify("off", 10), 10)); + EXPECT_EQ("single ", printToString(center_justify("single", 7), 7)); + EXPECT_EQ("none", printToString(center_justify("none", 1), 4)); + EXPECT_EQ("none", printToString(center_justify("none", 1), 1)); } TEST(raw_ostreamTest, FormatHex) {