Implemented llvm::sys::locale::columnWidth and isPrint for the case of generic UTF8-capable terminal.

Summary:
This is a second attempt to get this right. After reading the Unicode
Standard I came up with the code that uses definitions of "printable" and
"column width" more suitable for terminal output (i.e. fixed-width fonts and
special treatment of many control characters).
The implementation here can probably be used for Windows and MacOS if someone
can test it properly.
The patch addresses PR14910.

Reviewers: jordan_rose, gribozavr

CC: llvm-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D1253

llvm-svn: 187837

1 files changed, 370 insertions, 5 deletions

diff --git a/llvm/lib/Support/LocaleGeneric.inc b/llvm/lib/Support/LocaleGeneric.inc
index 278deee3e4d..3a939b826bf 100644
--- a/llvm/lib/Support/LocaleGeneric.inc
+++ b/llvm/lib/Support/LocaleGeneric.inc
@@ -1,15 +1,380 @@
-#include <cwctype>
+//===- llvm/Support/LocaleGeneric.inc - Locale-dependent stuff  -*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements llvm::sys::locale::columnWidth and
+// llvm::sys::locale::isPrint functions for UTF-8 locales.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/Support/ConvertUTF.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/UnicodeCharRanges.h"
 
 namespace llvm {
 namespace sys {
 namespace locale {
 
-int columnWidth(StringRef s) {
-    return s.size();
+enum ColumnWidthErrors {
+  ErrorInvalidUTF8 = -2,
+  ErrorNonPrintableCharacter = -1
+};
+
+/// Determines if a character is likely to be displayed correctly on the
+/// terminal. Exact implementation would have to depend on the specific
+/// terminal, so we define the semantic that should be suitable for generic case
+/// of a terminal capable to output Unicode characters.
+/// All characters from the Unicode codepoint range are considered printable
+/// except for:
+///   * C0 and C1 control character ranges;
+///   * default ignorable code points as per 5.21 of
+///     http://www.unicode.org/versions/Unicode6.2.0/UnicodeStandard-6.2.pdf
+///   * format characters (category = Cf);
+///   * surrogates (category = Cs);
+///   * unassigned characters (category = Cn).
+/// \return true if the character is considered printable.
+bool isPrint(int UCS) {
+  // Sorted list of non-overlapping intervals of code points that are not
+  // supposed to be printable.
+  static const UnicodeCharRange NonPrintableRanges[] = {
+    { 0x0000, 0x001F }, { 0x007F, 0x009F }, { 0x00AD, 0x00AD },
+    { 0x034F, 0x034F }, { 0x0378, 0x0379 }, { 0x037F, 0x0383 },
+    { 0x038B, 0x038B }, { 0x038D, 0x038D }, { 0x03A2, 0x03A2 },
+    { 0x0528, 0x0530 }, { 0x0557, 0x0558 }, { 0x0560, 0x0560 },
+    { 0x0588, 0x0588 }, { 0x058B, 0x058E }, { 0x0590, 0x0590 },
+    { 0x05C8, 0x05CF }, { 0x05EB, 0x05EF }, { 0x05F5, 0x0605 },
+    { 0x061C, 0x061D }, { 0x06DD, 0x06DD }, { 0x070E, 0x070F },
+    { 0x074B, 0x074C }, { 0x07B2, 0x07BF }, { 0x07FB, 0x07FF },
+    { 0x082E, 0x082F }, { 0x083F, 0x083F }, { 0x085C, 0x085D },
+    { 0x085F, 0x089F }, { 0x08A1, 0x08A1 }, { 0x08AD, 0x08E3 },
+    { 0x08FF, 0x08FF }, { 0x0978, 0x0978 }, { 0x0980, 0x0980 },
+    { 0x0984, 0x0984 }, { 0x098D, 0x098E }, { 0x0991, 0x0992 },
+    { 0x09A9, 0x09A9 }, { 0x09B1, 0x09B1 }, { 0x09B3, 0x09B5 },
+    { 0x09BA, 0x09BB }, { 0x09C5, 0x09C6 }, { 0x09C9, 0x09CA },
+    { 0x09CF, 0x09D6 }, { 0x09D8, 0x09DB }, { 0x09DE, 0x09DE },
+    { 0x09E4, 0x09E5 }, { 0x09FC, 0x0A00 }, { 0x0A04, 0x0A04 },
+    { 0x0A0B, 0x0A0E }, { 0x0A11, 0x0A12 }, { 0x0A29, 0x0A29 },
+    { 0x0A31, 0x0A31 }, { 0x0A34, 0x0A34 }, { 0x0A37, 0x0A37 },
+    { 0x0A3A, 0x0A3B }, { 0x0A3D, 0x0A3D }, { 0x0A43, 0x0A46 },
+    { 0x0A49, 0x0A4A }, { 0x0A4E, 0x0A50 }, { 0x0A52, 0x0A58 },
+    { 0x0A5D, 0x0A5D }, { 0x0A5F, 0x0A65 }, { 0x0A76, 0x0A80 },
+    { 0x0A84, 0x0A84 }, { 0x0A8E, 0x0A8E }, { 0x0A92, 0x0A92 },
+    { 0x0AA9, 0x0AA9 }, { 0x0AB1, 0x0AB1 }, { 0x0AB4, 0x0AB4 },
+    { 0x0ABA, 0x0ABB }, { 0x0AC6, 0x0AC6 }, { 0x0ACA, 0x0ACA },
+    { 0x0ACE, 0x0ACF }, { 0x0AD1, 0x0ADF }, { 0x0AE4, 0x0AE5 },
+    { 0x0AF2, 0x0B00 }, { 0x0B04, 0x0B04 }, { 0x0B0D, 0x0B0E },
+    { 0x0B11, 0x0B12 }, { 0x0B29, 0x0B29 }, { 0x0B31, 0x0B31 },
+    { 0x0B34, 0x0B34 }, { 0x0B3A, 0x0B3B }, { 0x0B45, 0x0B46 },
+    { 0x0B49, 0x0B4A }, { 0x0B4E, 0x0B55 }, { 0x0B58, 0x0B5B },
+    { 0x0B5E, 0x0B5E }, { 0x0B64, 0x0B65 }, { 0x0B78, 0x0B81 },
+    { 0x0B84, 0x0B84 }, { 0x0B8B, 0x0B8D }, { 0x0B91, 0x0B91 },
+    { 0x0B96, 0x0B98 }, { 0x0B9B, 0x0B9B }, { 0x0B9D, 0x0B9D },
+    { 0x0BA0, 0x0BA2 }, { 0x0BA5, 0x0BA7 }, { 0x0BAB, 0x0BAD },
+    { 0x0BBA, 0x0BBD }, { 0x0BC3, 0x0BC5 }, { 0x0BC9, 0x0BC9 },
+    { 0x0BCE, 0x0BCF }, { 0x0BD1, 0x0BD6 }, { 0x0BD8, 0x0BE5 },
+    { 0x0BFB, 0x0C00 }, { 0x0C04, 0x0C04 }, { 0x0C0D, 0x0C0D },
+    { 0x0C11, 0x0C11 }, { 0x0C29, 0x0C29 }, { 0x0C34, 0x0C34 },
+    { 0x0C3A, 0x0C3C }, { 0x0C45, 0x0C45 }, { 0x0C49, 0x0C49 },
+    { 0x0C4E, 0x0C54 }, { 0x0C57, 0x0C57 }, { 0x0C5A, 0x0C5F },
+    { 0x0C64, 0x0C65 }, { 0x0C70, 0x0C77 }, { 0x0C80, 0x0C81 },
+    { 0x0C84, 0x0C84 }, { 0x0C8D, 0x0C8D }, { 0x0C91, 0x0C91 },
+    { 0x0CA9, 0x0CA9 }, { 0x0CB4, 0x0CB4 }, { 0x0CBA, 0x0CBB },
+    { 0x0CC5, 0x0CC5 }, { 0x0CC9, 0x0CC9 }, { 0x0CCE, 0x0CD4 },
+    { 0x0CD7, 0x0CDD }, { 0x0CDF, 0x0CDF }, { 0x0CE4, 0x0CE5 },
+    { 0x0CF0, 0x0CF0 }, { 0x0CF3, 0x0D01 }, { 0x0D04, 0x0D04 },
+    { 0x0D0D, 0x0D0D }, { 0x0D11, 0x0D11 }, { 0x0D3B, 0x0D3C },
+    { 0x0D45, 0x0D45 }, { 0x0D49, 0x0D49 }, { 0x0D4F, 0x0D56 },
+    { 0x0D58, 0x0D5F }, { 0x0D64, 0x0D65 }, { 0x0D76, 0x0D78 },
+    { 0x0D80, 0x0D81 }, { 0x0D84, 0x0D84 }, { 0x0D97, 0x0D99 },
+    { 0x0DB2, 0x0DB2 }, { 0x0DBC, 0x0DBC }, { 0x0DBE, 0x0DBF },
+    { 0x0DC7, 0x0DC9 }, { 0x0DCB, 0x0DCE }, { 0x0DD5, 0x0DD5 },
+    { 0x0DD7, 0x0DD7 }, { 0x0DE0, 0x0DF1 }, { 0x0DF5, 0x0E00 },
+    { 0x0E3B, 0x0E3E }, { 0x0E5C, 0x0E80 }, { 0x0E83, 0x0E83 },
+    { 0x0E85, 0x0E86 }, { 0x0E89, 0x0E89 }, { 0x0E8B, 0x0E8C },
+    { 0x0E8E, 0x0E93 }, { 0x0E98, 0x0E98 }, { 0x0EA0, 0x0EA0 },
+    { 0x0EA4, 0x0EA4 }, { 0x0EA6, 0x0EA6 }, { 0x0EA8, 0x0EA9 },
+    { 0x0EAC, 0x0EAC }, { 0x0EBA, 0x0EBA }, { 0x0EBE, 0x0EBF },
+    { 0x0EC5, 0x0EC5 }, { 0x0EC7, 0x0EC7 }, { 0x0ECE, 0x0ECF },
+    { 0x0EDA, 0x0EDB }, { 0x0EE0, 0x0EFF }, { 0x0F48, 0x0F48 },
+    { 0x0F6D, 0x0F70 }, { 0x0F98, 0x0F98 }, { 0x0FBD, 0x0FBD },
+    { 0x0FCD, 0x0FCD }, { 0x0FDB, 0x0FFF }, { 0x10C6, 0x10C6 },
+    { 0x10C8, 0x10CC }, { 0x10CE, 0x10CF }, { 0x115F, 0x1160 },
+    { 0x1249, 0x1249 }, { 0x124E, 0x124F }, { 0x1257, 0x1257 },
+    { 0x1259, 0x1259 }, { 0x125E, 0x125F }, { 0x1289, 0x1289 },
+    { 0x128E, 0x128F }, { 0x12B1, 0x12B1 }, { 0x12B6, 0x12B7 },
+    { 0x12BF, 0x12BF }, { 0x12C1, 0x12C1 }, { 0x12C6, 0x12C7 },
+    { 0x12D7, 0x12D7 }, { 0x1311, 0x1311 }, { 0x1316, 0x1317 },
+    { 0x135B, 0x135C }, { 0x137D, 0x137F }, { 0x139A, 0x139F },
+    { 0x13F5, 0x13FF }, { 0x169D, 0x169F }, { 0x16F1, 0x16FF },
+    { 0x170D, 0x170D }, { 0x1715, 0x171F }, { 0x1737, 0x173F },
+    { 0x1754, 0x175F }, { 0x176D, 0x176D }, { 0x1771, 0x1771 },
+    { 0x1774, 0x177F }, { 0x17B4, 0x17B5 }, { 0x17DE, 0x17DF },
+    { 0x17EA, 0x17EF }, { 0x17FA, 0x17FF }, { 0x180B, 0x180D },
+    { 0x180F, 0x180F }, { 0x181A, 0x181F }, { 0x1878, 0x187F },
+    { 0x18AB, 0x18AF }, { 0x18F6, 0x18FF }, { 0x191D, 0x191F },
+    { 0x192C, 0x192F }, { 0x193C, 0x193F }, { 0x1941, 0x1943 },
+    { 0x196E, 0x196F }, { 0x1975, 0x197F }, { 0x19AC, 0x19AF },
+    { 0x19CA, 0x19CF }, { 0x19DB, 0x19DD }, { 0x1A1C, 0x1A1D },
+    { 0x1A5F, 0x1A5F }, { 0x1A7D, 0x1A7E }, { 0x1A8A, 0x1A8F },
+    { 0x1A9A, 0x1A9F }, { 0x1AAE, 0x1AFF }, { 0x1B4C, 0x1B4F },
+    { 0x1B7D, 0x1B7F }, { 0x1BF4, 0x1BFB }, { 0x1C38, 0x1C3A },
+    { 0x1C4A, 0x1C4C }, { 0x1C80, 0x1CBF }, { 0x1CC8, 0x1CCF },
+    { 0x1CF7, 0x1CFF }, { 0x1DE7, 0x1DFB }, { 0x1F16, 0x1F17 },
+    { 0x1F1E, 0x1F1F }, { 0x1F46, 0x1F47 }, { 0x1F4E, 0x1F4F },
+    { 0x1F58, 0x1F58 }, { 0x1F5A, 0x1F5A }, { 0x1F5C, 0x1F5C },
+    { 0x1F5E, 0x1F5E }, { 0x1F7E, 0x1F7F }, { 0x1FB5, 0x1FB5 },
+    { 0x1FC5, 0x1FC5 }, { 0x1FD4, 0x1FD5 }, { 0x1FDC, 0x1FDC },
+    { 0x1FF0, 0x1FF1 }, { 0x1FF5, 0x1FF5 }, { 0x1FFF, 0x1FFF },
+    { 0x200B, 0x200F }, { 0x202A, 0x202E }, { 0x2060, 0x206F },
+    { 0x2072, 0x2073 }, { 0x208F, 0x208F }, { 0x209D, 0x209F },
+    { 0x20BB, 0x20CF }, { 0x20F1, 0x20FF }, { 0x218A, 0x218F },
+    { 0x23F4, 0x23FF }, { 0x2427, 0x243F }, { 0x244B, 0x245F },
+    { 0x2700, 0x2700 }, { 0x2B4D, 0x2B4F }, { 0x2B5A, 0x2BFF },
+    { 0x2C2F, 0x2C2F }, { 0x2C5F, 0x2C5F }, { 0x2CF4, 0x2CF8 },
+    { 0x2D26, 0x2D26 }, { 0x2D28, 0x2D2C }, { 0x2D2E, 0x2D2F },
+    { 0x2D68, 0x2D6E }, { 0x2D71, 0x2D7E }, { 0x2D97, 0x2D9F },
+    { 0x2DA7, 0x2DA7 }, { 0x2DAF, 0x2DAF }, { 0x2DB7, 0x2DB7 },
+    { 0x2DBF, 0x2DBF }, { 0x2DC7, 0x2DC7 }, { 0x2DCF, 0x2DCF },
+    { 0x2DD7, 0x2DD7 }, { 0x2DDF, 0x2DDF }, { 0x2E3C, 0x2E7F },
+    { 0x2E9A, 0x2E9A }, { 0x2EF4, 0x2EFF }, { 0x2FD6, 0x2FEF },
+    { 0x2FFC, 0x2FFF }, { 0x3040, 0x3040 }, { 0x3097, 0x3098 },
+    { 0x3100, 0x3104 }, { 0x312E, 0x3130 }, { 0x3164, 0x3164 },
+    { 0x318F, 0x318F }, { 0x31BB, 0x31BF }, { 0x31E4, 0x31EF },
+    { 0x321F, 0x321F }, { 0x32FF, 0x32FF }, { 0x4DB6, 0x4DBF },
+    { 0x9FCD, 0x9FFF }, { 0xA48D, 0xA48F }, { 0xA4C7, 0xA4CF },
+    { 0xA62C, 0xA63F }, { 0xA698, 0xA69E }, { 0xA6F8, 0xA6FF },
+    { 0xA78F, 0xA78F }, { 0xA794, 0xA79F }, { 0xA7AB, 0xA7F7 },
+    { 0xA82C, 0xA82F }, { 0xA83A, 0xA83F }, { 0xA878, 0xA87F },
+    { 0xA8C5, 0xA8CD }, { 0xA8DA, 0xA8DF }, { 0xA8FC, 0xA8FF },
+    { 0xA954, 0xA95E }, { 0xA97D, 0xA97F }, { 0xA9CE, 0xA9CE },
+    { 0xA9DA, 0xA9DD }, { 0xA9E0, 0xA9FF }, { 0xAA37, 0xAA3F },
+    { 0xAA4E, 0xAA4F }, { 0xAA5A, 0xAA5B }, { 0xAA7C, 0xAA7F },
+    { 0xAAC3, 0xAADA }, { 0xAAF7, 0xAB00 }, { 0xAB07, 0xAB08 },
+    { 0xAB0F, 0xAB10 }, { 0xAB17, 0xAB1F }, { 0xAB27, 0xAB27 },
+    { 0xAB2F, 0xABBF }, { 0xABEE, 0xABEF }, { 0xABFA, 0xABFF },
+    { 0xD7A4, 0xD7AF }, { 0xD7C7, 0xD7CA }, { 0xD7FC, 0xDFFF },
+    { 0xFA6E, 0xFA6F }, { 0xFADA, 0xFAFF }, { 0xFB07, 0xFB12 },
+    { 0xFB18, 0xFB1C }, { 0xFB37, 0xFB37 }, { 0xFB3D, 0xFB3D },
+    { 0xFB3F, 0xFB3F }, { 0xFB42, 0xFB42 }, { 0xFB45, 0xFB45 },
+    { 0xFBC2, 0xFBD2 }, { 0xFD40, 0xFD4F }, { 0xFD90, 0xFD91 },
+    { 0xFDC8, 0xFDEF }, { 0xFDFE, 0xFE0F }, { 0xFE1A, 0xFE1F },
+    { 0xFE27, 0xFE2F }, { 0xFE53, 0xFE53 }, { 0xFE67, 0xFE67 },
+    { 0xFE6C, 0xFE6F }, { 0xFE75, 0xFE75 }, { 0xFEFD, 0xFEFF },
+    { 0xFF00, 0xFF00 }, { 0xFFA0, 0xFFA0 }, { 0xFFBF, 0xFFC1 },
+    { 0xFFC8, 0xFFC9 }, { 0xFFD0, 0xFFD1 }, { 0xFFD8, 0xFFD9 },
+    { 0xFFDD, 0xFFDF }, { 0xFFE7, 0xFFE7 }, { 0xFFEF, 0xFFFB },
+    { 0xFFFE, 0xFFFF }, { 0x1000C, 0x1000C }, { 0x10027, 0x10027 },
+    { 0x1003B, 0x1003B }, { 0x1003E, 0x1003E }, { 0x1004E, 0x1004F },
+    { 0x1005E, 0x1007F }, { 0x100FB, 0x100FF }, { 0x10103, 0x10106 },
+    { 0x10134, 0x10136 }, { 0x1018B, 0x1018F }, { 0x1019C, 0x101CF },
+    { 0x101FE, 0x1027F }, { 0x1029D, 0x1029F }, { 0x102D1, 0x102FF },
+    { 0x1031F, 0x1031F }, { 0x10324, 0x1032F }, { 0x1034B, 0x1037F },
+    { 0x1039E, 0x1039E }, { 0x103C4, 0x103C7 }, { 0x103D6, 0x103FF },
+    { 0x1049E, 0x1049F }, { 0x104AA, 0x107FF }, { 0x10806, 0x10807 },
+    { 0x10809, 0x10809 }, { 0x10836, 0x10836 }, { 0x10839, 0x1083B },
+    { 0x1083D, 0x1083E }, { 0x10856, 0x10856 }, { 0x10860, 0x108FF },
+    { 0x1091C, 0x1091E }, { 0x1093A, 0x1093E }, { 0x10940, 0x1097F },
+    { 0x109B8, 0x109BD }, { 0x109C0, 0x109FF }, { 0x10A04, 0x10A04 },
+    { 0x10A07, 0x10A0B }, { 0x10A14, 0x10A14 }, { 0x10A18, 0x10A18 },
+    { 0x10A34, 0x10A37 }, { 0x10A3B, 0x10A3E }, { 0x10A48, 0x10A4F },
+    { 0x10A59, 0x10A5F }, { 0x10A80, 0x10AFF }, { 0x10B36, 0x10B38 },
+    { 0x10B56, 0x10B57 }, { 0x10B73, 0x10B77 }, { 0x10B80, 0x10BFF },
+    { 0x10C49, 0x10E5F }, { 0x10E7F, 0x10FFF }, { 0x1104E, 0x11051 },
+    { 0x11070, 0x1107F }, { 0x110BD, 0x110BD }, { 0x110C2, 0x110CF },
+    { 0x110E9, 0x110EF }, { 0x110FA, 0x110FF }, { 0x11135, 0x11135 },
+    { 0x11144, 0x1117F }, { 0x111C9, 0x111CF }, { 0x111DA, 0x1167F },
+    { 0x116B8, 0x116BF }, { 0x116CA, 0x11FFF }, { 0x1236F, 0x123FF },
+    { 0x12463, 0x1246F }, { 0x12474, 0x12FFF }, { 0x1342F, 0x167FF },
+    { 0x16A39, 0x16EFF }, { 0x16F45, 0x16F4F }, { 0x16F7F, 0x16F8E },
+    { 0x16FA0, 0x1AFFF }, { 0x1B002, 0x1CFFF }, { 0x1D0F6, 0x1D0FF },
+    { 0x1D127, 0x1D128 }, { 0x1D173, 0x1D17A }, { 0x1D1DE, 0x1D1FF },
+    { 0x1D246, 0x1D2FF }, { 0x1D357, 0x1D35F }, { 0x1D372, 0x1D3FF },
+    { 0x1D455, 0x1D455 }, { 0x1D49D, 0x1D49D }, { 0x1D4A0, 0x1D4A1 },
+    { 0x1D4A3, 0x1D4A4 }, { 0x1D4A7, 0x1D4A8 }, { 0x1D4AD, 0x1D4AD },
+    { 0x1D4BA, 0x1D4BA }, { 0x1D4BC, 0x1D4BC }, { 0x1D4C4, 0x1D4C4 },
+    { 0x1D506, 0x1D506 }, { 0x1D50B, 0x1D50C }, { 0x1D515, 0x1D515 },
+    { 0x1D51D, 0x1D51D }, { 0x1D53A, 0x1D53A }, { 0x1D53F, 0x1D53F },
+    { 0x1D545, 0x1D545 }, { 0x1D547, 0x1D549 }, { 0x1D551, 0x1D551 },
+    { 0x1D6A6, 0x1D6A7 }, { 0x1D7CC, 0x1D7CD }, { 0x1D800, 0x1EDFF },
+    { 0x1EE04, 0x1EE04 }, { 0x1EE20, 0x1EE20 }, { 0x1EE23, 0x1EE23 },
+    { 0x1EE25, 0x1EE26 }, { 0x1EE28, 0x1EE28 }, { 0x1EE33, 0x1EE33 },
+    { 0x1EE38, 0x1EE38 }, { 0x1EE3A, 0x1EE3A }, { 0x1EE3C, 0x1EE41 },
+    { 0x1EE43, 0x1EE46 }, { 0x1EE48, 0x1EE48 }, { 0x1EE4A, 0x1EE4A },
+    { 0x1EE4C, 0x1EE4C }, { 0x1EE50, 0x1EE50 }, { 0x1EE53, 0x1EE53 },
+    { 0x1EE55, 0x1EE56 }, { 0x1EE58, 0x1EE58 }, { 0x1EE5A, 0x1EE5A },
+    { 0x1EE5C, 0x1EE5C }, { 0x1EE5E, 0x1EE5E }, { 0x1EE60, 0x1EE60 },
+    { 0x1EE63, 0x1EE63 }, { 0x1EE65, 0x1EE66 }, { 0x1EE6B, 0x1EE6B },
+    { 0x1EE73, 0x1EE73 }, { 0x1EE78, 0x1EE78 }, { 0x1EE7D, 0x1EE7D },
+    { 0x1EE7F, 0x1EE7F }, { 0x1EE8A, 0x1EE8A }, { 0x1EE9C, 0x1EEA0 },
+    { 0x1EEA4, 0x1EEA4 }, { 0x1EEAA, 0x1EEAA }, { 0x1EEBC, 0x1EEEF },
+    { 0x1EEF2, 0x1EFFF }, { 0x1F02C, 0x1F02F }, { 0x1F094, 0x1F09F },
+    { 0x1F0AF, 0x1F0B0 }, { 0x1F0BF, 0x1F0C0 }, { 0x1F0D0, 0x1F0D0 },
+    { 0x1F0E0, 0x1F0FF }, { 0x1F10B, 0x1F10F }, { 0x1F12F, 0x1F12F },
+    { 0x1F16C, 0x1F16F }, { 0x1F19B, 0x1F1E5 }, { 0x1F203, 0x1F20F },
+    { 0x1F23B, 0x1F23F }, { 0x1F249, 0x1F24F }, { 0x1F252, 0x1F2FF },
+    { 0x1F321, 0x1F32F }, { 0x1F336, 0x1F336 }, { 0x1F37D, 0x1F37F },
+    { 0x1F394, 0x1F39F }, { 0x1F3C5, 0x1F3C5 }, { 0x1F3CB, 0x1F3DF },
+    { 0x1F3F1, 0x1F3FF }, { 0x1F43F, 0x1F43F }, { 0x1F441, 0x1F441 },
+    { 0x1F4F8, 0x1F4F8 }, { 0x1F4FD, 0x1F4FF }, { 0x1F53E, 0x1F53F },
+    { 0x1F544, 0x1F54F }, { 0x1F568, 0x1F5FA }, { 0x1F641, 0x1F644 },
+    { 0x1F650, 0x1F67F }, { 0x1F6C6, 0x1F6FF }, { 0x1F774, 0x1FFFF },
+    { 0x2A6D7, 0x2A6FF }, { 0x2B735, 0x2B73F }, { 0x2B81E, 0x2F7FF },
+    { 0x2FA1E, 0xF0000 }, { 0xFFFFE, 0xFFFFF }, { 0x10FFFE, 0x10FFFF }
+  };
+
+  return UCS >= 0 && UCS <= 0x10FFFF && !isCharInSet(UCS, NonPrintableRanges);
+}
+
+/// Gets the number of positions a character is likely to occupy when output
+/// on a terminal ("character width"). This depends on the implementation of the
+/// terminal, and there's no standard definition of character width.
+/// The implementation defines it in a way that is expected to be compatible
+/// with a generic Unicode-capable terminal.
+/// \return Character width:
+///   * ErrorNonPrintableCharacter (-1) for non-printable characters (as
+///     identified by isPrint);
+///   * 0 for non-spacing and enclosing combining marks;
+///   * 2 for CJK characters excluding halfwidth forms;
+///   * 1 for all remaining characters.
+static inline int charWidth(int UCS)
+{
+  if (!isPrint(UCS))
+    return ErrorNonPrintableCharacter;
+
+  // Sorted list of non-spacing and enclosing combining mark intervals as
+  // defined in "3.6 Combination" of
+  // http://www.unicode.org/versions/Unicode6.2.0/UnicodeStandard-6.2.pdf
+  static const UnicodeCharRange CombiningCharacters[] = {
+    { 0x0300, 0x036F }, { 0x0483, 0x0489 }, { 0x0591, 0x05BD },
+    { 0x05BF, 0x05BF }, { 0x05C1, 0x05C2 }, { 0x05C4, 0x05C5 },
+    { 0x05C7, 0x05C7 }, { 0x0610, 0x061A }, { 0x064B, 0x065F },
+    { 0x0670, 0x0670 }, { 0x06D6, 0x06DC }, { 0x06DF, 0x06E4 },
+    { 0x06E7, 0x06E8 }, { 0x06EA, 0x06ED }, { 0x0711, 0x0711 },
+    { 0x0730, 0x074A }, { 0x07A6, 0x07B0 }, { 0x07EB, 0x07F3 },
+    { 0x0816, 0x0819 }, { 0x081B, 0x0823 }, { 0x0825, 0x0827 },
+    { 0x0829, 0x082D }, { 0x0859, 0x085B }, { 0x08E4, 0x08FE },
+    { 0x0900, 0x0902 }, { 0x093A, 0x093A }, { 0x093C, 0x093C },
+    { 0x0941, 0x0948 }, { 0x094D, 0x094D }, { 0x0951, 0x0957 },
+    { 0x0962, 0x0963 }, { 0x0981, 0x0981 }, { 0x09BC, 0x09BC },
+    { 0x09C1, 0x09C4 }, { 0x09CD, 0x09CD }, { 0x09E2, 0x09E3 },
+    { 0x0A01, 0x0A02 }, { 0x0A3C, 0x0A3C }, { 0x0A41, 0x0A42 },
+    { 0x0A47, 0x0A48 }, { 0x0A4B, 0x0A4D }, { 0x0A51, 0x0A51 },
+    { 0x0A70, 0x0A71 }, { 0x0A75, 0x0A75 }, { 0x0A81, 0x0A82 },
+    { 0x0ABC, 0x0ABC }, { 0x0AC1, 0x0AC5 }, { 0x0AC7, 0x0AC8 },
+    { 0x0ACD, 0x0ACD }, { 0x0AE2, 0x0AE3 }, { 0x0B01, 0x0B01 },
+    { 0x0B3C, 0x0B3C }, { 0x0B3F, 0x0B3F }, { 0x0B41, 0x0B44 },
+    { 0x0B4D, 0x0B4D }, { 0x0B56, 0x0B56 }, { 0x0B62, 0x0B63 },
+    { 0x0B82, 0x0B82 }, { 0x0BC0, 0x0BC0 }, { 0x0BCD, 0x0BCD },
+    { 0x0C3E, 0x0C40 }, { 0x0C46, 0x0C48 }, { 0x0C4A, 0x0C4D },
+    { 0x0C55, 0x0C56 }, { 0x0C62, 0x0C63 }, { 0x0CBC, 0x0CBC },
+    { 0x0CBF, 0x0CBF }, { 0x0CC6, 0x0CC6 }, { 0x0CCC, 0x0CCD },
+    { 0x0CE2, 0x0CE3 }, { 0x0D41, 0x0D44 }, { 0x0D4D, 0x0D4D },
+    { 0x0D62, 0x0D63 }, { 0x0DCA, 0x0DCA }, { 0x0DD2, 0x0DD4 },
+    { 0x0DD6, 0x0DD6 }, { 0x0E31, 0x0E31 }, { 0x0E34, 0x0E3A },
+    { 0x0E47, 0x0E4E }, { 0x0EB1, 0x0EB1 }, { 0x0EB4, 0x0EB9 },
+    { 0x0EBB, 0x0EBC }, { 0x0EC8, 0x0ECD }, { 0x0F18, 0x0F19 },
+    { 0x0F35, 0x0F35 }, { 0x0F37, 0x0F37 }, { 0x0F39, 0x0F39 },
+    { 0x0F71, 0x0F7E }, { 0x0F80, 0x0F84 }, { 0x0F86, 0x0F87 },
+    { 0x0F8D, 0x0F97 }, { 0x0F99, 0x0FBC }, { 0x0FC6, 0x0FC6 },
+    { 0x102D, 0x1030 }, { 0x1032, 0x1037 }, { 0x1039, 0x103A },
+    { 0x103D, 0x103E }, { 0x1058, 0x1059 }, { 0x105E, 0x1060 },
+    { 0x1071, 0x1074 }, { 0x1082, 0x1082 }, { 0x1085, 0x1086 },
+    { 0x108D, 0x108D }, { 0x109D, 0x109D }, { 0x135D, 0x135F },
+    { 0x1712, 0x1714 }, { 0x1732, 0x1734 }, { 0x1752, 0x1753 },
+    { 0x1772, 0x1773 }, { 0x17B4, 0x17B5 }, { 0x17B7, 0x17BD },
+    { 0x17C6, 0x17C6 }, { 0x17C9, 0x17D3 }, { 0x17DD, 0x17DD },
+    { 0x180B, 0x180D }, { 0x18A9, 0x18A9 }, { 0x1920, 0x1922 },
+    { 0x1927, 0x1928 }, { 0x1932, 0x1932 }, { 0x1939, 0x193B },
+    { 0x1A17, 0x1A18 }, { 0x1A56, 0x1A56 }, { 0x1A58, 0x1A5E },
+    { 0x1A60, 0x1A60 }, { 0x1A62, 0x1A62 }, { 0x1A65, 0x1A6C },
+    { 0x1A73, 0x1A7C }, { 0x1A7F, 0x1A7F }, { 0x1B00, 0x1B03 },
+    { 0x1B34, 0x1B34 }, { 0x1B36, 0x1B3A }, { 0x1B3C, 0x1B3C },
+    { 0x1B42, 0x1B42 }, { 0x1B6B, 0x1B73 }, { 0x1B80, 0x1B81 },
+    { 0x1BA2, 0x1BA5 }, { 0x1BA8, 0x1BA9 }, { 0x1BAB, 0x1BAB },
+    { 0x1BE6, 0x1BE6 }, { 0x1BE8, 0x1BE9 }, { 0x1BED, 0x1BED },
+    { 0x1BEF, 0x1BF1 }, { 0x1C2C, 0x1C33 }, { 0x1C36, 0x1C37 },
+    { 0x1CD0, 0x1CD2 }, { 0x1CD4, 0x1CE0 }, { 0x1CE2, 0x1CE8 },
+    { 0x1CED, 0x1CED }, { 0x1CF4, 0x1CF4 }, { 0x1DC0, 0x1DE6 },
+    { 0x1DFC, 0x1DFF }, { 0x20D0, 0x20F0 }, { 0x2CEF, 0x2CF1 },
+    { 0x2D7F, 0x2D7F }, { 0x2DE0, 0x2DFF }, { 0x302A, 0x302D },
+    { 0x3099, 0x309A }, { 0xA66F, 0xA672 }, { 0xA674, 0xA67D },
+    { 0xA69F, 0xA69F }, { 0xA6F0, 0xA6F1 }, { 0xA802, 0xA802 },
+    { 0xA806, 0xA806 }, { 0xA80B, 0xA80B }, { 0xA825, 0xA826 },
+    { 0xA8C4, 0xA8C4 }, { 0xA8E0, 0xA8F1 }, { 0xA926, 0xA92D },
+    { 0xA947, 0xA951 }, { 0xA980, 0xA982 }, { 0xA9B3, 0xA9B3 },
+    { 0xA9B6, 0xA9B9 }, { 0xA9BC, 0xA9BC }, { 0xAA29, 0xAA2E },
+    { 0xAA31, 0xAA32 }, { 0xAA35, 0xAA36 }, { 0xAA43, 0xAA43 },
+    { 0xAA4C, 0xAA4C }, { 0xAAB0, 0xAAB0 }, { 0xAAB2, 0xAAB4 },
+    { 0xAAB7, 0xAAB8 }, { 0xAABE, 0xAABF }, { 0xAAC1, 0xAAC1 },
+    { 0xAAEC, 0xAAED }, { 0xAAF6, 0xAAF6 }, { 0xABE5, 0xABE5 },
+    { 0xABE8, 0xABE8 }, { 0xABED, 0xABED }, { 0xFB1E, 0xFB1E },
+    { 0xFE00, 0xFE0F }, { 0xFE20, 0xFE26 }, { 0x101FD, 0x101FD },
+    { 0x10A01, 0x10A03 }, { 0x10A05, 0x10A06 }, { 0x10A0C, 0x10A0F },
+    { 0x10A38, 0x10A3A }, { 0x10A3F, 0x10A3F }, { 0x11001, 0x11001 },
+    { 0x11038, 0x11046 }, { 0x11080, 0x11081 }, { 0x110B3, 0x110B6 },
+    { 0x110B9, 0x110BA }, { 0x11100, 0x11102 }, { 0x11127, 0x1112B },
+    { 0x1112D, 0x11134 }, { 0x11180, 0x11181 }, { 0x111B6, 0x111BE },
+    { 0x116AB, 0x116AB }, { 0x116AD, 0x116AD }, { 0x116B0, 0x116B5 },
+    { 0x116B7, 0x116B7 }, { 0x16F8F, 0x16F92 }, { 0x1D167, 0x1D169 },
+    { 0x1D17B, 0x1D182 }, { 0x1D185, 0x1D18B }, { 0x1D1AA, 0x1D1AD },
+    { 0x1D242, 0x1D244 }, { 0xE0100, 0xE01EF },
+  };
+
+  if (isCharInSet(UCS, CombiningCharacters))
+    return 0;
+
+  static const UnicodeCharRange DoubleWidthCharacters[] = {
+    // Hangul Jamo
+    { 0x1100, 0x11FF },
+    // Deprecated fullwidth angle brackets
+    { 0x2329, 0x232A },
+    // CJK Misc, CJK Unified Ideographs, Yijing Hexagrams, Yi
+    // excluding U+303F (IDEOGRAPHIC HALF FILL SPACE)
+    { 0x2E80, 0x303E }, { 0x3040, 0xA4CF },
+    // Hangul
+    { 0xAC00, 0xD7A3 }, { 0xD7B0, 0xD7C6 }, { 0xD7CB, 0xD7FB },
+    // CJK Unified Ideographs
+    { 0xF900, 0xFAFF },
+    // Vertical forms
+    { 0xFE10, 0xFE19 },
+    // CJK Compatibility Forms + Small Form Variants
+    { 0xFE30, 0xFE6F },
+    // Fullwidth forms
+    { 0xFF01, 0xFF60 }, { 0xFFE0, 0xFFE6 },
+    // CJK Unified Ideographs
+    { 0x20000, 0x2A6DF }, { 0x2A700, 0x2B81F }, { 0x2F800, 0x2FA1F }
+  };
+
+  if (isCharInSet(UCS, DoubleWidthCharacters))
+    return 2;
+  return 1;
 }
 
-bool isPrint(int c) {
-    return iswprint(c);
+int columnWidth(StringRef Text) {
+  unsigned ColumnWidth = 0;
+  unsigned Length;
+  for (size_t i = 0, e = Text.size(); i < e; i += Length) {
+    Length = getNumBytesForUTF8(Text[i]);
+    if (Length <= 0 || i + Length > Text.size())
+      return ErrorInvalidUTF8;
+    UTF32 buf[1];
+    const UTF8 *Start = reinterpret_cast<const UTF8 *>(Text.data() + i);
+    UTF32 *Target = &buf[0];
+    if (conversionOK != ConvertUTF8toUTF32(&Start, Start + Length, &Target,
+                                           Target + 1, strictConversion))
+      return ErrorInvalidUTF8;
+    int Width = charWidth(buf[0]);
+    if (Width < 0)
+      return ErrorNonPrintableCharacter;
+    ColumnWidth += Width;
+  }
+  return ColumnWidth;
 }
 
 }