Check in the pristine copy of ICU 4.6...

icu46/source/tools/gennorm2/n2builder.cpp

+/*
+*******************************************************************************
+*
+*   Copyright (C) 2009-2010, International Business Machines
+*   Corporation and others.  All Rights Reserved.
+*
+*******************************************************************************
+*   file name:  n2builder.cpp
+*   encoding:   US-ASCII
+*   tab size:   8 (not used)
+*   indentation:4
+*
+*   created on: 2009nov25
+*   created by: Markus W. Scherer
+*
+* Builds Normalizer2 data and writes a binary .nrm file.
+* For the file format see source/common/normalizer2impl.h.
+*/
+
+#include "unicode/utypes.h"
+#include "n2builder.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#if U_HAVE_STD_STRING
+#include <vector>
+#endif
+#include "unicode/errorcode.h"
+#include "unicode/localpointer.h"
+#include "unicode/putil.h"
+#include "unicode/udata.h"
+#include "unicode/uniset.h"
+#include "unicode/unistr.h"
+#include "unicode/ustring.h"
+#include "hash.h"
+#include "normalizer2impl.h"
+#include "toolutil.h"
+#include "unewdata.h"
+#include "utrie2.h"
+#include "uvectr32.h"
+
+#define LENGTHOF(array) (int32_t)(sizeof(array)/sizeof((array)[0]))
+
+#if !UCONFIG_NO_NORMALIZATION
+
+/* UDataInfo cf. udata.h */
+static UDataInfo dataInfo={
+    sizeof(UDataInfo),
+    0,
+
+    U_IS_BIG_ENDIAN,
+    U_CHARSET_FAMILY,
+    U_SIZEOF_UCHAR,
+    0,
+
+    { 0x4e, 0x72, 0x6d, 0x32 }, /* dataFormat="Nrm2" */
+    { 1, 0, 0, 0 },             /* formatVersion */
+    { 5, 2, 0, 0 }              /* dataVersion (Unicode version) */
+};
+
+U_NAMESPACE_BEGIN
+
+class HangulIterator {
+public:
+    struct Range {
+        UChar32 start, limit;
+        uint16_t norm16;
+    };
+
+    HangulIterator() : rangeIndex(0) {}
+    const Range *nextRange() {
+        if(rangeIndex<LENGTHOF(ranges)) {
+            return ranges+rangeIndex++;
+        } else {
+            return NULL;
+        }
+    }
+    void reset() { rangeIndex=0; }
+private:
+    static const Range ranges[4];
+    int32_t rangeIndex;
+};
+
+const HangulIterator::Range HangulIterator::ranges[4]={
+    { Hangul::JAMO_L_BASE, Hangul::JAMO_L_BASE+Hangul::JAMO_L_COUNT, 1 },
+    { Hangul::JAMO_V_BASE, Hangul::JAMO_V_BASE+Hangul::JAMO_V_COUNT, Normalizer2Impl::JAMO_VT },
+    // JAMO_T_BASE+1: not U+11A7
+    { Hangul::JAMO_T_BASE+1, Hangul::JAMO_T_BASE+Hangul::JAMO_T_COUNT, Normalizer2Impl::JAMO_VT },
+    { Hangul::HANGUL_BASE, Hangul::HANGUL_BASE+Hangul::HANGUL_COUNT, 0 },  // will become minYesNo
+};
+
+struct CompositionPair {
+    CompositionPair(UChar32 t, UChar32 c) : trail(t), composite(c) {}
+    UChar32 trail, composite;
+};
+
+struct Norm {
+    enum MappingType { NONE, REMOVED, ROUND_TRIP, ONE_WAY };
+
+    UBool hasMapping() const { return mappingType>REMOVED; }
+
+    // Requires hasMapping() and well-formed mapping.
+    void setMappingCP() {
+        UChar32 c;
+        if(!mapping->isEmpty() && mapping->length()==U16_LENGTH(c=mapping->char32At(0))) {
+            mappingCP=c;
+        } else {
+            mappingCP=U_SENTINEL;
+        }
+    }
+
+    const CompositionPair *getCompositionPairs(int32_t &length) const {
+        if(compositions==NULL) {
+            length=0;
+            return NULL;
+        } else {
+            length=compositions->size()/2;
+            return reinterpret_cast<const CompositionPair *>(compositions->getBuffer());
+        }
+    }
+
+    UnicodeString *mapping;
+    UChar32 mappingCP;  // >=0 if mapping to 1 code point
+    int32_t mappingPhase;
+    MappingType mappingType;
+
+    UVector32 *compositions;  // (trail, composite) pairs
+    uint8_t cc;
+    UBool combinesBack;
+    UBool hasNoCompBoundaryAfter;
+
+    enum OffsetType {
+        OFFSET_NONE, OFFSET_MAYBE_YES,
+        OFFSET_YES_YES, OFFSET_YES_NO, OFFSET_NO_NO,
+        OFFSET_DELTA
+    };
+    enum { OFFSET_SHIFT=4, OFFSET_MASK=(1<<OFFSET_SHIFT)-1 };
+    int32_t offset;
+};
+
+class Normalizer2DBEnumerator {
+public:
+    Normalizer2DBEnumerator(Normalizer2DataBuilder &b) : builder(b) {}
+    virtual ~Normalizer2DBEnumerator() {}
+    virtual UBool rangeHandler(UChar32 start, UChar32 end, uint32_t value) = 0;
+    Normalizer2DBEnumerator *ptr() { return this; }
+protected:
+    Normalizer2DataBuilder &builder;
+};
+
+U_CDECL_BEGIN
+
+static UBool U_CALLCONV
+enumRangeHandler(const void *context, UChar32 start, UChar32 end, uint32_t value) {
+    return ((Normalizer2DBEnumerator *)context)->rangeHandler(start, end, value);
+}
+
+U_CDECL_END
+
+Normalizer2DataBuilder::Normalizer2DataBuilder(UErrorCode &errorCode) :
+        phase(0), overrideHandling(OVERRIDE_PREVIOUS), optimization(OPTIMIZE_NORMAL) {
+    memset(unicodeVersion, 0, sizeof(unicodeVersion));
+    normTrie=utrie2_open(0, 0, &errorCode);
+    normMem=utm_open("gennorm2 normalization structs", 10000, 0x110100, sizeof(Norm));
+    norms=allocNorm();  // unused Norm struct at index 0
+    memset(indexes, 0, sizeof(indexes));
+}
+
+Normalizer2DataBuilder::~Normalizer2DataBuilder() {
+    utrie2_close(normTrie);
+    int32_t normsLength=utm_countItems(normMem);
+    for(int32_t i=1; i<normsLength; ++i) {
+        delete norms[i].mapping;
+        delete norms[i].compositions;
+    }
+    utm_close(normMem);
+    utrie2_close(norm16Trie);
+}
+
+void
+Normalizer2DataBuilder::setUnicodeVersion(const char *v) {
+    u_versionFromString(unicodeVersion, v);
+}
+
+Norm *Normalizer2DataBuilder::allocNorm() {
+    Norm *p=(Norm *)utm_alloc(normMem);
+    norms=(Norm *)utm_getStart(normMem);  // in case it got reallocated
+    return p;
+}
+
+/* get an existing Norm unit */
+Norm *Normalizer2DataBuilder::getNorm(UChar32 c) {
+    uint32_t i=utrie2_get32(normTrie, c);
+    if(i==0) {
+        return NULL;
+    }
+    return norms+i;
+}
+
+const Norm &Normalizer2DataBuilder::getNormRef(UChar32 c) const {
+    return norms[utrie2_get32(normTrie, c)];
+}
+
+/*
+ * get or create a Norm unit;
+ * get or create the intermediate trie entries for it as well
+ */
+Norm *Normalizer2DataBuilder::createNorm(UChar32 c) {
+    uint32_t i=utrie2_get32(normTrie, c);
+    if(i!=0) {
+        return norms+i;
+    } else {
+        /* allocate Norm */
+        Norm *p=allocNorm();
+        IcuToolErrorCode errorCode("gennorm2/createNorm()");
+        utrie2_set32(normTrie, c, (uint32_t)(p-norms), errorCode);
+        return p;
+    }
+}
+
+Norm *Normalizer2DataBuilder::checkNormForMapping(Norm *p, UChar32 c) {
+    if(p!=NULL) {
+        if(p->mappingType!=Norm::NONE) {
+            if( overrideHandling==OVERRIDE_NONE ||
+                (overrideHandling==OVERRIDE_PREVIOUS && p->mappingPhase==phase)
+            ) {
+                fprintf(stderr,
+                        "error in gennorm2 phase %d: "
+                        "not permitted to override mapping for U+%04lX from phase %d\n",
+                        (int)phase, (long)c, (int)p->mappingPhase);
+                exit(U_INVALID_FORMAT_ERROR);
+            }
+            delete p->mapping;
+            p->mapping=NULL;
+        }
+        p->mappingPhase=phase;
+    }
+    return p;
+}
+
+void Normalizer2DataBuilder::setOverrideHandling(OverrideHandling oh) {
+    overrideHandling=oh;
+    ++phase;
+}
+
+void Normalizer2DataBuilder::setCC(UChar32 c, uint8_t cc) {
+    createNorm(c)->cc=cc;
+}
+
+uint8_t Normalizer2DataBuilder::getCC(UChar32 c) const {
+    return getNormRef(c).cc;
+}
+
+static UBool isWellFormed(const UnicodeString &s) {
+    UErrorCode errorCode=U_ZERO_ERROR;
+    u_strToUTF8(NULL, 0, NULL, s.getBuffer(), s.length(), &errorCode);
+    return U_SUCCESS(errorCode) || errorCode==U_BUFFER_OVERFLOW_ERROR;
+}
+
+void Normalizer2DataBuilder::setOneWayMapping(UChar32 c, const UnicodeString &m) {
+    if(!isWellFormed(m)) {
+        fprintf(stderr,
+                "error in gennorm2 phase %d: "
+                "illegal one-way mapping from U+%04lX to malformed string\n",
+                (int)phase, (long)c);
+        exit(U_INVALID_FORMAT_ERROR);
+    }
+    Norm *p=checkNormForMapping(createNorm(c), c);
+    p->mapping=new UnicodeString(m);
+    p->mappingType=Norm::ONE_WAY;
+    p->setMappingCP();
+}
+
+void Normalizer2DataBuilder::setRoundTripMapping(UChar32 c, const UnicodeString &m) {
+    if(U_IS_SURROGATE(c)) {
+        fprintf(stderr,
+                "error in gennorm2 phase %d: "
+                "illegal round-trip mapping from surrogate code point U+%04lX\n",
+                (int)phase, (long)c);
+        exit(U_INVALID_FORMAT_ERROR);
+    }
+    if(!isWellFormed(m)) {
+        fprintf(stderr,
+                "error in gennorm2 phase %d: "
+                "illegal round-trip mapping from U+%04lX to malformed string\n",
+                (int)phase, (long)c);
+        exit(U_INVALID_FORMAT_ERROR);
+    }
+    int32_t numCP=u_countChar32(m.getBuffer(), m.length());
+    if(numCP!=2) {
+        fprintf(stderr,
+                "error in gennorm2 phase %d: "
+                "illegal round-trip mapping from U+%04lX to %d!=2 code points\n",
+                (int)phase, (long)c, (int)numCP);
+        exit(U_INVALID_FORMAT_ERROR);
+    }
+    Norm *p=checkNormForMapping(createNorm(c), c);
+    p->mapping=new UnicodeString(m);
+    p->mappingType=Norm::ROUND_TRIP;
+    p->mappingCP=U_SENTINEL;
+}
+
+void Normalizer2DataBuilder::removeMapping(UChar32 c) {
+    Norm *p=checkNormForMapping(getNorm(c), c);
+    if(p!=NULL) {
+        p->mappingType=Norm::REMOVED;
+    }
+}
+
+class CompositionBuilder : public Normalizer2DBEnumerator {
+public:
+    CompositionBuilder(Normalizer2DataBuilder &b) : Normalizer2DBEnumerator(b) {}
+    virtual UBool rangeHandler(UChar32 start, UChar32 end, uint32_t value) {
+        builder.addComposition(start, end, value);
+        return TRUE;
+    }
+};
+
+void
+Normalizer2DataBuilder::addComposition(UChar32 start, UChar32 end, uint32_t value) {
+    if(norms[value].mappingType==Norm::ROUND_TRIP) {
+        if(start!=end) {
+            fprintf(stderr,
+                    "gennorm2 error: same round-trip mapping for "
+                    "more than 1 code point U+%04lX..U+%04lX\n",
+                    (long)start, (long)end);
+            exit(U_INVALID_FORMAT_ERROR);
+        }
+        if(norms[value].cc!=0) {
+            fprintf(stderr,
+                    "gennorm2 error: "
+                    "U+%04lX has a round-trip mapping and ccc!=0, "
+                    "not possible in Unicode normalization\n",
+                    (long)start);
+            exit(U_INVALID_FORMAT_ERROR);
+        }
+        // setRoundTripMapping() ensured that there are exactly two code points.
+        const UnicodeString &m=*norms[value].mapping;
+        UChar32 lead=m.char32At(0);
+        UChar32 trail=m.char32At(m.length()-1);
+        if(getCC(lead)!=0) {
+            fprintf(stderr,
+                    "gennorm2 error: "
+                    "U+%04lX's round-trip mapping's starter U+%04lX has ccc!=0, "
+                    "not possible in Unicode normalization\n",
+                    (long)start, (long)lead);
+            exit(U_INVALID_FORMAT_ERROR);
+        }
+        // Flag for trailing character.
+        createNorm(trail)->combinesBack=TRUE;
+        // Insert (trail, composite) pair into compositions list for the lead character.
+        IcuToolErrorCode errorCode("gennorm2/addComposition()");
+        Norm *leadNorm=createNorm(lead);
+        UVector32 *compositions=leadNorm->compositions;
+        int32_t i;
+        if(compositions==NULL) {
+            compositions=leadNorm->compositions=new UVector32(errorCode);
+            i=0;  // "insert" the first pair at index 0
+        } else {
+            // Insertion sort, and check for duplicate trail characters.
+            int32_t length;
+            const CompositionPair *pairs=leadNorm->getCompositionPairs(length);
+            for(i=0; i<length; ++i) {
+                if(trail==pairs[i].trail) {
+                    fprintf(stderr,
+                            "gennorm2 error: same round-trip mapping for "
+                            "more than 1 code point (e.g., U+%04lX) to U+%04lX + U+%04lX\n",
+                            (long)start, (long)lead, (long)trail);
+                    exit(U_INVALID_FORMAT_ERROR);
+                }
+                if(trail<pairs[i].trail) {
+                    break;
+                }
+            }
+        }
+        compositions->insertElementAt(trail, 2*i, errorCode);
+        compositions->insertElementAt(start, 2*i+1, errorCode);
+    }
+}
+
+UBool Normalizer2DataBuilder::combinesWithCCBetween(const Norm &norm,
+                                                    uint8_t lowCC, uint8_t highCC) const {
+    if((highCC-lowCC)>=2) {
+        int32_t length;
+        const CompositionPair *pairs=norm.getCompositionPairs(length);
+        for(int32_t i=0; i<length; ++i) {
+            uint8_t trailCC=getCC(pairs[i].trail);
+            if(lowCC<trailCC && trailCC<highCC) {
+                return TRUE;
+            }
+        }
+    }
+    return FALSE;
+}
+
+UChar32 Normalizer2DataBuilder::combine(const Norm &norm, UChar32 trail) const {
+    int32_t length;
+    const CompositionPair *pairs=norm.getCompositionPairs(length);
+    for(int32_t i=0; i<length; ++i) {
+        if(trail==pairs[i].trail) {
+            return pairs[i].composite;
+        }
+        if(trail<pairs[i].trail) {
+            break;
+        }
+    }
+    return U_SENTINEL;
+}
+
+class Decomposer : public Normalizer2DBEnumerator {
+public:
+    Decomposer(Normalizer2DataBuilder &b) : Normalizer2DBEnumerator(b), didDecompose(FALSE) {}
+    virtual UBool rangeHandler(UChar32 start, UChar32 end, uint32_t value) {
+        didDecompose|=builder.decompose(start, end, value);
+        return TRUE;
+    }
+    UBool didDecompose;
+};
+
+UBool
+Normalizer2DataBuilder::decompose(UChar32 start, UChar32 end, uint32_t value) {
+    if(norms[value].hasMapping()) {
+        const UnicodeString &m=*norms[value].mapping;
+        UnicodeString *decomposed=NULL;
+        const UChar *s=m.getBuffer();
+        int32_t length=m.length();
+        int32_t prev, i=0;
+        UChar32 c;
+        while(i<length) {
+            prev=i;
+            U16_NEXT(s, i, length, c);
+            if(start<=c && c<=end) {
+                fprintf(stderr,
+                        "gennorm2 error: U+%04lX maps to itself directly or indirectly\n",
+                        (long)c);
+                exit(U_INVALID_FORMAT_ERROR);
+            }
+            const Norm &cNorm=getNormRef(c);
+            if(cNorm.hasMapping()) {
+                if(norms[value].mappingType==Norm::ROUND_TRIP) {
+                    if(prev==0) {
+                        if(cNorm.mappingType!=Norm::ROUND_TRIP) {
+                            fprintf(stderr,
+                                    "gennorm2 error: "
+                                    "U+%04lX's round-trip mapping's starter "
+                                    "U+%04lX one-way-decomposes, "
+                                    "not possible in Unicode normalization\n",
+                                    (long)start, (long)c);
+                            exit(U_INVALID_FORMAT_ERROR);
+                        }
+                        uint8_t myTrailCC=getCC(m.char32At(i));
+                        UChar32 cTrailChar=cNorm.mapping->char32At(cNorm.mapping->length()-1);
+                        uint8_t cTrailCC=getCC(cTrailChar);
+                        if(cTrailCC>myTrailCC) {
+                            fprintf(stderr,
+                                    "gennorm2 error: "
+                                    "U+%04lX's round-trip mapping's starter "
+                                    "U+%04lX decomposes and the "
+                                    "inner/earlier tccc=%hu > outer/following tccc=%hu, "
+                                    "not possible in Unicode normalization\n",
+                                    (long)start, (long)c,
+                                    (short)cTrailCC, (short)myTrailCC);
+                            exit(U_INVALID_FORMAT_ERROR);
+                        }
+                    } else {
+                        fprintf(stderr,
+                                "gennorm2 error: "
+                                "U+%04lX's round-trip mapping's non-starter "
+                                "U+%04lX decomposes, "
+                                "not possible in Unicode normalization\n",
+                                (long)start, (long)c);
+                        exit(U_INVALID_FORMAT_ERROR);
+                    }
+                }
+                if(decomposed==NULL) {
+                    decomposed=new UnicodeString(m, 0, prev);
+                }
+                decomposed->append(*cNorm.mapping);
+            } else if(Hangul::isHangul(c)) {
+                UChar buffer[3];
+                int32_t hangulLength=Hangul::decompose(c, buffer);
+                if(norms[value].mappingType==Norm::ROUND_TRIP && prev!=0) {
+                    fprintf(stderr,
+                            "gennorm2 error: "
+                            "U+%04lX's round-trip mapping's non-starter "
+                            "U+%04lX decomposes, "
+                            "not possible in Unicode normalization\n",
+                            (long)start, (long)c);
+                    exit(U_INVALID_FORMAT_ERROR);
+                }
+                if(decomposed==NULL) {
+                    decomposed=new UnicodeString(m, 0, prev);
+                }
+                decomposed->append(buffer, hangulLength);
+            } else if(decomposed!=NULL) {
+                decomposed->append(m, prev, i-prev);
+            }
+        }
+        if(decomposed!=NULL) {
+            delete norms[value].mapping;
+            norms[value].mapping=decomposed;
+            // Not  norms[value].setMappingCP();  because the original mapping
+            // is most likely to be encodable as a delta.
+            return TRUE;
+        }
+    }
+    return FALSE;
+}
+
+class BuilderReorderingBuffer {
+public:
+    BuilderReorderingBuffer() : fLength(0), fLastStarterIndex(-1), fDidReorder(FALSE) {}
+    void reset() {
+        fLength=0;
+        fLastStarterIndex=-1;
+        fDidReorder=FALSE;
+    }
+    int32_t length() const { return fLength; }
+    UBool isEmpty() const { return fLength==0; }
+    int32_t lastStarterIndex() const { return fLastStarterIndex; }
+    UChar32 charAt(int32_t i) const { return fArray[i]>>8; }
+    uint8_t ccAt(int32_t i) const { return (uint8_t)fArray[i]; }
+    UBool didReorder() const { return fDidReorder; }
+    void append(UChar32 c, uint8_t cc) {
+        if(cc==0 || fLength==0 || ccAt(fLength-1)<=cc) {
+            if(cc==0) {
+                fLastStarterIndex=fLength;
+            }
+            fArray[fLength++]=(c<<8)|cc;
+            return;
+        }
+        // Let this character bubble back to its canonical order.
+        int32_t i=fLength-1;
+        while(i>fLastStarterIndex && ccAt(i)>cc) {
+            --i;
+        }
+        ++i;  // after the last starter or prevCC<=cc
+        // Move this and the following characters forward one to make space.
+        for(int32_t j=fLength; i<j; --j) {
+            fArray[j]=fArray[j-1];
+        }
+        fArray[i]=(c<<8)|cc;
+        ++fLength;
+        fDidReorder=TRUE;
+    }
+    void toString(UnicodeString &dest) {
+        dest.remove();
+        for(int32_t i=0; i<fLength; ++i) {
+            dest.append(charAt(i));
+        }
+    }
+    void setComposite(UChar32 composite, int32_t combMarkIndex) {
+        fArray[fLastStarterIndex]=composite<<8;
+        // Remove the combining mark that contributed to the composite.
+        --fLength;
+        while(combMarkIndex<fLength) {
+            fArray[combMarkIndex]=fArray[combMarkIndex+1];
+            ++combMarkIndex;
+        }
+    }
+private:
+    int32_t fArray[Normalizer2Impl::MAPPING_LENGTH_MASK];
+    int32_t fLength;
+    int32_t fLastStarterIndex;
+    UBool fDidReorder;
+};
+
+void
+Normalizer2DataBuilder::reorder(Norm *p, BuilderReorderingBuffer &buffer) {
+    UnicodeString &m=*p->mapping;
+    int32_t length=m.length();
+    if(length>Normalizer2Impl::MAPPING_LENGTH_MASK) {
+        return;  // writeMapping() will complain about it and print the code point.
+    }
+    const UChar *s=m.getBuffer();
+    int32_t i=0;
+    UChar32 c;
+    while(i<length) {
+        U16_NEXT(s, i, length, c);
+        buffer.append(c, getCC(c));
+    }
+    if(buffer.didReorder()) {
+        buffer.toString(m);
+    }
+}
+
+UBool Normalizer2DataBuilder::hasNoCompBoundaryAfter(BuilderReorderingBuffer &buffer) {
+    if(buffer.isEmpty()) {
+        return TRUE;  // maps-to-empty string is no boundary of any kind
+    }
+    int32_t lastStarterIndex=buffer.lastStarterIndex();
+    if(lastStarterIndex<0) {
+        return TRUE;  // no starter
+    }
+    UChar32 starter=buffer.charAt(lastStarterIndex);
+    if( Hangul::isJamoL(starter) ||
+        (Hangul::isJamoV(starter) &&
+         0<lastStarterIndex && Hangul::isJamoL(buffer.charAt(lastStarterIndex-1)))
+    ) {
+        // A Jamo leading consonant or an LV pair combines-forward if it is at the end,
+        // otherwise it is blocked.
+        return lastStarterIndex==buffer.length()-1;
+    }
+    // no Hangul in fully decomposed mapping
+    const Norm *starterNorm=&getNormRef(starter);
+    if(starterNorm->compositions==NULL) {
+        return FALSE;  // the last starter does not combine forward
+    }
+    // Compose as far as possible, and see if further compositions are possible.
+    uint8_t prevCC=0;
+    for(int32_t combMarkIndex=lastStarterIndex+1; combMarkIndex<buffer.length();) {
+        uint8_t cc=buffer.ccAt(combMarkIndex);  // !=0 because after last starter
+        if(combinesWithCCBetween(*starterNorm, prevCC, cc)) {
+            return TRUE;
+        }
+        if( prevCC<cc &&
+            (starter=combine(*starterNorm, buffer.charAt(combMarkIndex)))>=0
+        ) {
+            buffer.setComposite(starter, combMarkIndex);
+            starterNorm=&getNormRef(starter);
+            if(starterNorm->compositions==NULL) {
+                return FALSE;  // the composite does not combine further
+            }
+        } else {
+            prevCC=cc;
+            ++combMarkIndex;
+        }
+    }
+    // TRUE if the final, forward-combining starter is at the end.
+    return prevCC==0;
+}
+
+// Requires p->hasMapping().
+void Normalizer2DataBuilder::writeMapping(UChar32 c, const Norm *p, UnicodeString &dataString) {
+    UnicodeString &m=*p->mapping;
+    int32_t length=m.length();
+    if(length>Normalizer2Impl::MAPPING_LENGTH_MASK) {
+        fprintf(stderr,
+                "gennorm2 error: "
+                "mapping for U+%04lX longer than maximum of %d\n",
+                (long)c, Normalizer2Impl::MAPPING_LENGTH_MASK);
+        exit(U_INVALID_FORMAT_ERROR);
+    }
+    int32_t leadCC, trailCC;
+    if(length==0) {
+        leadCC=trailCC=0;
+    } else {
+        leadCC=getCC(m.char32At(0));
+        trailCC=getCC(m.char32At(length-1));
+    }
+    if(c<Normalizer2Impl::MIN_CCC_LCCC_CP && (p->cc!=0 || leadCC!=0)) {
+        fprintf(stderr,
+                "gennorm2 error: "
+                "U+%04lX below U+0300 has ccc!=0 or lccc!=0, not supported by ICU\n",
+                (long)c);
+        exit(U_INVALID_FORMAT_ERROR);
+    }
+    int32_t firstUnit=length|(trailCC<<8);
+    int32_t secondUnit=p->cc|(leadCC<<8);
+    if(secondUnit!=0) {
+        firstUnit|=Normalizer2Impl::MAPPING_HAS_CCC_LCCC_WORD;
+    }
+    if(p->compositions!=NULL) {
+        firstUnit|=Normalizer2Impl::MAPPING_PLUS_COMPOSITION_LIST;
+    }
+    if(p->hasNoCompBoundaryAfter) {
+        firstUnit|=Normalizer2Impl::MAPPING_NO_COMP_BOUNDARY_AFTER;
+    }
+    dataString.append((UChar)firstUnit);
+    if(secondUnit!=0) {
+        dataString.append((UChar)secondUnit);
+    }
+    dataString.append(m);
+}
+
+// Requires p->compositions!=NULL.
+void Normalizer2DataBuilder::writeCompositions(UChar32 c, const Norm *p, UnicodeString &dataString) {
+    if(p->cc!=0) {
+        fprintf(stderr,
+                "gennorm2 error: "
+                "U+%04lX combines-forward and has ccc!=0, not possible in Unicode normalization\n",
+                (long)c);
+        exit(U_INVALID_FORMAT_ERROR);
+    }
+    int32_t length;
+    const CompositionPair *pairs=p->getCompositionPairs(length);
+    for(int32_t i=0; i<length; ++i) {
+        const CompositionPair &pair=pairs[i];
+        // 22 bits for the composite character and whether it combines forward.
+        UChar32 compositeAndFwd=pair.composite<<1;
+        if(getNormRef(pair.composite).compositions!=NULL) {
+            compositeAndFwd|=1;  // The composite character also combines-forward.
+        }
+        // Encode most pairs in two units and some in three.
+        int32_t firstUnit, secondUnit, thirdUnit;
+        if(pair.trail<Normalizer2Impl::COMP_1_TRAIL_LIMIT) {
+            if(compositeAndFwd<=0xffff) {
+                firstUnit=pair.trail<<1;
+                secondUnit=compositeAndFwd;
+                thirdUnit=-1;
+            } else {
+                firstUnit=(pair.trail<<1)|Normalizer2Impl::COMP_1_TRIPLE;
+                secondUnit=compositeAndFwd>>16;
+                thirdUnit=compositeAndFwd;
+            }
+        } else {
+            firstUnit=(Normalizer2Impl::COMP_1_TRAIL_LIMIT+
+                       (pair.trail>>Normalizer2Impl::COMP_1_TRAIL_SHIFT))|
+                      Normalizer2Impl::COMP_1_TRIPLE;
+            secondUnit=(pair.trail<<Normalizer2Impl::COMP_2_TRAIL_SHIFT)|
+                       (compositeAndFwd>>16);
+            thirdUnit=compositeAndFwd;
+        }
+        // Set the high bit of the first unit if this is the last composition pair.
+        if(i==(length-1)) {
+            firstUnit|=Normalizer2Impl::COMP_1_LAST_TUPLE;
+        }
+        dataString.append((UChar)firstUnit).append((UChar)secondUnit);
+        if(thirdUnit>=0) {
+            dataString.append((UChar)thirdUnit);
+        }
+    }
+}
+
+class ExtraDataWriter : public Normalizer2DBEnumerator {
+public:
+    ExtraDataWriter(Normalizer2DataBuilder &b) :
+        Normalizer2DBEnumerator(b),
+        yesYesCompositions(1000, (UChar32)0xffff, 2),  // 0=inert, 1=Jamo L, 2=start of compositions
+        yesNoData(1000, (UChar32)0, 1) {}  // 0=Hangul, 1=start of normal data
+    virtual UBool rangeHandler(UChar32 start, UChar32 end, uint32_t value) {
+        if(value!=0) {
+            if(start!=end) {
+                fprintf(stderr,
+                        "gennorm2 error: unexpected shared data for "
+                        "multiple code points U+%04lX..U+%04lX\n",
+                        (long)start, (long)end);
+                exit(U_INTERNAL_PROGRAM_ERROR);
+            }
+            builder.writeExtraData(start, value, *this);
+        }
+        return TRUE;
+    }
+    UnicodeString maybeYesCompositions;
+    UnicodeString yesYesCompositions;
+    UnicodeString yesNoData;
+    UnicodeString noNoMappings;
+    Hashtable previousNoNoMappings;  // If constructed in runtime code, pass in UErrorCode.
+};
+
+void Normalizer2DataBuilder::writeExtraData(UChar32 c, uint32_t value, ExtraDataWriter &writer) {
+    Norm *p=norms+value;
+    if(p->combinesBack) {
+        if(p->hasMapping()) {
+            fprintf(stderr,
+                    "gennorm2 error: "
+                    "U+%04lX combines-back and decomposes, not possible in Unicode normalization\n",
+                    (long)c);
+            exit(U_INVALID_FORMAT_ERROR);
+        }
+        if(p->compositions!=NULL) {
+            p->offset=
+                (writer.maybeYesCompositions.length()<<Norm::OFFSET_SHIFT)|
+                Norm::OFFSET_MAYBE_YES;
+            writeCompositions(c, p, writer.maybeYesCompositions);
+        }
+    } else if(!p->hasMapping()) {
+        if(p->compositions!=NULL) {
+            p->offset=
+                (writer.yesYesCompositions.length()<<Norm::OFFSET_SHIFT)|
+                Norm::OFFSET_YES_YES;
+            writeCompositions(c, p, writer.yesYesCompositions);
+        }
+    } else if(p->mappingType==Norm::ROUND_TRIP) {
+        p->offset=
+            (writer.yesNoData.length()<<Norm::OFFSET_SHIFT)|
+            Norm::OFFSET_YES_NO;
+        writeMapping(c, p, writer.yesNoData);
+        if(p->compositions!=NULL) {
+            writeCompositions(c, p, writer.yesNoData);
+        }
+    } else /* one-way */ {
+        if(p->compositions!=NULL) {
+            fprintf(stderr,
+                    "gennorm2 error: "
+                    "U+%04lX combines-forward and has a one-way mapping, "
+                    "not possible in Unicode normalization\n",
+                    (long)c);
+            exit(U_INVALID_FORMAT_ERROR);
+        }
+        if(p->cc==0 && optimization!=OPTIMIZE_FAST) {
+            // Try a compact, algorithmic encoding.
+            // Only for ccc=0, because we can't store additional information.
+            if(p->mappingCP>=0) {
+                int32_t delta=p->mappingCP-c;
+                if(-Normalizer2Impl::MAX_DELTA<=delta && delta<=Normalizer2Impl::MAX_DELTA) {
+                    p->offset=(delta<<Norm::OFFSET_SHIFT)|Norm::OFFSET_DELTA;
+                }
+            }
+        }
+        if(p->offset==0) {
+            int32_t oldNoNoLength=writer.noNoMappings.length();
+            writeMapping(c, p, writer.noNoMappings);
+            UnicodeString newMapping=writer.noNoMappings.tempSubString(oldNoNoLength);
+            int32_t previousOffset=writer.previousNoNoMappings.geti(newMapping);
+            if(previousOffset!=0) {
+                // Duplicate, remove the new units and point to the old ones.
+                writer.noNoMappings.truncate(oldNoNoLength);
+                p->offset=
+                    ((previousOffset-1)<<Norm::OFFSET_SHIFT)|
+                    Norm::OFFSET_NO_NO;
+            } else {
+                // Enter this new mapping into the hashtable, avoiding value 0 which is "not found".
+                IcuToolErrorCode errorCode("gennorm2/writeExtraData()/Hashtable.puti()");
+                writer.previousNoNoMappings.puti(newMapping, oldNoNoLength+1, errorCode);
+                p->offset=
+                    (oldNoNoLength<<Norm::OFFSET_SHIFT)|
+                    Norm::OFFSET_NO_NO;
+            }
+        }
+    }
+}
+
+class Norm16Writer : public Normalizer2DBEnumerator {
+public:
+    Norm16Writer(Normalizer2DataBuilder &b) : Normalizer2DBEnumerator(b) {}
+    virtual UBool rangeHandler(UChar32 start, UChar32 end, uint32_t value) {
+        builder.writeNorm16(start, end, value);
+        return TRUE;
+    }
+};
+
+void Normalizer2DataBuilder::writeNorm16(UChar32 start, UChar32 end, uint32_t value) {
+    if(value!=0) {
+        const Norm *p=norms+value;
+        int32_t offset=p->offset>>Norm::OFFSET_SHIFT;
+        int32_t norm16=0;
+        UBool isDecompNo=FALSE;
+        UBool isCompNoMaybe=FALSE;
+        switch(p->offset&Norm::OFFSET_MASK) {
+        case Norm::OFFSET_NONE:
+            // No mapping, no compositions list.
+            if(p->combinesBack) {
+                norm16=Normalizer2Impl::MIN_NORMAL_MAYBE_YES+p->cc;
+                isDecompNo=(UBool)(p->cc!=0);
+                isCompNoMaybe=TRUE;
+            } else if(p->cc!=0) {
+                norm16=Normalizer2Impl::MIN_YES_YES_WITH_CC-1+p->cc;
+                isDecompNo=isCompNoMaybe=TRUE;
+            }
+            break;
+        case Norm::OFFSET_MAYBE_YES:
+            norm16=indexes[Normalizer2Impl::IX_MIN_MAYBE_YES]+offset;
+            isCompNoMaybe=TRUE;
+            break;
+        case Norm::OFFSET_YES_YES:
+            norm16=offset;
+            break;
+        case Norm::OFFSET_YES_NO:
+            norm16=indexes[Normalizer2Impl::IX_MIN_YES_NO]+offset;
+            isDecompNo=TRUE;
+            break;
+        case Norm::OFFSET_NO_NO:
+            norm16=indexes[Normalizer2Impl::IX_MIN_NO_NO]+offset;
+            isDecompNo=isCompNoMaybe=TRUE;
+            break;
+        case Norm::OFFSET_DELTA:
+            norm16=getCenterNoNoDelta()+offset;
+            isDecompNo=isCompNoMaybe=TRUE;
+            break;
+        default:  // Should not occur.
+            exit(U_INTERNAL_PROGRAM_ERROR);
+        }
+        IcuToolErrorCode errorCode("gennorm2/writeNorm16()");
+        utrie2_setRange32(norm16Trie, start, end, (uint32_t)norm16, TRUE, errorCode);
+        if(isDecompNo && start<indexes[Normalizer2Impl::IX_MIN_DECOMP_NO_CP]) {
+            indexes[Normalizer2Impl::IX_MIN_DECOMP_NO_CP]=start;
+        }
+        if(isCompNoMaybe && start<indexes[Normalizer2Impl::IX_MIN_COMP_NO_MAYBE_CP]) {
+            indexes[Normalizer2Impl::IX_MIN_COMP_NO_MAYBE_CP]=start;
+        }
+    }
+}
+
+void Normalizer2DataBuilder::setHangulData() {
+    HangulIterator hi;
+    const HangulIterator::Range *range;
+    // Check that none of the Hangul/Jamo code points have data.
+    while((range=hi.nextRange())!=NULL) {
+        for(UChar32 c=range->start; c<range->limit; ++c) {
+            if(utrie2_get32(norm16Trie, c)!=0) {
+                fprintf(stderr,
+                        "gennorm2 error: "
+                        "illegal mapping/composition/ccc data for Hangul or Jamo U+%04lX\n",
+                        (long)c);
+                exit(U_INVALID_FORMAT_ERROR);
+            }
+        }
+    }
+    // Set data for algorithmic runtime handling.
+    IcuToolErrorCode errorCode("gennorm2/setHangulData()");
+    hi.reset();
+    while((range=hi.nextRange())!=NULL) {
+        uint16_t norm16=range->norm16;
+        if(norm16==0) {
+            norm16=(uint16_t)indexes[Normalizer2Impl::IX_MIN_YES_NO];  // Hangul LV/LVT encoded as minYesNo
+            if(range->start<indexes[Normalizer2Impl::IX_MIN_DECOMP_NO_CP]) {
+                indexes[Normalizer2Impl::IX_MIN_DECOMP_NO_CP]=range->start;
+            }
+        } else {
+            if(range->start<indexes[Normalizer2Impl::IX_MIN_COMP_NO_MAYBE_CP]) {  // Jamo V/T are maybeYes
+                indexes[Normalizer2Impl::IX_MIN_COMP_NO_MAYBE_CP]=range->start;
+            }
+        }
+        utrie2_setRange32(norm16Trie, range->start, range->limit-1, norm16, TRUE, errorCode);
+        errorCode.assertSuccess();
+    }
+}
+
+U_CDECL_BEGIN
+
+static UBool U_CALLCONV
+enumRangeMaxValue(const void *context, UChar32 /*start*/, UChar32 /*end*/, uint32_t value) {
+    uint32_t *pMaxValue=(uint32_t *)context;
+    if(value>*pMaxValue) {
+        *pMaxValue=value;
+    }
+    return TRUE;
+}
+
+U_CDECL_END
+
+void Normalizer2DataBuilder::processData() {
+    IcuToolErrorCode errorCode("gennorm2/processData()");
+    norm16Trie=utrie2_open(0, 0, errorCode);
+    errorCode.assertSuccess();
+
+    utrie2_enum(normTrie, NULL, enumRangeHandler, CompositionBuilder(*this).ptr());
+
+    Decomposer decomposer(*this);
+    do {
+        decomposer.didDecompose=FALSE;
+        utrie2_enum(normTrie, NULL, enumRangeHandler, &decomposer);
+    } while(decomposer.didDecompose);
+
+    BuilderReorderingBuffer buffer;
+    int32_t normsLength=utm_countItems(normMem);
+    for(int32_t i=1; i<normsLength; ++i) {
+        if(norms[i].hasMapping()) {
+            buffer.reset();
+            reorder(norms+i, buffer);
+            norms[i].hasNoCompBoundaryAfter=hasNoCompBoundaryAfter(buffer);
+        }
+    }
+
+    indexes[Normalizer2Impl::IX_MIN_DECOMP_NO_CP]=0x110000;
+    indexes[Normalizer2Impl::IX_MIN_COMP_NO_MAYBE_CP]=0x110000;
+
+    ExtraDataWriter extraDataWriter(*this);
+    utrie2_enum(normTrie, NULL, enumRangeHandler, &extraDataWriter);
+
+    extraData=extraDataWriter.maybeYesCompositions;
+    extraData.append(extraDataWriter.yesYesCompositions).
+              append(extraDataWriter.yesNoData).
+              append(extraDataWriter.noNoMappings);
+    // Pad to even length for 4-byte alignment of following data.
+    if(extraData.length()&1) {
+        extraData.append((UChar)0);
+    }
+
+    indexes[Normalizer2Impl::IX_MIN_YES_NO]=
+        extraDataWriter.yesYesCompositions.length();
+    indexes[Normalizer2Impl::IX_MIN_NO_NO]=
+        indexes[Normalizer2Impl::IX_MIN_YES_NO]+
+        extraDataWriter.yesNoData.length();
+    indexes[Normalizer2Impl::IX_LIMIT_NO_NO]=
+        indexes[Normalizer2Impl::IX_MIN_NO_NO]+
+        extraDataWriter.noNoMappings.length();
+    indexes[Normalizer2Impl::IX_MIN_MAYBE_YES]=
+        Normalizer2Impl::MIN_NORMAL_MAYBE_YES-
+        extraDataWriter.maybeYesCompositions.length();
+
+    int32_t minNoNoDelta=getCenterNoNoDelta()-Normalizer2Impl::MAX_DELTA;
+    if(indexes[Normalizer2Impl::IX_LIMIT_NO_NO]>minNoNoDelta) {
+        fprintf(stderr,
+                "gennorm2 error: "
+                "data structure overflow, too much mapping composition data\n");
+        exit(U_BUFFER_OVERFLOW_ERROR);
+    }
+
+    utrie2_enum(normTrie, NULL, enumRangeHandler, Norm16Writer(*this).ptr());
+
+    setHangulData();
+
+    // Look for the "worst" norm16 value of any supplementary code point
+    // corresponding to a lead surrogate, and set it as that surrogate's value.
+    // Enables quick check inner loops to look at only code units.
+    //
+    // We could be more sophisticated:
+    // We could collect a bit set for whether there are values in the different
+    // norm16 ranges (yesNo, maybeYes, yesYesWithCC etc.)
+    // and select the best value that only breaks the composition and/or decomposition
+    // inner loops if necessary.
+    // However, that seems like overkill for an optimization for supplementary characters.
+    for(UChar lead=0xd800; lead<0xdc00; ++lead) {
+        uint32_t maxValue=utrie2_get32(norm16Trie, lead);
+        utrie2_enumForLeadSurrogate(norm16Trie, lead, NULL, enumRangeMaxValue, &maxValue);
+        if( maxValue>=(uint32_t)indexes[Normalizer2Impl::IX_LIMIT_NO_NO] &&
+            maxValue>(uint32_t)indexes[Normalizer2Impl::IX_MIN_NO_NO]
+        ) {
+            // Set noNo ("worst" value) if it got into "less-bad" maybeYes or ccc!=0.
+            // Otherwise it might end up at something like JAMO_VT which stays in
+            // the inner decomposition quick check loop.
+            maxValue=(uint32_t)indexes[Normalizer2Impl::IX_LIMIT_NO_NO]-1;
+        }
+        utrie2_set32ForLeadSurrogateCodeUnit(norm16Trie, lead, maxValue, errorCode);
+    }
+
+    // Adjust supplementary minimum code points to break quick check loops at their lead surrogates.
+    // For an empty data file, minCP=0x110000 turns into 0xdc00 (first trail surrogate)
+    // which is harmless.
+    // As a result, the minimum code points are always BMP code points.
+    int32_t minCP=indexes[Normalizer2Impl::IX_MIN_DECOMP_NO_CP];
+    if(minCP>=0x10000) {
+        indexes[Normalizer2Impl::IX_MIN_DECOMP_NO_CP]=U16_LEAD(minCP);
+    }
+    minCP=indexes[Normalizer2Impl::IX_MIN_COMP_NO_MAYBE_CP];
+    if(minCP>=0x10000) {
+        indexes[Normalizer2Impl::IX_MIN_COMP_NO_MAYBE_CP]=U16_LEAD(minCP);
+    }
+}
+
+void Normalizer2DataBuilder::writeBinaryFile(const char *filename) {
+    processData();
+
+    IcuToolErrorCode errorCode("gennorm2/writeBinaryFile()");
+    utrie2_freeze(norm16Trie, UTRIE2_16_VALUE_BITS, errorCode);
+    int32_t norm16TrieLength=utrie2_serialize(norm16Trie, NULL, 0, errorCode);
+    if(errorCode.get()!=U_BUFFER_OVERFLOW_ERROR) {
+        fprintf(stderr, "gennorm2 error: unable to freeze/serialize the normalization trie - %s\n",
+                errorCode.errorName());
+        exit(errorCode.reset());
+    }
+    errorCode.reset();
+    LocalArray<uint8_t> norm16TrieBytes(new uint8_t[norm16TrieLength]);
+    utrie2_serialize(norm16Trie, norm16TrieBytes.getAlias(), norm16TrieLength, errorCode);
+    errorCode.assertSuccess();
+
+    int32_t offset=(int32_t)sizeof(indexes);
+    indexes[Normalizer2Impl::IX_NORM_TRIE_OFFSET]=offset;
+    offset+=norm16TrieLength;
+    indexes[Normalizer2Impl::IX_EXTRA_DATA_OFFSET]=offset;
+    int32_t totalSize=offset+=extraData.length()*2;
+    for(int32_t i=Normalizer2Impl::IX_RESERVED2_OFFSET; i<=Normalizer2Impl::IX_TOTAL_SIZE; ++i) {
+        indexes[i]=totalSize;
+    }
+
+    if(beVerbose) {
+        printf("size of normalization trie:         %5ld bytes\n", (long)norm16TrieLength);
+        printf("size of 16-bit extra data:          %5ld uint16_t\n", (long)extraData.length());
+        printf("size of binary data file contents:  %5ld bytes\n", (long)totalSize);
+        printf("minDecompNoCodePoint:              U+%04lX\n", (long)indexes[Normalizer2Impl::IX_MIN_DECOMP_NO_CP]);
+        printf("minCompNoMaybeCodePoint:           U+%04lX\n", (long)indexes[Normalizer2Impl::IX_MIN_COMP_NO_MAYBE_CP]);
+        printf("minYesNo:                          0x%04x\n", (int)indexes[Normalizer2Impl::IX_MIN_YES_NO]);
+        printf("minNoNo:                           0x%04x\n", (int)indexes[Normalizer2Impl::IX_MIN_NO_NO]);
+        printf("limitNoNo:                         0x%04x\n", (int)indexes[Normalizer2Impl::IX_LIMIT_NO_NO]);
+        printf("minMaybeYes:                       0x%04x\n", (int)indexes[Normalizer2Impl::IX_MIN_MAYBE_YES]);
+    }
+
+    memcpy(dataInfo.dataVersion, unicodeVersion, 4);
+    UNewDataMemory *pData=
+        udata_create(NULL, NULL, filename, &dataInfo,
+                     haveCopyright ? U_COPYRIGHT_STRING : NULL, errorCode);
+    if(errorCode.isFailure()) {
+        fprintf(stderr, "gennorm2 error: unable to create the output file %s - %s\n",
+                filename, errorCode.errorName());
+        exit(errorCode.reset());
+    }
+    udata_writeBlock(pData, indexes, sizeof(indexes));
+    udata_writeBlock(pData, norm16TrieBytes.getAlias(), norm16TrieLength);
+    udata_writeUString(pData, extraData.getBuffer(), extraData.length());
+
+    int32_t writtenSize=udata_finish(pData, errorCode);
+    if(errorCode.isFailure()) {
+        fprintf(stderr, "gennorm2: error %s writing the output file\n", errorCode.errorName());
+        exit(errorCode.reset());
+    }
+    if(writtenSize!=totalSize) {
+        fprintf(stderr, "gennorm2 error: written size %ld != calculated size %ld\n",
+            (long)writtenSize, (long)totalSize);
+        exit(U_INTERNAL_PROGRAM_ERROR);
+    }
+}
+
+U_NAMESPACE_END
+
+#endif /* #if !UCONFIG_NO_NORMALIZATION */
+
+/*
+ * Hey, Emacs, please set the following:
+ *
+ * Local Variables:
+ * indent-tabs-mode: nil
+ * End:
+ */