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-rw-r--r--xpcom/string/nsTextFormatter.cpp895
1 files changed, 895 insertions, 0 deletions
diff --git a/xpcom/string/nsTextFormatter.cpp b/xpcom/string/nsTextFormatter.cpp
new file mode 100644
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+++ b/xpcom/string/nsTextFormatter.cpp
@@ -0,0 +1,895 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * Portable safe sprintf code.
+ *
+ * Code based on mozilla/nsprpub/src/io/prprf.c rev 3.7
+ *
+ * Contributor(s):
+ * Kipp E.B. Hickman <kipp@netscape.com> (original author)
+ * Frank Yung-Fong Tang <ftang@netscape.com>
+ * Daniele Nicolodi <daniele@grinta.net>
+ */
+
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+#include "prdtoa.h"
+#include "mozilla/Logging.h"
+#include "mozilla/Sprintf.h"
+#include "nsCRTGlue.h"
+#include "nsTextFormatter.h"
+
+struct nsTextFormatter::SprintfStateStr {
+ int (*stuff)(SprintfStateStr* aState, const char16_t* aStr, uint32_t aLen);
+
+ char16_t* base;
+ char16_t* cur;
+ uint32_t maxlen;
+
+ void* stuffclosure;
+};
+
+#define _LEFT 0x1
+#define _SIGNED 0x2
+#define _SPACED 0x4
+#define _ZEROS 0x8
+#define _NEG 0x10
+#define _UNSIGNED 0x20
+
+#define ELEMENTS_OF(array_) (sizeof(array_) / sizeof(array_[0]))
+
+/*
+** Fill into the buffer using the data in src
+*/
+int nsTextFormatter::fill2(SprintfStateStr* aState, const char16_t* aSrc,
+ int aSrcLen, int aWidth, int aFlags) {
+ char16_t space = ' ';
+ int rv;
+
+ aWidth -= aSrcLen;
+ /* Right adjusting */
+ if ((aWidth > 0) && ((aFlags & _LEFT) == 0)) {
+ if (aFlags & _ZEROS) {
+ space = '0';
+ }
+ while (--aWidth >= 0) {
+ rv = (*aState->stuff)(aState, &space, 1);
+ if (rv < 0) {
+ return rv;
+ }
+ }
+ }
+
+ /* Copy out the source data */
+ rv = (*aState->stuff)(aState, aSrc, aSrcLen);
+ if (rv < 0) {
+ return rv;
+ }
+
+ /* Left adjusting */
+ if ((aWidth > 0) && ((aFlags & _LEFT) != 0)) {
+ while (--aWidth >= 0) {
+ rv = (*aState->stuff)(aState, &space, 1);
+ if (rv < 0) {
+ return rv;
+ }
+ }
+ }
+ return 0;
+}
+
+/*
+** Fill a number. The order is: optional-sign zero-filling conversion-digits
+*/
+int nsTextFormatter::fill_n(nsTextFormatter::SprintfStateStr* aState,
+ const char16_t* aSrc, int aSrcLen, int aWidth,
+ int aPrec, int aFlags) {
+ int zerowidth = 0;
+ int precwidth = 0;
+ int signwidth = 0;
+ int leftspaces = 0;
+ int rightspaces = 0;
+ int cvtwidth;
+ int rv;
+ char16_t sign;
+ char16_t space = ' ';
+ char16_t zero = '0';
+
+ if ((aFlags & _UNSIGNED) == 0) {
+ if (aFlags & _NEG) {
+ sign = '-';
+ signwidth = 1;
+ } else if (aFlags & _SIGNED) {
+ sign = '+';
+ signwidth = 1;
+ } else if (aFlags & _SPACED) {
+ sign = ' ';
+ signwidth = 1;
+ }
+ }
+ cvtwidth = signwidth + aSrcLen;
+
+ if (aPrec > 0) {
+ if (aPrec > aSrcLen) {
+ /* Need zero filling */
+ precwidth = aPrec - aSrcLen;
+ cvtwidth += precwidth;
+ }
+ }
+
+ if ((aFlags & _ZEROS) && (aPrec < 0)) {
+ if (aWidth > cvtwidth) {
+ /* Zero filling */
+ zerowidth = aWidth - cvtwidth;
+ cvtwidth += zerowidth;
+ }
+ }
+
+ if (aFlags & _LEFT) {
+ if (aWidth > cvtwidth) {
+ /* Space filling on the right (i.e. left adjusting) */
+ rightspaces = aWidth - cvtwidth;
+ }
+ } else {
+ if (aWidth > cvtwidth) {
+ /* Space filling on the left (i.e. right adjusting) */
+ leftspaces = aWidth - cvtwidth;
+ }
+ }
+ while (--leftspaces >= 0) {
+ rv = (*aState->stuff)(aState, &space, 1);
+ if (rv < 0) {
+ return rv;
+ }
+ }
+ if (signwidth) {
+ rv = (*aState->stuff)(aState, &sign, 1);
+ if (rv < 0) {
+ return rv;
+ }
+ }
+ while (--precwidth >= 0) {
+ rv = (*aState->stuff)(aState, &space, 1);
+ if (rv < 0) {
+ return rv;
+ }
+ }
+ while (--zerowidth >= 0) {
+ rv = (*aState->stuff)(aState, &zero, 1);
+ if (rv < 0) {
+ return rv;
+ }
+ }
+ rv = (*aState->stuff)(aState, aSrc, aSrcLen);
+ if (rv < 0) {
+ return rv;
+ }
+ while (--rightspaces >= 0) {
+ rv = (*aState->stuff)(aState, &space, 1);
+ if (rv < 0) {
+ return rv;
+ }
+ }
+ return 0;
+}
+
+/*
+** Convert a 64-bit integer into its printable form
+*/
+int nsTextFormatter::cvt_ll(SprintfStateStr* aState, uint64_t aNum, int aWidth,
+ int aPrec, int aRadix, int aFlags,
+ const char16_t* aHexStr) {
+ char16_t cvtbuf[100];
+ char16_t* cvt;
+ int digits;
+
+ /* according to the man page this needs to happen */
+ if (aPrec == 0 && aNum == 0) {
+ return 0;
+ }
+
+ /*
+ ** Converting decimal is a little tricky. In the unsigned case we
+ ** need to stop when we hit 10 digits. In the signed case, we can
+ ** stop when the number is zero.
+ */
+ cvt = &cvtbuf[0] + ELEMENTS_OF(cvtbuf);
+ digits = 0;
+ while (aNum != 0) {
+ uint64_t quot = aNum / aRadix;
+ uint64_t rem = aNum % aRadix;
+ *--cvt = aHexStr[rem & 0xf];
+ digits++;
+ aNum = quot;
+ }
+ if (digits == 0) {
+ *--cvt = '0';
+ digits++;
+ }
+
+ /*
+ ** Now that we have the number converted without its sign, deal with
+ ** the sign and zero padding.
+ */
+ return fill_n(aState, cvt, digits, aWidth, aPrec, aFlags);
+}
+
+/*
+** Convert a double precision floating point number into its printable
+** form.
+*/
+int nsTextFormatter::cvt_f(SprintfStateStr* aState, double aDouble, int aWidth,
+ int aPrec, const char16_t aType, int aFlags) {
+ int mode = 2;
+ int decpt;
+ int sign;
+ char buf[256];
+ char* bufp = buf;
+ int bufsz = 256;
+ char num[256];
+ char* nump;
+ char* endnum;
+ int numdigits = 0;
+ char exp = 'e';
+
+ if (aPrec == -1) {
+ aPrec = 6;
+ } else if (aPrec > 50) {
+ // limit precision to avoid PR_dtoa bug 108335
+ // and to prevent buffers overflows
+ aPrec = 50;
+ }
+
+ switch (aType) {
+ case 'f':
+ numdigits = aPrec;
+ mode = 3;
+ break;
+ case 'E':
+ exp = 'E';
+ [[fallthrough]];
+ case 'e':
+ numdigits = aPrec + 1;
+ mode = 2;
+ break;
+ case 'G':
+ exp = 'E';
+ [[fallthrough]];
+ case 'g':
+ if (aPrec == 0) {
+ aPrec = 1;
+ }
+ numdigits = aPrec;
+ mode = 2;
+ break;
+ default:
+ NS_ERROR("invalid aType passed to cvt_f");
+ }
+
+ if (PR_dtoa(aDouble, mode, numdigits, &decpt, &sign, &endnum, num, bufsz) ==
+ PR_FAILURE) {
+ buf[0] = '\0';
+ return -1;
+ }
+ numdigits = endnum - num;
+ nump = num;
+
+ if (sign) {
+ *bufp++ = '-';
+ } else if (aFlags & _SIGNED) {
+ *bufp++ = '+';
+ }
+
+ if (decpt == 9999) {
+ while ((*bufp++ = *nump++)) {
+ }
+ } else {
+ switch (aType) {
+ case 'E':
+ case 'e':
+
+ *bufp++ = *nump++;
+ if (aPrec > 0) {
+ *bufp++ = '.';
+ while (*nump) {
+ *bufp++ = *nump++;
+ aPrec--;
+ }
+ while (aPrec-- > 0) {
+ *bufp++ = '0';
+ }
+ }
+ *bufp++ = exp;
+
+ ::snprintf(bufp, bufsz - (bufp - buf), "%+03d", decpt - 1);
+ break;
+
+ case 'f':
+
+ if (decpt < 1) {
+ *bufp++ = '0';
+ if (aPrec > 0) {
+ *bufp++ = '.';
+ while (decpt++ && aPrec-- > 0) {
+ *bufp++ = '0';
+ }
+ while (*nump && aPrec-- > 0) {
+ *bufp++ = *nump++;
+ }
+ while (aPrec-- > 0) {
+ *bufp++ = '0';
+ }
+ }
+ } else {
+ while (*nump && decpt-- > 0) {
+ *bufp++ = *nump++;
+ }
+ while (decpt-- > 0) {
+ *bufp++ = '0';
+ }
+ if (aPrec > 0) {
+ *bufp++ = '.';
+ while (*nump && aPrec-- > 0) {
+ *bufp++ = *nump++;
+ }
+ while (aPrec-- > 0) {
+ *bufp++ = '0';
+ }
+ }
+ }
+ *bufp = '\0';
+ break;
+
+ case 'G':
+ case 'g':
+
+ if ((decpt < -3) || ((decpt - 1) >= aPrec)) {
+ *bufp++ = *nump++;
+ numdigits--;
+ if (numdigits > 0) {
+ *bufp++ = '.';
+ while (*nump) {
+ *bufp++ = *nump++;
+ }
+ }
+ *bufp++ = exp;
+ ::snprintf(bufp, bufsz - (bufp - buf), "%+03d", decpt - 1);
+ } else {
+ if (decpt < 1) {
+ *bufp++ = '0';
+ if (aPrec > 0) {
+ *bufp++ = '.';
+ while (decpt++) {
+ *bufp++ = '0';
+ }
+ while (*nump) {
+ *bufp++ = *nump++;
+ }
+ }
+ } else {
+ while (*nump && decpt-- > 0) {
+ *bufp++ = *nump++;
+ numdigits--;
+ }
+ while (decpt-- > 0) {
+ *bufp++ = '0';
+ }
+ if (numdigits > 0) {
+ *bufp++ = '.';
+ while (*nump) {
+ *bufp++ = *nump++;
+ }
+ }
+ }
+ *bufp = '\0';
+ }
+ }
+ }
+
+ char16_t rbuf[256];
+ char16_t* rbufp = rbuf;
+ bufp = buf;
+ // cast to char16_t
+ while ((*rbufp++ = *bufp++)) {
+ }
+ *rbufp = '\0';
+
+ return fill2(aState, rbuf, NS_strlen(rbuf), aWidth, aFlags);
+}
+
+/*
+** Convert a string into its printable form. |aWidth| is the output
+** width. |aPrec| is the maximum number of characters of |aStr| to output,
+** where -1 means until NUL.
+*/
+int nsTextFormatter::cvt_S(SprintfStateStr* aState, const char16_t* aStr,
+ int aWidth, int aPrec, int aFlags) {
+ int slen;
+
+ if (aPrec == 0) {
+ return 0;
+ }
+
+ /* Limit string length by precision value */
+ slen = aStr ? NS_strlen(aStr) : 6;
+ if (aPrec > 0) {
+ if (aPrec < slen) {
+ slen = aPrec;
+ }
+ }
+
+ /* and away we go */
+ return fill2(aState, aStr ? aStr : u"(null)", slen, aWidth, aFlags);
+}
+
+/*
+** Convert a string into its printable form. |aWidth| is the output
+** width. |aPrec| is the maximum number of characters of |aStr| to output,
+** where -1 means until NUL.
+*/
+int nsTextFormatter::cvt_s(nsTextFormatter::SprintfStateStr* aState,
+ const char* aStr, int aWidth, int aPrec,
+ int aFlags) {
+ // Be sure to handle null the same way as %S.
+ if (aStr == nullptr) {
+ return cvt_S(aState, nullptr, aWidth, aPrec, aFlags);
+ }
+ NS_ConvertUTF8toUTF16 utf16Val(aStr);
+ return cvt_S(aState, utf16Val.get(), aWidth, aPrec, aFlags);
+}
+
+/*
+** The workhorse sprintf code.
+*/
+int nsTextFormatter::dosprintf(SprintfStateStr* aState, const char16_t* aFmt,
+ mozilla::Span<BoxedValue> aValues) {
+ static const char16_t space = ' ';
+ static const char16_t hex[] = u"0123456789abcdef";
+ static const char16_t HEX[] = u"0123456789ABCDEF";
+ static const BoxedValue emptyString(u"");
+
+ char16_t c;
+ int flags, width, prec, radix;
+
+ const char16_t* hexp;
+
+ // Next argument for non-numbered arguments.
+ size_t nextNaturalArg = 0;
+ // True if we ever saw a numbered argument.
+ bool sawNumberedArg = false;
+
+ while ((c = *aFmt++) != 0) {
+ int rv;
+
+ if (c != '%') {
+ rv = (*aState->stuff)(aState, aFmt - 1, 1);
+ if (rv < 0) {
+ return rv;
+ }
+ continue;
+ }
+
+ // Save the location of the "%" in case we decide it isn't a
+ // format and want to just emit the text from the format string.
+ const char16_t* percentPointer = aFmt - 1;
+
+ /*
+ ** Gobble up the % format string. Hopefully we have handled all
+ ** of the strange cases!
+ */
+ flags = 0;
+ c = *aFmt++;
+ if (c == '%') {
+ /* quoting a % with %% */
+ rv = (*aState->stuff)(aState, aFmt - 1, 1);
+ if (rv < 0) {
+ return rv;
+ }
+ continue;
+ }
+
+ // Check for a numbered argument.
+ bool sawWidth = false;
+ const BoxedValue* thisArg = nullptr;
+ if (c >= '0' && c <= '9') {
+ size_t argNumber = 0;
+ while (c && c >= '0' && c <= '9') {
+ argNumber = (argNumber * 10) + (c - '0');
+ c = *aFmt++;
+ }
+
+ if (c == '$') {
+ // Mixing numbered arguments and implicit arguments is
+ // disallowed.
+ if (nextNaturalArg > 0) {
+ return -1;
+ }
+
+ c = *aFmt++;
+
+ // Numbered arguments start at 1.
+ --argNumber;
+ if (argNumber >= aValues.Length()) {
+ // A correctness issue but not a safety issue.
+ MOZ_ASSERT(false);
+ thisArg = &emptyString;
+ } else {
+ thisArg = &aValues[argNumber];
+ }
+ sawNumberedArg = true;
+ } else {
+ width = argNumber;
+ sawWidth = true;
+ }
+ }
+
+ if (!sawWidth) {
+ /*
+ * Examine optional flags. Note that we do not implement the
+ * '#' flag of sprintf(). The ANSI C spec. of the '#' flag is
+ * somewhat ambiguous and not ideal, which is perhaps why
+ * the various sprintf() implementations are inconsistent
+ * on this feature.
+ */
+ while ((c == '-') || (c == '+') || (c == ' ') || (c == '0')) {
+ if (c == '-') {
+ flags |= _LEFT;
+ }
+ if (c == '+') {
+ flags |= _SIGNED;
+ }
+ if (c == ' ') {
+ flags |= _SPACED;
+ }
+ if (c == '0') {
+ flags |= _ZEROS;
+ }
+ c = *aFmt++;
+ }
+ if (flags & _SIGNED) {
+ flags &= ~_SPACED;
+ }
+ if (flags & _LEFT) {
+ flags &= ~_ZEROS;
+ }
+
+ /* width */
+ if (c == '*') {
+ // Not supported with numbered arguments.
+ if (sawNumberedArg) {
+ return -1;
+ }
+
+ if (nextNaturalArg >= aValues.Length() ||
+ !aValues[nextNaturalArg].IntCompatible()) {
+ // A correctness issue but not a safety issue.
+ MOZ_ASSERT(false);
+ width = 0;
+ } else {
+ width = aValues[nextNaturalArg++].mValue.mInt;
+ }
+ c = *aFmt++;
+ } else {
+ width = 0;
+ while ((c >= '0') && (c <= '9')) {
+ width = (width * 10) + (c - '0');
+ c = *aFmt++;
+ }
+ }
+ }
+
+ /* precision */
+ prec = -1;
+ if (c == '.') {
+ c = *aFmt++;
+ if (c == '*') {
+ // Not supported with numbered arguments.
+ if (sawNumberedArg) {
+ return -1;
+ }
+
+ if (nextNaturalArg >= aValues.Length() ||
+ !aValues[nextNaturalArg].IntCompatible()) {
+ // A correctness issue but not a safety issue.
+ MOZ_ASSERT(false);
+ } else {
+ prec = aValues[nextNaturalArg++].mValue.mInt;
+ }
+ c = *aFmt++;
+ } else {
+ prec = 0;
+ while ((c >= '0') && (c <= '9')) {
+ prec = (prec * 10) + (c - '0');
+ c = *aFmt++;
+ }
+ }
+ }
+
+ // If the argument isn't known yet, find it now. This is done
+ // after the width and precision code, in case '*' was used.
+ if (thisArg == nullptr) {
+ // Mixing numbered arguments and implicit arguments is
+ // disallowed.
+ if (sawNumberedArg) {
+ return -1;
+ }
+
+ if (nextNaturalArg >= aValues.Length()) {
+ // A correctness issue but not a safety issue.
+ MOZ_ASSERT(false);
+ thisArg = &emptyString;
+ } else {
+ thisArg = &aValues[nextNaturalArg++];
+ }
+ }
+
+ /* Size. Defaults to 32 bits. */
+ uint64_t mask = UINT32_MAX;
+ if (c == 'h') {
+ c = *aFmt++;
+ mask = UINT16_MAX;
+ } else if (c == 'L') {
+ c = *aFmt++;
+ mask = UINT64_MAX;
+ } else if (c == 'l') {
+ c = *aFmt++;
+ if (c == 'l') {
+ c = *aFmt++;
+ mask = UINT64_MAX;
+ } else {
+ mask = UINT32_MAX;
+ }
+ }
+
+ /* format */
+ hexp = hex;
+ radix = 10;
+ // Several `MOZ_ASSERT`s below check for argument compatibility
+ // with the format specifier. These are only debug assertions,
+ // not release assertions, and exist to catch problems in C++
+ // callers of `nsTextFormatter`, as we do not have compile-time
+ // checking of format strings. In release mode, these assertions
+ // will be no-ops, and we will fall through to printing the
+ // argument based on the known type of the argument.
+ switch (c) {
+ case 'd':
+ case 'i': /* decimal/integer */
+ MOZ_ASSERT(thisArg->IntCompatible());
+ break;
+
+ case 'o': /* octal */
+ MOZ_ASSERT(thisArg->IntCompatible());
+ radix = 8;
+ flags |= _UNSIGNED;
+ break;
+
+ case 'u': /* unsigned decimal */
+ MOZ_ASSERT(thisArg->IntCompatible());
+ radix = 10;
+ flags |= _UNSIGNED;
+ break;
+
+ case 'x': /* unsigned hex */
+ MOZ_ASSERT(thisArg->IntCompatible());
+ radix = 16;
+ flags |= _UNSIGNED;
+ break;
+
+ case 'X': /* unsigned HEX */
+ MOZ_ASSERT(thisArg->IntCompatible());
+ radix = 16;
+ hexp = HEX;
+ flags |= _UNSIGNED;
+ break;
+
+ case 'e':
+ case 'E':
+ case 'f':
+ case 'g':
+ case 'G':
+ MOZ_ASSERT(thisArg->mKind == DOUBLE);
+ // Type-based printing below.
+ break;
+
+ case 'S':
+ case 's':
+ MOZ_ASSERT(thisArg->mKind == STRING || thisArg->mKind == STRING16);
+ // Type-based printing below.
+ break;
+
+ case 'c': {
+ if (!thisArg->IntCompatible()) {
+ MOZ_ASSERT(false);
+ // Type-based printing below.
+ break;
+ }
+
+ if ((flags & _LEFT) == 0) {
+ while (width-- > 1) {
+ rv = (*aState->stuff)(aState, &space, 1);
+ if (rv < 0) {
+ return rv;
+ }
+ }
+ }
+ char16_t ch = thisArg->mValue.mInt;
+ rv = (*aState->stuff)(aState, &ch, 1);
+ if (rv < 0) {
+ return rv;
+ }
+ if (flags & _LEFT) {
+ while (width-- > 1) {
+ rv = (*aState->stuff)(aState, &space, 1);
+ if (rv < 0) {
+ return rv;
+ }
+ }
+ }
+ }
+ continue;
+
+ case 'p':
+ if (!thisArg->PointerCompatible()) {
+ MOZ_ASSERT(false);
+ break;
+ }
+ static_assert(sizeof(uint64_t) >= sizeof(void*),
+ "pointers are larger than 64 bits");
+ rv = cvt_ll(aState, uintptr_t(thisArg->mValue.mPtr), width, prec, 16,
+ flags | _UNSIGNED, hexp);
+ if (rv < 0) {
+ return rv;
+ }
+ continue;
+
+ case 'n':
+ if (thisArg->mKind != INTPOINTER) {
+ return -1;
+ }
+
+ if (thisArg->mValue.mIntPtr != nullptr) {
+ *thisArg->mValue.mIntPtr = aState->cur - aState->base;
+ }
+ continue;
+
+ default:
+ /* Not a % token after all... skip it */
+ rv = (*aState->stuff)(aState, percentPointer, aFmt - percentPointer);
+ if (rv < 0) {
+ return rv;
+ }
+ continue;
+ }
+
+ // If we get here, we want to handle the argument according to its
+ // actual type; modified by the flags as appropriate.
+ switch (thisArg->mKind) {
+ case INT:
+ case UINT: {
+ int64_t val = thisArg->mValue.mInt;
+ if ((flags & _UNSIGNED) == 0 && val < 0) {
+ val = -val;
+ flags |= _NEG;
+ }
+ rv = cvt_ll(aState, uint64_t(val) & mask, width, prec, radix, flags,
+ hexp);
+ } break;
+ case INTPOINTER:
+ case POINTER:
+ // Always treat these as unsigned hex, no matter the format.
+ static_assert(sizeof(uint64_t) >= sizeof(void*),
+ "pointers are larger than 64 bits");
+ rv = cvt_ll(aState, uintptr_t(thisArg->mValue.mPtr), width, prec, 16,
+ flags | _UNSIGNED, hexp);
+ break;
+ case DOUBLE:
+ if (c != 'f' && c != 'E' && c != 'e' && c != 'G' && c != 'g') {
+ // Pick some default.
+ c = 'g';
+ }
+ rv = cvt_f(aState, thisArg->mValue.mDouble, width, prec, c, flags);
+ break;
+ case STRING:
+ rv = cvt_s(aState, thisArg->mValue.mString, width, prec, flags);
+ break;
+ case STRING16:
+ rv = cvt_S(aState, thisArg->mValue.mString16, width, prec, flags);
+ break;
+ default:
+ // Can't happen.
+ MOZ_ASSERT(0);
+ }
+
+ if (rv < 0) {
+ return rv;
+ }
+ }
+
+ return 0;
+}
+
+/************************************************************************/
+
+int nsTextFormatter::StringStuff(nsTextFormatter::SprintfStateStr* aState,
+ const char16_t* aStr, uint32_t aLen) {
+ ptrdiff_t off = aState->cur - aState->base;
+
+ nsAString* str = static_cast<nsAString*>(aState->stuffclosure);
+ str->Append(aStr, aLen);
+
+ aState->base = str->BeginWriting();
+ aState->cur = aState->base + off;
+
+ return 0;
+}
+
+void nsTextFormatter::vssprintf(nsAString& aOut, const char16_t* aFmt,
+ mozilla::Span<BoxedValue> aValues) {
+ SprintfStateStr ss;
+ ss.stuff = StringStuff;
+ ss.base = 0;
+ ss.cur = 0;
+ ss.maxlen = 0;
+ ss.stuffclosure = &aOut;
+
+ aOut.Truncate();
+ dosprintf(&ss, aFmt, aValues);
+}
+
+/*
+** Stuff routine that discards overflow data
+*/
+int nsTextFormatter::LimitStuff(SprintfStateStr* aState, const char16_t* aStr,
+ uint32_t aLen) {
+ uint32_t limit = aState->maxlen - (aState->cur - aState->base);
+
+ if (aLen > limit) {
+ aLen = limit;
+ }
+ while (aLen) {
+ --aLen;
+ *aState->cur++ = *aStr++;
+ }
+ return 0;
+}
+
+uint32_t nsTextFormatter::vsnprintf(char16_t* aOut, uint32_t aOutLen,
+ const char16_t* aFmt,
+ mozilla::Span<BoxedValue> aValues) {
+ SprintfStateStr ss;
+
+ MOZ_ASSERT((int32_t)aOutLen > 0);
+ if ((int32_t)aOutLen <= 0) {
+ return 0;
+ }
+
+ ss.stuff = LimitStuff;
+ ss.base = aOut;
+ ss.cur = aOut;
+ ss.maxlen = aOutLen;
+ int result = dosprintf(&ss, aFmt, aValues);
+
+ if (ss.cur == ss.base) {
+ return 0;
+ }
+
+ // Append a NUL. However, be sure not to count it in the returned
+ // length.
+ if (ss.cur - ss.base >= ptrdiff_t(ss.maxlen)) {
+ --ss.cur;
+ }
+ *ss.cur = '\0';
+
+ // Check the result now, so that an unterminated string can't
+ // possibly escape.
+ if (result < 0) {
+ return -1;
+ }
+
+ return ss.cur - ss.base;
+}