summaryrefslogtreecommitdiffstats
path: root/dom/base
diff options
context:
space:
mode:
Diffstat (limited to 'dom/base')
-rw-r--r--dom/base/nsContentUtils.cpp102
1 files changed, 58 insertions, 44 deletions
diff --git a/dom/base/nsContentUtils.cpp b/dom/base/nsContentUtils.cpp
index 13a54f0214..21519d91e6 100644
--- a/dom/base/nsContentUtils.cpp
+++ b/dom/base/nsContentUtils.cpp
@@ -8951,13 +8951,19 @@ class StringBuilder {
TextFragmentWithEncode,
};
+ struct LiteralSpan {
+ const char16_t* mData;
+ uint32_t mLength;
+
+ Span<const char16_t> AsSpan() { return Span(mData, mLength); }
+ };
+
union {
nsAtom* mAtom;
- const char16_t* mLiteral;
+ LiteralSpan mLiteral;
nsString mString;
const nsTextFragment* mTextFragment;
};
- uint32_t mLength = 0;
Type mType = Type::Unknown;
};
@@ -8987,17 +8993,15 @@ class StringBuilder {
u->mAtom = aAtom;
u->mType = Unit::Type::Atom;
uint32_t len = aAtom->GetLength();
- u->mLength = len;
mLength += len;
}
template <int N>
void Append(const char16_t (&aLiteral)[N]) {
+ constexpr uint32_t len = N - 1;
Unit* u = AddUnit();
- u->mLiteral = aLiteral;
+ u->mLiteral = {aLiteral, len};
u->mType = Unit::Type::Literal;
- uint32_t len = N - 1;
- u->mLength = len;
mLength += len;
}
@@ -9006,15 +9010,14 @@ class StringBuilder {
uint32_t len = aString.Length();
new (&u->mString) nsString(std::move(aString));
u->mType = Unit::Type::String;
- u->mLength = len;
mLength += len;
}
- void AppendWithAttrEncode(nsString&& aString, uint32_t aLen) {
+ // aLen can be !isValid(), which will get propagated into mLength.
+ void AppendWithAttrEncode(nsString&& aString, CheckedInt<uint32_t> aLen) {
Unit* u = AddUnit();
new (&u->mString) nsString(std::move(aString));
u->mType = Unit::Type::StringWithEncode;
- u->mLength = aLen;
mLength += aLen;
}
@@ -9023,15 +9026,15 @@ class StringBuilder {
u->mTextFragment = aTextFragment;
u->mType = Unit::Type::TextFragment;
uint32_t len = aTextFragment->GetLength();
- u->mLength = len;
mLength += len;
}
- void AppendWithEncode(const nsTextFragment* aTextFragment, uint32_t aLen) {
+ // aLen can be !isValid(), which will get propagated into mLength.
+ void AppendWithEncode(const nsTextFragment* aTextFragment,
+ CheckedInt<uint32_t> aLen) {
Unit* u = AddUnit();
u->mTextFragment = aTextFragment;
u->mType = Unit::Type::TextFragmentWithEncode;
- u->mLength = aLen;
mLength += aLen;
}
@@ -9062,7 +9065,7 @@ class StringBuilder {
EncodeAttrString(u.mString, appender);
break;
case Unit::Type::Literal:
- appender.Append(Span(u.mLiteral, u.mLength));
+ appender.Append(u.mLiteral.AsSpan());
break;
case Unit::Type::TextFragment:
if (u.mTextFragment->Is2b()) {
@@ -9187,7 +9190,7 @@ static_assert(sizeof(StringBuilder) <= StringBuilder::TARGET_SIZE,
static void AppendEncodedCharacters(const nsTextFragment* aText,
StringBuilder& aBuilder) {
- uint32_t extraSpaceNeeded = 0;
+ uint32_t numEncodedChars = 0;
uint32_t len = aText->GetLength();
if (aText->Is2b()) {
const char16_t* data = aText->Get2b();
@@ -9195,16 +9198,10 @@ static void AppendEncodedCharacters(const nsTextFragment* aText,
const char16_t c = data[i];
switch (c) {
case '<':
- extraSpaceNeeded += ArrayLength("&lt;") - 2;
- break;
case '>':
- extraSpaceNeeded += ArrayLength("&gt;") - 2;
- break;
case '&':
- extraSpaceNeeded += ArrayLength("&amp;") - 2;
- break;
case 0x00A0:
- extraSpaceNeeded += ArrayLength("&nbsp;") - 2;
+ ++numEncodedChars;
break;
default:
break;
@@ -9216,16 +9213,10 @@ static void AppendEncodedCharacters(const nsTextFragment* aText,
const unsigned char c = data[i];
switch (c) {
case '<':
- extraSpaceNeeded += ArrayLength("&lt;") - 2;
- break;
case '>':
- extraSpaceNeeded += ArrayLength("&gt;") - 2;
- break;
case '&':
- extraSpaceNeeded += ArrayLength("&amp;") - 2;
- break;
case 0x00A0:
- extraSpaceNeeded += ArrayLength("&nbsp;") - 2;
+ ++numEncodedChars;
break;
default:
break;
@@ -9233,28 +9224,37 @@ static void AppendEncodedCharacters(const nsTextFragment* aText,
}
}
- if (extraSpaceNeeded) {
- aBuilder.AppendWithEncode(aText, len + extraSpaceNeeded);
+ if (numEncodedChars) {
+ // For simplicity, conservatively estimate the size of the string after
+ // encoding. This will result in reserving more memory than we actually
+ // need, but that should be fine unless the string has an enormous number of
+ // eg < in it. We subtract 1 for the null terminator, then 1 more for the
+ // existing character that will be replaced.
+ constexpr uint32_t maxCharExtraSpace =
+ std::max({ArrayLength("&lt;"), ArrayLength("&gt;"),
+ ArrayLength("&amp;"), ArrayLength("&nbsp;")}) -
+ 2;
+ static_assert(maxCharExtraSpace < 100, "Possible underflow");
+ CheckedInt<uint32_t> maxExtraSpace =
+ CheckedInt<uint32_t>(numEncodedChars) * maxCharExtraSpace;
+ aBuilder.AppendWithEncode(aText, maxExtraSpace + len);
} else {
aBuilder.Append(aText);
}
}
-static uint32_t ExtraSpaceNeededForAttrEncoding(const nsAString& aValue) {
+static CheckedInt<uint32_t> ExtraSpaceNeededForAttrEncoding(
+ const nsAString& aValue) {
const char16_t* c = aValue.BeginReading();
const char16_t* end = aValue.EndReading();
- uint32_t extraSpaceNeeded = 0;
+ uint32_t numEncodedChars = 0;
while (c < end) {
switch (*c) {
case '"':
- extraSpaceNeeded += ArrayLength("&quot;") - 2;
- break;
case '&':
- extraSpaceNeeded += ArrayLength("&amp;") - 2;
- break;
case 0x00A0:
- extraSpaceNeeded += ArrayLength("&nbsp;") - 2;
+ ++numEncodedChars;
break;
default:
break;
@@ -9262,19 +9262,33 @@ static uint32_t ExtraSpaceNeededForAttrEncoding(const nsAString& aValue) {
++c;
}
- return extraSpaceNeeded;
+ if (!numEncodedChars) {
+ return 0;
+ }
+
+ // For simplicity, conservatively estimate the size of the string after
+ // encoding. This will result in reserving more memory than we actually
+ // need, but that should be fine unless the string has an enormous number of
+ // & in it. We subtract 1 for the null terminator, then 1 more for the
+ // existing character that will be replaced.
+ constexpr uint32_t maxCharExtraSpace =
+ std::max({ArrayLength("&quot;"), ArrayLength("&amp;"),
+ ArrayLength("&nbsp;")}) -
+ 2;
+ static_assert(maxCharExtraSpace < 100, "Possible underflow");
+ return CheckedInt<uint32_t>(numEncodedChars) * maxCharExtraSpace;
}
static void AppendEncodedAttributeValue(const nsAttrValue& aValue,
StringBuilder& aBuilder) {
if (nsAtom* atom = aValue.GetStoredAtom()) {
nsDependentAtomString atomStr(atom);
- uint32_t space = ExtraSpaceNeededForAttrEncoding(atomStr);
- if (!space) {
+ auto space = ExtraSpaceNeededForAttrEncoding(atomStr);
+ if (space.isValid() && !space.value()) {
aBuilder.Append(atom);
} else {
aBuilder.AppendWithAttrEncode(nsString(atomStr),
- atomStr.Length() + space);
+ space + atomStr.Length());
}
return;
}
@@ -9282,9 +9296,9 @@ static void AppendEncodedAttributeValue(const nsAttrValue& aValue,
// nsStringBuffer.
nsString str;
aValue.ToString(str);
- uint32_t space = ExtraSpaceNeededForAttrEncoding(str);
- if (space) {
- aBuilder.AppendWithAttrEncode(std::move(str), str.Length() + space);
+ auto space = ExtraSpaceNeededForAttrEncoding(str);
+ if (!space.isValid() || space.value()) {
+ aBuilder.AppendWithAttrEncode(std::move(str), space + str.Length());
} else {
aBuilder.Append(std::move(str));
}