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LibJS+Everywhere: Return strings by value from PrimitiveString

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It turns out return a ThrowCompletionOr<T const&> is flawed, as the GCC
expansion trick used with TRY will always make a copy. PrimitiveString
is luckily the only such use case.
This commit is contained in:
Timothy Flynn 2023-01-13 15:33:31 -05:00 • committed by Tim Flynn
parent 9a120d7243
commit a59ebdac2d
10 changed files with 22 additions and 21 deletions
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15
Userland/Libraries/LibJS/Runtime/PrimitiveString.cpp
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@ -64,7 +64,7 @@ bool PrimitiveString::is_empty() const
VERIFY_NOT_REACHED();
}
ThrowCompletionOr<DeprecatedString const&> PrimitiveString::deprecated_string() const
ThrowCompletionOr<DeprecatedString> PrimitiveString::deprecated_string() const
{
TRY(resolve_rope_if_needed());
@ -76,7 +76,7 @@ ThrowCompletionOr<DeprecatedString const&> PrimitiveString::deprecated_string()
return *m_utf8_string;
}
ThrowCompletionOr<Utf16String const&> PrimitiveString::utf16_string() const
ThrowCompletionOr<Utf16String> PrimitiveString::utf16_string() const
{
TRY(resolve_rope_if_needed());
@ -90,7 +90,8 @@ ThrowCompletionOr<Utf16String const&> PrimitiveString::utf16_string() const
ThrowCompletionOr<Utf16View> PrimitiveString::utf16_string_view() const
{
return TRY(utf16_string()).view();
(void)TRY(utf16_string());
return m_utf16_string->view();
}
ThrowCompletionOr<Optional<Value>> PrimitiveString::get(VM& vm, PropertyKey const& property_key) const
@ -178,8 +179,8 @@ ThrowCompletionOr<void> PrimitiveString::resolve_rope_if_needed() const
// NOTE: Special case for two concatenated UTF-16 strings.
// This is here as an optimization, although I'm unsure how valuable it is.
if (m_lhs->has_utf16_string() && m_rhs->has_utf16_string()) {
auto const& lhs_string = TRY(m_lhs->utf16_string());
auto const& rhs_string = TRY(m_rhs->utf16_string());
auto const& lhs_string = m_lhs->m_utf16_string.value();
auto const& rhs_string = m_rhs->m_utf16_string.value();
Utf16Data combined;
TRY_OR_THROW_OOM(vm, combined.try_ensure_capacity(lhs_string.length_in_code_units() + rhs_string.length_in_code_units()));
@ -226,8 +227,8 @@ ThrowCompletionOr<void> PrimitiveString::resolve_rope_if_needed() const
}
// Get the UTF-8 representations for both strings.
auto const& previous_string_as_utf8 = TRY(previous->deprecated_string());
auto const& current_string_as_utf8 = TRY(current->deprecated_string());
auto previous_string_as_utf8 = TRY(previous->deprecated_string());
auto current_string_as_utf8 = TRY(current->deprecated_string());
// NOTE: Now we need to look at the end of the previous string and the start
// of the current string, to see if they should be combined into a surrogate.