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/* -*- 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/. */
#include "util/DefaultLocale.h"
#include "mozilla/Assertions.h"
#if JS_HAS_INTL_API
# include "mozilla/intl/Locale.h"
#endif
#include "mozilla/Span.h"
#include <clocale>
#include <cstring>
#include <string_view>
#include "js/GCAPI.h"
#include "util/LanguageId.h"
using namespace js;
static std::string_view SystemDefaultLocale() {
#ifdef JS_HAS_INTL_API
// Use ICU if available to retrieve the default locale, this ensures ICU's
// default locale matches our default locale.
return mozilla::intl::Locale::GetDefaultLocale();
#else
const char* loc = std::setlocale(LC_ALL, nullptr);
// Convert to a well-formed BCP 47 language tag.
if (!loc || !std::strcmp(loc, "C")) {
loc = "und";
}
std::string_view locale{loc};
// Remove optional code page from the locale string.
return locale.substr(0, locale.find('.'));
#endif
}
#ifdef JS_HAS_INTL_API
/**
* Create a LanguageId from a `mozilla::intl::Locale`.
*/
static LanguageId ToLanguageId(const mozilla::intl::Locale& locale) {
MOZ_ASSERT(locale.Language().Length() <= 3, "unexpected overlong language");
auto toStringView = [](const auto& subtag) -> std::string_view {
auto span = subtag.Span();
return {span.data(), span.size()};
};
auto language = toStringView(locale.Language());
auto script = toStringView(locale.Script());
auto region = toStringView(locale.Region());
return LanguageId::fromParts(language, script, region);
}
/**
* Canonicalize a LanguageId using `mozilla::intl::Locale`.
*/
static auto CanonicalizeLocale(LanguageId langId) {
mozilla::intl::LanguageSubtag language{mozilla::Span{langId.language()}};
mozilla::intl::ScriptSubtag script{mozilla::Span{langId.script()}};
mozilla::intl::RegionSubtag region{mozilla::Span{langId.region()}};
mozilla::intl::Locale locale{};
locale.SetLanguage(language);
locale.SetScript(script);
locale.SetRegion(region);
auto result = locale.CanonicalizeBaseName();
MOZ_RELEASE_ASSERT(
result.isOk(),
"canonicalization is infallible when no variant subtags are present");
return ToLanguageId(locale);
}
#endif
LanguageId js::SystemDefaultLocale() {
// Tell the analysis this function can't GC. (bug 1588528)
JS::AutoSuppressGCAnalysis nogc;
auto parsed = LanguageId::fromId(::SystemDefaultLocale());
// Ignore any subtags after the (language, script, region) subtags triple.
if (parsed) {
#ifdef JS_HAS_INTL_API
// Return canonicalized locale if Intl API is available.
return CanonicalizeLocale(parsed->first);
#else
return parsed->first;
#endif
}
// Unknow system default locale.
return LanguageId::und();
}
LanguageId js::DefaultLocaleFrom(std::string_view localeId) {
// Tell the analysis this function can't GC. (bug 1588528)
JS::AutoSuppressGCAnalysis nogc;
auto parsed = LanguageId::fromBcp49(localeId);
#ifdef JS_HAS_INTL_API
// Handle the common case first:
// 1. The language, script, and region subtags are in canonical case.
// 2. No additional variant or extension subtags are present.
if (parsed && parsed->second == 0) {
// Return canonicalized locale if Intl API is available.
return CanonicalizeLocale(parsed->first);
}
// Slow path: Use the LocaleParser to parse and validate the complete input.
mozilla::intl::Locale locale;
bool canParseLocale = mozilla::intl::LocaleParser::TryParse(
mozilla::Span<const char>{localeId}, locale)
.isOk();
if (canParseLocale) {
// Remove variant subtags, because no available ICU locale contains any.
locale.ClearVariants();
auto result = locale.CanonicalizeBaseName();
MOZ_RELEASE_ASSERT(
result.isOk(),
"canonicalization is infallible when no variant subtags are present");
// Reject overlong language subtags which don't fit into `LanguageId`.
if (locale.Language().Length() <= 3) {
return ToLanguageId(locale);
}
}
#else
// We don't perform any additional validation when the Intl API is disabled.
if (parsed) {
return parsed->first;
}
#endif
// Unparseable Unicode BCP 47 locale identifier.
return LanguageId::und();
}