16d9298a9c
Origin trials allow webpages to use experimental features even though the features are not yet enabled by default. These features will then get enabled per execution context: it is possible that the feature is enabled in one execution context but disabled in another execution context. In V8 we check for origin trials by calling a callback provided by the embedder that takes the context as a parameter and returns whether a feature is enabled in this context or not. This approach fails when a feature changes the context itself, e.g. by extending the global object. In that case the context is not available yet to check for the origin trial. To solve the problem this CL adds a new API function that can be called by the embedder to notify V8 that context with the origin trial information is finished. After that V8 can read the origin trial information from the context and extend e.g. the global object with the origin trial features. Additionally to the API this CL also adds code to enable the WebAssembly.Exception constructor conditionally, depending on whether it has been enabled by an origin trial or not. The Blink-side change: https://crrev.com/c/2775573 R=ulan@chromium.org, jkummerow@chromium.org Change-Id: Ic05c4a89eb3e0e31469e49da8767d630c43b2e00 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2773287 Reviewed-by: Andreas Haas <ahaas@chromium.org> Reviewed-by: Ulan Degenbaev <ulan@chromium.org> Reviewed-by: Jakob Kummerow <jkummerow@chromium.org> Commit-Queue: Andreas Haas <ahaas@chromium.org> Cr-Commit-Position: refs/heads/master@{#73597}
85 lines
2.4 KiB
C++
85 lines
2.4 KiB
C++
// Copyright 2018 the V8 project authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#if !V8_ENABLE_WEBASSEMBLY
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#error This header should only be included if WebAssembly is enabled.
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#endif // !V8_ENABLE_WEBASSEMBLY
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#ifndef V8_WASM_WASM_FEATURES_H_
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#define V8_WASM_WASM_FEATURES_H_
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// The feature flags are declared in their own header.
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#include "src/base/enum-set.h"
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#include "src/base/macros.h"
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#include "src/wasm/wasm-feature-flags.h"
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// All features, including features that do not have flags.
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#define FOREACH_WASM_FEATURE FOREACH_WASM_FEATURE_FLAG
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namespace v8 {
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namespace internal {
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class Context;
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template <typename T>
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class Handle;
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class Isolate;
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namespace wasm {
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enum WasmFeature {
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#define DECL_FEATURE_ENUM(feat, ...) kFeature_##feat,
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FOREACH_WASM_FEATURE(DECL_FEATURE_ENUM)
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#undef DECL_FEATURE_ENUM
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};
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// Enabled or detected features.
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class WasmFeatures : public base::EnumSet<WasmFeature> {
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public:
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constexpr WasmFeatures() = default;
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explicit constexpr WasmFeatures(std::initializer_list<WasmFeature> features)
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: EnumSet(features) {}
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// Simplified getters. Use {has_foo()} instead of {contains(kFeature_foo)}.
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#define DECL_FEATURE_GETTER(feat, ...) \
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constexpr bool has_##feat() const { return contains(kFeature_##feat); }
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FOREACH_WASM_FEATURE(DECL_FEATURE_GETTER)
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#undef DECL_FEATURE_GETTER
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static constexpr const char* name_for_feature(WasmFeature feature) {
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switch (feature) {
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#define NAME(feat, ...) \
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case WasmFeature::kFeature_##feat: \
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return #feat;
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FOREACH_WASM_FEATURE(NAME)
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}
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#undef NAME
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}
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static inline constexpr WasmFeatures All();
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static inline constexpr WasmFeatures None();
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static inline constexpr WasmFeatures ForAsmjs();
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static WasmFeatures FromFlags();
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static V8_EXPORT_PRIVATE WasmFeatures FromIsolate(Isolate*);
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static V8_EXPORT_PRIVATE WasmFeatures FromContext(Isolate*,
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Handle<Context> context);
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};
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// static
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constexpr WasmFeatures WasmFeatures::All() {
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#define LIST_FEATURE(feat, ...) kFeature_##feat,
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return WasmFeatures({FOREACH_WASM_FEATURE(LIST_FEATURE)});
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#undef LIST_FEATURE
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}
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// static
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constexpr WasmFeatures WasmFeatures::None() { return {}; }
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// static
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constexpr WasmFeatures WasmFeatures::ForAsmjs() { return {}; }
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} // namespace wasm
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} // namespace internal
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} // namespace v8
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#endif // V8_WASM_WASM_FEATURES_H_
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