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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 14:29:10 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 14:29:10 +0000 |
commit | 2aa4a82499d4becd2284cdb482213d541b8804dd (patch) | |
tree | b80bf8bf13c3766139fbacc530efd0dd9d54394c /js/src/frontend/ForOfLoopControl.h | |
parent | Initial commit. (diff) | |
download | firefox-2aa4a82499d4becd2284cdb482213d541b8804dd.tar.xz firefox-2aa4a82499d4becd2284cdb482213d541b8804dd.zip |
Adding upstream version 86.0.1.upstream/86.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'js/src/frontend/ForOfLoopControl.h')
-rw-r--r-- | js/src/frontend/ForOfLoopControl.h | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/js/src/frontend/ForOfLoopControl.h b/js/src/frontend/ForOfLoopControl.h new file mode 100644 index 0000000000..dec7737fd6 --- /dev/null +++ b/js/src/frontend/ForOfLoopControl.h @@ -0,0 +1,98 @@ +/* -*- 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/. */ + +#ifndef frontend_ForOfLoopControl_h +#define frontend_ForOfLoopControl_h + +#include "mozilla/Attributes.h" // MOZ_MUST_USE +#include "mozilla/Maybe.h" // mozilla::Maybe + +#include <stdint.h> // int32_t, uint32_t + +#include "jsapi.h" // CompletionKind + +#include "frontend/BytecodeControlStructures.h" // NestableControl, LoopControl +#include "frontend/BytecodeOffset.h" // BytecodeOffset +#include "frontend/IteratorKind.h" // IteratorKind +#include "frontend/TryEmitter.h" // TryEmitter + +namespace js { +namespace frontend { + +struct BytecodeEmitter; +class EmitterScope; + +class ForOfLoopControl : public LoopControl { + // The stack depth of the iterator. + int32_t iterDepth_; + + // for-of loops, when throwing from non-iterator code (i.e. from the body + // or from evaluating the LHS of the loop condition), need to call + // IteratorClose. This is done by enclosing non-iterator code with + // try-catch and call IteratorClose in `catch` block. + // If IteratorClose itself throws, we must not re-call IteratorClose. Since + // non-local jumps like break and return call IteratorClose, whenever a + // non-local jump is emitted, we must tell catch block not to perform + // IteratorClose. + // + // for (x of y) { + // // Operations for iterator (IteratorNext etc) are outside of + // // try-block. + // try { + // ... + // if (...) { + // // Before non-local jump, clear iterator on the stack to tell + // // catch block not to perform IteratorClose. + // tmpIterator = iterator; + // iterator = undefined; + // IteratorClose(tmpIterator, { break }); + // break; + // } + // ... + // } catch (e) { + // // Just throw again when iterator is cleared by non-local jump. + // if (iterator === undefined) + // throw e; + // IteratorClose(iterator, { throw, e }); + // } + // } + mozilla::Maybe<TryEmitter> tryCatch_; + + // Used to track if any yields were emitted between calls to to + // emitBeginCodeNeedingIteratorClose and emitEndCodeNeedingIteratorClose. + uint32_t numYieldsAtBeginCodeNeedingIterClose_; + + bool allowSelfHosted_; + + IteratorKind iterKind_; + + public: + ForOfLoopControl(BytecodeEmitter* bce, int32_t iterDepth, + bool allowSelfHosted, IteratorKind iterKind); + + MOZ_MUST_USE bool emitBeginCodeNeedingIteratorClose(BytecodeEmitter* bce); + MOZ_MUST_USE bool emitEndCodeNeedingIteratorClose(BytecodeEmitter* bce); + + MOZ_MUST_USE bool emitIteratorCloseInInnermostScopeWithTryNote( + BytecodeEmitter* bce, + CompletionKind completionKind = CompletionKind::Normal); + MOZ_MUST_USE bool emitIteratorCloseInScope( + BytecodeEmitter* bce, EmitterScope& currentScope, + CompletionKind completionKind = CompletionKind::Normal); + + MOZ_MUST_USE bool emitPrepareForNonLocalJumpFromScope( + BytecodeEmitter* bce, EmitterScope& currentScope, bool isTarget, + BytecodeOffset* tryNoteStart); +}; +template <> +inline bool NestableControl::is<ForOfLoopControl>() const { + return kind_ == StatementKind::ForOfLoop; +} + +} /* namespace frontend */ +} /* namespace js */ + +#endif /* frontend_ForOfLoopControl_h */ |