summaryrefslogtreecommitdiffstats
path: root/js/src/wasm/WasmInitExpr.h
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
commit36d22d82aa202bb199967e9512281e9a53db42c9 (patch)
tree105e8c98ddea1c1e4784a60a5a6410fa416be2de /js/src/wasm/WasmInitExpr.h
parentInitial commit. (diff)
downloadfirefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz
firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'js/src/wasm/WasmInitExpr.h')
-rw-r--r--js/src/wasm/WasmInitExpr.h101
1 files changed, 101 insertions, 0 deletions
diff --git a/js/src/wasm/WasmInitExpr.h b/js/src/wasm/WasmInitExpr.h
new file mode 100644
index 0000000000..385f1c6b66
--- /dev/null
+++ b/js/src/wasm/WasmInitExpr.h
@@ -0,0 +1,101 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ *
+ * Copyright 2021 Mozilla Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef wasm_initexpr_h
+#define wasm_initexpr_h
+
+#include "wasm/WasmConstants.h"
+#include "wasm/WasmSerialize.h"
+#include "wasm/WasmTypeDecls.h"
+#include "wasm/WasmValType.h"
+#include "wasm/WasmValue.h"
+
+namespace js {
+namespace wasm {
+
+class Decoder;
+struct ModuleEnvironment;
+
+enum class InitExprKind {
+ None,
+ Literal,
+ Variable,
+};
+
+// A InitExpr describes a deferred initializer expression, used to initialize
+// a global or a table element offset. Such expressions are created during
+// decoding and actually executed on module instantiation.
+
+class InitExpr {
+ InitExprKind kind_;
+ // The bytecode for this constant expression if this is not a literal.
+ Bytes bytecode_;
+ // The value if this is a literal.
+ LitVal literal_;
+ // The value type of this constant expression in either case.
+ ValType type_;
+
+ public:
+ InitExpr() : kind_(InitExprKind::None) {}
+
+ explicit InitExpr(LitVal literal)
+ : kind_(InitExprKind::Literal),
+ literal_(literal),
+ type_(literal.type()) {}
+
+ // Decode and validate a constant expression given at the current
+ // position of the decoder. Upon failure, the decoder contains the failure
+ // message or else the failure was an OOM.
+ static bool decodeAndValidate(Decoder& d, ModuleEnvironment* env,
+ ValType expected,
+ uint32_t maxInitializedGlobalsIndexPlus1,
+ InitExpr* expr);
+
+ // Evaluate the constant expresssion with the given context. This may only
+ // fail due to an OOM, as all InitExpr's are required to have been validated.
+ bool evaluate(JSContext* cx, Handle<WasmInstanceObject*> instanceObj,
+ MutableHandleVal result) const;
+
+ bool isLiteral() const { return kind_ == InitExprKind::Literal; }
+
+ // Gets the result of this expression if it was determined to be a literal.
+ LitVal literal() const {
+ MOZ_ASSERT(isLiteral());
+ return literal_;
+ }
+
+ // Get the type of the resulting value of this expression.
+ ValType type() const { return type_; }
+
+ // Allow moving, but not implicit copying
+ InitExpr(const InitExpr&) = delete;
+ InitExpr& operator=(const InitExpr&) = delete;
+ InitExpr(InitExpr&&) = default;
+ InitExpr& operator=(InitExpr&&) = default;
+
+ // Allow explicit cloning
+ [[nodiscard]] bool clone(const InitExpr& src);
+
+ size_t sizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
+ WASM_DECLARE_FRIEND_SERIALIZE(InitExpr);
+};
+
+} // namespace wasm
+} // namespace js
+
+#endif // wasm_initexpr_h