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Diffstat (limited to 'js/src/frontend/BytecodeCompiler.h')
| -rw-r--r-- | js/src/frontend/BytecodeCompiler.h | 291 |
1 files changed, 291 insertions, 0 deletions
diff --git a/js/src/frontend/BytecodeCompiler.h b/js/src/frontend/BytecodeCompiler.h new file mode 100644 index 0000000000..6576e23519 --- /dev/null +++ b/js/src/frontend/BytecodeCompiler.h @@ -0,0 +1,291 @@ +/* -*- 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_BytecodeCompiler_h +#define frontend_BytecodeCompiler_h + +#include "mozilla/AlreadyAddRefed.h" // already_AddRefed +#include "mozilla/Maybe.h" // mozilla::Maybe +#include "mozilla/Utf8.h" // mozilla::Utf8Unit + +#include <stdint.h> // uint32_t + +#include "ds/LifoAlloc.h" // js::LifoAlloc +#include "frontend/FunctionSyntaxKind.h" // FunctionSyntaxKind +#include "frontend/ScriptIndex.h" // ScriptIndex +#include "js/CompileOptions.h" // JS::ReadOnlyCompileOptions, JS::PrefableCompileOptions +#include "js/GCVector.h" // JS::StackGCVector +#include "js/Id.h" // JS::PropertyKey +#include "js/RootingAPI.h" // JS::Handle +#include "js/SourceText.h" // JS::SourceText +#include "js/UniquePtr.h" // js::UniquePtr +#include "js/Value.h" // JS::Value +#include "vm/ScopeKind.h" // js::ScopeKind + +/* + * Structure of all of the support classes. + * + * Parser: described in Parser.h. + * + * BytecodeCompiler.cpp: BytecodeCompiler.h + * This is the "driver", the high-level operations like "compile this source to + * bytecode". It calls the parser, bytecode emitter, etc. + * + * ParseContext.h and SharedContext.h: Both have similar purposes. They're split + * because ParseContext contains information used only by the parser, and + * SharedContext contains information used by both the parser and + * BytecodeEmitter. + * + * SharedContext.h: class Directives: this contains boolean flags for tracking + * if we're in asm.js or "use strict" code. The "use strict" bit is stored in + * SharedContext, and additionally, the full Directives class is stored in + * ParseContext - if a direcive is encountered while parsing, this is updated, + * and checked in GeneralParser::functionDefinition, and if it changed, the + * whole function is re-parsed with the new flags. + * + * SharedContext.h: abstract class SharedContext: This class contains two + * different groups of flags: + * + * Parse context information. This is information conceptually "passed down" + * into parsing sub-nodes. This is like "are we parsing strict code?", and so + * the parser can make decisions of how to parse based off that. + * + * Gathered-while-parsing information. This is information conceptually + * "returned up" from parsing sub-nodes. This is like "did we see a use strict + * directive"? + * + * Additionally, subclasses (GlobalSharedContext, ModuleSharedContext, + * EvalSharedContext, and FunctionBox) contain binding information, scope + * information, and other such bits of data. + * + * ParseContext.h: class UsedNameTracker: Track which bindings are used in which + * scopes. This helps determine which bindings are closed-over, which affects + * how they're stored; and whether special bindings like `this` and `arguments` + * can be optimized away. + * + * ParseContext.h: class ParseContext: Extremely complex class that serves a lot + * of purposes, but it's a single class - essentially no derived classes - so + * it's a little easier to comprehend all at once. (SourceParseContext does + * derive from ParseContext, but they does nothing except adjust the + * constructor's arguments). + * Note it uses a thing called Nestable, which implements a stack of objects: + * you can push (and pop) instances to a stack (linked list) as you parse + * further into the parse tree. You may push to this stack via calling the + * constructor with a GeneralParser as an argument (usually `this`), which + * pushes itself onto `this->pc` (so it does get assigned/pushed, even though no + * assignment ever appears directly in the parser) + * + * ParseContext contains a pointer to a SharedContext. + * + * There's a decent chunk of flags/data collection in here too, some "pass-down" + * data and some "return-up" data. + * + * ParseContext also contains a significant number of *sub*-Nestables as fields + * of itself (nestables inside nestables). Note you also push/pop to these via + * passing `Parser->pc`, which the constructor of the sub-nestable knows which + * ParseContext field to push to. The sub-nestables are: + * + * ParseContext::Statement: stack of statements. + * `if (x) { while (true) { try { ..stack of [if, while, try].. } ... } }` + * + * ParseContext::LabelStatement: interspersed in Statement stack, for labeled + * statements, for e.g. `label: while (true) { break label; }` + * + * ParseContext::ClassStatement: interspersed in Statement stack, for classes + * the parser is currently inside of. + * + * ParseContext::Scope: Set of variables in each scope (stack of sets): + * `{ let a; let b; { let c; } }` + * (this gets complicated with `var`, etc., check the class for docs) + */ + +class JSFunction; +class JSObject; +class JSScript; +struct JSContext; + +namespace js { + +class ModuleObject; +class FrontendContext; +class Scope; + +namespace frontend { + +struct CompilationInput; +struct CompilationStencil; +struct ExtensibleCompilationStencil; +struct CompilationGCOutput; +class ScopeBindingCache; + +// Compile a script of the given source using the given options. +extern already_AddRefed<CompilationStencil> CompileGlobalScriptToStencil( + JSContext* maybeCx, FrontendContext* fc, js::LifoAlloc& tempLifoAlloc, + CompilationInput& input, ScopeBindingCache* scopeCache, + JS::SourceText<char16_t>& srcBuf, ScopeKind scopeKind); + +extern already_AddRefed<CompilationStencil> CompileGlobalScriptToStencil( + JSContext* maybeCx, FrontendContext* fc, js::LifoAlloc& tempLifoAlloc, + CompilationInput& input, ScopeBindingCache* scopeCache, + JS::SourceText<mozilla::Utf8Unit>& srcBuf, ScopeKind scopeKind); + +extern UniquePtr<ExtensibleCompilationStencil> +CompileGlobalScriptToExtensibleStencil(JSContext* maybeCx, FrontendContext* fc, + CompilationInput& input, + ScopeBindingCache* scopeCache, + JS::SourceText<char16_t>& srcBuf, + ScopeKind scopeKind); + +extern UniquePtr<ExtensibleCompilationStencil> +CompileGlobalScriptToExtensibleStencil( + JSContext* maybeCx, FrontendContext* fc, CompilationInput& input, + ScopeBindingCache* scopeCache, JS::SourceText<mozilla::Utf8Unit>& srcBuf, + ScopeKind scopeKind); + +[[nodiscard]] extern bool InstantiateStencils(JSContext* cx, + CompilationInput& input, + const CompilationStencil& stencil, + CompilationGCOutput& gcOutput); + +// Perform CompileGlobalScriptToStencil and InstantiateStencils at the +// same time, skipping some extra copy. +extern JSScript* CompileGlobalScript(JSContext* cx, FrontendContext* fc, + const JS::ReadOnlyCompileOptions& options, + JS::SourceText<char16_t>& srcBuf, + ScopeKind scopeKind); + +extern JSScript* CompileGlobalScript(JSContext* cx, FrontendContext* fc, + const JS::ReadOnlyCompileOptions& options, + JS::SourceText<mozilla::Utf8Unit>& srcBuf, + ScopeKind scopeKind); + +// Compile a script with a list of known extra bindings. +// +// Bindings should be passed by a pair of unwrappedBindingKeys and +// unwrappedBindingValues. +// +// If any of the bindings are accessed by the script, a WithEnvironmentObject +// is created for the bindings and returned via env out parameter. Otherwise, +// global lexical is returned. In both case, the same env must be used to +// evaluate the script. +// +// Both unwrappedBindingKeys and unwrappedBindingValues can come from different +// realm than the current realm. +// +// If a binding is shadowed by the global variables declared by the script, +// or the existing global variables, the binding is not stored into the +// resulting WithEnvironmentObject. +extern JSScript* CompileGlobalScriptWithExtraBindings( + JSContext* cx, FrontendContext* fc, + const JS::ReadOnlyCompileOptions& options, JS::SourceText<char16_t>& srcBuf, + JS::Handle<JS::StackGCVector<JS::PropertyKey>> unwrappedBindingKeys, + JS::Handle<JS::StackGCVector<JS::Value>> unwrappedBindingValues, + JS::MutableHandle<JSObject*> env); + +// Compile a script for eval of the given source using the given options and +// enclosing scope/environment. +extern JSScript* CompileEvalScript(JSContext* cx, + const JS::ReadOnlyCompileOptions& options, + JS::SourceText<char16_t>& srcBuf, + JS::Handle<js::Scope*> enclosingScope, + JS::Handle<JSObject*> enclosingEnv); + +// Compile a module of the given source using the given options. +ModuleObject* CompileModule(JSContext* cx, FrontendContext* fc, + const JS::ReadOnlyCompileOptions& options, + JS::SourceText<char16_t>& srcBuf); +ModuleObject* CompileModule(JSContext* cx, FrontendContext* fc, + const JS::ReadOnlyCompileOptions& options, + JS::SourceText<mozilla::Utf8Unit>& srcBuf); + +// Parse a module of the given source. This is an internal API; if you want to +// compile a module as a user, use CompileModule above. +already_AddRefed<CompilationStencil> ParseModuleToStencil( + JSContext* maybeCx, FrontendContext* fc, js::LifoAlloc& tempLifoAlloc, + CompilationInput& input, ScopeBindingCache* scopeCache, + JS::SourceText<char16_t>& srcBuf); +already_AddRefed<CompilationStencil> ParseModuleToStencil( + JSContext* maybeCx, FrontendContext* fc, js::LifoAlloc& tempLifoAlloc, + CompilationInput& input, ScopeBindingCache* scopeCache, + JS::SourceText<mozilla::Utf8Unit>& srcBuf); + +UniquePtr<ExtensibleCompilationStencil> ParseModuleToExtensibleStencil( + JSContext* cx, FrontendContext* fc, js::LifoAlloc& tempLifoAlloc, + CompilationInput& input, ScopeBindingCache* scopeCache, + JS::SourceText<char16_t>& srcBuf); +UniquePtr<ExtensibleCompilationStencil> ParseModuleToExtensibleStencil( + JSContext* cx, FrontendContext* fc, js::LifoAlloc& tempLifoAlloc, + CompilationInput& input, ScopeBindingCache* scopeCache, + JS::SourceText<mozilla::Utf8Unit>& srcBuf); + +// +// Compile a single function. The source in srcBuf must match the ECMA-262 +// FunctionExpression production. +// +// If nonzero, parameterListEnd is the offset within srcBuf where the parameter +// list is expected to end. During parsing, if we find that it ends anywhere +// else, it's a SyntaxError. This is used to implement the Function constructor; +// it's how we detect that these weird cases are SyntaxErrors: +// +// Function("/*", "*/x) {") +// Function("x){ if (3", "return x;}") +// +[[nodiscard]] JSFunction* CompileStandaloneFunction( + JSContext* cx, const JS::ReadOnlyCompileOptions& options, + JS::SourceText<char16_t>& srcBuf, + const mozilla::Maybe<uint32_t>& parameterListEnd, + frontend::FunctionSyntaxKind syntaxKind); + +[[nodiscard]] JSFunction* CompileStandaloneGenerator( + JSContext* cx, const JS::ReadOnlyCompileOptions& options, + JS::SourceText<char16_t>& srcBuf, + const mozilla::Maybe<uint32_t>& parameterListEnd, + frontend::FunctionSyntaxKind syntaxKind); + +[[nodiscard]] JSFunction* CompileStandaloneAsyncFunction( + JSContext* cx, const JS::ReadOnlyCompileOptions& options, + JS::SourceText<char16_t>& srcBuf, + const mozilla::Maybe<uint32_t>& parameterListEnd, + frontend::FunctionSyntaxKind syntaxKind); + +[[nodiscard]] JSFunction* CompileStandaloneAsyncGenerator( + JSContext* cx, const JS::ReadOnlyCompileOptions& options, + JS::SourceText<char16_t>& srcBuf, + const mozilla::Maybe<uint32_t>& parameterListEnd, + frontend::FunctionSyntaxKind syntaxKind); + +// Compile a single function in given enclosing non-syntactic scope. +[[nodiscard]] JSFunction* CompileStandaloneFunctionInNonSyntacticScope( + JSContext* cx, const JS::ReadOnlyCompileOptions& options, + JS::SourceText<char16_t>& srcBuf, + const mozilla::Maybe<uint32_t>& parameterListEnd, + frontend::FunctionSyntaxKind syntaxKind, JS::Handle<Scope*> enclosingScope); + +extern bool DelazifyCanonicalScriptedFunction(JSContext* cx, + FrontendContext* fc, + JS::Handle<JSFunction*> fun); + +enum class DelazifyFailureReason { + Compressed, + Other, +}; + +extern already_AddRefed<CompilationStencil> DelazifyCanonicalScriptedFunction( + FrontendContext* fc, js::LifoAlloc& tempLifoAlloc, + const JS::PrefableCompileOptions& prefableOptions, + ScopeBindingCache* scopeCache, CompilationStencil& context, + ScriptIndex scriptIndex, DelazifyFailureReason* failureReason); + +// Certain compile options will disable the syntax parser entirely. +inline bool CanLazilyParse(const JS::ReadOnlyCompileOptions& options) { + return !options.discardSource && !options.sourceIsLazy && + !options.forceFullParse(); +} + +} /* namespace frontend */ +} /* namespace js */ + +#endif /* frontend_BytecodeCompiler_h */ |