webkitgtk-2.10.2webkitgtk-2.10.2

1 files changed, 155 insertions, 0 deletions

diff --git a/Source/JavaScriptCore/parser/ModuleAnalyzer.cpp b/Source/JavaScriptCore/parser/ModuleAnalyzer.cpp
new file mode 100644
index 000000000..b2de960b3
--- /dev/null
+++ b/Source/JavaScriptCore/parser/ModuleAnalyzer.cpp
@@ -0,0 +1,155 @@
+/*
+ * Copyright (C) 2015 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "ModuleAnalyzer.h"
+
+#include "IdentifierInlines.h"
+#include "ModuleRecord.h"
+
+namespace JSC {
+
+
+ModuleAnalyzer::ModuleAnalyzer(VM& vm, const VariableEnvironment& declaredVariables, const VariableEnvironment& lexicalVariables)
+    : m_vm(&vm)
+    , m_moduleRecord(ModuleRecord::create())
+    , m_declaredVariables(declaredVariables)
+    , m_lexicalVariables(lexicalVariables)
+{
+}
+
+Identifier ModuleAnalyzer::exportedBinding(const RefPtr<UniquedStringImpl>& ident)
+{
+    const auto iterator = m_aliasMap.find(ident);
+    if (iterator != m_aliasMap.end())
+        return iterator->value;
+    return Identifier::fromUid(&vm(), ident.get());
+}
+
+void ModuleAnalyzer::declareExportAlias(const Identifier& localName, const Identifier& exportName)
+{
+    m_aliasMap.add(localName.impl(), exportName);
+}
+
+void ModuleAnalyzer::exportVariable(const RefPtr<UniquedStringImpl>& localName, const VariableEnvironmentEntry& variable)
+{
+    // In the parser, we already marked the variables as Exported and Imported.
+    // By leveraging this information, we collect the information that is needed
+    // to construct the module environment.
+    //
+    // I E
+    //   * = exported module local variable
+    // *   = imported binding
+    //     = non-exported module local variable
+    // * * = indirect exported binding
+    //
+    // One exception is namespace binding (like import * as ns from "mod").
+    // This is annotated as an imported, but the actual binding is locate in the
+    // current module.
+
+    if (!variable.isExported())
+        return;
+
+    const Identifier exportName = exportedBinding(localName);
+
+    // Exported module local variable.
+    if (!variable.isImported()) {
+        moduleRecord().addExportEntry(ModuleRecord::ExportEntry::createLocal(exportName, Identifier::fromUid(m_vm, localName.get()), variable));
+        return;
+    }
+
+    const auto& importEntry = moduleRecord().lookUpImportEntry(localName);
+    if (importEntry.isNamespace(vm())) {
+        // Exported namespace binding.
+        // import * as namespace from "mod"
+        // export { namespace }
+        moduleRecord().addExportEntry(ModuleRecord::ExportEntry::createNamespace(exportName, importEntry.moduleRequest));
+        return;
+    }
+
+    // Indirectly exported binding.
+    // import a from "mod"
+    // export { a }
+    moduleRecord().addExportEntry(ModuleRecord::ExportEntry::createIndirect(exportName, importEntry.importName, importEntry.moduleRequest));
+}
+
+
+
+Ref<ModuleRecord> ModuleAnalyzer::analyze(ModuleProgramNode& moduleProgramNode)
+{
+    // Traverse the module AST and collect
+    // * Import entries
+    // * Export entries that have FromClause (e.g. export { a } from "mod")
+    // * Export entries that have star (e.g. export * from "mod")
+    // * Aliased export names (e.g. export { a as b })
+    moduleProgramNode.analyzeModule(*this);
+
+    // Based on the collected information, categorize export entries into 3 types.
+    // 1. Local export entries
+    //     This references the local variable in the current module.
+    //     This variable should be allocated in the current module environment as a heap variable.
+    //
+    //     const variable = 20
+    //     export { variable }
+    //
+    // 2. Namespace export entries
+    //     This references the namespace object imported by some import entries.
+    //     This variable itself should be allocated in the current module environment as a heap variable.
+    //     But when the other modules attempt to resolve this export name in this module, this module
+    //     should tell the link to the original module.
+    //
+    //     import * as namespace from "mod"
+    //     export { namespace as mod }
+    //
+    // 3. Indirect export entries
+    //     This references the imported binding name from the other module.
+    //     This module environment itself should hold the pointer to (1) the original module and
+    //     (2) the binding in the original module. The variable itself is allocated in the original
+    //     module. This indirect binding is resolved when the CodeBlock resolves the references.
+    //
+    //     import mod from "mod"
+    //     export { mod }
+    //
+    //     export { a } from "mod"
+    //
+    // And separeted from the above 3 types, we also collect the star export entries.
+    //
+    // 4. Star export entries
+    //     This exports all the names from the specified external module as the current module's name.
+    //
+    //     export * from "mod"
+    for (const auto& pair : m_declaredVariables)
+        exportVariable(pair.key, pair.value);
+
+    for (const auto& pair : m_lexicalVariables)
+        exportVariable(pair.key, pair.value);
+
+    if (Options::dumpModuleRecord())
+        m_moduleRecord->dump();
+
+    return *m_moduleRecord;
+}
+
+} // namespace JSC