Bug 138252 – Add scope operand to op_push_with_scope, op_push_name_scope and op_pop_scope

• Component: JavaScriptCore
• Status: RESOLVED FIXED

[Michael Saboff]

This is part of the effort to remove the scope chain from the call frame header (https://bugs.webkit.org/show_bug.cgi?id=136724).

This bug is to add a source scope register index to the op_push_with_scope, op_push_name_scope and op_pop_scope byte codes.  The new operand will be filled in but not used.

[Michael Saboff]

Created attachment 240746 [details]
Patch

[Geoffrey Garen]

Comment on attachment 240746 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=240746&action=review

> Source/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp:2199
> +void BytecodeGenerator::emitComplexPopScopes(RegisterID* scopeReg, ControlFlowContext* topScope, ControlFlowContext* bottomScope)

Let's call this "scope", or, if we need to disambiguate from something else named "scope", then "scopeRegister".

> Source/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp:2314
> +void BytecodeGenerator::emitPopScopes(RegisterID* scopeReg, int targetScopeDepth)

Ditto.

> Source/JavaScriptCore/bytecompiler/BytecodeGenerator.h:543
> +        void emitPopScope(RegisterID* scopeReg);

This should be "srcDst" to match other functions' naming.

> Source/JavaScriptCore/bytecompiler/NodesCodegen.cpp:2253
> +    RegisterID scopeDest(JSStack::ScopeChain);

Let's make the scope register a data member in the BytecodeGenerator instead of a one-off allocation at the call site. It's not really valid to allocate bytecode registers in this way.

[Michael Saboff]

Created attachment 240749 [details]
Patch with suggested updates

[Geoffrey Garen]

Comment on attachment 240749 [details]
Patch with suggested updates

r=me

[Michael Saboff]

Committed r175426: <http://trac.webkit.org/changeset/175426>