This change adds a pass over the AST that computes the
set of assigned variables for locals and parameters for each expression.
The result of this analysis is used to for two purposes:
1. Recognize variables that are trivial subexpressions. A left sub-expression
of a binary operation is trivial if it is a local variable or a parameter
and it is not assigned in the right sub-expression. In the case of a
trivial left sub-expression we evaluate the right first.
Currently only binary operations and compare operations are considered
when finding trivial left sub-expressions.
2. Recogize certain simple for-loops with a constant trip count where the loop
variable is always within smi range. If the loop count variable is not
assigned in the body of the loop (except in the update expression the
for-loop). This allows omitting smi checks on operation using the loop
count variable.
Review URL: http://codereview.chromium.org/669155
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4087 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Make sure that the DummyScope top level scope used for pre-parsing have all members initialized. The type of this scope is set to global scope as it is a top level scope. Also ensure that the "naked" Scope constructor can only be used by sub-classes of Scope.
The bug of missing initiaalization of members in the DummyScope was found by Valgrind.
Review URL: http://codereview.chromium.org/173052
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2719 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
variable object.
Add a map from names to variables for global scopes just like
non-global scopes. Variables are added to the map by the parser when
it encounters a declaration in a global scope or else at scope
resolution time by a failed variable lookup from the global scope or
an inner one and with no intervening with statements or possible calls
to eval.
Review URL: http://codereview.chromium.org/149245
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2369 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This issue was raised by Brett Wilson while reviewing my changelist for readability. Craig Silverstein (one of C++ SG maintainers) confirmed that we should declare one namespace per line. Our way of namespaces closing seems not violating style guides (there is no clear agreement on it), so I left it intact.
Review URL: http://codereview.chromium.org/115756
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2038 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
surrounding context to figure out if the variable could be global. If
the variable could be global we check context extension objects at
runtime and use a global LoadIC if no variables have been introduced
by eval.
Fix crash bug when loading function arguments from inside eval. The
shadowed variable in the DYNAMIC_LOCAL case does not rewrite to a slot in
that case.
Review URL: http://codereview.chromium.org/28027
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1348 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
introduced by eval.
In the cases where calls to eval have not introduced any variables, we
do not need to perform a runtime call. Instead, we verify that the
context extension objects have not been created and perform a direct
load.
Not implemented for ARM yet and the scope resolution code could use
some better abstractions. I'd like to do that in a separate
changelist.
Review URL: http://codereview.chromium.org/20419
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1298 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
