Modules now have their own local scope, represented by their own context.
Module instance objects have an accessor for every export that forwards
access to the respective slot from the module's context. (Exports that are
modules themselves, however, are simple data properties.)
All modules have a _hosting_ scope/context, which (currently) is the
(innermost) enclosing global scope. To deal with recursion, nested modules
are hosted by the same scope as global ones.
For every (global or nested) module literal, the hosting context has an
internal slot that points directly to the respective module context. This
enables quick access to (statically resolved) module members by 2-dimensional
access through the hosting context. For example,
module A {
let x;
module B { let y; }
}
module C { let z; }
allocates contexts as follows:
[header| .A | .B | .C | A | C ] (global)
| | |
| | +-- [header| z ] (module)
| |
| +------- [header| y ] (module)
|
+------------ [header| x | B ] (module)
Here, .A, .B, .C are the internal slots pointing to the hosted module
contexts, whereas A, B, C hold the actual instance objects (note that every
module context also points to the respective instance object through its
extension slot in the header).
To deal with arbitrary recursion and aliases between modules,
they are created and initialized in several stages. Each stage applies to
all modules in the hosting global scope, including nested ones.
1. Allocate: for each module _literal_, allocate the module contexts and
respective instance object and wire them up. This happens in the
PushModuleContext runtime function, as generated by AllocateModules
(invoked by VisitDeclarations in the hosting scope).
2. Bind: for each module _declaration_ (i.e. literals as well as aliases),
assign the respective instance object to respective local variables. This
happens in VisitModuleDeclaration, and uses the instance objects created
in the previous stage.
For each module _literal_, this phase also constructs a module descriptor
for the next stage. This happens in VisitModuleLiteral.
3. Populate: invoke the DeclareModules runtime function to populate each
_instance_ object with accessors for it exports. This is generated by
DeclareModules (invoked by VisitDeclarations in the hosting scope again),
and uses the descriptors generated in the previous stage.
4. Initialize: execute the module bodies (and other code) in sequence. This
happens by the separate statements generated for module bodies. To reenter
the module scopes properly, the parser inserted ModuleStatements.
R=mstarzinger@chromium.org,svenpanne@chromium.org
BUG=
Review URL: https://codereview.chromium.org/11093074
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13033 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
- The global object has a reference to the current global scope chain.
Running a script adds to the chain if it contains global lexical declarations.
- Scripts are executed relative to a global, not a native context.
- Harmony let and const bindings are allocated to the innermost global context;
var and function still live on the global object.
(Lexical bindings are not reflected on the global object at all,
but that will probably change later using accessors, as for modules.)
- Compilation of scripts now needs a (global) context (previously only eval did).
- The global scope chain represents one logical scope, so collision tests take
the chain into account.
R=svenpanne@chromium.org
BUG=
Review URL: https://chromiumcodereview.appspot.com/10872084
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12398 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The CompilationInfo record now saves a Zone, and the compiler pipeline
allocates memory from the Zone in the CompilationInfo. Before
compiling a function, we create a Zone on the stack and save a pointer
to that Zone to the CompilationInfo; which then gets picked up and
allocated from.
BUG=
TEST=
Review URL: https://chromiumcodereview.appspot.com/10534139
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11877 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
source code positions it gets from the program counter to recreate the scope
chain by reparsing the function or program.
This CL includes the following changes
* Adds source code positions for the assignment added by the rewriter.
* Run the preparser over global code first.
* Use the ScopeType from the ScopeInfo to determine if the code being debugged
is eval, function or global code instead of looking up the '.result' symbol.
TEST=mjsunit/debug-stepout-scope.js
Review URL: http://codereview.chromium.org/8590027
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10076 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Remove the try/finally used for with and catch. Instead of using
try/finally to handle break and continue from with or catch,
statically track nesting dept and clean up when compiling break or
continue.
And instead of using try/finally to handle throw to handler in a frame
whose pc is inside a with or catch, store the context that the handler
should run in in the handler itself.
BUG=
TEST=
Review URL: http://codereview.chromium.org/7618007
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8922 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The catch variable is bound in the catch scope. For simplicity in this
initial implementation, it is always allocated even if unused and always
allocated to a catch context even if it doesn't escape. The presence of
catch is no longer treated as a with.
In this change, care must be taken to distinguish between the scope where a
var declaration is hoisted to and the scope where the initialization occurs.
R=ager@chromium.org
BUG=
TEST=
Review URL: http://codereview.chromium.org/7280012
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8496 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Introduce separate maps for function and with contexts. Use the function
context map for testing whether a context is a function context (global
contexts are no longer function contexts).
Split the paths for allocating with and catch contexts.
Rename some functions. Generally refactor code to make it simpler.
R=ager@chromium.org
BUG=
TEST=
Review URL: http://codereview.chromium.org/7003058
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8231 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Change more functions used by the Compiler class to have a uniform
interface: they get passed as argument an input/output pointer to a
CompilationInfo that they mutate if they succeed, and they return a
flag telling whether they succeeded.
Also, remove some unnecessary timers.
Review URL: http://codereview.chromium.org/3561012
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5583 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
For some reason, the scope's arguments and arguments shadow were
variable proxies, which resulted in all references to the arguments
shadow being shared in the AST. This makes it hard to put per-node
state on the AST nodes.
I took the opportunity to remove Variable::AsVariable which has
confused people in the past, and to rename Variable::slot to the more
accurate Variable::AsSlot.
Review URL: http://codereview.chromium.org/3432022
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5517 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
