Escape analysis

[Robert Jacques]

I've run across some academic work on ownership types which seems relevant  
to this discussion on share/local/scope/noscope.

Paper: http://www.cs.jhu.edu/~scott/pll/papers/pedigree-types.pdf
Slides: http://www.cs.jhu.edu/~scott/pll/papers/iwaco.ppt
Site: http://www.cs.jhu.edu/~scott/pll/abinitio.html
Overview:
Pedigree Types are an intuitive ownership type system requiring minimal  
programmer annotations. Reusing the vocabulary of human genealogy,  
Pedigree Types programmers can qualify any object reference with a  
pedigree -- a child, sibling, parent, grandparent, etc -- to indicate what  
relationship the object being referred to has with the referant on the  
standard ownership tree, following the owners-as-dominators convention.  
Such a qualifier serves as a heap shape constraint that must hold at run  
time and is enforced statically. Pedigree child captures the intention of  
encapsulation, i.e. ownership: the modified object reference is ensured  
not to escape the boundary of its parent. Among existing ownership type  
systems, Pedigree Types are closest to Universe Types. The former can be  
viewed as extending the latter with a more general form of pedigree  
modifiers, so that the relationship between any pair of objects on the  
aforementioned ownership tree can be named and -- more importantly --  
inferred. We use a constraint-based type system which is proved sound via  
subject reduction. Other technical originalities include a polymorphic  
treatment of pedigrees not explicitly specified by programmers, and use of  
linear diophantine equations in type constraints to enforce the hierarchy.