What kinds of programming pitfalls modern languages are able to find? I often see claims that modern functional strictly-typed languages are 'safer' than others. These statement mostly linked with type systems and their ability to explicitly express the following pitfalls:

Alternatives in function result. Maybe and Either datatypes vs. exceptions and null-pointers in C++-like languages.
Access to mutable state (possibly inconsistent behavior over time). State datatype in Haskell vs. variables in C++-like languages.
Performing IO. IO datatype in Haskell vs. just doing things in C++-like languages.

Haskell allows to express constraints required for safe handling of these situations. And compiler is able to warn programmer when he doesn't follow them.
Although pitfalls above are definitely the most common ones I can think of much more, for example:

Unexpected resource consumption. Memory, CPU, disk, bandwidth.
Inconsistent access to shared resources. Like read and write interference, broken lock ordering.
System-level failure. Like crashing process or pulled plugs.
Unexpected execution time for IO, timing violation.

Is there languages, libraries or at least models which allow to express constraints from the second set and yield a warning when they are not met?
Substructural types ( http://en.wikipedia.org/wiki/Substructural_type_system ) can be used to provide some version of each of those. As a summary, while normal types control how something may be used, substructural types further control when or how often it may be used.


Affine types can be used to construct languages capable of expressing all, and only, polynomial-time functions. http://www.cs.cmu.edu/~fp/courses/15816-s12/misc/aehlig02tocl.pdf
Linear types can enforce that memory is accessible when variables go out of scope, enabling a kind of "static garbage collection." Similarly, ordered types can be used to require that variables are used in a LIFO order, allowing them to be stack-allocated. Regions ( http://en.wikipedia.org/wiki/Region-based_memory_management ) are also useful here. The first chapter of Advanced Topics in Types and Programming Languages provides a nice introduction to using linear and ordered types for this purpose.
Affine types also enable typestate-oriented programming ( http://www.cs.cmu.edu/~aldrich/papers/onward2009-state.pdf ). Typestate is used to enforce certain orderings in APIs (e.g.: can't read from a closed file), but can also be used to enforce safety properties. Requiring a block that handles some error can be encoded as requiring a function that transitions some object from an error state to a recovery state.