Does *not* do a deep copy.
Semantically analyze Expression. Determine types, fold constants, etc.
Try to run semantic routines. If they fail, return NULL.
Print AST data structure in a nice format.
Combine e1 and e2 by CommaExp if both are not NULL.
If 'e' is a tree of commas, returns the leftmost expression by stripping off it from the tree. The remained part of the tree is returned via *pe0. Otherwise 'e' is directly returned and *pe0 is set to NULL.
Return !=0 if expression is an lvalue.
Give error if we're not an lvalue. If we can, convert expression to be an lvalue.
Resolve __FILE__, __LINE__, __MODULE__, __FUNCTION__, __PRETTY_FUNCTION__ to loc.
Check that the expression has a valid type. If not, generates an error "... has no type".
Check that the expression has a valid value. If not, generates an error "... has no value".
Calling function f. Check the purity, i.e. if we're in a pure function we can only call other pure functions. Returns true if error occurs.
Accessing variable v. Check for purity and safety violations. Returns true if error occurs.
Calling function f. Check the safety, i.e. if we're in a @safe function we can only call @safe or @trusted functions. Returns true if error occurs.
Calling function f. Check the @nogc-ness, i.e. if we're in a @nogc function we can only call other @nogc functions. Returns true if error occurs.
Check that the postblit is callable if t is an array of structs. Returns true if error happens.
Check whether the expression allows RMW operations, error with rmw operator diagnostic if not. ex is the RHS expression, or NULL if ++/-- is used (for diagnostics) Returns true if error occurs.
Parameters: sc: scope flag: 1: do not issue error message for invalid modification
If expression can be tested for true or false, returns the modified expression. Otherwise returns ErrorExp.
Destructors are attached to VarDeclarations. Hence, if expression returns a temp that needs a destructor, make sure and create a VarDeclaration for that temp.
Take address of expression.
If this is a reference, dereference it.
Does this expression statically evaluate to a boolean 'result' (true or false)?
Fake class which holds the thrown exception. Used for implementing exception handling.