Impl Generic Function

Generic Type/Function

Generic Types and Functions are implemented with the idea to keep type information to bind restrictions to void* usage.

Type Variable Declaration Implementation

Type variables are declared inside _For_any() function specifier. As such, type variables are parsed during function specifier parsing phase.

Type variables are constructed as a typedef, for its similiarity to typedef. It also gives an advantage in implementation perspective as clang already completely implemented typedef, including making sure that a newly created typedef name is not present in the scope.

_For_any Scope

There are two issues that we must be careful with creating a scope for _For_any specifier. First, _For_any scope must begin from the function declaration (including return type) and end at semicolon (for simple declaration) or end at the end of function body (for declaration with function body). Second, the function name itself must be registered outside of _For_any scope. Otherwise, when we go out of _For_any scope, the function no longer exists. The function name must be registered after parsing function qualifiers/ specifiers in order to collect enough information about the function. Also, the function name must be registered before the function body in case the function is used as a recursive function. This means that the function name must be registered to the parent "declaration" scope of _For_any scope, while the _For_any scope is the current scope.

For the first issue, there are two exit points in Parser::ParseDeclGroup in ParseDecl.cpp where the code decides that they are done parsing function declarations (without, and with function body). In both cases, we make sure that the current scope we are in is created from _For_any specifier, and exit scope.

For the second issue, there are also two places where clang registers function names. Clang registers function declaration without function body in ParseDeclarationAfterDeclaratorAndAttributes in ParseDecl.cpp. Clang registers function declaration with function body in ParseFunctionDefinition in Parser.cpp In both cases, if the function has _For_any specifier, we register the function on the parent scope, since the current scope is _For_any scope.