ITANIUM C ABI PDF

Discussion and development of the “Itanium” portable C++ ABI used by many major C++ implementations. – Itanium C++ ABI. The Itanium ABI (which GCC uses) may specify these things (as within specifying ranges) Most types’ size and alignment is specified in the Intel System V ABI. Virtual Table Layout General A virtual table (vtable) is a table of information used to dispatch virtual functions, to ac.

Each class has its own table that maps selectors to their implementations — the implementation pointer specifies where in memory the actual implementation of the method resides. The callee constructs the return value into this temporary. An instantiation of a function template or member function template is emitted in any object where its symbol is referenced non-inlinein a COMDAT group identified by the function name.

Free Pascal supports function and operator overloading, thus it also uses name mangling to support these features. Clarification in array cookie specification. Ooh, that is interesting. Otherwise, given the data address of an array, the non-negative size of prefix padding ahi the cookie, and the size of its elements, call the given destructor on each element, using the cookie to determine the number of elements, and then delete the space by calling:: Initialization itainum with the same priority from different files or from other sources such as link command options will be executed in an unspecified order.

Finally allocate any direct or indirect virtual base classes except the primary base class or any indirect primary base classes as we did non-virtual base classes in step II-2 if not empty or II-3 if emptyin inheritance graph order. Name mangling is also necessary in Fortran compilers, originally because the language is case insensitive.

Itanium C++ ABI

The types of two non-static member functions are considered to be different, for the purposes of substitution, if the functions are members of different classes. Here’s a helpful document: From Wikipedia, the free encyclopedia. The SEL value for a selector does not vary between classes. These tests are implemented by abi:: Note that nvsize C need not be a multiple of nvalign C.

Name mangling – Wikipedia

We will describe below the sequence of such items. Unless otherwise specified, preorder derived classes before their bases is intended. If a class has an implicitly-defined virtual destructor, its entries come after the declared virtual function pointers.

In Java, the signature of a method or a class contains its name and the types of its method arguments and return value where applicable. This adds the case: Update align C to max align Calign T. Note that this assumes that the same string literal occurring twice in a given function in fact represents a single entity, i.

For a virtual base, this is the offset in the virtual table of the virtual base offset for the virtual base referenced negative. This section specifies the contents of the f entry in the A-in-B virtual table. Both function types are, however, entered the substitution table; subsequent references to either variant of the function type will result in the use of substitutions. Add issue C-3 destructor API. Mangled names have the general structure: A function pointer a pointer to aabi function descriptor on Itanium.

Included bai reference in this ABI. Ambiguities are possible between extern “C” object names and type manglings, e. For a non-virtual base, this is the offset in the object of the base subobject.

c++ – To what extent does the Itanium ABI really specify padding and alignment? – Stack Overflow

Because of this, implementations of a method are given a specific identifier too — these are known as implementation pointers, and are given a type also, IMP. Email Required, but never shown. It will be called with the GP of the initialization entries. We describe the ordering from the entry itanuim to the virtual table address point to that furthest. Construction order between linked objects is determined by the initialization ordering specified in the base ABI.

This decision is independent of whether its components have been substituted, so an implementation may optimize by itaniun large structures for substitution before their components. The pragma applies to all file scope variables in the file where it appears, from the point of appearance to the next priority pragma or the end of the file.