Differential D15709 Diff 44961 cfe/trunk/include/clang/Basic/AttrDocs.td

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cfe/trunk/include/clang/Basic/AttrDocs.td

Show First 20 Lines • Show All 1,853 Lines • ▼ Show 20 Lines	.. code-block: c++
public:		public:
int foo1() override {		int foo1() override {
return callee(); // This call is tail-call optimized.		return callee(); // This call is tail-call optimized.
}		}
};		};

}];		}];
}		}

		def AnyX86InterruptDocs : Documentation {
		let Category = DocCatFunction;
		let Content = [{
		Clang supports the GNU style ``__attribute__((interrupt))`` attribute on
		x86/x86-64 targets.The compiler generates function entry and exit sequences
		suitable for use in an interrupt handler when this attribute is present.
		The 'IRET' instruction, instead of the 'RET' instruction, is used to return
		from interrupt or exception handlers. All registers, except for the EFLAGS
		register which is restored by the 'IRET' instruction, are preserved by the
		compiler.

		Any interruptible-without-stack-switch code must be compiled with
		-mno-red-zone since interrupt handlers can and will, because of the
		hardware design, touch the red zone.

		1. interrupt handler must be declared with a mandatory pointer argument:

		.. code-block:: c

		struct interrupt_frame
		{
		uword_t ip;
		uword_t cs;
		uword_t flags;
		uword_t sp;
		uword_t ss;
		};

		__attribute__ ((interrupt))
		void f (struct interrupt_frame *frame) {
		...
		}

		2. exception handler:

		The exception handler is very similar to the interrupt handler with
		a different mandatory function signature:

		.. code-block:: c

		__attribute__ ((interrupt))
		void f (struct interrupt_frame *frame, uword_t error_code) {
		...
		}

		and compiler pops 'ERROR_CODE' off stack before the 'IRET' instruction.

		The exception handler should only be used for exceptions which push an
		error code and all other exceptions must use the interrupt handler.
		The system will crash if the wrong handler is used.
		}];
		}