llvm-project/llvm/test/Assembler/2007-09-10-AliasFwdRef.ll

; RUN: llvm-as < %s | llvm-dis
; PR1645

@__gthread_active_ptr.5335 = internal constant i8* bitcast (i32 (i32)* @__gthrw_pthread_cancel to i8*)    
@__gthrw_pthread_cancel = alias weak i32 (i32)* @pthread_cancel   


define weak i32 @pthread_cancel(i32) {
  ret i32 0
}
Fix PR1645 by resolving forward alias references. llvm-svn: 41815 2007-09-11 07:23:53 +08:00			`; RUN: llvm-as < %s \| llvm-dis`
			`; PR1645`

			`@__gthread_active_ptr.5335 = internal constant i8* bitcast (i32 (i32)* @__gthrw_pthread_cancel to i8*)`
			`@__gthrw_pthread_cancel = alias weak i32 (i32)* @pthread_cancel`



Reject alias to undefined symbols in the verifier. On ELF and COFF an alias is just another name for a position in the file. There is no way to refer to a position in another file, so an alias to undefined is meaningless. MachO currently doesn't support aliases. The spec has a N_INDR, which when implemented will have a different set of restrictions. Adding support for it shouldn't be harder than any other IR extension. For now, having the IR represent what is actually possible with current tools makes it easier to fix the design of GlobalAlias. llvm-svn: 203705 2014-03-13 04:15:49 +08:00			`define weak i32 @pthread_cancel(i32) {`
			`ret i32 0`
			`}`