information is in an unreachable block, then it's possible that the high/low pc
values won't be set for the dwarf information. E.g., this function:
void abort(void) __attribute__((__noreturn__));
void dead_beef(void) __attribute__ ((noreturn));
int *b;
void dead_beef(void) {
*b=0xdeadbeef;
abort();
}
has a call to "@llvm.dbg.region.end" only in the unreachable block:
define void @dead_beef() noreturn nounwind {
entry:
call void @llvm.dbg.func.start(...)
call void @llvm.dbg.stoppoint(...)
...
call void @abort( ) noreturn nounwind
unreachable
return: ; No predecessors!
call void @llvm.dbg.stoppoint(...)
call void @llvm.dbg.region.end(...)
ret void
}
The dwarf information emitted is something like:
0x00000084: TAG_subprogram [5]
AT_name( "dead_beef" )
AT_external( 0x01 )
AT_prototyped( 0x01 )
AT_decl_file( 0x01 )
AT_decl_line( 0x08 )
Note that this is *not* the best fix for this problem, but a band-aid for an
gaping wound. This code needs to be changed when we revamp our debugging
information.
llvm-svn: 56628
