[vta] handle references to const strings in debug info

[Alexandre Oliva]

If the value of debug variables can be computed by dereferencing
portions of constant strings, not output in non-debug sections,
arrange for the string to be emitted in the .debug_str section, and
set the location of the variable to refer to it.

It would be nicer to just resolve the indirection to a value, but
there's no way (yet) to encode debug information for this case.

Meanwhile, I'm going ahead and installing this in the branch.

-------------- next part --------------
A non-text attachment was scrubbed...
Name: vta-dwarf2out-indirect-const-string.patch
Type: text/x-patch
Size: 5647 bytes
Desc: not available
URL: <http://gcc.gnu.org/pipermail/gcc-patches/attachments/20081121/93b2d181/attachment.bin>
-------------- next part --------------

-- 
Alexandre Oliva           http://www.lsd.ic.unicamp.br/~oliva/
You must be the change you wish to see in the world. -- Gandhi
Be Free! -- http://FSFLA.org/   FSF Latin America board member
Free Software Evangelist      Red Hat Brazil Compiler Engineer