pmachata/reader_hooks review

[Roland McGrath <roland at redhat dot com>]

Defns have to do:
	int
	internal_function
	foo (...)
i386 build will break with internal_function decls but not defns.

s/dwarf_readhooks.c/libdw_relocate.c/
A dwarf_*.c name is for a file implementing a function of that name.

All the calls seem to use a size == 8 expression for the bool argument.
Just make it an offset/address size argument that is 4/8.

s/addr/off/ in dwarf_formref_die, dwarf_getpubnames

+      Dwarf_Addr escape = addr64 ? (Elf64_Addr)-1 : (Elf64_Addr)(Elf32_Addr)-1;
Write a libdwP.h macro for this (taking address_size rather than bool).
It will be used again in dwarf_ranges.

s/Dwarf_Word/Dwarf_Off/ for offset-flavored parameters.
s/Dwarf_Word/Dwarf_Addr/ for address-flavored parameters.

I don't think the names are too long.  Let's use "address" and "offset".
If it makes the decoder code nicer, define macros or static inlines
"read_address" and "read_offset" (+"_inc") wrappers for convenience.
(You might want to do that for the _inc flavors anyway, so the arithmetic
inlines away.) 

Make read_offset also take an IDX_* argument for the referring section.
If it's a macro, you can make the args short and use IDX_debug_##arg.

+  if (*offset >= data->d_size
+      || *offset + addr64 ? 8 : 4 >= data->d_size)
Use:
       || data->d_size - offset_size < *offset)

Don't call the addr function in the off function.  Even as soon as the test
code, they will be disjoint code paths.  (A common local inline that has
the size-check if clause and zero extension is fine of course.)

Use const pointers everywhere.

Two of these:
+	    return -1l;
Neither of those functions return long int.  Use plain -1.


Thanks,
Roland