[Bug corefiles/22795] Variables in the .bss section are printed as 32-bit

["simon.marchi at ericsson dot com" <sourceware-bugzilla at sourceware dot org>]

https://sourceware.org/bugzilla/show_bug.cgi?id=22795

--- Comment #3 from Simon Marchi <simon.marchi at ericsson dot com> ---
(In reply to Byron Hawkins from comment #2)
> If the type of the __environ variable is not known, then why does GDB assume
> type "int *" and dereference the pointer? I can suggest two reasonable
> options:
> 
> 1. print the address of __environ as a "void *" unless it knows the specific
> type of the variable. 
> 2. respond with an error "attempt to dereference a generic pointer", since
> the user did ask for the variable's value without providing a type. 
> 
> But casting the pointer to an arbitrarily chosen type is totally confusing.
> How can the user figure out that "char **__environ" has been cast to "int
> *"? There is nothing in the program to suggest that __environ should refer
> to any int anywhere, and there is nothing in the output to suggest that the
> printed value was truncated at 4 bytes (i.e., it is indistinguishable from
> an 8-byte type because leading zeros are omitted). 
> 
> If it is really necessary to presume a type, GDB should at the very least
> print what it is doing:
> 
>     Variable '__environ' has unknown type: assuming 'int *'

It used to assume the type, it doesn't anymore starting with GDB 8.1, for
exactly the reasons you mentioned.  So you just need to upgrade your GDB to
8.1.

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