[RFA] stabs: remember types that cross reference another type

Daniel Jacobowitz drow@mvista.com
Mon Nov 3 18:16:00 GMT 2003


On Fri, Oct 31, 2003 at 12:08:51PM -0800, Joel Brobecker wrote:
> Hello,
> 
> We encountered the following problem when using GNAT to compile
> the following pasted at the end of this message. Sorry the program
> is in Ada instead of C, but I couldn't reproduce it with C.
> 
> The problem is when the user tries to print the type of My_Str.
> GDB should return a string, but instead we got:
> 
>         Attempt to take contents of a non-pointer value
> 
> After investigating, I found that the stabs generated by the compiler
> contained the following entries:
> 
>         .stabs "s5:(0,97)=xsstring___XUP:",128,0,5,-476
>         .stabs "R6b:(0,97)",128,0,12,-484
> 
> (R6b is a variable that GDB ends up using in place of My_Str for reasons
> that are related to the encoding used by GNAT).
> 
> So when GDB reads the type information for R6b, it finds that it is
> of type number (0,97), which should mean the same type as s5.
> Unfortunately, GDB forgot to save a reference to the type associated
> to type (0,97) in the type_vector when processing the type of variable
> named "s5". So later on, when GDB tries to compute the type of "R6b",
> it doesn't find type (0,97) and therefore assumes it will be defined
> later, and hence creates a empty type object which it hopes will be 
> filled in later.
> 
> As a consequence, when the ada mode tries to print the type of R6b,
> it trips over the unexpected symbol type code, and bails out with
> the error message above.
> 
> The attached patch fixes this particular case.
> 
> 2003-10-31  J. Brobecker  <brobecker@gnat.com>
> 
>         * stabsread.c (read_type): Save a reference to types that are defined
>         as cross references to other types.
> 
> Tested on x86-linux, no regression.
> 
> Ok to apply?

No patch?

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer



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