[named address] rejects-valid: error: initializer element is not computable at load time

[Ulrich Weigand]

Georg-Johann Lay wrote:

> For the following 1-liner I get an error with current trunk r177267:
> 
> const __pgm char * pallo = "pallo";
> 
> __pgm as a named address space qualifier.
[snip]
> Moreover, if a user writes a line like
>    const __pgm char * pallo = "pallo";
> he wants the string literal to be placed in the non-default address
> space.  There is no other way to express that except something like
>    const __pgm char * pallo = (const __pgm char*) "pallo";
> which doesn't work either and triggers
> 
> pgm.c:1:1: error: initializer element is not constant
> 
> with a tree dump similar to above.

This is pretty much working as expected.  "pallo" is a string literal
which (always) resides in the default address space.  According to the
named address space specification (TR 18037) there are no string literals
in non-default address spaces ...

The assignment above would therefore need to convert a pointer to the
string literal in the default space to a pointer to the __pgm address
space.  This might be impossible (depending on whether __pgm encloses
the generic space), and even if it is possible, it is not guaranteed
that the conversion can be done as a constant expression at compile time.

What I'd do to get a string placed into the __pgm space is to explicitly
initialize an *array* in __pgm space, e.g. like so:

const __pgm char pallo[] = "pallo";

This is defined to work according to TR 18037, and it does actually
work for me on spu-elf.

Bye,
Ulrich

-- 
  Dr. Ulrich Weigand
  GNU Toolchain for Linux on System z and Cell BE
  Ulrich.Weigand@de.ibm.com