Help: 'unresolved expression that must be resolved'

Help: 'unresolved expression that must be resolved'

[Michael Chapman]

I have trouble trying to refer to a label in the assembler 
anywhere.

The one line test program

	subroutine: call subroutine

gives me

$ gas test1.asm
test1.asm: Assembler messages:
test1.asm:1: Error: unresolved expression that must be resolved
$ 

What does it mean that an expression is unresolved?

Here below is the relevant parts from my .cpu file.

Any explanations as to how to make this simple example work
would be most welcome.

Thanks.
Mike Chapman


; Opcode fields
(dnf f-call-opcode "call opcode" () 7 6)

; Absolute address, 26-bit (shifted 1 bit to right)
(df f-abs26   "abs26"  (ABS-ADDR) 
    31 26 UINT
    ((value pc) (sra WI value (const 1)))
    ((value pc) (sll WI value (const 1))))

; Instruction operands.
(dnop abs26  "abs26"         ()       h-iaddr f-abs26)

; Instructions
(dni call-abs26 "call abs26"
     (UNCOND-CTI)
     "call $abs26"
     (+ (f-call-opcode #xf3) abs26)
     (set pc abs26)
     ()
)

Re: Help: 'unresolved expression that must be resolved'

[Frank Ch. Eigler]

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Hi -

On Mon, Sep 30, 2002 at 04:21:59PM +0200, Michael Chapman wrote:
> [...]
> The one line test program
> 
> 	subroutine: call subroutine
> 
> gives me
> 
> $ gas test1.asm
> test1.asm: Assembler messages:
> test1.asm:1: Error: unresolved expression that must be resolved
> $ 
> What does it mean that an expression is unresolved?

It means that the assembler can neither emit a literal value for
the expression (the address of the "subroutine" symbol), nor does
it have an available relocation type so that the linker can fill
in a value.  If the operand was declared as PC-relative (see
PCREL-ADDR), the assembler would be able to resolve the value at
assembly time (probably -2 or something like that).


- FChE

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RE: Help: 'unresolved expression that must be resolved'

[Michael Chapman]

Hi again,

So how do I get a relocation type in their?
Mike


-----Original Message-----
From: Frank Ch. Eigler [mailto:fche@redhat.com]
Sent: Monday, 30 September, 2002 16:27
To: Michael Chapman
Cc: cgen@sources.redhat.com
Subject: Re: Help: 'unresolved expression that must be resolved'


Hi -

On Mon, Sep 30, 2002 at 04:21:59PM +0200, Michael Chapman wrote:
> [...]
> The one line test program
> 
> 	subroutine: call subroutine
> 
> gives me
> 
> $ gas test1.asm
> test1.asm: Assembler messages:
> test1.asm:1: Error: unresolved expression that must be resolved
> $ 
> What does it mean that an expression is unresolved?

It means that the assembler can neither emit a literal value for
the expression (the address of the "subroutine" symbol), nor does
it have an available relocation type so that the linker can fill
in a value.  If the operand was declared as PC-relative (see
PCREL-ADDR), the assembler would be able to resolve the value at
assembly time (probably -2 or something like that).


- FChE

Re: Help: 'unresolved expression that must be resolved'

[Frank Ch. Eigler]

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Hi -

On Mon, Sep 30, 2002 at 04:54:03PM +0200, Michael Chapman wrote:
> So how do I get a relocation type in their?

You need to do some gas/bfd hacking outside cgen's purview.
See gas/config/tc-TARGET, bfd/elf*-TARGET, include/elf/TARGET*,
etc.  All hand-made, I'm afraid.


- FChE

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RE: Help: 'unresolved expression that must be resolved'

[Michael Chapman]

Hi,

Thanks. It was the gas/config/tc-TARGET I had forgotten all 
about. I see kind of how that adds up now.

Lets see if I can make that work.

Thanks for your help.

Mike


-----Original Message-----
From: Frank Ch. Eigler [mailto:fche@redhat.com]
Sent: Monday, 30 September, 2002 17:04
To: Michael Chapman
Cc: cgen@sources.redhat.com
Subject: Re: Help: 'unresolved expression that must be resolved'


Hi -

On Mon, Sep 30, 2002 at 04:54:03PM +0200, Michael Chapman wrote:
> So how do I get a relocation type in their?

You need to do some gas/bfd hacking outside cgen's purview.
See gas/config/tc-TARGET, bfd/elf*-TARGET, include/elf/TARGET*,
etc.  All hand-made, I'm afraid.


- FChE