[LLVMdev] LLD improvement plan

[Will Newton]

On Wed, May 6, 2015 at 6:22 AM, Chris Lattner <clattner at apple.com> wrote:
> On May 5, 2015, at 6:47 PM, Daniel Dilts <diltsman at gmail.com> wrote:
>
> Take a look at how debuggers have migrated through the years.  They too
>>
>> used to have their own script format.  Now most (all?) popular debuggers
>> do scripting through embedding an actual programming language.  This
>> could be a better way forward for linkers as well -- embed Python in the
>> linker, define a Python API for linkable item placement, entry point,
>> symbol operations, etc..., and then you also have the rest of Python at
>> your fingertips.
>
>
> I mostly care about specifying address where specific symbols will be placed
> and specifying the memory layout of the platform.   I normally use
> __attribute__((section(""))) to place the symbols in their own sections and
> then use the linker script to place the sections at the required addresses.
> How would this be accomplished without linker scripts?
>
>
> I’d prefer to use an "__attribute__((address(0x1234)))” myself.  That way
> you can control platform specifics with #ifdefs.

But that way you have to do layout by hand in C. Generally you won't
know the size of the preceding code or data so you won't know what
address to put things at at the granularity of a single C level
object/function. Better to say "put this in the ROM section" and set
the address of the ROM section once in a linker script and let the
linker do the layout.