similar to: [LLVMdev] Is lld the linker we need for our project ?

Hi, Thanks a lot for your answer. It seems lld is still the best solution, even if it does not work "right out of the box" for us today. We already have a solution for the "objcopy" part (added the required output format to llvm-objdump). The ScriptLayout class seems to be empty for now (on the master branch at least), but we do not need linker scripts today. All that is

Hi, We are currently developing an LLVM target for a micro-controller, and would like our TargetLowering::LowerCall method to emit PUSH instructions (instead of STORE) to pass arguments (which would improve code density for function calls). Is there a way of keeping track of the stack pointer changes implied by the PUSH instruction to calculate the correct offsets in

Hi Rui, Shankar, Do we really need empty TargetLayout class? No we have the following hierarchy: Layout <- DefaultLayout<> <- TargetLayout<> <- xxxTargetLayout<> I suggest to remove TargetLayout and rename DefaultLayout to TargetLayout. Thoughts? -- Simon Atanasyan

Good point. But I suggest to do that by two steps. First, remove TargetLayout and rename DefaultLayout to TargetLayout. Second, merge TargetLayout and Layout. The first step is easy, the second step generates large diff, requires reviewing etc. On Fri, Apr 3, 2015 at 10:40 PM, Rui Ueyama <ruiu at google.com> wrote: > I'm wondering if we even need TargetLayout. > > DefaultLayout

Debug info linking is currently broken due to how we handle reading and laying out non SHF_ALLOC sections. I posted a patch that partially fixes this, but it's both the wrong approach and doesn't handle multiple input files with debug info (wrong relocation values). The first issue is representing non SHF_ALLOC atoms in the Atom model. We currently don't have a type for this, and

Hi, Now lld writes relocations to the ".rela" sections only. Mips requires to use the "rel" format. So we need to be able to select format and names of relocation section, names of symbols like __rela_iplt_* / __rel_iplt_*, dynamic table tag DT_RELA / DT_REL. My current idea: - Add two virtual functions DefaultLayout::createDynamicRelocationTable() and

Hi Michael, On 9/16/2013 7:23 PM, Michael Spencer wrote: > Debug info linking is currently broken due to how we handle reading and > laying out non SHF_ALLOC sections. I posted a patch that partially fixes > this, but it's both the wrong approach and doesn't handle multiple input > files with debug info (wrong relocation values). > > The first issue is representing non

On Mon, Sep 16, 2013 at 6:48 PM, Shankar Easwaran <shankare at codeaurora.org>wrote: > Hi Michael, > > > On 9/16/2013 7:23 PM, Michael Spencer wrote: > >> Debug info linking is currently broken due to how we handle reading and >> laying out non SHF_ALLOC sections. I posted a patch that partially fixes >> this, but it's both the wrong approach and

Hi, Right now, linker added symbols specified by the -u option do not endup in the output YAML file. This is because the target specific Writers dont get called, which creates the undefined atoms. I am in the process of adding more options and I would like the atoms created internally by the options available in the output YAML file. The options that I am trying to consider for the linker

On Mon, Apr 20, 2015 at 1:44 AM, Shankar Easwaran <shankarke at gmail.com> wrote: > Attached patch fixes the issue. Thanks for the quick fix. The patch LGTM if you add a test case. Unfortunately yaml2obj does not support duplicated section names but we can use a binary input file. -- Simon Atanasyan

Shankar, The LinkingContext has a addImplictFiles() method that is supposed to call the Writer and give it a chance to add any implicit files. Is the problem that the -u atoms are not attached to that implicit file? Or that the implicit file is not getting added? Or that this got lost in the transition from InputFiles to InputGraph? -Nick On Aug 28, 2013, at 2:44 PM, Shankar Easwaran

On Wed, Jan 2, 2013 at 12:04 PM, Shankar Easwaran <shankare at codeaurora.org> wrote: > You might want to look at the ELFLayout changes to see what functionality is > missing from that. > > The ELFLayoutOptions has a hook into reading the Linker script which needs > to be implemented. So, looking into it a bit, I think that ELFLayoutOptions is not the right place to parse the

Nothing wrong with going ahead with a temporary measure if the temporary measure is reasonable (besides the discussion if checking in binary files is desirable). Even if you plan to add a test written in YAML, it's better to check in a binary at least for now than checking it in without any tests. On Mon, Apr 20, 2015 at 7:59 AM, Shankar Easwaram <shankarke at gmail.com> wrote: > I

On Mon, Jan 7, 2013 at 9:44 AM, Shankar Easwaran <shankare at codeaurora.org> wrote: > Also the linker script functionality is only needed by ELF and not anything > else. It should be contained only within ELF. I agree with your point about encapsulation and separation of concerns. However, I believe that GNU ld will accept and use linker scripts even for the non-ELF formats it

Hi Sean, The hook to add symbols into the Reader is through Writer->addFiles function. I think still the linker script should be parsed by Writer. Also the linker script functionality is only needed by ELF and not anything else. It should be contained only within ELF. Thanks Shankar Easwaran On 1/6/2013 2:05 PM, Sean Silva wrote: > On Wed, Jan 2, 2013 at 12:04 PM, Shankar Easwaran

Hi Nick, The problem is when the -emit-yaml option is used, the writer is set to the YAML writer. The YAML writer doesnot have anything to add here. The problem can be solved by having the YAML writer append a list of undefined atoms specified by the -u option, but the problem I have is each flavor has extra command line options for which it wants to create a DefinedAtom/UndefinedAtom. The

Hi Sean, Thanks for providing us the information on the linker scripts. Linker scripts also use a wide variety of keywords like :- 1) SORT 2) ALIGN 3) OVERLAY Overlays are most commonly used in embedded applications to overlay one section over the other using a custom overlay manager. You might want to look at the ELFLayout changes to see what functionality is missing from that. The

Hi All, I have a design question of how your linker would be suitable for modeling ELF semantics. The ELF linker needs the functionality of reading relocations ahead of symbol resolution for the following usecases :- - Add linker defined symbols if there is a relocation to the symbol (Examples are : defsym, PROVIDE) - Dont halt the linker operation if there are undefined symbols but they are

Hi Nick, >> The YAML writer does not have anything to add here. >> >> The problem can be solved by having the YAML writer append a list of undefined atoms specified by the -u option, but the problem I have is each flavor has extra command line options >> for which it wants to create a DefinedAtom/UndefinedAtom. The flavor also may want to add extra linker internal files in

Hi Nick, On 8/28/2013 6:37 PM, Nick Kledzik wrote > $cat 1.c > int _start() { return 0; } > $gcc -c 1.c > $ld -u myundef 1.o > ==> Does not throw any error, the resolver was hinted that myundef was a undefined weak symbol. > Wow. Reading the gnu ld man page, that is not obvious. How can you make a non-weak undefined on the command line? That is, how can you force and error