similar to: [LLVMdev] [lld] supporting gnu linkonce sections in core linking

Hi Nick, I am trying to implement support for handling section groups in lld. There are two ways of figuring out section groups with ELF. a) Sections with SHF_GROUP property b) .gnu.linkonce sections (the signature identified by the name of the section) -- This was the method to coalesce similiar constants. Section Groups(SHF_GROUP) is the preferred way on ELF but .gnu.linkonce sections is

On Oct 29, 2013, at 9:52 PM, Shankar Easwaran wrote: > I am trying to implement support for handling section groups in lld. > > There are two ways of figuring out section groups with ELF. > > a) Sections with SHF_GROUP property > b) .gnu.linkonce sections (the signature identified by the name of the section) -- This was the method to coalesce similiar constants. > >

On 10/30/2013 12:53 AM, Nick Kledzik wrote: > On Oct 29, 2013, at 9:52 PM, Shankar Easwaran wrote: >> I am trying to implement support for handling section groups in lld. >> >> There are two ways of figuring out section groups with ELF. >> >> a) Sections with SHF_GROUP property >> b) .gnu.linkonce sections (the signature identified by the name of the section)

Hi Nick, Bigcheese, When lld is used to link C++ code, it would be required to demangle symbol names by default/user driven option. The Gnu linker has the following options :- --demangle=[style] --no-demangle I found that clang/llvm-symbolizer use __cxx_demangle function. I would think that lld also need to call the same function, and I think the way we want to demangle is to have 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

On 10/7/2013 3:23 PM, Nick Kledzik wrote: > On Oct 4, 2013, at 8:50 PM, Shankar Easwaran <shankare at codeaurora.org> wrote: >> It is needed that lld verifies the input to the linker. >> >> For example : a x86 ELF file can be given to lld when the target is x86_64. Similiarly with other flavors. >> >> I was thinking to have a varargs function in the

On 4/2/2014 12:23 PM, Nick Kledzik wrote: > On Apr 1, 2014, at 9:19 PM, Shankar Easwaran wrote: > >> Hi Nick, Bigcheese, >> >> When lld is used to link C++ code, it would be required to demangle symbol names by default/user driven option. >> >> The Gnu linker has the following options :- >> >> --demangle=[style] >> --no-demangle >>

Could you elaborate a bit about the issue that you are trying to solve with this suggestion? On Tue, Apr 1, 2014 at 9:27 PM, Shankar Easwaran <shankare at codeaurora.org>wrote: > Hi Nick, Bigcheese, > > Resurrecting a old thread. > > Now since we have a Registry that models Readers, do we want to have a > function in the Registry that evaluates whether a file should be

On 9/24/2013 2:33 PM, Rui Ueyama wrote: > Hi LLD developers, > > I'm about to make a change to invert the return value of > Driver::parse() to return true on success. Currently it returns false > on success. You have to be a bit careful here, as the return from parse is used as a exit code from lld. The Unix shell interprets 0 (false as success) as 1(true as failure). It

> There are also odd stuffs such as COMDAT groups or > merge-not-by-name-but-by-content sections, that may complicate the model. (I > don't think about that yet.) For comdats (on ELF) you should be able to avoid even reading the bits from subsequent files once a comdat of a given name has been found. Cheers, Rafael

Hi LLD developers, I'm about to make a change to invert the return value of Driver::parse() to return true on success. Currently it returns false on success. In many other functions, we return true to indicate success and false to indicate failure. The inconsistency is confusing, and fixing it should improve code readability. -------------- next part -------------- An HTML attachment was

On Jul 29, 2013, at 10:09 AM, Shankar Easwaran wrote: > On 7/29/2013 11:24 AM, Nick Kledzik wrote: >> On Jul 25, 2013, at 2:10 PM, Rui Ueyama wrote: >>> Is there any reason -ffunction-sections and -fdata-sections wouldn't work? If it'll work, it may be be better to say "if you want to get a better linker output use these options", rather than defining new ELF

... > Thanks, applied in r103150! llvm-mc -filetype=obj probably needs a similar > patch. > > cool!, I will make that change and submit it too. > ... > Yes probably, I don't know what the .def and .scl directives "do" :) > > I think I can figure out the right thing to do here. > Also, w.r.t. section handling stuff, there is this fixme in the asmprinter:

On 7/30/2013 5:43 PM, Nick Kledzik wrote: > On Jul 29, 2013, at 10:09 AM, Shankar Easwaran wrote: > >> On 7/29/2013 11:24 AM, Nick Kledzik wrote: >>> On Jul 25, 2013, at 2:10 PM, Rui Ueyama wrote: >>>> Is there any reason -ffunction-sections and -fdata-sections wouldn't work? If it'll work, it may be be better to say "if you want to get a better linker

Hi Dan, lld takes a -emit-yaml option, which emits the intermediate representation(atoms) in YAML form. By default output goes to stdout, the user can control it by using the -o option too. The way its handled is, similiar to this piece of pseudo-code if (dash_o_option) outputFile = dash_o_option->value() else outputFile = "-" When lld tries to mix things that go to

On Mon, May 11, 2015 at 11:13 AM, Rui Ueyama <ruiu at google.com> wrote: > If you attach two ore more symbols along with offsets to a chunk of data, > it would be a pretty similar to a section. That means that if you want to > do something on the atom model, now you have to treat the atoms like > sections. > What do you lose/pay by having to treat the atoms like sections?

Hi Dan, The other messages, need to go to stdout as well. Using stderr to output for a switch like --verbose is wrong in my opinion. On 8/14/2013 4:44 PM, Dan Gohman wrote: > Would it be appropriate for lld's other output to go to standard error > instead of standard output, since standard output may be used for YAML > output? > > Dan > > On Wed, Aug 14, 2013 at 12:53

Not all users compile their code with -ffunction-sections and -fdata-sections. This is to handle usecases when libraries use a mix of object files too. On 7/25/2013 4:10 PM, Rui Ueyama wrote: > Is there any reason -ffunction-sections and -fdata-sections wouldn't work? > If it'll work, it may be be better to say "if you want to get a better > linker output use these

# is a line comment chracter in YAML so it's valid. That's why I wrote a simple magic "comment". On Thu, Oct 10, 2013 at 6:21 PM, Shankar Easwaran <shankare at codeaurora.org>wrote: > On 10/10/2013 5:00 PM, Rui Ueyama wrote: > >> On Thu, Oct 10, 2013 at 9:16 AM, Shankar Easwaran >> <shankare at codeaurora.org>**wrote: >> >> On

http://llvm.org/docs/LangRef.html#linkage-types says: Globals with “linkonce” linkage are merged with other globals of the same name when linkage occurs. This can be used to implement some forms of inline functions, templates, or other code which must be generated in each translation unit that uses it, but where the body may be overridden with a more definitive definition later. Unreferenced