similar to: [LLVMdev] Getting The Resulting Size of Appending Linkage Array?

Can anyone explain how llc translates "appending linkage" global variables like llvm.global_ctors into assembly? In the case I am examining, the global_ctor variables are in multiple bitcode object modules produced by the llvm compiler as arrays of pointers. As documented, the arrays seem to be combined when the different bitcode object modules are linked into one, so now there is one

Sorry if this question is a repeat, I never got an answer the last time I asked :) How does appending linkage interact with dead global elimination? From what I understand, appending linkage arrays are stitched together by the linker. Dead global elimination usually happens after linking, so if any of those arrays are "live", then any globals that they point to will be live as well. My

Talin wrote: > I'm trying to figure out how to do static initialization (like static > constructors in C++ or Java). I figured I would use appending linkage - > that is, for each module I'd generate a function that did all of the > static initialization for that module, and then I'd put a pointer to > that function in an array with appending linkage. Then my >

I'm trying to figure out how to do static initialization (like static constructors in C++ or Java). I figured I would use appending linkage - that is, for each module I'd generate a function that did all of the static initialization for that module, and then I'd put a pointer to that function in an array with appending linkage. Then my compiler-generated startup code would simply

My apologies for opening up an old thread, but I've been thinking about this quite a bit lately, and it seems to me that "appending linkage" would be a lot more useful in general if there was some way to determine the size of the appended array without having to write a custom pass to do it. In other words, using the standard llvm tools (llvm-link and friends), one ought to be

This is an issue I raised a while ago, but I wanted to know if the situation had improved at all recently. The issue is determining the number of elements in an array that has appending linkage. The obvious course would be to use a constant GEP. Suppose we have N modules, each containing a global variable with appending linkage whose initializer is an array of size M containing elements of type

On Thu, Dec 10, 2009 at 12:26 AM, Robin Sommer <robinsommer at web.de> wrote: > > On Sat, Dec 05, 2009 at 22:56 -0800, I wrote: > >> the LLVM documentation lists the 'appending' linkage for having the >> linker combine two arrays. I'm wondering though if it's then >> possible to get the size of the combined array, e.g., for iterating >> over

On Thu, Dec 10, 2009 at 2:05 AM, Eli Friedman <eli.friedman at gmail.com> wrote: > On Thu, Dec 10, 2009 at 12:26 AM, Robin Sommer <robinsommer at web.de> wrote: >> >> On Sat, Dec 05, 2009 at 22:56 -0800, I wrote: >> >>> the LLVM documentation lists the 'appending' linkage for having the >>> linker combine two arrays. I'm wondering

John Criswell wrote: > Talin wrote: > >> I'm trying to figure out how to do static initialization (like static >> constructors in C++ or Java). I figured I would use appending linkage - >> that is, for each module I'd generate a function that did all of the >> static initialization for that module, and then I'd put a pointer to >> that function in

On Tue, Feb 18, 2020 at 9:42 PM David Blaikie <dblaikie at gmail.com> wrote: > I'm /guessing/ this might be related to the COFF support specifically > (perhaps COFF has no appending linkage support - in some cases LLVM IR > supports the union of all semantics so that different formats can be fully > expressed - but it means when targeting certain formats, some features are

Hi all, the LLVM documentation lists the 'appending' linkage for having the linker combine two arrays. I'm wondering though if it's then possible to get the size of the combined array, e.g., for iterating over its elements? Or how would I otherwise use the combined array? Thanks, Robin -- Robin Sommer * Phone +1 (510) 666-2886 * robin at icir.org ICSI/LBNL * Fax +1

Hello. I'm posting this question here, because there seem to be no LLD-specific mailing list. Sorry in advance if this is wrong one. I compile two C source with following command: clang -flto -o %name.bc %name.c LLVM is augmented with my custom pass, which amongst other things create a global with appending linkage: @myvar = appending constant [1 x [1 x i8]*] ... I also have another pass

> That's essentially what I did to get it to work but instead of > appending, I just opted for LinkOnce. Sounds ok. > > I don't quite understand why you need an appending global to do this, if you > > can only have one main. I would just set it to the correct initializer in the > > module that has main, and leave it external everywhere else. > > Its

On Sat, Dec 05, 2009 at 22:56 -0800, I wrote: > the LLVM documentation lists the 'appending' linkage for having the > linker combine two arrays. I'm wondering though if it's then > possible to get the size of the combined array, e.g., for iterating > over its elements? Or how would I otherwise use the combined array? Any thoughts on this? Am I missing something?

Append linkage is magical. It doesn't correspond to anything available in real object files (ELF/COFF/MachO). In those files sections are appended, but symbols are just resolved. That means that appending linkage can only be used with llvm special symbols that never hit a real .o. Long term I think we should delete it an replace with explicit use of section. But for now I would like to just

On Mon, 17 Nov 2003, Reid Spencer wrote: > On Mon, 2003-11-17 at 22:44, Chris Lattner wrote: > > > We already have never, ever, delete this flags. "weak" and external > > linkage both guarantee that. If there can be an external caller of some > > function, for example, the optimizer CANNOT delete it, nor can it change > > it's interface. > >

Robert, Thanks for the info, you've confirmed what I was trying to do, but when I compile: ----------------------- #include <stdio.h> int main(int argc, char *argv[]) { printf("yo\n"); return 0; } ----------------------- without "-c" (llvm-gcc t1.c -o t1) the dissassembled bytecode does not call __main: ----------------------- ; ModuleID =

The problem I'm experiencing with Stacker has to do with linkage types (again!). What I'm trying to do is create a "global appending" array. In compilation units that don't include "main", I generate it with: TheStack = new GlobalVariable( /*type=*/ stack_type, /*isConstant=*/ false, /*Linkage=*/

So, I was in the process of writing a custom LLVM pass (my first one, yay!) to handle the problem of measuring the length of an appending linkage array. The approach I was taking was pretty simple: Iterate through all of the module's global variables until I find one that is trying to calculate the end of an appending-linkage array, which looks like this: @_moduleListEnd = constant [1 x

On Tue, May 24, 2016 at 2:28 PM, Chris Bieneman <beanz at apple.com> wrote: > Jack, > > What version of CMake are you using? > > -Chris Chris, I am using cmake 3.5.2. My read of this problem is as follows. While libLLVM.dylib is being linked against -lxar when -DLLVM_LINK_LLVM_DYLIB:BOOL=ON is passed to cmake, the libLLVM.dylib is created with -Wl,-dead_strip such that