[llvm] r266856 - ThinLTO: never promote as external weak

[Teresa Johnson via llvm-commits]

On Tue, Apr 19, 2016 at 9:18 PM, Mehdi Amini via llvm-commits <
llvm-commits at lists.llvm.org> wrote:

> Author: mehdi_amini
> Date: Tue Apr 19 23:18:11 2016
> New Revision: 266856
>
> URL: http://llvm.org/viewvc/llvm-project?rev=266856&view=rev
> Log:
> ThinLTO: never promote as external weak
>
> This linkage is *not* intended to express that a declaration refers
> to a weak symbol, but that the symbol might not be present at link
> time. I don't believe it was the intent.
>

In fact, this was the intent. WeakAny linkage is used for defined symbols
with __attribute__((weak)), which may not have a definition. The
corresponding declaration should be ExternalWeak.


> From: Mehdi Amini <mehdi.amini at apple.com>
>
> Modified:
>     llvm/trunk/lib/Transforms/Utils/FunctionImportUtils.cpp
>     llvm/trunk/test/Linker/funcimport.ll
>
> Modified: llvm/trunk/lib/Transforms/Utils/FunctionImportUtils.cpp
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/FunctionImportUtils.cpp?rev=266856&r1=266855&r2=266856&view=diff
>
> ==============================================================================
> --- llvm/trunk/lib/Transforms/Utils/FunctionImportUtils.cpp (original)
> +++ llvm/trunk/lib/Transforms/Utils/FunctionImportUtils.cpp Tue Apr 19
> 23:18:11 2016
> @@ -132,7 +132,7 @@ FunctionImportGlobalProcessing::getLinka
>      // linker. The module linking caller needs to enforce this.
>      assert(!doImportAsDefinition(SGV));
>      // If imported as a declaration, it becomes external_weak.
> -    return GlobalValue::ExternalWeakLinkage;
> +    return SGV->getLinkage();
>
>    case GlobalValue::WeakODRLinkage:
>      // For weak_odr linkage, there is a guarantee that all copies will be
>
> Modified: llvm/trunk/test/Linker/funcimport.ll
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Linker/funcimport.ll?rev=266856&r1=266855&r2=266856&view=diff
>
> ==============================================================================
> --- llvm/trunk/test/Linker/funcimport.ll (original)
> +++ llvm/trunk/test/Linker/funcimport.ll Tue Apr 19 23:18:11 2016
> @@ -98,7 +98,7 @@
>  ; reference should turned into an external_weak declaration.
>  ; RUN: llvm-link %t2.bc -summary-index=%t3.thinlto.bc
> -import=callweakfunc:%t.bc -import=weakfunc:%t.bc -S 2>&1 | FileCheck %s
> --check-prefix=IMPORTWEAKFUNC
>  ; IMPORTWEAKFUNC-DAG: Ignoring import request for weak-any function
> weakfunc
> -; IMPORTWEAKFUNC-DAG: declare extern_weak void @weakfunc
> +; IMPORTWEAKFUNC-DAG: declare void @weakfunc
>  ; IMPORTWEAKFUNC-DAG: define available_externally void @callweakfunc
>  ; IMPORTWEAKFUNC-NOT: @weakvar = extern_weak global i32, align 4
>
>
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits
>



-- 
Teresa Johnson |  Software Engineer |  tejohnson at google.com |  408-460-2413
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20160419/cfe1942e/attachment.html>