[PATCH] D145941: [Clang] Always use -zdefs when linking AMDGPU images

[Joseph Huber via Phabricator via cfe-commits]

jhuber6 created this revision.
jhuber6 added reviewers: jdoerfert, JonChesterfield, arsenm, yaxunl, MaskRay.
Herald added subscribers: kosarev, kerbowa, tpr, dstuttard, jvesely, kzhuravl.
Herald added a project: All.
jhuber6 requested review of this revision.
Herald added subscribers: cfe-commits, wdng.
Herald added a project: clang.

AMDGPU uses ELF shared libraries to implement their executable device
images. One downside to this method is that it disables regular warnings
on undefined symbols. This is because shared libraries expect these to
be resolves by later loads. However, the GPU images do not support
dynamic linking so any undefined symbol is going to cause a runtime
error. This patch adds `-zdefs` to the `ld.lld` invocation to guaruntee
that undefined symbols are always caught as linking errors rather than
runtime errors.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D145941

Files:
  clang/lib/Driver/ToolChains/AMDGPU.cpp
  clang/test/Driver/amdgpu-toolchain.c


Index: clang/test/Driver/amdgpu-toolchain.c
===================================================================
--- clang/test/Driver/amdgpu-toolchain.c
+++ clang/test/Driver/amdgpu-toolchain.c
@@ -6,7 +6,7 @@
 // RUN: %clang -### -g --target=amdgcn-mesa-mesa3d -mcpu=kaveri %s 2>&1 | FileCheck -check-prefix=DWARF_VER %s
 
 // AS_LINK: "-cc1as"
-// AS_LINK: ld.lld{{.*}} "-shared"
+// AS_LINK: ld.lld{{.*}} "-shared" "-zdefs"
 
 // DWARF_VER: "-dwarf-version=5"
 
Index: clang/lib/Driver/ToolChains/AMDGPU.cpp
===================================================================
--- clang/lib/Driver/ToolChains/AMDGPU.cpp
+++ clang/lib/Driver/ToolChains/AMDGPU.cpp
@@ -544,6 +544,7 @@
     addLTOOptions(getToolChain(), Args, CmdArgs, Output, Inputs[0],
                   C.getDriver().getLTOMode() == LTOK_Thin);
   CmdArgs.push_back("-shared");
+  CmdArgs.push_back("-zdefs");
   CmdArgs.push_back("-o");
   CmdArgs.push_back(Output.getFilename());
   C.addCommand(std::make_unique<Command>(


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D145941.504653.patch
Type: text/x-patch
Size: 995 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20230313/46c6d271/attachment.bin>