[clang] [SPIRV][ClangLinkerWrapper] Pass --allow-partial-linkage to spirv-link (PR #181870)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Nick Sarnie (sarnex)

<details>
<summary>Changes</summary>

Without this flag a lot of tests error in the linker.

---
Full diff: https://github.com/llvm/llvm-project/pull/181870.diff


2 Files Affected:

- (added) clang/test/Tooling/clang-linker-wrapper-spirv.cpp (+10) 
- (modified) clang/tools/clang-linker-wrapper/ClangLinkerWrapper.cpp (+7) 


``````````diff
diff --git a/clang/test/Tooling/clang-linker-wrapper-spirv.cpp b/clang/test/Tooling/clang-linker-wrapper-spirv.cpp
new file mode 100644
index 0000000000000..80cc598eeedcf
--- /dev/null
+++ b/clang/test/Tooling/clang-linker-wrapper-spirv.cpp
@@ -0,0 +1,10 @@
+// Verify spirv-link flags when called from clang-linker-wrapper
+// REQUIRES: system-linux
+// REQUIRES: spirv-tools
+// REQUIRES: spirv-registered-target
+// RUN: %clangxx -fopenmp -fopenmp-targets=spirv64-intel -nogpulib -v -o %t.o %s 2>&1 | FileCheck %s
+
+// CHECK: spirv-link{{.*}} --allow-partial-linkage
+int main(int argc, char** argv) {
+  return 0;
+}
diff --git a/clang/tools/clang-linker-wrapper/ClangLinkerWrapper.cpp b/clang/tools/clang-linker-wrapper/ClangLinkerWrapper.cpp
index 619e539857fc6..1e521a4a25418 100644
--- a/clang/tools/clang-linker-wrapper/ClangLinkerWrapper.cpp
+++ b/clang/tools/clang-linker-wrapper/ClangLinkerWrapper.cpp
@@ -528,6 +528,13 @@ Expected<StringRef> clang(ArrayRef<StringRef> InputFiles, const ArgList &Args,
   if (!Triple.isNVPTX() && !Triple.isSPIRV())
     CmdArgs.push_back("-Wl,--no-undefined");
 
+  if (Triple.isSPIRV()) {
+    // Some functions are provided by the GPU runtime, so
+    // allow some functions to be undefined.
+    CmdArgs.push_back("-Xlinker");
+    CmdArgs.push_back("--allow-partial-linkage");
+  }
+
   for (StringRef InputFile : InputFiles)
     CmdArgs.push_back(InputFile);
 

``````````

</details>


https://github.com/llvm/llvm-project/pull/181870