[clang] [Driver][HIP] Do not pass -dependency-file flag for HIP Device offloading (PR #125646)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-clang-driver

@llvm/pr-subscribers-clang

Author: Aniket Lal (lalaniket8)

<details>
<summary>Changes</summary>

When we launch hipcc with multiple offload architectures along with -MF dep_file flag, the clang compilation invocations for host and device offloads write to the same dep_file, and can lead to collision during file IO operations. This can typically happen during large workloads. This commit provides a fix to generate dep_file only in host compilation.

---
Full diff: https://github.com/llvm/llvm-project/pull/125646.diff


1 Files Affected:

- (modified) clang/lib/Driver/ToolChains/Clang.cpp (+16-14) 


``````````diff
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index 9b5132c5625faa0..895fd0d7a180ee7 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -1013,21 +1013,23 @@ void Clang::AddPreprocessingOptions(Compilation &C, const JobAction &JA,
     ArgM = ArgMD;
 
   if (ArgM) {
-    // Determine the output location.
-    const char *DepFile;
-    if (Arg *MF = Args.getLastArg(options::OPT_MF)) {
-      DepFile = MF->getValue();
-      C.addFailureResultFile(DepFile, &JA);
-    } else if (Output.getType() == types::TY_Dependencies) {
-      DepFile = Output.getFilename();
-    } else if (!ArgMD) {
-      DepFile = "-";
-    } else {
-      DepFile = getDependencyFileName(Args, Inputs);
-      C.addFailureResultFile(DepFile, &JA);
+    if (!JA.isDeviceOffloading(Action::OFK_HIP)) {
+      // Determine the output location.
+      const char *DepFile;
+      if (Arg *MF = Args.getLastArg(options::OPT_MF)) {
+        DepFile = MF->getValue();
+        C.addFailureResultFile(DepFile, &JA);
+      } else if (Output.getType() == types::TY_Dependencies) {
+        DepFile = Output.getFilename();
+      } else if (!ArgMD) {
+        DepFile = "-";
+      } else {
+        DepFile = getDependencyFileName(Args, Inputs);
+        C.addFailureResultFile(DepFile, &JA);
+      }
+      CmdArgs.push_back("-dependency-file");
+      CmdArgs.push_back(DepFile);
     }
-    CmdArgs.push_back("-dependency-file");
-    CmdArgs.push_back(DepFile);
 
     bool HasTarget = false;
     for (const Arg *A : Args.filtered(options::OPT_MT, options::OPT_MQ)) {

``````````

</details>


https://github.com/llvm/llvm-project/pull/125646