[clang] [llvm] [mlir] [clang] Use the VFS to create the OpenMP region entry ID (PR #160918)

[Jan Svoboda via llvm-commits]

https://github.com/jansvoboda11 updated https://github.com/llvm/llvm-project/pull/160918

>From d149b833da496cb2749410b1692789c1075819f1 Mon Sep 17 00:00:00 2001
From: Jan Svoboda <jan_svoboda at apple.com>
Date: Thu, 25 Sep 2025 15:57:31 -0700
Subject: [PATCH 1/2] [clang] Use the VFS to create the OpenMP region entry ID

---
 clang/lib/CodeGen/CGOpenMPRuntime.cpp            |  3 ++-
 llvm/include/llvm/Frontend/OpenMP/OMPIRBuilder.h |  2 +-
 llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp        | 14 ++++++++------
 3 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/clang/lib/CodeGen/CGOpenMPRuntime.cpp b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
index c90e1a487daf9..9004296a7e453 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntime.cpp
+++ b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
@@ -1550,7 +1550,8 @@ static llvm::TargetRegionEntryInfo getEntryInfoFromPresumedLoc(
     return std::pair<std::string, uint64_t>(PLoc.getFilename(), PLoc.getLine());
   };
 
-  return OMPBuilder.getTargetEntryUniqueInfo(FileInfoCallBack, ParentName);
+  return OMPBuilder.getTargetEntryUniqueInfo(FileInfoCallBack,
+                                             *CGM.getFileSystem(), ParentName);
 }
 
 ConstantAddress CGOpenMPRuntime::getAddrOfDeclareTargetVar(const VarDecl *VD) {
diff --git a/llvm/include/llvm/Frontend/OpenMP/OMPIRBuilder.h b/llvm/include/llvm/Frontend/OpenMP/OMPIRBuilder.h
index f43ef932e965a..bfe1c8090acfe 100644
--- a/llvm/include/llvm/Frontend/OpenMP/OMPIRBuilder.h
+++ b/llvm/include/llvm/Frontend/OpenMP/OMPIRBuilder.h
@@ -1402,7 +1402,7 @@ class OpenMPIRBuilder {
   /// any.
   LLVM_ABI static TargetRegionEntryInfo
   getTargetEntryUniqueInfo(FileIdentifierInfoCallbackTy CallBack,
-                           StringRef ParentName = "");
+                           vfs::FileSystem &VFS, StringRef ParentName = "");
 
   /// Enum class for the RedctionGen CallBack type to be used.
   enum class ReductionGenCBKind { Clang, MLIR };
diff --git a/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp b/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp
index 9b67465faab0b..8fc1a99e4bc4c 100644
--- a/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp
+++ b/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp
@@ -10312,17 +10312,19 @@ void OffloadEntriesInfoManager::getTargetRegionEntryFnName(
 
 TargetRegionEntryInfo
 OpenMPIRBuilder::getTargetEntryUniqueInfo(FileIdentifierInfoCallbackTy CallBack,
+                                          vfs::FileSystem &VFS,
                                           StringRef ParentName) {
   sys::fs::UniqueID ID(0xdeadf17e, 0);
   auto FileIDInfo = CallBack();
   uint64_t FileID = 0;
-  std::error_code EC = sys::fs::getUniqueID(std::get<0>(FileIDInfo), ID);
-  // If the inode ID could not be determined, create a hash value
-  // the current file name and use that as an ID.
-  if (EC)
+  if (ErrorOr<vfs::Status> Status = VFS.status(std::get<0>(FileIDInfo))) {
+    ID = Status->getUniqueID();
+    FileID = Status->getUniqueID().getFile();
+  } else {
+    // If the inode ID could not be determined, create a hash value
+    // the current file name and use that as an ID.
     FileID = hash_value(std::get<0>(FileIDInfo));
-  else
-    FileID = ID.getFile();
+  }
 
   return TargetRegionEntryInfo(ParentName, ID.getDevice(), FileID,
                                std::get<1>(FileIDInfo));

>From 94b8dfc0c5077f84ade9ac440c48a8f55d0ea6f1 Mon Sep 17 00:00:00 2001
From: Jan Svoboda <jan_svoboda at apple.com>
Date: Fri, 26 Sep 2025 10:40:03 -0700
Subject: [PATCH 2/2] Fix MLIR build

---
 .../Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
index 4921a1990b6e8..39d88313f49dd 100644
--- a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
@@ -3595,8 +3595,10 @@ getDeclareTargetRefPtrSuffix(LLVM::GlobalOp globalOp,
           llvm::StringRef(loc.getFilename()), loc.getLine());
     };
 
+    auto vfs = llvm::vfs::getRealFileSystem();
     os << llvm::format(
-        "_%x", ompBuilder.getTargetEntryUniqueInfo(fileInfoCallBack).FileID);
+        "_%x",
+        ompBuilder.getTargetEntryUniqueInfo(*vfs, fileInfoCallBack).FileID);
   }
   os << "_decl_tgt_ref_ptr";
 
@@ -5888,10 +5890,12 @@ convertDeclareTargetAttr(Operation *op, mlir::omp::DeclareTargetAttr attribute,
                                                      lineNo);
       };
 
+      auto vfs = llvm::vfs::getRealFileSystem();
+
       ompBuilder->registerTargetGlobalVariable(
           captureClause, deviceClause, isDeclaration, isExternallyVisible,
-          ompBuilder->getTargetEntryUniqueInfo(fileInfoCallBack), mangledName,
-          generatedRefs, /*OpenMPSimd*/ false, targetTriple,
+          ompBuilder->getTargetEntryUniqueInfo(*vfs, fileInfoCallBack),
+          mangledName, generatedRefs, /*OpenMPSimd*/ false, targetTriple,
           /*GlobalInitializer*/ nullptr, /*VariableLinkage*/ nullptr,
           gVal->getType(), gVal);
 
@@ -5901,9 +5905,9 @@ convertDeclareTargetAttr(Operation *op, mlir::omp::DeclareTargetAttr attribute,
            ompBuilder->Config.hasRequiresUnifiedSharedMemory())) {
         ompBuilder->getAddrOfDeclareTargetVar(
             captureClause, deviceClause, isDeclaration, isExternallyVisible,
-            ompBuilder->getTargetEntryUniqueInfo(fileInfoCallBack), mangledName,
-            generatedRefs, /*OpenMPSimd*/ false, targetTriple, gVal->getType(),
-            /*GlobalInitializer*/ nullptr,
+            ompBuilder->getTargetEntryUniqueInfo(*vfs, fileInfoCallBack),
+            mangledName, generatedRefs, /*OpenMPSimd*/ false, targetTriple,
+            gVal->getType(), /*GlobalInitializer*/ nullptr,
             /*VariableLinkage*/ nullptr);
       }
     }