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

This PR uses the VFS to create the OpenMP target entry instead of going
straight to the real file system. This matches the behavior of other
input files of the compiler.

Author: jansvoboda11

clang/lib/CodeGen/CGOpenMPRuntime.cpp

@@ -1547,7 +1547,8 @@ 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) {

llvm/include/llvm/Frontend/OpenMP/OMPIRBuilder.h

@@ -1350,7 +1350,7 @@ 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 };

llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp

@@ -9849,17 +9849,19 @@ 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));

mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp

@@ -3534,8 +3534,10 @@ 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(fileInfoCallBack, *vfs).FileID);
   }
   os << "_decl_tgt_ref_ptr";
 
@@ -5809,10 +5811,12 @@ 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(fileInfoCallBack, *vfs),
+          mangledName, generatedRefs, /*OpenMPSimd*/ false, targetTriple,
           /*GlobalInitializer*/ nullptr, /*VariableLinkage*/ nullptr,
           gVal->getType(), gVal);
 
@@ -5822,9 +5826,9 @@ 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(fileInfoCallBack, *vfs),
+            mangledName, generatedRefs, /*OpenMPSimd*/ false, targetTriple,
+            gVal->getType(), /*GlobalInitializer*/ nullptr,
             /*VariableLinkage*/ nullptr);
       }
     }