[Mlir-commits] [flang] [mlir] [flang][OpenMP] Fix missing missing inode issue (PR #130798)

[Michael Klemm]

https://github.com/mjklemm created https://github.com/llvm/llvm-project/pull/130798

When outlining an offload region, Flang creates a unique name by querying an inode ID.  However, when the name of the actual source file does not match the logical file in a `#line` preprocessor directive, code-gen was failing as it could not determine the inode ID.  This PR checks for this condition and if the logical file name does not exist, the inode is replaced with a hash value created from the source code itself.

>From b1ae37116b234d04071a5277d36dbdba3d476666 Mon Sep 17 00:00:00 2001
From: Michael Klemm <michael.klemm at amd.com>
Date: Tue, 11 Mar 2025 14:32:22 +0100
Subject: [PATCH 1/2] Fix compiler error when source file does not exist

---
 .../OpenMP/OpenMPToLLVMIRTranslation.cpp      | 20 +++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
index 3373f19a006ba..5e2879b6787ee 100644
--- a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
@@ -4284,7 +4284,7 @@ LogicalResult convertFlagsAttr(Operation *op, mlir::omp::FlagsAttr attribute,
   return success();
 }
 
-static bool getTargetEntryUniqueInfo(llvm::TargetRegionEntryInfo &targetInfo,
+static void getTargetEntryUniqueInfo(llvm::TargetRegionEntryInfo &targetInfo,
                                      omp::TargetOp targetOp,
                                      llvm::StringRef parentName = "") {
   auto fileLoc = targetOp.getLoc()->findInstanceOf<FileLineColLoc>();
@@ -4293,15 +4293,16 @@ static bool getTargetEntryUniqueInfo(llvm::TargetRegionEntryInfo &targetInfo,
   StringRef fileName = fileLoc.getFilename().getValue();
 
   llvm::sys::fs::UniqueID id;
+  uint64_t line = fileLoc.getLine();
   if (auto ec = llvm::sys::fs::getUniqueID(fileName, id)) {
-    targetOp.emitError("Unable to get unique ID for file");
-    return false;
+    size_t fileHash = llvm::hash_value(fileName.str());
+    size_t deviceId = 0xdeadf17e;
+    targetInfo =
+        llvm::TargetRegionEntryInfo(parentName, deviceId, fileHash, line);
+  } else {
+    targetInfo = llvm::TargetRegionEntryInfo(parentName, id.getDevice(),
+                                             id.getFile(), line);
   }
-
-  uint64_t line = fileLoc.getLine();
-  targetInfo = llvm::TargetRegionEntryInfo(parentName, id.getDevice(),
-                                           id.getFile(), line);
-  return true;
 }
 
 static void
@@ -4901,8 +4902,7 @@ convertOmpTarget(Operation &opInst, llvm::IRBuilderBase &builder,
 
   llvm::TargetRegionEntryInfo entryInfo;
 
-  if (!getTargetEntryUniqueInfo(entryInfo, targetOp, parentName))
-    return failure();
+  getTargetEntryUniqueInfo(entryInfo, targetOp, parentName);
 
   MapInfoData mapData;
   collectMapDataFromMapOperands(mapData, mapVars, moduleTranslation, dl,

>From ec0aad752f6ca759071e2b3e8cb3920b13d2519c Mon Sep 17 00:00:00 2001
From: Michael Klemm <michael.klemm at amd.com>
Date: Tue, 11 Mar 2025 17:48:16 +0100
Subject: [PATCH 2/2] Add simplistic test

---
 flang/test/Lower/OpenMP/missing-inode.f90 | 8 ++++++++
 1 file changed, 8 insertions(+)
 create mode 100644 flang/test/Lower/OpenMP/missing-inode.f90

diff --git a/flang/test/Lower/OpenMP/missing-inode.f90 b/flang/test/Lower/OpenMP/missing-inode.f90
new file mode 100644
index 0000000000000..01e662557cfe6
--- /dev/null
+++ b/flang/test/Lower/OpenMP/missing-inode.f90
@@ -0,0 +1,8 @@
+! RUN: %flang_fc1 -emit-llvm -fopenmp -fopenmp-version=51 -fopenmp-targets=amdgcn-amd-amdhsa -o - %s | FileCheck %s
+program missing_inode
+#line "/this_path_should_not_exist_on_any_system_out_there/and_if_it_does_it_will_break_the/tes.f90" 700
+    ! CHECK:  define internal void @__omp_offloading_{{[0-9a-f]+}}_{{[0-9a-f]+}}__QQmain_l701
+    !$omp target
+        call some_routine()
+    !$omp end target
+end program missing_inode
\ No newline at end of file