[llvm] [Offload] Store kernel name in GenericKernelTy (PR #142799)

[Ross Brunton via llvm-commits]

https://github.com/RossBrunton created https://github.com/llvm/llvm-project/pull/142799

GenericKernelTy has a pointer to the name that was used to create it.
However, the name passed in as an argument may not outlive the kernel.
Instead, GenericKernelTy now contains a SmallString, and copies the
name into there.


>From 4998fed5030355a4c0e8d0dc8f925ecc9ef1b1a6 Mon Sep 17 00:00:00 2001
From: Ross Brunton <ross at codeplay.com>
Date: Wed, 4 Jun 2025 16:41:50 +0100
Subject: [PATCH] [Offload] Store kernel name in GenericKernelTy

GenericKernelTy has a pointer to the name that was used to create it.
However, the name passed in as an argument may not outlive the kernel.
Instead, GenericKernelTy now contains a SmallString, and copies the
name into there.
---
 .../plugins-nextgen/common/include/PluginInterface.h  | 11 ++++++++---
 .../plugins-nextgen/common/src/PluginInterface.cpp    |  2 +-
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/offload/plugins-nextgen/common/include/PluginInterface.h b/offload/plugins-nextgen/common/include/PluginInterface.h
index d2437908a0a6f..88dd516697f57 100644
--- a/offload/plugins-nextgen/common/include/PluginInterface.h
+++ b/offload/plugins-nextgen/common/include/PluginInterface.h
@@ -256,7 +256,12 @@ class DeviceImageTy {
 struct GenericKernelTy {
   /// Construct a kernel with a name and a execution mode.
   GenericKernelTy(const char *Name)
-      : Name(Name), PreferredNumThreads(0), MaxNumThreads(0) {}
+      : Name(Name), PreferredNumThreads(0), MaxNumThreads(0) {
+    // Ensure that the name is null terminated so getName() can just return the
+    // pointer
+    this->Name.push_back('\0');
+    this->Name.pop_back();
+  }
 
   virtual ~GenericKernelTy() {}
 
@@ -277,7 +282,7 @@ struct GenericKernelTy {
                            AsyncInfoWrapperTy &AsyncInfoWrapper) const = 0;
 
   /// Get the kernel name.
-  const char *getName() const { return Name; }
+  const char *getName() const { return Name.data(); }
 
   /// Get the kernel image.
   DeviceImageTy &getImage() const {
@@ -373,7 +378,7 @@ struct GenericKernelTy {
   }
 
   /// The kernel name.
-  const char *Name;
+  SmallString<32> Name;
 
   /// The image that contains this kernel.
   DeviceImageTy *ImagePtr = nullptr;
diff --git a/offload/plugins-nextgen/common/src/PluginInterface.cpp b/offload/plugins-nextgen/common/src/PluginInterface.cpp
index f9e316adad8f4..9170a6a75d140 100644
--- a/offload/plugins-nextgen/common/src/PluginInterface.cpp
+++ b/offload/plugins-nextgen/common/src/PluginInterface.cpp
@@ -456,7 +456,7 @@ Error GenericKernelTy::init(GenericDeviceTy &GenericDevice,
     KernelEnvironment = KernelEnvironmentTy{};
     DP("Failed to read kernel environment for '%s' Using default Bare (0) "
        "execution mode\n",
-       Name);
+       getName());
   }
 
   // Max = Config.Max > 0 ? min(Config.Max, Device.Max) : Device.Max;