[PATCH] D95970: [HIP] Allow undefined symbols

[Yaxun Liu via Phabricator via cfe-commits]

yaxunl created this revision.
yaxunl added a reviewer: tra.
yaxunl requested review of this revision.

HIP managed variables need to be emitted as undefined symbols
since runtime needs to define them with managed memory
accessible by both device and host.

Let HIP toolchain allow that with lld.


https://reviews.llvm.org/D95970

Files:
  clang/lib/Driver/ToolChains/HIP.cpp
  clang/test/Driver/hip-toolchain-device-only.hip
  clang/test/Driver/hip-toolchain-no-rdc.hip


Index: clang/test/Driver/hip-toolchain-no-rdc.hip
===================================================================
--- clang/test/Driver/hip-toolchain-no-rdc.hip
+++ clang/test/Driver/hip-toolchain-no-rdc.hip
@@ -50,7 +50,7 @@
 // CHECK-NOT: {{".*opt"}}
 // CHECK-NOT: {{".*llc"}}
 
-// CHECK: [[LLD: ".*lld.*"]] "-flavor" "gnu" "--no-undefined" "-shared"
+// CHECK: [[LLD: ".*lld.*"]] "-flavor" "gnu" "-shared"
 // CHECK-SAME: "-o" "[[IMG_DEV_A_803:.*out]]" [[OBJ_DEV_A_803]]
 
 //
@@ -73,7 +73,7 @@
 // CHECK-NOT: {{".*opt"}}
 // CHECK-NOT: {{".*llc"}}
 
-// CHECK: [[LLD]] "-flavor" "gnu" "--no-undefined" "-shared"
+// CHECK: [[LLD]] "-flavor" "gnu" "-shared"
 // CHECK-SAME: "-o" "[[IMG_DEV_A_900:.*out]]" [[OBJ_DEV_A_900]]
 
 //
@@ -113,7 +113,7 @@
 // CHECK-NOT: {{".*opt"}}
 // CHECK-NOT: {{".*llc"}}
 
-// CHECK: [[LLD]] "-flavor" "gnu" "--no-undefined" "-shared"
+// CHECK: [[LLD]] "-flavor" "gnu" "-shared"
 // CHECK-SAME: "-o" "[[IMG_DEV_B_803:.*out]]" [[OBJ_DEV_B_803]]
 
 //
@@ -136,7 +136,7 @@
 // CHECK-NOT: {{".*opt"}}
 // CHECK-NOT: {{".*llc"}}
 
-// CHECK: [[LLD]] "-flavor" "gnu" "--no-undefined" "-shared"
+// CHECK: [[LLD]] "-flavor" "gnu" "-shared"
 // CHECK-SAME: "-o" "[[IMG_DEV_B_900:.*out]]" [[OBJ_DEV_B_900]]
 
 //
Index: clang/test/Driver/hip-toolchain-device-only.hip
===================================================================
--- clang/test/Driver/hip-toolchain-device-only.hip
+++ clang/test/Driver/hip-toolchain-device-only.hip
@@ -12,7 +12,7 @@
 // CHECK-SAME: "-target-cpu" "gfx803"
 // CHECK-SAME: {{.*}} "-o" [[OBJ_DEV_A_803:".*o"]] "-x" "hip"
 
-// CHECK: [[LLD: ".*lld.*"]] "-flavor" "gnu" "--no-undefined" "-shared"
+// CHECK: [[LLD: ".*lld.*"]] "-flavor" "gnu" "-shared"
 // CHECK-SAME: "-o" "[[IMG_DEV_A_803:.*out]]" [[OBJ_DEV_A_803]]
 
 // CHECK: [[CLANG:".*clang.*"]] "-cc1"{{.*}} "-triple" "amdgcn-amd-amdhsa"
@@ -21,7 +21,7 @@
 // CHECK-SAME: "-target-cpu" "gfx900"
 // CHECK-SAME: {{.*}} "-o" [[OBJ_DEV_A_900:".*o"]] "-x" "hip"
 
-// CHECK: [[LLD]] "-flavor" "gnu" "--no-undefined" "-shared"
+// CHECK: [[LLD]] "-flavor" "gnu" "-shared"
 // CHECK-SAME: "-o" "[[IMG_DEV_A_900:.*out]]" [[OBJ_DEV_A_900]]
 
 // CHECK: [[BUNDLER:".*clang-offload-bundler"]] "-type=o"
Index: clang/lib/Driver/ToolChains/HIP.cpp
===================================================================
--- clang/lib/Driver/ToolChains/HIP.cpp
+++ clang/lib/Driver/ToolChains/HIP.cpp
@@ -60,7 +60,9 @@
                                           const llvm::opt::ArgList &Args) const {
   // Construct lld command.
   // The output from ld.lld is an HSA code object file.
-  ArgStringList LldArgs{"-flavor", "gnu", "--no-undefined", "-shared",
+  // Do not use --no-undefined option since managed variables need to be emitted
+  // as undefined symbols.
+  ArgStringList LldArgs{"-flavor", "gnu", "-shared",
                         "-plugin-opt=-amdgpu-internalize-symbols"};
 
   auto &TC = getToolChain();


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