[lld] 056ebad - [HIP] Fix lld failure when devie object is empty
Yaxun Liu via llvm-commits
llvm-commits at lists.llvm.org
Tue Nov 22 07:39:16 PST 2022
Author: Yaxun (Sam) Liu
Date: 2022-11-22T10:38:42-05:00
New Revision: 056ebadf5c75df6568ea3dda879518e1edc1f48f
URL: https://github.com/llvm/llvm-project/commit/056ebadf5c75df6568ea3dda879518e1edc1f48f
DIFF: https://github.com/llvm/llvm-project/commit/056ebadf5c75df6568ea3dda879518e1edc1f48f.diff
LOG: [HIP] Fix lld failure when devie object is empty
When -fgpu-rdc is used for linking relocatable objects, clang driver launches
clang-offload-bundler to extract a device relocatable object from each input
relocatable object file and passes the extracted files to lld. The input relocatable
object file could either come from HIP program or C++ program. The relocatable
object file from C++ program does not contain device relocatable objects, therefore
clang-offload-bundler extracts an empty file and passes it to lld. lld treates
empty file as linker script. When there is no object input file to lld, lld
will emit error:
target emulation unknown: -m or at least one .o file required
This patch adds "elf64_amdgpu" to lld so that lld always know the target
no matter whether there are object input files or not.
Reviewed by: Artem Belevich, Fangrui Song
Differential Revision: https://reviews.llvm.org/D138221
Added:
lld/test/ELF/emulation-amdgpu.s
Modified:
clang/lib/Driver/ToolChains/HIPAMD.cpp
clang/test/Driver/hip-toolchain-device-only.hip
clang/test/Driver/hip-toolchain-no-rdc.hip
lld/ELF/Driver.cpp
Removed:
################################################################################
diff --git a/clang/lib/Driver/ToolChains/HIPAMD.cpp b/clang/lib/Driver/ToolChains/HIPAMD.cpp
index 1951ac12515d8..c64421d259ce1 100644
--- a/clang/lib/Driver/ToolChains/HIPAMD.cpp
+++ b/clang/lib/Driver/ToolChains/HIPAMD.cpp
@@ -108,7 +108,12 @@ void AMDGCN::Linker::constructLldCommand(Compilation &C, const JobAction &JA,
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",
+ ArgStringList LldArgs{"-flavor",
+ "gnu",
+ "-m",
+ "elf64_amdgpu",
+ "--no-undefined",
+ "-shared",
"-plugin-opt=-amdgpu-internalize-symbols"};
auto &TC = getToolChain();
diff --git a/clang/test/Driver/hip-toolchain-device-only.hip b/clang/test/Driver/hip-toolchain-device-only.hip
index 9e4a36f9628b9..c6ff67bde738c 100644
--- a/clang/test/Driver/hip-toolchain-device-only.hip
+++ b/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" "-m" "elf64_amdgpu" "--no-undefined" "-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" "-m" "elf64_amdgpu" "--no-undefined" "-shared"
// CHECK-SAME: "-o" "[[IMG_DEV_A_900:.*out]]" [[OBJ_DEV_A_900]]
// CHECK: [[BUNDLER:".*clang-offload-bundler"]] "-type=o"
diff --git a/clang/test/Driver/hip-toolchain-no-rdc.hip b/clang/test/Driver/hip-toolchain-no-rdc.hip
index 2cd44ca78eb8d..4ae054b62fb7f 100644
--- a/clang/test/Driver/hip-toolchain-no-rdc.hip
+++ b/clang/test/Driver/hip-toolchain-no-rdc.hip
@@ -59,7 +59,7 @@
// CHECK-NOT: {{".*opt"}}
// CHECK-NOT: {{".*llc"}}
-// CHECK: [[LLD: ".*lld.*"]] "-flavor" "gnu" "--no-undefined" "-shared"
+// CHECK: [[LLD: ".*lld.*"]] "-flavor" "gnu" "-m" "elf64_amdgpu" "--no-undefined" "-shared"
// CHECK-SAME: "-o" "[[IMG_DEV_A_803:.*out]]" [[OBJ_DEV_A_803]]
//
@@ -82,7 +82,7 @@
// CHECK-NOT: {{".*opt"}}
// CHECK-NOT: {{".*llc"}}
-// CHECK: [[LLD]] "-flavor" "gnu" "--no-undefined" "-shared"
+// CHECK: [[LLD]] "-flavor" "gnu" "-m" "elf64_amdgpu" "--no-undefined" "-shared"
// CHECK-SAME: "-o" "[[IMG_DEV_A_900:.*out]]" [[OBJ_DEV_A_900]]
//
@@ -122,7 +122,7 @@
// CHECK-NOT: {{".*opt"}}
// CHECK-NOT: {{".*llc"}}
-// CHECK: [[LLD]] "-flavor" "gnu" "--no-undefined" "-shared"
+// CHECK: [[LLD]] "-flavor" "gnu" "-m" "elf64_amdgpu" "--no-undefined" "-shared"
// CHECK-SAME: "-o" "[[IMG_DEV_B_803:.*out]]" [[OBJ_DEV_B_803]]
//
@@ -145,7 +145,7 @@
// CHECK-NOT: {{".*opt"}}
// CHECK-NOT: {{".*llc"}}
-// CHECK: [[LLD]] "-flavor" "gnu" "--no-undefined" "-shared"
+// CHECK: [[LLD]] "-flavor" "gnu" "-m" "elf64_amdgpu" "--no-undefined" "-shared"
// CHECK-SAME: "-o" "[[IMG_DEV_B_900:.*out]]" [[OBJ_DEV_B_900]]
//
diff --git a/lld/ELF/Driver.cpp b/lld/ELF/Driver.cpp
index f9792ac6b7483..b8cc8ef24b7e7 100644
--- a/lld/ELF/Driver.cpp
+++ b/lld/ELF/Driver.cpp
@@ -176,12 +176,15 @@ static std::tuple<ELFKind, uint16_t, uint8_t> parseEmulation(StringRef emul) {
.Case("elf_iamcu", {ELF32LEKind, EM_IAMCU})
.Case("elf64_sparc", {ELF64BEKind, EM_SPARCV9})
.Case("msp430elf", {ELF32LEKind, EM_MSP430})
+ .Case("elf64_amdgpu", {ELF64LEKind, EM_AMDGPU})
.Default({ELFNoneKind, EM_NONE});
if (ret.first == ELFNoneKind)
error("unknown emulation: " + emul);
if (ret.second == EM_MSP430)
osabi = ELFOSABI_STANDALONE;
+ else if (ret.second == EM_AMDGPU)
+ osabi = ELFOSABI_AMDGPU_HSA;
return std::make_tuple(ret.first, ret.second, osabi);
}
diff --git a/lld/test/ELF/emulation-amdgpu.s b/lld/test/ELF/emulation-amdgpu.s
new file mode 100644
index 0000000000000..707f0aeb909ef
--- /dev/null
+++ b/lld/test/ELF/emulation-amdgpu.s
@@ -0,0 +1,36 @@
+# REQUIRES: amdgpu
+
+# RUN: llvm-mc -filetype=obj -triple=amdgcn-amd-amdhsa %s -o %t.o
+# RUN: ld.lld %t.o -o %t
+# RUN: llvm-readobj --file-headers %t | FileCheck %s
+# RUN: ld.lld -m elf64_amdgpu %t.o -o %t
+# RUN: llvm-readobj --file-headers %t | FileCheck %s
+
+# CHECK: ElfHeader {
+# CHECK-NEXT: Ident {
+# CHECK-NEXT: Magic: (7F 45 4C 46)
+# CHECK-NEXT: Class: 64-bit (0x2)
+# CHECK-NEXT: DataEncoding: LittleEndian (0x1)
+# CHECK-NEXT: FileVersion: 1
+# CHECK-NEXT: OS/ABI: AMDGPU_HSA (0x40)
+# CHECK-NEXT: ABIVersion: 2
+# CHECK-NEXT: Unused: (00 00 00 00 00 00 00)
+# CHECK-NEXT: }
+# CHECK-NEXT: Type: Executable (0x2)
+# CHECK-NEXT: Machine: EM_AMDGPU (0xE0)
+# CHECK-NEXT: Version: 1
+# CHECK-NEXT: Entry:
+# CHECK-NEXT: ProgramHeaderOffset: 0x40
+# CHECK-NEXT: SectionHeaderOffset:
+# CHECK-NEXT: Flags [ (0x0)
+# CHECK-NEXT: ]
+# CHECK-NEXT: HeaderSize: 64
+# CHECK-NEXT: ProgramHeaderEntrySize: 56
+# CHECK-NEXT: ProgramHeaderCount:
+# CHECK-NEXT: SectionHeaderEntrySize: 64
+# CHECK-NEXT: SectionHeaderCount:
+# CHECK-NEXT: StringTableSectionIndex:
+# CHECK-NEXT: }
+
+.globl _start
+_start:
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