[Openmp-commits] [openmp] [Libomptarget] Remove __tgt_image_info and use the ELF directly (PR #75720)

[Saiyedul Islam via Openmp-commits]

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@@ -26,52 +26,228 @@ using namespace llvm;
 using namespace llvm::ELF;
 using namespace llvm::object;
 
-/// If the given range of bytes [\p BytesBegin, \p BytesEnd) represents
-/// a valid ELF, then invoke \p Callback on the ELFObjectFileBase
-/// created from this range, otherwise, return 0.
-/// If \p Callback is invoked, then return whatever value \p Callback returns.
-template <typename F>
-static int32_t withBytesAsElf(char *BytesBegin, char *BytesEnd, F Callback) {
-  size_t Size = BytesEnd - BytesBegin;
-  StringRef StrBuf(BytesBegin, Size);
-
-  auto Magic = identify_magic(StrBuf);
-  if (Magic != file_magic::elf && Magic != file_magic::elf_relocatable &&
-      Magic != file_magic::elf_executable &&
-      Magic != file_magic::elf_shared_object && Magic != file_magic::elf_core) {
-    DP("Not an ELF image!\n");
-    return 0;
+bool utils::elf::isELF(StringRef Buffer) {
+  switch (identify_magic(Buffer)) {
+  case file_magic::elf:
+  case file_magic::elf_relocatable:
+  case file_magic::elf_executable:
+  case file_magic::elf_shared_object:
+  case file_magic::elf_core:
+    return true;
+  default:
+    return false;
   }
+}
 
-  std::unique_ptr<MemoryBuffer> MemBuf =
-      MemoryBuffer::getMemBuffer(StrBuf, "", false);
-  Expected<std::unique_ptr<ObjectFile>> BinOrErr =
-      ObjectFile::createELFObjectFile(MemBuf->getMemBufferRef(),
-                                      /*InitContent=*/false);
-  if (!BinOrErr) {
-    DP("Unable to get ELF handle: %s!\n",
-       toString(BinOrErr.takeError()).c_str());
-    return 0;
+Expected<bool> utils::elf::checkMachine(StringRef Object, uint16_t EMachine) {
+  if (!isELF(Object))
+    return createError("Input is not an ELF.");
+
+  Expected<ELF64LEObjectFile> ElfOrErr =
+      ELF64LEObjectFile::create(MemoryBufferRef(Object, /*Identifier=*/""),
+                                /*InitContent=*/false);
+  if (!ElfOrErr)
+    return ElfOrErr.takeError();
+
+  const auto Header = ElfOrErr->getELFFile().getHeader();
+  if (Header.e_ident[EI_CLASS] != ELFCLASS64)
+    return createError("Only 64-bit ELF files are supported");
+  if (Header.e_type != ET_EXEC && Header.e_type != ET_DYN)
+    return createError("Only executable ELF files are supported");
+
+  if (Header.e_machine == EM_AMDGPU) {
+    if (Header.e_ident[EI_OSABI] != ELFOSABI_AMDGPU_HSA)
+      return createError("Invalid AMD OS/ABI, must be AMDGPU_HSA");
+    if (Header.e_ident[EI_ABIVERSION] != ELFABIVERSION_AMDGPU_HSA_V4 &&
+        Header.e_ident[EI_ABIVERSION] != ELFABIVERSION_AMDGPU_HSA_V5)
+      return createError("Invalid AMD ABI version, must be version 4 or 5");
+    if ((Header.e_flags & EF_AMDGPU_MACH) < EF_AMDGPU_MACH_AMDGCN_GFX700 ||
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saiislam wrote:

Better to leave this check to the clang driver, backend, or hsa runtime. All archs between 700 and 1201 are not supported and it doesn't seem worth to check it again here.

https://github.com/llvm/llvm-project/pull/75720