[PATCH] D69192: llvm-objdump can error out with an unexpected EOF error if .bss is larger than the file being dumped.

[Fangrui Song via Phabricator via llvm-commits]

This revision was automatically updated to reflect the committed changes.
Closed by commit rG6cd47f9dd7dd: [llvm-objdump] Fix spurious "The end of the file was unexpectedly encountered"… (authored by sidneym, committed by MaskRay).

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D69192/new/

https://reviews.llvm.org/D69192

Files:
  llvm/include/llvm/Object/ELFObjectFile.h
  llvm/test/tools/llvm-objdump/X86/elf-disassemble-bss.test


Index: llvm/test/tools/llvm-objdump/X86/elf-disassemble-bss.test
===================================================================
--- /dev/null
+++ llvm/test/tools/llvm-objdump/X86/elf-disassemble-bss.test
@@ -0,0 +1,37 @@
+## Check that when BSS is larger than the file llvm-objdump doesn't
+## assert with an unexpected end of file error.
+# RUN: yaml2obj --docnum=1 %s > %t
+# RUN: yaml2obj --docnum=2 %s > %t.2
+# RUN: llvm-objdump -D %t | FileCheck %s
+# RUN: llvm-objdump -D %t.2 | FileCheck %s
+
+# CHECK: Disassembly of section .bss:
+# CHECK: .bss:
+# CHECK-NEXT: ...
+
+--- !ELF
+FileHeader:
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  Type:            ET_EXEC
+  Machine:         EM_X86_64
+Sections:
+  - Name:            .bss
+    Type:            SHT_NOBITS
+    Flags:           [ SHF_WRITE, SHF_ALLOC ]
+    Size:            0x0000000000001000
+...
+
+--- !ELF
+FileHeader:
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  Type:            ET_EXEC
+  Machine:         EM_X86_64
+Sections:
+  - Name:            .bss
+    Type:            SHT_NOBITS
+    Flags:           [ SHF_WRITE, SHF_ALLOC ]
+    Size:            0x0000000000001000
+    ShOffset:        0x0000000080000000
+...
Index: llvm/include/llvm/Object/ELFObjectFile.h
===================================================================
--- llvm/include/llvm/Object/ELFObjectFile.h
+++ llvm/include/llvm/Object/ELFObjectFile.h
@@ -723,6 +723,8 @@
 Expected<ArrayRef<uint8_t>>
 ELFObjectFile<ELFT>::getSectionContents(DataRefImpl Sec) const {
   const Elf_Shdr *EShdr = getSection(Sec);
+  if (EShdr->sh_type == ELF::SHT_NOBITS)
+    return makeArrayRef((const uint8_t *)base(), 0);
   if (std::error_code EC =
           checkOffset(getMemoryBufferRef(),
                       (uintptr_t)base() + EShdr->sh_offset, EShdr->sh_size))


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