[PATCH] D100489: [llvm-readobj] Fix dumping dynamic relative relocations for SHT_REL

[Alexander Richardson via Phabricator via llvm-commits]

arichardson updated this revision to Diff 337676.
arichardson marked an inline comment as done.
arichardson added a comment.

Improve test


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D100489/new/

https://reviews.llvm.org/D100489

Files:
  llvm/test/tools/llvm-objdump/X86/elf-dynamic-relocs-rel.test
  llvm/tools/llvm-objdump/ELFDump.cpp


Index: llvm/tools/llvm-objdump/ELFDump.cpp
===================================================================
--- llvm/tools/llvm-objdump/ELFDump.cpp
+++ llvm/tools/llvm-objdump/ELFDump.cpp
@@ -74,7 +74,10 @@
     const typename ELFT::Rela *ERela = Obj->getRela(Rel);
     Addend = ERela->r_addend;
     Undef = ERela->getSymbol(false) == 0;
-  } else if ((*SecOrErr)->sh_type != ELF::SHT_REL) {
+  } else if ((*SecOrErr)->sh_type == ELF::SHT_REL) {
+    const typename ELFT::Rel *ERel = Obj->getRel(Rel);
+    Undef = ERel->getSymbol(false) == 0;
+  } else {
     return make_error<BinaryError>();
   }
 
Index: llvm/test/tools/llvm-objdump/X86/elf-dynamic-relocs-rel.test
===================================================================
--- /dev/null
+++ llvm/test/tools/llvm-objdump/X86/elf-dynamic-relocs-rel.test
@@ -0,0 +1,67 @@
+## Show that llvm-objdump can dump dynamic relocations for Elf_Rel relocations
+## Previously printing the R_386_RELATIVE relocations would trigger
+## error: can't read an entry at 0x40: it goes past the end of the section (0x40)
+
+# RUN: yaml2obj %s -o %t
+# RUN: llvm-readelf --section-headers --section-mapping --program-headers -r %t
+# RUN: llvm-objdump --dynamic-reloc %t | FileCheck %s
+# RUN: llvm-objdump -R %t | FileCheck %s
+
+# CHECK:      file format elf32-i386
+# CHECK-LABEL: DYNAMIC RELOCATION RECORDS
+# CHECK-NEXT: 00000030 R_386_RELATIVE *ABS*
+# CHECK-NEXT: 00000010 R_386_NONE foo
+# CHECK-EMPTY:
+
+--- !ELF
+FileHeader:
+  Class:           ELFCLASS32
+  Data:            ELFDATA2LSB
+  Type:            ET_DYN
+  Machine:         EM_386
+ProgramHeaders:
+  - Type:     PT_LOAD
+    FirstSec: .rel.dyn
+    LastSec:  .data
+  - Type:     PT_DYNAMIC
+    VAddr:    0x10
+    FirstSec: .dynamic
+    LastSec:  .dynamic
+Sections:
+  - Name:            .rel.dyn
+    Type:            SHT_REL
+    Flags:           [ SHF_ALLOC ]
+    AddressAlign:    0x4
+    Relocations:
+      - Offset:          0x30
+        Type:            R_386_RELATIVE
+      - Offset:          0x10
+        Symbol:          foo
+        Type:            R_386_NONE
+  - Name:            .dynamic
+    Type:            SHT_DYNAMIC
+    Flags:           [ SHF_ALLOC ]
+    Link:            .dynstr
+    AddressAlign:    0x4
+    Entries:
+      - Tag:             DT_REL
+        Value:           0x0
+      - Tag:             DT_RELSZ
+        Value:           0x10
+      - Tag:             DT_RELENT
+        Value:           0x8
+      - Tag:             DT_RELCOUNT
+        Value:           0x1
+      - Tag:             DT_NULL
+        Value:           0x0
+  - Name:            .data
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_WRITE, SHF_ALLOC ]
+    AddressAlign:    0x4
+    Content:         '80110000'
+Symbols:
+  - Name:    foo
+    Section: .data
+DynamicSymbols:
+  - Name:    foo
+    Section: .data


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