[PATCH] D58498: [obj2yaml] - Do not miss section index for SHN_ABS and SHN_COMMON symbols.

[George Rimar via Phabricator via llvm-commits]

grimar created this revision.
grimar added a reviewer: jhenderson.
Herald added a subscriber: arphaman.

This fixes https://bugs.llvm.org/show_bug.cgi?id=40786 
("obj2yaml symbol output missing section index for SHN_ABS and SHN_COMMON symbols")

Since SHN_ABS and SHN_COMMON symbols are special, we should preserve
the st_shndx for them. The patch does this.


https://reviews.llvm.org/D58498

Files:
  test/tools/yaml2obj/abs-common-symbols.yaml
  tools/obj2yaml/elf2yaml.cpp


Index: tools/obj2yaml/elf2yaml.cpp
===================================================================
--- tools/obj2yaml/elf2yaml.cpp
+++ tools/obj2yaml/elf2yaml.cpp
@@ -276,6 +276,11 @@
     return errorToErrorCode(SymbolNameOrErr.takeError());
   S.Name = SymbolNameOrErr.get();
 
+  if (Sym->st_shndx == ELF::SHN_ABS || Sym->st_shndx == ELF::SHN_COMMON) {
+    S.Index = (ELFYAML::ELF_SHN)Sym->st_shndx;
+    return obj2yaml_error::success;
+  }
+
   auto ShdrOrErr = Obj.getSection(Sym, SymTab, ShndxTable);
   if (!ShdrOrErr)
     return errorToErrorCode(ShdrOrErr.takeError());
Index: test/tools/yaml2obj/abs-common-symbols.yaml
===================================================================
--- /dev/null
+++ test/tools/yaml2obj/abs-common-symbols.yaml
@@ -0,0 +1,41 @@
+# RUN: yaml2obj %s > %t
+# RUN: obj2yaml %t | FileCheck %s
+
+# CHECK:      Symbols:
+# CHECK-NEXT:   Global:
+# CHECK-NEXT:     - Name:    absolute1
+# CHECK-NEXT:       Index:   SHN_ABS
+# CHECK-NEXT:       Value:   0x0000000000001234
+# CHECK-NEXT:     - Name:    absolute2
+# CHECK-NEXT:       Index:   SHN_ABS
+# CHECK-NEXT:       Value:   0x0000000000004321
+# CHECK-NEXT:     - Name:    common1
+# CHECK-NEXT:       Index:   SHN_COMMON
+# CHECK-NEXT:     - Name:    common2
+# CHECK-NEXT:       Index:   SHN_COMMON
+# CHECK-NEXT:     - Name:    valid_index
+# CHECK-NEXT:       Section: .text
+
+!ELF
+FileHeader:
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  Type:            ET_EXEC
+  Machine:         EM_X86_64
+Sections:
+  - Name: .text
+    Type: SHT_PROGBITS
+Symbols:
+  Global:
+    - Name:     absolute1
+      Index:    SHN_ABS
+      Value:    0x1234
+    - Name:     absolute2
+      Index:    0xfff1
+      Value:    0x4321
+    - Name:     common1
+      Index:    SHN_COMMON
+    - Name:     common2
+      Index:    0xfff2
+    - Name:     valid_index
+      Index:    0x1


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