From 3f6881efa54ecb1afdf2fc1481e91e921ed7f9fc Mon Sep 17 00:00:00 2001
From: "Michael J. Spencer" <bigcheesegs@gmail.com>
Date: Tue, 21 Jul 2015 21:40:33 +0000
Subject: [PATCH] [Object][ELF] Handle files with no section header string
 table.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242839 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/Object/ELF.h                     |  20 ++++++++++++------
 .../no-section-header-string-table.elf-x86-64 | Bin 0 -> 1024 bytes
 .../no-section-header-string-table.test       |  10 +++++++++
 3 files changed, 23 insertions(+), 7 deletions(-)
 create mode 100644 test/Object/Inputs/no-section-header-string-table.elf-x86-64
 create mode 100644 test/Object/no-section-header-string-table.test

diff --git a/include/llvm/Object/ELF.h b/include/llvm/Object/ELF.h
index 775403c23df..ec7e59f9bc5 100644
--- a/include/llvm/Object/ELF.h
+++ b/include/llvm/Object/ELF.h
@@ -629,14 +629,18 @@ ELFFile<ELFT>::ELFFile(StringRef Object, std::error_code &EC)
   }
 
   // Get string table sections.
-  ErrorOr<const Elf_Shdr *> StrTabSecOrErr = getSection(getStringTableIndex());
-  if ((EC = StrTabSecOrErr.getError()))
-    return;
+  uintX_t StringTableIndex = getStringTableIndex();
+  if (StringTableIndex) {
+    ErrorOr<const Elf_Shdr *> StrTabSecOrErr =
+        getSection(getStringTableIndex());
+    if ((EC = StrTabSecOrErr.getError()))
+      return;
 
-  ErrorOr<StringRef> SymtabOrErr = getStringTable(*StrTabSecOrErr);
-  if ((EC = SymtabOrErr.getError()))
-    return;
-  DotShstrtab = *SymtabOrErr;
+    ErrorOr<StringRef> SymtabOrErr = getStringTable(*StrTabSecOrErr);
+    if ((EC = SymtabOrErr.getError()))
+      return;
+    DotShstrtab = *SymtabOrErr;
+  }
 
   // Build symbol name side-mapping if there is one.
   if (SymbolTableSectionHeaderIndex) {
@@ -746,6 +750,8 @@ template <class ELFT>
 ErrorOr<StringRef>
 ELFFile<ELFT>::getSectionName(const Elf_Shdr *Section) const {
   uint32_t Offset = Section->sh_name;
+  if (Offset == 0)
+    return StringRef();
   if (Offset >= DotShstrtab.size())
     return object_error::parse_failed;
   return StringRef(DotShstrtab.data() + Offset);
diff --git a/test/Object/Inputs/no-section-header-string-table.elf-x86-64 b/test/Object/Inputs/no-section-header-string-table.elf-x86-64
new file mode 100644
index 0000000000000000000000000000000000000000..9024ad9b75739802e8c828d6f0089e0cf98b02e9
GIT binary patch
literal 1024
zcmbVLu}T9$5S>e+21JlFDp)9pT^6H_m0Y3mK+!_PdXuc=^l~e=8;O;HlzxsMU_ilN
zv9Pfh;?CV{++1Sg!0nrP^JZ^nZ|?Evv|jMMB9M7-0G<t8Ec^z3>iSSN7z{qk?}u9@
zq+W3Oz-4Ec!jnk^gSYZ)AfiZaT*)MAZDJl^DFawEIDWbDE5zgL7R>WK%52Ty=N+Et
zDZm~|@HLuB7@|14L&G~wI)%lF6K07O0~KeVZPH_V%jCPT{s#{_3GYK5Rb}HwG<8)A
zrI~^b4`aCNY6TavBhGbOB=v6G)S-+4m=-+^ERij)Ia4~Ru^O;gYQc`rE~`rO=B-JK
zh?7!1bTn@ON;7Pe=brHYKHfEc6W4qS?7i6Bth>Sb-JJfKVml|c9<_OMxjjm%yoh2~
zYbELMQm{|hBMb=V3}P+LJlbjo>FQ2RpZH-8@qTcRS@rJx`*grQq3wsZb0*F*lmCyR
Px@W?ZUs>uAJ!XFZ8^cx*

literal 0
HcmV?d00001

diff --git a/test/Object/no-section-header-string-table.test b/test/Object/no-section-header-string-table.test
new file mode 100644
index 00000000000..1f449328cab
--- /dev/null
+++ b/test/Object/no-section-header-string-table.test
@@ -0,0 +1,10 @@
+RUN: llvm-readobj %p/Inputs/no-section-header-string-table.elf-x86-64 --sections \
+RUN:   | FileCheck %s
+
+CHECK:    Type: SHT_PROGBITS (0x1)
+CHECK:    Type: SHT_PROGBITS (0x1)
+CHECK:    Type: SHT_PROGBITS (0x1)
+CHECK:    Type: SHT_RELA (0x4)
+CHECK:    Type: SHT_SYMTAB (0x2)
+CHECK:    Type: SHT_STRTAB (0x3)
+CHECK:    Type: SHT_STRTAB (0x3)