[llvm] a1e80ac - [Object] fixed invalid symbol handling in ELFObjectFile::getSymbolName

[Mircea Trofin via llvm-commits]

Author: Dayann D'almeida
Date: 2023-07-11T17:07:29-07:00
New Revision: a1e80acc6314066aeb55117127e1939d451bbc71

URL: https://github.com/llvm/llvm-project/commit/a1e80acc6314066aeb55117127e1939d451bbc71
DIFF: https://github.com/llvm/llvm-project/commit/a1e80acc6314066aeb55117127e1939d451bbc71.diff

LOG: [Object] fixed invalid symbol handling in ELFObjectFile::getSymbolName

Found a bug in ElfObjectFile.h that occurred when there was an invalid Symbol Name in an object file. This error affected the behavior of the Expected<> value and leading it to abort, rather than behave as normal. I found this as I was adding tests to llvm-cm, as prompted by @jhenderson.

Without this fix, upon encountering an invalid symbol and trying tot l get its name, the program states that
```Expected<T> must be checked before access or destruction```
 and aborts.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D154665

Added: 
    

Modified: 
    llvm/include/llvm/Object/ELFObjectFile.h
    llvm/test/tools/llvm-objdump/ELF/section-symbols.test

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/Object/ELFObjectFile.h b/llvm/include/llvm/Object/ELFObjectFile.h
index 275279597b140a..f3016cc141b0ed 100644
--- a/llvm/include/llvm/Object/ELFObjectFile.h
+++ b/llvm/include/llvm/Object/ELFObjectFile.h
@@ -530,10 +530,10 @@ Expected<StringRef> ELFObjectFile<ELFT>::getSymbolName(DataRefImpl Sym) const {
 
   // If the symbol name is empty use the section name.
   if ((*SymOrErr)->getType() == ELF::STT_SECTION) {
-    if (Expected<section_iterator> SecOrErr = getSymbolSection(Sym)) {
-      consumeError(Name.takeError());
+    Expected<section_iterator> SecOrErr = getSymbolSection(Sym);
+    if (SecOrErr)
       return (*SecOrErr)->getName();
-    }
+    return SecOrErr.takeError();
   }
   return Name;
 }

diff  --git a/llvm/test/tools/llvm-objdump/ELF/section-symbols.test b/llvm/test/tools/llvm-objdump/ELF/section-symbols.test
index 1dc416b38e8b79..ce7ea01a53aaaa 100644
--- a/llvm/test/tools/llvm-objdump/ELF/section-symbols.test
+++ b/llvm/test/tools/llvm-objdump/ELF/section-symbols.test
@@ -19,6 +19,11 @@
 # CHECK-NEXT: 00000003 R_X86_64_NONE            {{$}}
 # CHECK-NEXT: 00000004 R_X86_64_NONE            {{$}}
 
+## Test that we consume an error in ELFObjectFile<ELFT>::getSectionName when disassembling. 
+# RUN: llvm-objdump -d --syms %t1 2>&1 | \
+# RUN:   FileCheck %s -DFILE=%t1 --check-prefix=CHECK-DISAS
+# CHECK-DISAS: warning: '[[FILE]]': invalid section index: 67
+
 --- !ELF
 FileHeader:
   Class:   ELFCLASS32