[llvm-readobj] - Do not fail to dump the object which has wrong type of .shstrtab.
Imagine we have object that has .shstrtab with type != SHT_STRTAB.
In this case, we fail to dump the object, though GNU readelf dumps it without
any issues and warnings.
This patch fixes that. It adds a code to ELFDumper.cpp which is based on the implementation of getSectionName from the ELF.h:
https://github.com/llvm-mirror/llvm/blob/master/include/llvm/Object/ELF.h#L608
https://github.com/llvm-mirror/llvm/blob/master/include/llvm/Object/ELF.h#L431
https://github.com/llvm-mirror/llvm/blob/master/include/llvm/Object/ELF.h#L539
The difference is that all non critical errors are ommitted what allows us to
improve the dumping on a tool side. Also, this opens a road for a follow-up that
should allow us to dump the section headers, but drop the section names in case if .shstrtab is completely absent and/or broken.
Differential revision: https://reviews.llvm.org/D63266
llvm-svn: 363371
diff --git a/llvm/tools/llvm-readobj/ELFDumper.cpp b/llvm/tools/llvm-readobj/ELFDumper.cpp
index 5efa351..e751e6d 100644
--- a/llvm/tools/llvm-readobj/ELFDumper.cpp
+++ b/llvm/tools/llvm-readobj/ELFDumper.cpp
@@ -3004,6 +3004,22 @@
}
template <class ELFT>
+static StringRef getSectionName(const typename ELFT::Shdr &Sec,
+ const ELFFile<ELFT> &Obj,
+ ArrayRef<typename ELFT::Shdr> Sections) {
+ uint32_t Index = Obj.getHeader()->e_shstrndx;
+ if (Index == ELF::SHN_XINDEX)
+ Index = Sections[0].sh_link;
+ if (!Index) // no section string table.
+ return "";
+ if (Index >= Sections.size())
+ reportError("invalid section index");
+ StringRef Data = toStringRef(unwrapOrError(
+ Obj.template getSectionContentsAsArray<uint8_t>(&Sections[Index])));
+ return unwrapOrError(Obj.getSectionName(&Sec, Data));
+}
+
+template <class ELFT>
void GNUStyle<ELFT>::printSectionHeaders(const ELFO *Obj) {
unsigned Bias = ELFT::Is64Bits ? 0 : 8;
ArrayRef<Elf_Shdr> Sections = unwrapOrError(Obj->sections());
@@ -3023,7 +3039,7 @@
size_t SectionIndex = 0;
for (const Elf_Shdr &Sec : Sections) {
Fields[0].Str = to_string(SectionIndex);
- Fields[1].Str = unwrapOrError(Obj->getSectionName(&Sec));
+ Fields[1].Str = getSectionName(Sec, *Obj, Sections);
Fields[2].Str =
getSectionTypeString(Obj->getHeader()->e_machine, Sec.sh_type);
Fields[3].Str =
@@ -4569,13 +4585,11 @@
ListScope SectionsD(W, "Sections");
int SectionIndex = -1;
- for (const Elf_Shdr &Sec : unwrapOrError(Obj->sections())) {
- ++SectionIndex;
-
- StringRef Name = unwrapOrError(Obj->getSectionName(&Sec));
-
+ ArrayRef<Elf_Shdr> Sections = unwrapOrError(Obj->sections());
+ for (const Elf_Shdr &Sec : Sections) {
+ StringRef Name = getSectionName(Sec, *Obj, Sections);
DictScope SectionD(W, "Section");
- W.printNumber("Index", SectionIndex);
+ W.printNumber("Index", ++SectionIndex);
W.printNumber("Name", Name, Sec.sh_name);
W.printHex(
"Type",