[llvm/Object] - Make ELFObjectFile::getRelocatedSection return Expected<section_iterator>

It returns just a section_iterator currently and have a report_fatal_error call inside.
This change adds a way to return errors and handle them on caller sides.

The patch also changes/improves current users and adds test cases.

Differential revision: https://reviews.llvm.org/D69167

llvm-svn: 375408

3 files changed, 34 insertions, 7 deletions

diff --git a/llvm/tools/llvm-cxxdump/llvm-cxxdump.cpp b/llvm/tools/llvm-cxxdump/llvm-cxxdump.cpp
index 83331265578..03e1bab9417 100644
--- a/llvm/tools/llvm-cxxdump/llvm-cxxdump.cpp
+++ b/llvm/tools/llvm-cxxdump/llvm-cxxdump.cpp
@@ -174,7 +174,11 @@ static void dumpCXXData(const ObjectFile *Obj) {
 
   SectionRelocMap.clear();
   for (const SectionRef &Section : Obj->sections()) {
-    section_iterator Sec2 = Section.getRelocatedSection();
+    Expected<section_iterator> ErrOrSec = Section.getRelocatedSection();
+    if (!ErrOrSec)
+      error(ErrOrSec.takeError());
+
+    section_iterator Sec2 = *ErrOrSec;
     if (Sec2 != Obj->section_end())
       SectionRelocMap[*Sec2].push_back(Section);
   }
diff --git a/llvm/tools/llvm-objdump/llvm-objdump.cpp b/llvm/tools/llvm-objdump/llvm-objdump.cpp
index c5381d53717..34a44b3b7fa 100644
--- a/llvm/tools/llvm-objdump/llvm-objdump.cpp
+++ b/llvm/tools/llvm-objdump/llvm-objdump.cpp
@@ -993,8 +993,17 @@ static size_t countSkippableZeroBytes(ArrayRef<uint8_t> Buf) {
 static std::map<SectionRef, std::vector<RelocationRef>>
 getRelocsMap(object::ObjectFile const &Obj) {
   std::map<SectionRef, std::vector<RelocationRef>> Ret;
+  uint64_t I = (uint64_t)-1;
   for (SectionRef Sec : Obj.sections()) {
-    section_iterator Relocated = Sec.getRelocatedSection();
+    ++I;
+    Expected<section_iterator> RelocatedOrErr = Sec.getRelocatedSection();
+    if (!RelocatedOrErr)
+      reportError(Obj.getFileName(),
+                  "section (" + Twine(I) +
+                      "): failed to get a relocated section: " +
+                      toString(RelocatedOrErr.takeError()));
+
+    section_iterator Relocated = *RelocatedOrErr;
     if (Relocated == Obj.section_end() || !checkSectionFilter(*Relocated).Keep)
       continue;
     std::vector<RelocationRef> &V = Ret[*Relocated];
@@ -1606,11 +1615,17 @@ void printRelocations(const ObjectFile *Obj) {
   // sections. Usually, there is an only one relocation section for
   // each relocated section.
   MapVector<SectionRef, std::vector<SectionRef>> SecToRelSec;
-  for (const SectionRef &Section : ToolSectionFilter(*Obj)) {
+  uint64_t Ndx;
+  for (const SectionRef &Section : ToolSectionFilter(*Obj, &Ndx)) {
     if (Section.relocation_begin() == Section.relocation_end())
       continue;
-    const SectionRef TargetSec = *Section.getRelocatedSection();
-    SecToRelSec[TargetSec].push_back(Section);
+    Expected<section_iterator> SecOrErr = Section.getRelocatedSection();
+    if (!SecOrErr)
+      reportError(Obj->getFileName(),
+                  "section (" + Twine(Ndx) +
+                      "): unable to get a relocation target: " +
+                      toString(SecOrErr.takeError()));
+    SecToRelSec[**SecOrErr].push_back(Section);
   }
 
   for (std::pair<SectionRef, std::vector<SectionRef>> &P : SecToRelSec) {
diff --git a/llvm/tools/llvm-readobj/ELFDumper.cpp b/llvm/tools/llvm-readobj/ELFDumper.cpp
index 7e140933393..57144882c4b 100644
--- a/llvm/tools/llvm-readobj/ELFDumper.cpp
+++ b/llvm/tools/llvm-readobj/ELFDumper.cpp
@@ -4894,8 +4894,16 @@ void DumpStyle<ELFT>::printRelocatableStackSizes(
     if (SectionType != ELF::SHT_RELA && SectionType != ELF::SHT_REL)
       continue;
 
-    SectionRef Contents = *Sec.getRelocatedSection();
-    const Elf_Shdr *ContentsSec = Obj->getSection(Contents.getRawDataRefImpl());
+    Expected<section_iterator> RelSecOrErr = Sec.getRelocatedSection();
+    if (!RelSecOrErr)
+      reportError(createStringError(object_error::parse_failed,
+                                    "%s: failed to get a relocated section: %s",
+                                    SectionName.data(),
+                                    toString(RelSecOrErr.takeError()).c_str()),
+                  Obj->getFileName());
+
+    const Elf_Shdr *ContentsSec =
+        Obj->getSection((*RelSecOrErr)->getRawDataRefImpl());
     Expected<StringRef> ContentsSectionNameOrErr =
         EF->getSectionName(ContentsSec);
     if (!ContentsSectionNameOrErr) {