Recommit r368812 "[llvm/Object] - Convert SectionRef::getName() to return Expected<>"

Changes: no changes. A fix for the clang code will be landed right on top.

Original commit message:

SectionRef::getName() returns std::error_code now.
Returning Expected<> instead has multiple benefits.

For example, it forces user to check the error returned.
Also Expected<> may keep a valuable string error message,
what is more useful than having a error code.
(Object\invalid.test was updated to show the new messages printed.)

This patch makes a change for all users to switch to Expected<> version.

Note: in a few places the error returned was ignored before my changes.
In such places I left them ignored. My intention was to convert the interface
used, and not to improve and/or the existent users in this patch.
(Though I think this is good idea for a follow-ups to revisit such places
and either remove consumeError calls or comment each of them to clarify why
it is OK to have them).

Differential revision: https://reviews.llvm.org/D66089

llvm-svn: 368826

6 files changed, 47 insertions, 24 deletions

diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
index f73d1c61edf..4b328624ccd 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
@@ -535,9 +535,10 @@ Error RuntimeDyldImpl::computeTotalAllocSize(const ObjectFile &Obj,
       bool IsCode = Section.isText();
       bool IsReadOnly = isReadOnlyData(Section);
 
-      StringRef Name;
-      if (auto EC = Section.getName(Name))
-        return errorCodeToError(EC);
+      Expected<StringRef> NameOrErr = Section.getName();
+      if (!NameOrErr)
+        return NameOrErr.takeError();
+      StringRef Name = *NameOrErr;
 
       uint64_t StubBufSize = computeSectionStubBufSize(Obj, Section);
 
@@ -777,9 +778,10 @@ RuntimeDyldImpl::emitSection(const ObjectFile &Obj,
   // anyway, so we should guarantee that the alignment is always at least 1.
   Alignment = std::max(1u, Alignment);
 
-  StringRef Name;
-  if (auto EC = Section.getName(Name))
-    return errorCodeToError(EC);
+  Expected<StringRef> NameOrErr = Section.getName();
+  if (!NameOrErr)
+    return NameOrErr.takeError();
+  StringRef Name = *NameOrErr;
 
   StubBufSize = computeSectionStubBufSize(Obj, Section);
 
diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
index 60041a45e2b..e3ace265f9c 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
@@ -160,9 +160,13 @@ createRTDyldELFObject(MemoryBufferRef Buffer, const ObjectFile &SourceObject,
   // Iterate over all sections in the object.
   auto SI = SourceObject.section_begin();
   for (const auto &Sec : Obj->sections()) {
-    StringRef SectionName;
-    Sec.getName(SectionName);
-    if (SectionName != "") {
+    Expected<StringRef> NameOrErr = Sec.getName();
+    if (!NameOrErr) {
+      consumeError(NameOrErr.takeError());
+      continue;
+    }
+
+    if (*NameOrErr != "") {
       DataRefImpl ShdrRef = Sec.getRawDataRefImpl();
       Elf_Shdr *shdr = const_cast<Elf_Shdr *>(
           reinterpret_cast<const Elf_Shdr *>(ShdrRef.p));
@@ -567,10 +571,11 @@ Error RuntimeDyldELF::findPPC64TOCSection(const ELFObjectFileBase &Obj,
 
   // The TOC consists of sections .got, .toc, .tocbss, .plt in that
   // order. The TOC starts where the first of these sections starts.
-  for (auto &Section: Obj.sections()) {
-    StringRef SectionName;
-    if (auto EC = Section.getName(SectionName))
-      return errorCodeToError(EC);
+  for (auto &Section : Obj.sections()) {
+    Expected<StringRef> NameOrErr = Section.getName();
+    if (!NameOrErr)
+      return NameOrErr.takeError();
+    StringRef SectionName = *NameOrErr;
 
     if (SectionName == ".got"
         || SectionName == ".toc"
@@ -605,9 +610,10 @@ Error RuntimeDyldELF::findOPDEntrySection(const ELFObjectFileBase &Obj,
     if (RelSecI == Obj.section_end())
       continue;
 
-    StringRef RelSectionName;
-    if (auto EC = RelSecI->getName(RelSectionName))
-      return errorCodeToError(EC);
+    Expected<StringRef> NameOrErr = RelSecI->getName();
+    if (!NameOrErr)
+      return NameOrErr.takeError();
+    StringRef RelSectionName = *NameOrErr;
 
     if (RelSectionName != ".opd")
       continue;
@@ -1879,8 +1885,14 @@ Error RuntimeDyldELF::finalizeLoad(const ObjectFile &Obj,
   ObjSectionToIDMap::iterator i, e;
   for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) {
     const SectionRef &Section = i->first;
+
     StringRef Name;
-    Section.getName(Name);
+    Expected<StringRef> NameOrErr = Section.getName();
+    if (NameOrErr)
+      Name = *NameOrErr;
+    else
+      consumeError(NameOrErr.takeError());
+
     if (Name == ".eh_frame") {
       UnregisteredEHFrameSections.push_back(i->second);
       break;
diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
index 202c3ca1c50..fbdfb8d5c3a 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldMachO.cpp
@@ -233,7 +233,10 @@ RuntimeDyldMachOCRTPBase<Impl>::finalizeLoad(const ObjectFile &Obj,
 
   for (const auto &Section : Obj.sections()) {
     StringRef Name;
-    Section.getName(Name);
+    if (Expected<StringRef> NameOrErr = Section.getName())
+      Name = *NameOrErr;
+    else
+      consumeError(NameOrErr.takeError());
 
     // Force emission of the __text, __eh_frame, and __gcc_except_tab sections
     // if they're present. Otherwise call down to the impl to handle other
diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldCOFFX86_64.h b/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldCOFFX86_64.h
index d2d74534cf9..dc4af08583d 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldCOFFX86_64.h
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldCOFFX86_64.h
@@ -284,14 +284,14 @@ public:
     // Look for and record the EH frame section IDs.
     for (const auto &SectionPair : SectionMap) {
       const object::SectionRef &Section = SectionPair.first;
-      StringRef Name;
-      if (auto EC = Section.getName(Name))
-        return errorCodeToError(EC);
+      Expected<StringRef> NameOrErr = Section.getName();
+      if (!NameOrErr)
+        return NameOrErr.takeError();
 
       // Note unwind info is stored in .pdata but often points to .xdata
       // with an IMAGE_REL_AMD64_ADDR32NB relocation. Using a memory manager
       // that keeps sections ordered in relation to __ImageBase is necessary.
-      if (Name == ".pdata")
+      if ((*NameOrErr) == ".pdata")
         UnregisteredEHFrameSections.push_back(SectionPair.second);
     }
     return Error::success();
diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOARM.h b/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOARM.h
index 3bec8b979f7..a76958a9e2c 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOARM.h
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOARM.h
@@ -289,7 +289,10 @@ public:
   Error finalizeSection(const ObjectFile &Obj, unsigned SectionID,
                        const SectionRef &Section) {
     StringRef Name;
-    Section.getName(Name);
+    if (Expected<StringRef> NameOrErr = Section.getName())
+      Name = *NameOrErr;
+    else
+      consumeError(NameOrErr.takeError());
 
     if (Name == "__nl_symbol_ptr")
       return populateIndirectSymbolPointersSection(cast<MachOObjectFile>(Obj),
diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOI386.h b/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOI386.h
index f0de27ba14b..523deb29b72 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOI386.h
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/Targets/RuntimeDyldMachOI386.h
@@ -128,7 +128,10 @@ public:
   Error finalizeSection(const ObjectFile &Obj, unsigned SectionID,
                        const SectionRef &Section) {
     StringRef Name;
-    Section.getName(Name);
+    if (Expected<StringRef> NameOrErr = Section.getName())
+      Name = *NameOrErr;
+    else
+      consumeError(NameOrErr.takeError());
 
     if (Name == "__jump_table")
       return populateJumpTable(cast<MachOObjectFile>(Obj), Section, SectionID);