Thread Expected<...> up from libObject’s getType() for symbols to allow llvm-objdump to produce a good error message.

Produce another specific error message for a malformed Mach-O file when a symbol’s
section index is more than the number of sections.  The existing test case in test/Object/macho-invalid.test
for macho-invalid-section-index-getSectionRawName now reports the error with the message indicating
that a symbol at a specific index has a bad section index and that bad section index value.

Again converting interfaces to Expected<> from ErrorOr<> does involve
touching a number of places. Where the existing code reported the error with a
string message or an error code it was converted to do the same.

Also there some were bugs in the existing code that did not deal with the
old ErrorOr<> return values.  So now with Expected<> since they must be
checked and the error handled, I added a TODO and a comment:
"// TODO: Actually report errors helpfully" and a call something like
consumeError(NameOrErr.takeError()) so the buggy code will not crash
since needed to deal with the Error.

llvm-svn: 268298

1 files changed, 11 insertions, 1 deletions

diff --git a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
index 6aa4675630f..d3b5e736c48 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
@@ -763,7 +763,17 @@ DWARFContextInMemory::DWARFContextInMemory(const object::ObjectFile &Obj,
           }
           SymAddr = *SymAddrOrErr;
           // Also remember what section this symbol is in for later
-          RSec = *Sym->getSection();
+          auto SectOrErr = Sym->getSection();
+          if (!SectOrErr) {
+            std::string Buf;
+            raw_string_ostream OS(Buf);
+            logAllUnhandledErrors(SectOrErr.takeError(), OS, "");
+            OS.flush();
+            errs() << "error: failed to get symbol section: "
+                   << Buf << '\n';
+            continue;
+          }
+          RSec = *SectOrErr;
         } else if (auto *MObj = dyn_cast<MachOObjectFile>(&Obj)) {
           // MachO also has relocations that point to sections and
           // scattered relocations.