Thread Expected<...> up from libObject’s getName() 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
string index is past the end of the string table.  The existing test case in test/Object/macho-invalid.test
for macho-invalid-symbol-name-past-eof now reports the error with the message indicating
that a symbol at a specific index has a bad sting index and that bad string 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.  There is some
code for this that could be factored into a routine but I would like to leave that for
the code owners post-commit to do as they want for handling an llvm::Error.  An
example of how this could be done is shown in the diff in
lib/ExecutionEngine/RuntimeDyld/RuntimeDyldImpl.h which had a Check() routine
already for std::error_code so I added one like it for llvm::Error .

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.

Note there fixes needed to lld that goes along with this that I will commit right after this.
So expect lld not to built after this commit and before the next one.

llvm-svn: 266919

1 files changed, 5 insertions, 5 deletions

diff --git a/llvm/tools/llvm-readobj/COFFDumper.cpp b/llvm/tools/llvm-readobj/COFFDumper.cpp
index da869817f86..56c83c2046d 100644
--- a/llvm/tools/llvm-readobj/COFFDumper.cpp
+++ b/llvm/tools/llvm-readobj/COFFDumper.cpp
@@ -187,9 +187,9 @@ std::error_code COFFDumper::resolveSymbolName(const coff_section *Section,
   SymbolRef Symbol;
   if (std::error_code EC = resolveSymbol(Section, Offset, Symbol))
     return EC;
-  ErrorOr<StringRef> NameOrErr = Symbol.getName();
-  if (std::error_code EC = NameOrErr.getError())
-    return EC;
+  Expected<StringRef> NameOrErr = Symbol.getName();
+  if (!NameOrErr)
+    return errorToErrorCode(NameOrErr.takeError());
   Name = *NameOrErr;
   return std::error_code();
 }
@@ -2605,8 +2605,8 @@ void COFFDumper::printRelocation(const SectionRef &Section,
   Reloc.getTypeName(RelocName);
   symbol_iterator Symbol = Reloc.getSymbol();
   if (Symbol != Obj->symbol_end()) {
-    ErrorOr<StringRef> SymbolNameOrErr = Symbol->getName();
-    error(SymbolNameOrErr.getError());
+    Expected<StringRef> SymbolNameOrErr = Symbol->getName();
+    error(errorToErrorCode(SymbolNameOrErr.takeError()));
     SymbolName = *SymbolNameOrErr;
   }