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, 20 insertions, 14 deletions

diff --git a/llvm/tools/llvm-objdump/llvm-objdump.cpp b/llvm/tools/llvm-objdump/llvm-objdump.cpp
index 6eab69c1b2e..c99e4b0e205 100644
--- a/llvm/tools/llvm-objdump/llvm-objdump.cpp
+++ b/llvm/tools/llvm-objdump/llvm-objdump.cpp
@@ -494,9 +494,9 @@ static std::error_code getRelocationValueString(const ELFObjectFile<ELFT> *Obj,
       return EC;
     Target = *SecName;
   } else {
-    ErrorOr<StringRef> SymName = symb->getName(StrTab);
+    Expected<StringRef> SymName = symb->getName(StrTab);
     if (!SymName)
-      return SymName.getError();
+      return errorToErrorCode(SymName.takeError());
     Target = *SymName;
   }
   switch (EF.getHeader()->e_machine) {
@@ -586,9 +586,9 @@ static std::error_code getRelocationValueString(const COFFObjectFile *Obj,
                                                 const RelocationRef &Rel,
                                                 SmallVectorImpl<char> &Result) {
   symbol_iterator SymI = Rel.getSymbol();
-  ErrorOr<StringRef> SymNameOrErr = SymI->getName();
-  if (std::error_code EC = SymNameOrErr.getError())
-    return EC;
+  Expected<StringRef> SymNameOrErr = SymI->getName();
+  if (!SymNameOrErr)
+    return errorToErrorCode(SymNameOrErr.takeError());
   StringRef SymName = *SymNameOrErr;
   Result.append(SymName.begin(), SymName.end());
   return std::error_code();
@@ -613,9 +613,14 @@ static void printRelocationTargetName(const MachOObjectFile *O,
         report_fatal_error(ec.message());
       if (*Addr != Val)
         continue;
-      ErrorOr<StringRef> Name = Symbol.getName();
-      if (std::error_code EC = Name.getError())
-        report_fatal_error(EC.message());
+      Expected<StringRef> Name = Symbol.getName();
+      if (!Name) {
+        std::string Buf;
+        raw_string_ostream OS(Buf);
+        logAllUnhandledErrors(Name.takeError(), OS, "");
+        OS.flush();
+        report_fatal_error(Buf);
+      }
       fmt << *Name;
       return;
     }
@@ -646,8 +651,8 @@ static void printRelocationTargetName(const MachOObjectFile *O,
   if (isExtern) {
     symbol_iterator SI = O->symbol_begin();
     advance(SI, Val);
-    ErrorOr<StringRef> SOrErr = SI->getName();
-    error(SOrErr.getError());
+    Expected<StringRef> SOrErr = SI->getName();
+    error(errorToErrorCode(SOrErr.takeError()));
     S = *SOrErr;
   } else {
     section_iterator SI = O->section_begin();
@@ -952,8 +957,8 @@ static void DisassembleObject(const ObjectFile *Obj, bool InlineRelocs) {
     error(AddressOrErr.getError());
     uint64_t Address = *AddressOrErr;
 
-    ErrorOr<StringRef> Name = Symbol.getName();
-    error(Name.getError());
+    Expected<StringRef> Name = Symbol.getName();
+    error(errorToErrorCode(Name.takeError()));
     if (Name->empty())
       continue;
 
@@ -1358,8 +1363,9 @@ void llvm::PrintSymbolTable(const ObjectFile *o) {
     if (Type == SymbolRef::ST_Debug && Section != o->section_end()) {
       Section->getName(Name);
     } else {
-      ErrorOr<StringRef> NameOrErr = Symbol.getName();
-      error(NameOrErr.getError());
+      Expected<StringRef> NameOrErr = Symbol.getName();
+      if (!NameOrErr)
+        report_error(o->getFileName(), NameOrErr.takeError());
       Name = *NameOrErr;
     }