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, 32 insertions, 12 deletions

diff --git a/llvm/tools/llvm-readobj/ARMWinEHPrinter.cpp b/llvm/tools/llvm-readobj/ARMWinEHPrinter.cpp
index 0f74a998707..8d00c90b3c1 100644
--- a/llvm/tools/llvm-readobj/ARMWinEHPrinter.cpp
+++ b/llvm/tools/llvm-readobj/ARMWinEHPrinter.cpp
@@ -570,9 +570,14 @@ bool Decoder::dumpXDataRecord(const COFFObjectFile &COFF,
     if (!Symbol)
       Symbol = getSymbol(COFF, Address, /*FunctionOnly=*/true);
 
-    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;
+      llvm::raw_string_ostream OS(Buf);
+      logAllUnhandledErrors(Name.takeError(), OS, "");
+      OS.flush();
+      report_fatal_error(Buf);
+    }
 
     ListScope EHS(SW, "ExceptionHandler");
     SW.printString("Routine", formatSymbol(*Name, Address));
@@ -604,9 +609,14 @@ bool Decoder::dumpUnpackedEntry(const COFFObjectFile &COFF,
   StringRef FunctionName;
   uint64_t FunctionAddress;
   if (Function) {
-    ErrorOr<StringRef> FunctionNameOrErr = Function->getName();
-    if (std::error_code EC = FunctionNameOrErr.getError())
-      report_fatal_error(EC.message());
+    Expected<StringRef> FunctionNameOrErr = Function->getName();
+    if (!FunctionNameOrErr) {
+      std::string Buf;
+      llvm::raw_string_ostream OS(Buf);
+      logAllUnhandledErrors(FunctionNameOrErr.takeError(), OS, "");
+      OS.flush();
+      report_fatal_error(Buf);
+    }
     FunctionName = *FunctionNameOrErr;
     ErrorOr<uint64_t> FunctionAddressOrErr = Function->getAddress();
     if (std::error_code EC = FunctionAddressOrErr.getError())
@@ -622,9 +632,14 @@ bool Decoder::dumpUnpackedEntry(const COFFObjectFile &COFF,
   SW.printString("Function", formatSymbol(FunctionName, FunctionAddress));
 
   if (XDataRecord) {
-    ErrorOr<StringRef> Name = XDataRecord->getName();
-    if (std::error_code EC = Name.getError())
-      report_fatal_error(EC.message());
+    Expected<StringRef> Name = XDataRecord->getName();
+    if (!Name) {
+      std::string Buf;
+      llvm::raw_string_ostream OS(Buf);
+      logAllUnhandledErrors(Name.takeError(), OS, "");
+      OS.flush();
+      report_fatal_error(Buf);
+    }
 
     ErrorOr<uint64_t> AddressOrErr = XDataRecord->getAddress();
     if (std::error_code EC = AddressOrErr.getError())
@@ -671,9 +686,14 @@ bool Decoder::dumpPackedEntry(const object::COFFObjectFile &COFF,
   StringRef FunctionName;
   uint64_t FunctionAddress;
   if (Function) {
-    ErrorOr<StringRef> FunctionNameOrErr = Function->getName();
-    if (std::error_code EC = FunctionNameOrErr.getError())
-      report_fatal_error(EC.message());
+    Expected<StringRef> FunctionNameOrErr = Function->getName();
+    if (!FunctionNameOrErr) {
+      std::string Buf;
+      llvm::raw_string_ostream OS(Buf);
+      logAllUnhandledErrors(FunctionNameOrErr.takeError(), OS, "");
+      OS.flush();
+      report_fatal_error(Buf);
+    }
     FunctionName = *FunctionNameOrErr;
     ErrorOr<uint64_t> FunctionAddressOrErr = Function->getAddress();
     FunctionAddress = *FunctionAddressOrErr;