[llvm-mca] Add an error handler for error from parseCodeRegions

[mattd]

Summary

It's a bit tricky to add a test for the failing path right now, binary support will have an easier path to exercise the path here.

• Ran clang-format.

[mattd]

• Added context

[andreadb]

LGTM

llvm/trunk/tools/llvm-mca/llvm-mca.cpp

cl::desc(
         "Maximum number of cycles in the timeline view. Defaults to 80 cycles"),
     cl::cat(ViewOptions), cl::init(80));
 
 static cl::opt<bool>
     AssumeNoAlias("noalias",
                   cl::desc("If set, assume that loads and stores do not alias"),
                   cl::cat(ToolOptions), cl::init(true));
 
-static cl::opt<unsigned>
-    LoadQueueSize("lqueue",
+static cl::opt<unsigned> LoadQueueSize("lqueue",
                                        cl::desc("Size of the load queue"),
                                        cl::cat(ToolOptions), cl::init(0));
 
-static cl::opt<unsigned>
-    StoreQueueSize("squeue",
+static cl::opt<unsigned> StoreQueueSize("squeue",
                                         cl::desc("Size of the store queue"),
                                         cl::cat(ToolOptions), cl::init(0));
 
 static cl::opt<bool>
     PrintInstructionTables("instruction-tables",
                            cl::desc("Print instruction tables"),
                            cl::cat(ToolOptions), cl::init(false));
 
 static cl::opt<bool> PrintInstructionInfoView(
     "instruction-info",
if (STI->getSchedModel().InstrItineraries)
           << "cpu '" << MCPU << "' provides itineraries. However, "
           << "instruction itineraries are currently unsupported.\n";
     return 1;
   }
 
   // Parse the input and create CodeRegions that llvm-mca can analyze.
   mca::AsmCodeRegionGenerator CRG(*TheTarget, SrcMgr, Ctx, *MAI, *STI, *MCII);
   Expected<const mca::CodeRegions &> RegionsOrErr = CRG.parseCodeRegions();
-  if (auto Err = RegionsOrErr.takeError()) {
-    WithColor::error() << Err << "\n";
+  if (!RegionsOrErr) {
+    if (auto Err =
+            handleErrors(RegionsOrErr.takeError(), [](const StringError &Err) {
+              WithColor::error() << Err.getMessage() << '\n';
+            })) {
+      // Default case.
+      WithColor::error() << toString(std::move(Err)) << '\n';
+    }
     return 1;
   }
   const mca::CodeRegions &Regions = *RegionsOrErr;
   if (Regions.empty()) {
     WithColor::error() << "no assembly instructions found.\n";
     return 1;
   }