[llvm-lib][llvm-dlltool] Fix handling of invalid ARM64EC function names (#116250)

This is a follow-up to #115567. Emit an error for invalid function
names, similar to MSVC's `lib.exe` behavior.

Returning an error from `writeImportLibrary` exposed bugs in error
handling by its callers, which have been addressed in this patch.

1 files changed, 9 insertions, 4 deletions

diff --git a/llvm/lib/ToolDrivers/llvm-lib/LibDriver.cpp b/llvm/lib/ToolDrivers/llvm-lib/LibDriver.cpp
index 07389a5..2e0841b 100644
--- a/llvm/lib/ToolDrivers/llvm-lib/LibDriver.cpp
+++ b/llvm/lib/ToolDrivers/llvm-lib/LibDriver.cpp
@@ -419,10 +419,15 @@ int llvm::libDriverMain(ArrayRef<const char *> ArgsArr) {
       OutputFile = std::move(NativeDef->OutputFile);
     }
 
-    return writeImportLibrary(OutputFile, OutputPath, Def->Exports, LibMachine,
-                              /*MinGW=*/false, NativeExports)
-               ? 1
-               : 0;
+    if (Error E =
+            writeImportLibrary(OutputFile, OutputPath, Def->Exports, LibMachine,
+                               /*MinGW=*/false, NativeExports)) {
+      handleAllErrors(std::move(E), [&](const ErrorInfoBase &EI) {
+        llvm::errs() << OutputPath << ": " << EI.message() << "\n";
+      });
+      return 1;
+    }
+    return 0;
   }
 
   // If no input files and not told otherwise, silently do nothing to match