[llvm] [llvm-remarkutil] Auto-detect serializer format based on file extension (PR #160545)

[Jon Roelofs via llvm-commits]

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@@ -46,12 +46,8 @@ static Error tryFilter() {
     return MaybeParser.takeError();
   auto &Parser = **MaybeParser;
 
-  Format SerializerFormat = OutputFormat;
-  if (SerializerFormat == Format::Auto) {
-    SerializerFormat = Parser.ParserFormat;
-    if (OutputFileName.empty() || OutputFileName == "-")
-      SerializerFormat = Format::YAML;
-  }
+  Format SerializerFormat =
+      getSerializerFormat(OutputFileName, OutputFormat, Parser.ParserFormat);
 
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jroelofs wrote:

WDYT about making the default be bitstream (unless the input was yaml), and then adding a warning/error message here if the output is a tty, kind of like `opt` does when you try to write bitcode to the terminal? I think our "north star" should be to converge on "bitstream for everything except LIT tests".

https://github.com/llvm/llvm-project/pull/160545