[llvm] [DTLTO] [LLVM] Initial DTLTO cache implementation (PR #156433)

[Katya Romanova via llvm-commits]

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@@ -281,6 +281,7 @@ struct Config {
   LLVM_ABI Error addSaveTemps(std::string OutputFileName,
                               bool UseInputModulePath = false,
                               const DenseSet<StringRef> &SaveTempsArgs = {});
+  mutable uint8_t Dtlto = 0;
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romanova-ekaterina wrote:

Changed its type to bool and added a comment. 

This flag is used as one of parameters to calculate cache entries and to ensure that in-process cache and out-of-process (DTLTO) cache are distinguished. 

It is passed as a part of const Config &Conf to a function that computes LTO Cache Key (computeLTOCacheKey). 

Another option: instead of adding Dtlto to Config class, we could simply change the signature of computeLTOCacheKey and add Dtlto flag as an additional parameter to this function. 

Do you think it will be better?

https://github.com/llvm/llvm-project/pull/156433