[llvm] Normalize file path to fix problems with different folder separators. (PR #215225)

[via llvm-commits]

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@@ -85,22 +85,22 @@ static std::string applySubstitutePaths(StringRef FileName) {
   if (SubstitutePaths.empty())
     return FileName.str();
 
+  // FileName is normalized by the caller, so the components split out of it are
+  // normalized too. Only the rules given on the command line still need it.
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VladimirMedic wrote:

 It could be discussed if normalization of the command line arguments would be worthwhile, but it does not directly affect the bugs described. The comment just clarifies why the normalization calls has been removed for some variables and not for others.

https://github.com/llvm/llvm-project/pull/215225