[PATCH] D154130: [lit][clang] Avoid realpath on Windows due to MAX_PATH limitations

[Tristan Labelle via Phabricator via cfe-commits]

MrTrillian marked an inline comment as done.
MrTrillian added inline comments.


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Comment at: clang/test/Lexer/case-insensitive-include-win.c:5-9
+// Note: We must use the real path here, because the logic to detect case
+// mismatch relies on resolving the real path and checking that casing differs.
+// If we use %t and we are on a substitute drive S: mapping to C:\subst,
+// then we will compare "S:\test.dir\FOO.h" to "C:\subst\test.dir\foo.h"
+// and avoid emitting the diagnostic because the structure is different.
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tahonermann wrote:
> Hmm, is it really desirable or necessary that the case mismatch logic resolve substituted drives? I wouldn't think so. This seems like another case where our common canonicalization would be desired.
I think it is necessary as I don't see how else we can retrieve the original casing of the file path. Merely making the path absolute would not do that. Searching for solutions on the internet finds ideas that are worse like converting to a short path then back to a long path or rebuilding the path one component at a time with a series directory listing requests.


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https://reviews.llvm.org/D154130