[PATCH] D23816: Add support for -fdiagnostics-abs-path: printing absolute paths in diagnostics

[Hans Wennborg via cfe-commits]

hans added inline comments.

================
Comment at: lib/Frontend/TextDiagnostic.cpp:770-777
@@ +769,10 @@
+  if (DiagOpts->AbsolutePath) {
+    const DirectoryEntry *Dir = SM.getFileManager().getDirectory(
+        llvm::sys::path::parent_path(Filename));
+    if (Dir) {
+      StringRef DirName = SM.getFileManager().getCanonicalName(Dir);
+      llvm::sys::path::append(AbsoluteFilename, DirName,
+                              llvm::sys::path::filename(Filename));
+      Filename = StringRef(AbsoluteFilename.data(), AbsoluteFilename.size());
+    }
+  }
----------------
rsmith wrote:
> Why split off the filename and rejoin it here? Is this to better handle cases where the directory exists but the file doesn't, or an attempt to avoid resolving file symlinks? A comment in the code explaining this would be useful.
If I understand correctly, getCanonicalName only works with a DirectoryEntry, which is supposed to be a directory, not a full path to a file. So I didn't see any other way than getting the canonical name for the dir, and then joining it with the filename.


https://reviews.llvm.org/D23816