[PATCH] D122545: Skip attemps to access /proc/self/fd on FreeBSD

[Mateusz Guzik via Phabricator via llvm-commits]

mjguzik created this revision.
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In contrast to Linux it does not provide entries which can be readlinked, resulting in the path used to open the file. That's on top of procfs not being mounted by default to begin with.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D122545

Files:
  llvm/lib/Support/Unix/Path.inc


Index: llvm/lib/Support/Unix/Path.inc
===================================================================
--- llvm/lib/Support/Unix/Path.inc
+++ llvm/lib/Support/Unix/Path.inc
@@ -950,7 +950,15 @@
   return s;
 }
 
-#if !defined(F_GETPATH)
+/*
+ * FreeBSD optionally provides /proc/self/fd, but it is incompatible with
+ * Linux. The thing to use is realpath.
+ */
+#if !defined(__FreeBSD__)
+#define TRY_PROC_SELF_FD
+#endif
+
+#if !defined(F_GETPATH) && defined(TRY_PROC_SELF_FD)
 static bool hasProcSelfFD() {
   // If we have a /proc filesystem mounted, we can quickly establish the
   // real name of the file with readlink
@@ -1137,6 +1145,7 @@
     RealPath->append(Buffer, Buffer + strlen(Buffer));
 #else
   char Buffer[PATH_MAX];
+#if defined(TRY_PROC_SELF_FD)
   if (hasProcSelfFD()) {
     char ProcPath[64];
     snprintf(ProcPath, sizeof(ProcPath), "/proc/self/fd/%d", ResultFD);
@@ -1144,13 +1153,16 @@
     if (CharCount > 0)
       RealPath->append(Buffer, Buffer + CharCount);
   } else {
+#endif
     SmallString<128> Storage;
     StringRef P = Name.toNullTerminatedStringRef(Storage);
 
     // Use ::realpath to get the real path name
     if (::realpath(P.begin(), Buffer) != nullptr)
       RealPath->append(Buffer, Buffer + strlen(Buffer));
+#if defined(TRY_PROC_SELF_FD)
   }
+#endif
 #endif
   return std::error_code();
 }


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