From 1ff41cad716adeba0d408652c92c81e59e3ba316 Mon Sep 17 00:00:00 2001
From: Dimitry Andric <dim@FreeBSD.org>
Date: Mon, 25 Dec 2023 18:18:31 +0100
Subject: [PATCH] Minimize libc++ errno-related header diffs with upstream

In commit 88640c0e8b6f5 the new EINTEGRITY errno value was added, and
this caused us to carry a patch for upstream libc++ since that time.
Because it can cause merge conflicts when importing libc++ code from
upstream, I have submitted an upstream pull request to get most of that
patch integrated.

It turns out that we do not need the errno.h part of it at all, since
all supported FreeBSD versions define EOWNERDEAD and ENOTRECOVERABLE,
and therefore the block that juggles with ELAST values is never used in
FreeBSD. At the moment it only applies to older versions of Linux, or
possibly other platforms.

Therefore the only part that needs to stay is the definition of a enum
errc value for EINTEGRITY, and this is made optional upon EINTEGRITY
being defined, to make it suitable for upstreaming.

No functional change is intended.

MFC after:	1 week
---
 .../libcxx/include/__system_error/errc.h      |  2 +
 contrib/llvm-project/libcxx/include/errno.h   | 66 +++++--------------
 2 files changed, 18 insertions(+), 50 deletions(-)

diff --git a/contrib/llvm-project/libcxx/include/__system_error/errc.h b/contrib/llvm-project/libcxx/include/__system_error/errc.h
index f0c27b1c60a1..f939c99f7ed6 100644
--- a/contrib/llvm-project/libcxx/include/__system_error/errc.h
+++ b/contrib/llvm-project/libcxx/include/__system_error/errc.h
@@ -143,7 +143,9 @@ _LIBCPP_DECLARE_STRONG_ENUM(errc)
     identifier_removed                  = EIDRM,
     illegal_byte_sequence               = EILSEQ,
     inappropriate_io_control_operation  = ENOTTY,
+#ifdef EINTEGRITY
     integrity_check_failed              = EINTEGRITY,
+#endif
     interrupted                         = EINTR,
     invalid_argument                    = EINVAL,
     invalid_seek                        = ESPIPE,
diff --git a/contrib/llvm-project/libcxx/include/errno.h b/contrib/llvm-project/libcxx/include/errno.h
index ea96c3a0f004..7b02d2b47953 100644
--- a/contrib/llvm-project/libcxx/include/errno.h
+++ b/contrib/llvm-project/libcxx/include/errno.h
@@ -34,79 +34,49 @@
 
 #ifdef __cplusplus
 
-#if !defined(EOWNERDEAD) || !defined(ENOTRECOVERABLE) || !defined(EINTEGRITY)
+#if !defined(EOWNERDEAD) || !defined(ENOTRECOVERABLE)
 
-#if defined(ELAST)
+#ifdef ELAST
 
 static const int __elast1 = ELAST+1;
 static const int __elast2 = ELAST+2;
-static const int __elast3 = ELAST+3;
 
 #else
 
 static const int __elast1 = 104;
 static const int __elast2 = 105;
-static const int __elast3 = 106;
 
 #endif
 
-#if !defined(EOWNERDEAD) && !defined(ENOTRECOVERABLE) && !defined(EINTEGRITY)
-#define ENOTRECOVERABLE __elast1
-#define EOWNERDEAD __elast2
-#define EINTEGRITY __elast3
-#if defined(ELAST)
-#undef ELAST
-#define ELAST EINTEGRITY
-#endif
+#ifdef ENOTRECOVERABLE
 
-#elif !defined(EOWNERDEAD) && !defined(ENOTRECOVERABLE) && defined(EINTEGRITY)
-#define ENOTRECOVERABLE __elast1
-#define EOWNERDEAD __elast2
-#if defined(ELAST)
+#define EOWNERDEAD __elast1
+
+#ifdef ELAST
 #undef ELAST
 #define ELAST EOWNERDEAD
 #endif
 
-#elif !defined(EOWNERDEAD) && defined(ENOTRECOVERABLE) && !defined(EINTEGRITY)
-#define EOWNERDEAD __elast1
-#define EINTEGRITY __elast2
-#if defined(ELAST)
-#undef ELAST
-#define ELAST EINTEGRITY
-#endif
+#elif defined(EOWNERDEAD)
 
-#elif !defined(EOWNERDEAD) && defined(ENOTRECOVERABLE) && defined(EINTEGRITY)
-#define EOWNERDEAD __elast1
-#if defined(ELAST)
-#undef ELAST
-#define ELAST EOWNERDEAD
-#endif
-
-#elif defined(EOWNERDEAD) && !defined(ENOTRECOVERABLE) && !defined(EINTEGRITY)
 #define ENOTRECOVERABLE __elast1
-#define EINTEGRITY __elast2
-#if defined(ELAST)
-#undef ELAST
-#define ELAST EINTEGRITY
-#endif
-
-#elif defined(EOWNERDEAD) && !defined(ENOTRECOVERABLE) && defined(EINTEGRITY)
-#define ENOTRECOVERABLE __elast1
-#if defined(ELAST)
+#ifdef ELAST
 #undef ELAST
 #define ELAST ENOTRECOVERABLE
 #endif
 
-#elif defined(EOWNERDEAD) && defined(ENOTRECOVERABLE) && !defined(EINTEGRITY)
-#define EINTEGRITY __elast1
-#if defined(ELAST)
+#else  // defined(EOWNERDEAD)
+
+#define EOWNERDEAD __elast1
+#define ENOTRECOVERABLE __elast2
+#ifdef ELAST
 #undef ELAST
-#define ELAST EINTEGRITY
+#define ELAST ENOTRECOVERABLE
 #endif
 
-#endif // !defined(OWNERDEAD) && !defined(NOTRECOVERABLE) && !defined(INTEGRITY)
+#endif // defined(EOWNERDEAD)
 
-#endif // !defined(OWNERDEAD) || !defined(NOTRECOVERABLE) || !defined(INTEGRITY)
+#endif // !defined(EOWNERDEAD) || !defined(ENOTRECOVERABLE)
 
 //  supply errno values likely to be missing, particularly on Windows
 
@@ -424,10 +394,6 @@ static const int __elast3 = 106;
 #define EMLINK 9979
 #endif
 
-#ifndef EINTEGRITY
-#define EINTEGRITY 9980
-#endif
-
 #endif // __cplusplus
 
 #endif // _LIBCPP_ERRNO_H