From 513164232d897c39c4e571a7a8f167dee5c146b3 Mon Sep 17 00:00:00 2001
From: David Allsopp <david.allsopp@metastack.com>
Date: Wed, 18 May 2022 12:48:33 +0100
Subject: [PATCH 05/24] Guard more instances of undefined _MSC_VER

---
 Changes               |  8 +++++---
 runtime/caml/memory.h |  2 +-
 runtime/caml/misc.h   | 12 +++++++-----
 3 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/Changes b/Changes
index fdfffd78bb..590268262d 100644
--- a/Changes
+++ b/Changes
@@ -8,9 +8,11 @@ OCaml 4.14 maintenance branch
   the class definition.
   (Nicolás Ojeda Bär, review by Leo White)
 
-- #11263: caml/misc.h: check whether `_MSC_VER` is defined before using it. This
-  could break the build of the compiler on non-gcc non-clang Unix builds.
-  (Nicolás Ojeda Bär, review by Sebastien Hinderer)
+- #11263, #11267: caml/{memory,misc}.h: check whether `_MSC_VER` is defined
+  before using it to ensure that the headers can always be used in code which
+  turns on -Wundef (or equivalent).
+  (David Allsopp and Nicolás Ojeda Bär, review by Nicolás Ojeda Bär and
+   Sebastien Hinderer)
 
 OCaml 4.14.0 (28 March 2022)
 ----------------------------
diff --git a/runtime/caml/memory.h b/runtime/caml/memory.h
index 1e9cdf6d9b..d9e58bc2d0 100644
--- a/runtime/caml/memory.h
+++ b/runtime/caml/memory.h
@@ -329,7 +329,7 @@ struct caml__roots_block {
   #define CAMLunused_start __attribute__ ((unused))
   #define CAMLunused_end
   #define CAMLunused __attribute__ ((unused))
-#elif _MSC_VER >= 1500
+#elif defined(_MSC_VER) && _MSC_VER >= 1500
   #define CAMLunused_start  __pragma( warning (push) )           \
     __pragma( warning (disable:4189 ) )
   #define CAMLunused_end __pragma( warning (pop))
diff --git a/runtime/caml/misc.h b/runtime/caml/misc.h
index 494d45e8f8..c605f8711e 100644
--- a/runtime/caml/misc.h
+++ b/runtime/caml/misc.h
@@ -43,7 +43,8 @@
   #define CAMLdeprecated_typedef(name, type) typedef type name
 #endif
 
-#if defined(__GNUC__) && __STDC_VERSION__ >= 199901L || _MSC_VER >= 1925
+#if defined(__GNUC__) && __STDC_VERSION__ >= 199901L \
+ || defined(_MSC_VER) && _MSC_VER >= 1925
 
 #define CAML_STRINGIFY(x) #x
 #ifdef _MSC_VER
@@ -90,7 +91,7 @@ CAMLdeprecated_typedef(addr, char *);
   #define CAMLnoreturn_start
   #define CAMLnoreturn_end __attribute__ ((noreturn))
   #define Noreturn __attribute__ ((noreturn))
-#elif _MSC_VER >= 1500
+#elif defined(_MSC_VER) && _MSC_VER >= 1500
   #define CAMLnoreturn_start __declspec(noreturn)
   #define CAMLnoreturn_end
   #define Noreturn
@@ -138,11 +139,12 @@ CAMLdeprecated_typedef(addr, char *);
 /* we need to be able to compute the exact offset of each member. */
 #if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L
 #define CAMLalign(n) _Alignas(n)
-#elif defined(__cplusplus) && (__cplusplus >= 201103L || _MSC_VER >= 1900)
+#elif defined(__cplusplus) \
+   && (__cplusplus >= 201103L || defined(_MSC_VER) && _MSC_VER >= 1900)
 #define CAMLalign(n) alignas(n)
 #elif defined(SUPPORTS_ALIGNED_ATTRIBUTE)
 #define CAMLalign(n) __attribute__((aligned(n)))
-#elif _MSC_VER >= 1500
+#elif defined(_MSC_VER) && _MSC_VER >= 1500
 #define CAMLalign(n) __declspec(align(n))
 #else
 #error "How do I align values on this platform?"
@@ -170,7 +172,7 @@ CAMLdeprecated_typedef(addr, char *);
   #define CAMLunused_start __attribute__ ((unused))
   #define CAMLunused_end
   #define CAMLunused __attribute__ ((unused))
-#elif _MSC_VER >= 1500
+#elif defined(_MSC_VER) && _MSC_VER >= 1500
   #define CAMLunused_start  __pragma( warning (push) )           \
     __pragma( warning (disable:4189 ) )
   #define CAMLunused_end __pragma( warning (pop))
-- 
2.37.0.rc2