From 40139738eb479d0913ec6ce751ca5adfa50ad8c3 Mon Sep 17 00:00:00 2001
From: dundargoc <gocdundar@gmail.com>
Date: Sun, 26 Nov 2023 21:36:02 +0100
Subject: [PATCH] build: enable IWYU on mac

---
 Makefile                      |   2 +-
 cmake.config/iwyu/mapping.imp |   7 +-
 cmake.config/iwyu/posix.imp   | 117 ++++++----------------------------
 src/nvim/CMakeLists.txt       |   1 +
 src/nvim/base64.c             |   2 +-
 src/nvim/buffer_defs.h        |   2 +-
 src/nvim/cmdexpand.c          |   1 +
 src/nvim/edit.c               |   1 +
 src/nvim/eval.c               |   1 +
 src/nvim/eval/typval.c        |   1 +
 src/nvim/event/rstream.c      |   2 +-
 src/nvim/ex_docmd.c           |   1 +
 src/nvim/fileio.c             |   1 +
 src/nvim/keycodes.c           |   1 +
 src/nvim/lua/stdlib.c         |   2 +-
 src/nvim/main.c               |  21 +++---
 src/nvim/marktree.c           |   1 +
 src/nvim/mbyte.c              |   1 +
 src/nvim/memline.c            |   1 +
 src/nvim/message.c            |   1 +
 src/nvim/ops.c                |   1 +
 src/nvim/os/fileio.c          |   4 ++
 src/nvim/os/fs.c              |   2 -
 src/nvim/os/process.c         |  12 +++-
 src/nvim/os/signal.c          |   6 +-
 src/nvim/os/time.c            |   2 -
 src/nvim/os/unix_defs.h       |  17 +++--
 src/nvim/ui_compositor.c      |   2 +-
 src/nvim/undo.c               |   1 +
 29 files changed, 82 insertions(+), 132 deletions(-)

diff --git a/Makefile b/Makefile
index 0ce89ae39f..e65a39e9f0 100644
--- a/Makefile
+++ b/Makefile
@@ -141,7 +141,7 @@ test: $(TEST)
 iwyu: build/.ran-cmake
 	cmake --preset iwyu
 	cmake --build build > build/iwyu.log
-	iwyu-fix-includes --only_re="src/nvim" --ignore_re="(src/nvim/eval/encode.c|src/nvim/auto/\
+	iwyu-fix-includes --only_re="src/nvim" --ignore_re="(src/nvim/eval/encode.c|src/nvim/auto/|src/nvim/os/lang.c|src/nvim/map.c\
 	|src/nvim/api/autocmd.h\
 	|src/nvim/api/buffer.h\
 	|src/nvim/api/command.h\
diff --git a/cmake.config/iwyu/mapping.imp b/cmake.config/iwyu/mapping.imp
index ae857e87da..8c693fecda 100644
--- a/cmake.config/iwyu/mapping.imp
+++ b/cmake.config/iwyu/mapping.imp
@@ -17,12 +17,11 @@
   # Symbols
   { symbol: [ "MAX", private, '"nvim/macros.h"', public ] },
   { symbol: [ "MIN", private, '"nvim/macros.h"', public ] },
+  { symbol: [ "extern_proc", private, '<uv.h>', public ] },
+  { symbol: [ "iovec", private, '<sys/uio.h>', public ] },
 
   # Third party headers
-  { include: [ '<netdb.h>', public, '"nvim/os/unix_defs.h"', private ] },
-  { include: [ '<netinet/in.h>', public, '"nvim/os/unix_defs.h"', private ] },
-  { include: [ '<pthread.h>', public, '"nvim/os/unix_defs.h"', private ] },
-  { include: [ '<uv/unix.h>', public, '<uv.h>', public ] },
+  { include: [ '<uv/unix.h>', private, '<uv.h>', public ] },
 ]
 
 # vim: set ft=toml:
diff --git a/cmake.config/iwyu/posix.imp b/cmake.config/iwyu/posix.imp
index b15c1186d9..2eabd3063b 100644
--- a/cmake.config/iwyu/posix.imp
+++ b/cmake.config/iwyu/posix.imp
@@ -1,110 +1,33 @@
 [
-  # bits/ioctls.h
+  { include: [ "<arm/limits.h>", private, "<limits.h>", public ] },
   { include: [ "<asm/ioctls.h>", private, "<bits/ioctls.h>", private ] },
-
-  # errno.h
-  { symbol: ["E2BIG", private, "<errno.h>", public ] },
-  { symbol: ["EACCES", private, "<errno.h>", public ] },
-  { symbol: ["EADDRINUSE", private, "<errno.h>", public ] },
-  { symbol: ["EADDRNOTAVAIL", private, "<errno.h>", public ] },
-  { symbol: ["EAFNOSUPPORT", private, "<errno.h>", public ] },
-  { symbol: ["EAGAIN", private, "<errno.h>", public ] },
-  { symbol: ["EALREADY", private, "<errno.h>", public ] },
-  { symbol: ["EBADF", private, "<errno.h>", public ] },
-  { symbol: ["EBADMSG", private, "<errno.h>", public ] },
-  { symbol: ["EBUSY", private, "<errno.h>", public ] },
-  { symbol: ["ECANCELED", private, "<errno.h>", public ] },
-  { symbol: ["ECHILD", private, "<errno.h>", public ] },
-  { symbol: ["ECONNABORTED", private, "<errno.h>", public ] },
-  { symbol: ["ECONNREFUSED", private, "<errno.h>", public ] },
-  { symbol: ["ECONNRESET", private, "<errno.h>", public ] },
-  { symbol: ["EDEADLK", private, "<errno.h>", public ] },
-  { symbol: ["EDESTADDRREQ", private, "<errno.h>", public ] },
-  { symbol: ["EDOM", private, "<errno.h>", public ] },
-  { symbol: ["EDQUOT", private, "<errno.h>", public ] },
-  { symbol: ["EEXIST", private, "<errno.h>", public ] },
-  { symbol: ["EFAULT", private, "<errno.h>", public ] },
-  { symbol: ["EFBIG", private, "<errno.h>", public ] },
-  { symbol: ["EHOSTUNREACH", private, "<errno.h>", public ] },
-  { symbol: ["EIDRM", private, "<errno.h>", public ] },
-  { symbol: ["EILSEQ", private, "<errno.h>", public ] },
-  { symbol: ["EINPROGRESS", private, "<errno.h>", public ] },
-  { symbol: ["EINTR", private, "<errno.h>", public ] },
-  { symbol: ["EINVAL", private, "<errno.h>", public ] },
-  { symbol: ["EIO", private, "<errno.h>", public ] },
-  { symbol: ["EISCONN", private, "<errno.h>", public ] },
-  { symbol: ["EISDIR", private, "<errno.h>", public ] },
-  { symbol: ["ELOOP", private, "<errno.h>", public ] },
-  { symbol: ["EMFILE", private, "<errno.h>", public ] },
-  { symbol: ["EMLINK", private, "<errno.h>", public ] },
-  { symbol: ["EMSGSIZE", private, "<errno.h>", public ] },
-  { symbol: ["EMULTIHOP", private, "<errno.h>", public ] },
-  { symbol: ["ENAMETOOLONG", private, "<errno.h>", public ] },
-  { symbol: ["ENETDOWN", private, "<errno.h>", public ] },
-  { symbol: ["ENETRESET", private, "<errno.h>", public ] },
-  { symbol: ["ENETUNREACH", private, "<errno.h>", public ] },
-  { symbol: ["ENFILE", private, "<errno.h>", public ] },
-  { symbol: ["ENOBUFS", private, "<errno.h>", public ] },
-  { symbol: ["ENODATA", private, "<errno.h>", public ] },
-  { symbol: ["ENODEV", private, "<errno.h>", public ] },
-  { symbol: ["ENOENT", private, "<errno.h>", public ] },
-  { symbol: ["ENOEXEC", private, "<errno.h>", public ] },
-  { symbol: ["ENOLCK", private, "<errno.h>", public ] },
-  { symbol: ["ENOLINK", private, "<errno.h>", public ] },
-  { symbol: ["ENOMEM", private, "<errno.h>", public ] },
-  { symbol: ["ENOMSG", private, "<errno.h>", public ] },
-  { symbol: ["ENOPROTOOPT", private, "<errno.h>", public ] },
-  { symbol: ["ENOSPC", private, "<errno.h>", public ] },
-  { symbol: ["ENOSR", private, "<errno.h>", public ] },
-  { symbol: ["ENOSTR", private, "<errno.h>", public ] },
-  { symbol: ["ENOSYS", private, "<errno.h>", public ] },
-  { symbol: ["ENOTCONN", private, "<errno.h>", public ] },
-  { symbol: ["ENOTDIR", private, "<errno.h>", public ] },
-  { symbol: ["ENOTEMPTY", private, "<errno.h>", public ] },
-  { symbol: ["ENOTRECOVERABLE", private, "<errno.h>", public ] },
-  { symbol: ["ENOTSOCK", private, "<errno.h>", public ] },
-  { symbol: ["ENOTSUP", private, "<errno.h>", public ] },
-  { symbol: ["ENOTTY", private, "<errno.h>", public ] },
-  { symbol: ["ENXIO", private, "<errno.h>", public ] },
-  { symbol: ["EOPNOTSUPP", private, "<errno.h>", public ] },
-  { symbol: ["EOVERFLOW", private, "<errno.h>", public ] },
-  { symbol: ["EOWNERDEAD", private, "<errno.h>", public ] },
-  { symbol: ["EPERM", private, "<errno.h>", public ] },
-  { symbol: ["EPIPE", private, "<errno.h>", public ] },
-  { symbol: ["EPROTO", private, "<errno.h>", public ] },
-  { symbol: ["EPROTONOSUPPORT", private, "<errno.h>", public ] },
-  { symbol: ["EPROTOTYPE", private, "<errno.h>", public ] },
-  { symbol: ["ERANGE", private, "<errno.h>", public ] },
-  { symbol: ["EROFS", private, "<errno.h>", public ] },
-  { symbol: ["ESPIPE", private, "<errno.h>", public ] },
-  { symbol: ["ESRCH", private, "<errno.h>", public ] },
-  { symbol: ["ESTALE", private, "<errno.h>", public ] },
-  { symbol: ["ETIME", private, "<errno.h>", public ] },
-  { symbol: ["ETIMEDOUT", private, "<errno.h>", public ] },
-  { symbol: ["ETXTBSY", private, "<errno.h>", public ] },
-  { symbol: ["EWOULDBLOCK", private, "<errno.h>", public ] },
-  { symbol: ["EXDEV", private, "<errno.h>", public ] },
-
-  # limits.h
-  { symbol: ["SSIZE_MAX", private, "<limits.h>", public ] },
-
-  # signal.h
-  { symbol: [ "sigset_t", private, "<signal.h>", public ] },
-
-  # sys/socket.h
-  { symbol: [ "iovec", private, "<sys/socket.h>", public ] },
-  { symbol: ["SOCK_STREAM", private, "<sys/socket.h>", public ] },
-
-  # termios.h
   { include: [ "<bits/termios-c_lflag.h>", private, "<termios.h>", public ] },
   { include: [ "<bits/termios-struct.h>", private, "<termios.h>", public ] },
+  { include: [ "<sys/errno.h>", private, "<errno.h>", public ] },
+  { include: [ "<sys/fcntl.h>", private, "<fcntl.h>", public ] },
+  { include: [ "<sys/signal.h>", private, "<signal.h>", public ] },
+  { include: [ "<sys/termios.h>", private, "<termios.h>", public ] },
+  { include: [ '<asm/errno-base.h>', private, '<errno.h>', public ] },
+  { include: [ '<asm/errno.h>', private, '<errno.h>', public ] },
   { include: [ '<bits/termios-c_cc.h>', private, '<termios.h>', public ] },
   { include: [ '<bits/termios-c_cflag.h>', private, '<termios.h>', public ] },
   { include: [ '<bits/termios-c_iflag.h>', private, '<termios.h>', public ] },
   { include: [ '<bits/termios-c_oflag.h>', private, '<termios.h>', public ] },
+  { include: [ '<sys/unistd.h>', private, '<unistd.h>', public ] },
 
-  # <unistd.h
+  { symbol: ["SOCK_STREAM", private, "<sys/socket.h>", public ] },
+  { symbol: ["SSIZE_MAX", private, "<limits.h>", public ] },
+  { symbol: ["S_IREAD", private, "<sys/stat.h>", public ] },
+  { symbol: ["S_IWRITE", private, "<sys/stat.h>", public ] },
   { symbol: ["_POSIX_VDISABLE", private, "<unistd.h>", public ] },
+  { symbol: ["flock", private, "<sys/file.h>", public ] },
+  { symbol: ["iovec", private, "<sys/uio.h>", public ] },
+  { symbol: ["mode_t", private, "<sys/types.h>", public ] },
+  { symbol: ["ntohs", private, "<arpa/inet.h>", public ] },
+  { symbol: ["pthread_sigmask", private, "<signal.h>", public ] },
+  { symbol: ["sigset_t", private, "<signal.h>", public ] },
+  { symbol: ["ssize_t", private, "<sys/types.h>", public ] },
+  { symbol: ["uid_t", private, "<sys/types.h>", public ] },
 ]
 
 # vim: set ft=toml:
diff --git a/src/nvim/CMakeLists.txt b/src/nvim/CMakeLists.txt
index 59af5e3818..3505f8be4f 100644
--- a/src/nvim/CMakeLists.txt
+++ b/src/nvim/CMakeLists.txt
@@ -259,6 +259,7 @@ if(ENABLE_IWYU)
 
   set(iwyu_flags "${IWYU_PRG};")
   string(APPEND iwyu_flags "-Xiwyu;--no_default_mappings;")
+  string(APPEND iwyu_flags "-Xiwyu;--no_fwd_decls;")
   string(APPEND iwyu_flags "-Xiwyu;--mapping_file=${PROJECT_SOURCE_DIR}/cmake.config/iwyu/mapping.imp")
 
   set_target_properties(nvim PROPERTIES C_INCLUDE_WHAT_YOU_USE "${iwyu_flags}")
diff --git a/src/nvim/base64.c b/src/nvim/base64.c
index 5bc0c34f06..295dedd8d3 100644
--- a/src/nvim/base64.c
+++ b/src/nvim/base64.c
@@ -3,7 +3,7 @@
 #include <stdint.h>
 #include <string.h>
 
-#include "auto/config.h"
+#include "auto/config.h"  // IWYU pragma: keep
 #include "nvim/base64.h"
 #include "nvim/memory.h"
 
diff --git a/src/nvim/buffer_defs.h b/src/nvim/buffer_defs.h
index 803d2aa0c6..0e7e5723cd 100644
--- a/src/nvim/buffer_defs.h
+++ b/src/nvim/buffer_defs.h
@@ -4,7 +4,7 @@
 #include <stdint.h>
 #include <stdio.h>
 
-typedef struct file_buffer buf_T;  // Forward declaration
+typedef struct file_buffer buf_T;
 
 /// Reference to a buffer that stores the value of buf_free_count.
 /// bufref_valid() only needs to check "buf" when the count differs.
diff --git a/src/nvim/cmdexpand.c b/src/nvim/cmdexpand.c
index 7a6cc02cb8..58ec3d31bf 100644
--- a/src/nvim/cmdexpand.c
+++ b/src/nvim/cmdexpand.c
@@ -6,6 +6,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/types.h>
 
 #include "nvim/api/private/defs.h"
 #include "nvim/api/private/helpers.h"
diff --git a/src/nvim/edit.c b/src/nvim/edit.c
index 7b21cc5bdb..23a246dcf5 100644
--- a/src/nvim/edit.c
+++ b/src/nvim/edit.c
@@ -9,6 +9,7 @@
 
 #include "nvim/ascii.h"
 #include "nvim/autocmd.h"
+#include "nvim/autocmd_defs.h"
 #include "nvim/buffer.h"
 #include "nvim/change.h"
 #include "nvim/charset.h"
diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index 52ab610267..d48e126229 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -7,6 +7,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <sys/stat.h>
+#include <sys/types.h>
 
 #include "auto/config.h"
 #include "nvim/api/private/converter.h"
diff --git a/src/nvim/eval/typval.c b/src/nvim/eval/typval.c
index e8ed6e5d32..936e043b6a 100644
--- a/src/nvim/eval/typval.c
+++ b/src/nvim/eval/typval.c
@@ -5,6 +5,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/types.h>
 
 #include "nvim/ascii.h"
 #include "nvim/assert.h"
diff --git a/src/nvim/event/rstream.c b/src/nvim/event/rstream.c
index 218293e44a..7745cd8fcc 100644
--- a/src/nvim/event/rstream.c
+++ b/src/nvim/event/rstream.c
@@ -2,7 +2,7 @@
 #include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
-#include <stdio.h>
+#include <sys/types.h>
 #include <uv.h>
 
 #include "nvim/event/loop.h"
diff --git a/src/nvim/ex_docmd.c b/src/nvim/ex_docmd.c
index 373dd8cd96..12aeb509fb 100644
--- a/src/nvim/ex_docmd.c
+++ b/src/nvim/ex_docmd.c
@@ -9,6 +9,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/types.h>
 
 #include "auto/config.h"
 #include "nvim/arglist.h"
diff --git a/src/nvim/fileio.c b/src/nvim/fileio.c
index 6de6f01a52..dcc1b8eea5 100644
--- a/src/nvim/fileio.c
+++ b/src/nvim/fileio.c
@@ -11,6 +11,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <sys/stat.h>
+#include <sys/types.h>
 #include <time.h>
 #include <uv.h>
 
diff --git a/src/nvim/keycodes.c b/src/nvim/keycodes.c
index e2fb1fa3ee..aa61b40476 100644
--- a/src/nvim/keycodes.c
+++ b/src/nvim/keycodes.c
@@ -4,6 +4,7 @@
 #include <stdbool.h>
 #include <stdio.h>
 #include <string.h>
+#include <sys/types.h>
 
 #include "nvim/ascii.h"
 #include "nvim/charset.h"
diff --git a/src/nvim/lua/stdlib.c b/src/nvim/lua/stdlib.c
index c1e0af5aa1..a200b0a32f 100644
--- a/src/nvim/lua/stdlib.c
+++ b/src/nvim/lua/stdlib.c
@@ -5,8 +5,8 @@
 #include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
-#include <stdio.h>
 #include <string.h>
+#include <sys/types.h>
 
 #ifdef NVIM_VENDOR_BIT
 # include "bit.h"
diff --git a/src/nvim/main.c b/src/nvim/main.c
index c5ab9f0cb2..68659d8a54 100644
--- a/src/nvim/main.c
+++ b/src/nvim/main.c
@@ -21,6 +21,11 @@
 #include "nvim/vim.h"
 // uncrustify:on
 
+#include "auto/config.h"  // IWYU pragma: keep
+#include "nvim/api/extmark.h"
+#include "nvim/api/private/defs.h"
+#include "nvim/api/private/helpers.h"
+#include "nvim/api/ui.h"
 #include "nvim/arglist.h"
 #include "nvim/ascii.h"
 #include "nvim/autocmd.h"
@@ -34,7 +39,9 @@
 #include "nvim/eval.h"
 #include "nvim/eval/typval.h"
 #include "nvim/eval/userfunc.h"
+#include "nvim/event/loop.h"
 #include "nvim/event/multiqueue.h"
+#include "nvim/event/process.h"
 #include "nvim/event/stream.h"
 #include "nvim/ex_cmds.h"
 #include "nvim/ex_docmd.h"
@@ -61,6 +68,9 @@
 #include "nvim/message.h"
 #include "nvim/mouse.h"
 #include "nvim/move.h"
+#include "nvim/msgpack_rpc/channel.h"
+#include "nvim/msgpack_rpc/helpers.h"
+#include "nvim/msgpack_rpc/server.h"
 #include "nvim/normal.h"
 #include "nvim/ops.h"
 #include "nvim/option.h"
@@ -71,6 +81,7 @@
 #include "nvim/os/input.h"
 #include "nvim/os/lang.h"
 #include "nvim/os/os.h"
+#include "nvim/os/signal.h"
 #include "nvim/os/stdpaths_defs.h"
 #include "nvim/path.h"
 #include "nvim/popupmenu.h"
@@ -91,16 +102,6 @@
 #ifdef MSWIN
 # include "nvim/os/os_win_console.h"
 #endif
-#include "nvim/api/extmark.h"
-#include "nvim/api/private/defs.h"
-#include "nvim/api/private/helpers.h"
-#include "nvim/api/ui.h"
-#include "nvim/event/loop.h"
-#include "nvim/event/process.h"
-#include "nvim/msgpack_rpc/channel.h"
-#include "nvim/msgpack_rpc/helpers.h"
-#include "nvim/msgpack_rpc/server.h"
-#include "nvim/os/signal.h"
 
 // values for "window_layout"
 enum {
diff --git a/src/nvim/marktree.c b/src/nvim/marktree.c
index 6f6a91eae0..cffeb077f8 100644
--- a/src/nvim/marktree.c
+++ b/src/nvim/marktree.c
@@ -47,6 +47,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/types.h>
 
 #include "klib/kvec.h"
 #include "nvim/garray.h"
diff --git a/src/nvim/mbyte.c b/src/nvim/mbyte.c
index 1151e80e4c..a2c0e70d77 100644
--- a/src/nvim/mbyte.c
+++ b/src/nvim/mbyte.c
@@ -32,6 +32,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/types.h>
 #include <wctype.h>
 
 #include "auto/config.h"
diff --git a/src/nvim/memline.c b/src/nvim/memline.c
index ea7a61b8dd..f9169030a6 100644
--- a/src/nvim/memline.c
+++ b/src/nvim/memline.c
@@ -39,6 +39,7 @@
 #include <stddef.h>
 #include <stdio.h>
 #include <string.h>
+#include <sys/types.h>
 #include <time.h>
 #include <uv.h>
 
diff --git a/src/nvim/message.c b/src/nvim/message.c
index 032f079f46..641ceff2e8 100644
--- a/src/nvim/message.c
+++ b/src/nvim/message.c
@@ -8,6 +8,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/types.h>
 
 #include "nvim/api/private/helpers.h"
 #include "nvim/ascii.h"
diff --git a/src/nvim/ops.c b/src/nvim/ops.c
index c6f7c74d6b..1144829a17 100644
--- a/src/nvim/ops.c
+++ b/src/nvim/ops.c
@@ -9,6 +9,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/types.h>
 
 #include "nvim/api/private/defs.h"
 #include "nvim/ascii.h"
diff --git a/src/nvim/os/fileio.c b/src/nvim/os/fileio.c
index b205481e98..55c12f2986 100644
--- a/src/nvim/os/fileio.c
+++ b/src/nvim/os/fileio.c
@@ -28,6 +28,10 @@
 # include "nvim/os/os_win_console.h"
 #endif
 
+#ifdef HAVE_SYS_UIO_H
+# include <sys/uio.h>
+#endif
+
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "os/fileio.c.generated.h"
 #endif
diff --git a/src/nvim/os/fs.c b/src/nvim/os/fs.c
index b9448ddf4b..4721bc3f1c 100644
--- a/src/nvim/os/fs.c
+++ b/src/nvim/os/fs.c
@@ -67,8 +67,6 @@ static const char e_xattr_other[]
   = N_("E1509: Error occurred when reading or writing extended attribute");
 #endif
 
-struct iovec;
-
 #define RUN_UV_FS_FUNC(ret, func, ...) \
   do { \
     uv_fs_t req; \
diff --git a/src/nvim/os/process.c b/src/nvim/os/process.c
index 889d1f453f..7b47ba7020 100644
--- a/src/nvim/os/process.c
+++ b/src/nvim/os/process.c
@@ -3,18 +3,19 @@
 /// psutil is a good reference for cross-platform syscall voodoo:
 /// https://github.com/giampaolo/psutil/tree/master/psutil/arch
 
+// IWYU pragma: no_include <sys/param.h>
+
 #include <assert.h>
 #include <signal.h>
 #include <stdbool.h>
 #include <stddef.h>
-#include <stdio.h>
 #include <uv.h>
 
 #ifdef MSWIN
 # include <tlhelp32.h>
 #endif
 
-#if defined(__FreeBSD__)  // XXX: OpenBSD ?
+#if defined(__FreeBSD__)
 # include <string.h>
 # include <sys/types.h>
 # include <sys/user.h>
@@ -25,8 +26,13 @@
 #endif
 
 #if defined(__APPLE__) || defined(BSD)
-# include <pwd.h>
 # include <sys/sysctl.h>
+
+# include "nvim/macros.h"
+#endif
+
+#if defined(__linux__)
+# include <stdio.h>
 #endif
 
 #include "nvim/log.h"
diff --git a/src/nvim/os/signal.c b/src/nvim/os/signal.c
index e73a579a27..3a861b87b4 100644
--- a/src/nvim/os/signal.c
+++ b/src/nvim/os/signal.c
@@ -1,6 +1,7 @@
 #include <assert.h>
 #include <stdbool.h>
 #include <stdio.h>
+
 #ifndef MSWIN
 # include <signal.h>
 #endif
@@ -11,9 +12,12 @@
 #include "nvim/globals.h"
 #include "nvim/log.h"
 #include "nvim/main.h"
-#include "nvim/memline.h"
 #include "nvim/os/signal.h"
 
+#ifdef SIGPWR
+# include "nvim/memline.h"
+#endif
+
 static SignalWatcher spipe, shup, squit, sterm, susr1, swinch;
 #ifdef SIGPWR
 static SignalWatcher spwr;
diff --git a/src/nvim/os/time.c b/src/nvim/os/time.c
index 8aa3170963..be95412c01 100644
--- a/src/nvim/os/time.c
+++ b/src/nvim/os/time.c
@@ -17,8 +17,6 @@
 #include "nvim/os/os.h"
 #include "nvim/os/time.h"
 
-struct tm;
-
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "os/time.c.generated.h"  // IWYU pragma: export
 #endif
diff --git a/src/nvim/os/unix_defs.h b/src/nvim/os/unix_defs.h
index fe5dce5655..d2bec7b361 100644
--- a/src/nvim/os/unix_defs.h
+++ b/src/nvim/os/unix_defs.h
@@ -1,15 +1,18 @@
 #pragma once
 // IWYU pragma: private, include "nvim/os/os_defs.h"
 
-#include <sys/param.h>  // IWYU pragma: export
-#include <sys/socket.h>  // IWYU pragma: export
-#include <unistd.h>  // IWYU pragma: export
+// IWYU pragma: begin_exports
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <pthread.h>
+#include <sys/param.h>
+#include <sys/socket.h>
+#include <unistd.h>
 #if defined(HAVE_TERMIOS_H)
-# include <termios.h>  // IWYU pragma: export
+# include <termios.h>
 #endif
-
-// POSIX.1-2008 says that NAME_MAX should be in here
-#include <limits.h>
+// IWYU pragma: end_exports
 
 #define TEMP_DIR_NAMES { "$TMPDIR", "/tmp", ".", "~" }
 #define TEMP_FILE_PATH_MAXLEN 256
diff --git a/src/nvim/ui_compositor.c b/src/nvim/ui_compositor.c
index b1751f32fd..b243e1088b 100644
--- a/src/nvim/ui_compositor.c
+++ b/src/nvim/ui_compositor.c
@@ -7,9 +7,9 @@
 #include <inttypes.h>
 #include <limits.h>
 #include <stdbool.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/types.h>
 
 #include "klib/kvec.h"
 #include "nvim/api/private/defs.h"
diff --git a/src/nvim/undo.c b/src/nvim/undo.c
index 15577931f3..288b23f56c 100644
--- a/src/nvim/undo.c
+++ b/src/nvim/undo.c
@@ -77,6 +77,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/types.h>
 #include <time.h>
 #include <uv.h>