util: Get rid of BFS_HAS_INCLUDE() wrapper for __has_include()

Since __has_include() needs special preprocessing rules (e.g. not
expanding `linux` in `__has_include(<linux/stat.h>)`, macros that expand
to __has_include() do not necessarily behave correctly.  Instead, we
have to directly test `#if __has_include(...)`.

See https://bugs.llvm.org/show_bug.cgi?id=37990 for more details.

9 files changed, 84 insertions, 51 deletions

diff --git a/Makefile b/Makefile
index bf99a8e..a251234 100644
--- a/Makefile
+++ b/Makefile
@@ -106,19 +106,19 @@ endif
 ifdef WITH_ACL
 LOCAL_LDLIBS += -lacl
 else
-LOCAL_CPPFLAGS += -DBFS_HAS_SYS_ACL=0
+LOCAL_CPPFLAGS += -DBFS_USE_SYS_ACL_H=0
 endif
 
 ifdef WITH_ATTR
 LOCAL_LDLIBS += -lattr
 else
-LOCAL_CPPFLAGS += -DBFS_HAS_SYS_XATTR=0
+LOCAL_CPPFLAGS += -DBFS_USE_SYS_XATTR_H=0
 endif
 
 ifdef WITH_LIBCAP
 LOCAL_LDLIBS += -lcap
 else
-LOCAL_CPPFLAGS += -DBFS_HAS_SYS_CAPABILITY=0
+LOCAL_CPPFLAGS += -DBFS_USE_SYS_CAPABILITY_H=0
 endif
 
 LOCAL_LDFLAGS += -Wl,--as-needed
diff --git a/src/fsade.c b/src/fsade.c
index 9e5374f..7a7201e 100644
--- a/src/fsade.c
+++ b/src/fsade.c
@@ -32,9 +32,9 @@
 #	include <sys/capability.h>
 #endif
 
-#if BFS_HAS_SYS_EXTATTR
+#if BFS_USE_SYS_EXTATTR_H
 #	include <sys/extattr.h>
-#elif BFS_HAS_SYS_XATTR
+#elif BFS_USE_SYS_XATTR_H
 #	include <sys/xattr.h>
 #endif
 
@@ -303,7 +303,7 @@ int bfs_check_xattrs(const struct BFTW *ftwbuf) {
 	const char *path = fake_at(ftwbuf);
 	ssize_t len;
 
-#if BFS_HAS_SYS_EXTATTR
+#if BFS_USE_SYS_EXTATTR_H
 	ssize_t (*extattr_list)(const char *, int, void*, size_t) =
 		ftwbuf->type == BFS_LNK ? extattr_list_link : extattr_list_file;
 
@@ -342,7 +342,7 @@ int bfs_check_xattr_named(const struct BFTW *ftwbuf, const char *name) {
 	const char *path = fake_at(ftwbuf);
 	ssize_t len;
 
-#if BFS_HAS_SYS_EXTATTR
+#if BFS_USE_SYS_EXTATTR_H
 	ssize_t (*extattr_get)(const char *, int, const char *, void*, size_t) =
 		ftwbuf->type == BFS_LNK ? extattr_get_link : extattr_get_file;
 
diff --git a/src/fsade.h b/src/fsade.h
index e964112..bd7fc5b 100644
--- a/src/fsade.h
+++ b/src/fsade.h
@@ -25,16 +25,16 @@
 #include "util.h"
 #include <stdbool.h>
 
-#define BFS_CAN_CHECK_ACL BFS_HAS_SYS_ACL
+#define BFS_CAN_CHECK_ACL BFS_USE_SYS_ACL_H
 
-#if !defined(BFS_CAN_CHECK_CAPABILITIES) && BFS_HAS_SYS_CAPABILITY && !__FreeBSD__
+#if !defined(BFS_CAN_CHECK_CAPABILITIES) && BFS_USE_SYS_CAPABILITY_H && !__FreeBSD__
 #	include <sys/capability.h>
 #	ifdef CAP_CHOWN
 #		define BFS_CAN_CHECK_CAPABILITIES true
 #	endif
 #endif
 
-#define BFS_CAN_CHECK_XATTRS (BFS_HAS_SYS_EXTATTR || BFS_HAS_SYS_XATTR)
+#define BFS_CAN_CHECK_XATTRS (BFS_USE_SYS_EXTATTR_H || BFS_USE_SYS_XATTR_H)
 
 struct BFTW;
 
diff --git a/src/mtab.c b/src/mtab.c
index adc3f58..a9f5b41 100644
--- a/src/mtab.c
+++ b/src/mtab.c
@@ -26,11 +26,11 @@
 #include <string.h>
 #include <sys/types.h>
 
-#if BFS_HAS_SYS_PARAM
+#if BFS_USE_SYS_PARAM_H
 #	include <sys/param.h>
 #endif
 
-#if BFS_HAS_MNTENT
+#if BFS_USE_MNTENT_H
 #	define BFS_MNTENT 1
 #elif BSD
 #	define BFS_MNTINFO 1
diff --git a/src/stat.c b/src/stat.c
index ab3282a..cc20697 100644
--- a/src/stat.c
+++ b/src/stat.c
@@ -24,7 +24,7 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 
-#if BFS_HAS_SYS_PARAM
+#if BFS_USE_SYS_PARAM_H
 #	include <sys/param.h>
 #endif
 
diff --git a/src/stat.h b/src/stat.h
index 55c75e9..f45302a 100644
--- a/src/stat.h
+++ b/src/stat.h
@@ -29,7 +29,7 @@
 #include <sys/types.h>
 #include <time.h>
 
-#if BFS_HAS_SYS_PARAM
+#if BFS_USE_SYS_PARAM_H
 #	include <sys/param.h>
 #endif
 
diff --git a/src/util.c b/src/util.c
index b1a038a..bb2e1cc 100644
--- a/src/util.c
+++ b/src/util.c
@@ -31,17 +31,17 @@
 #include <unistd.h>
 #include <wchar.h>
 
-#if BFS_HAS_SYS_PARAM
+#if BFS_USE_SYS_PARAM_H
 #	include <sys/param.h>
 #endif
 
-#if BFS_HAS_SYS_SYSMACROS
+#if BFS_USE_SYS_SYSMACROS_H
 #	include <sys/sysmacros.h>
-#elif BFS_HAS_SYS_MKDEV
+#elif BFS_USE_SYS_MKDEV_H
 #	include <sys/mkdev.h>
 #endif
 
-#if BFS_HAS_UTIL
+#if BFS_USE_UTIL_H
 #	include <util.h>
 #endif
 
diff --git a/src/util.h b/src/util.h
index ffa5bcc..0fbcdaa 100644
--- a/src/util.h
+++ b/src/util.h
@@ -43,49 +43,82 @@
 #endif
 
 #ifdef __has_include
-#	define BFS_HAS_INCLUDE(header, fallback) __has_include(header)
-#else
-#	define BFS_HAS_INCLUDE(header, fallback) fallback
-#endif
 
-#ifndef BFS_HAS_MNTENT
-#	define BFS_HAS_MNTENT BFS_HAS_INCLUDE(<mntent.h>, __GLIBC__)
+#if __has_include(<mntent.h>)
+#	define BFS_HAS_MNTENT_H true
 #endif
-
-#ifndef BFS_HAS_PATHS
-#	define BFS_HAS_PATHS BFS_HAS_INCLUDE(<paths.h>, true)
+#if __has_include(<paths.h>)
+#	define BFS_HAS_PATHS_H true
 #endif
-
-#ifndef BFS_HAS_SYS_ACL
-#	define BFS_HAS_SYS_ACL BFS_HAS_INCLUDE(<sys/acl.h>, true)
+#if __has_include(<sys/acl.h>)
+#	define BFS_HAS_SYS_ACL_H true
 #endif
-
-#ifndef BFS_HAS_SYS_CAPABILITY
-#	define BFS_HAS_SYS_CAPABILITY BFS_HAS_INCLUDE(<sys/capability.h>, __linux__)
+#if __has_include(<sys/capability.h>)
+#	define BFS_HAS_SYS_CAPABILITY_H true
 #endif
-
-#ifndef BFS_HAS_SYS_EXTATTR
-#	define BFS_HAS_SYS_EXTATTR BFS_HAS_INCLUDE(<sys/extattr.h>, __FreeBSD__)
+#if __has_include(<sys/extattr.h>)
+#	define BFS_HAS_SYS_EXTATTR_H true
 #endif
-
-#ifndef BFS_HAS_SYS_MKDEV
-#	define BFS_HAS_SYS_MKDEV BFS_HAS_INCLUDE(<sys/mkdev.h>, false)
+#if __has_include(<sys/mkdev.h>)
+#	define BFS_HAS_SYS_MKDEV_H true
 #endif
-
-#ifndef BFS_HAS_SYS_PARAM
-#	define BFS_HAS_SYS_PARAM BFS_HAS_INCLUDE(<sys/param.h>, true)
+#if __has_include(<sys/param.h>)
+#	define BFS_HAS_SYS_PARAM_H true
 #endif
-
-#ifndef BFS_HAS_SYS_SYSMACROS
-#	define BFS_HAS_SYS_SYSMACROS BFS_HAS_INCLUDE(<sys/sysmacros.h>, __GLIBC__)
+#if __has_include(<sys/sysmacros.h>)
+#	define BFS_HAS_SYS_SYSMACROS_H true
 #endif
-
-#ifndef BFS_HAS_SYS_XATTR
-#	define BFS_HAS_SYS_XATTR BFS_HAS_INCLUDE(<sys/xattr.h>, __linux__)
+#if __has_include(<sys/xattr.h>)
+#	define BFS_HAS_SYS_XATTR_H true
+#endif
+#if __has_include(<util.h>)
+#	define BFS_HAS_UTIL_H true
 #endif
 
-#ifndef BFS_HAS_UTIL
-#	define BFS_HAS_UTIL BFS_HAS_INCLUDE(<util.h>, __NetBSD__)
+#else // !__has_include
+
+#define BFS_HAS_MNTENT_H __GLIBC__
+#define BFS_HAS_PATHS_H true
+#define BFS_HAS_SYS_ACL_H true
+#define BFS_HAS_SYS_CAPABILITY_H __linux__
+#define BFS_HAS_SYS_EXTATTR_H __FreeBSD__
+#define BFS_HAS_SYS_MKDEV_H false
+#define BFS_HAS_SYS_PARAM_H true
+#define BFS_HAS_SYS_SYSMACROS_H __GLIBC__
+#define BFS_HAS_SYS_XATTR_H __linux__
+#define BFS_HAS_UTIL_H __NetBSD__
+
+#endif // !__has_include
+
+#ifndef BFS_USE_MNTENT_H
+#	define BFS_USE_MNTENT_H BFS_HAS_MNTENT_H
+#endif
+#ifndef BFS_USE_PATHS_H
+#	define BFS_USE_PATHS_H BFS_HAS_PATHS_H
+#endif
+#ifndef BFS_USE_SYS_ACL_H
+#	define BFS_USE_SYS_ACL_H BFS_HAS_SYS_ACL_H
+#endif
+#ifndef BFS_USE_SYS_CAPABILITY_H
+#	define BFS_USE_SYS_CAPABILITY_H BFS_HAS_SYS_CAPABILITY_H
+#endif
+#ifndef BFS_USE_SYS_EXTATTR_H
+#	define BFS_USE_SYS_EXTATTR_H BFS_HAS_SYS_EXTATTR_H
+#endif
+#ifndef BFS_USE_SYS_MKDEV_H
+#	define BFS_USE_SYS_MKDEV_H BFS_HAS_SYS_MKDEV_H
+#endif
+#ifndef BFS_USE_SYS_PARAM_H
+#	define BFS_USE_SYS_PARAM_H BFS_HAS_SYS_PARAM_H
+#endif
+#ifndef BFS_USE_SYS_SYSMACROS_H
+#	define BFS_USE_SYS_SYSMACROS_H BFS_HAS_SYS_SYSMACROS_H
+#endif
+#ifndef BFS_USE_SYS_XATTR_H
+#	define BFS_USE_SYS_XATTR_H BFS_HAS_SYS_XATTR_H
+#endif
+#ifndef BFS_USE_UTIL_H
+#	define BFS_USE_UTIL_H BFS_HAS_UTIL_H
 #endif
 
 #ifndef __GLIBC_PREREQ
diff --git a/src/xspawn.c b/src/xspawn.c
index 43a6f1c..bcaeb35 100644
--- a/src/xspawn.c
+++ b/src/xspawn.c
@@ -24,7 +24,7 @@
 #include <sys/wait.h>
 #include <unistd.h>
 
-#if BFS_HAS_PATHS
+#if BFS_USE_PATHS_H
 #	include <paths.h>
 #endif