config: Split out some of util.h into a new header

1 files changed, 189 insertions, 0 deletions

diff --git a/src/config.h b/src/config.h
new file mode 100644
index 0000000..5bd49de
--- /dev/null
+++ b/src/config.h
@@ -0,0 +1,189 @@
+/****************************************************************************
+ * bfs                                                                      *
+ * Copyright (C) 2015-2022 Tavian Barnes <tavianator@tavianator.com>        *
+ *                                                                          *
+ * Permission to use, copy, modify, and/or distribute this software for any *
+ * purpose with or without fee is hereby granted.                           *
+ *                                                                          *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES *
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF         *
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR  *
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES   *
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN    *
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF  *
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.           *
+ ****************************************************************************/
+
+/**
+ * Configuration and feature/platform detection.
+ */
+
+#ifndef BFS_CONFIG_H
+#define BFS_CONFIG_H
+
+#include <stdbool.h>
+#include <stddef.h>
+
+// bfs packaging configuration
+
+#ifndef BFS_COMMAND
+#	define BFS_COMMAND "bfs"
+#endif
+#ifndef BFS_VERSION
+#	define BFS_VERSION "2.6.2"
+#endif
+#ifndef BFS_HOMEPAGE
+#	define BFS_HOMEPAGE "https://tavianator.com/projects/bfs.html"
+#endif
+
+// Check for system headers
+
+#ifdef __has_include
+
+#if __has_include(<mntent.h>)
+#	define BFS_HAS_MNTENT_H true
+#endif
+#if __has_include(<paths.h>)
+#	define BFS_HAS_PATHS_H true
+#endif
+#if __has_include(<sys/acl.h>)
+#	define BFS_HAS_SYS_ACL_H true
+#endif
+#if __has_include(<sys/capability.h>)
+#	define BFS_HAS_SYS_CAPABILITY_H true
+#endif
+#if __has_include(<sys/extattr.h>)
+#	define BFS_HAS_SYS_EXTATTR_H true
+#endif
+#if __has_include(<sys/mkdev.h>)
+#	define BFS_HAS_SYS_MKDEV_H true
+#endif
+#if __has_include(<sys/param.h>)
+#	define BFS_HAS_SYS_PARAM_H true
+#endif
+#if __has_include(<sys/sysmacros.h>)
+#	define BFS_HAS_SYS_SYSMACROS_H true
+#endif
+#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
+
+#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
+
+// Stub out feature detection on old/incompatible compilers
+
+#ifndef __has_feature
+#	define __has_feature(feat) false
+#endif
+
+#ifndef __has_c_attribute
+#	define __has_c_attribute(attr) false
+#endif
+
+#ifndef __has_attribute
+#	define __has_attribute(attr) false
+#endif
+
+// Platform detection
+
+// Get the definition of BSD if available
+#if BFS_USE_SYS_PARAM_H
+#	include <sys/param.h>
+#endif
+
+#ifndef __GLIBC_PREREQ
+#	define __GLIBC_PREREQ(maj, min) false
+#endif
+
+// Wrappers for fundamental language features/extensions
+
+/**
+ * Silence compiler warnings about switch/case fall-throughs.
+ */
+#if __has_c_attribute(fallthrough)
+#	define BFS_FALLTHROUGH [[fallthrough]]
+#elif __has_attribute(fallthrough)
+#	define BFS_FALLTHROUGH __attribute__((fallthrough))
+#else
+#	define BFS_FALLTHROUGH ((void)0)
+#endif
+
+// Lower bound on BFS_FLEX_SIZEOF()
+#define BFS_FLEX_LB(type, member, length) (offsetof(type, member) + sizeof(((type *)NULL)->member[0]) * (length))
+
+// Maximum macro for BFS_FLEX_SIZE()
+#define BFS_FLEX_MAX(a, b) ((a) > (b) ? (a) : (b))
+
+/**
+ * Computes the size of a struct containing a flexible array member of the given
+ * length.
+ *
+ * @param type
+ *         The type of the struct containing the flexible array.
+ * @param member
+ *         The name of the flexible array member.
+ * @param length
+ *         The length of the flexible array.
+ */
+#define BFS_FLEX_SIZEOF(type, member, length) \
+	(sizeof(type) <= BFS_FLEX_LB(type, member, 0) \
+		? BFS_FLEX_LB(type, member, length) \
+		: BFS_FLEX_MAX(sizeof(type), BFS_FLEX_LB(type, member, length)))
+
+/**
+ * Adds compiler warnings for bad printf()-style function calls, if supported.
+ */
+#if __has_attribute(format)
+#	define BFS_FORMATTER(fmt, args) __attribute__((format(printf, fmt, args)))
+#else
+#	define BFS_FORMATTER(fmt, args)
+#endif
+
+#endif // BFS_CONFIG_H