prelude: Simplify attributes

20 files changed, 125 insertions, 179 deletions

diff --git a/src/alloc.c b/src/alloc.c
index ebaff38..d7a70e9 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -176,7 +176,7 @@ void arena_init(struct arena *arena, size_t align, size_t size) {
 }
 
 /** Allocate a new slab. */
-attr(cold)
+_cold
 static int slab_alloc(struct arena *arena) {
 	// Make the initial allocation size ~4K
 	size_t size = 4096;
diff --git a/src/alloc.h b/src/alloc.h
index 095134a..6b863f2 100644
--- a/src/alloc.h
+++ b/src/alloc.h
@@ -115,7 +115,8 @@ static inline size_t flex_size(size_t align, size_t min, size_t offset, size_t s
  * @return
  *         The allocated memory, or NULL on failure.
  */
-attr(malloc(free, 1), aligned_alloc(1, 2))
+_malloc(free, 1)
+_aligned_alloc(1, 2)
 void *alloc(size_t align, size_t size);
 
 /**
@@ -128,7 +129,8 @@ void *alloc(size_t align, size_t size);
  * @return
  *         The allocated memory, or NULL on failure.
  */
-attr(malloc(free, 1), aligned_alloc(1, 2))
+_malloc(free, 1)
+_aligned_alloc(1, 2)
 void *zalloc(size_t align, size_t size);
 
 /** Allocate memory for the given type. */
@@ -169,7 +171,8 @@ void *zalloc(size_t align, size_t size);
  * @return
  *         The reallocated memory, or NULL on failure.
  */
-attr(nodiscard, aligned_alloc(2, 4))
+_aligned_alloc(2, 4)
+_nodiscard
 void *xrealloc(void *ptr, size_t align, size_t old_size, size_t new_size);
 
 /** Reallocate memory for an array. */
@@ -195,7 +198,7 @@ void *xrealloc(void *ptr, size_t align, size_t old_size, size_t new_size);
  *         for (count + 1) elements.  On failure, errno will be non-zero, and
  *         ptr will returned unchanged.
  */
-attr(nodiscard)
+_nodiscard
 void *reserve(void *ptr, size_t align, size_t size, size_t count);
 
 /**
@@ -253,7 +256,7 @@ void arena_free(struct arena *arena, void *ptr);
 /**
  * Allocate an object out of the arena.
  */
-attr(malloc(arena_free, 2))
+_malloc(arena_free, 2)
 void *arena_alloc(struct arena *arena);
 
 /**
@@ -335,7 +338,7 @@ void varena_free(struct varena *varena, void *ptr, size_t count);
  * @return
  *         The allocated struct, or NULL on failure.
  */
-attr(malloc(varena_free, 2))
+_malloc(varena_free, 2)
 void *varena_alloc(struct varena *varena, size_t count);
 
 /**
@@ -352,7 +355,7 @@ void *varena_alloc(struct varena *varena, size_t count);
  * @return
  *         The resized struct, or NULL on failure.
  */
-attr(nodiscard)
+_nodiscard
 void *varena_realloc(struct varena *varena, void *ptr, size_t old_count, size_t new_count);
 
 /**
@@ -367,7 +370,7 @@ void *varena_realloc(struct varena *varena, void *ptr, size_t old_count, size_t
  * @return
  *         The resized struct, or NULL on failure.
  */
-attr(nodiscard)
+_nodiscard
 void *varena_grow(struct varena *varena, void *ptr, size_t *count);
 
 /**
diff --git a/src/bar.c b/src/bar.c
index be77694..64706a8 100644
--- a/src/bar.c
+++ b/src/bar.c
@@ -122,7 +122,7 @@ static void bfs_bar_sigexit(int sig, siginfo_t *info, void *arg) {
 }
 
 /** printf() to the status bar with a single write(). */
-attr(printf(2, 3))
+_printf(2, 3)
 static int bfs_bar_printf(struct bfs_bar *bar, const char *format, ...) {
 	va_list args;
 	va_start(args, format);
diff --git a/src/color.c b/src/color.c
index 13a4e08..052de69 100644
--- a/src/color.c
+++ b/src/color.c
@@ -1119,7 +1119,7 @@ static int print_link_target(CFILE *cfile, const struct BFTW *ftwbuf) {
 }
 
 /** Format some colored output to the buffer. */
-attr(printf(2, 3))
+_printf(2, 3)
 static int cbuff(CFILE *cfile, const char *format, ...);
 
 /** Dump a parsed expression tree, for debugging. */
@@ -1188,7 +1188,7 @@ static int print_expr(CFILE *cfile, const struct bfs_expr *expr, bool verbose, i
 	return 0;
 }
 
-attr(printf(2, 0))
+_printf(2, 0)
 static int cvbuff(CFILE *cfile, const char *format, va_list args) {
 	const struct colors *colors = cfile->colors;
 
diff --git a/src/color.h b/src/color.h
index 8582eb3..6847e3b 100644
--- a/src/color.h
+++ b/src/color.h
@@ -100,13 +100,13 @@ int cfclose(CFILE *cfile);
  * @return
  *         0 on success, -1 on failure.
  */
-attr(printf(2, 3))
+_printf(2, 3)
 int cfprintf(CFILE *cfile, const char *format, ...);
 
 /**
  * cfprintf() variant that takes a va_list.
  */
-attr(printf(2, 0))
+_printf(2, 0)
 int cvfprintf(CFILE *cfile, const char *format, va_list args);
 
 /**
diff --git a/src/diag.c b/src/diag.c
index ccafd98..6ae088c 100644
--- a/src/diag.c
+++ b/src/diag.c
@@ -15,7 +15,7 @@
 #include <stdlib.h>
 
 /** bfs_diagf() implementation. */
-attr(printf(2, 0))
+_printf(2, 0)
 static void bfs_vdiagf(const struct bfs_loc *loc, const char *format, va_list args) {
 	fprintf(stderr, "%s: %s@%s:%d: ", xgetprogname(), loc->func, loc->file, loc->line);
 	vfprintf(stderr, format, args);
@@ -29,7 +29,8 @@ void bfs_diagf(const struct bfs_loc *loc, const char *format, ...) {
 	va_end(args);
 }
 
-noreturn void bfs_abortf(const struct bfs_loc *loc, const char *format, ...) {
+_noreturn
+void bfs_abortf(const struct bfs_loc *loc, const char *format, ...) {
 	va_list args;
 	va_start(args, format);
 	bfs_vdiagf(loc, format, args);
diff --git a/src/diag.h b/src/diag.h
index da22f3a..d70bd43 100644
--- a/src/diag.h
+++ b/src/diag.h
@@ -47,7 +47,7 @@ struct bfs_loc {
  *
  *     bfs: func@src/file.c:0: Message
  */
-attr(printf(2, 3))
+_printf(2, 3)
 void bfs_diagf(const struct bfs_loc *loc, const char *format, ...);
 
 /**
@@ -67,8 +67,10 @@ void bfs_diagf(const struct bfs_loc *loc, const char *format, ...);
 /**
  * Print a message to standard error and abort.
  */
-attr(cold, printf(2, 3))
-noreturn void bfs_abortf(const struct bfs_loc *loc, const char *format, ...);
+_cold
+_printf(2, 3)
+_noreturn
+void bfs_abortf(const struct bfs_loc *loc, const char *format, ...);
 
 /**
  * Unconditional abort with a message.
@@ -166,13 +168,14 @@ const char *debug_flag_name(enum debug_flags flag);
 /**
  * Like perror(), but decorated like bfs_error().
  */
-attr(cold)
+_cold
 void bfs_perror(const struct bfs_ctx *ctx, const char *str);
 
 /**
  * Shorthand for printing error messages.
  */
-attr(cold, printf(2, 3))
+_cold
+_printf(2, 3)
 void bfs_error(const struct bfs_ctx *ctx, const char *format, ...);
 
 /**
@@ -180,7 +183,8 @@ void bfs_error(const struct bfs_ctx *ctx, const char *format, ...);
  *
  * @return Whether a warning was printed.
  */
-attr(cold, printf(2, 3))
+_cold
+_printf(2, 3)
 bool bfs_warning(const struct bfs_ctx *ctx, const char *format, ...);
 
 /**
@@ -188,67 +192,71 @@ bool bfs_warning(const struct bfs_ctx *ctx, const char *format, ...);
  *
  * @return Whether a debug message was printed.
  */
-attr(cold, printf(3, 4))
+_cold
+_printf(3, 4)
 bool bfs_debug(const struct bfs_ctx *ctx, enum debug_flags flag, const char *format, ...);
 
 /**
  * bfs_error() variant that takes a va_list.
  */
-attr(cold, printf(2, 0))
+_cold
+_printf(2, 0)
 void bfs_verror(const struct bfs_ctx *ctx, const char *format, va_list args);
 
 /**
  * bfs_warning() variant that takes a va_list.
  */
-attr(cold, printf(2, 0))
+_cold
+_printf(2, 0)
 bool bfs_vwarning(const struct bfs_ctx *ctx, const char *format, va_list args);
 
 /**
  * bfs_debug() variant that takes a va_list.
  */
-attr(cold, printf(3, 0))
+_cold
+_printf(3, 0)
 bool bfs_vdebug(const struct bfs_ctx *ctx, enum debug_flags flag, const char *format, va_list args);
 
 /**
  * Print the error message prefix.
  */
-attr(cold)
+_cold
 void bfs_error_prefix(const struct bfs_ctx *ctx);
 
 /**
  * Print the warning message prefix.
  */
-attr(cold)
+_cold
 bool bfs_warning_prefix(const struct bfs_ctx *ctx);
 
 /**
  * Print the debug message prefix.
  */
-attr(cold)
+_cold
 bool bfs_debug_prefix(const struct bfs_ctx *ctx, enum debug_flags flag);
 
 /**
  * Highlight parts of the command line in an error message.
  */
-attr(cold)
+_cold
 void bfs_argv_error(const struct bfs_ctx *ctx, const bool args[]);
 
 /**
  * Highlight parts of an expression in an error message.
  */
-attr(cold)
+_cold
 void bfs_expr_error(const struct bfs_ctx *ctx, const struct bfs_expr *expr);
 
 /**
  * Highlight parts of the command line in a warning message.
  */
-attr(cold)
+_cold
 bool bfs_argv_warning(const struct bfs_ctx *ctx, const bool args[]);
 
 /**
  * Highlight parts of an expression in a warning message.
  */
-attr(cold)
+_cold
 bool bfs_expr_warning(const struct bfs_ctx *ctx, const struct bfs_expr *expr);
 
 #endif // BFS_DIAG_H
diff --git a/src/dstring.h b/src/dstring.h
index 14e1d3e..46d5edb 100644
--- a/src/dstring.h
+++ b/src/dstring.h
@@ -41,7 +41,7 @@ void dstrfree(dchar *dstr);
  * @param cap
  *         The initial capacity of the string.
  */
-attr(malloc(dstrfree, 1))
+_malloc(dstrfree, 1)
 dchar *dstralloc(size_t cap);
 
 /**
@@ -50,7 +50,7 @@ dchar *dstralloc(size_t cap);
  * @param str
  *         The NUL-terminated string to copy.
  */
-attr(malloc(dstrfree, 1))
+_malloc(dstrfree, 1)
 dchar *dstrdup(const char *str);
 
 /**
@@ -61,7 +61,7 @@ dchar *dstrdup(const char *str);
  * @param n
  *         The maximum number of characters to copy from str.
  */
-attr(malloc(dstrfree, 1))
+_malloc(dstrfree, 1)
 dchar *dstrndup(const char *str, size_t n);
 
 /**
@@ -70,7 +70,7 @@ dchar *dstrndup(const char *str, size_t n);
  * @param dstr
  *         The dynamic string to copy.
  */
-attr(malloc(dstrfree, 1))
+_malloc(dstrfree, 1)
 dchar *dstrddup(const dchar *dstr);
 
 /**
@@ -81,7 +81,7 @@ dchar *dstrddup(const dchar *dstr);
  * @param len
  *         The length of the string, which may include internal NUL bytes.
  */
-attr(malloc(dstrfree, 1))
+_malloc(dstrfree, 1)
 dchar *dstrxdup(const char *str, size_t len);
 
 /**
@@ -243,7 +243,7 @@ int dstrxcpy(dchar **dest, const char *str, size_t len);
  * @return
  *         The created string, or NULL on failure.
  */
-attr(printf(1, 2))
+_printf(1, 2)
 dchar *dstrprintf(const char *format, ...);
 
 /**
@@ -256,7 +256,7 @@ dchar *dstrprintf(const char *format, ...);
  * @return
  *         The created string, or NULL on failure.
  */
-attr(printf(1, 0))
+_printf(1, 0)
 dchar *dstrvprintf(const char *format, va_list args);
 
 /**
@@ -271,7 +271,7 @@ dchar *dstrvprintf(const char *format, va_list args);
  * @return
  *         0 on success, -1 on failure.
  */
-attr(printf(2, 3))
+_printf(2, 3)
 int dstrcatf(dchar **str, const char *format, ...);
 
 /**
@@ -286,7 +286,7 @@ int dstrcatf(dchar **str, const char *format, ...);
  * @return
  *         0 on success, -1 on failure.
  */
-attr(printf(2, 0))
+_printf(2, 0)
 int dstrvcatf(dchar **str, const char *format, va_list args);
 
 /**
diff --git a/src/eval.c b/src/eval.c
index 0b5992e..2c88669 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -60,7 +60,7 @@ struct bfs_eval {
 /**
  * Print an error message.
  */
-attr(printf(2, 3))
+_printf(2, 3)
 static void eval_error(struct bfs_eval *state, const char *format, ...) {
 	// By POSIX, any errors should be accompanied by a non-zero exit status
 	*state->ret = EXIT_FAILURE;
diff --git a/src/exec.c b/src/exec.c
index 2faa731..05c4189 100644
--- a/src/exec.c
+++ b/src/exec.c
@@ -22,7 +22,7 @@
 #include <unistd.h>
 
 /** Print some debugging info. */
-attr(printf(2, 3))
+_printf(2, 3)
 static void bfs_exec_debug(const struct bfs_exec *execbuf, const char *format, ...) {
 	const struct bfs_ctx *ctx = execbuf->ctx;
 
diff --git a/src/fsade.c b/src/fsade.c
index 7310141..11dcd9b 100644
--- a/src/fsade.c
+++ b/src/fsade.c
@@ -36,7 +36,7 @@
  * Many of the APIs used here don't have *at() variants, but we can try to
  * emulate something similar if /proc/self/fd is available.
  */
-attr(maybe_unused)
+_maybe_unused
 static const char *fake_at(const struct BFTW *ftwbuf) {
 	static atomic int proc_works = -1;
 
@@ -70,7 +70,7 @@ fail:
 	return ftwbuf->path;
 }
 
-attr(maybe_unused)
+_maybe_unused
 static void free_fake_at(const struct BFTW *ftwbuf, const char *path) {
 	if (path != ftwbuf->path) {
 		dstrfree((dchar *)path);
@@ -80,7 +80,7 @@ static void free_fake_at(const struct BFTW *ftwbuf, const char *path) {
 /**
  * Check if an error was caused by the absence of support or data for a feature.
  */
-attr(maybe_unused)
+_maybe_unused
 static bool is_absence_error(int error) {
 	// If the OS doesn't support the feature, it's obviously not enabled for
 	// any files
@@ -160,7 +160,7 @@ static int bfs_acl_entry(acl_t acl, int which, acl_entry_t *entry) {
 }
 
 /** Unified interface for acl_get_tag_type(). */
-attr(maybe_unused)
+_maybe_unused
 static int bfs_acl_tag_type(acl_entry_t entry, acl_tag_t *tag) {
 #if BFS_HAS_ACL_GET_TAG_TYPE
 	return acl_get_tag_type(entry, tag);
diff --git a/src/ioq.c b/src/ioq.c
index 6bb1ceb..50898c6 100644
--- a/src/ioq.c
+++ b/src/ioq.c
@@ -263,7 +263,7 @@ static struct ioq_monitor *ioq_slot_monitor(struct ioqq *ioqq, ioq_slot *slot) {
 }
 
 /** Atomically wait for a slot to change. */
-attr(noinline)
+_noinline
 static uintptr_t ioq_slot_wait(struct ioqq *ioqq, ioq_slot *slot, uintptr_t value) {
 	struct ioq_monitor *monitor = ioq_slot_monitor(ioqq, slot);
 	mutex_lock(&monitor->mutex);
@@ -293,7 +293,7 @@ done:
 }
 
 /** Wake up any threads waiting on a slot. */
-attr(noinline)
+_noinline
 static void ioq_slot_wake(struct ioqq *ioqq, ioq_slot *slot) {
 	struct ioq_monitor *monitor = ioq_slot_monitor(ioqq, slot);
 
diff --git a/src/mtab.c b/src/mtab.c
index 0377fea..dbe17cc 100644
--- a/src/mtab.c
+++ b/src/mtab.c
@@ -65,7 +65,7 @@ struct bfs_mtab {
 /**
  * Add an entry to the mount table.
  */
-attr(maybe_unused)
+_maybe_unused
 static int bfs_mtab_add(struct bfs_mtab *mtab, const char *path, const char *type) {
 	size_t path_size = strlen(path) + 1;
 	size_t type_size = strlen(type) + 1;
diff --git a/src/opt.c b/src/opt.c
index d81b7d8..ccd76c8 100644
--- a/src/opt.c
+++ b/src/opt.c
@@ -370,7 +370,7 @@ struct bfs_opt {
 };
 
 /** Log an optimization. */
-attr(printf(2, 3))
+_printf(2, 3)
 static bool opt_debug(struct bfs_opt *opt, const char *format, ...) {
 	if (bfs_debug_prefix(opt->ctx, DEBUG_OPT)) {
 		for (int i = 0; i < opt->depth; ++i) {
@@ -388,7 +388,7 @@ static bool opt_debug(struct bfs_opt *opt, const char *format, ...) {
 }
 
 /** Log a recursive call. */
-attr(printf(2, 3))
+_printf(2, 3)
 static bool opt_enter(struct bfs_opt *opt, const char *format, ...) {
 	int depth = opt->depth;
 	if (depth > 0) {
@@ -408,7 +408,7 @@ static bool opt_enter(struct bfs_opt *opt, const char *format, ...) {
 }
 
 /** Log a recursive return. */
-attr(printf(2, 3))
+_printf(2, 3)
 static bool opt_leave(struct bfs_opt *opt, const char *format, ...) {
 	bool debug = false;
 	int depth = opt->depth;
@@ -432,7 +432,7 @@ static bool opt_leave(struct bfs_opt *opt, const char *format, ...) {
 }
 
 /** Log a shallow visit. */
-attr(printf(2, 3))
+_printf(2, 3)
 static bool opt_visit(struct bfs_opt *opt, const char *format, ...) {
 	int depth = opt->depth;
 	if (depth > 0) {
@@ -452,7 +452,7 @@ static bool opt_visit(struct bfs_opt *opt, const char *format, ...) {
 }
 
 /** Log the deletion of an expression. */
-attr(printf(2, 3))
+_printf(2, 3)
 static bool opt_delete(struct bfs_opt *opt, const char *format, ...) {
 	int depth = opt->depth;
 
@@ -614,7 +614,7 @@ static bool is_const(const struct bfs_expr *expr) {
 }
 
 /** Warn about an expression. */
-attr(printf(3, 4))
+_printf(3, 4)
 static void opt_warning(const struct bfs_opt *opt, const struct bfs_expr *expr, const char *format, ...) {
 	if (!opt->warn) {
 		return;
diff --git a/src/parse.c b/src/parse.c
index c225778..02a795d 100644
--- a/src/parse.c
+++ b/src/parse.c
@@ -165,7 +165,7 @@ static void highlight_args(const struct bfs_ctx *ctx, char **argv, size_t argc,
 /**
  * Print an error message during parsing.
  */
-attr(printf(2, 3))
+_printf(2, 3)
 static void parse_error(const struct bfs_parser *parser, const char *format, ...) {
 	const struct bfs_ctx *ctx = parser->ctx;
 
@@ -183,7 +183,7 @@ static void parse_error(const struct bfs_parser *parser, const char *format, ...
 /**
  * Print an error about some command line arguments.
  */
-attr(printf(4, 5))
+_printf(4, 5)
 static void parse_argv_error(const struct bfs_parser *parser, char **argv, size_t argc, const char *format, ...) {
 	const struct bfs_ctx *ctx = parser->ctx;
 
@@ -201,7 +201,7 @@ static void parse_argv_error(const struct bfs_parser *parser, char **argv, size_
 /**
  * Print an error about conflicting command line arguments.
  */
-attr(printf(6, 7))
+_printf(6, 7)
 static void parse_conflict_error(const struct bfs_parser *parser, char **argv1, size_t argc1, char **argv2, size_t argc2, const char *format, ...) {
 	const struct bfs_ctx *ctx = parser->ctx;
 
@@ -220,7 +220,7 @@ static void parse_conflict_error(const struct bfs_parser *parser, char **argv1,
 /**
  * Print an error about an expression.
  */
-attr(printf(3, 4))
+_printf(3, 4)
 static void parse_expr_error(const struct bfs_parser *parser, const struct bfs_expr *expr, const char *format, ...) {
 	const struct bfs_ctx *ctx = parser->ctx;
 
@@ -235,7 +235,7 @@ static void parse_expr_error(const struct bfs_parser *parser, const struct bfs_e
 /**
  * Print a warning message during parsing.
  */
-attr(printf(2, 3))
+_printf(2, 3)
 static bool parse_warning(const struct bfs_parser *parser, const char *format, ...) {
 	const struct bfs_ctx *ctx = parser->ctx;
 
@@ -256,7 +256,7 @@ static bool parse_warning(const struct bfs_parser *parser, const char *format, .
 /**
  * Print a warning about conflicting command line arguments.
  */
-attr(printf(6, 7))
+_printf(6, 7)
 static bool parse_conflict_warning(const struct bfs_parser *parser, char **argv1, size_t argc1, char **argv2, size_t argc2, const char *format, ...) {
 	const struct bfs_ctx *ctx = parser->ctx;
 
@@ -278,7 +278,7 @@ static bool parse_conflict_warning(const struct bfs_parser *parser, char **argv1
 /**
  * Print a warning about an expression.
  */
-attr(printf(3, 4))
+_printf(3, 4)
 static bool parse_expr_warning(const struct bfs_parser *parser, const struct bfs_expr *expr, const char *format, ...) {
 	const struct bfs_ctx *ctx = parser->ctx;
 
diff --git a/src/prelude.h b/src/prelude.h
index 34ce803..24de309 100644
--- a/src/prelude.h
+++ b/src/prelude.h
@@ -22,7 +22,6 @@
 #if __STDC_VERSION__ < C23
 #  include <stdalign.h>
 #  include <stdbool.h>
-#  include <stdnoreturn.h>
 #endif
 
 // bfs packaging configuration
@@ -184,54 +183,63 @@ extern const char bfs_ldlibs[];
  * Silence warnings about unused declarations.
  */
 #if __has_attribute(unused)
-#  define attr_maybe_unused __attribute__((unused))
+#  define _maybe_unused __attribute__((unused))
 #else
-#  define attr_maybe_unused
+#  define _maybe_unused
 #endif
 
 /**
  * Warn if a value is unused.
  */
 #if __has_attribute(warn_unused_result)
-#  define attr_nodiscard __attribute__((warn_unused_result))
+#  define _nodiscard __attribute__((warn_unused_result))
 #else
-#  define attr_nodiscard
+#  define _nodiscard
 #endif
 
 /**
  * Hint to avoid inlining a function.
  */
 #if __has_attribute(noinline)
-#  define attr_noinline __attribute__((noinline))
+#  define _noinline __attribute__((noinline))
 #else
-#  define attr_noinline
+#  define _noinline
+#endif
+
+/**
+ * Marks a non-returning function.
+ */
+#if __STDC_VERSION__ >= C23
+#  define _noreturn [[noreturn]]
+#else
+#  define _noreturn _Noreturn
 #endif
 
 /**
  * Hint that a function is unlikely to be called.
  */
 #if __has_attribute(cold)
-#  define attr_cold attr_noinline __attribute__((cold))
+#  define _cold _noinline __attribute__((cold))
 #else
-#  define attr_cold attr_noinline
+#  define _cold _noinline
 #endif
 
 /**
  * Adds compiler warnings for bad printf()-style function calls, if supported.
  */
 #if __has_attribute(format)
-#  define attr_printf(fmt, args) __attribute__((format(printf, fmt, args)))
+#  define _printf(fmt, args) __attribute__((format(printf, fmt, args)))
 #else
-#  define attr_printf(fmt, args)
+#  define _printf(fmt, args)
 #endif
 
 /**
  * Annotates functions that potentially modify and return format strings.
  */
 #if __has_attribute(format_arg)
-#  define attr_format_arg(arg) __attribute__((format_arg(arg)))
+#  define _format_arg(arg) __attribute__((format_arg(arg)))
 #else
-#  define attr_format_arg(args)
+#  define _format_arg(arg)
 #endif
 
 /**
@@ -239,38 +247,36 @@ extern const char bfs_ldlibs[];
  */
 #if __has_attribute(malloc)
 #  if __GNUC__ >= 11 && !__OPTIMIZE__ // malloc(deallocator) disables inlining on GCC
-#    define attr_malloc(...) attr_nodiscard __attribute__((malloc(__VA_ARGS__)))
+#    define _malloc(...) _nodiscard __attribute__((malloc(__VA_ARGS__)))
 #  else
-#    define attr_malloc(...) attr_nodiscard __attribute__((malloc))
+#    define _malloc(...) _nodiscard __attribute__((malloc))
 #  endif
 #else
-#  define attr_malloc(...) attr_nodiscard
+#  define _malloc(...) _nodiscard
 #endif
 
 /**
  * Specifies that a function returns allocations with a given alignment.
  */
 #if __has_attribute(alloc_align)
-#  define attr_alloc_align(param) __attribute__((alloc_align(param)))
+#  define _alloc_align(param) __attribute__((alloc_align(param)))
 #else
-#  define attr_alloc_align(param)
+#  define _alloc_align(param)
 #endif
 
 /**
  * Specifies that a function returns allocations with a given size.
  */
 #if __has_attribute(alloc_size)
-#  define attr_alloc_size(...) __attribute__((alloc_size(__VA_ARGS__)))
+#  define _alloc_size(...) __attribute__((alloc_size(__VA_ARGS__)))
 #else
-#  define attr_alloc_size(...)
+#  define _alloc_size(...)
 #endif
 
 /**
- * Shorthand for attr_alloc_align() and attr_alloc_size().
+ * Shorthand for _alloc_align() and _alloc_size().
  */
-#define attr_aligned_alloc(align, ...) \
-	attr_alloc_align(align) \
-	attr_alloc_size(__VA_ARGS__)
+#define _aligned_alloc(align, ...) _alloc_align(align) _alloc_size(__VA_ARGS__)
 
 /**
  * Check if function multiversioning via GNU indirect functions (ifunc) is supported.
@@ -285,83 +291,9 @@ extern const char bfs_ldlibs[];
  * Apply the target_clones attribute, if available.
  */
 #if BFS_USE_TARGET_CLONES
-#  define attr_target_clones(...) __attribute__((target_clones(__VA_ARGS__)))
+#  define _target_clones(...) __attribute__((target_clones(__VA_ARGS__)))
 #else
-#  define attr_target_clones(...)
+#  define _target_clones(...)
 #endif
 
-/**
- * Shorthand for multiple attributes at once. attr(a, b(c), d) is equivalent to
- *
- *     attr_a
- *     attr_b(c)
- *     attr_d
- */
-#define attr(...) \
-	attr__(attr_##__VA_ARGS__, none, none, none, none, none, none, none, none, none, )
-
-/**
- * attr() helper.  For exposition, pretend we support only 2 args, instead of 9.
- * There are a few cases:
- *
- *     attr()
- *         => attr__(attr_, none, none)
- *         => attr_                =>
- *            attr_none            =>
- *            attr_too_many_none() =>
- *
- *     attr(a)
- *         => attr__(attr_a, none, none)
- *         => attr_a               => __attribute__((a))
- *            attr_none            =>
- *            attr_too_many_none() =>
- *
- *     attr(a, b(c))
- *         => attr__(attr_a, b(c), none, none)
- *         => attr_a                   => __attribute__((a))
- *            attr_b(c)                => __attribute__((b(c)))
- *            attr_too_many_none(none) =>
- *
- *     attr(a, b(c), d)
- *         => attr__(attr_a, b(c), d, none, none)
- *         => attr_a                      => __attribute__((a))
- *            attr_b(c)                   => __attribute__((b(c)))
- *            attr_too_many_d(none, none) => error
- *
- * Some attribute names are the same as standard library functions, e.g. printf.
- * Standard libraries are permitted to define these functions as macros, like
- *
- *     #define printf(...) __builtin_printf(__VA_ARGS__)
- *
- * The token paste in
- *
- *     #define attr(...) attr__(attr_##__VA_ARGS__, none, none)
- *
- * is necessary to prevent macro expansion before evaluating attr__().
- * Otherwise, we could get
- *
- *     attr(printf(1, 2))
- *         => attr__(__builtin_printf(1, 2), none, none)
- *         => attr____builtin_printf(1, 2)
- *         => error
- */
-#define attr__(a1, a2, a3, a4, a5, a6, a7, a8, a9, none, ...) \
-	a1 \
-	attr_##a2 \
-	attr_##a3 \
-	attr_##a4 \
-	attr_##a5 \
-	attr_##a6 \
-	attr_##a7 \
-	attr_##a8 \
-	attr_##a9 \
-	attr_too_many_##none(__VA_ARGS__)
-
-// Ignore `attr_none` from expanding 1-9 argument attr(a1, a2, ...)
-#define attr_none
-// Ignore `attr_` from expanding 0-argument attr()
-#define attr_
-// Only trigger an error on more than 9 arguments
-#define attr_too_many_none(...)
-
 #endif // BFS_PRELUDE_H
diff --git a/src/printf.c b/src/printf.c
index 6b07c54..d09d1ec 100644
--- a/src/printf.c
+++ b/src/printf.c
@@ -89,7 +89,7 @@ static bool should_color(CFILE *cfile, const struct bfs_fmt *fmt) {
 	(void)ret
 
 /** Return a dynamic format string. */
-attr(format_arg(2))
+_format_arg(2)
 static const char *dyn_fmt(const char *str, const char *fake) {
 	bfs_assert(strcmp(str + strlen(str) - strlen(fake) + 1, fake + 1) == 0,
 		"Mismatched format specifiers: '%s' vs. '%s'", str, fake);
@@ -97,7 +97,7 @@ static const char *dyn_fmt(const char *str, const char *fake) {
 }
 
 /** Wrapper for fprintf(). */
-attr(printf(3, 4))
+_printf(3, 4)
 static int bfs_fprintf(CFILE *cfile, const struct bfs_fmt *fmt, const char *fake, ...) {
 	va_list args;
 	va_start(args, fake);
@@ -560,7 +560,7 @@ static int bfs_printf_Y(CFILE *cfile, const struct bfs_fmt *fmt, const struct BF
 }
 
 /** %Z: SELinux context */
-attr(maybe_unused)
+_maybe_unused
 static int bfs_printf_Z(CFILE *cfile, const struct bfs_fmt *fmt, const struct BFTW *ftwbuf) {
 	char *con = bfs_getfilecon(ftwbuf);
 	if (!con) {
diff --git a/src/sighook.c b/src/sighook.c
index ea58a0c..1b3bc43 100644
--- a/src/sighook.c
+++ b/src/sighook.c
@@ -366,7 +366,8 @@ static bool is_fatal(int sig) {
 }
 
 /** Reraise a fatal signal. */
-static noreturn void reraise(int sig) {
+_noreturn
+static void reraise(int sig) {
 	// Restore the default signal action
 	if (signal(sig, SIG_DFL) == SIG_ERR) {
 		goto fail;
diff --git a/src/trie.c b/src/trie.c
index cc5db09..e1c9f26 100644
--- a/src/trie.c
+++ b/src/trie.c
@@ -93,9 +93,9 @@
 bfs_static_assert(CHAR_WIDTH == 8);
 
 #if __i386__ || __x86_64__
-#  define trie_clones attr(target_clones("popcnt", "default"))
+#  define _trie_clones _target_clones("popcnt", "default")
 #else
-#  define trie_clones
+#  define _trie_clones
 #endif
 
 /** Number of bits for the sparse array bitmap, aka the range of a nibble. */
@@ -190,7 +190,7 @@ static unsigned char trie_key_nibble(const void *key, size_t offset) {
  * that case, the first mismatch between the key and the representative will be
  * the depth at which to make a new branch to insert the key.
  */
-trie_clones
+_trie_clones
 static struct trie_leaf *trie_representative(const struct trie *trie, const void *key, size_t length) {
 	uintptr_t ptr = trie->root;
 	if (!ptr) {
@@ -221,7 +221,7 @@ struct trie_leaf *trie_find_str(const struct trie *trie, const char *key) {
 	return trie_find_mem(trie, key, strlen(key) + 1);
 }
 
-trie_clones
+_trie_clones
 static struct trie_leaf *trie_find_mem_impl(const struct trie *trie, const void *key, size_t length) {
 	struct trie_leaf *rep = trie_representative(trie, key, length);
 	if (rep && rep->length == length && memcmp(rep->key, key, length) == 0) {
@@ -235,7 +235,7 @@ struct trie_leaf *trie_find_mem(const struct trie *trie, const void *key, size_t
 	return trie_find_mem_impl(trie, key, length);
 }
 
-trie_clones
+_trie_clones
 static struct trie_leaf *trie_find_postfix_impl(const struct trie *trie, const char *key) {
 	size_t length = strlen(key);
 	struct trie_leaf *rep = trie_representative(trie, key, length + 1);
@@ -280,7 +280,7 @@ static bool trie_check_prefix(struct trie_leaf *leaf, size_t skip, const char *k
 	}
 }
 
-trie_clones
+_trie_clones
 static struct trie_leaf *trie_find_prefix_impl(const struct trie *trie, const char *key) {
 	uintptr_t ptr = trie->root;
 	if (!ptr) {
@@ -438,7 +438,7 @@ static size_t trie_mismatch(const struct trie_leaf *rep, const void *key, size_t
  *      | Z
  *      +--->...
  */
-trie_clones
+_trie_clones
 static struct trie_leaf *trie_node_insert(struct trie *trie, uintptr_t *ptr, struct trie_leaf *leaf, unsigned char nibble) {
 	struct trie_node *node = trie_decode_node(*ptr);
 	unsigned int size = count_ones(node->bitmap);
@@ -561,7 +561,7 @@ struct trie_leaf *trie_insert_str(struct trie *trie, const char *key) {
 	return trie_insert_mem(trie, key, strlen(key) + 1);
 }
 
-trie_clones
+_trie_clones
 static struct trie_leaf *trie_insert_mem_impl(struct trie *trie, const void *key, size_t length) {
 	struct trie_leaf *rep = trie_representative(trie, key, length);
 	size_t mismatch = trie_mismatch(rep, key, length);
@@ -663,7 +663,7 @@ static int trie_collapse_node(struct trie *trie, uintptr_t *parent, struct trie_
 	return 0;
 }
 
-trie_clones
+_trie_clones
 static void trie_remove_impl(struct trie *trie, struct trie_leaf *leaf) {
 	uintptr_t *child = &trie->root;
 	uintptr_t *parent = NULL;
diff --git a/src/xspawn.c b/src/xspawn.c
index 8e6a727..30c9c40 100644
--- a/src/xspawn.c
+++ b/src/xspawn.c
@@ -103,7 +103,7 @@ int bfs_spawn_destroy(struct bfs_spawn *ctx) {
 
 #if _POSIX_SPAWN > 0
 /** Set some posix_spawnattr flags. */
-attr(maybe_unused)
+_maybe_unused
 static int bfs_spawn_addflags(struct bfs_spawn *ctx, short flags) {
 	short prev;
 	errno = posix_spawnattr_getflags(&ctx->attr, &prev);
@@ -519,7 +519,8 @@ static bool bfs_use_posix_spawn(const struct bfs_resolver *res, const struct bfs
 #endif // _POSIX_SPAWN > 0
 
 /** Actually exec() the new process. */
-static noreturn void bfs_spawn_exec(struct bfs_resolver *res, const struct bfs_spawn *ctx, char **argv, char **envp, int pipefd[2]) {
+_noreturn
+static void bfs_spawn_exec(struct bfs_resolver *res, const struct bfs_spawn *ctx, char **argv, char **envp, int pipefd[2]) {
 	xclose(pipefd[0]);
 
 	for_slist (const struct bfs_spawn_action, action, ctx) {