diff --git a/share/man/man9/style.9 b/share/man/man9/style.9 index 381f3aa3bfa3..daddc57bfb1f 100644 --- a/share/man/man9/style.9 +++ b/share/man/man9/style.9 @@ -1,936 +1,952 @@ .\"- .\" Copyright (c) 1995-2022 The FreeBSD Project .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL [your name] OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .Dd July 2, 2024 .Dt STYLE 9 .Os .Sh NAME .Nm style .Nd "kernel source file style guide" .Sh DESCRIPTION This file specifies the preferred style for kernel source files in the .Fx source tree. It is also a guide for the preferred userland code style. The preferred line width is 80 characters, but some exceptions are made when a slightly longer line is clearer or easier to read. Anything that is frequently grepped for, such as diagnostic, error, or panic messages, should not be broken up over multiple lines despite this rule. Many of the style rules are implicit in the examples. Be careful to check the examples before assuming that .Nm is silent on an issue. .Bd -literal /* * Style guide for FreeBSD. Based on the CSRG's KNF (Kernel Normal Form). */ /* * VERY important single-line comments look like this. */ /* Most single-line comments look like this. */ /* * Multi-line comments look like this. Make them real sentences. Fill * them so they look like real paragraphs. */ .Ed .Pp The copyright header should be a multi-line comment, with the first line of the comment having a dash after the star like so: .Bd -literal /*- * SPDX-License-Identifier: BSD-2-Clause * * Copyright (c) 1984-2025 John Q. Public * * Long, boring license goes here, but trimmed for brevity */ .Ed .Pp An automatic script collects license information from the tree for all comments that start in the first column with .Dq Li "/*-" . If you desire to flag .Xr indent 1 to not reformat a comment that starts in the first column which is not a license or copyright notice, change the dash to a star for those comments. Comments starting in columns other than the first are never considered license statements. Use the appropriate SPDX-License-Identifier line before the copyright. If the copyright assertion contains the phrase .Dq Li "All Rights Reserved" that should be on the same line as the word .Dq Li "Copyright" . You should not insert a new copyright line between an old copyright line and this phrase. Instead, you should insert a new copyright phrase after a pre-existing .Dq Li "All Rights Reserved" line. When making changes, it is acceptable to fold an .Dq Li "All Rights Reserved" line with each of the .Dq Li "Copyright" lines. For files that have the .Dq Li "All Rights Reserved" line on the same line(s) as the word .Dq Li "Copyright" , new copyright assertions should be added last. New .Dq Li "Copyright" lines should only be added when making substantial changes to the file, not for trivial changes. .Pp After any copyright and license comment, there is a blank line. Non-C/C++ source files follow the example above, while C/C++ source files follow the one below. Version control system ID tags should only exist once in a file (unlike in this one). All VCS (version control system) revision identification in files obtained from elsewhere should be maintained, including, where applicable, multiple IDs showing a file's history. In general, do not edit foreign IDs or their infrastructure. Unless otherwise wrapped (such as .Dq Li "#if defined(LIBC_SCCS)" ) , enclose both in .Dq Li "#if 0 ... #endif" to hide any uncompilable bits and to keep the IDs out of object files. Only add .Dq Li "From: " in front of foreign VCS IDs if the file is renamed. Add .Dq Li "From: " and FreeBSD git hash with full path name if the file was derived from another FreeBSD file and include relevant copyright info from the original file. .Bd -literal .Ed .Pp Leave one blank line before the header files. .Pp Kernel include files .Pa ( sys/*.h ) come first. If either .In sys/types.h or .In sys/param.h is needed, include it before other include files. .Po .In sys/param.h includes .In sys/types.h ; do not include both. .Pc Next, include .In sys/systm.h , if needed. The remaining kernel headers should be sorted alphabetically. .Bd -literal #include /* Non-local includes in angle brackets. */ #include #include #include #include .Ed .Pp For a network program, put the network include files next. .Bd -literal #include #include #include #include #include .Ed .Pp Do not include files from .Pa /usr/include in the kernel. .Pp Leave a blank line before the next group, the .Pa /usr/include files, which should be sorted alphabetically by name. .Bd -literal #include .Ed .Pp Global pathnames are defined in .In paths.h . Pathnames local to the program go in .Qq Pa pathnames.h in the local directory. .Bd -literal #include .Ed .Pp Leave another blank line before the local include files. .Bd -literal #include "pathnames.h" /* Local includes in double quotes. */ .Ed .Pp Do not .Ic #define or declare names in the implementation namespace except for implementing application interfaces. .Pp The names of .Dq unsafe macros (ones that have side effects), and the names of macros for manifest constants, are all in uppercase. The expansions of expression-like macros are either a single token or have outer parentheses. Put a single space or tab character between the .Ic #define and the macro name, but be consistent within a file. If a macro is an inline expansion of a function, the function name is all in lowercase and the macro has the same name all in uppercase. .\" XXX the above conflicts with ANSI style where the names are the .\" same and you #undef the macro (if any) to get the function. .\" It is not followed for MALLOC(), and not very common if inline .\" functions are used. Right-justify the backslashes; it makes it easier to read. If the macro encapsulates a compound statement, enclose it in a .Ic do loop, so that it can safely be used in .Ic if statements. Any final statement-terminating semicolon should be supplied by the macro invocation rather than the macro, to make parsing easier for pretty-printers and editors. .Bd -literal #define MACRO(x, y) do { \e variable = (x) + (y); \e (y) += 2; \e } while (0) .Ed .Pp When code is conditionally compiled using .Ic #ifdef or .Ic #if , a comment may be added following the matching .Ic #endif or .Ic #else to permit the reader to easily discern where conditionally compiled code regions end. This comment should be used only for (subjectively) long regions, regions greater than 20 lines, or where a series of nested .Ic #ifdef 's may be confusing to the reader. The comment should be separated from the .Ic #endif or .Ic #else by a single space. For short conditionally compiled regions, a closing comment should not be used. .Pp The comment for .Ic #endif should match the expression used in the corresponding .Ic #if or .Ic #ifdef . The comment for .Ic #else and .Ic #elif should match the inverse of the expression(s) used in the preceding .Ic #if and/or .Ic #elif statements. In the comments, the subexpression .Dq Li defined(FOO) is abbreviated as .Dq Li FOO . For the purposes of comments, .Dq Ic #ifndef Li FOO is treated as .Dq Ic #if Li !defined(FOO) . .Bd -literal #ifdef KTRACE #include #endif #ifdef COMPAT_43 /* A large region here, or other conditional code. */ #else /* !COMPAT_43 */ /* Or here. */ #endif /* COMPAT_43 */ #ifndef COMPAT_43 /* Yet another large region here, or other conditional code. */ #else /* COMPAT_43 */ /* Or here. */ #endif /* !COMPAT_43 */ .Ed .Pp The project prefers the use of .St -isoC-99 unsigned integer identifiers of the form .Vt uintXX_t rather than the older .Bx Ns -style integer identifiers of the form .Vt u_intXX_t . New code should use the former, and old code should be converted to the new form if other major work is being done in that area and there is no overriding reason to prefer the older .Bx Ns -style . Like white-space commits, care should be taken in making .Vt uintXX_t only commits. .Pp Similarly, the project prefers the use of ISO C99 .Vt bool rather than the older .Vt int or .Vt boolean_t . New code should use .Vt bool , and old code may be converted if it is reasonable to do so. Literal values are named .Dv true and .Dv false . These are preferred to the old spellings .Dv TRUE and .Dv FALSE . Userspace code should include .In stdbool.h , while kernel code should include .In sys/types.h . .Pp Likewise, the project prefers ISO C99 designated initializers when it makes sense to do so. .Pp Enumeration values are all uppercase. .Bd -literal enum enumtype { ONE, TWO } et; .Ed .Pp The use of internal_underscores in identifiers is preferred over camelCase or TitleCase. .Pp In declarations, do not put any whitespace between asterisks and adjacent tokens, except for tokens that are identifiers related to types. (These identifiers are the names of basic types, type qualifiers, and .Ic typedef Ns -names other than the one being declared.) Separate these identifiers from asterisks using a single space. .Pp When declaring variables in structures, declare them sorted by use, then by size (largest to smallest), and then in alphabetical order. The first category normally does not apply, but there are exceptions. Each one gets its own line. Try to make the structure readable by aligning the member names using either one or two tabs depending upon your judgment. You should use one tab only if it suffices to align at least 90% of the member names. Names following extremely long types should be separated by a single space. .Pp Major structures should be declared at the top of the file in which they are used, or in separate header files if they are used in multiple source files. Use of the structures should be by separate declarations and should be .Ic extern if they are declared in a header file. .Bd -literal struct foo { struct foo *next; /* List of active foo. */ struct mumble amumble; /* Comment for mumble. */ int bar; /* Try to align the comments. */ struct verylongtypename *baz; /* Does not fit in 2 tabs. */ }; struct foo *foohead; /* Head of global foo list. */ .Ed .Pp Use .Xr queue 3 macros rather than rolling your own lists, whenever possible. Thus, the previous example would be better written: .Bd -literal #include struct foo { LIST_ENTRY(foo) link; /* Use queue macros for foo lists. */ struct mumble amumble; /* Comment for mumble. */ int bar; /* Try to align the comments. */ struct verylongtypename *baz; /* Does not fit in 2 tabs. */ }; LIST_HEAD(, foo) foohead; /* Head of global foo list. */ .Ed .Pp Avoid using typedefs for structure types. Typedefs are problematic because they do not properly hide their underlying type; for example you need to know if the typedef is the structure itself or a pointer to the structure. In addition they must be declared exactly once, whereas an incomplete structure type can be mentioned as many times as necessary. Typedefs are difficult to use in stand-alone header files: the header that defines the typedef must be included before the header that uses it, or by the header that uses it (which causes namespace pollution), or there must be a back-door mechanism for obtaining the typedef. .Pp When convention requires a .Ic typedef , make its name match the struct tag. Avoid typedefs ending in .Dq Li _t , except as specified in Standard C or by POSIX. .Bd -literal /* Make the structure name match the typedef. */ typedef struct bar { int level; } BAR; typedef int foo; /* This is foo. */ typedef const long baz; /* This is baz. */ .Ed .Pp All functions are prototyped somewhere. .Pp Function prototypes for private functions (i.e., functions not used elsewhere) go at the top of the first source module. Functions local to one source module should be declared .Ic static . .Pp Functions used from other parts of the kernel are prototyped in the relevant include file. Function prototypes should be listed in a logical order, preferably alphabetical unless there is a compelling reason to use a different ordering. .Pp Functions that are used locally in more than one module go into a separate header file, e.g., .Qq Pa extern.h . .Pp In general code can be considered .Dq "new code" when it makes up about 50% or more of the file(s) involved. This is enough to break precedents in the existing code and use the current .Nm guidelines. .Pp The kernel has a name associated with parameter types, e.g., in the kernel use: .Bd -literal void function(int fd); .Ed .Pp In header files visible to userland applications, prototypes that are visible must use either .Dq protected names (ones beginning with an underscore) or no names with the types. It is preferable to use protected names. E.g., use: .Bd -literal void function(int); .Ed .Pp or: .Bd -literal void function(int _fd); .Ed .Pp Prototypes may have an extra space after a tab to enable function names to line up: .Bd -literal static char *function(int _arg, const char *_arg2, struct foo *_arg3, struct bar *_arg4); static void usage(void); /* * All major routines should have a comment briefly describing what * they do. The comment before the "main" routine should describe * what the program does. */ int main(int argc, char *argv[]) { char *ep; long num; int ch; .Ed .Pp For consistency, .Xr getopt 3 should be used to parse options. Options should be sorted in the .Xr getopt 3 call and the .Ic switch statement, unless parts of the .Ic switch cascade. Elements in a .Ic switch statement that cascade should have a .Li FALLTHROUGH comment. Numerical arguments should be checked for accuracy. Code which is unreachable for non-obvious reasons may be marked /* .Li NOTREACHED */. .Bd -literal while ((ch = getopt(argc, argv, "abNn:")) != -1) switch (ch) { /* Indent the switch. */ case 'a': /* Do not indent the case. */ aflag = 1; /* Indent case body one tab. */ /* FALLTHROUGH */ case 'b': bflag = 1; break; case 'N': Nflag = 1; break; case 'n': num = strtol(optarg, &ep, 10); if (num <= 0 || *ep != '\e0') { warnx("illegal number, -n argument -- %s", optarg); usage(); } break; case '?': default: usage(); } argc -= optind; argv += optind; .Ed .Pp Space after keywords .Pq Ic if , while , for , return , switch . Two styles of braces .Ql ( \&{ and .Ql \&} ) are allowed for single line statements. Either they are used for all single statements, or they are used only where needed for clarity. Usage within a function should be consistent. Forever loops are done with .Ic for Ns 's , not .Ic while Ns 's . .Bd -literal for (p = buf; *p != '\e0'; ++p) ; /* nothing */ for (;;) stmt; for (;;) { z = a + really + long + statement + that + needs + two + lines + gets + indented + four + spaces + on + the + second + and + subsequent + lines; } for (;;) { if (cond) stmt; } if (val != NULL) val = realloc(val, newsize); .Ed .Pp Parts of a .Ic for loop may be left empty. .Bd -literal for (; cnt < 15; cnt++) { stmt1; stmt2; } .Ed .Pp A .Ic for loop may declare and initialize its counting variable. .Bd -literal for (int i = 0; i < 15; i++) { stmt1; } .Ed .Pp Indentation is an 8 character tab. Second level indents are four spaces. If you have to wrap a long statement, put the operator at the end of the line. .Bd -literal while (cnt < 20 && this_variable_name_is_too_long && ep != NULL) z = a + really + long + statement + that + needs + two + lines + gets + indented + four + spaces + on + the + second + and + subsequent + lines; .Ed .Pp Do not add whitespace at the end of a line, and only use tabs followed by spaces to form the indentation. Do not use more spaces than a tab will produce and do not use spaces in front of tabs. .Pp Closing and opening braces go on the same line as the .Ic else . Braces that are not necessary may be left out. .Bd -literal if (test) stmt; else if (bar) { stmt; stmt; } else stmt; .Ed .Pp No spaces after function names. Commas have a space after them. No spaces after .Ql \&( or .Ql \&[ or preceding .Ql \&] or .Ql \&) characters. .Bd -literal error = function(a1, a2); if (error != 0) exit(error); .Ed .Pp Unary operators do not require spaces, binary operators do. Do not use parentheses unless they are required for precedence or unless the statement is confusing without them. Remember that other people may confuse easier than you. Do YOU understand the following? .Bd -literal a = b->c[0] + ~d == (e || f) || g && h ? i : j >> 1; k = !(l & FLAGS); .Ed .Pp Exits should be 0 on success, or 1 on failure. .Bd -literal exit(0); /* * Avoid obvious comments such as * "Exit 0 on success." */ } .Ed .Pp The function type should be on a line by itself preceding the function. The opening brace of the function body should be on a line by itself. .Bd -literal static char * function(int a1, int a2, float fl, int a4, struct bar *bar) { .Ed .Pp When declaring variables in functions declare them sorted by size, then in alphabetical order; multiple ones per line are okay. If a line overflows reuse the type keyword. Variables may be initialized where declared especially when they are constant for the rest of the scope. Declarations may be in any block, but must be placed before statements. Calls to complicated functions should be avoided when initializing variables. .Bd -literal struct foo one, *two; struct baz *three = bar_get_baz(bar); double four; int *five, six; char *seven, eight, nine, ten, eleven, twelve; four = my_complicated_function(a1, f1, a4); .Ed .Pp Do not declare functions inside other functions; ANSI C says that such declarations have file scope regardless of the nesting of the declaration. Hiding file declarations in what appears to be a local scope is undesirable and will elicit complaints from a good compiler. .Pp Casts and .Ic sizeof Ns 's are not followed by a space. .Ic sizeof Ns 's are written with parenthesis always. The redundant parenthesis rules do not apply to .Fn sizeof var instances. .Pp .Dv NULL is the preferred null pointer constant. Use .Dv NULL instead of .Vt ( "type *" ) Ns 0 or .Vt ( "type *" ) Ns Dv NULL in contexts where the compiler knows the type, e.g., in assignments. Use .Vt ( "type *" ) Ns Dv NULL in other contexts, in particular for all function args. (Casting is essential for variadic args and is necessary for other args if the function prototype might not be in scope.) Test pointers against .Dv NULL , e.g., use: .Bd -literal (p = f()) == NULL .Ed .Pp not: .Bd -literal !(p = f()) .Ed .Pp Do not use .Ic \&! for tests unless it is a boolean, e.g., use: .Bd -literal if (*p == '\e0') .Ed .Pp not: .Bd -literal if (!*p) .Ed .Pp Routines returning .Vt "void *" should not have their return values cast to any pointer type. .Pp Values in .Ic return statements should be enclosed in parentheses. .Pp Use .Xr err 3 or .Xr warn 3 , do not roll your own. .Bd -literal if ((four = malloc(sizeof(struct foo))) == NULL) err(1, (char *)NULL); if ((six = (int *)overflow()) == NULL) errx(1, "number overflowed"); return (eight); } .Ed .Pp Do not use K&R style declarations or definitions, they are obsolete and are forbidden in C23. Compilers warn of their use and some treat them as an error by default. When converting K&R style definitions to ANSI style, preserve any comments about parameters. .Pp Long parameter lists are wrapped with a normal four space indent. .Pp Variable numbers of arguments should look like this: .Bd -literal #include void vaf(const char *fmt, ...) { va_list ap; va_start(ap, fmt); STUFF; va_end(ap); /* No return needed for void functions. */ } static void usage(void) { /* Optional blank line goes here. */ .Ed .Pp Optionally, insert a blank line at the beginning of functions with no local variables. Older versions of this .Nm document required the blank line convention, so it is widely used in existing code. .Pp Do not insert a blank line at the beginning of functions with local variables. Instead, these should have local variable declarations first, followed by one blank line, followed by the first statement. .Pp Use .Xr printf 3 , not .Xr fputs 3 , .Xr puts 3 , .Xr putchar 3 , whatever; it is faster and usually cleaner, not to mention avoiding stupid bugs. .Pp Usage statements should look like the manual pages .Sx SYNOPSIS . The usage statement should be structured in the following order: .Bl -enum .It Options without operands come first, in alphabetical order, inside a single set of brackets .Ql ( \&[ and .Ql \&] ) . .It Options with operands come next, also in alphabetical order, with each option and its argument inside its own pair of brackets. .It Required arguments (if any) are next, listed in the order they should be specified on the command line. .It Finally, any optional arguments should be listed, listed in the order they should be specified, and all inside brackets. .El .Pp A bar .Pq Ql \&| separates .Dq either-or options/arguments, and multiple options/arguments which are specified together are placed in a single set of brackets. .Bd -literal -offset 4n "usage: f [-aDde] [-b b_arg] [-m m_arg] req1 req2 [opt1 [opt2]]\en" "usage: f [-a | -b] [-c [-dEe] [-n number]]\en" .Ed .Bd -literal (void)fprintf(stderr, "usage: f [-ab]\en"); exit(1); } .Ed .Pp Note that the manual page options description should list the options in pure alphabetical order. That is, without regard to whether an option takes arguments or not. The alphabetical ordering should take into account the case ordering shown above. .Pp New core kernel code should be reasonably compliant with the .Nm guides. The guidelines for third-party maintained modules and device drivers are more relaxed but at a minimum should be internally consistent with their style. .Pp Stylistic changes (including whitespace changes) are hard on the source repository and are to be avoided without good reason. Code that is approximately .Fx KNF .Nm compliant in the repository must not diverge from compliance. .Pp Whenever possible, code should be run through a code checker (e.g., various static analyzers or .Nm cc Fl Wall ) and produce minimal warnings. .Pp New code should use .Fn _Static_assert instead of the older .Fn CTASSERT . +.Pp +.Fn __predict_true +and +.Fn __predict_false +should only be used in frequently executed code when it makes the code +measurably faster. +It is wasteful to make predictions for infrequently run code, like subsystem +initialization. +When using branch prediction hints, atypical error conditions should use +.Fn __predict_false +(document the exceptions). +Operations that almost always succeed use +.Fn __predict_true . +Only use the annotation for the entire if statement, rather than individual clauses. +Do not add these annotations without empirical evidence of the likelihood of the +branch. .Sh FILES .Bl -tag -width indent .It Pa /usr/src/tools/build/checkstyle9.pl A script to check for violations of .Nm in a source file. .It Pa /usr/src/tools/tools/editing/freebsd.el An Emacs plugin to follow the .Fx .Nm indentation rules. .It Pa /usr/src/tools/tools/editing/freebsd.vim A Vim plugin to follow the .Fx .Nm indentation rules. .El .Sh SEE ALSO .Xr indent 1 , .Xr err 3 , .Xr warn 3 , .Xr style.Makefile 5 , .Xr style.mdoc 5 , .Xr style.lua 9 .Sh HISTORY This manual page was originally based on the .Pa src/admin/style/style file from the .Bx 4.4 Lite2 release, with frequent updates to reflect the current practice and desire of the .Fx project. .Pa src/admin/style/style is a codification by the CSRG of the programming style of Ken Thompson and Dennis Ritchie in .At v6 . diff --git a/sys/sys/cdefs.h b/sys/sys/cdefs.h index 7c4890ece8d5..b92992c1b5c3 100644 --- a/sys/sys/cdefs.h +++ b/sys/sys/cdefs.h @@ -1,762 +1,769 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1991, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Berkeley Software Design, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #ifndef _SYS_CDEFS_H_ #define _SYS_CDEFS_H_ #if defined(_KERNEL) && defined(_STANDALONE) #error "_KERNEL and _STANDALONE are mutually exclusive" #endif /* * Provide clang-compatible testing macros. All supported versions of gcc (10+) * provide all of these except has_feature and has_extension which are new in * gcc 14. Keep the older ifndefs, though, for non-gcc compilers that may lack * them like tcc and pcc. */ #ifndef __has_attribute #define __has_attribute(x) 0 #endif #ifndef __has_extension #define __has_extension __has_feature #endif #ifndef __has_feature #define __has_feature(x) 0 #endif #ifndef __has_include #define __has_include(x) 0 #endif #ifndef __has_builtin #define __has_builtin(x) 0 #endif #if defined(__cplusplus) #define __BEGIN_DECLS extern "C" { #define __END_DECLS } #else #define __BEGIN_DECLS #define __END_DECLS #endif /* * This code has been put in place to help reduce the addition of * compiler specific defines in FreeBSD code. It helps to aid in * having a compiler-agnostic source tree. */ /* * Macro to test if we're using a specific version of gcc or later. */ #if defined(__GNUC__) #define __GNUC_PREREQ__(ma, mi) \ (__GNUC__ > (ma) || __GNUC__ == (ma) && __GNUC_MINOR__ >= (mi)) #else #define __GNUC_PREREQ__(ma, mi) 0 #endif #if defined(__GNUC__) /* * Compiler memory barriers, specific to gcc and clang. */ #define __compiler_membar() __asm __volatile(" " : : : "memory") #define __CC_SUPPORTS___INLINE 1 #define __CC_SUPPORTS_SYMVER 1 #endif /* __GNUC__ */ /* * TinyC pretends to be gcc 9.3. This is generally good enough to support * everything FreeBSD... except for the .symver assembler directive. */ #ifdef __TINYC__ #undef __CC_SUPPORTS_SYMVER #endif /* * The __CONCAT macro is used to concatenate parts of symbol names, e.g. * with "#define OLD(foo) __CONCAT(old,foo)", OLD(foo) produces oldfoo. * The __CONCAT macro is a bit tricky to use if it must work in non-ANSI * mode -- there must be no spaces between its arguments, and for nested * __CONCAT's, all the __CONCAT's must be at the left. __CONCAT can also * concatenate double-quoted strings produced by the __STRING macro, but * this only works with ANSI C. * * __XSTRING is like __STRING, but it expands any macros in its argument * first. It is only available with ANSI C. */ #if defined(__STDC__) || defined(__cplusplus) #define __P(protos) protos /* full-blown ANSI C */ #define __CONCAT1(x,y) x ## y #define __CONCAT(x,y) __CONCAT1(x,y) #define __STRING(x) #x /* stringify without expanding x */ #define __XSTRING(x) __STRING(x) /* expand x, then stringify */ #define __const const /* define reserved names to standard */ #define __signed signed #define __volatile volatile #if defined(__cplusplus) #define __inline inline /* convert to C++ keyword */ #else #if !(defined(__CC_SUPPORTS___INLINE)) #define __inline /* delete GCC keyword */ #endif /* ! __CC_SUPPORTS___INLINE */ #endif /* !__cplusplus */ #else /* !(__STDC__ || __cplusplus) */ #define __P(protos) () /* traditional C preprocessor */ #define __CONCAT(x,y) x/**/y #define __STRING(x) "x" #if !defined(__CC_SUPPORTS___INLINE) #define __const /* delete pseudo-ANSI C keywords */ #define __inline #define __signed #define __volatile /* * In non-ANSI C environments, new programs will want ANSI-only C keywords * deleted from the program and old programs will want them left alone. * When using a compiler other than gcc, programs using the ANSI C keywords * const, inline etc. as normal identifiers should define -DNO_ANSI_KEYWORDS. * When using "gcc -traditional", we assume that this is the intent; if * __GNUC__ is defined but __STDC__ is not, we leave the new keywords alone. */ #ifndef NO_ANSI_KEYWORDS #define const /* delete ANSI C keywords */ #define inline #define signed #define volatile #endif /* !NO_ANSI_KEYWORDS */ #endif /* !__CC_SUPPORTS___INLINE */ #endif /* !(__STDC__ || __cplusplus) */ /* * Compiler-dependent macros to help declare dead (non-returning) and pure (no * side effects) functions, and unused variables. These attributes are supported * by all current compilers, even pcc. */ #define __weak_symbol __attribute__((__weak__)) #define __dead2 __attribute__((__noreturn__)) #define __pure2 __attribute__((__const__)) #define __unused __attribute__((__unused__)) #define __used __attribute__((__used__)) #define __packed __attribute__((__packed__)) #define __aligned(x) __attribute__((__aligned__(x))) #define __section(x) __attribute__((__section__(x))) #define __writeonly __unused #define __alloc_size(x) __attribute__((__alloc_size__(x))) #define __alloc_size2(n, x) __attribute__((__alloc_size__(n, x))) #define __alloc_align(x) __attribute__((__alloc_align__(x))) /* * Keywords added in C11. */ #if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 201112L #if !__has_extension(c_alignas) #if (defined(__cplusplus) && __cplusplus >= 201103L) || \ __has_extension(cxx_alignas) #define _Alignas(x) alignas(x) #else /* XXX: Only emulates _Alignas(constant-expression); not _Alignas(type-name). */ #define _Alignas(x) __aligned(x) #endif #endif #if defined(__cplusplus) && __cplusplus >= 201103L #define _Alignof(x) alignof(x) #else #define _Alignof(x) __alignof(x) #endif #if defined(__cplusplus) && __cplusplus >= 201103L #define _Noreturn [[noreturn]] #else #define _Noreturn __dead2 #endif #if !__has_extension(c_static_assert) #if (defined(__cplusplus) && __cplusplus >= 201103L) || \ __has_extension(cxx_static_assert) #define _Static_assert(x, y) static_assert(x, y) #endif #endif #if !__has_extension(c_thread_local) #if (defined(__cplusplus) && __cplusplus >= 201103L) || \ __has_extension(cxx_thread_local) #define _Thread_local thread_local #else #define _Thread_local __thread #endif #endif #endif /* __STDC_VERSION__ || __STDC_VERSION__ < 201112L */ /* * Emulation of C11 _Generic(). Unlike the previously defined C11 * keywords, it is not possible to implement this using exactly the same * syntax. Therefore implement something similar under the name * __generic(). Unlike _Generic(), this macro can only distinguish * between a single type, so it requires nested invocations to * distinguish multiple cases. * * Note that the comma operator is used to force expr to decay in * order to match _Generic(). */ #if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L) || \ __has_extension(c_generic_selections) #define __generic(expr, t, yes, no) \ _Generic(expr, t: yes, default: no) #elif !defined(__cplusplus) #define __generic(expr, t, yes, no) \ __builtin_choose_expr(__builtin_types_compatible_p( \ __typeof(((void)0, (expr))), t), yes, no) #endif /* * C99 Static array indices in function parameter declarations. Syntax such as: * void bar(int myArray[static 10]); * is allowed in C99 but not in C++. Define __min_size appropriately so * headers using it can be compiled in either language. Use like this: * void bar(int myArray[__min_size(10)]); */ #if !defined(__cplusplus) && \ (!defined(__STDC_VERSION__) || (__STDC_VERSION__ >= 199901)) #define __min_size(x) static (x) #else #define __min_size(x) (x) #endif #define __malloc_like __attribute__((__malloc__)) #define __pure __attribute__((__pure__)) #define __always_inline __inline __attribute__((__always_inline__)) #define __noinline __attribute__ ((__noinline__)) #define __fastcall __attribute__((__fastcall__)) #define __result_use_check __attribute__((__warn_unused_result__)) #ifdef __clang__ /* * clang and gcc have different semantics for __warn_unused_result__: the latter * does not permit the use of a void cast to suppress the warning. Use * __result_use_or_ignore_check in places where a void cast is acceptable. * This can be implemented by [[nodiscard]] from C23. */ #define __result_use_or_ignore_check __result_use_check #else #define __result_use_or_ignore_check #endif /* !__clang__ */ #define __returns_twice __attribute__((__returns_twice__)) #define __unreachable() __builtin_unreachable() #if !defined(__STRICT_ANSI__) || __STDC_VERSION__ >= 199901 #define __LONG_LONG_SUPPORTED #endif /* C++11 exposes a load of C99 stuff */ #if defined(__cplusplus) && __cplusplus >= 201103L #define __LONG_LONG_SUPPORTED #ifndef __STDC_LIMIT_MACROS #define __STDC_LIMIT_MACROS #endif #ifndef __STDC_CONSTANT_MACROS #define __STDC_CONSTANT_MACROS #endif #endif /* * noexcept keyword added in C++11. */ #if defined(__cplusplus) && __cplusplus >= 201103L #define __noexcept noexcept #define __noexcept_if(__c) noexcept(__c) #else #define __noexcept #define __noexcept_if(__c) #endif /* * We use `__restrict' as a way to define the `restrict' type qualifier * without disturbing older software that is unaware of C99 keywords. * GCC also provides `__restrict' as an extension to support C99-style * restricted pointers in other language modes. */ #if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901 #define __restrict restrict #endif +/* + * All modern compilers have explicit branch prediction so that the CPU back-end + * can hint to the processor and also so that code blocks can be reordered such + * that the predicted path sees a more linear flow, thus improving cache + * behavior, etc. Use sparingly, except in performance critical code where + * they make things measurably faster. + */ #define __predict_true(exp) __builtin_expect((exp), 1) #define __predict_false(exp) __builtin_expect((exp), 0) #define __null_sentinel __attribute__((__sentinel__)) #define __exported __attribute__((__visibility__("default"))) #define __hidden __attribute__((__visibility__("hidden"))) /* * We define this here since , , and * require it. */ #define __offsetof(type, field) __builtin_offsetof(type, field) #define __rangeof(type, start, end) \ (__offsetof(type, end) - __offsetof(type, start)) /* * Given the pointer x to the member m of the struct s, return * a pointer to the containing structure. When using GCC, we first * assign pointer x to a local variable, to check that its type is * compatible with member m. */ #define __containerof(x, s, m) ({ \ const volatile __typeof(((s *)0)->m) *__x = (x); \ __DEQUALIFY(s *, (const volatile char *)__x - __offsetof(s, m));\ }) /* * Compiler-dependent macros to declare that functions take printf-like * or scanf-like arguments. They are null except for versions of gcc * that are known to support the features properly (old versions of gcc-2 * didn't permit keeping the keywords out of the application namespace). */ #define __printflike(fmtarg, firstvararg) \ __attribute__((__format__ (__printf__, fmtarg, firstvararg))) #define __scanflike(fmtarg, firstvararg) \ __attribute__((__format__ (__scanf__, fmtarg, firstvararg))) #define __format_arg(fmtarg) __attribute__((__format_arg__ (fmtarg))) #define __strfmonlike(fmtarg, firstvararg) \ __attribute__((__format__ (__strfmon__, fmtarg, firstvararg))) #define __strftimelike(fmtarg, firstvararg) \ __attribute__((__format__ (__strftime__, fmtarg, firstvararg))) #define __printf0like(fmtarg, firstvararg) \ __attribute__((__format__ (__printf0__, fmtarg, firstvararg))) #define __strong_reference(sym,aliassym) \ extern __typeof (sym) aliassym __attribute__ ((__alias__ (#sym))) #ifdef __STDC__ #define __weak_reference(sym,alias) \ __asm__(".weak " #alias); \ __asm__(".equ " #alias ", " #sym) #define __warn_references(sym,msg) \ __asm__(".section .gnu.warning." #sym); \ __asm__(".asciz \"" msg "\""); \ __asm__(".previous") #ifdef __CC_SUPPORTS_SYMVER #define __sym_compat(sym,impl,verid) \ __asm__(".symver " #impl ", " #sym "@" #verid) #define __sym_default(sym,impl,verid) \ __asm__(".symver " #impl ", " #sym "@@@" #verid) #endif #else #define __weak_reference(sym,alias) \ __asm__(".weak alias"); \ __asm__(".equ alias, sym") #define __warn_references(sym,msg) \ __asm__(".section .gnu.warning.sym"); \ __asm__(".asciz \"msg\""); \ __asm__(".previous") #ifdef __CC_SUPPORTS_SYMVER #define __sym_compat(sym,impl,verid) \ __asm__(".symver impl, sym@verid") #define __sym_default(impl,sym,verid) \ __asm__(".symver impl, sym@@@verid") #endif #endif /* __STDC__ */ #define __GLOBL(sym) __asm__(".globl " __XSTRING(sym)) #define __WEAK(sym) __asm__(".weak " __XSTRING(sym)) #define __IDSTRING(name,string) __asm__(".ident\t\"" string "\"") /* * Embed the rcs id of a source file in the resulting library. Note that in * more recent ELF binutils, we use .ident allowing the ID to be stripped. * Usage: */ #ifndef __FBSDID #if !defined(STRIP_FBSDID) #define __FBSDID(s) __IDSTRING(__CONCAT(__rcsid_,__LINE__),s) #else #define __FBSDID(s) struct __hack #endif #endif #ifndef __RCSID #ifndef NO__RCSID #define __RCSID(s) __IDSTRING(__CONCAT(__rcsid_,__LINE__),s) #else #define __RCSID(s) struct __hack #endif #endif #ifndef __RCSID_SOURCE #ifndef NO__RCSID_SOURCE #define __RCSID_SOURCE(s) __IDSTRING(__CONCAT(__rcsid_source_,__LINE__),s) #else #define __RCSID_SOURCE(s) struct __hack #endif #endif #ifndef __SCCSID #ifndef NO__SCCSID #define __SCCSID(s) __IDSTRING(__CONCAT(__sccsid_,__LINE__),s) #else #define __SCCSID(s) struct __hack #endif #endif #ifndef __COPYRIGHT #ifndef NO__COPYRIGHT #define __COPYRIGHT(s) __IDSTRING(__CONCAT(__copyright_,__LINE__),s) #else #define __COPYRIGHT(s) struct __hack #endif #endif #ifndef __DECONST #define __DECONST(type, var) ((type)(__uintptr_t)(const void *)(var)) #endif #ifndef __DEVOLATILE #define __DEVOLATILE(type, var) ((type)(__uintptr_t)(volatile void *)(var)) #endif #ifndef __DEQUALIFY #define __DEQUALIFY(type, var) ((type)(__uintptr_t)(const volatile void *)(var)) #endif #if !defined(_STANDALONE) && !defined(_KERNEL) #define __RENAME(x) __asm(__STRING(x)) #else /* _STANDALONE || _KERNEL */ #define __RENAME(x) no renaming in kernel/standalone environment #endif /*- * The following definitions are an extension of the behavior originally * implemented in , but with a different level of granularity. * POSIX.1 requires that the macros we test be defined before any standard * header file is included. * * Here's a quick run-down of the versions (and some informal names) * defined(_POSIX_SOURCE) 1003.1-1988 * encoded as 198808 below * _POSIX_C_SOURCE == 1 1003.1-1990 * encoded as 199009 below * _POSIX_C_SOURCE == 2 1003.2-1992 C Language Binding Option * encoded as 199209 below * _POSIX_C_SOURCE == 199309 1003.1b-1993 * (1003.1 Issue 4, Single Unix Spec v1, Unix 93) * _POSIX_C_SOURCE == 199506 1003.1c-1995, 1003.1i-1995, * and the omnibus ISO/IEC 9945-1: 1996 * (1003.1 Issue 5, Single Unix Spec v2, Unix 95) * _POSIX_C_SOURCE == 200112 1003.1-2001 (1003.1 Issue 6, Unix 03) * with _XOPEN_SOURCE=600 * _POSIX_C_SOURCE == 200809 1003.1-2008 (1003.1 Issue 7) * IEEE Std 1003.1-2017 (Rev of 1003.1-2008) is * 1003.1-2008 with two TCs applied and * _XOPEN_SOURCE=700 * _POSIX_C_SOURCE == 202405 1003.1-2004 (1003.1 Issue 8), IEEE Std 1003.1-2024 * with _XOPEN_SOURCE=800 * * In addition, the X/Open Portability Guide, which is now the Single UNIX * Specification, defines a feature-test macro which indicates the version of * that specification, and which subsumes _POSIX_C_SOURCE. * * Our macros begin with two underscores to avoid namespace screwage. */ /* Deal with IEEE Std. 1003.1-1990, in which _POSIX_C_SOURCE == 1. */ #if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE == 1 #undef _POSIX_C_SOURCE /* Probably illegal, but beyond caring now. */ #define _POSIX_C_SOURCE 199009 #endif /* Deal with IEEE Std. 1003.2-1992, in which _POSIX_C_SOURCE == 2. */ #if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE == 2 #undef _POSIX_C_SOURCE #define _POSIX_C_SOURCE 199209 #endif /* Deal with various X/Open Portability Guides and Single UNIX Spec. */ #ifdef _XOPEN_SOURCE #if _XOPEN_SOURCE - 0 >= 700 #define __XSI_VISIBLE 700 #undef _POSIX_C_SOURCE #define _POSIX_C_SOURCE 200809 #elif _XOPEN_SOURCE - 0 >= 600 #define __XSI_VISIBLE 600 #undef _POSIX_C_SOURCE #define _POSIX_C_SOURCE 200112 #elif _XOPEN_SOURCE - 0 >= 500 #define __XSI_VISIBLE 500 #undef _POSIX_C_SOURCE #define _POSIX_C_SOURCE 199506 #endif #endif /* * Deal with all versions of POSIX. The ordering relative to the tests above is * important. */ #if defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE) #define _POSIX_C_SOURCE 198808 #endif #ifdef _POSIX_C_SOURCE #if _POSIX_C_SOURCE >= 200809 #define __POSIX_VISIBLE 200809 #define __ISO_C_VISIBLE 1999 #elif _POSIX_C_SOURCE >= 200112 #define __POSIX_VISIBLE 200112 #define __ISO_C_VISIBLE 1999 #elif _POSIX_C_SOURCE >= 199506 #define __POSIX_VISIBLE 199506 #define __ISO_C_VISIBLE 1990 #elif _POSIX_C_SOURCE >= 199309 #define __POSIX_VISIBLE 199309 #define __ISO_C_VISIBLE 1990 #elif _POSIX_C_SOURCE >= 199209 #define __POSIX_VISIBLE 199209 #define __ISO_C_VISIBLE 1990 #elif _POSIX_C_SOURCE >= 199009 #define __POSIX_VISIBLE 199009 #define __ISO_C_VISIBLE 1990 #else #define __POSIX_VISIBLE 198808 #define __ISO_C_VISIBLE 0 #endif /* _POSIX_C_SOURCE */ /* * Both glibc and OpenBSD enable c11 features when _ISOC11_SOURCE is defined, or * when compiling with -stdc=c11. A strict reading of the standard would suggest * doing it only for the former. However, a strict reading also requires C99 * mode only, so building with C11 is already undefined. Follow glibc's and * OpenBSD's lead for this non-standard configuration for maximum compatibility. */ #if _ISOC11_SOURCE || (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L) #undef __ISO_C_VISIBLE #define __ISO_C_VISIBLE 2011 #endif #else /*- * Deal with _ANSI_SOURCE: * If it is defined, and no other compilation environment is explicitly * requested, then define our internal feature-test macros to zero. This * makes no difference to the preprocessor (undefined symbols in preprocessing * expressions are defined to have value zero), but makes it more convenient for * a test program to print out the values. * * If a program mistakenly defines _ANSI_SOURCE and some other macro such as * _POSIX_C_SOURCE, we will assume that it wants the broader compilation * environment (and in fact we will never get here). */ #if defined(_ANSI_SOURCE) /* Hide almost everything. */ #define __POSIX_VISIBLE 0 #define __XSI_VISIBLE 0 #define __BSD_VISIBLE 0 #define __ISO_C_VISIBLE 1990 #define __EXT1_VISIBLE 0 #elif defined(_C99_SOURCE) /* Localism to specify strict C99 env. */ #define __POSIX_VISIBLE 0 #define __XSI_VISIBLE 0 #define __BSD_VISIBLE 0 #define __ISO_C_VISIBLE 1999 #define __EXT1_VISIBLE 0 #elif defined(_C11_SOURCE) /* Localism to specify strict C11 env. */ #define __POSIX_VISIBLE 0 #define __XSI_VISIBLE 0 #define __BSD_VISIBLE 0 #define __ISO_C_VISIBLE 2011 #define __EXT1_VISIBLE 0 #else /* Default environment: show everything. */ #define __POSIX_VISIBLE 200809 #define __XSI_VISIBLE 700 #define __BSD_VISIBLE 1 #define __ISO_C_VISIBLE 2011 #define __EXT1_VISIBLE 1 #endif #endif /* User override __EXT1_VISIBLE */ #if defined(__STDC_WANT_LIB_EXT1__) #undef __EXT1_VISIBLE #if __STDC_WANT_LIB_EXT1__ #define __EXT1_VISIBLE 1 #else #define __EXT1_VISIBLE 0 #endif #endif /* __STDC_WANT_LIB_EXT1__ */ /* * Nullability qualifiers: currently only supported by Clang. */ #if !(defined(__clang__) && __has_feature(nullability)) #define _Nonnull #define _Nullable #define _Null_unspecified #define __NULLABILITY_PRAGMA_PUSH #define __NULLABILITY_PRAGMA_POP #else #define __NULLABILITY_PRAGMA_PUSH _Pragma("clang diagnostic push") \ _Pragma("clang diagnostic ignored \"-Wnullability-completeness\"") #define __NULLABILITY_PRAGMA_POP _Pragma("clang diagnostic pop") #endif /* * Type Safety Checking * * Clang provides additional attributes to enable checking type safety * properties that cannot be enforced by the C type system. */ #if __has_attribute(__argument_with_type_tag__) && \ __has_attribute(__type_tag_for_datatype__) #define __arg_type_tag(arg_kind, arg_idx, type_tag_idx) \ __attribute__((__argument_with_type_tag__(arg_kind, arg_idx, type_tag_idx))) #define __datatype_type_tag(kind, type) \ __attribute__((__type_tag_for_datatype__(kind, type))) #else #define __arg_type_tag(arg_kind, arg_idx, type_tag_idx) #define __datatype_type_tag(kind, type) #endif /* * Lock annotations. * * Clang provides support for doing basic thread-safety tests at * compile-time, by marking which locks will/should be held when * entering/leaving a functions. * * Furthermore, it is also possible to annotate variables and structure * members to enforce that they are only accessed when certain locks are * held. */ #if __has_extension(c_thread_safety_attributes) #define __lock_annotate(x) __attribute__((x)) #else #define __lock_annotate(x) #endif /* Structure implements a lock. */ #define __lockable __lock_annotate(lockable) /* Function acquires an exclusive or shared lock. */ #define __locks_exclusive(...) \ __lock_annotate(exclusive_lock_function(__VA_ARGS__)) #define __locks_shared(...) \ __lock_annotate(shared_lock_function(__VA_ARGS__)) /* Function attempts to acquire an exclusive or shared lock. */ #define __trylocks_exclusive(...) \ __lock_annotate(exclusive_trylock_function(__VA_ARGS__)) #define __trylocks_shared(...) \ __lock_annotate(shared_trylock_function(__VA_ARGS__)) /* Function releases a lock. */ #define __unlocks(...) __lock_annotate(unlock_function(__VA_ARGS__)) /* Function asserts that an exclusive or shared lock is held. */ #define __asserts_exclusive(...) \ __lock_annotate(assert_exclusive_lock(__VA_ARGS__)) #define __asserts_shared(...) \ __lock_annotate(assert_shared_lock(__VA_ARGS__)) /* Function requires that an exclusive or shared lock is or is not held. */ #define __requires_exclusive(...) \ __lock_annotate(exclusive_locks_required(__VA_ARGS__)) #define __requires_shared(...) \ __lock_annotate(shared_locks_required(__VA_ARGS__)) #define __requires_unlocked(...) \ __lock_annotate(locks_excluded(__VA_ARGS__)) /* Function should not be analyzed. */ #define __no_lock_analysis __lock_annotate(no_thread_safety_analysis) /* * Function or variable should not be sanitized, e.g., by AddressSanitizer. * GCC has the nosanitize attribute, but as a function attribute only, and * warns on use as a variable attribute. */ #if __has_attribute(no_sanitize) && defined(__clang__) #ifdef _KERNEL #define __nosanitizeaddress __attribute__((no_sanitize("kernel-address"))) #define __nosanitizememory __attribute__((no_sanitize("kernel-memory"))) #else #define __nosanitizeaddress __attribute__((no_sanitize("address"))) #define __nosanitizememory __attribute__((no_sanitize("memory"))) #endif #define __nosanitizethread __attribute__((no_sanitize("thread"))) #else #define __nosanitizeaddress #define __nosanitizememory #define __nosanitizethread #endif /* * Make it possible to opt out of stack smashing protection. */ #if __has_attribute(no_stack_protector) #define __nostackprotector __attribute__((no_stack_protector)) #else #define __nostackprotector \ __attribute__((__optimize__("-fno-stack-protector"))) #endif /* Guard variables and structure members by lock. */ #define __guarded_by(x) __lock_annotate(guarded_by(x)) #define __pt_guarded_by(x) __lock_annotate(pt_guarded_by(x)) /* Alignment builtins for better type checking and improved code generation. */ /* Provide fallback versions for other compilers (GCC/Clang < 10): */ #if !__has_builtin(__builtin_is_aligned) #define __builtin_is_aligned(x, align) \ (((__uintptr_t)(x) & ((align) - 1)) == 0) #endif #if !__has_builtin(__builtin_align_up) #define __builtin_align_up(x, align) \ ((__typeof__(x))(((__uintptr_t)(x)+((align)-1))&(~((align)-1)))) #endif #if !__has_builtin(__builtin_align_down) #define __builtin_align_down(x, align) \ ((__typeof__(x))((x)&(~((align)-1)))) #endif #define __align_up(x, y) __builtin_align_up(x, y) #define __align_down(x, y) __builtin_align_down(x, y) #define __is_aligned(x, y) __builtin_is_aligned(x, y) #endif /* !_SYS_CDEFS_H_ */