diff options
Diffstat (limited to 'lib/ccan/cast')
| -rw-r--r-- | lib/ccan/cast/LICENSE | 165 | ||||
| -rw-r--r-- | lib/ccan/cast/_info | 84 | ||||
| -rw-r--r-- | lib/ccan/cast/cast.h | 129 | ||||
| -rw-r--r-- | lib/ccan/cast/test/compile_fail-cast_const.c | 29 | ||||
| -rw-r--r-- | lib/ccan/cast/test/compile_fail-cast_const2.c | 29 | ||||
| -rw-r--r-- | lib/ccan/cast/test/compile_fail-cast_const3.c | 29 | ||||
| -rw-r--r-- | lib/ccan/cast/test/compile_fail-cast_signed-const.c | 22 | ||||
| -rw-r--r-- | lib/ccan/cast/test/compile_fail-cast_signed-sizesame.c | 29 | ||||
| -rw-r--r-- | lib/ccan/cast/test/compile_fail-cast_signed.c | 17 | ||||
| -rw-r--r-- | lib/ccan/cast/test/compile_fail-cast_static-2.c | 23 | ||||
| -rw-r--r-- | lib/ccan/cast/test/compile_fail-cast_static-3.c | 21 | ||||
| -rw-r--r-- | lib/ccan/cast/test/compile_fail-cast_static.c | 17 | ||||
| -rw-r--r-- | lib/ccan/cast/test/compile_ok-cast_void.c | 12 |
13 files changed, 606 insertions, 0 deletions
diff --git a/lib/ccan/cast/LICENSE b/lib/ccan/cast/LICENSE new file mode 100644 index 0000000000..cca7fc278f --- /dev/null +++ b/lib/ccan/cast/LICENSE @@ -0,0 +1,165 @@ + GNU LESSER GENERAL PUBLIC LICENSE + Version 3, 29 June 2007 + + Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/> + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + + + This version of the GNU Lesser General Public License incorporates +the terms and conditions of version 3 of the GNU General Public +License, supplemented by the additional permissions listed below. + + 0. Additional Definitions. + + As used herein, "this License" refers to version 3 of the GNU Lesser +General Public License, and the "GNU GPL" refers to version 3 of the GNU +General Public License. + + "The Library" refers to a covered work governed by this License, +other than an Application or a Combined Work as defined below. + + An "Application" is any work that makes use of an interface provided +by the Library, but which is not otherwise based on the Library. +Defining a subclass of a class defined by the Library is deemed a mode +of using an interface provided by the Library. + + A "Combined Work" is a work produced by combining or linking an +Application with the Library. The particular version of the Library +with which the Combined Work was made is also called the "Linked +Version". + + The "Minimal Corresponding Source" for a Combined Work means the +Corresponding Source for the Combined Work, excluding any source code +for portions of the Combined Work that, considered in isolation, are +based on the Application, and not on the Linked Version. + + The "Corresponding Application Code" for a Combined Work means the +object code and/or source code for the Application, including any data +and utility programs needed for reproducing the Combined Work from the +Application, but excluding the System Libraries of the Combined Work. + + 1. Exception to Section 3 of the GNU GPL. + + You may convey a covered work under sections 3 and 4 of this License +without being bound by section 3 of the GNU GPL. + + 2. Conveying Modified Versions. + + If you modify a copy of the Library, and, in your modifications, a +facility refers to a function or data to be supplied by an Application +that uses the facility (other than as an argument passed when the +facility is invoked), then you may convey a copy of the modified +version: + + a) under this License, provided that you make a good faith effort to + ensure that, in the event an Application does not supply the + function or data, the facility still operates, and performs + whatever part of its purpose remains meaningful, or + + b) under the GNU GPL, with none of the additional permissions of + this License applicable to that copy. + + 3. Object Code Incorporating Material from Library Header Files. + + The object code form of an Application may incorporate material from +a header file that is part of the Library. You may convey such object +code under terms of your choice, provided that, if the incorporated +material is not limited to numerical parameters, data structure +layouts and accessors, or small macros, inline functions and templates +(ten or fewer lines in length), you do both of the following: + + a) Give prominent notice with each copy of the object code that the + Library is used in it and that the Library and its use are + covered by this License. + + b) Accompany the object code with a copy of the GNU GPL and this license + document. + + 4. Combined Works. + + You may convey a Combined Work under terms of your choice that, +taken together, effectively do not restrict modification of the +portions of the Library contained in the Combined Work and reverse +engineering for debugging such modifications, if you also do each of +the following: + + a) Give prominent notice with each copy of the Combined Work that + the Library is used in it and that the Library and its use are + covered by this License. + + b) Accompany the Combined Work with a copy of the GNU GPL and this license + document. + + c) For a Combined Work that displays copyright notices during + execution, include the copyright notice for the Library among + these notices, as well as a reference directing the user to the + copies of the GNU GPL and this license document. + + d) Do one of the following: + + 0) Convey the Minimal Corresponding Source under the terms of this + License, and the Corresponding Application Code in a form + suitable for, and under terms that permit, the user to + recombine or relink the Application with a modified version of + the Linked Version to produce a modified Combined Work, in the + manner specified by section 6 of the GNU GPL for conveying + Corresponding Source. + + 1) Use a suitable shared library mechanism for linking with the + Library. A suitable mechanism is one that (a) uses at run time + a copy of the Library already present on the user's computer + system, and (b) will operate properly with a modified version + of the Library that is interface-compatible with the Linked + Version. + + e) Provide Installation Information, but only if you would otherwise + be required to provide such information under section 6 of the + GNU GPL, and only to the extent that such information is + necessary to install and execute a modified version of the + Combined Work produced by recombining or relinking the + Application with a modified version of the Linked Version. (If + you use option 4d0, the Installation Information must accompany + the Minimal Corresponding Source and Corresponding Application + Code. If you use option 4d1, you must provide the Installation + Information in the manner specified by section 6 of the GNU GPL + for conveying Corresponding Source.) + + 5. Combined Libraries. + + You may place library facilities that are a work based on the +Library side by side in a single library together with other library +facilities that are not Applications and are not covered by this +License, and convey such a combined library under terms of your +choice, if you do both of the following: + + a) Accompany the combined library with a copy of the same work based + on the Library, uncombined with any other library facilities, + conveyed under the terms of this License. + + b) Give prominent notice with the combined library that part of it + is a work based on the Library, and explaining where to find the + accompanying uncombined form of the same work. + + 6. Revised Versions of the GNU Lesser General Public License. + + The Free Software Foundation may publish revised and/or new versions +of the GNU Lesser General Public License from time to time. Such new +versions will be similar in spirit to the present version, but may +differ in detail to address new problems or concerns. + + Each version is given a distinguishing version number. If the +Library as you received it specifies that a certain numbered version +of the GNU Lesser General Public License "or any later version" +applies to it, you have the option of following the terms and +conditions either of that published version or of any later version +published by the Free Software Foundation. If the Library as you +received it does not specify a version number of the GNU Lesser +General Public License, you may choose any version of the GNU Lesser +General Public License ever published by the Free Software Foundation. + + If the Library as you received it specifies that a proxy can decide +whether future versions of the GNU Lesser General Public License shall +apply, that proxy's public statement of acceptance of any version is +permanent authorization for you to choose that version for the +Library. diff --git a/lib/ccan/cast/_info b/lib/ccan/cast/_info new file mode 100644 index 0000000000..5f82a05b8f --- /dev/null +++ b/lib/ccan/cast/_info @@ -0,0 +1,84 @@ +#include <string.h> +#include "config.h" + +/** + * cast - routines for safer casting. + * + * Often you want to cast in a limited way, such as removing a const or + * switching between integer types. However, normal casts will work on + * almost any type, making them dangerous when the code changes. + * + * These C++-inspired macros serve two purposes: they make it clear the + * exact reason for the cast, and they also (with some compilers) cause + * errors when misused. + * + * Based on Jan Engelhardt's libHX macros: http://libhx.sourceforge.net/ + * + * Author: Jan Engelhardt + * Maintainer: Rusty Russell <rusty@rustcorp.com.au> + * License: LGPL + * + * Example: + * // Given "test" contains "3 t's in 'test string' + * #include <ccan/cast/cast.h> + * #include <stdint.h> + * #include <stdio.h> + * + * // Find char @orig in @str, if @repl, replace them. Return number. + * static size_t find_chars(char *str, char orig, char repl) + * { + * size_t i, count = 0; + * for (i = 0; str[i]; i++) { + * if (str[i] == orig) { + * count++; + * if (repl) + * str[i] = repl; + * } + * } + * return count; + * } + * + * // Terrible hash function. + * static uint64_t hash_string(const unsigned char *str) + * { + * size_t i; + * uint64_t hash = 0; + * for (i = 0; str[i]; i++) + * hash += str[i]; + * return hash; + * } + * + * int main(int argc, char *argv[]) + * { + * uint64_t hash; + * + * // find_chars wants a non-const string, but doesn't + * // need it if repl == 0. + * printf("%zu %c's in 'test string'\n", + * find_chars(cast_const(char *, "test string"), + * argv[1][0], 0), + * argv[1][0]); + * + * // hash_string wants an unsigned char. + * hash = hash_string(cast_signed(unsigned char *, argv[1])); + * + * // Need a long long to hand to printf. + * printf("Hash of '%s' = %llu\n", argv[1], + * cast_static(unsigned long long, hash)); + * return 0; + * } + * + */ +int main(int argc, char *argv[]) +{ + /* Expect exactly one argument */ + if (argc != 2) + return 1; + + if (strcmp(argv[1], "depends") == 0) { + printf("ccan/build_assert\n"); + return 0; + } + + return 1; +} diff --git a/lib/ccan/cast/cast.h b/lib/ccan/cast/cast.h new file mode 100644 index 0000000000..daebd85723 --- /dev/null +++ b/lib/ccan/cast/cast.h @@ -0,0 +1,129 @@ +#ifndef CCAN_CAST_H +#define CCAN_CAST_H +#include "config.h" +#include <stdint.h> +#include <ccan/build_assert/build_assert.h> + +/** + * cast_signed - cast a (const) char * to/from (const) signed/unsigned char *. + * @type: some char * variant. + * @expr: expression (of some char * variant) to cast. + * + * Some libraries insist on an unsigned char in various places; cast_signed + * makes sure (with suitable compiler) that the expression you are casting + * only differs in signed/unsigned, not in type or const-ness. + */ +#define cast_signed(type, expr) \ + ((type)(expr) \ + + BUILD_ASSERT_OR_ZERO(cast_sign_compatible(type, (expr)))) + +/** + * cast_const - remove a const qualifier from a pointer. + * @type: some pointer type. + * @expr: expression to cast. + * + * This ensures that you are only removing the const qualifier from an + * expression. The expression must otherwise match @type. + * + * If @type is a pointer to a pointer, you must use cast_const2 (etc). + * + * Example: + * // Dumb open-coded strstr variant. + * static char *find_needle(const char *haystack) + * { + * size_t i; + * for (i = 0; i < strlen(haystack); i++) + * if (memcmp("needle", haystack+i, strlen("needle")) == 0) + * return cast_const(char *, haystack+i); + * return NULL; + * } + */ +#define cast_const(type, expr) \ + ((type)((intptr_t)(expr) \ + + BUILD_ASSERT_OR_ZERO(cast_const_compat1((expr), type)))) + +/** + * cast_const2 - remove a const qualifier from a pointer to a pointer. + * @type: some pointer to pointer type. + * @expr: expression to cast. + * + * This ensures that you are only removing the const qualifier from an + * expression. The expression must otherwise match @type. + */ +#define cast_const2(type, expr) \ + ((type)((intptr_t)(expr) \ + + BUILD_ASSERT_OR_ZERO(cast_const_compat2((expr), type)))) + +/** + * cast_const3 - remove a const from a pointer to a pointer to a pointer.. + * @type: some pointer to pointer to pointer type. + * @expr: expression to cast. + * + * This ensures that you are only removing the const qualifier from an + * expression. The expression must otherwise match @type. + */ +#define cast_const3(type, expr) \ + ((type)((intptr_t)(expr) \ + + BUILD_ASSERT_OR_ZERO(cast_const_compat3((expr), type)))) + + +/** + * cast_static - explicit mimic of implicit cast. + * @type: some type. + * @expr: expression to cast. + * + * This ensures that the cast is not to or from a pointer: it can only be + * an implicit cast, such as a pointer to a similar const pointer, or between + * integral types. + */ +#if HAVE_COMPOUND_LITERALS +#define cast_static(type, expr) \ + ((struct { type x; }){(expr)}.x) +#else +#define cast_static(type, expr) \ + ((type)(expr)) +#endif + +/* Herein lies the gcc magic to evoke compile errors. */ +#if HAVE_BUILTIN_CHOOSE_EXPR && HAVE_BUILTIN_TYPES_COMPATIBLE_P && HAVE_TYPEOF +#define cast_sign_compatible(t, e) \ + __builtin_choose_expr( \ + __builtin_types_compatible_p(__typeof__(t), char *) || \ + __builtin_types_compatible_p(__typeof__(t), signed char *) || \ + __builtin_types_compatible_p(__typeof__(t), unsigned char *), \ + /* if type is not const qualified */ \ + __builtin_types_compatible_p(__typeof__(e), char *) || \ + __builtin_types_compatible_p(__typeof__(e), signed char *) || \ + __builtin_types_compatible_p(__typeof__(e), unsigned char *), \ + /* and if it is... */ \ + __builtin_types_compatible_p(__typeof__(e), const char *) || \ + __builtin_types_compatible_p(__typeof__(e), const signed char *) || \ + __builtin_types_compatible_p(__typeof__(e), const unsigned char *) ||\ + __builtin_types_compatible_p(__typeof__(e), char *) || \ + __builtin_types_compatible_p(__typeof__(e), signed char *) || \ + __builtin_types_compatible_p(__typeof__(e), unsigned char *) \ + ) + +#define cast_const_strip1(expr) \ + __typeof__(*(struct { int z; __typeof__(expr) x; }){0}.x) +#define cast_const_strip2(expr) \ + __typeof__(**(struct { int z; __typeof__(expr) x; }){0}.x) +#define cast_const_strip3(expr) \ + __typeof__(***(struct { int z; __typeof__(expr) x; }){0}.x) +#define cast_const_compat1(expr, type) \ + __builtin_types_compatible_p(cast_const_strip1(expr), \ + cast_const_strip1(type)) +#define cast_const_compat2(expr, type) \ + __builtin_types_compatible_p(cast_const_strip2(expr), \ + cast_const_strip2(type)) +#define cast_const_compat3(expr, type) \ + __builtin_types_compatible_p(cast_const_strip3(expr), \ + cast_const_strip3(type)) +#else +#define cast_sign_compatible(type, expr) \ + (sizeof(*(type)0) == 1 && sizeof(*(expr)) == 1) +#define cast_const_compat1(expr, type) (1) +#define cast_const_compat2(expr, type) (1) +#define cast_const_compat3(expr, type) (1) +#endif +#endif /* CCAN_CAST_H */ diff --git a/lib/ccan/cast/test/compile_fail-cast_const.c b/lib/ccan/cast/test/compile_fail-cast_const.c new file mode 100644 index 0000000000..277f3de1c4 --- /dev/null +++ b/lib/ccan/cast/test/compile_fail-cast_const.c @@ -0,0 +1,29 @@ +#include <ccan/cast/cast.h> +#include <stdlib.h> + +/* Note: this *isn't* sizeof(char) on all platforms. */ +struct char_struct { + char c; +}; + +int main(int argc, char *argv[]) +{ + char *uc; + const +#ifdef FAIL + struct char_struct +#else + char +#endif + *p = NULL; + + uc = cast_const(char *, p); + (void) uc; /* Suppress unused-but-set-variable warning. */ + return 0; +} + +#ifdef FAIL +#if !HAVE_TYPEOF||!HAVE_BUILTIN_CHOOSE_EXPR||!HAVE_BUILTIN_TYPES_COMPATIBLE_P +#error "Unfortunately we don't fail if cast_const can only use size" +#endif +#endif diff --git a/lib/ccan/cast/test/compile_fail-cast_const2.c b/lib/ccan/cast/test/compile_fail-cast_const2.c new file mode 100644 index 0000000000..e671e88eda --- /dev/null +++ b/lib/ccan/cast/test/compile_fail-cast_const2.c @@ -0,0 +1,29 @@ +#include <ccan/cast/cast.h> +#include <stdlib.h> + +/* Note: this *isn't* sizeof(char) on all platforms. */ +struct char_struct { + char c; +}; + +int main(int argc, char *argv[]) +{ + char **uc; + const +#ifdef FAIL + struct char_struct +#else + char +#endif + **p = NULL; + + uc = cast_const2(char **, p); + (void) uc; /* Suppress unused-but-set-variable warning. */ + return 0; +} + +#ifdef FAIL +#if !HAVE_TYPEOF||!HAVE_BUILTIN_CHOOSE_EXPR||!HAVE_BUILTIN_TYPES_COMPATIBLE_P +#error "Unfortunately we don't fail if cast_const can only use size" +#endif +#endif diff --git a/lib/ccan/cast/test/compile_fail-cast_const3.c b/lib/ccan/cast/test/compile_fail-cast_const3.c new file mode 100644 index 0000000000..e958e2dde5 --- /dev/null +++ b/lib/ccan/cast/test/compile_fail-cast_const3.c @@ -0,0 +1,29 @@ +#include <ccan/cast/cast.h> +#include <stdlib.h> + +/* Note: this *isn't* sizeof(char) on all platforms. */ +struct char_struct { + char c; +}; + +int main(int argc, char *argv[]) +{ + char ***uc; + const +#ifdef FAIL + struct char_struct +#else + char +#endif + ***p = NULL; + + uc = cast_const3(char ***, p); + (void) uc; /* Suppress unused-but-set-variable warning. */ + return 0; +} + +#ifdef FAIL +#if !HAVE_TYPEOF||!HAVE_BUILTIN_CHOOSE_EXPR||!HAVE_BUILTIN_TYPES_COMPATIBLE_P +#error "Unfortunately we don't fail if cast_const can only use size" +#endif +#endif diff --git a/lib/ccan/cast/test/compile_fail-cast_signed-const.c b/lib/ccan/cast/test/compile_fail-cast_signed-const.c new file mode 100644 index 0000000000..9971dc8eb3 --- /dev/null +++ b/lib/ccan/cast/test/compile_fail-cast_signed-const.c @@ -0,0 +1,22 @@ +#include <ccan/cast/cast.h> +#include <stdlib.h> + +int main(int argc, char *argv[]) +{ + unsigned char *uc; +#ifdef FAIL + const +#endif + char + *p = NULL; + + uc = cast_signed(unsigned char *, p); + (void) uc; /* Suppress unused-but-set-variable warning. */ + return 0; +} + +#ifdef FAIL +#if !HAVE_TYPEOF||!HAVE_BUILTIN_CHOOSE_EXPR||!HAVE_BUILTIN_TYPES_COMPATIBLE_P +#error "Unfortunately we don't fail if cast_const can only use size" +#endif +#endif diff --git a/lib/ccan/cast/test/compile_fail-cast_signed-sizesame.c b/lib/ccan/cast/test/compile_fail-cast_signed-sizesame.c new file mode 100644 index 0000000000..2bc40b2f46 --- /dev/null +++ b/lib/ccan/cast/test/compile_fail-cast_signed-sizesame.c @@ -0,0 +1,29 @@ +#include <ccan/cast/cast.h> +#include <stdlib.h> + +/* Note: this *isn't* sizeof(char) on all platforms. */ +struct char_struct { + char c; +}; + +int main(int argc, char *argv[]) +{ + unsigned char *uc; +#ifdef FAIL + struct char_struct +#else + char +#endif + *p = NULL; + + uc = cast_signed(unsigned char *, p); + + (void) uc; /* Suppress unused-but-set-variable warning. */ + return 0; +} + +#ifdef FAIL +#if !HAVE_TYPEOF||!HAVE_BUILTIN_CHOOSE_EXPR||!HAVE_BUILTIN_TYPES_COMPATIBLE_P +#error "Unfortunately we don't fail if cast_signed can only use size" +#endif +#endif diff --git a/lib/ccan/cast/test/compile_fail-cast_signed.c b/lib/ccan/cast/test/compile_fail-cast_signed.c new file mode 100644 index 0000000000..66bcc0a1b5 --- /dev/null +++ b/lib/ccan/cast/test/compile_fail-cast_signed.c @@ -0,0 +1,17 @@ +#include <ccan/cast/cast.h> +#include <stdlib.h> + +int main(int argc, char *argv[]) +{ + unsigned char *uc; +#ifdef FAIL + int +#else + char +#endif + *p = NULL; + + uc = cast_signed(unsigned char *, p); + (void) uc; /* Suppress unused-but-set-variable warning. */ + return 0; +} diff --git a/lib/ccan/cast/test/compile_fail-cast_static-2.c b/lib/ccan/cast/test/compile_fail-cast_static-2.c new file mode 100644 index 0000000000..8a12025384 --- /dev/null +++ b/lib/ccan/cast/test/compile_fail-cast_static-2.c @@ -0,0 +1,23 @@ +#include <ccan/cast/cast.h> +#include <stdlib.h> + +int main(int argc, char *argv[]) +{ + char *c; +#ifdef FAIL + long +#else + char +#endif + *p = 0; + + c = cast_static(char *, p); + (void) c; /* Suppress unused-but-set-variable warning. */ + return 0; +} + +#ifdef FAIL +#if !HAVE_COMPOUND_LITERALS +#error "Unfortunately we don't fail if cast_static is a noop" +#endif +#endif diff --git a/lib/ccan/cast/test/compile_fail-cast_static-3.c b/lib/ccan/cast/test/compile_fail-cast_static-3.c new file mode 100644 index 0000000000..6296b75276 --- /dev/null +++ b/lib/ccan/cast/test/compile_fail-cast_static-3.c @@ -0,0 +1,21 @@ +#include <ccan/cast/cast.h> +#include <stdlib.h> + +int main(int argc, char *argv[]) +{ + char *c; +#ifdef FAIL + const +#endif + char *p = 0; + + c = cast_static(char *, p); + (void) c; /* Suppress unused-but-set-variable warning. */ + return 0; +} + +#ifdef FAIL +#if !HAVE_COMPOUND_LITERALS +#error "Unfortunately we don't fail if cast_static is a noop" +#endif +#endif diff --git a/lib/ccan/cast/test/compile_fail-cast_static.c b/lib/ccan/cast/test/compile_fail-cast_static.c new file mode 100644 index 0000000000..0f9e478047 --- /dev/null +++ b/lib/ccan/cast/test/compile_fail-cast_static.c @@ -0,0 +1,17 @@ +#include <ccan/cast/cast.h> +#include <stdlib.h> + +int main(int argc, char *argv[]) +{ + char c; +#ifdef FAIL + char * +#else + long +#endif + x = 0; + + c = cast_static(char, x); + (void) c; /* Suppress unused-but-set-variable warning. */ + return 0; +} diff --git a/lib/ccan/cast/test/compile_ok-cast_void.c b/lib/ccan/cast/test/compile_ok-cast_void.c new file mode 100644 index 0000000000..c649d283b3 --- /dev/null +++ b/lib/ccan/cast/test/compile_ok-cast_void.c @@ -0,0 +1,12 @@ +#include <ccan/cast/cast.h> + +static void *remove_void(const void *p) +{ + return cast_const(void *, p); +} + +int main(void) +{ + void *p = remove_void("foo"); + return !p; +} |