diff options
Diffstat (limited to 'build-aux')
| -rw-r--r-- | build-aux/.gitignore | 3 | ||||
| -rw-r--r-- | build-aux/arg-nonnull.h | 26 | ||||
| -rw-r--r-- | build-aux/c++defs.h | 271 | ||||
| -rw-r--r-- | build-aux/warn-on-use.h | 109 |
4 files changed, 406 insertions, 3 deletions
diff --git a/build-aux/.gitignore b/build-aux/.gitignore index 913fd8b2..e69de29b 100644 --- a/build-aux/.gitignore +++ b/build-aux/.gitignore @@ -1,3 +0,0 @@ -/arg-nonnull.h -/c++defs.h -/warn-on-use.h diff --git a/build-aux/arg-nonnull.h b/build-aux/arg-nonnull.h new file mode 100644 index 00000000..7e3e2db8 --- /dev/null +++ b/build-aux/arg-nonnull.h @@ -0,0 +1,26 @@ +/* A C macro for declaring that specific arguments must not be NULL. + Copyright (C) 2009, 2010 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify it + under the terms of the GNU General Public License as published + by the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. */ + +/* _GL_ARG_NONNULL((n,...,m)) tells the compiler and static analyzer tools + that the values passed as arguments n, ..., m must be non-NULL pointers. + n = 1 stands for the first argument, n = 2 for the second argument etc. */ +#ifndef _GL_ARG_NONNULL +# if (__GNUC__ == 3 && __GNUC_MINOR__ >= 3) || __GNUC__ > 3 +# define _GL_ARG_NONNULL(params) __attribute__ ((__nonnull__ params)) +# else +# define _GL_ARG_NONNULL(params) +# endif +#endif diff --git a/build-aux/c++defs.h b/build-aux/c++defs.h new file mode 100644 index 00000000..0c2fad7a --- /dev/null +++ b/build-aux/c++defs.h @@ -0,0 +1,271 @@ +/* C++ compatible function declaration macros. + Copyright (C) 2010 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify it + under the terms of the GNU General Public License as published + by the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. */ + +#ifndef _GL_CXXDEFS_H +#define _GL_CXXDEFS_H + +/* The three most frequent use cases of these macros are: + + * For providing a substitute for a function that is missing on some + platforms, but is declared and works fine on the platforms on which + it exists: + + #if @GNULIB_FOO@ + # if !@HAVE_FOO@ + _GL_FUNCDECL_SYS (foo, ...); + # endif + _GL_CXXALIAS_SYS (foo, ...); + _GL_CXXALIASWARN (foo); + #elif defined GNULIB_POSIXCHECK + ... + #endif + + * For providing a replacement for a function that exists on all platforms, + but is broken/insufficient and needs to be replaced on some platforms: + + #if @GNULIB_FOO@ + # if @REPLACE_FOO@ + # if !(defined __cplusplus && defined GNULIB_NAMESPACE) + # undef foo + # define foo rpl_foo + # endif + _GL_FUNCDECL_RPL (foo, ...); + _GL_CXXALIAS_RPL (foo, ...); + # else + _GL_CXXALIAS_SYS (foo, ...); + # endif + _GL_CXXALIASWARN (foo); + #elif defined GNULIB_POSIXCHECK + ... + #endif + + * For providing a replacement for a function that exists on some platforms + but is broken/insufficient and needs to be replaced on some of them and + is additionally either missing or undeclared on some other platforms: + + #if @GNULIB_FOO@ + # if @REPLACE_FOO@ + # if !(defined __cplusplus && defined GNULIB_NAMESPACE) + # undef foo + # define foo rpl_foo + # endif + _GL_FUNCDECL_RPL (foo, ...); + _GL_CXXALIAS_RPL (foo, ...); + # else + # if !@HAVE_FOO@ or if !@HAVE_DECL_FOO@ + _GL_FUNCDECL_SYS (foo, ...); + # endif + _GL_CXXALIAS_SYS (foo, ...); + # endif + _GL_CXXALIASWARN (foo); + #elif defined GNULIB_POSIXCHECK + ... + #endif +*/ + +/* _GL_EXTERN_C declaration; + performs the declaration with C linkage. */ +#if defined __cplusplus +# define _GL_EXTERN_C extern "C" +#else +# define _GL_EXTERN_C extern +#endif + +/* _GL_FUNCDECL_RPL (func, rettype, parameters_and_attributes); + declares a replacement function, named rpl_func, with the given prototype, + consisting of return type, parameters, and attributes. + Example: + _GL_FUNCDECL_RPL (open, int, (const char *filename, int flags, ...) + _GL_ARG_NONNULL ((1))); + */ +#define _GL_FUNCDECL_RPL(func,rettype,parameters_and_attributes) \ + _GL_FUNCDECL_RPL_1 (rpl_##func, rettype, parameters_and_attributes) +#define _GL_FUNCDECL_RPL_1(rpl_func,rettype,parameters_and_attributes) \ + _GL_EXTERN_C rettype rpl_func parameters_and_attributes + +/* _GL_FUNCDECL_SYS (func, rettype, parameters_and_attributes); + declares the system function, named func, with the given prototype, + consisting of return type, parameters, and attributes. + Example: + _GL_FUNCDECL_SYS (open, int, (const char *filename, int flags, ...) + _GL_ARG_NONNULL ((1))); + */ +#define _GL_FUNCDECL_SYS(func,rettype,parameters_and_attributes) \ + _GL_EXTERN_C rettype func parameters_and_attributes + +/* _GL_CXXALIAS_RPL (func, rettype, parameters); + declares a C++ alias called GNULIB_NAMESPACE::func + that redirects to rpl_func, if GNULIB_NAMESPACE is defined. + Example: + _GL_CXXALIAS_RPL (open, int, (const char *filename, int flags, ...)); + */ +#define _GL_CXXALIAS_RPL(func,rettype,parameters) \ + _GL_CXXALIAS_RPL_1 (func, rpl_##func, rettype, parameters) +#if defined __cplusplus && defined GNULIB_NAMESPACE +# define _GL_CXXALIAS_RPL_1(func,rpl_func,rettype,parameters) \ + namespace GNULIB_NAMESPACE \ + { \ + rettype (*const func) parameters = ::rpl_func; \ + } \ + _GL_EXTERN_C int _gl_cxxalias_dummy +#else +# define _GL_CXXALIAS_RPL_1(func,rpl_func,rettype,parameters) \ + _GL_EXTERN_C int _gl_cxxalias_dummy +#endif + +/* _GL_CXXALIAS_RPL_CAST_1 (func, rpl_func, rettype, parameters); + is like _GL_CXXALIAS_RPL_1 (func, rpl_func, rettype, parameters); + except that the C function rpl_func may have a slightly different + declaration. A cast is used to silence the "invalid conversion" error + that would otherwise occur. */ +#if defined __cplusplus && defined GNULIB_NAMESPACE +# define _GL_CXXALIAS_RPL_CAST_1(func,rpl_func,rettype,parameters) \ + namespace GNULIB_NAMESPACE \ + { \ + rettype (*const func) parameters = \ + reinterpret_cast<rettype(*)parameters>(::rpl_func); \ + } \ + _GL_EXTERN_C int _gl_cxxalias_dummy +#else +# define _GL_CXXALIAS_RPL_CAST_1(func,rpl_func,rettype,parameters) \ + _GL_EXTERN_C int _gl_cxxalias_dummy +#endif + +/* _GL_CXXALIAS_SYS (func, rettype, parameters); + declares a C++ alias called GNULIB_NAMESPACE::func + that redirects to the system provided function func, if GNULIB_NAMESPACE + is defined. + Example: + _GL_CXXALIAS_SYS (open, int, (const char *filename, int flags, ...)); + */ +#if defined __cplusplus && defined GNULIB_NAMESPACE + /* If we were to write + rettype (*const func) parameters = ::func; + like above in _GL_CXXALIAS_RPL_1, the compiler could optimize calls + better (remove an indirection through a 'static' pointer variable), + but then the _GL_CXXALIASWARN macro below would cause a warning not only + for uses of ::func but also for uses of GNULIB_NAMESPACE::func. */ +# define _GL_CXXALIAS_SYS(func,rettype,parameters) \ + namespace GNULIB_NAMESPACE \ + { \ + static rettype (*func) parameters = ::func; \ + } \ + _GL_EXTERN_C int _gl_cxxalias_dummy +#else +# define _GL_CXXALIAS_SYS(func,rettype,parameters) \ + _GL_EXTERN_C int _gl_cxxalias_dummy +#endif + +/* _GL_CXXALIAS_SYS_CAST (func, rettype, parameters); + is like _GL_CXXALIAS_SYS (func, rettype, parameters); + except that the C function func may have a slightly different declaration. + A cast is used to silence the "invalid conversion" error that would + otherwise occur. */ +#if defined __cplusplus && defined GNULIB_NAMESPACE +# define _GL_CXXALIAS_SYS_CAST(func,rettype,parameters) \ + namespace GNULIB_NAMESPACE \ + { \ + static rettype (*func) parameters = \ + reinterpret_cast<rettype(*)parameters>(::func); \ + } \ + _GL_EXTERN_C int _gl_cxxalias_dummy +#else +# define _GL_CXXALIAS_SYS_CAST(func,rettype,parameters) \ + _GL_EXTERN_C int _gl_cxxalias_dummy +#endif + +/* _GL_CXXALIAS_SYS_CAST2 (func, rettype, parameters, rettype2, parameters2); + is like _GL_CXXALIAS_SYS (func, rettype, parameters); + except that the C function is picked among a set of overloaded functions, + namely the one with rettype2 and parameters2. Two consecutive casts + are used to silence the "cannot find a match" and "invalid conversion" + errors that would otherwise occur. */ +#if defined __cplusplus && defined GNULIB_NAMESPACE + /* The outer cast must be a reinterpret_cast. + The inner cast: When the function is defined as a set of overloaded + functions, it works as a static_cast<>, choosing the designated variant. + When the function is defined as a single variant, it works as a + reinterpret_cast<>. The parenthesized cast syntax works both ways. */ +# define _GL_CXXALIAS_SYS_CAST2(func,rettype,parameters,rettype2,parameters2) \ + namespace GNULIB_NAMESPACE \ + { \ + static rettype (*func) parameters = \ + reinterpret_cast<rettype(*)parameters>( \ + (rettype2(*)parameters2)(::func)); \ + } \ + _GL_EXTERN_C int _gl_cxxalias_dummy +#else +# define _GL_CXXALIAS_SYS_CAST2(func,rettype,parameters,rettype2,parameters2) \ + _GL_EXTERN_C int _gl_cxxalias_dummy +#endif + +/* _GL_CXXALIASWARN (func); + causes a warning to be emitted when ::func is used but not when + GNULIB_NAMESPACE::func is used. func must be defined without overloaded + variants. */ +#if defined __cplusplus && defined GNULIB_NAMESPACE +# define _GL_CXXALIASWARN(func) \ + _GL_CXXALIASWARN_1 (func, GNULIB_NAMESPACE) +# define _GL_CXXALIASWARN_1(func,namespace) \ + _GL_CXXALIASWARN_2 (func, namespace) +/* To work around GCC bug <http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43881>, + we enable the warning only when not optimizing. */ +# if !__OPTIMIZE__ +# define _GL_CXXALIASWARN_2(func,namespace) \ + _GL_WARN_ON_USE (func, \ + "The symbol ::" #func " refers to the system function. " \ + "Use " #namespace "::" #func " instead.") +# elif __GNUC__ >= 3 && GNULIB_STRICT_CHECKING +# define _GL_CXXALIASWARN_2(func,namespace) \ + extern __typeof__ (func) func +# else +# define _GL_CXXALIASWARN_2(func,namespace) \ + _GL_EXTERN_C int _gl_cxxalias_dummy +# endif +#else +# define _GL_CXXALIASWARN(func) \ + _GL_EXTERN_C int _gl_cxxalias_dummy +#endif + +/* _GL_CXXALIASWARN1 (func, rettype, parameters_and_attributes); + causes a warning to be emitted when the given overloaded variant of ::func + is used but not when GNULIB_NAMESPACE::func is used. */ +#if defined __cplusplus && defined GNULIB_NAMESPACE +# define _GL_CXXALIASWARN1(func,rettype,parameters_and_attributes) \ + _GL_CXXALIASWARN1_1 (func, rettype, parameters_and_attributes, \ + GNULIB_NAMESPACE) +# define _GL_CXXALIASWARN1_1(func,rettype,parameters_and_attributes,namespace) \ + _GL_CXXALIASWARN1_2 (func, rettype, parameters_and_attributes, namespace) +/* To work around GCC bug <http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43881>, + we enable the warning only when not optimizing. */ +# if !__OPTIMIZE__ +# define _GL_CXXALIASWARN1_2(func,rettype,parameters_and_attributes,namespace) \ + _GL_WARN_ON_USE_CXX (func, rettype, parameters_and_attributes, \ + "The symbol ::" #func " refers to the system function. " \ + "Use " #namespace "::" #func " instead.") +# elif __GNUC__ >= 3 && GNULIB_STRICT_CHECKING +# define _GL_CXXALIASWARN1_2(func,rettype,parameters_and_attributes,namespace) \ + extern __typeof__ (func) func +# else +# define _GL_CXXALIASWARN1_2(func,rettype,parameters_and_attributes,namespace) \ + _GL_EXTERN_C int _gl_cxxalias_dummy +# endif +#else +# define _GL_CXXALIASWARN1(func,rettype,parameters_and_attributes) \ + _GL_EXTERN_C int _gl_cxxalias_dummy +#endif + +#endif /* _GL_CXXDEFS_H */ diff --git a/build-aux/warn-on-use.h b/build-aux/warn-on-use.h new file mode 100644 index 00000000..171e5991 --- /dev/null +++ b/build-aux/warn-on-use.h @@ -0,0 +1,109 @@ +/* A C macro for emitting warnings if a function is used. + Copyright (C) 2010 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify it + under the terms of the GNU General Public License as published + by the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. */ + +/* _GL_WARN_ON_USE (function, "literal string") issues a declaration + for FUNCTION which will then trigger a compiler warning containing + the text of "literal string" anywhere that function is called, if + supported by the compiler. If the compiler does not support this + feature, the macro expands to an unused extern declaration. + + This macro is useful for marking a function as a potential + portability trap, with the intent that "literal string" include + instructions on the replacement function that should be used + instead. However, one of the reasons that a function is a + portability trap is if it has the wrong signature. Declaring + FUNCTION with a different signature in C is a compilation error, so + this macro must use the same type as any existing declaration so + that programs that avoid the problematic FUNCTION do not fail to + compile merely because they included a header that poisoned the + function. But this implies that _GL_WARN_ON_USE is only safe to + use if FUNCTION is known to already have a declaration. Use of + this macro implies that there must not be any other macro hiding + the declaration of FUNCTION; but undefining FUNCTION first is part + of the poisoning process anyway (although for symbols that are + provided only via a macro, the result is a compilation error rather + than a warning containing "literal string"). Also note that in + C++, it is only safe to use if FUNCTION has no overloads. + + For an example, it is possible to poison 'getline' by: + - adding a call to gl_WARN_ON_USE_PREPARE([[#include <stdio.h>]], + [getline]) in configure.ac, which potentially defines + HAVE_RAW_DECL_GETLINE + - adding this code to a header that wraps the system <stdio.h>: + #undef getline + #if HAVE_RAW_DECL_GETLINE + _GL_WARN_ON_USE (getline, "getline is required by POSIX 2008, but" + "not universally present; use the gnulib module getline"); + #endif + + It is not possible to directly poison global variables. But it is + possible to write a wrapper accessor function, and poison that + (less common usage, like &environ, will cause a compilation error + rather than issue the nice warning, but the end result of informing + the developer about their portability problem is still achieved): + #if HAVE_RAW_DECL_ENVIRON + static inline char ***rpl_environ (void) { return &environ; } + _GL_WARN_ON_USE (rpl_environ, "environ is not always properly declared"); + # undef environ + # define environ (*rpl_environ ()) + #endif + */ +#ifndef _GL_WARN_ON_USE + +# if 4 < __GNUC__ || (__GNUC__ == 4 && 3 <= __GNUC_MINOR__) +/* A compiler attribute is available in gcc versions 4.3.0 and later. */ +# define _GL_WARN_ON_USE(function, message) \ +extern __typeof__ (function) function __attribute__ ((__warning__ (message))) +# elif __GNUC__ >= 3 && GNULIB_STRICT_CHECKING +/* Verify the existence of the function. */ +# define _GL_WARN_ON_USE(function, message) \ +extern __typeof__ (function) function +# else /* Unsupported. */ +# define _GL_WARN_ON_USE(function, message) \ +_GL_WARN_EXTERN_C int _gl_warn_on_use +# endif +#endif + +/* _GL_WARN_ON_USE_CXX (function, rettype, parameters_and_attributes, "string") + is like _GL_WARN_ON_USE (function, "string"), except that the function is + declared with the given prototype, consisting of return type, parameters, + and attributes. + This variant is useful for overloaded functions in C++. _GL_WARN_ON_USE does + not work in this case. */ +#ifndef _GL_WARN_ON_USE_CXX +# if 4 < __GNUC__ || (__GNUC__ == 4 && 3 <= __GNUC_MINOR__) +# define _GL_WARN_ON_USE_CXX(function,rettype,parameters_and_attributes,msg) \ +extern rettype function parameters_and_attributes \ + __attribute__ ((__warning__ (msg))) +# elif __GNUC__ >= 3 && GNULIB_STRICT_CHECKING +/* Verify the existence of the function. */ +# define _GL_WARN_ON_USE_CXX(function,rettype,parameters_and_attributes,msg) \ +extern rettype function parameters_and_attributes +# else /* Unsupported. */ +# define _GL_WARN_ON_USE_CXX(function,rettype,parameters_and_attributes,msg) \ +_GL_WARN_EXTERN_C int _gl_warn_on_use +# endif +#endif + +/* _GL_WARN_EXTERN_C declaration; + performs the declaration with C linkage. */ +#ifndef _GL_WARN_EXTERN_C +# if defined __cplusplus +# define _GL_WARN_EXTERN_C extern "C" +# else +# define _GL_WARN_EXTERN_C extern +# endif +#endif |