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Diffstat (limited to 'gl/msvc-inval.h')
| -rw-r--r-- | gl/msvc-inval.h | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/gl/msvc-inval.h b/gl/msvc-inval.h new file mode 100644 index 0000000..42ed4a0 --- /dev/null +++ b/gl/msvc-inval.h @@ -0,0 +1,222 @@ +/* Invalid parameter handler for MSVC runtime libraries. + Copyright (C) 2011-2021 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1, 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 Lesser General Public License along + with this program; if not, see <https://www.gnu.org/licenses/>. */ + +#ifndef _MSVC_INVAL_H +#define _MSVC_INVAL_H + +/* With MSVC runtime libraries with the "invalid parameter handler" concept, + functions like fprintf(), dup2(), or close() crash when the caller passes + an invalid argument. But POSIX wants error codes (such as EINVAL or EBADF) + instead. + This file defines macros that turn such an invalid parameter notification + into a non-local exit. An error code can then be produced at the target + of this exit. You can thus write code like + + TRY_MSVC_INVAL + { + <Code that can trigger an invalid parameter notification + but does not do 'return', 'break', 'continue', nor 'goto'.> + } + CATCH_MSVC_INVAL + { + <Code that handles an invalid parameter notification + but does not do 'return', 'break', 'continue', nor 'goto'.> + } + DONE_MSVC_INVAL; + + This entire block expands to a single statement. + + The handling of invalid parameters can be done in three ways: + + * The default way, which is reasonable for programs (not libraries): + AC_DEFINE([MSVC_INVALID_PARAMETER_HANDLING], [DEFAULT_HANDLING]) + + * The way for libraries that make "hairy" calls (like close(-1), or + fclose(fp) where fileno(fp) is closed, or simply getdtablesize()): + AC_DEFINE([MSVC_INVALID_PARAMETER_HANDLING], [HAIRY_LIBRARY_HANDLING]) + + * The way for libraries that make no "hairy" calls: + AC_DEFINE([MSVC_INVALID_PARAMETER_HANDLING], [SANE_LIBRARY_HANDLING]) + */ + +#define DEFAULT_HANDLING 0 +#define HAIRY_LIBRARY_HANDLING 1 +#define SANE_LIBRARY_HANDLING 2 + +#if HAVE_MSVC_INVALID_PARAMETER_HANDLER \ + && !(MSVC_INVALID_PARAMETER_HANDLING == SANE_LIBRARY_HANDLING) +/* A native Windows platform with the "invalid parameter handler" concept, + and either DEFAULT_HANDLING or HAIRY_LIBRARY_HANDLING. */ + +# if MSVC_INVALID_PARAMETER_HANDLING == DEFAULT_HANDLING +/* Default handling. */ + +# ifdef __cplusplus +extern "C" { +# endif + +/* Ensure that the invalid parameter handler in installed that just returns. + Because we assume no other part of the program installs a different + invalid parameter handler, this solution is multithread-safe. */ +extern void gl_msvc_inval_ensure_handler (void); + +# ifdef __cplusplus +} +# endif + +# define TRY_MSVC_INVAL \ + do \ + { \ + gl_msvc_inval_ensure_handler (); \ + if (1) +# define CATCH_MSVC_INVAL \ + else +# define DONE_MSVC_INVAL \ + } \ + while (0) + +# else +/* Handling for hairy libraries. */ + +# include <excpt.h> + +/* Gnulib can define its own status codes, as described in the page + "Raising Software Exceptions" on microsoft.com + <https://docs.microsoft.com/en-us/cpp/cpp/raising-software-exceptions>. + Our status codes are composed of + - 0xE0000000, mandatory for all user-defined status codes, + - 0x474E550, a API identifier ("GNU"), + - 0, 1, 2, ..., used to distinguish different status codes from the + same API. */ +# define STATUS_GNULIB_INVALID_PARAMETER (0xE0000000 + 0x474E550 + 0) + +# if defined _MSC_VER +/* A compiler that supports __try/__except, as described in the page + "try-except statement" on microsoft.com + <https://docs.microsoft.com/en-us/cpp/cpp/try-except-statement>. + With __try/__except, we can use the multithread-safe exception handling. */ + +# ifdef __cplusplus +extern "C" { +# endif + +/* Ensure that the invalid parameter handler in installed that raises a + software exception with code STATUS_GNULIB_INVALID_PARAMETER. + Because we assume no other part of the program installs a different + invalid parameter handler, this solution is multithread-safe. */ +extern void gl_msvc_inval_ensure_handler (void); + +# ifdef __cplusplus +} +# endif + +# define TRY_MSVC_INVAL \ + do \ + { \ + gl_msvc_inval_ensure_handler (); \ + __try +# define CATCH_MSVC_INVAL \ + __except (GetExceptionCode () == STATUS_GNULIB_INVALID_PARAMETER \ + ? EXCEPTION_EXECUTE_HANDLER \ + : EXCEPTION_CONTINUE_SEARCH) +# define DONE_MSVC_INVAL \ + } \ + while (0) + +# else +/* Any compiler. + We can only use setjmp/longjmp. */ + +# include <setjmp.h> + +# ifdef __cplusplus +extern "C" { +# endif + +struct gl_msvc_inval_per_thread +{ + /* The restart that will resume execution at the code between + CATCH_MSVC_INVAL and DONE_MSVC_INVAL. It is enabled only between + TRY_MSVC_INVAL and CATCH_MSVC_INVAL. */ + jmp_buf restart; + + /* Tells whether the contents of restart is valid. */ + int restart_valid; +}; + +/* Ensure that the invalid parameter handler in installed that passes + control to the gl_msvc_inval_restart if it is valid, or raises a + software exception with code STATUS_GNULIB_INVALID_PARAMETER otherwise. + Because we assume no other part of the program installs a different + invalid parameter handler, this solution is multithread-safe. */ +extern void gl_msvc_inval_ensure_handler (void); + +/* Return a pointer to the per-thread data for the current thread. */ +extern struct gl_msvc_inval_per_thread *gl_msvc_inval_current (void); + +# ifdef __cplusplus +} +# endif + +# define TRY_MSVC_INVAL \ + do \ + { \ + struct gl_msvc_inval_per_thread *msvc_inval_current; \ + gl_msvc_inval_ensure_handler (); \ + msvc_inval_current = gl_msvc_inval_current (); \ + /* First, initialize gl_msvc_inval_restart. */ \ + if (setjmp (msvc_inval_current->restart) == 0) \ + { \ + /* Then, mark it as valid. */ \ + msvc_inval_current->restart_valid = 1; +# define CATCH_MSVC_INVAL \ + /* Execution completed. \ + Mark gl_msvc_inval_restart as invalid. */ \ + msvc_inval_current->restart_valid = 0; \ + } \ + else \ + { \ + /* Execution triggered an invalid parameter notification. \ + Mark gl_msvc_inval_restart as invalid. */ \ + msvc_inval_current->restart_valid = 0; +# define DONE_MSVC_INVAL \ + } \ + } \ + while (0) + +# endif + +# endif + +#else +/* A platform that does not need to the invalid parameter handler, + or when SANE_LIBRARY_HANDLING is desired. */ + +/* The braces here avoid GCC warnings like + "warning: suggest explicit braces to avoid ambiguous 'else'". */ +# define TRY_MSVC_INVAL \ + do \ + { \ + if (1) +# define CATCH_MSVC_INVAL \ + else +# define DONE_MSVC_INVAL \ + } \ + while (0) + +#endif + +#endif /* _MSVC_INVAL_H */ |