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Diffstat (limited to 'cross/lib/vla.h')
-rw-r--r-- | cross/lib/vla.h | 53 |
1 files changed, 0 insertions, 53 deletions
diff --git a/cross/lib/vla.h b/cross/lib/vla.h deleted file mode 100644 index 55f112a060a..00000000000 --- a/cross/lib/vla.h +++ /dev/null @@ -1,53 +0,0 @@ -/* vla.h - variable length arrays - - Copyright 2014-2023 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 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 <https://www.gnu.org/licenses/>. - - Written by Paul Eggert. */ - -/* The VLA_ELEMS macro does not allocate variable-length arrays (VLAs), - so it does not have the security or performance issues commonly - associated with VLAs. VLA_ELEMS is for exploiting a C11 feature - where a function can start like this: - - double scan_array (int n, double v[static n]) - - to require a caller to pass a vector V with at least N elements; - this allows better static checking and performance in some cases. - In C11 this feature means that V is a VLA, so the feature is - supported only if __STDC_NO_VLA__ is defined, and for compatibility - to platforms that do not support VLAs, VLA_ELEMS (n) expands to - nothing when __STDC_NO_VLA__ is not defined. */ - -/* A function's argument must point to an array with at least N elements. - Example: 'int main (int argc, char *argv[VLA_ELEMS (argc)]);'. */ - -#ifdef __STDC_NO_VLA__ -# define VLA_ELEMS(n) -#else -# define VLA_ELEMS(n) static n -#endif - -/* Although C99 requires support for variable-length arrays (VLAs), - some C compilers never supported VLAs and VLAs are optional in C11. - VLAs are controversial because their allocation may be unintended - or awkward to support, and large VLAs might cause security or - performance problems. GCC can diagnose the use of VLAs via the - -Wvla and -Wvla-larger-than warnings options, and defining the - macro GNULIB_NO_VLA disables the allocation of VLAs in Gnulib code. - - The VLA_ELEMS macro is unaffected by GNULIB_NO_VLA, since it does - not allocate VLAs. Programs that use VLA_ELEMS should be compiled - with 'gcc -Wvla-larger-than' instead of with 'gcc -Wvla'. */ |