https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69680
Bug ID: 69680 Summary: stdlib.h does not declare aligned_alloc Product: gcc Version: 5.3.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: jeff.science at gmail dot com Target Milestone: --- When I use aligned_alloc, I am told to include stdlib.h to provide a declaration, but I have already done so. VERSION $ gcc-5 -v Using built-in specs. COLLECT_GCC=gcc-5 COLLECT_LTO_WRAPPER=/usr/local/Cellar/gcc/5.3.0/libexec/gcc/x86_64-apple-darwin14.5.0/5.3.0/lto-wrapper Target: x86_64-apple-darwin14.5.0 Configured with: ../configure --build=x86_64-apple-darwin14.5.0 --prefix=/usr/local/Cellar/gcc/5.3.0 --libdir=/usr/local/Cellar/gcc/5.3.0/lib/gcc/5 --enable-languages=c,c++,objc,obj-c++,fortran --program-suffix=-5 --with-gmp=/usr/local/opt/gmp --with-mpfr=/usr/local/opt/mpfr --with-mpc=/usr/local/opt/libmpc --with-isl=/usr/local/opt/isl --with-system-zlib --enable-libstdcxx-time=yes --enable-stage1-checking --enable-checking=release --enable-lto --with-build-config=bootstrap-debug --disable-werror --with-pkgversion='Homebrew gcc 5.3.0 --without-multilib' --with-bugurl=https://github.com/Homebrew/homebrew/issues --enable-plugin --disable-nls --disable-multilib Thread model: posix gcc version 5.3.0 (Homebrew gcc 5.3.0 --without-multilib) COMPILATION $ gcc-5 -c aligned_alloc.c aligned_alloc.c: In function 'my_malloc': aligned_alloc.c:5:12: warning: implicit declaration of function 'aligned_alloc' [-Wimplicit-function-declaration] return aligned_alloc(64,bytes); ^ aligned_alloc.c:5:12: warning: incompatible implicit declaration of built-in function 'aligned_alloc' aligned_alloc.c:5:12: note: include '<stdlib.h>' or provide a declaration of 'aligned_alloc' CODE $ cat aligned_alloc.c #include <stdlib.h> #if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L) void* my_malloc(size_t bytes) { return aligned_alloc(64,bytes); } #else #error Pointless #endif EXTRA It seems that none of the GCC 5.3.0 headers declare this function... $ find /usr/local/Cellar/gcc/5.3.0/ -name "*.h" -exec grep -H aligned_alloc {} ";"