stdio.h (2931B) - Raw
1 //===-- Wrapper for C standard stdio.h declarations on the GPU ------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #if !defined(_OPENMP) && !defined(__HIP__) && !defined(__CUDA__) 10 #error "This file is for GPU offloading compilation only" 11 #endif 12 13 #include_next <stdio.h> 14 15 // In some old versions of glibc, other standard headers sometimes define 16 // special macros (e.g., __need_FILE) before including stdio.h to cause stdio.h 17 // to produce special definitions. Future includes of stdio.h when those 18 // special macros are undefined are expected to produce the normal definitions 19 // from stdio.h. 20 // 21 // We do not apply our include guard (__CLANG_LLVM_LIBC_WRAPPERS_STDIO_H__) 22 // unconditionally to the above include_next. Otherwise, after an occurrence of 23 // the first glibc stdio.h use case described above, the include_next would be 24 // skipped for remaining includes of stdio.h, leaving required symbols 25 // undefined. 26 // 27 // We make the following assumptions to handle all use cases: 28 // 29 // 1. If the above include_next produces special glibc definitions, then (a) it 30 // does not produce the normal definitions that we must intercept below, (b) 31 // the current file was included from a glibc header that already defined 32 // __GLIBC__ (usually by including glibc's <features.h>), and (c) the above 33 // include_next does not define _STDIO_H. In that case, we skip the rest of 34 // the current file and don't guard against future includes. 35 // 2. If the above include_next produces the normal stdio.h definitions, then 36 // either (a) __GLIBC__ is not defined because C headers are from some other 37 // libc implementation or (b) the above include_next defines _STDIO_H to 38 // prevent the above include_next from having any effect in the future. 39 #if !defined(__GLIBC__) || defined(_STDIO_H) 40 41 #ifndef __CLANG_LLVM_LIBC_WRAPPERS_STDIO_H__ 42 #define __CLANG_LLVM_LIBC_WRAPPERS_STDIO_H__ 43 44 #if __has_include(<llvm-libc-decls/stdio.h>) 45 46 #if defined(__HIP__) || defined(__CUDA__) 47 #define __LIBC_ATTRS __attribute__((device)) 48 #endif 49 50 // Some headers provide these as macros. Temporarily undefine them so they do 51 // not conflict with any definitions for the GPU. 52 53 #pragma push_macro("stdout") 54 #pragma push_macro("stdin") 55 #pragma push_macro("stderr") 56 57 #undef stdout 58 #undef stderr 59 #undef stdin 60 61 #pragma omp begin declare target 62 63 #include <llvm-libc-decls/stdio.h> 64 65 #pragma omp end declare target 66 67 #undef __LIBC_ATTRS 68 69 // Restore the original macros when compiling on the host. 70 #if !defined(__NVPTX__) && !defined(__AMDGPU__) 71 #pragma pop_macro("stdout") 72 #pragma pop_macro("stderr") 73 #pragma pop_macro("stdin") 74 #endif 75 76 #endif 77 78 #endif // __CLANG_LLVM_LIBC_WRAPPERS_STDIO_H__ 79 80 #endif