libc/src/stdio/scanf_core/vfscanf_internal.h

   1 //===-- Internal implementation header of vfscanf ---------------*- C++ -*-===//
   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 #ifndef LLVM_LIBC_SRC_STDIO_SCANF_CORE_VFSCANF_INTERNAL_H
  10 #define LLVM_LIBC_SRC_STDIO_SCANF_CORE_VFSCANF_INTERNAL_H
  11
  12 #include "src/__support/File/file.h"
  13 #include "src/__support/arg_list.h"
  14 #include "src/__support/macros/config.h"
  15 #include "src/__support/macros/properties/architectures.h"
  16 #include "src/stdio/scanf_core/reader.h"
  17 #include "src/stdio/scanf_core/scanf_main.h"
  18
  19 #if defined(LIBC_TARGET_ARCH_IS_GPU)
  20 #include "src/stdio/ferror.h"
  21 #include "src/stdio/getc.h"
  22 #include "src/stdio/ungetc.h"
  23 #endif
  24
  25 #include "hdr/types/FILE.h"
  26 #include <stddef.h>
  27
  28 namespace LIBC_NAMESPACE_DECL {
  29
  30 namespace internal {
  31
  32 #if defined(LIBC_TARGET_ARCH_IS_GPU)
  33 // The GPU build provides FILE access through the host operating system's
  34 // library. So here we simply use the public entrypoints like in the SYSTEM_FILE
  35 // interface. Entrypoints should normally not call others, this is an exception.
  36 // FIXME: We do not acquire any locks here, so this is not thread safe.
  37 LIBC_INLINE void flockfile(::FILE *) { return; }
  38
  39 LIBC_INLINE void funlockfile(::FILE *) { return; }
  40
  41 LIBC_INLINE int getc(void *f) {
  42   return LIBC_NAMESPACE::getc(reinterpret_cast<::FILE *>(f));
  43 }
  44
  45 LIBC_INLINE void ungetc(int c, void *f) {
  46   LIBC_NAMESPACE::ungetc(c, reinterpret_cast<::FILE *>(f));
  47 }
  48
  49 LIBC_INLINE int ferror_unlocked(::FILE *f) { return LIBC_NAMESPACE::ferror(f); }
  50
  51 #elif !defined(LIBC_COPT_STDIO_USE_SYSTEM_FILE)
  52
  53 LIBC_INLINE void flockfile(FILE *f) {
  54   reinterpret_cast<LIBC_NAMESPACE::File *>(f)->lock();
  55 }
  56
  57 LIBC_INLINE void funlockfile(FILE *f) {
  58   reinterpret_cast<LIBC_NAMESPACE::File *>(f)->unlock();
  59 }
  60
  61 LIBC_INLINE int getc(void *f) {
  62   unsigned char c;
  63   auto result =
  64       reinterpret_cast<LIBC_NAMESPACE::File *>(f)->read_unlocked(&c, 1);
  65   size_t r = result.value;
  66   if (result.has_error() || r != 1)
  67     return '\0';
  68
  69   return c;
  70 }
  71
  72 LIBC_INLINE void ungetc(int c, void *f) {
  73   reinterpret_cast<LIBC_NAMESPACE::File *>(f)->ungetc_unlocked(c);
  74 }
  75
  76 LIBC_INLINE int ferror_unlocked(FILE *f) {
  77   return reinterpret_cast<LIBC_NAMESPACE::File *>(f)->error_unlocked();
  78 }
  79
  80 #else // defined(LIBC_COPT_STDIO_USE_SYSTEM_FILE)
  81
  82 // Since ungetc_unlocked isn't always available, we don't acquire the lock for
  83 // system files.
  84 LIBC_INLINE void flockfile(::FILE *) { return; }
  85
  86 LIBC_INLINE void funlockfile(::FILE *) { return; }
  87
  88 LIBC_INLINE int getc(void *f) { return ::getc(reinterpret_cast<::FILE *>(f)); }
  89
  90 LIBC_INLINE void ungetc(int c, void *f) {
  91   ::ungetc(c, reinterpret_cast<::FILE *>(f));
  92 }
  93
  94 LIBC_INLINE int ferror_unlocked(::FILE *f) { return ::ferror(f); }
  95
  96 #endif // LIBC_COPT_STDIO_USE_SYSTEM_FILE
  97
  98 } // namespace internal
  99
 100 namespace scanf_core {
 101
 102 LIBC_INLINE int vfscanf_internal(::FILE *__restrict stream,
 103                                  const char *__restrict format,
 104                                  internal::ArgList &args) {
 105   internal::flockfile(stream);
 106   scanf_core::Reader reader(stream, &internal::getc, internal::ungetc);
 107   int retval = scanf_core::scanf_main(&reader, format, args);
 108   if (retval == 0 && internal::ferror_unlocked(stream))
 109     retval = EOF;
 110   internal::funlockfile(stream);
 111
 112   return retval;
 113 }
 114 } // namespace scanf_core
 115 } // namespace LIBC_NAMESPACE_DECL
 116
 117 #endif // LLVM_LIBC_SRC_STDIO_SCANF_CORE_VFSCANF_INTERNAL_H