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/stdio/scanf_core/reader.h"
  15 #include "src/stdio/scanf_core/scanf_main.h"
  16
  17 #include <stdio.h>
  18
  19 namespace LIBC_NAMESPACE {
  20
  21 namespace internal {
  22
  23 #ifndef LIBC_COPT_STDIO_USE_SYSTEM_FILE
  24
  25 LIBC_INLINE void flockfile(FILE *f) {
  26   reinterpret_cast<LIBC_NAMESPACE::File *>(f)->lock();
  27 }
  28
  29 LIBC_INLINE void funlockfile(FILE *f) {
  30   reinterpret_cast<LIBC_NAMESPACE::File *>(f)->unlock();
  31 }
  32
  33 LIBC_INLINE int getc(void *f) {
  34   unsigned char c;
  35   auto result =
  36       reinterpret_cast<LIBC_NAMESPACE::File *>(f)->read_unlocked(&c, 1);
  37   size_t r = result.value;
  38   if (result.has_error() || r != 1)
  39     return '\0';
  40
  41   return c;
  42 }
  43
  44 LIBC_INLINE void ungetc(int c, void *f) {
  45   reinterpret_cast<LIBC_NAMESPACE::File *>(f)->ungetc_unlocked(c);
  46 }
  47
  48 LIBC_INLINE int ferror_unlocked(FILE *f) {
  49   return reinterpret_cast<LIBC_NAMESPACE::File *>(f)->error_unlocked();
  50 }
  51
  52 #else // defined(LIBC_COPT_STDIO_USE_SYSTEM_FILE)
  53
  54 // Since ungetc_unlocked isn't always available, we don't acquire the lock for
  55 // system files.
  56 LIBC_INLINE void flockfile(::FILE *) { return; }
  57
  58 LIBC_INLINE void funlockfile(::FILE *) { return; }
  59
  60 LIBC_INLINE int getc(void *f) { return ::getc(reinterpret_cast<::FILE *>(f)); }
  61
  62 LIBC_INLINE void ungetc(int c, void *f) {
  63   ::ungetc(c, reinterpret_cast<::FILE *>(f));
  64 }
  65
  66 LIBC_INLINE int ferror_unlocked(::FILE *f) { return ::ferror(f); }
  67
  68 #endif // LIBC_COPT_STDIO_USE_SYSTEM_FILE
  69
  70 } // namespace internal
  71
  72 namespace scanf_core {
  73
  74 LIBC_INLINE int vfscanf_internal(::FILE *__restrict stream,
  75                                  const char *__restrict format,
  76                                  internal::ArgList &args) {
  77   internal::flockfile(stream);
  78   scanf_core::Reader reader(stream, &internal::getc, internal::ungetc);
  79   int retval = scanf_core::scanf_main(&reader, format, args);
  80   if (retval == 0 && internal::ferror_unlocked(stream))
  81     retval = EOF;
  82   internal::funlockfile(stream);
  83
  84   return retval;
  85 }
  86 } // namespace scanf_core
  87 } // namespace LIBC_NAMESPACE
  88
  89 #endif // LLVM_LIBC_SRC_STDIO_SCANF_CORE_VFSCANF_INTERNAL_H