compiler-rt/lib/gwp_asan/optional/printf.h

   1 //===-- printf.h ------------------------------------------------*- 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 GWP_ASAN_OPTIONAL_PRINTF_H_
  10 #define GWP_ASAN_OPTIONAL_PRINTF_H_
  11
  12 namespace gwp_asan {
  13
  14 // ================================ Requirements ===============================
  15 // This function is required to be provided by the supporting allocator iff the
  16 // allocator wants to use any of the optional components.
  17 // ================================ Description ================================
  18 // This function shall produce output according to a strict subset of the C
  19 // standard library's printf() family. This function must support printing the
  20 // following formats:
  21 //   1. integers: "%([0-9]*)?(z|ll)?{d,u,x,X}"
  22 //   2. pointers: "%p"
  23 //   3. strings:  "%[-]([0-9]*)?(\\.\\*)?s"
  24 //   4. chars:    "%c"
  25 // This function must be implemented in a signal-safe manner, and thus must not
  26 // malloc().
  27 // =================================== Notes ===================================
  28 // This function has a slightly different signature than the C standard
  29 // library's printf(). Notably, it returns 'void' rather than 'int'.
  30 typedef void (*Printf_t)(const char *Format, ...);
  31
  32 } // namespace gwp_asan
  33 #endif // GWP_ASAN_OPTIONAL_PRINTF_H_