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//===-- printf_parser_fuzz.cpp --------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
///
/// Fuzzing test for llvm-libc qsort implementation.
///
//===----------------------------------------------------------------------===//
#ifndef LIBC_COPT_MOCK_ARG_LIST
#error The printf Parser Fuzzer must be compiled with LIBC_COPT_MOCK_ARG_LIST, and the parser itself must also be compiled with that option when it's linked against the fuzzer.
#endif
#include "src/__support/arg_list.h"
#include "src/stdio/printf_core/parser.h"
#include <stdarg.h>
#include <stdint.h>
using namespace __llvm_libc;
// The design for the printf parser fuzzer is fairly simple. The parser uses a
// mock arg list that will never fail, and is passed a randomized string. The
// format sections it outputs are checked against a count of the number of '%'
// signs are in the original string. This is a fairly basic test, and the main
// intent is to run this under sanitizers, which will check for buffer overruns.
extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
char *in_str = new char[size + 1];
for (size_t i = 0; i < size; ++i)
in_str[i] = data[i];
in_str[size] = '\0';
auto mock_arg_list = internal::MockArgList();
auto parser = printf_core::Parser(in_str, mock_arg_list);
int str_percent_count = 0;
for (size_t i = 0; i < size && in_str[i] != '\0'; ++i) {
if (in_str[i] == '%') {
++str_percent_count;
}
}
int section_percent_count = 0;
for (printf_core::FormatSection cur_section = parser.get_next_section();
!cur_section.raw_string.empty();
cur_section = parser.get_next_section()) {
if (cur_section.has_conv) {
++section_percent_count;
if (cur_section.conv_name == '%') {
++section_percent_count;
}
} else if (cur_section.raw_string[0] == '%') {
// If the conversion would be undefined, it's instead raw, but it still
// starts with a %.
++section_percent_count;
}
}
if (str_percent_count != section_percent_count) {
__builtin_trap();
}
delete[] in_str;
return 0;
}
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