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Cleanup fuzzing mode

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This commit is contained in:
Victor Zverovich 2022-03-18 11:18:03 -07:00
parent 4e39e13085
commit 3c61799fbf
2 changed files with 10 additions and 25 deletions
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21
include/fmt/format.h
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@ -255,6 +255,13 @@ FMT_END_NAMESPACE
FMT_BEGIN_NAMESPACE FMT_BEGIN_NAMESPACE
namespace detail { namespace detail {
FMT_CONSTEXPR inline void abort_fuzzing_if(bool condition) {
ignore_unused(condition);
#ifdef FMT_FUZZ
if (condition) throw std::runtime_error("fuzzing limit reached");
#endif
}
template <typename Streambuf> class formatbuf : public Streambuf { template <typename Streambuf> class formatbuf : public Streambuf {
private: private:
using char_type = typename Streambuf::char_type; using char_type = typename Streambuf::char_type;
@ -837,9 +844,7 @@ class basic_memory_buffer final : public detail::buffer<T> {
template <typename T, size_t SIZE, typename Allocator> template <typename T, size_t SIZE, typename Allocator>
FMT_CONSTEXPR20 void basic_memory_buffer<T, SIZE, Allocator>::grow( FMT_CONSTEXPR20 void basic_memory_buffer<T, SIZE, Allocator>::grow(
size_t size) { size_t size) {
#ifdef FMT_FUZZ detail::abort_fuzzing_if(size > 5000);
if (size > 5000) throw std::runtime_error("fuzz mode - won't grow that much");
#endif
const size_t max_size = std::allocator_traits<Allocator>::max_size(alloc_); const size_t max_size = std::allocator_traits<Allocator>::max_size(alloc_);
size_t old_capacity = this->capacity(); size_t old_capacity = this->capacity();
size_t new_capacity = old_capacity + old_capacity / 2; size_t new_capacity = old_capacity + old_capacity / 2;
@ -1367,10 +1372,7 @@ auto snprintf_float(T value, int precision, float_specs specs,
for (;;) { for (;;) {
auto begin = buf.data() + offset; auto begin = buf.data() + offset;
auto capacity = buf.capacity() - offset; auto capacity = buf.capacity() - offset;
#ifdef FMT_FUZZ abort_fuzzing_if(precision > 100000);
if (precision > 100000)
throw std::runtime_error("fuzz mode: avoid large allocation in snprintf");
#endif
// Suppress the warning about a nonliteral format string. // Suppress the warning about a nonliteral format string.
// Cannot use auto because of a bug in MinGW (#1532). // Cannot use auto because of a bug in MinGW (#1532).
int (*snprintf_ptr)(char*, size_t, const char*, ...) = FMT_SNPRINTF; int (*snprintf_ptr)(char*, size_t, const char*, ...) = FMT_SNPRINTF;
@ -2203,10 +2205,7 @@ FMT_CONSTEXPR20 auto do_write_float(OutputIt out, const DecimalFP& fp,
// 1234e5 -> 123400000[.0+] // 1234e5 -> 123400000[.0+]
size += to_unsigned(fp.exponent); size += to_unsigned(fp.exponent);
int num_zeros = fspecs.precision - exp; int num_zeros = fspecs.precision - exp;
#ifdef FMT_FUZZ abort_fuzzing_if(num_zeros > 5000);
if (num_zeros > 5000)
throw std::runtime_error("fuzz mode - avoiding excessive cpu use");
#endif
if (fspecs.showpoint) { if (fspecs.showpoint) {
++size; ++size;
if (num_zeros <= 0 && fspecs.format != float_format::fixed) num_zeros = 1; if (num_zeros <= 0 && fspecs.format != float_format::fixed) num_zeros = 1;

14
src/format.cc
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@ -56,20 +56,6 @@ constexpr const char basic_data<T>::right_padding_shifts[];
template <typename T> constexpr const unsigned basic_data<T>::prefixes[]; template <typename T> constexpr const unsigned basic_data<T>::prefixes[];
#endif #endif
template <typename T>
int format_float(char* buf, std::size_t size, const char* format, int precision,
T value) {
#ifdef FMT_FUZZ
if (precision > 100000)
throw std::runtime_error(
"fuzz mode - avoid large allocation inside snprintf");
#endif
// Suppress the warning about nonliteral format string.
int (*snprintf_ptr)(char*, size_t, const char*, ...) = FMT_SNPRINTF;
return precision < 0 ? snprintf_ptr(buf, size, format, value)
: snprintf_ptr(buf, size, format, precision, value);
}
template FMT_API dragonbox::decimal_fp<float> dragonbox::to_decimal( template FMT_API dragonbox::decimal_fp<float> dragonbox::to_decimal(
float x) noexcept; float x) noexcept;
template FMT_API dragonbox::decimal_fp<double> dragonbox::to_decimal( template FMT_API dragonbox::decimal_fp<double> dragonbox::to_decimal(