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abseil-cpp/absl/strings/internal/str_format/convert_test.cc

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#include <errno.h>
#include <stdarg.h>
#include <stdio.h>
#include <cctype>
#include <cmath>
#include <limits>
#include <string>
#include <thread> // NOLINT
#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "absl/base/internal/raw_logging.h"
#include "absl/strings/internal/str_format/bind.h"
#include "absl/types/optional.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace str_format_internal {
namespace {
template <typename T, size_t N>
size_t ArraySize(T (&)[N]) {
return N;
}
std::string LengthModFor(float) { return ""; }
std::string LengthModFor(double) { return ""; }
std::string LengthModFor(long double) { return "L"; }
std::string LengthModFor(char) { return "hh"; }
std::string LengthModFor(signed char) { return "hh"; }
std::string LengthModFor(unsigned char) { return "hh"; }
std::string LengthModFor(short) { return "h"; } // NOLINT
std::string LengthModFor(unsigned short) { return "h"; } // NOLINT
std::string LengthModFor(int) { return ""; }
std::string LengthModFor(unsigned) { return ""; }
std::string LengthModFor(long) { return "l"; } // NOLINT
std::string LengthModFor(unsigned long) { return "l"; } // NOLINT
std::string LengthModFor(long long) { return "ll"; } // NOLINT
std::string LengthModFor(unsigned long long) { return "ll"; } // NOLINT
std::string EscCharImpl(int v) {
if (std::isprint(static_cast<unsigned char>(v))) {
return std::string(1, static_cast<char>(v));
}
char buf[64];
int n = snprintf(buf, sizeof(buf), "\\%#.2x",
static_cast<unsigned>(v & 0xff));
assert(n > 0 && n < sizeof(buf));
return std::string(buf, n);
}
std::string Esc(char v) { return EscCharImpl(v); }
std::string Esc(signed char v) { return EscCharImpl(v); }
std::string Esc(unsigned char v) { return EscCharImpl(v); }
template <typename T>
std::string Esc(const T &v) {
std::ostringstream oss;
oss << v;
return oss.str();
}
void StrAppendV(std::string *dst, const char *format, va_list ap) {
// First try with a small fixed size buffer
static const int kSpaceLength = 1024;
char space[kSpaceLength];
// It's possible for methods that use a va_list to invalidate
// the data in it upon use. The fix is to make a copy
// of the structure before using it and use that copy instead.
va_list backup_ap;
va_copy(backup_ap, ap);
int result = vsnprintf(space, kSpaceLength, format, backup_ap);
va_end(backup_ap);
if (result < kSpaceLength) {
if (result >= 0) {
// Normal case -- everything fit.
dst->append(space, result);
return;
}
if (result < 0) {
// Just an error.
return;
}
}
// Increase the buffer size to the size requested by vsnprintf,
// plus one for the closing \0.
int length = result + 1;
char *buf = new char[length];
// Restore the va_list before we use it again
va_copy(backup_ap, ap);
result = vsnprintf(buf, length, format, backup_ap);
va_end(backup_ap);
if (result >= 0 && result < length) {
// It fit
dst->append(buf, result);
}
delete[] buf;
}
void StrAppend(std::string *out, const char *format, ...) {
va_list ap;
va_start(ap, format);
StrAppendV(out, format, ap);
va_end(ap);
}
std::string StrPrint(const char *format, ...) {
va_list ap;
va_start(ap, format);
std::string result;
StrAppendV(&result, format, ap);
va_end(ap);
return result;
}
class FormatConvertTest : public ::testing::Test { };
template <typename T>
void TestStringConvert(const T& str) {
const FormatArgImpl args[] = {FormatArgImpl(str)};
struct Expectation {
const char *out;
const char *fmt;
};
const Expectation kExpect[] = {
{"hello", "%1$s" },
{"", "%1$.s" },
{"", "%1$.0s" },
{"h", "%1$.1s" },
{"he", "%1$.2s" },
{"hello", "%1$.10s" },
{" hello", "%1$6s" },
{" he", "%1$5.2s" },
{"he ", "%1$-5.2s" },
{"hello ", "%1$-6.10s" },
};
for (const Expectation &e : kExpect) {
UntypedFormatSpecImpl format(e.fmt);
EXPECT_EQ(e.out, FormatPack(format, absl::MakeSpan(args)));
}
}
TEST_F(FormatConvertTest, BasicString) {
TestStringConvert("hello"); // As char array.
TestStringConvert(static_cast<const char*>("hello"));
TestStringConvert(std::string("hello"));
TestStringConvert(string_view("hello"));
}
TEST_F(FormatConvertTest, NullString) {
const char* p = nullptr;
UntypedFormatSpecImpl format("%s");
EXPECT_EQ("", FormatPack(format, {FormatArgImpl(p)}));
}
TEST_F(FormatConvertTest, StringPrecision) {
// We cap at the precision.
char c = 'a';
const char* p = &c;
UntypedFormatSpecImpl format("%.1s");
EXPECT_EQ("a", FormatPack(format, {FormatArgImpl(p)}));
// We cap at the NUL-terminator.
p = "ABC";
UntypedFormatSpecImpl format2("%.10s");
EXPECT_EQ("ABC", FormatPack(format2, {FormatArgImpl(p)}));
}
// Pointer formatting is implementation defined. This checks that the argument
// can be matched to `ptr`.
MATCHER_P(MatchesPointerString, ptr, "") {
if (ptr == nullptr && arg == "(nil)") {
return true;
}
void* parsed = nullptr;
if (sscanf(arg.c_str(), "%p", &parsed) != 1) {
ABSL_RAW_LOG(FATAL, "Could not parse %s", arg.c_str());
}
return ptr == parsed;
}
TEST_F(FormatConvertTest, Pointer) {
static int x = 0;
const int *xp = &x;
char c = 'h';
char *mcp = &c;
const char *cp = "hi";
const char *cnil = nullptr;
const int *inil = nullptr;
using VoidF = void (*)();
VoidF fp = [] {}, fnil = nullptr;
volatile char vc;
volatile char *vcp = &vc;
volatile char *vcnil = nullptr;
const FormatArgImpl args_array[] = {
FormatArgImpl(xp), FormatArgImpl(cp), FormatArgImpl(inil),
FormatArgImpl(cnil), FormatArgImpl(mcp), FormatArgImpl(fp),
FormatArgImpl(fnil), FormatArgImpl(vcp), FormatArgImpl(vcnil),
};
auto args = absl::MakeConstSpan(args_array);
EXPECT_THAT(FormatPack(UntypedFormatSpecImpl("%p"), args),
MatchesPointerString(&x));
EXPECT_THAT(FormatPack(UntypedFormatSpecImpl("%20p"), args),
MatchesPointerString(&x));
EXPECT_THAT(FormatPack(UntypedFormatSpecImpl("%.1p"), args),
MatchesPointerString(&x));
EXPECT_THAT(FormatPack(UntypedFormatSpecImpl("%.20p"), args),
MatchesPointerString(&x));
EXPECT_THAT(FormatPack(UntypedFormatSpecImpl("%30.20p"), args),
MatchesPointerString(&x));
EXPECT_THAT(FormatPack(UntypedFormatSpecImpl("%-p"), args),
MatchesPointerString(&x));
EXPECT_THAT(FormatPack(UntypedFormatSpecImpl("%-20p"), args),
MatchesPointerString(&x));
EXPECT_THAT(FormatPack(UntypedFormatSpecImpl("%-.1p"), args),
MatchesPointerString(&x));
EXPECT_THAT(FormatPack(UntypedFormatSpecImpl("%.20p"), args),
MatchesPointerString(&x));
EXPECT_THAT(FormatPack(UntypedFormatSpecImpl("%-30.20p"), args),
MatchesPointerString(&x));
// const char*
EXPECT_THAT(FormatPack(UntypedFormatSpecImpl("%2$p"), args),
MatchesPointerString(cp));
// null const int*
EXPECT_THAT(FormatPack(UntypedFormatSpecImpl("%3$p"), args),
MatchesPointerString(nullptr));
// null const char*
EXPECT_THAT(FormatPack(UntypedFormatSpecImpl("%4$p"), args),
MatchesPointerString(nullptr));
// nonconst char*
EXPECT_THAT(FormatPack(UntypedFormatSpecImpl("%5$p"), args),
MatchesPointerString(mcp));
// function pointers
EXPECT_THAT(FormatPack(UntypedFormatSpecImpl("%6$p"), args),
MatchesPointerString(reinterpret_cast<const void*>(fp)));
EXPECT_THAT(
FormatPack(UntypedFormatSpecImpl("%8$p"), args),
MatchesPointerString(reinterpret_cast<volatile const void *>(vcp)));
// null function pointers
EXPECT_THAT(FormatPack(UntypedFormatSpecImpl("%7$p"), args),
MatchesPointerString(nullptr));
EXPECT_THAT(FormatPack(UntypedFormatSpecImpl("%9$p"), args),
MatchesPointerString(nullptr));
}
struct Cardinal {
enum Pos { k1 = 1, k2 = 2, k3 = 3 };
enum Neg { kM1 = -1, kM2 = -2, kM3 = -3 };
};
TEST_F(FormatConvertTest, Enum) {
const Cardinal::Pos k3 = Cardinal::k3;
const Cardinal::Neg km3 = Cardinal::kM3;
const FormatArgImpl args[] = {FormatArgImpl(k3), FormatArgImpl(km3)};
UntypedFormatSpecImpl format("%1$d");
UntypedFormatSpecImpl format2("%2$d");
EXPECT_EQ("3", FormatPack(format, absl::MakeSpan(args)));
EXPECT_EQ("-3", FormatPack(format2, absl::MakeSpan(args)));
}
template <typename T>
class TypedFormatConvertTest : public FormatConvertTest { };
TYPED_TEST_SUITE_P(TypedFormatConvertTest);
std::vector<std::string> AllFlagCombinations() {
const char kFlags[] = {'-', '#', '0', '+', ' '};
std::vector<std::string> result;
for (size_t fsi = 0; fsi < (1ull << ArraySize(kFlags)); ++fsi) {
std::string flag_set;
for (size_t fi = 0; fi < ArraySize(kFlags); ++fi)
if (fsi & (1ull << fi))
flag_set += kFlags[fi];
result.push_back(flag_set);
}
return result;
}
TYPED_TEST_P(TypedFormatConvertTest, AllIntsWithFlags) {
typedef TypeParam T;
typedef typename std::make_unsigned<T>::type UnsignedT;
using remove_volatile_t = typename std::remove_volatile<T>::type;
const T kMin = std::numeric_limits<remove_volatile_t>::min();
const T kMax = std::numeric_limits<remove_volatile_t>::max();
const T kVals[] = {
remove_volatile_t(1),
remove_volatile_t(2),
remove_volatile_t(3),
remove_volatile_t(123),
remove_volatile_t(-1),
remove_volatile_t(-2),
remove_volatile_t(-3),
remove_volatile_t(-123),
remove_volatile_t(0),
kMax - remove_volatile_t(1),
kMax,
kMin + remove_volatile_t(1),
kMin,
};
const char kConvChars[] = {'d', 'i', 'u', 'o', 'x', 'X'};
const std::string kWid[] = {"", "4", "10"};
const std::string kPrec[] = {"", ".", ".0", ".4", ".10"};
const std::vector<std::string> flag_sets = AllFlagCombinations();
for (size_t vi = 0; vi < ArraySize(kVals); ++vi) {
const T val = kVals[vi];
SCOPED_TRACE(Esc(val));
const FormatArgImpl args[] = {FormatArgImpl(val)};
for (size_t ci = 0; ci < ArraySize(kConvChars); ++ci) {
const char conv_char = kConvChars[ci];
for (size_t fsi = 0; fsi < flag_sets.size(); ++fsi) {
const std::string &flag_set = flag_sets[fsi];
for (size_t wi = 0; wi < ArraySize(kWid); ++wi) {
const std::string &wid = kWid[wi];
for (size_t pi = 0; pi < ArraySize(kPrec); ++pi) {
const std::string &prec = kPrec[pi];
const bool is_signed_conv = (conv_char == 'd' || conv_char == 'i');
const bool is_unsigned_to_signed =
!std::is_signed<T>::value && is_signed_conv;
// Don't consider sign-related flags '+' and ' ' when doing
// unsigned to signed conversions.
if (is_unsigned_to_signed &&
flag_set.find_first_of("+ ") != std::string::npos) {
continue;
}
std::string new_fmt("%");
new_fmt += flag_set;
new_fmt += wid;
new_fmt += prec;
// old and new always agree up to here.
std::string old_fmt = new_fmt;
new_fmt += conv_char;
std::string old_result;
if (is_unsigned_to_signed) {
// don't expect agreement on unsigned formatted as signed,
// as printf can't do that conversion properly. For those
// cases, we do expect agreement with printf with a "%u"
// and the unsigned equivalent of 'val'.
UnsignedT uval = val;
old_fmt += LengthModFor(uval);
old_fmt += "u";
old_result = StrPrint(old_fmt.c_str(), uval);
} else {
old_fmt += LengthModFor(val);
old_fmt += conv_char;
old_result = StrPrint(old_fmt.c_str(), val);
}
SCOPED_TRACE(std::string() + " old_fmt: \"" + old_fmt +
"\"'"
" new_fmt: \"" +
new_fmt + "\"");
UntypedFormatSpecImpl format(new_fmt);
EXPECT_EQ(old_result, FormatPack(format, absl::MakeSpan(args)));
}
}
}
}
}
}
TYPED_TEST_P(TypedFormatConvertTest, Char) {
typedef TypeParam T;
using remove_volatile_t = typename std::remove_volatile<T>::type;
static const T kMin = std::numeric_limits<remove_volatile_t>::min();
static const T kMax = std::numeric_limits<remove_volatile_t>::max();
T kVals[] = {
remove_volatile_t(1), remove_volatile_t(2), remove_volatile_t(10),
remove_volatile_t(-1), remove_volatile_t(-2), remove_volatile_t(-10),
remove_volatile_t(0),
kMin + remove_volatile_t(1), kMin,
kMax - remove_volatile_t(1), kMax
};
for (const T &c : kVals) {
const FormatArgImpl args[] = {FormatArgImpl(c)};
UntypedFormatSpecImpl format("%c");
EXPECT_EQ(StrPrint("%c", c), FormatPack(format, absl::MakeSpan(args)));
}
}
REGISTER_TYPED_TEST_CASE_P(TypedFormatConvertTest, AllIntsWithFlags, Char);
typedef ::testing::Types<
int, unsigned, volatile int,
short, unsigned short,
long, unsigned long,
long long, unsigned long long,
signed char, unsigned char, char>
AllIntTypes;
INSTANTIATE_TYPED_TEST_CASE_P(TypedFormatConvertTestWithAllIntTypes,
TypedFormatConvertTest, AllIntTypes);
TEST_F(FormatConvertTest, VectorBool) {
// Make sure vector<bool>'s values behave as bools.
std::vector<bool> v = {true, false};
const std::vector<bool> cv = {true, false};
EXPECT_EQ("1,0,1,0",
FormatPack(UntypedFormatSpecImpl("%d,%d,%d,%d"),
absl::Span<const FormatArgImpl>(
{FormatArgImpl(v[0]), FormatArgImpl(v[1]),
FormatArgImpl(cv[0]), FormatArgImpl(cv[1])})));
}
TEST_F(FormatConvertTest, Int128) {
absl::int128 positive = static_cast<absl::int128>(0x1234567890abcdef) * 1979;
absl::int128 negative = -positive;
absl::int128 max = absl::Int128Max(), min = absl::Int128Min();
const FormatArgImpl args[] = {FormatArgImpl(positive),
FormatArgImpl(negative), FormatArgImpl(max),
FormatArgImpl(min)};
struct Case {
const char* format;
const char* expected;
} cases[] = {
{"%1$d", "2595989796776606496405"},
{"%1$30d", " 2595989796776606496405"},
{"%1$-30d", "2595989796776606496405 "},
{"%1$u", "2595989796776606496405"},
{"%1$x", "8cba9876066020f695"},
{"%2$d", "-2595989796776606496405"},
{"%2$30d", " -2595989796776606496405"},
{"%2$-30d", "-2595989796776606496405 "},
{"%2$u", "340282366920938460867384810655161715051"},
{"%2$x", "ffffffffffffff73456789f99fdf096b"},
{"%3$d", "170141183460469231731687303715884105727"},
{"%3$u", "170141183460469231731687303715884105727"},
{"%3$x", "7fffffffffffffffffffffffffffffff"},
{"%4$d", "-170141183460469231731687303715884105728"},
{"%4$x", "80000000000000000000000000000000"},
};
for (auto c : cases) {
UntypedFormatSpecImpl format(c.format);
EXPECT_EQ(c.expected, FormatPack(format, absl::MakeSpan(args)));
}
}
TEST_F(FormatConvertTest, Uint128) {
absl::uint128 v = static_cast<absl::uint128>(0x1234567890abcdef) * 1979;
absl::uint128 max = absl::Uint128Max();
const FormatArgImpl args[] = {FormatArgImpl(v), FormatArgImpl(max)};
struct Case {
const char* format;
const char* expected;
} cases[] = {
{"%1$d", "2595989796776606496405"},
{"%1$30d", " 2595989796776606496405"},
{"%1$-30d", "2595989796776606496405 "},
{"%1$u", "2595989796776606496405"},
{"%1$x", "8cba9876066020f695"},
{"%2$d", "340282366920938463463374607431768211455"},
{"%2$u", "340282366920938463463374607431768211455"},
{"%2$x", "ffffffffffffffffffffffffffffffff"},
};
for (auto c : cases) {
UntypedFormatSpecImpl format(c.format);
EXPECT_EQ(c.expected, FormatPack(format, absl::MakeSpan(args)));
}
}
template <typename Floating>
void TestWithMultipleFormatsHelper(const std::vector<Floating> &floats) {
// Reserve the space to ensure we don't allocate memory in the output itself.
std::string str_format_result;
str_format_result.reserve(1 << 20);
std::string string_printf_result;
string_printf_result.reserve(1 << 20);
const char *const kFormats[] = {
"%", "%.3", "%8.5", "%500", "%.5000", "%.60", "%.30", "%03",
"%+", "% ", "%-10", "%#15.3", "%#.0", "%.0", "%1$*2$", "%1$.*2$"};
for (const char *fmt : kFormats) {
for (char f : {'f', 'F', //
'g', 'G', //
'a', 'A', //
'e', 'E'}) {
std::string fmt_str = std::string(fmt) + f;
if (fmt == absl::string_view("%.5000") && f != 'f' && f != 'F') {
// This particular test takes way too long with snprintf.
// Disable for the case we are not implementing natively.
continue;
}
for (Floating d : floats) {
int i = -10;
FormatArgImpl args[2] = {FormatArgImpl(d), FormatArgImpl(i)};
UntypedFormatSpecImpl format(fmt_str);
string_printf_result.clear();
StrAppend(&string_printf_result, fmt_str.c_str(), d, i);
str_format_result.clear();
{
AppendPack(&str_format_result, format, absl::MakeSpan(args));
}
if (string_printf_result != str_format_result) {
// We use ASSERT_EQ here because failures are usually correlated and a
// bug would print way too many failed expectations causing the test
// to time out.
ASSERT_EQ(string_printf_result, str_format_result)
<< fmt_str << " " << StrPrint("%.18g", d) << " "
<< StrPrint("%a", d) << " " << StrPrint("%.50f", d);
}
}
}
}
}
TEST_F(FormatConvertTest, Float) {
#ifdef _MSC_VER
// MSVC has a different rounding policy than us so we can't test our
// implementation against the native one there.
return;
#endif // _MSC_VER
std::vector<float> floats = {0.0f,
-0.0f,
.9999999f,
9999999.f,
std::numeric_limits<float>::max(),
-std::numeric_limits<float>::max(),
std::numeric_limits<float>::min(),
-std::numeric_limits<float>::min(),
std::numeric_limits<float>::lowest(),
-std::numeric_limits<float>::lowest(),
std::numeric_limits<float>::epsilon(),
std::numeric_limits<float>::epsilon() + 1.0f,
std::numeric_limits<float>::infinity(),
-std::numeric_limits<float>::infinity()};
// Some regression tests.
floats.push_back(0.999999989f);
if (std::numeric_limits<float>::has_denorm != std::denorm_absent) {
floats.push_back(std::numeric_limits<float>::denorm_min());
floats.push_back(-std::numeric_limits<float>::denorm_min());
}
for (float base :
{1.f, 12.f, 123.f, 1234.f, 12345.f, 123456.f, 1234567.f, 12345678.f,
123456789.f, 1234567890.f, 12345678901.f, 12345678.f, 12345678.f}) {
for (int exp = -123; exp <= 123; ++exp) {
for (int sign : {1, -1}) {
floats.push_back(sign * std::ldexp(base, exp));
}
}
}
for (int exp = -300; exp <= 300; ++exp) {
const float all_ones_mantissa = 0xffffff;
floats.push_back(std::ldexp(all_ones_mantissa, exp));
}
// Remove duplicates to speed up the logic below.
std::sort(floats.begin(), floats.end());
floats.erase(std::unique(floats.begin(), floats.end()), floats.end());
#ifndef __APPLE__
// Apple formats NaN differently (+nan) vs. (nan)
floats.push_back(std::nan(""));
#endif
TestWithMultipleFormatsHelper(floats);
}
TEST_F(FormatConvertTest, Double) {
#ifdef _MSC_VER
// MSVC has a different rounding policy than us so we can't test our
// implementation against the native one there.
return;
#endif // _MSC_VER
std::vector<double> doubles = {0.0,
-0.0,
.99999999999999,
99999999999999.,
std::numeric_limits<double>::max(),
-std::numeric_limits<double>::max(),
std::numeric_limits<double>::min(),
-std::numeric_limits<double>::min(),
std::numeric_limits<double>::lowest(),
-std::numeric_limits<double>::lowest(),
std::numeric_limits<double>::epsilon(),
std::numeric_limits<double>::epsilon() + 1,
std::numeric_limits<double>::infinity(),
-std::numeric_limits<double>::infinity()};
// Some regression tests.
doubles.push_back(0.99999999999999989);
if (std::numeric_limits<double>::has_denorm != std::denorm_absent) {
doubles.push_back(std::numeric_limits<double>::denorm_min());
doubles.push_back(-std::numeric_limits<double>::denorm_min());
}
for (double base :
{1., 12., 123., 1234., 12345., 123456., 1234567., 12345678., 123456789.,
1234567890., 12345678901., 123456789012., 1234567890123.}) {
for (int exp = -123; exp <= 123; ++exp) {
for (int sign : {1, -1}) {
doubles.push_back(sign * std::ldexp(base, exp));
}
}
}
// Workaround libc bug.
// https://sourceware.org/bugzilla/show_bug.cgi?id=22142
const bool gcc_bug_22142 =
StrPrint("%f", std::numeric_limits<double>::max()) !=
"1797693134862315708145274237317043567980705675258449965989174768031"
"5726078002853876058955863276687817154045895351438246423432132688946"
"4182768467546703537516986049910576551282076245490090389328944075868"
"5084551339423045832369032229481658085593321233482747978262041447231"
"68738177180919299881250404026184124858368.000000";
if (!gcc_bug_22142) {
for (int exp = -300; exp <= 300; ++exp) {
const double all_ones_mantissa = 0x1fffffffffffff;
doubles.push_back(std::ldexp(all_ones_mantissa, exp));
}
}
if (gcc_bug_22142) {
for (auto &d : doubles) {
using L = std::numeric_limits<double>;
double d2 = std::abs(d);
if (d2 == L::max() || d2 == L::min() || d2 == L::denorm_min()) {
d = 0;
}
}
}
// Remove duplicates to speed up the logic below.
std::sort(doubles.begin(), doubles.end());
doubles.erase(std::unique(doubles.begin(), doubles.end()), doubles.end());
#ifndef __APPLE__
// Apple formats NaN differently (+nan) vs. (nan)
doubles.push_back(std::nan(""));
#endif
TestWithMultipleFormatsHelper(doubles);
}
TEST_F(FormatConvertTest, DoubleRound) {
std::string s;
const auto format = [&](const char *fmt, double d) -> std::string & {
s.clear();
FormatArgImpl args[1] = {FormatArgImpl(d)};
AppendPack(&s, UntypedFormatSpecImpl(fmt), absl::MakeSpan(args));
#if !defined(_MSC_VER)
// MSVC has a different rounding policy than us so we can't test our
// implementation against the native one there.
EXPECT_EQ(StrPrint(fmt, d), s);
#endif // _MSC_VER
return s;
};
// All of these values have to be exactly represented.
// Otherwise we might not be testing what we think we are testing.
// These values can fit in a 64bit "fast" representation.
const double exact_value = 0.00000000000005684341886080801486968994140625;
assert(exact_value == std::pow(2, -44));
// Round up at a 5xx.
EXPECT_EQ(format("%.13f", exact_value), "0.0000000000001");
// Round up at a >5
EXPECT_EQ(format("%.14f", exact_value), "0.00000000000006");
// Round down at a <5
EXPECT_EQ(format("%.16f", exact_value), "0.0000000000000568");
// Nine handling
EXPECT_EQ(format("%.35f", exact_value),
"0.00000000000005684341886080801486969");
EXPECT_EQ(format("%.36f", exact_value),
"0.000000000000056843418860808014869690");
// Round down the last nine.
EXPECT_EQ(format("%.37f", exact_value),
"0.0000000000000568434188608080148696899");
EXPECT_EQ(format("%.10f", 0.000003814697265625), "0.0000038147");
// Round up the last nine
EXPECT_EQ(format("%.11f", 0.000003814697265625), "0.00000381470");
EXPECT_EQ(format("%.12f", 0.000003814697265625), "0.000003814697");
// Round to even (down)
EXPECT_EQ(format("%.43f", exact_value),
"0.0000000000000568434188608080148696899414062");
// Exact
EXPECT_EQ(format("%.44f", exact_value),
"0.00000000000005684341886080801486968994140625");
// Round to even (up), let make the last digits 75 instead of 25
EXPECT_EQ(format("%.43f", exact_value + std::pow(2, -43)),
"0.0000000000001705302565824240446090698242188");
// Exact, just to check.
EXPECT_EQ(format("%.44f", exact_value + std::pow(2, -43)),
"0.00000000000017053025658242404460906982421875");
// This value has to be small enough that it won't fit in the uint128
// representation for printing.
const double small_exact_value =
0.000000000000000000000000000000000000752316384526264005099991383822237233803945956334136013765601092018187046051025390625; // NOLINT
assert(small_exact_value == std::pow(2, -120));
// Round up at a 5xx.
EXPECT_EQ(format("%.37f", small_exact_value),
"0.0000000000000000000000000000000000008");
// Round down at a <5
EXPECT_EQ(format("%.38f", small_exact_value),
"0.00000000000000000000000000000000000075");
// Round up at a >5
EXPECT_EQ(format("%.41f", small_exact_value),
"0.00000000000000000000000000000000000075232");
// Nine handling
EXPECT_EQ(format("%.55f", small_exact_value),
"0.0000000000000000000000000000000000007523163845262640051");
EXPECT_EQ(format("%.56f", small_exact_value),
"0.00000000000000000000000000000000000075231638452626400510");
EXPECT_EQ(format("%.57f", small_exact_value),
"0.000000000000000000000000000000000000752316384526264005100");
EXPECT_EQ(format("%.58f", small_exact_value),
"0.0000000000000000000000000000000000007523163845262640051000");
// Round down the last nine
EXPECT_EQ(format("%.59f", small_exact_value),
"0.00000000000000000000000000000000000075231638452626400509999");
// Round up the last nine
EXPECT_EQ(format("%.79f", small_exact_value),
"0.000000000000000000000000000000000000"
"7523163845262640050999913838222372338039460");
// Round to even (down)
EXPECT_EQ(format("%.119f", small_exact_value),
"0.000000000000000000000000000000000000"
"75231638452626400509999138382223723380"
"394595633413601376560109201818704605102539062");
// Exact
EXPECT_EQ(format("%.120f", small_exact_value),
"0.000000000000000000000000000000000000"
"75231638452626400509999138382223723380"
"3945956334136013765601092018187046051025390625");
// Round to even (up), let make the last digits 75 instead of 25
EXPECT_EQ(format("%.119f", small_exact_value + std::pow(2, -119)),
"0.000000000000000000000000000000000002"
"25694915357879201529997415146671170141"
"183786900240804129680327605456113815307617188");
// Exact, just to check.
EXPECT_EQ(format("%.120f", small_exact_value + std::pow(2, -119)),
"0.000000000000000000000000000000000002"
"25694915357879201529997415146671170141"
"1837869002408041296803276054561138153076171875");
}
// We don't actually store the results. This is just to exercise the rest of the
// machinery.
struct NullSink {
friend void AbslFormatFlush(NullSink *sink, string_view str) {}
};
template <typename... T>
bool FormatWithNullSink(absl::string_view fmt, const T &... a) {
NullSink sink;
FormatArgImpl args[] = {FormatArgImpl(a)...};
return FormatUntyped(&sink, UntypedFormatSpecImpl(fmt), absl::MakeSpan(args));
}
TEST_F(FormatConvertTest, ExtremeWidthPrecision) {
for (const char *fmt : {"f"}) {
for (double d : {1e-100, 1.0, 1e100}) {
constexpr int max = std::numeric_limits<int>::max();
EXPECT_TRUE(FormatWithNullSink(std::string("%.*") + fmt, max, d));
EXPECT_TRUE(FormatWithNullSink(std::string("%1.*") + fmt, max, d));
EXPECT_TRUE(FormatWithNullSink(std::string("%*") + fmt, max, d));
EXPECT_TRUE(FormatWithNullSink(std::string("%*.*") + fmt, max, max, d));
}
}
}
TEST_F(FormatConvertTest, LongDouble) {
#ifdef _MSC_VER
// MSVC has a different rounding policy than us so we can't test our
// implementation against the native one there.
return;
#endif // _MSC_VER
const char *const kFormats[] = {"%", "%.3", "%8.5", "%9", "%.5000",
"%.60", "%+", "% ", "%-10"};
std::vector<long double> doubles = {
0.0,
-0.0,
std::numeric_limits<long double>::max(),
-std::numeric_limits<long double>::max(),
std::numeric_limits<long double>::min(),
-std::numeric_limits<long double>::min(),
std::numeric_limits<long double>::infinity(),
-std::numeric_limits<long double>::infinity()};
for (long double base : {1.L, 12.L, 123.L, 1234.L, 12345.L, 123456.L,
1234567.L, 12345678.L, 123456789.L, 1234567890.L,
12345678901.L, 123456789012.L, 1234567890123.L,
// This value is not representable in double, but it
// is in long double that uses the extended format.
// This is to verify that we are not truncating the
// value mistakenly through a double.
10000000000000000.25L}) {
for (int exp : {-1000, -500, 0, 500, 1000}) {
for (int sign : {1, -1}) {
doubles.push_back(sign * std::ldexp(base, exp));
doubles.push_back(sign / std::ldexp(base, exp));
}
}
}
// Regression tests
//
// Using a string literal because not all platforms support hex literals or it
// might be out of range.
doubles.push_back(std::strtold("-0xf.ffffffb5feafffbp-16324L", nullptr));
for (const char *fmt : kFormats) {
for (char f : {'f', 'F', //
'g', 'G', //
'a', 'A', //
'e', 'E'}) {
std::string fmt_str = std::string(fmt) + 'L' + f;
if (fmt == absl::string_view("%.5000") && f != 'f' && f != 'F') {
// This particular test takes way too long with snprintf.
// Disable for the case we are not implementing natively.
continue;
}
for (auto d : doubles) {
FormatArgImpl arg(d);
UntypedFormatSpecImpl format(fmt_str);
// We use ASSERT_EQ here because failures are usually correlated and a
// bug would print way too many failed expectations causing the test to
// time out.
ASSERT_EQ(StrPrint(fmt_str.c_str(), d), FormatPack(format, {&arg, 1}))
<< fmt_str << " " << StrPrint("%.18Lg", d) << " "
<< StrPrint("%La", d) << " " << StrPrint("%.1080Lf", d);
}
}
}
}
TEST_F(FormatConvertTest, IntAsDouble) {
const int kMin = std::numeric_limits<int>::min();
const int kMax = std::numeric_limits<int>::max();
const int ia[] = {
1, 2, 3, 123,
-1, -2, -3, -123,
0, kMax - 1, kMax, kMin + 1, kMin };
for (const int fx : ia) {
SCOPED_TRACE(fx);
const FormatArgImpl args[] = {FormatArgImpl(fx)};
struct Expectation {
int line;
std::string out;
const char *fmt;
};
const double dx = static_cast<double>(fx);
const Expectation kExpect[] = {
{ __LINE__, StrPrint("%f", dx), "%f" },
{ __LINE__, StrPrint("%12f", dx), "%12f" },
{ __LINE__, StrPrint("%.12f", dx), "%.12f" },
{ __LINE__, StrPrint("%12a", dx), "%12a" },
{ __LINE__, StrPrint("%.12a", dx), "%.12a" },
};
for (const Expectation &e : kExpect) {
SCOPED_TRACE(e.line);
SCOPED_TRACE(e.fmt);
UntypedFormatSpecImpl format(e.fmt);
EXPECT_EQ(e.out, FormatPack(format, absl::MakeSpan(args)));
}
}
}
template <typename T>
bool FormatFails(const char* test_format, T value) {
std::string format_string = std::string("<<") + test_format + ">>";
UntypedFormatSpecImpl format(format_string);
int one = 1;
const FormatArgImpl args[] = {FormatArgImpl(value), FormatArgImpl(one)};
EXPECT_EQ(FormatPack(format, absl::MakeSpan(args)), "")
<< "format=" << test_format << " value=" << value;
return FormatPack(format, absl::MakeSpan(args)).empty();
}
TEST_F(FormatConvertTest, ExpectedFailures) {
// Int input
EXPECT_TRUE(FormatFails("%p", 1));
EXPECT_TRUE(FormatFails("%s", 1));
EXPECT_TRUE(FormatFails("%n", 1));
// Double input
EXPECT_TRUE(FormatFails("%p", 1.));
EXPECT_TRUE(FormatFails("%s", 1.));
EXPECT_TRUE(FormatFails("%n", 1.));
EXPECT_TRUE(FormatFails("%c", 1.));
EXPECT_TRUE(FormatFails("%d", 1.));
EXPECT_TRUE(FormatFails("%x", 1.));
EXPECT_TRUE(FormatFails("%*d", 1.));
// String input
EXPECT_TRUE(FormatFails("%n", ""));
EXPECT_TRUE(FormatFails("%c", ""));
EXPECT_TRUE(FormatFails("%d", ""));
EXPECT_TRUE(FormatFails("%x", ""));
EXPECT_TRUE(FormatFails("%f", ""));
EXPECT_TRUE(FormatFails("%*d", ""));
}
} // namespace
} // namespace str_format_internal
ABSL_NAMESPACE_END
} // namespace absl