Google Git
Sign in
flutter / third_party / abseil-cpp / 1db3bdd4eb208bef55c77f22aa94991e52225230 / . / absl / strings / internal / str_format / convert_test.cc
blob: 7f2227787717f86b63475e060199bdacc1d5cee3 [file] [log] [blame]
// Copyright 2020 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include <assert.h>
#include <locale.h>
#include <stdarg.h>
#include <stdio.h>
#include <algorithm>
#include <climits>
#include <cmath>
#include <cstdlib>
#include <cstring>
#include <cwctype>
#include <limits>
#include <set>
#include <sstream>
#include <string>
#include <thread> // NOLINT
#include <type_traits>
#include <vector>
#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "absl/base/attributes.h"
#include "absl/base/internal/raw_logging.h"
#include "absl/log/log.h"
#include "absl/numeric/int128.h"
#include "absl/strings/ascii.h"
#include "absl/strings/internal/str_format/arg.h"
#include "absl/strings/internal/str_format/bind.h"
#include "absl/strings/match.h"
#include "absl/strings/str_format.h"
#include "absl/strings/string_view.h"
#include "absl/types/optional.h"
#include "absl/types/span.h"
#if defined(ABSL_HAVE_STD_STRING_VIEW)
#include <string_view>
#endif
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace str_format_internal {
namespace {
struct NativePrintfTraits {
bool hex_float_has_glibc_rounding;
bool hex_float_prefers_denormal_repr;
bool hex_float_uses_minimal_precision_when_not_specified;
bool hex_float_optimizes_leading_digit_bit_count;
};
template <typename T, size_t N>
size_t ArraySize(T (&)[N]) {
return N;
}
template <typename T>
struct AlwaysFalse : std::false_type {};
template <typename T>
std::string LengthModFor() {
static_assert(AlwaysFalse<T>::value, "Unsupported type");
return "";
}
template <>
std::string LengthModFor<char>() {
return "hh";
}
template <>
std::string LengthModFor<signed char>() {
return "hh";
}
template <>
std::string LengthModFor<unsigned char>() {
return "hh";
}
template <>
std::string LengthModFor<short>() { // NOLINT
return "h";
}
template <>
std::string LengthModFor<unsigned short>() { // NOLINT
return "h";
}
template <>
std::string LengthModFor<int>() {
return "";
}
template <>
std::string LengthModFor<unsigned>() {
return "";
}
template <>
std::string LengthModFor<long>() { // NOLINT
return "l";
}
template <>
std::string LengthModFor<unsigned long>() { // NOLINT
return "l";
}
template <>
std::string LengthModFor<long long>() { // NOLINT
return "ll";
}
template <>
std::string LengthModFor<unsigned long long>() { // NOLINT
return "ll";
}
// An integral type of the same rank and signedness as `wchar_t`, that isn't
// `wchar_t`.
using IntegralTypeForWCharT =
std::conditional_t<std::is_signed<wchar_t>::value,
// Some STLs are broken and return `wchar_t` from
// `std::make_[un]signed_t<wchar_t>` when the signedness
// matches. Work around by round-tripping through the
// opposite signedness.
std::make_signed_t<std::make_unsigned_t<wchar_t>>,
std::make_unsigned_t<std::make_signed_t<wchar_t>>>;
// Given an integral type `T`, returns a type of the same rank and signedness
// that is guaranteed to not be `wchar_t`.
template <typename T>
using MatchingIntegralType = std::conditional_t<std::is_same<T, wchar_t>::value,
IntegralTypeForWCharT, T>;
std::string EscCharImpl(int v) {
char buf[64];
int n = absl::ascii_isprint(static_cast<unsigned char>(v))
? snprintf(buf, sizeof(buf), "'%c'", v)
: snprintf(buf, sizeof(buf), "'\\x%.*x'", CHAR_BIT / 4,
static_cast<unsigned>(
static_cast<std::make_unsigned_t<char>>(v)));
assert(n > 0 && static_cast<size_t>(n) < sizeof(buf));
return std::string(buf, static_cast<size_t>(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); }
std::string Esc(wchar_t v) {
char buf[64];
int n = std::iswprint(static_cast<wint_t>(v))
? snprintf(buf, sizeof(buf), "L'%lc'", static_cast<wint_t>(v))
: snprintf(buf, sizeof(buf), "L'\\x%.*llx'",
static_cast<int>(sizeof(wchar_t) * CHAR_BIT / 4),
static_cast<unsigned long long>(
static_cast<std::make_unsigned_t<wchar_t>>(v)));
assert(n > 0 && static_cast<size_t>(n) < sizeof(buf));
return std::string(buf, static_cast<size_t>(n));
}
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, static_cast<size_t>(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.
size_t length = static_cast<size_t>(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 && static_cast<size_t>(result) < length) {
// It fit
dst->append(buf, static_cast<size_t>(result));
}
delete[] buf;
}
void StrAppend(std::string *, const char *, ...) ABSL_PRINTF_ATTRIBUTE(2, 3);
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 *, ...) ABSL_PRINTF_ATTRIBUTE(1, 2);
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;
}
NativePrintfTraits VerifyNativeImplementationImpl() {
NativePrintfTraits result;
// >>> hex_float_has_glibc_rounding. To have glibc's rounding behavior we need
// to meet three requirements:
//
// - The threshold for rounding up is 8 (for e.g. MSVC uses 9).
// - If the digits lower than than the 8 are non-zero then we round up.
// - If the digits lower than the 8 are all zero then we round toward even.
//
// The numbers below represent all the cases covering {below,at,above} the
// threshold (8) with both {zero,non-zero} lower bits and both {even,odd}
// preceding digits.
const double d0079 = 65657.0; // 0x1.0079p+16
const double d0179 = 65913.0; // 0x1.0179p+16
const double d0080 = 65664.0; // 0x1.0080p+16
const double d0180 = 65920.0; // 0x1.0180p+16
const double d0081 = 65665.0; // 0x1.0081p+16
const double d0181 = 65921.0; // 0x1.0181p+16
result.hex_float_has_glibc_rounding =
StartsWith(StrPrint("%.2a", d0079), "0x1.00") &&
StartsWith(StrPrint("%.2a", d0179), "0x1.01") &&
StartsWith(StrPrint("%.2a", d0080), "0x1.00") &&
StartsWith(StrPrint("%.2a", d0180), "0x1.02") &&
StartsWith(StrPrint("%.2a", d0081), "0x1.01") &&
StartsWith(StrPrint("%.2a", d0181), "0x1.02");
// >>> hex_float_prefers_denormal_repr. Formatting `denormal` on glibc yields
// "0x0.0000000000001p-1022", whereas on std libs that don't use denormal
// representation it would either be 0x1p-1074 or 0x1.0000000000000-1074.
const double denormal = std::numeric_limits<double>::denorm_min();
result.hex_float_prefers_denormal_repr =
StartsWith(StrPrint("%a", denormal), "0x0.0000000000001");
// >>> hex_float_uses_minimal_precision_when_not_specified. Some (non-glibc)
// libs will format the following as "0x1.0079000000000p+16".
result.hex_float_uses_minimal_precision_when_not_specified =
(StrPrint("%a", d0079) == "0x1.0079p+16");
// >>> hex_float_optimizes_leading_digit_bit_count. The number 1.5, when
// formatted by glibc should yield "0x1.8p+0" for `double` and "0xcp-3" for
// `long double`, i.e., number of bits in the leading digit is adapted to the
// number of bits in the mantissa.
const double d_15 = 1.5;
const long double ld_15 = 1.5;
result.hex_float_optimizes_leading_digit_bit_count =
StartsWith(StrPrint("%a", d_15), "0x1.8") &&
StartsWith(StrPrint("%La", ld_15), "0xc");
return result;
}
const NativePrintfTraits &VerifyNativeImplementation() {
static NativePrintfTraits native_traits = VerifyNativeImplementationImpl();
return native_traits;
}
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(L"hello");
TestStringConvert(static_cast<const char*>("hello"));
TestStringConvert(static_cast<const wchar_t*>(L"hello"));
TestStringConvert(std::string("hello"));
TestStringConvert(std::wstring(L"hello"));
TestStringConvert(string_view("hello"));
#if defined(ABSL_HAVE_STD_STRING_VIEW)
TestStringConvert(std::string_view("hello"));
TestStringConvert(std::wstring_view(L"hello"));
#endif // ABSL_HAVE_STD_STRING_VIEW
}
TEST_F(FormatConvertTest, NullString) {
const char* p = nullptr;
UntypedFormatSpecImpl format("%s");
EXPECT_EQ("", FormatPack(format, {FormatArgImpl(p)}));
const wchar_t* wp = nullptr;
UntypedFormatSpecImpl wformat("%ls");
EXPECT_EQ("", FormatPack(wformat, {FormatArgImpl(wp)}));
}
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)}));
wchar_t wc = L'a';
const wchar_t* wp = &wc;
UntypedFormatSpecImpl wformat("%.1ls");
EXPECT_EQ("a", FormatPack(wformat, {FormatArgImpl(wp)}));
// We cap at the NUL-terminator.
p = "ABC";
UntypedFormatSpecImpl format2("%.10s");
EXPECT_EQ("ABC", FormatPack(format2, {FormatArgImpl(p)}));
wp = L"ABC";
UntypedFormatSpecImpl wformat2("%.10ls");
EXPECT_EQ("ABC", FormatPack(wformat2, {FormatArgImpl(wp)}));
}
// 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) {
LOG(FATAL) << "Could not parse " << arg;
}
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;
wchar_t wc = L'h';
wchar_t *mwcp = &wc;
const wchar_t *wcp = L"hi";
const wchar_t *wcnil = nullptr;
const int *inil = nullptr;
using VoidF = void (*)();
VoidF fp = [] {}, fnil = nullptr;
volatile char vc;
volatile char *vcp = &vc;
volatile char *vcnil = nullptr;
volatile wchar_t vwc;
volatile wchar_t *vwcp = &vwc;
volatile wchar_t *vwcnil = nullptr;
const FormatArgImpl args_array[] = {
FormatArgImpl(xp), FormatArgImpl(cp), FormatArgImpl(wcp),
FormatArgImpl(inil), FormatArgImpl(cnil), FormatArgImpl(wcnil),
FormatArgImpl(mcp), FormatArgImpl(mwcp), FormatArgImpl(fp),
FormatArgImpl(fnil), FormatArgImpl(vcp), FormatArgImpl(vwcp),
FormatArgImpl(vcnil), FormatArgImpl(vwcnil),
};
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 int*
EXPECT_THAT(FormatPack(UntypedFormatSpecImpl("%1$p"), args),
MatchesPointerString(xp));
// const char*
EXPECT_THAT(FormatPack(UntypedFormatSpecImpl("%2$p"), args),
MatchesPointerString(cp));
// const wchar_t*
EXPECT_THAT(FormatPack(UntypedFormatSpecImpl("%3$p"), args),
MatchesPointerString(wcp));
// null const int*
EXPECT_THAT(FormatPack(UntypedFormatSpecImpl("%4$p"), args),
MatchesPointerString(nullptr));
// null const char*
EXPECT_THAT(FormatPack(UntypedFormatSpecImpl("%5$p"), args),
MatchesPointerString(nullptr));
// null const wchar_t*
EXPECT_THAT(FormatPack(UntypedFormatSpecImpl("%6$p"), args),
MatchesPointerString(nullptr));
// nonconst char*
EXPECT_THAT(FormatPack(UntypedFormatSpecImpl("%7$p"), args),
MatchesPointerString(mcp));
// nonconst wchar_t*
EXPECT_THAT(FormatPack(UntypedFormatSpecImpl("%8$p"), args),
MatchesPointerString(mwcp));
// function pointer
EXPECT_THAT(FormatPack(UntypedFormatSpecImpl("%9$p"), args),
MatchesPointerString(reinterpret_cast<const void *>(fp)));
// null function pointer
EXPECT_THAT(FormatPack(UntypedFormatSpecImpl("%10$p"), args),
MatchesPointerString(nullptr));
// volatile char*
EXPECT_THAT(
FormatPack(UntypedFormatSpecImpl("%11$p"), args),
MatchesPointerString(reinterpret_cast<volatile const void *>(vcp)));
// volatile wchar_t*
EXPECT_THAT(
FormatPack(UntypedFormatSpecImpl("%12$p"), args),
MatchesPointerString(reinterpret_cast<volatile const void *>(vwcp)));
// null volatile char*
EXPECT_THAT(FormatPack(UntypedFormatSpecImpl("%13$p"), args),
MatchesPointerString(nullptr));
// null volatile wchar_t*
EXPECT_THAT(FormatPack(UntypedFormatSpecImpl("%14$p"), args),
MatchesPointerString(nullptr));
}
struct Cardinal {
enum Pos { k1 = 1, k2 = 2, k3 = 3 };
enum Neg { kM1 = -1, kM2 = -2, kM3 = -3 };
};
TEST_F(FormatConvertTest, Enum) {
const Cardinal::Pos k3 = Cardinal::k3;
const Cardinal::Neg km3 = Cardinal::kM3;
const FormatArgImpl args[] = {FormatArgImpl(k3), FormatArgImpl(km3)};
UntypedFormatSpecImpl format("%1$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 =
static_cast<std::remove_volatile_t<UnsignedT>>(val);
old_fmt += LengthModFor<
MatchingIntegralType<std::remove_cv_t<decltype(uval)>>>();
old_fmt += "u";
old_result = StrPrint(old_fmt.c_str(), uval);
} else {
old_fmt += LengthModFor<
MatchingIntegralType<std::remove_cv_t<decltype(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)));
}
}
}
}
}
}
template <typename T>
absl::optional<std::string> StrPrintChar(T c) {
return StrPrint("%c", static_cast<int>(c));
}
template <>
absl::optional<std::string> StrPrintChar(wchar_t c) {
// musl libc has a bug where ("%lc", 0) writes no characters, and Android
// doesn't support forcing UTF-8 via setlocale(). Hardcode the expected
// answers for ASCII inputs to maximize test coverage on these platforms.
if (static_cast<std::make_unsigned_t<wchar_t>>(c) < 0x80) {
return std::string(1, static_cast<char>(c));
}
// Force a UTF-8 locale to match the expected `StrFormat()` behavior.
// It's important to copy the string returned by `old_locale` here, because
// its contents are not guaranteed to be valid after the next `setlocale()`
// call.
std::string old_locale = setlocale(LC_CTYPE, nullptr);
if (!setlocale(LC_CTYPE, "en_US.UTF-8")) {
return absl::nullopt;
}
const std::string output = StrPrint("%lc", static_cast<wint_t>(c));
setlocale(LC_CTYPE, old_locale.c_str());
return output;
}
template <typename T>
typename std::remove_volatile<T>::type GetMaxForConversion() {
return static_cast<typename std::remove_volatile<T>::type>(
std::numeric_limits<int>::max());
}
template <>
wchar_t GetMaxForConversion<wchar_t>() {
// Don't return values that aren't legal Unicode. For wchar_t conversions in a
// UTF-8 locale, conversion behavior for such values is unspecified, and we
// don't care about matching it.
return (sizeof(wchar_t) * CHAR_BIT <= 16) ? wchar_t{0xffff}
: static_cast<wchar_t>(0x10ffff);
}
TYPED_TEST_P(TypedFormatConvertTest, Char) {
// Pass a bunch of values of type TypeParam to both FormatPack and libc's
// vsnprintf("%c", ...) (wrapped in StrPrint) to make sure we get the same
// value.
typedef TypeParam T;
using remove_volatile_t = typename std::remove_volatile<T>::type;
std::vector<remove_volatile_t> vals = {
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),
};
// We'd like to test values near std::numeric_limits::min() and
// std::numeric_limits::max(), too, but vsnprintf("%c", ...) can't handle
// anything larger than an int. Add in the most extreme values we can without
// exceeding that range.
// Special case: Formatting a wchar_t should behave like vsnprintf("%lc").
// Technically vsnprintf can accept a wint_t in this case, but since we must
// pass a wchar_t to FormatPack, the largest type we can use here is wchar_t.
using ArgType =
std::conditional_t<std::is_same<T, wchar_t>::value, wchar_t, int>;
static const T kMin =
static_cast<remove_volatile_t>(std::numeric_limits<ArgType>::min());
static const T kMax = GetMaxForConversion<T>();
vals.insert(vals.end(), {static_cast<remove_volatile_t>(kMin + 1), kMin,
static_cast<remove_volatile_t>(kMax - 1), kMax});
static const auto kMaxWCharT =
static_cast<remove_volatile_t>(GetMaxForConversion<wchar_t>());
for (const T c : vals) {
SCOPED_TRACE(Esc(c));
const FormatArgImpl args[] = {FormatArgImpl(c)};
UntypedFormatSpecImpl format("%c");
absl::optional<std::string> result = StrPrintChar(c);
if (result.has_value()) {
EXPECT_EQ(result.value(), FormatPack(format, absl::MakeSpan(args)));
}
// Also test that if the format specifier is "%lc", the argument is treated
// as if it's a `wchar_t`.
const T wc =
std::max(remove_volatile_t{0},
std::min(static_cast<remove_volatile_t>(c), kMaxWCharT));
SCOPED_TRACE(Esc(wc));
const FormatArgImpl wide_args[] = {FormatArgImpl(wc)};
UntypedFormatSpecImpl wide_format("%lc");
result = StrPrintChar(static_cast<wchar_t>(wc));
if (result.has_value()) {
EXPECT_EQ(result.value(),
FormatPack(wide_format, absl::MakeSpan(wide_args)));
}
}
}
REGISTER_TYPED_TEST_SUITE_P(TypedFormatConvertTest, AllIntsWithFlags, Char);
typedef ::testing::Types<int, unsigned, volatile int, short, // NOLINT
unsigned short, long, unsigned long, // NOLINT
long long, unsigned long long, // NOLINT
signed char, unsigned char, char, wchar_t>
AllIntTypes;
INSTANTIATE_TYPED_TEST_SUITE_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, UnicodeWideString) {
// StrFormat() should be able to convert wide strings containing Unicode
// characters (to UTF-8).
const FormatArgImpl args[] = {FormatArgImpl(L"\u47e3 \U00011112")};
// `u8""` forces UTF-8 encoding; MSVC will default to e.g. CP1252 (and warn)
// without it. However, the resulting character type differs between pre-C++20
// (`char`) and C++20 (`char8_t`). So deduce the right character type for all
// C++ versions, init it with UTF-8, then `memcpy()` to get the result as a
// `char*`.
using ConstChar8T = std::remove_reference_t<decltype(*u8"a")>;
ConstChar8T kOutputUtf8[] = u8"\u47e3 \U00011112";
char output[sizeof kOutputUtf8];
std::memcpy(output, kOutputUtf8, sizeof kOutputUtf8);
EXPECT_EQ(output,
FormatPack(UntypedFormatSpecImpl("%ls"), absl::MakeSpan(args)));
}
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$x", "ffffffffffffffffffffffffffffffff"},
};
for (auto c : cases) {
UntypedFormatSpecImpl format(c.format);
EXPECT_EQ(c.expected, FormatPack(format, absl::MakeSpan(args)));
}
}
template <typename Floating>
void TestWithMultipleFormatsHelper(const std::vector<Floating> &floats,
const std::set<Floating> &skip_verify) {
const NativePrintfTraits &native_traits = VerifyNativeImplementation();
// Reserve the space to ensure we don't allocate memory in the output itself.
std::string str_format_result;
str_format_result.reserve(1 << 20);
std::string string_printf_result;
string_printf_result.reserve(1 << 20);
const char *const kFormats[] = {
"%", "%.3", "%8.5", "%500", "%.5000", "%.60", "%.30", "%03",
"%+", "% ", "%-10", "%#15.3", "%#.0", "%.0", "%1$*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' &&
f != 'a' && f != 'A') {
// This particular test takes way too long with snprintf.
// Disable for the case we are not implementing natively.
continue;
}
if ((f == 'a' || f == 'A') &&
!native_traits.hex_float_has_glibc_rounding) {
continue;
}
for (Floating d : floats) {
if (!native_traits.hex_float_prefers_denormal_repr &&
(f == 'a' || f == 'A') && std::fpclassify(d) == FP_SUBNORMAL) {
continue;
}
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));
}
#ifdef _MSC_VER
// MSVC has a different rounding policy than us so we can't test our
// implementation against the native one there.
continue;
#elif defined(__APPLE__)
// Apple formats NaN differently (+nan) vs. (nan)
if (std::isnan(d)) continue;
#endif
if (string_printf_result != str_format_result &&
skip_verify.find(d) == skip_verify.end()) {
// 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) {
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(),
std::nanf("")};
// 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(), [](const float a, const float b) {
if (std::isnan(a)) return false;
if (std::isnan(b)) return true;
return a < b;
});
floats.erase(std::unique(floats.begin(), floats.end()), floats.end());
TestWithMultipleFormatsHelper(floats, {});
}
TEST_F(FormatConvertTest, Double) {
// For values that we know won't match the standard library implementation we
// skip verification, but still run the algorithm to catch asserts/sanitizer
// bugs.
std::set<double> skip_verify;
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(),
std::nan("")};
// 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";
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) {
skip_verify.insert(doubles.back());
}
}
if (gcc_bug_22142) {
using L = std::numeric_limits<double>;
skip_verify.insert(L::max());
skip_verify.insert(L::min()); // NOLINT
skip_verify.insert(L::denorm_min());
skip_verify.insert(-L::max());
skip_verify.insert(-L::min()); // NOLINT
skip_verify.insert(-L::denorm_min());
}
// Remove duplicates to speed up the logic below.
std::sort(doubles.begin(), doubles.end(), [](const double a, const double b) {
if (std::isnan(a)) return false;
if (std::isnan(b)) return true;
return a < b;
});
doubles.erase(std::unique(doubles.begin(), doubles.end()), doubles.end());
TestWithMultipleFormatsHelper(doubles, skip_verify);
}
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");
}
TEST_F(FormatConvertTest, DoubleRoundA) {
const NativePrintfTraits &native_traits = VerifyNativeImplementation();
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 (native_traits.hex_float_has_glibc_rounding) {
EXPECT_EQ(StrPrint(fmt, d), s);
}
return s;
};
// 0x1.00018000p+100
const double on_boundary_odd = 1267679614447900152596896153600.0;
EXPECT_EQ(format("%.0a", on_boundary_odd), "0x1p+100");
EXPECT_EQ(format("%.1a", on_boundary_odd), "0x1.0p+100");
EXPECT_EQ(format("%.2a", on_boundary_odd), "0x1.00p+100");
EXPECT_EQ(format("%.3a", on_boundary_odd), "0x1.000p+100");
EXPECT_EQ(format("%.4a", on_boundary_odd), "0x1.0002p+100"); // round
EXPECT_EQ(format("%.5a", on_boundary_odd), "0x1.00018p+100");
EXPECT_EQ(format("%.6a", on_boundary_odd), "0x1.000180p+100");
// 0x1.00028000p-2
const double on_boundary_even = 0.250009536743164062500;
EXPECT_EQ(format("%.0a", on_boundary_even), "0x1p-2");
EXPECT_EQ(format("%.1a", on_boundary_even), "0x1.0p-2");
EXPECT_EQ(format("%.2a", on_boundary_even), "0x1.00p-2");
EXPECT_EQ(format("%.3a", on_boundary_even), "0x1.000p-2");
EXPECT_EQ(format("%.4a", on_boundary_even), "0x1.0002p-2"); // no round
EXPECT_EQ(format("%.5a", on_boundary_even), "0x1.00028p-2");
EXPECT_EQ(format("%.6a", on_boundary_even), "0x1.000280p-2");
// 0x1.00018001p+1
const double slightly_over = 2.00004577683284878730773925781250;
EXPECT_EQ(format("%.0a", slightly_over), "0x1p+1");
EXPECT_EQ(format("%.1a", slightly_over), "0x1.0p+1");
EXPECT_EQ(format("%.2a", slightly_over), "0x1.00p+1");
EXPECT_EQ(format("%.3a", slightly_over), "0x1.000p+1");
EXPECT_EQ(format("%.4a", slightly_over), "0x1.0002p+1");
EXPECT_EQ(format("%.5a", slightly_over), "0x1.00018p+1");
EXPECT_EQ(format("%.6a", slightly_over), "0x1.000180p+1");
// 0x1.00017fffp+0
const double slightly_under = 1.000022887950763106346130371093750;
EXPECT_EQ(format("%.0a", slightly_under), "0x1p+0");
EXPECT_EQ(format("%.1a", slightly_under), "0x1.0p+0");
EXPECT_EQ(format("%.2a", slightly_under), "0x1.00p+0");
EXPECT_EQ(format("%.3a", slightly_under), "0x1.000p+0");
EXPECT_EQ(format("%.4a", slightly_under), "0x1.0001p+0");
EXPECT_EQ(format("%.5a", slightly_under), "0x1.00018p+0");
EXPECT_EQ(format("%.6a", slightly_under), "0x1.000180p+0");
EXPECT_EQ(format("%.7a", slightly_under), "0x1.0001800p+0");
// 0x1.1b3829ac28058p+3
const double hex_value = 8.85060580848964661981881363317370414733886718750;
EXPECT_EQ(format("%.0a", hex_value), "0x1p+3");
EXPECT_EQ(format("%.1a", hex_value), "0x1.2p+3");
EXPECT_EQ(format("%.2a", hex_value), "0x1.1bp+3");
EXPECT_EQ(format("%.3a", hex_value), "0x1.1b4p+3");
EXPECT_EQ(format("%.4a", hex_value), "0x1.1b38p+3");
EXPECT_EQ(format("%.5a", hex_value), "0x1.1b383p+3");
EXPECT_EQ(format("%.6a", hex_value), "0x1.1b382ap+3");
EXPECT_EQ(format("%.7a", hex_value), "0x1.1b3829bp+3");
EXPECT_EQ(format("%.8a", hex_value), "0x1.1b3829acp+3");
EXPECT_EQ(format("%.9a", hex_value), "0x1.1b3829ac3p+3");
EXPECT_EQ(format("%.10a", hex_value), "0x1.1b3829ac28p+3");
EXPECT_EQ(format("%.11a", hex_value), "0x1.1b3829ac280p+3");
EXPECT_EQ(format("%.12a", hex_value), "0x1.1b3829ac2806p+3");
EXPECT_EQ(format("%.13a", hex_value), "0x1.1b3829ac28058p+3");
EXPECT_EQ(format("%.14a", hex_value), "0x1.1b3829ac280580p+3");
EXPECT_EQ(format("%.15a", hex_value), "0x1.1b3829ac2805800p+3");
EXPECT_EQ(format("%.16a", hex_value), "0x1.1b3829ac28058000p+3");
EXPECT_EQ(format("%.17a", hex_value), "0x1.1b3829ac280580000p+3");
EXPECT_EQ(format("%.18a", hex_value), "0x1.1b3829ac2805800000p+3");
EXPECT_EQ(format("%.19a", hex_value), "0x1.1b3829ac28058000000p+3");
EXPECT_EQ(format("%.20a", hex_value), "0x1.1b3829ac280580000000p+3");
EXPECT_EQ(format("%.21a", hex_value), "0x1.1b3829ac2805800000000p+3");
// 0x1.0818283848586p+3
const double hex_value2 = 8.2529488658208371987257123691961169242858886718750;
EXPECT_EQ(format("%.0a", hex_value2), "0x1p+3");
EXPECT_EQ(format("%.1a", hex_value2), "0x1.1p+3");
EXPECT_EQ(format("%.2a", hex_value2), "0x1.08p+3");
EXPECT_EQ(format("%.3a", hex_value2), "0x1.082p+3");
EXPECT_EQ(format("%.4a", hex_value2), "0x1.0818p+3");
EXPECT_EQ(format("%.5a", hex_value2), "0x1.08183p+3");
EXPECT_EQ(format("%.6a", hex_value2), "0x1.081828p+3");
EXPECT_EQ(format("%.7a", hex_value2), "0x1.0818284p+3");
EXPECT_EQ(format("%.8a", hex_value2), "0x1.08182838p+3");
EXPECT_EQ(format("%.9a", hex_value2), "0x1.081828385p+3");
EXPECT_EQ(format("%.10a", hex_value2), "0x1.0818283848p+3");
EXPECT_EQ(format("%.11a", hex_value2), "0x1.08182838486p+3");
EXPECT_EQ(format("%.12a", hex_value2), "0x1.081828384858p+3");
EXPECT_EQ(format("%.13a", hex_value2), "0x1.0818283848586p+3");
EXPECT_EQ(format("%.14a", hex_value2), "0x1.08182838485860p+3");
EXPECT_EQ(format("%.15a", hex_value2), "0x1.081828384858600p+3");
EXPECT_EQ(format("%.16a", hex_value2), "0x1.0818283848586000p+3");
EXPECT_EQ(format("%.17a", hex_value2), "0x1.08182838485860000p+3");
EXPECT_EQ(format("%.18a", hex_value2), "0x1.081828384858600000p+3");
EXPECT_EQ(format("%.19a", hex_value2), "0x1.0818283848586000000p+3");
EXPECT_EQ(format("%.20a", hex_value2), "0x1.08182838485860000000p+3");
EXPECT_EQ(format("%.21a", hex_value2), "0x1.081828384858600000000p+3");
}
TEST_F(FormatConvertTest, LongDoubleRoundA) {
if (std::numeric_limits<long double>::digits % 4 != 0) {
// This test doesn't really make sense to run on platforms where a long
// double has a different mantissa size (mod 4) than Prod, since then the
// leading digit will be formatted differently.
return;
}
const NativePrintfTraits &native_traits = VerifyNativeImplementation();
std::string s;
const auto format = [&](const char *fmt, long double d) -> std::string & {
s.clear();
FormatArgImpl args[1] = {FormatArgImpl(d)};
AppendPack(&s, UntypedFormatSpecImpl(fmt), absl::MakeSpan(args));
if (native_traits.hex_float_has_glibc_rounding &&
native_traits.hex_float_optimizes_leading_digit_bit_count) {
EXPECT_EQ(StrPrint(fmt, d), s);
}
return s;
};
// 0x8.8p+4
const long double on_boundary_even = 136.0;
EXPECT_EQ(format("%.0La", on_boundary_even), "0x8p+4");
EXPECT_EQ(format("%.1La", on_boundary_even), "0x8.8p+4");
EXPECT_EQ(format("%.2La", on_boundary_even), "0x8.80p+4");
EXPECT_EQ(format("%.3La", on_boundary_even), "0x8.800p+4");
EXPECT_EQ(format("%.4La", on_boundary_even), "0x8.8000p+4");
EXPECT_EQ(format("%.5La", on_boundary_even), "0x8.80000p+4");
EXPECT_EQ(format("%.6La", on_boundary_even), "0x8.800000p+4");
// 0x9.8p+4
const long double on_boundary_odd = 152.0;
EXPECT_EQ(format("%.0La", on_boundary_odd), "0xap+4");
EXPECT_EQ(format("%.1La", on_boundary_odd), "0x9.8p+4");
EXPECT_EQ(format("%.2La", on_boundary_odd), "0x9.80p+4");
EXPECT_EQ(format("%.3La", on_boundary_odd), "0x9.800p+4");
EXPECT_EQ(format("%.4La", on_boundary_odd), "0x9.8000p+4");
EXPECT_EQ(format("%.5La", on_boundary_odd), "0x9.80000p+4");
EXPECT_EQ(format("%.6La", on_boundary_odd), "0x9.800000p+4");
// 0x8.80001p+24
const long double slightly_over = 142606352.0;
EXPECT_EQ(format("%.0La", slightly_over), "0x9p+24");
EXPECT_EQ(format("%.1La", slightly_over), "0x8.8p+24");
EXPECT_EQ(format("%.2La", slightly_over), "0x8.80p+24");
EXPECT_EQ(format("%.3La", slightly_over), "0x8.800p+24");
EXPECT_EQ(format("%.4La", slightly_over), "0x8.8000p+24");
EXPECT_EQ(format("%.5La", slightly_over), "0x8.80001p+24");
EXPECT_EQ(format("%.6La", slightly_over), "0x8.800010p+24");
// 0x8.7ffffp+24
const long double slightly_under = 142606320.0;
EXPECT_EQ(format("%.0La", slightly_under), "0x8p+24");
EXPECT_EQ(format("%.1La", slightly_under), "0x8.8p+24");
EXPECT_EQ(format("%.2La", slightly_under), "0x8.80p+24");
EXPECT_EQ(format("%.3La", slightly_under), "0x8.800p+24");
EXPECT_EQ(format("%.4La", slightly_under), "0x8.8000p+24");
EXPECT_EQ(format("%.5La", slightly_under), "0x8.7ffffp+24");
EXPECT_EQ(format("%.6La", slightly_under), "0x8.7ffff0p+24");
EXPECT_EQ(format("%.7La", slightly_under), "0x8.7ffff00p+24");
// 0xc.0828384858688000p+128
const long double eights = 4094231060438608800781871108094404067328.0;
EXPECT_EQ(format("%.0La", eights), "0xcp+128");
EXPECT_EQ(format("%.1La", eights), "0xc.1p+128");
EXPECT_EQ(format("%.2La", eights), "0xc.08p+128");
EXPECT_EQ(format("%.3La", eights), "0xc.083p+128");
EXPECT_EQ(format("%.4La", eights), "0xc.0828p+128");
EXPECT_EQ(format("%.5La", eights), "0xc.08284p+128");
EXPECT_EQ(format("%.6La", eights), "0xc.082838p+128");
EXPECT_EQ(format("%.7La", eights), "0xc.0828385p+128");
EXPECT_EQ(format("%.8La", eights), "0xc.08283848p+128");
EXPECT_EQ(format("%.9La", eights), "0xc.082838486p+128");
EXPECT_EQ(format("%.10La", eights), "0xc.0828384858p+128");
EXPECT_EQ(format("%.11La", eights), "0xc.08283848587p+128");
EXPECT_EQ(format("%.12La", eights), "0xc.082838485868p+128");
EXPECT_EQ(format("%.13La", eights), "0xc.0828384858688p+128");
EXPECT_EQ(format("%.14La", eights), "0xc.08283848586880p+128");
EXPECT_EQ(format("%.15La", eights), "0xc.082838485868800p+128");
EXPECT_EQ(format("%.16La", eights), "0xc.0828384858688000p+128");
}
// We don't actually store the results. This is just to exercise the rest of the
// machinery.
struct NullSink {
friend void AbslFormatFlush(NullSink *, string_view) {}
};
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) {
const NativePrintfTraits &native_traits = VerifyNativeImplementation();
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' &&
f != 'a' && f != 'A') {
// This particular test takes way too long with snprintf.
// Disable for the case we are not implementing natively.
continue;
}
if (f == 'a' || f == 'A') {
if (!native_traits.hex_float_has_glibc_rounding ||
!native_traits.hex_float_optimizes_leading_digit_bit_count) {
continue;
}
}
for (auto d : doubles) {
FormatArgImpl arg(d);
UntypedFormatSpecImpl format(fmt_str);
std::string result = FormatPack(format, {&arg, 1});
#ifdef _MSC_VER
// MSVC has a different rounding policy than us so we can't test our
// implementation against the native one there.
continue;
#endif // _MSC_VER
// 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), result)
<< fmt_str << " " << StrPrint("%.18Lg", d) << " "
<< StrPrint("%La", d) << " " << StrPrint("%.1080Lf", d);
}
}
}
}
TEST_F(FormatConvertTest, IntAsDouble) {
const NativePrintfTraits &native_traits = VerifyNativeImplementation();
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);
std::vector<Expectation> expect = {
{__LINE__, StrPrint("%f", dx), "%f"},
{__LINE__, StrPrint("%12f", dx), "%12f"},
{__LINE__, StrPrint("%.12f", dx), "%.12f"},
{__LINE__, StrPrint("%.12a", dx), "%.12a"},
};
if (native_traits.hex_float_uses_minimal_precision_when_not_specified) {
Expectation ex = {__LINE__, StrPrint("%12a", dx), "%12a"};
expect.push_back(ex);
}
for (const Expectation &e : expect) {
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", ""));
}
// Sanity check to make sure that we are testing what we think we're testing on
// e.g. the x86_64+glibc platform.
TEST_F(FormatConvertTest, GlibcHasCorrectTraits) {
#if defined(__GLIBC__) && defined(__x86_64__)
constexpr bool kIsSupportedGlibc = true;
#else
constexpr bool kIsSupportedGlibc = false;
#endif
if (!kIsSupportedGlibc) {
GTEST_SKIP() << "Test does not support this platform";
}
const NativePrintfTraits &native_traits = VerifyNativeImplementation();
// If one of the following tests break then it is either because the above PP
// macro guards failed to exclude a new platform (likely) or because something
// has changed in the implementation of glibc sprintf float formatting
// behavior. If the latter, then the code that computes these flags needs to
// be revisited and/or possibly the StrFormat implementation.
EXPECT_TRUE(native_traits.hex_float_has_glibc_rounding);
EXPECT_TRUE(native_traits.hex_float_prefers_denormal_repr);
EXPECT_TRUE(
native_traits.hex_float_uses_minimal_precision_when_not_specified);
EXPECT_TRUE(native_traits.hex_float_optimizes_leading_digit_bit_count);
}
} // namespace
} // namespace str_format_internal
ABSL_NAMESPACE_END
} // namespace absl