diff options
Diffstat (limited to 'absl/strings/internal/str_format/convert_test.cc')
| -rw-r--r-- | absl/strings/internal/str_format/convert_test.cc | 245 |
1 files changed, 217 insertions, 28 deletions
diff --git a/absl/strings/internal/str_format/convert_test.cc b/absl/strings/internal/str_format/convert_test.cc index cbcd7caf4665..dd167f76e68f 100644 --- a/absl/strings/internal/str_format/convert_test.cc +++ b/absl/strings/internal/str_format/convert_test.cc @@ -1,14 +1,18 @@ #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 @@ -57,7 +61,7 @@ std::string Esc(const T &v) { return oss.str(); } -void StrAppend(std::string *dst, const char *format, va_list ap) { +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]; @@ -98,11 +102,18 @@ void StrAppend(std::string *dst, const char *format, va_list ap) { 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; - StrAppend(&result, format, ap); + StrAppendV(&result, format, ap); va_end(ap); return result; } @@ -471,8 +482,8 @@ TEST_F(FormatConvertTest, Float) { #endif // _MSC_VER const char *const kFormats[] = { - "%", "%.3", "%8.5", "%9", "%.60", "%.30", "%03", "%+", - "% ", "%-10", "%#15.3", "%#.0", "%.0", "%1$*2$", "%1$.*2$"}; + "%", "%.3", "%8.5", "%500", "%.5000", "%.60", "%.30", "%03", + "%+", "% ", "%-10", "%#15.3", "%#.0", "%.0", "%1$*2$", "%1$.*2$"}; std::vector<double> doubles = {0.0, -0.0, @@ -489,11 +500,6 @@ TEST_F(FormatConvertTest, Float) { std::numeric_limits<double>::infinity(), -std::numeric_limits<double>::infinity()}; -#ifndef __APPLE__ - // Apple formats NaN differently (+nan) vs. (nan) - doubles.push_back(std::nan("")); -#endif - // Some regression tests. doubles.push_back(0.99999999999999989); @@ -512,43 +518,204 @@ TEST_F(FormatConvertTest, Float) { } } + // 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 + + // 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); + 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 (double d : doubles) { int i = -10; FormatArgImpl args[2] = {FormatArgImpl(d), FormatArgImpl(i)}; 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, i), - FormatPack(format, absl::MakeSpan(args))) - << fmt_str << " " << StrPrint("%.18g", d) << " " - << StrPrint("%.999f", d); + + 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("%.1080f", d); + } } } } } +TEST_F(FormatConvertTest, FloatRound) { + 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, LongDouble) { - const char *const kFormats[] = {"%", "%.3", "%8.5", "%9", +#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"}; - // 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. - long double very_precise = 10000000000000000.25L; - std::vector<long double> doubles = { 0.0, -0.0, - very_precise, - 1 / very_precise, std::numeric_limits<long double>::max(), -std::numeric_limits<long double>::max(), std::numeric_limits<long double>::min(), @@ -556,22 +723,44 @@ TEST_F(FormatConvertTest, LongDouble) { 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)); + } + } + } + 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})) + ASSERT_EQ(StrPrint(fmt_str.c_str(), d), FormatPack(format, {&arg, 1})) << fmt_str << " " << StrPrint("%.18Lg", d) << " " - << StrPrint("%.999Lf", d); + << StrPrint("%La", d) << " " << StrPrint("%.1080Lf", d); } } } |