diff --git a/platform/source/minimal-printf/mbed_printf_implementation.c b/platform/source/minimal-printf/mbed_printf_implementation.c index ba3e2538fd1..b01a5ee5b20 100644 --- a/platform/source/minimal-printf/mbed_printf_implementation.c +++ b/platform/source/minimal-printf/mbed_printf_implementation.c @@ -267,20 +267,51 @@ static void mbed_minimal_formatted_string_double(char *buffer, size_t length, in { /* get integer part */ MBED_SIGNED_STORAGE integer = value; + /* fractional part represented as the int that will be formatted after the dot, e.g. 95 for 1.95 */ + MBED_SIGNED_STORAGE decimal = 0; if (dec_precision == PRECISION_DEFAULT) { dec_precision = MBED_CONF_PLATFORM_MINIMAL_PRINTF_SET_FLOATING_POINT_MAX_DECIMALS; } if (dec_precision != 0) { + /* get decimal part */ + MBED_SIGNED_STORAGE precision = 1; + for (int index = 0; index < dec_precision; index++) { + precision *= 10; + } + + /* Multiply the frac part so we get an int value with the required accuracy. + E.g. For 0.1234 and dec_precision=3 you'd get 123.4 */ + double decimal_double = (value - integer) * precision; + if (value < 0) { + /* The part after the dot does not have a sign, so negate the value before rounding */ + decimal = -decimal_double + 0.5; + if (decimal >= precision) { + /* Rounding carries over to value's integer part (e.g. -1.95 with dec_precision=1 -> -2.0) */ + integer--; + decimal = 0; + } + } else { + /* Round the value */ + decimal = decimal_double + 0.5; + if (decimal >= precision) { + /* Rounding carries over to value's integer part (e.g. 1.95 with dec_precision=1 -> 2.0) */ + integer++; + decimal = 0; + } + } + width_size -= dec_precision + 1; // decimal precision plus '.' if (width_size < 0) { width_size = 0; } } else { value = (value - integer) * 1.0; - if (!((value > -0.5) && (value < 0.5))) { + if (value > 0.5) { integer++; + } else if (value < -0.5) { + integer--; } } @@ -294,30 +325,6 @@ static void mbed_minimal_formatted_string_double(char *buffer, size_t length, in if (dec_precision != 0) { /* write decimal point */ mbed_minimal_putchar(buffer, length, result, '.', stream); - - /* get decimal part */ - double precision = 1.0; - - for (size_t index = 0; index < dec_precision; index++) { - precision *= 10; - } - - value = (value - integer) * precision; - - /* convert to positive number */ - if (value < 0.0) { - value *= -1.0; - } - - MBED_UNSIGNED_STORAGE decimal = value; - - /* round up or down */ - value -= decimal; - - if (!((value > -0.5) && (value < 0.5))) { - decimal++; - } - /* write decimal part */ mbed_minimal_formatted_string_integer(buffer, length, result, decimal, INT_UNSIGNED, dec_precision, true, stream); } diff --git a/platform/tests/UNITTESTS/CMakeLists.txt b/platform/tests/UNITTESTS/CMakeLists.txt index 88b941022a0..e7038fa4c4e 100644 --- a/platform/tests/UNITTESTS/CMakeLists.txt +++ b/platform/tests/UNITTESTS/CMakeLists.txt @@ -4,3 +4,4 @@ add_subdirectory(doubles) add_subdirectory(ATCmdParser) add_subdirectory(CircularBuffer) +add_subdirectory(minimal-printf) diff --git a/platform/tests/UNITTESTS/minimal-printf/CMakeLists.txt b/platform/tests/UNITTESTS/minimal-printf/CMakeLists.txt new file mode 100644 index 00000000000..08a95696117 --- /dev/null +++ b/platform/tests/UNITTESTS/minimal-printf/CMakeLists.txt @@ -0,0 +1,27 @@ +# Copyright (c) 2021 ARM Limited. All rights reserved. +# SPDX-License-Identifier: Apache-2.0 + +set(TEST_NAME minimal-printf-unittest) + +add_executable(${TEST_NAME}) + +target_sources(${TEST_NAME} + PRIVATE + ${mbed-os_SOURCE_DIR}/platform/source/minimal-printf/mbed_printf_implementation.c + test_minimal-printf-implementation.cpp +) + +target_include_directories(mbed-headers-platform + INTERFACE + ${mbed-os_SOURCE_DIR}/platform/source/minimal-printf +) + +target_link_libraries(${TEST_NAME} + PRIVATE + mbed-stubs-platform + gmock_main +) + +add_test(NAME "${TEST_NAME}" COMMAND ${TEST_NAME}) + +set_tests_properties(${TEST_NAME} PROPERTIES LABELS "platform") diff --git a/platform/tests/UNITTESTS/minimal-printf/test_minimal-printf-implementation.cpp b/platform/tests/UNITTESTS/minimal-printf/test_minimal-printf-implementation.cpp new file mode 100644 index 00000000000..78e39de4b00 --- /dev/null +++ b/platform/tests/UNITTESTS/minimal-printf/test_minimal-printf-implementation.cpp @@ -0,0 +1,144 @@ +/* + * Copyright (c) 2019, Arm Limited and affiliates. + * SPDX-License-Identifier: Apache-2.0 + * + * 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 + * + * http://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 +#include +#include "gtest/gtest.h" + +/* "mbed_printf_implementation.h" does not declare it as extern "C", so pull it in manually */ +extern "C" int mbed_minimal_formatted_string(char *buffer, size_t length, const char *format, va_list arguments, FILE *stream); + +namespace +{ + std::string format(const char *fmt, ...) + { + va_list arguments; + va_start(arguments, fmt); + + constexpr int buf_size = 128; + char buffer[buf_size]; + int n = mbed_minimal_formatted_string(buffer, buf_size, fmt, arguments, nullptr); + va_end(arguments); + + if (n >= buf_size) { + return "overflow"; + } + + return std::string(buffer); + } +} + +TEST(minimal_printf, floats) +{ + /* std::nextafter is used for the values below to make sure the numbers are + floating point representations of at least the value we want to test. + This hopefully mitigates false failures due to different floating point + implementations */ + + /* Positive numbers */ + float value = std::nextafter(1.5f, 0.0f); /* Something like 1.499999, i.e just below 1.5 */ + EXPECT_EQ("1", format("%.0f", value)); + EXPECT_EQ("1.5", format("%.1f", value)); + EXPECT_EQ("1.50", format("%.2f", value)); + EXPECT_EQ("1.500", format("%.3f", value)); + EXPECT_EQ("1.5000", format("%.4f", value)); + EXPECT_EQ("1.50000", format("%.5f", value)); + EXPECT_EQ("1.500000", format("%.6f", value)); + + value = std::nextafter(1.5f, 2.0f); /* Something like 1.500001, i.e just above 1.5 */ + EXPECT_EQ("2", format("%.0f", value)); + EXPECT_EQ("1.5", format("%.1f", value)); + EXPECT_EQ("1.50", format("%.2f", value)); + EXPECT_EQ("1.500", format("%.3f", value)); + EXPECT_EQ("1.5000", format("%.4f", value)); + EXPECT_EQ("1.50000", format("%.5f", value)); + EXPECT_EQ("1.500000", format("%.6f", value)); + + value = std::nextafter(2.0f, 0.0f); /* Something like 1.999999, i.e just below 2.0 */ + EXPECT_EQ("2", format("%.0f", value)); + EXPECT_EQ("2.0", format("%.1f", value)); + EXPECT_EQ("2.00", format("%.2f", value)); + EXPECT_EQ("2.000", format("%.3f", value)); + EXPECT_EQ("2.0000", format("%.4f", value)); + EXPECT_EQ("2.00000", format("%.5f", value)); + EXPECT_EQ("2.000000", format("%.6f", value)); + + /* Negative numbers */ + value = std::nextafter(-1.5f, 0.0f); /* Something like -1.499999, i.e just above -1.5 */ + EXPECT_EQ("-1", format("%.0f", value)); + EXPECT_EQ("-1.5", format("%.1f", value)); + EXPECT_EQ("-1.50", format("%.2f", value)); + EXPECT_EQ("-1.500", format("%.3f", value)); + EXPECT_EQ("-1.5000", format("%.4f", value)); + EXPECT_EQ("-1.50000", format("%.5f", value)); + EXPECT_EQ("-1.500000", format("%.6f", value)); + + value = std::nextafter(-1.5f, -2.0f); /* Something like -1.500001, i.e just below -1.5 */ + EXPECT_EQ("-2", format("%.0f", value)); + EXPECT_EQ("-1.5", format("%.1f", value)); + EXPECT_EQ("-1.50", format("%.2f", value)); + EXPECT_EQ("-1.500", format("%.3f", value)); + EXPECT_EQ("-1.5000", format("%.4f", value)); + EXPECT_EQ("-1.50000", format("%.5f", value)); + EXPECT_EQ("-1.500000", format("%.6f", value)); + + value = std::nextafter(-2.0f, 0.0f); /* Something like -1.999999, i.e just above -2.0 */ + EXPECT_EQ("-2", format("%.0f", value)); + EXPECT_EQ("-2.0", format("%.1f", value)); + EXPECT_EQ("-2.00", format("%.2f", value)); + EXPECT_EQ("-2.000", format("%.3f", value)); + EXPECT_EQ("-2.0000", format("%.4f", value)); + EXPECT_EQ("-2.00000", format("%.5f", value)); + EXPECT_EQ("-2.000000", format("%.6f", value)); + + // And some near zero stuff + EXPECT_EQ("-0", format("%.0f", std::nextafter(0.0f, -1.0f))); + EXPECT_EQ("0", format("%.0f", 0.0)); + EXPECT_EQ("0", format("%.0f", std::nextafter(0.0f, 1.0f))); +} + +TEST(minimal_printf, padding) +{ + // Right aligned integers + EXPECT_EQ("12", format("%1d", 12)); + EXPECT_EQ("12", format("%2d", 12)); + EXPECT_EQ(" 12", format("%3d", 12)); + EXPECT_EQ(" 12", format("%4d", 12)); + + EXPECT_EQ("-12", format("%1d", -12)); + EXPECT_EQ("-12", format("%3d", -12)); + EXPECT_EQ(" -12", format("%4d", -12)); + EXPECT_EQ(" -12", format("%5d", -12)); + + EXPECT_EQ("0012", format("%04d", 12)); + EXPECT_EQ("-012", format("%04d", -12)); + + // Right aligned floats + EXPECT_EQ("12.3", format("%1.1f", 12.345f)); + EXPECT_EQ("12.3", format("%4.1f", 12.345)); + EXPECT_EQ(" 12.3", format("%5.1f", 12.345)); + EXPECT_EQ(" 12.3", format("%6.1f", 12.345)); + + EXPECT_EQ("-12.3", format("%1.1f", -12.345f)); + EXPECT_EQ("-12.3", format("%4.1f", -12.345)); + EXPECT_EQ(" -12.3", format("%6.1f", -12.345)); + EXPECT_EQ(" -12.3", format("%7.1f", -12.345)); + + EXPECT_EQ("012.3", format("%05.1f", 12.345)); + EXPECT_EQ("-012.3", format("%06.1f", -12.345)); +} +