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| -rw-r--r-- | Userland/printf.cpp | 303 |
1 files changed, 303 insertions, 0 deletions
diff --git a/Userland/printf.cpp b/Userland/printf.cpp new file mode 100644 index 0000000000..494abb9869 --- /dev/null +++ b/Userland/printf.cpp @@ -0,0 +1,303 @@ +/* + * Copyright (c) 2020, the SerenityOS developers. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, this + * list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include <AK/PrintfImplementation.h> +#include <AK/String.h> +#include <AK/StringBuilder.h> +#include <AK/Types.h> +#include <stdio.h> +#include <unistd.h> + +[[gnu::noreturn]] static void fail(const char* message) +{ + fputs("\e[31m", stderr); + fputs(message, stderr); + fputs("\e[0m\n", stderr); + exit(1); +} + +template<typename PutChFunc, typename ArgumentListRefT, template<typename T, typename U = ArgumentListRefT> typename NextArgument> +struct PrintfImpl : public PrintfImplementation::PrintfImpl<PutChFunc, ArgumentListRefT, NextArgument> { + ALWAYS_INLINE PrintfImpl(PutChFunc& putch, char*& bufptr, const int& nwritten) + : PrintfImplementation::PrintfImpl<PutChFunc, ArgumentListRefT, NextArgument>(putch, bufptr, nwritten) + { + } + + ALWAYS_INLINE int format_b(const PrintfImplementation::ModifierState&, ArgumentListRefT&) const + { + fail("format specifier 'b' is not supported"); + } + ALWAYS_INLINE int format_q(const PrintfImplementation::ModifierState& state, ArgumentListRefT& ap) const + { + auto state_copy = state; + auto str = NextArgument<const char*>()(ap); + if (!str) + str = "(null)"; + + constexpr auto make_len_or_escape = [](auto str, bool mk_len, size_t field_width, auto putc) { + unsigned len = 2; + if (!mk_len) + putc('"'); + + for (size_t i = 0; str[i] && (mk_len ? true : (field_width >= len)); ++i) { + auto ch = str[i]; + switch (ch) { + case '"': + case '$': + case '\\': + ++len; + if (!mk_len) + putc('\\'); + } + ++len; + if (!mk_len) + putc(ch); + } + + if (!mk_len) + putc('"'); + + return len; + }; + + auto len = make_len_or_escape(str, true, state_copy.field_width, [&](auto c) { this->m_putch(this->m_bufptr, c); }); + + if (!state_copy.dot && (!state_copy.field_width || state_copy.field_width < len)) + state_copy.field_width = len; + size_t pad_amount = state_copy.field_width > len ? state_copy.field_width - len : 0; + + if (!state_copy.left_pad) { + for (size_t i = 0; i < pad_amount; ++i) + this->m_putch(this->m_bufptr, ' '); + } + + make_len_or_escape(str, false, state_copy.field_width, [&](auto c) { this->m_putch(this->m_bufptr, c); }); + + if (state_copy.left_pad) { + for (size_t i = 0; i < pad_amount; ++i) + this->m_putch(this->m_bufptr, ' '); + } + + return state_copy.field_width; + } +}; + +template<typename T, typename V> +struct ArgvNextArgument { + ALWAYS_INLINE T operator()(V) const + { + static_assert(sizeof(V) != sizeof(V), "Base instantiated"); + return declval<T>(); + } +}; + +template<typename V> +struct ArgvNextArgument<char*, V> { + ALWAYS_INLINE char* operator()(V arg) const + { + if (arg.argc == 0) + fail("Not enough arguments"); + + auto result = *arg.argv++; + --arg.argc; + return result; + } +}; + +template<typename V> +struct ArgvNextArgument<const char*, V> { + ALWAYS_INLINE const char* operator()(V arg) const + { + if (arg.argc == 0) + return ""; + + auto result = *arg.argv++; + --arg.argc; + return result; + } +}; + +template<typename V> +struct ArgvNextArgument<int, V> { + ALWAYS_INLINE int operator()(V arg) const + { + if (arg.argc == 0) + return 0; + + auto result = *arg.argv++; + --arg.argc; + return atoi(result); + } +}; + +template<typename V> +struct ArgvNextArgument<unsigned, V> { + ALWAYS_INLINE unsigned operator()(V arg) const + { + if (arg.argc == 0) + return 0; + + auto result = *arg.argv++; + --arg.argc; + return strtoul(result, nullptr, 10); + } +}; + +template<typename V> +struct ArgvNextArgument<i64, V> { + ALWAYS_INLINE i64 operator()(V arg) const + { + if (arg.argc == 0) + return 0; + + auto result = *arg.argv++; + --arg.argc; + return strtoll(result, nullptr, 10); + } +}; + +template<typename V> +struct ArgvNextArgument<u64, V> { + ALWAYS_INLINE u64 operator()(V arg) const + { + if (arg.argc == 0) + return 0; + + auto result = *arg.argv++; + --arg.argc; + return strtoull(result, nullptr, 10); + } +}; + +template<typename V> +struct ArgvNextArgument<double, V> { + ALWAYS_INLINE double operator()(V arg) const + { + if (arg.argc == 0) + return 0; + + auto result = *arg.argv++; + --arg.argc; + return strtod(result, nullptr); + } +}; + +template<typename V> +struct ArgvNextArgument<int*, V> { + ALWAYS_INLINE int* operator()(V) const + { + ASSERT_NOT_REACHED(); + return nullptr; + } +}; + +struct ArgvWithCount { + char**& argv; + int& argc; +}; + +static String handle_escapes(const char* string) +{ + StringBuilder builder; + for (auto c = *string; c; c = *++string) { + if (c == '\\') { + if (string[1]) { + switch (c = *++string) { + case '\\': + case '"': + builder.append(c); + break; + case 'a': + builder.append('\a'); + break; + case 'b': + builder.append('\b'); + break; + case 'c': + return builder.build(); + case 'e': + builder.append('\e'); + break; + case 'f': + builder.append('\f'); + break; + case 'n': + builder.append('\n'); + break; + case 'r': + builder.append('\r'); + break; + case 't': + builder.append('\t'); + break; + case 'v': + builder.append('\v'); + break; + case 'x': + fail("Unsupported escape '\\x'"); + case 'u': + fail("Unsupported escape '\\u'"); + case 'U': + fail("Unsupported escape '\\U'"); + default: + builder.append(c); + } + } else { + builder.append(c); + } + } else { + builder.append(c); + } + } + + return builder.build(); +} + +int main(int argc, char** argv) +{ + if (argc < 2) + return 1; + + ++argv; + String format = handle_escapes(*(argv++)); + auto format_string = format.characters(); + + argc -= 2; + + ArgvWithCount arg { argv, argc }; + + auto putch = [](auto*, auto ch) { + putchar(ch); + }; + + auto previous_argc = 0; + do { + previous_argc = argc; + PrintfImplementation::printf_internal<decltype(putch), PrintfImpl, ArgvWithCount, ArgvNextArgument>(putch, nullptr, format_string, arg); + } while (argc && previous_argc != argc); + + return 0; +} |