ladybird/Userland/printf.cpp
2020-09-11 21:41:23 +02:00

303 lines
8.4 KiB
C++

/*
* 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;
}