tumbledemerald-legacy/tools/preproc/charmap.cpp

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2022-05-19 19:14:13 +02:00
// Copyright(c) 2016 YamaArashi
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
#include <cstdio>
#include <cstdint>
#include <cstdarg>
#include "preproc.h"
#include "charmap.h"
#include "char_util.h"
#include "utf8.h"
enum LhsType
{
Char,
Escape,
Constant,
None
};
struct Lhs
{
LhsType type;
std::string name;
std::int32_t code;
};
class CharmapReader
{
public:
CharmapReader(std::string filename);
CharmapReader(const CharmapReader&) = delete;
~CharmapReader();
Lhs ReadLhs();
void ExpectEqualsSign();
std::string ReadSequence();
void ExpectEmptyRestOfLine();
void RaiseError(const char* format, ...);
private:
char* m_buffer;
long m_pos;
long m_size;
long m_lineNum;
std::string m_filename;
void RemoveComments();
std::string ReadConstant();
void SkipWhitespace();
};
CharmapReader::CharmapReader(std::string filename) : m_filename(filename)
{
FILE *fp = std::fopen(filename.c_str(), "rb");
if (fp == NULL)
FATAL_ERROR("Failed to open \"%s\" for reading.\n", filename.c_str());
std::fseek(fp, 0, SEEK_END);
m_size = std::ftell(fp);
if (m_size < 0)
FATAL_ERROR("File size of \"%s\" is less than zero.\n", filename.c_str());
m_buffer = new char[m_size + 1];
std::rewind(fp);
if (std::fread(m_buffer, m_size, 1, fp) != 1)
FATAL_ERROR("Failed to read \"%s\".\n", filename.c_str());
m_buffer[m_size] = 0;
std::fclose(fp);
m_pos = 0;
m_lineNum = 1;
RemoveComments();
}
CharmapReader::~CharmapReader()
{
delete[] m_buffer;
}
Lhs CharmapReader::ReadLhs()
{
Lhs lhs;
for (;;)
{
SkipWhitespace();
if (m_buffer[m_pos] == '\n')
{
m_pos++;
m_lineNum++;
}
else
{
break;
}
}
if (m_buffer[m_pos] == '\'')
{
m_pos++;
bool isEscape = (m_buffer[m_pos] == '\\');
if (isEscape)
{
m_pos++;
}
unsigned char c = m_buffer[m_pos];
if (c == 0)
{
if (m_pos >= m_size)
RaiseError("unexpected EOF in UTF-8 character literal");
else
RaiseError("unexpected null character in UTF-8 character literal");
}
if (IsAscii(c) && !IsAsciiPrintable(c))
RaiseError("unexpected character U+%X in UTF-8 character literal", c);
UnicodeChar unicodeChar = DecodeUtf8(&m_buffer[m_pos]);
std::int32_t code = unicodeChar.code;
if (code == -1)
RaiseError("invalid encoding in UTF-8 character literal");
m_pos += unicodeChar.encodingLength;
if (m_buffer[m_pos] != '\'')
RaiseError("unterminated character literal");
m_pos++;
lhs.code = code;
if (isEscape)
{
if (code >= 128)
RaiseError("escapes using non-ASCII characters are invalid");
switch (code)
{
case '\'':
lhs.type = LhsType::Char;
break;
case '\\':
lhs.type = LhsType::Char;
case '"':
RaiseError("cannot escape double quote");
break;
default:
lhs.type = LhsType::Escape;
}
}
else
{
if (code == '\'')
RaiseError("empty character literal");
lhs.type = LhsType::Char;
}
}
else if (IsIdentifierStartingChar(m_buffer[m_pos]))
{
lhs.type = LhsType::Constant;
lhs.name = ReadConstant();
}
else if (m_buffer[m_pos] == '\r')
{
RaiseError("only Unix-style LF newlines are supported");
}
else if (m_buffer[m_pos] == 0)
{
if (m_pos < m_size)
RaiseError("unexpected null character");
lhs.type = LhsType::None;
}
else
{
RaiseError("junk at start of line");
}
return lhs;
}
void CharmapReader::ExpectEqualsSign()
{
SkipWhitespace();
if (m_buffer[m_pos] != '=')
RaiseError("expected equals sign");
m_pos++;
}
static unsigned int ConvertHexDigit(char c)
{
unsigned int digit = 0;
if (c >= '0' && c <= '9')
digit = c - '0';
else if (c >= 'A' && c <= 'F')
digit = 10 + c - 'A';
else if (c >= 'a' && c <= 'f')
digit = 10 + c - 'a';
return digit;
}
std::string CharmapReader::ReadSequence()
{
SkipWhitespace();
long startPos = m_pos;
unsigned int length = 0;
while (IsAsciiHexDigit(m_buffer[m_pos]) && IsAsciiHexDigit(m_buffer[m_pos + 1]))
{
m_pos += 2;
length++;
if (length > kMaxCharmapSequenceLength)
RaiseError("byte sequence too long (max is %lu bytes)", kMaxCharmapSequenceLength);
SkipWhitespace();
}
if (IsAsciiHexDigit(m_buffer[m_pos]))
RaiseError("each byte must have 2 hex digits");
if (length == 0)
RaiseError("expected byte sequence");
std::string sequence;
sequence.reserve(length);
m_pos = startPos;
for (unsigned int i = 0; i < length; i++)
{
unsigned int digit1 = ConvertHexDigit(m_buffer[m_pos]);
unsigned int digit2 = ConvertHexDigit(m_buffer[m_pos + 1]);
unsigned char byte = digit1 * 16 + digit2;
sequence += byte;
m_pos += 2;
SkipWhitespace();
}
return sequence;
}
void CharmapReader::ExpectEmptyRestOfLine()
{
SkipWhitespace();
if (m_buffer[m_pos] == 0)
{
if (m_pos < m_size)
RaiseError("unexpected null character");
}
else if (m_buffer[m_pos] == '\n')
{
m_pos++;
m_lineNum++;
}
else if (m_buffer[m_pos] == '\r')
{
RaiseError("only Unix-style LF newlines are supported");
}
else
{
RaiseError("junk at end of line");
}
}
void CharmapReader::RaiseError(const char* format, ...)
{
const int bufferSize = 1024;
char buffer[bufferSize];
std::va_list args;
va_start(args, format);
std::vsnprintf(buffer, bufferSize, format, args);
va_end(args);
std::fprintf(stderr, "%s:%ld: error: %s\n", m_filename.c_str(), m_lineNum, buffer);
std::exit(1);
}
void CharmapReader::RemoveComments()
{
long pos = 0;
bool inString = false;
for (;;)
{
if (m_buffer[pos] == 0)
return;
if (inString)
{
if (m_buffer[pos] == '\\' && m_buffer[pos + 1] == '\'')
{
pos += 2;
}
else
{
if (m_buffer[pos] == '\'')
inString = false;
pos++;
}
}
else if (m_buffer[pos] == '@')
{
while (m_buffer[pos] != '\n' && m_buffer[pos] != 0)
m_buffer[pos++] = ' ';
}
else
{
if (m_buffer[pos] == '\'')
inString = true;
pos++;
}
}
}
std::string CharmapReader::ReadConstant()
{
long startPos = m_pos;
while (IsIdentifierChar(m_buffer[m_pos]))
m_pos++;
return std::string(&m_buffer[startPos], m_pos - startPos);
}
void CharmapReader::SkipWhitespace()
{
while (m_buffer[m_pos] == '\t' || m_buffer[m_pos] == ' ')
m_pos++;
}
Charmap::Charmap(std::string filename)
{
CharmapReader reader(filename);
for (;;)
{
Lhs lhs = reader.ReadLhs();
if (lhs.type == LhsType::None)
return;
reader.ExpectEqualsSign();
std::string sequence = reader.ReadSequence();
switch (lhs.type)
{
case LhsType::Char:
if (m_chars.find(lhs.code) != m_chars.end())
reader.RaiseError("redefining char");
m_chars[lhs.code] = sequence;
break;
case LhsType::Escape:
if (m_escapes[lhs.code].length() != 0)
reader.RaiseError("redefining escape");
m_escapes[lhs.code] = sequence;
break;
case LhsType::Constant:
if (m_constants.find(lhs.name) != m_constants.end())
reader.RaiseError("redefining constant");
m_constants[lhs.name] = sequence;
break;
}
reader.ExpectEmptyRestOfLine();
}
}