1 files changed, 355 insertions, 0 deletions
diff --git a/tools/preproc/string_parser.cpp b/tools/preproc/string_parser.cpp
new file mode 100644
index 0000000..dd5196a
--- /dev/null
+++ b/tools/preproc/string_parser.cpp
@@ -0,0 +1,355 @@
+// 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 <cstdarg>
+#include <stdexcept>
+#include "preproc.h"
+#include "string_parser.h"
+#include "char_util.h"
+#include "utf8.h"
+
+// Reads a charmap char or escape sequence.
+std::string StringParser::ReadCharOrEscape()
+{
+    std::string sequence;
+
+    bool isEscape = (m_buffer[m_pos] == '\\');
+
+    if (isEscape)
+    {
+        m_pos++;
+
+        if (m_buffer[m_pos] == '"')
+        {
+            sequence = g_charmap->Char('"');
+
+            if (sequence.length() == 0)
+                RaiseError("no mapping exists for double quote");
+
+            return sequence;
+        }
+        else if (m_buffer[m_pos] == '\\')
+        {
+            sequence = g_charmap->Char('\\');
+
+            if (sequence.length() == 0)
+                RaiseError("no mapping exists for backslash");
+
+            return sequence;
+        }
+    }
+
+    unsigned char c = m_buffer[m_pos];
+
+    if (c == 0)
+    {
+        if (m_pos >= m_size)
+            RaiseError("unexpected EOF in UTF-8 string");
+        else
+            RaiseError("unexpected null character in UTF-8 string");
+    }
+
+    if (IsAscii(c) && !IsAsciiPrintable(c))
+        RaiseError("unexpected character U+%X in UTF-8 string", c);
+
+    UnicodeChar unicodeChar = DecodeUtf8(&m_buffer[m_pos]);
+    m_pos += unicodeChar.encodingLength;
+    std::int32_t code = unicodeChar.code;
+
+    if (code == -1)
+        RaiseError("invalid encoding in UTF-8 string");
+
+    if (isEscape && code >= 128)
+        RaiseError("escapes using non-ASCII characters are invalid");
+
+    sequence = isEscape ? g_charmap->Escape(code) : g_charmap->Char(code);
+
+    if (sequence.length() == 0)
+    {
+        if (isEscape)
+            RaiseError("unknown escape '\\%c'", code);
+        else
+            RaiseError("unknown character U+%X", code);
+    }
+
+    return sequence;
+}
+
+// Reads a charmap constant, i.e. "{FOO}".
+std::string StringParser::ReadBracketedConstants()
+{
+    std::string totalSequence;
+
+    m_pos++; // Assume we're on the left curly bracket.
+
+    while (m_buffer[m_pos] != '}')
+    {
+        SkipWhitespace();
+
+        if (IsIdentifierStartingChar(m_buffer[m_pos]))
+        {
+            long startPos = m_pos;
+
+            m_pos++;
+
+            while (IsIdentifierChar(m_buffer[m_pos]))
+                m_pos++;
+
+            std::string sequence = g_charmap->Constant(std::string(&m_buffer[startPos], m_pos - startPos));
+
+            if (sequence.length() == 0)
+            {
+                m_buffer[m_pos] = 0;
+                RaiseError("unknown constant '%s'", &m_buffer[startPos]);
+            }
+
+            totalSequence += sequence;
+        }
+        else if (IsAsciiDigit(m_buffer[m_pos]))
+        {
+            Integer integer = ReadInteger();
+
+            switch (integer.size)
+            {
+            case 1:
+                totalSequence += (unsigned char)integer.value;
+                break;
+            case 2:
+                totalSequence += (unsigned char)integer.value;
+                totalSequence += (unsigned char)(integer.value >> 8);
+                break;
+            case 4:
+                totalSequence += (unsigned char)integer.value;
+                totalSequence += (unsigned char)(integer.value >> 8);
+                totalSequence += (unsigned char)(integer.value >> 16);
+                totalSequence += (unsigned char)(integer.value >> 24);
+                break;
+            }
+        }
+        else if (m_buffer[m_pos] == 0)
+        {
+            if (m_pos >= m_size)
+                RaiseError("unexpected EOF after left curly bracket");
+            else
+                RaiseError("unexpected null character within curly brackets");
+        }
+        else
+        {
+            if (IsAsciiPrintable(m_buffer[m_pos]))
+                RaiseError("unexpected character '%c' within curly brackets", m_buffer[m_pos]);
+            else
+                RaiseError("unexpected character '\\x%02X' within curly brackets", m_buffer[m_pos]);
+        }
+    }
+
+    m_pos++; // Go past the right curly bracket.
+
+    return totalSequence;
+}
+
+// Reads a charmap string.
+int StringParser::ParseString(long srcPos, unsigned char* dest, int& destLength)
+{
+    m_pos = srcPos;
+
+    if (m_buffer[m_pos] != '"')
+        RaiseError("expected UTF-8 string literal");
+
+    long start = m_pos;
+
+    m_pos++;
+
+    destLength = 0;
+
+    while (m_buffer[m_pos] != '"')
+    {
+        std::string sequence = (m_buffer[m_pos] == '{') ? ReadBracketedConstants() : ReadCharOrEscape();
+
+        for (const char& c : sequence)
+        {
+            if (destLength == kMaxStringLength)
+                RaiseError("mapped string longer than %d bytes", kMaxStringLength);
+
+            dest[destLength++] = c;
+        }
+    }
+
+    m_pos++; // Go past the right quote.
+
+    return m_pos - start;
+}
+
+void StringParser::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);
+
+    throw std::runtime_error(buffer);
+}
+
+// Converts digit character to numerical value.
+static int ConvertDigit(char c, int radix)
+{
+    int digit;
+
+    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';
+    else
+        return -1;
+
+    return (digit < radix) ? digit : -1;
+}
+
+void StringParser::SkipRestOfInteger(int radix)
+{
+    while (ConvertDigit(m_buffer[m_pos], radix) != -1)
+        m_pos++;
+}
+
+StringParser::Integer StringParser::ReadDecimal()
+{
+    const int radix = 10;
+    std::uint64_t n = 0;
+    int digit;
+    std::uint64_t max = UINT32_MAX;
+    long startPos = m_pos;
+
+    while ((digit = ConvertDigit(m_buffer[m_pos], radix)) != -1)
+    {
+        n = n * radix + digit;
+
+        if (n >= max)
+        {
+            SkipRestOfInteger(radix);
+
+            std::string intLiteral(m_buffer + startPos, m_pos - startPos);
+            RaiseError("integer literal \"%s\" is too large", intLiteral.c_str());
+        }
+
+        m_pos++;
+    }
+
+    int size;
+
+    if (m_buffer[m_pos] == 'H')
+    {
+        if (n >= 0x10000)
+        {
+            RaiseError("%lu is too large to be a halfword", (unsigned long)n);
+        }
+
+        size = 2;
+        m_pos++;
+    }
+    else if (m_buffer[m_pos] == 'W')
+    {
+        size = 4;
+        m_pos++;
+    }
+    else
+    {
+        if (n >= 0x10000)
+            size = 4;
+        else if (n >= 0x100)
+            size = 2;
+        else
+            size = 1;
+    }
+
+    return{ static_cast<std::uint32_t>(n), size };
+}
+
+StringParser::Integer StringParser::ReadHex()
+{
+    const int radix = 16;
+    std::uint64_t n = 0;
+    int digit;
+    std::uint64_t max = UINT32_MAX;
+    long startPos = m_pos;
+
+    while ((digit = ConvertDigit(m_buffer[m_pos], radix)) != -1)
+    {
+        n = n * radix + digit;
+
+        if (n >= max)
+        {
+            SkipRestOfInteger(radix);
+
+            std::string intLiteral(m_buffer + startPos, m_pos - startPos);
+            RaiseError("integer literal \"%s\" is too large", intLiteral.c_str());
+        }
+
+        m_pos++;
+    }
+
+    int length = m_pos - startPos;
+    int size = 0;
+
+    switch (length)
+    {
+    case 2:
+        size = 1;
+        break;
+    case 4:
+        size = 2;
+        break;
+    case 8:
+        size = 4;
+        break;
+    default:
+    {
+        std::string intLiteral(m_buffer + startPos, m_pos - startPos);
+        RaiseError("hex integer literal \"0x%s\" doesn't have length of 2, 4, or 8 digits", intLiteral.c_str());
+    }
+    }
+
+    return{ static_cast<std::uint32_t>(n), size };
+}
+
+StringParser::Integer StringParser::ReadInteger()
+{
+    if (!IsAsciiDigit(m_buffer[m_pos]))
+        RaiseError("expected integer");
+
+    if (m_buffer[m_pos] == '0' && m_buffer[m_pos + 1] == 'x')
+    {
+        m_pos += 2;
+        return ReadHex();
+    }
+
+    return ReadDecimal();
+}
+
+// Skips tabs and spaces.
+void StringParser::SkipWhitespace()
+{
+    while (m_buffer[m_pos] == '\t' || m_buffer[m_pos] == ' ')
+        m_pos++;
+}