4 files changed, 108 insertions, 14 deletions

diff --git a/tools/preproc/asm_file.cpp b/tools/preproc/asm_file.cpp
index b843d640b..eba486e66 100644
--- a/tools/preproc/asm_file.cpp
+++ b/tools/preproc/asm_file.cpp
@@ -191,6 +191,8 @@ Directive AsmFile::GetDirective()
         return Directive::Include;
     else if (CheckForDirective(".string"))
         return Directive::String;
+    else if (CheckForDirective(".braille"))
+        return Directive::Braille;
     else
         return Directive::Unknown;
 }
@@ -285,6 +287,85 @@ int AsmFile::ReadString(unsigned char* s)
     return length;
 }
 
+int AsmFile::ReadBraille(unsigned char* s)
+{
+    static std::map<char, unsigned char> encoding =
+    {
+        { 'A', 0x01 },
+        { 'B', 0x05 },
+        { 'C', 0x03 },
+        { 'D', 0x0B },
+        { 'E', 0x09 },
+        { 'F', 0x07 },
+        { 'G', 0x0F },
+        { 'H', 0x0D },
+        { 'I', 0x06 },
+        { 'J', 0x0E },
+        { 'K', 0x11 },
+        { 'L', 0x15 },
+        { 'M', 0x13 },
+        { 'N', 0x1B },
+        { 'O', 0x19 },
+        { 'P', 0x17 },
+        { 'Q', 0x1F },
+        { 'R', 0x1D },
+        { 'S', 0x16 },
+        { 'T', 0x1E },
+        { 'U', 0x31 },
+        { 'V', 0x35 },
+        { 'W', 0x2E },
+        { 'X', 0x33 },
+        { 'Y', 0x3B },
+        { 'Z', 0x39 },
+        { ' ', 0x00 },
+        { ',', 0x04 },
+        { '.', 0x2C },
+        { '$', 0xFF },
+    };
+
+    SkipWhitespace();
+
+    int length = 0;
+
+    if (m_buffer[m_pos] != '"')
+        RaiseError("expected braille string literal");
+
+    m_pos++;
+
+    while (m_buffer[m_pos] != '"')
+    {
+        if (length == kMaxStringLength)
+            RaiseError("mapped string longer than %d bytes", kMaxStringLength);
+
+        if (m_buffer[m_pos] == '\\' && m_buffer[m_pos + 1] == 'n')
+        {
+            s[length++] = 0xFE;
+            m_pos += 2;
+        }
+        else
+        {
+            char c = m_buffer[m_pos];
+
+            if (encoding.count(c) == 0)
+            {
+                if (IsAsciiPrintable(c))
+                    RaiseError("character '%c' not valid in braille string", m_buffer[m_pos]);
+                else
+                    RaiseError("character '\\x%02X' not valid in braille string", m_buffer[m_pos]);
+            }
+
+            s[length++] = encoding[c];
+            m_pos++;
+        }
+    }
+
+    m_pos++; // Go past the right quote.
+
+    ExpectEmptyRestOfLine();
+
+    return length;
+}
+
 // If we're at a comma, consumes it.
 // Returns whether a comma was found.
 bool AsmFile::ConsumeComma()
diff --git a/tools/preproc/asm_file.h b/tools/preproc/asm_file.h
index 335dbab4b..c0aba878d 100644
--- a/tools/preproc/asm_file.h
+++ b/tools/preproc/asm_file.h
@@ -30,6 +30,7 @@ enum class Directive
 {
     Include,
     String,
+    Braille,
     Unknown
 };
 
@@ -43,6 +44,7 @@ public:
     Directive GetDirective();
     std::string ReadPath();
     int ReadString(unsigned char* s);
+    int ReadBraille(unsigned char* s);
     bool IsAtEnd();
     void OutputLine();
     void OutputLocation();
diff --git a/tools/preproc/preproc.cpp b/tools/preproc/preproc.cpp
index 1dd6808c3..38ae762ea 100644
--- a/tools/preproc/preproc.cpp
+++ b/tools/preproc/preproc.cpp
@@ -27,6 +27,22 @@
 
 Charmap* g_charmap;
 
+void PrintAsmBytes(unsigned char *s, int length)
+{
+    if (length > 0)
+    {
+        printf("\t.byte ");
+        for (int i = 0; i < length; i++)
+        {
+            printf("0x%02X", s[i]);
+
+            if (i < length - 1)
+                printf(", ");
+        }
+        putchar('\n');
+    }
+}
+
 void PreprocAsmFile(std::string filename)
 {
     std::stack<AsmFile> stack;
@@ -57,19 +73,14 @@ void PreprocAsmFile(std::string filename)
         {
             unsigned char s[kMaxStringLength];
             int length = stack.top().ReadString(s);
-
-            if (length > 0)
-            {
-                printf("\t.byte ");
-                for (int i = 0; i < length; i++)
-                {
-                    printf("0x%02X", s[i]);
-
-                    if (i < length - 1)
-                        printf(", ");
-                }
-                putchar('\n');
-            }
+            PrintAsmBytes(s, length);
+            break;
+        }
+        case Directive::Braille:
+        {
+            unsigned char s[kMaxStringLength];
+            int length = stack.top().ReadBraille(s);
+            PrintAsmBytes(s, length);
             break;
         }
         case Directive::Unknown:
diff --git a/tools/preproc/string_parser.cpp b/tools/preproc/string_parser.cpp
index b383f2f4f..dd5196a44 100644
--- a/tools/preproc/string_parser.cpp
+++ b/tools/preproc/string_parser.cpp
@@ -186,7 +186,7 @@ int StringParser::ParseString(long srcPos, unsigned char* dest, int& destLength)
         for (const char& c : sequence)
         {
             if (destLength == kMaxStringLength)
-                RaiseError("mapped string longer than %d bytes", destLength);
+                RaiseError("mapped string longer than %d bytes", kMaxStringLength);
 
             dest[destLength++] = c;
         }