internal static List <token> Process(string input, Dictionary <string, List <token> > defines, Program.IncludeFileLocator file_locator)
{
/* The C standard defines eight phases of translation
*
* The first four are handled by the preprocessor:
* - Trigraph replacement
* - Line splicing (joining lines separated by the \ character)
* - Tokenization + replacing comments with whitespace
* - Marco expansion and directive handling
*/
string post_trigraph = Replace(input, new string[][] {
new string[] { "??=", "#" },
new string[] { "??/", "\\" },
new string[] { "??'", "^" },
new string[] { "??(", "[" },
new string[] { "??)", "]" },
new string[] { "??!", "|" },
new string[] { "??<", "{" },
new string[] { "??>", "}" },
new string[] { "??-", "~" },
}, false);
string spliced_lines = SpliceLines(post_trigraph);
List <token> tokens = Tokenize(spliced_lines);
int i = 0;
List <token> expanded_tokens = ConvertToTree(tokens, ref i);
List <token> new_tokens = HandleDirectives(expanded_tokens, defines, file_locator);
return(new_tokens);
}
private static void HandleInclude(List <token> ret, List <token> tokens, int i, Dictionary <string, List <token> > defines, Program.IncludeFileLocator file_locator)
{
token file_name = tokens[i].parameters[0];
if (file_name.value == "<")
{
file_name = new token {
type = token.token_type.identifier, value = tokens[i].value.Split(' ', '\t')[1].Trim()
}
}
;
if ((file_name.type != token.token_type.identifier) && (file_name.type != token.token_type.string_literal))
{
throw new Exception();
}
bool search_cur_dir = false;
if (file_name.value.StartsWith("\""))
{
search_cur_dir = true;
}
string fname = file_name.value.Trim('\"', '<', '>');
string file_text = file_locator.ReadFile(fname, search_cur_dir);
ret.AddRange(Process(file_text, defines, file_locator));
}
private static void HandlePragma(List <token> ret, List <token> tokens, int i, Dictionary <string, List <token> > defines, Program.IncludeFileLocator file_locator)
{
throw new NotImplementedException();
}
private static void HandleDefine(List <token> ret, List <token> tokens, int i, Dictionary <string, List <token> > defines, Program.IncludeFileLocator file_locator)
{
token macro_name = tokens[i].parameters[0];
List <token> defined_as = new List <token>();
for (int j = 1; j < tokens[i].parameters.Count; j++)
{
defined_as.Add(tokens[i].parameters[j]);
}
List <token> new_defined_as = HandleDirectives(defined_as, defines, file_locator);
defines[macro_name.value] = new_defined_as;
}
private static void HandleIfDef(List <token> ret, List <token> tokens, int i, Dictionary <string, List <token> > defines, Program.IncludeFileLocator file_locator)
{
if (tokens[i].parameters.Count != 1)
{
throw new Exception();
}
if (defines.ContainsKey(tokens[i].parameters[0].value))
{
ret.AddRange(HandleDirectives(tokens[i].if_tokens, defines, file_locator));
}
else
{
ret.AddRange(HandleDirectives(tokens[i].else_tokens, defines, file_locator));
}
}
private static List <token> HandleDirectives(List <token> tokens, Dictionary <string, List <token> > defines, Program.IncludeFileLocator file_locator)
{
List <token> ret = new List <token>();
if (tokens == null)
{
return(ret);
}
for (int i = 0; i < tokens.Count; i++)
{
token tok = tokens[i];
if (tok.type == token.token_type.preprocessor_directive)
{
string directive = tok.directive;
if (directive == "#include")
{
HandleInclude(ret, tokens, i, defines, file_locator);
}
else if (directive == "#if")
{
HandleIf(ret, tokens, i, defines, file_locator);
}
else if (directive == "#ifdef")
{
HandleIfDef(ret, tokens, i, defines, file_locator);
}
else if (directive == "#define")
{
HandleDefine(ret, tokens, i, defines, file_locator);
}
else if (directive == "#error")
{
HandleError(ret, tokens, i, defines, file_locator);
}
else if (directive == "#warning")
{
HandleWarning(ret, tokens, i, defines, file_locator);
}
else if (directive == "#pragma")
{
HandlePragma(ret, tokens, i, defines, file_locator);
}
else if (directive == "#ifndef")
{
HandleIfndef(ret, tokens, i, defines, file_locator);
}
else
{
throw new Exception("Unsupported preprocessor directive: " + tok.value);
}
}
else
{
if ((tok.type == token.token_type.identifier) && defines.ContainsKey(tok.value))
{
ret.AddRange(defines[tok.value]);
}
else
{
ret.Add(tok);
}
}
}
return(ret);
}
