1 /*===-- FileLexer.l - Scanner for TableGen Files ----------------*- C++ -*-===//
3 // This file defines a simple flex scanner for TableGen files. This is pretty
4 // straight-forward, except for the magic to handle file inclusion.
6 //===----------------------------------------------------------------------===*/
11 %option never-interactive
15 %option outfile="Lexer.cpp"
24 typedef std::pair<Record*, std::vector<Init*>*> SubClassRefTy;
25 #include "FileParser.h"
27 // Global variable recording the location of the include directory
28 std::string IncludeDirectory;
30 // ParseInt - This has to handle the special case of binary numbers 0b0101
31 static int ParseInt(const char *Str) {
32 if (Str[0] == '0' && Str[1] == 'b')
33 return strtol(Str+2, 0, 2);
34 return strtol(Str, 0, 0);
37 static int CommentDepth = 0;
43 YY_BUFFER_STATE Buffer;
45 IncludeRec(const std::string &FN, FILE *F)
46 : Filename(FN), File(F), LineNo(0){
50 static std::vector<IncludeRec> IncludeStack;
54 if (IncludeStack.empty())
55 return std::cerr << "At end of input: ";
57 for (unsigned i = 0, e = IncludeStack.size()-1; i != e; ++i)
58 std::cerr << "Included from " << IncludeStack[i].Filename << ":"
59 << IncludeStack[i].LineNo << ":\n";
60 return std::cerr << "Parsing " << IncludeStack.back().Filename << ":"
61 << Filelineno << ": ";
68 // Function: ParseFile()
71 // This function begins the parsing of the specified tablegen file.
74 // Filename - A string containing the name of the file to parse.
75 // IncludeDir - A string containing the directory from which include
76 // files can be found.
78 void ParseFile(const std::string &Filename, const std::string & IncludeDir) {
80 if (Filename != "-") {
81 F = fopen(Filename.c_str(), "r");
84 std::cerr << "Could not open input file '" + Filename + "'!\n";
87 IncludeStack.push_back(IncludeRec(Filename, F));
89 IncludeStack.push_back(IncludeRec("<stdin>", stdin));
93 // Record the location of the include directory so that the lexer can find
96 IncludeDirectory = IncludeDir;
104 // HandleInclude - This function is called when an include directive is
105 // encountered in the input stream...
106 static void HandleInclude(const char *Buffer) {
107 unsigned Length = yyleng;
108 assert(Buffer[Length-1] == '"');
109 Buffer += strlen("include ");
110 Length -= strlen("include ");
111 while (*Buffer != '"') {
115 assert(Length >= 2 && "Double quotes not found?");
116 std::string Filename(Buffer+1, Buffer+Length-1);
117 //std::cerr << "Filename = '" << Filename << "'\n";
119 // Save the line number and lex buffer of the includer...
120 IncludeStack.back().LineNo = Filelineno;
121 IncludeStack.back().Buffer = YY_CURRENT_BUFFER;
123 // Open the new input file...
124 yyin = fopen(Filename.c_str(), "r");
127 // If we couldn't find the file in the current directory, look for it in
128 // the include directories.
131 // Right now, there is only one directory. We need to eventually add
134 Filename = IncludeDirectory + "/" + Filename;
135 yyin = fopen(Filename.c_str(), "r");
137 err() << "Could not find include file '" << Filename << "'!\n";
142 // Add the file to our include stack...
143 IncludeStack.push_back(IncludeRec(Filename, yyin));
144 Filelineno = 1; // Reset line numbering...
145 //yyrestart(yyin); // Start lexing the new file...
147 yy_switch_to_buffer(yy_create_buffer(yyin, YY_BUF_SIZE));
151 // yywrap - This is called when the lexer runs out of input in one of the files.
152 // Switch back to an includer if an includee has run out of input.
156 if (IncludeStack.back().File != stdin)
157 fclose(IncludeStack.back().File);
158 IncludeStack.pop_back();
159 if (IncludeStack.empty()) return 1; // Top-level file is done.
161 // Otherwise, we need to switch back to a file which included the current one.
162 Filelineno = IncludeStack.back().LineNo; // Restore current line number
163 yy_switch_to_buffer(IncludeStack.back().Buffer);
171 Identifier [a-zA-Z_][0-9a-zA-Z_]*
172 Integer [-+]?[0-9]+|0x[0-9a-fA-F]+|0b[01]+
173 CodeFragment \[\{([^}]+|\}[^\]])*\}\]
175 IncludeStr include[ \t\n]+\"[^"]*\"
179 {Comment} { /* Ignore comments */ }
181 {IncludeStr} { HandleInclude(yytext); }
182 {CodeFragment} { Filelval.StrVal = new std::string(yytext+2, yytext+yyleng-2);
183 return CODEFRAGMENT; }
187 bits { return BITS; }
188 string { return STRING; }
189 list { return LIST; }
190 code { return CODE; }
193 class { return CLASS; }
195 field { return FIELD; }
199 {Identifier} { Filelval.StrVal = new std::string(yytext, yytext+yyleng);
201 ${Identifier} { Filelval.StrVal = new std::string(yytext+1, yytext+yyleng);
204 {StringVal} { Filelval.StrVal = new std::string(yytext+1, yytext+yyleng-1);
207 {Integer} { Filelval.IntVal = ParseInt(Filetext); return INTVAL; }
209 [ \t\n]+ { /* Ignore whitespace */ }
212 "/*" { BEGIN(comment); CommentDepth++; }
213 <comment>[^*/]* /* eat anything that's not a '*' or '/' */
214 <comment>"*"+[^*/]* /* eat up '*'s not followed by '/'s */
215 <comment>"/*" { ++CommentDepth; }
216 <comment>"/"+[^*]* /* eat up /'s not followed by *'s */
217 <comment>"*"+"/" { if (!--CommentDepth) { BEGIN(INITIAL); } }
218 <comment><<EOF>> { err() << "Unterminated comment!\n"; abort(); }
220 . { return Filetext[0]; }