From 47bb3f5219e438860e67ad06c0d3da03a3137184 Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Sat, 7 Apr 2018 08:27:35 -0400
Subject: [PATCH] Add lexer tokens for integer, float, string constants and
 identifiers

---
 src/parser/parser.l | 31 +++++++++++++++++++++++++++++++
 src/parser/parser.y |  7 +++++++
 2 files changed, 38 insertions(+)

diff --git a/src/parser/parser.l b/src/parser/parser.l
index 155c0e5..8b5deaf 100644
--- a/src/parser/parser.l
+++ b/src/parser/parser.l
@@ -83,4 +83,35 @@ continue            return TOK_CONTINUE;
 
 sizeof              return TOK_SIZEOF;
 
+
+'[^\\]'             return TOK_CHAR_CONST;
+'\\.'               return TOK_CHAR_CONST;
+'\\n'               (void)'\n'; return TOK_CHAR_CONST;
+'\\t'               (void)'\t'; return TOK_CHAR_CONST;
+'\\r'               (void)'\r'; return TOK_CHAR_CONST;
+'\\b'               (void)'\b'; return TOK_CHAR_CONST;
+'\\f'               (void)'\f'; return TOK_CHAR_CONST;
+[0-9]+([uU][lL]?[lL]?)?              return TOK_INT_CONST;
+0[xX][0-9a-fA-F]+([uU][lL]?[lL]?)?   return TOK_INT_CONST;
+[0-9]*\.[0-9]*[fF]? return TOK_FLOAT_CONST;
+
+\"                  BEGIN(str);
+<str>{
+\"                  return TOK_STR_CONST;
+\\x[0-9A-Fa-f]{2} {
+                    /* hexadecimal escape code */
+                    unsigned int val;
+                    (void) sscanf(yytext + 2, "%x", &val);
+}
+\\n                 (void)'\n';
+\\t                 (void)'\t';
+\\r                 (void)'\r';
+\\b                 (void)'\b';
+\\f                 (void)'\f';
+\\.                 (void)yytext[1];
+[^\\\"]+            (void)yytext;
+}
+
+[a-zA-Z_][a-zA-Z_0-9]*              return TOK_IDENTIFIER;
+
 %%
diff --git a/src/parser/parser.y b/src/parser/parser.y
index 507ee01..ff677a4 100644
--- a/src/parser/parser.y
+++ b/src/parser/parser.y
@@ -86,6 +86,13 @@ static void handle_error(const char * str, const YYLTYPE * yylloc);
 
 %token TOK_SIZEOF;
 
+
+%token TOK_CHAR_CONST;
+%token TOK_INT_CONST;
+%token TOK_FLOAT_CONST;
+%token TOK_STR_CONST;
+%token TOK_IDENTIFIER;
+
 %%
 
 translation_unit: TOK_PLUS;