From 5624f6ddd1293aa9914b59205cf1ea357483abe4 Mon Sep 17 00:00:00 2001
From: Matthias Kruk <m@m10k.eu>
Date: Sat, 4 Jul 2020 17:49:10 +0900
Subject: [PATCH] lex: Add token type for floating pointer literals and parse
 them correctly

---
 src/lex.c   | 34 ++++++++++++++++++++++++++++++----
 src/token.h |  1 +
 2 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/src/lex.c b/src/lex.c
index a0613c6..d2bc345 100644
--- a/src/lex.c
+++ b/src/lex.c
@@ -33,6 +33,7 @@
 #define STATE_DOT         22
 #define STATE_ZERO        23
 #define STATE_NUM         24
+#define STATE_FLT         25
 
 #define identifier_firstchr(_c) ((_c) == '_' ||			\
 				 (_c) >= 'a' && (_c) <= 'z' ||	\
@@ -550,7 +551,10 @@ struct token *_nexttoken(void)
 			_putnextchar(c);
 
 			if(c >= '0' && c <= '9') {
-				state = STATE_NUM;
+				tok = token_new_from_str(TOKEN_FLOAT_LITERAL, _line, _col, "0.");
+				assert(tok);
+
+				state = STATE_FLT;
 			} else {
 				return(token_new_from_str(TOKEN_MEMBER, _line, _col, "."));
 			}
@@ -565,7 +569,9 @@ struct token *_nexttoken(void)
 				_putnextchar(c);
 				state = STATE_NUM;
 			} else if(c == '.') {
-
+				token_append_char(tok, '.');
+				tok->type = TOKEN_FLOAT_LITERAL;
+				state = STATE_FLT;
 			} else {
 				_putnextchar(c);
 				return(tok);
@@ -574,9 +580,29 @@ struct token *_nexttoken(void)
 			break;
 
 		case STATE_NUM:
-			/* FIXME: e, E may be in the middle, (u|U)(l|L|ll|LL) or vice versa may be at the end */
-			if(c >= '0' && c <= '9' || c == '.') {
+			/* this state parses integer constants only - suffixes are handled by the parser */
+			if(c >= '0' && c <= '9') {
 				token_append_char(tok, c);
+			} else if(c == '.') {
+				token_append_char(tok, c);
+				tok->type = TOKEN_FLOAT_LITERAL;
+				state = STATE_FLT;
+			} else {
+				_putnextchar(c);
+				return(tok);
+			}
+
+			break;
+
+		case STATE_FLT:
+			if(c >= '0' && c <= '9' ||
+			   c == 'e' || c == 'E') {
+				token_append_char(tok, c);
+			} else if(c == '.') {
+                                fprintf(stderr, "Too many decimal points in number %d:%d ['%c']\n",
+					_line, _col, c);
+				free(tok);
+				return(NULL);
 			} else {
 				_putnextchar(c);
 				return(tok);
diff --git a/src/token.h b/src/token.h
index 3f06ba3..df02a9b 100644
--- a/src/token.h
+++ b/src/token.h
@@ -18,6 +18,7 @@ typedef enum {
 	TOKEN_ASSIGN_SUB,
 	TOKEN_ASSIGN_XOR,
 	TOKEN_CHAR_LITERAL,
+	TOKEN_FLOAT_LITERAL,
 	TOKEN_COLON,
 	TOKEN_COMMA,
 	TOKEN_COMMENT,
-- 
2.47.3