Miscellaneous code readability improvements.

[bison.git] / src / scan-gram.l

diff --git a/src/scan-gram.l b/src/scan-gram.l
index 60813bb620d352ee0e2dea522b085a92d19cffaa..73eb3e800a983072fc8c122eea615423281c8875 100644 (file)
--- a/src/scan-gram.l
+++ b/src/scan-gram.l
@@ -18,7 +18,7 @@
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
-%option debug nodefault nounput noyywrap never-interactive
+%option debug nodefault noinput nounput noyywrap never-interactive
 %option prefix="gram_" outfile="lex.yy.c"
 
 %{
@@ -250,8 +250,8 @@ splice       (\\[ \f\t\v]*\n)*
     complain_at (*loc, _("invalid identifier: %s"), quote (yytext));
   }
 
-  /* Characters.  We don't check there is only one.  */
-  "'"        STRING_GROW; token_start = loc->start; BEGIN SC_ESCAPED_CHARACTER;
+  /* Characters.  */
+  "'"        token_start = loc->start; BEGIN SC_ESCAPED_CHARACTER;
 
   /* Strings. */
   "\""       token_start = loc->start; BEGIN SC_ESCAPED_STRING;
@@ -465,24 +465,42 @@ splice     (\\[ \f\t\v]*\n)*
 <SC_ESCAPED_CHARACTER>
 {
   "'"|"\n" {
-    if (yytext[0] == '\n')
-      unexpected_newline (token_start, "'");
-    STRING_GROW;
     STRING_FINISH;
     loc->start = token_start;
-    val->character = last_string[1];
+    val->character = last_string[0];
+    {
+      /* FIXME: Eventually, make these errors.  */
+      if (last_string[0] == '\0')
+        {
+          warn_at (*loc, _("empty character literal"));
+          /* '\0' seems dangerous even if we are about to complain.  */
+          val->character = '\'';
+        }
+      else if (last_string[1] != '\0')
+        warn_at (*loc, _("extra characters in character literal"));
+    }
+    if (yytext[0] == '\n')
+      unexpected_newline (token_start, "'");
     STRING_FREE;
     BEGIN INITIAL;
     return CHAR;
   }
   <<EOF>> {
-    unexpected_eof (token_start, "'");
     STRING_FINISH;
     loc->start = token_start;
-    if (strlen (last_string) > 1)
-      val->character = last_string[1];
-    else
-      val->character = last_string[0];
+    val->character = last_string[0];
+    {
+      /* FIXME: Eventually, make these errors.  */
+      if (last_string[0] == '\0')
+        {
+          warn_at (*loc, _("empty character literal"));
+          /* '\0' seems dangerous even if we are about to complain.  */
+          val->character = '\'';
+        }
+      else if (last_string[1] != '\0')
+        warn_at (*loc, _("extra characters in character literal"));
+    }
+    unexpected_eof (token_start, "'");
     STRING_FREE;
     BEGIN INITIAL;
     return CHAR;