Warn about character literals not of length one.

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

diff --git a/src/scan-gram.l b/src/scan-gram.l
index 279bba974b11922b773b88ce7b773cfce9353a23..5c0418c630479b65c62445cacc0164aa6a76dfdc 100644 (file)
--- a/src/scan-gram.l
+++ b/src/scan-gram.l
@@ -70,7 +70,7 @@ static size_t no_cr_read (FILE *, char *, size_t);
 /* A string representing the most recently saved token.  */
 static char *last_string;
 
-/* Bracketed identifier */
+/* Bracketed identifier. */
 static uniqstr bracketed_id_str = 0;
 static location bracketed_id_loc;
 static boundary bracketed_id_start;
@@ -108,7 +108,7 @@ static void unexpected_newline (boundary, char const *);
 %x SC_COMMENT SC_LINE_COMMENT
  /* Strings and characters in code. */
 %x SC_STRING SC_CHARACTER
- /* Bracketed identifiers support */
+ /* Bracketed identifiers support. */
 %x SC_BRACKETED_ID SC_RETURN_BRACKETED_ID
 
 letter   [-.abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_]
@@ -260,7 +260,7 @@ splice       (\\[ \f\t\v]*\n)*
     complain_at (*loc, _("invalid identifier: %s"), quote (yytext));
   }
 
-  /* Characters.  We don't check there is only one.  */
+  /* Characters.  */
   "'"        STRING_GROW; token_start = loc->start; BEGIN SC_ESCAPED_CHARACTER;
 
   /* Strings. */
@@ -336,19 +336,19 @@ splice     (\\[ \f\t\v]*\n)*
 <SC_AFTER_IDENTIFIER>
 {
   "[" {
-    if (!bracketed_id_str)
-      {
-       bracketed_id_start = loc->start;
-       bracketed_id_context_state = YY_START;
-       BEGIN SC_BRACKETED_ID;
-      }
-    else
+    if (bracketed_id_str)
       {
        ROLLBACK_CURRENT_TOKEN;
        BEGIN SC_RETURN_BRACKETED_ID;
        *loc = id_loc;
        return ID;
       }
+    else
+      {
+       bracketed_id_start = loc->start;
+       bracketed_id_context_state = YY_START;
+       BEGIN SC_BRACKETED_ID;
+      }
   }
   ":" {
     BEGIN (bracketed_id_str ? SC_RETURN_BRACKETED_ID : INITIAL);
@@ -375,15 +375,15 @@ splice     (\\[ \f\t\v]*\n)*
 <SC_BRACKETED_ID>
 {
   {id} {
-    if (!bracketed_id_str)
+    if (bracketed_id_str)
       {
-       bracketed_id_str = uniqstr_new (yytext);
-       bracketed_id_loc = *loc;
+       complain_at (*loc, _("unexpected identifier in bracketed name: %s"),
+                    quote (yytext));
       }
     else
       {
-       complain_at (*loc, _("redundant identifier in bracketed name: %s"),
-                    quote (yytext));
+       bracketed_id_str = uniqstr_new (yytext);
+       bracketed_id_loc = *loc;
       }
   }
   "]" {
@@ -399,7 +399,7 @@ splice       (\\[ \f\t\v]*\n)*
          }
       }
     else
-      complain_at (*loc, _("a non empty identifier expected"));
+      complain_at (*loc, _("an identifier expected"));
   }
   . {
     complain_at (*loc, _("invalid character in bracketed name: %s"),
@@ -493,24 +493,40 @@ 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];
+    {
+      /* FIXME: Eventually, make these errors.  */
+      size_t length = strlen (last_string);
+      if (strlen (last_string) < 3)
+        warn_at (*loc, _("empty character literal"));
+      else if (strlen (last_string) > 3)
+        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];
+    {
+      size_t length = strlen (last_string);
+      /* FIXME: Eventually, make these errors.  */
+      if (length < 2)
+        warn_at (*loc, _("empty character literal"));
+      else if (length > 2)
+        warn_at (*loc, _("extra characters in character literal"));
+      if (length > 1)
+        val->character = last_string[1];
+      else
+        val->character = last_string[0];
+    }
+    unexpected_eof (token_start, "'");
     STRING_FREE;
     BEGIN INITIAL;
     return CHAR;