From: Claes Jakobsson <claes@surfar.nu>
Date: Thu, 14 May 2009 14:10:06 +0000 (+0200)
Subject: Amelioration of the error message "Unrecognized character %s in column %d"
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=b1fc363696b1a308e6bce75eb292bacc8f2c9833;p=p5sagit%2Fp5-mst-13.2.git

Amelioration of the error message "Unrecognized character %s in column %d"

Changes the error message to "Unrecognized character %s; marked by <--
HERE after %s<-- HERE near column %d". This should make it a little
simpler to spot and correct the suspicious character.
---

diff --git a/pod/perldiag.pod b/pod/perldiag.pod
index f2a4a1a..1dbb3e4 100644
--- a/pod/perldiag.pod
+++ b/pod/perldiag.pod
@@ -4423,10 +4423,10 @@ reserved word.  It's best to put such a word in quotes, or capitalize it
 somehow, or insert an underbar into it.  You might also declare it as a
 subroutine.
 
-=item Unrecognized character %s in column %d
+=item Unrecognized character %s; marked by <-- HERE after %s near column %d
 
 (F) The Perl parser has no idea what to do with the specified character
-in your Perl script (or eval) at the specified column.  Perhaps you tried 
+in your Perl script (or eval) near the specified column.  Perhaps you tried 
 to run a compressed script, a binary program, or a directory as a Perl program.
 
 =item Unrecognized escape \\%c in character class passed through in regex; marked by <-- HERE in m/%s/
diff --git a/t/base/lex.t b/t/base/lex.t
index 1b8045b..8cadf85 100755
--- a/t/base/lex.t
+++ b/t/base/lex.t
@@ -265,7 +265,7 @@ sub foo::::::bar { print "ok $test\n"; $test++ }
 foo::::::bar;
 
 eval "\$x =\xE2foo";
-if ($@ =~ /Unrecognized character \\xE2 in column 5/) { print "ok $test\n"; } else { print "not ok $test\n"; }
+if ($@ =~ /Unrecognized character \\xE2; marked by <-- HERE after \$x =<-- HERE near column 5/) { print "ok $test\n"; } else { print "not ok $test\n"; }
 $test++;
 
 # Is "[~" scanned correctly?
diff --git a/toke.c b/toke.c
index c803a80..3fda3a5 100644
--- a/toke.c
+++ b/toke.c
@@ -124,6 +124,9 @@ static I32 utf16rev_textfilter(pTHX_ int idx, SV *sv, int maxlen);
 #   define UTF ((PL_linestr && DO_UTF8(PL_linestr)) || (PL_hints & HINT_UTF8))
 #endif
 
+/* The maximum number of characters preceding the unrecognized one to display */
+#define UNRECOGNIZED_PRECEDE_COUNT 10
+
 /* In variables named $^X, these are the legal values for X.
  * 1999-02-27 mjd-perl-patch@plover.com */
 #define isCONTROLVAR(x) (isUPPER(x) || strchr("[\\]^_?", (x)))
@@ -3652,8 +3655,17 @@ Perl_yylex(pTHX)
     default:
 	if (isIDFIRST_lazy_if(s,UTF))
 	    goto keylookup;
-	len = UTF ? Perl_utf8_length(aTHX_ (U8 *) PL_linestart, (U8 *) s) : (STRLEN) (s - PL_linestart);
-	Perl_croak(aTHX_ "Unrecognized character \\x%02X in column %d", *s & 255, (int) len + 1);
+	{
+        unsigned char c = *s;
+        len = UTF ? Perl_utf8_length(aTHX_ (U8 *) PL_linestart, (U8 *) s) : (STRLEN) (s - PL_linestart);
+        if (len > UNRECOGNIZED_PRECEDE_COUNT) {
+            d = UTF ? (char *) Perl_utf8_hop(aTHX_ (U8 *) s, -UNRECOGNIZED_PRECEDE_COUNT) : s - UNRECOGNIZED_PRECEDE_COUNT;
+        } else {
+            d = PL_linestart;
+        }	
+        *s = '\0';
+        Perl_croak(aTHX_ "Unrecognized character \\x%02X; marked by <-- HERE after %s<-- HERE near column %d", c, d, (int) len + 1);
+    }
     case 4:
     case 26:
 	goto fake_eof;			/* emulate EOF on ^D or ^Z */