Fix complaints about escape sequences.

Discussed starting at
<http://lists.gnu.org/archive/html/bison-patches/2009-08/msg00036.html>.
* src/scan-gram.l (SC_ESCAPED_STRING, SC_ESCAPED_CHARACTER):
For a \0 and similar escape sequences meaning the null
character, report an invalid escape sequence instead of an
invalid null character because the latter does not actually
appear in the user's input.
In all escape sequence complaints, don't escape the initial
backslash, and don't quote when the sequence appears at the end
of the complaint line unless there's whitespace that quotearg
won't escape.
Consistently say "invalid" not "unrecognized".
* tests/input.at (Bad escapes in literals): New.
(cherry picked from commit c2724603c9d87e816dbdf1a9bfd7d70ffc1bd137)

Conflicts:

	tests/input.at

diff --git a/ChangeLog b/ChangeLog
index 86a3c496de4f950a8b0e6910669db878e3875452..3874c978fb65b0eef3294bbf6519373cf6ffad00 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,20 @@
+2009-08-19  Joel E. Denny  <jdenny@clemson.edu>
+
+       Fix complaints about escape sequences.
+       Discussed starting at
+       <http://lists.gnu.org/archive/html/bison-patches/2009-08/msg00036.html>.
+       * src/scan-gram.l (SC_ESCAPED_STRING, SC_ESCAPED_CHARACTER):
+       For a \0 and similar escape sequences meaning the null
+       character, report an invalid escape sequence instead of an
+       invalid null character because the latter does not actually
+       appear in the user's input.
+       In all escape sequence complaints, don't escape the initial
+       backslash, and don't quote when the sequence appears at the end
+       of the complaint line unless there's whitespace that quotearg
+       won't escape.
+       Consistently say "invalid" not "unrecognized".
+       * tests/input.at (Bad escapes in literals): New.
+
 2009-08-19  Akim Demaille  <demaille@gostai.com>
 
        doc: %initial-action to initialize yylloc.

diff --git a/src/scan-gram.l b/src/scan-gram.l
index 110c339dc5ca5f0a91f0ffe5db3c11d0ee587ddb..683d58225b57e1fd664c87700517d2708a2fef6e 100644 (file)
--- a/src/scan-gram.l
+++ b/src/scan-gram.l
@@ -37,6 +37,7 @@
 #include "reader.h"
 #include "uniqstr.h"
 
+#include <ctype.h>
 #include <mbswidth.h>
 #include <quote.h>
 
@@ -399,10 +400,9 @@ splice      (\\[ \f\t\v]*\n)*
 {
   \\[0-7]{1,3} {
     unsigned long int c = strtoul (yytext + 1, NULL, 8);
-    if (UCHAR_MAX < c)
-      complain_at (*loc, _("invalid escape sequence: %s"), quote (yytext));
-    else if (! c)
-      complain_at (*loc, _("invalid null character: %s"), quote (yytext));
+    if (!c || UCHAR_MAX < c)
+      complain_at (*loc, _("invalid number after \\-escape: %s"),
+                   yytext+1);
     else
       obstack_1grow (&obstack_for_string, c);
   }
@@ -410,10 +410,9 @@ splice      (\\[ \f\t\v]*\n)*
   \\x[0-9abcdefABCDEF]+ {
     verify (UCHAR_MAX < ULONG_MAX);
     unsigned long int c = strtoul (yytext + 2, NULL, 16);
-    if (UCHAR_MAX < c)
-      complain_at (*loc, _("invalid escape sequence: %s"), quote (yytext));
-    else if (! c)
-      complain_at (*loc, _("invalid null character: %s"), quote (yytext));
+    if (!c || UCHAR_MAX < c)
+      complain_at (*loc, _("invalid number after \\-escape: %s"),
+                   yytext+1);
     else
       obstack_1grow (&obstack_for_string, c);
   }
@@ -431,16 +430,23 @@ splice     (\\[ \f\t\v]*\n)*
 
   \\(u|U[0-9abcdefABCDEF]{4})[0-9abcdefABCDEF]{4} {
     int c = convert_ucn_to_byte (yytext);
-    if (c < 0)
-      complain_at (*loc, _("invalid escape sequence: %s"), quote (yytext));
-    else if (! c)
-      complain_at (*loc, _("invalid null character: %s"), quote (yytext));
+    if (c <= 0)
+      complain_at (*loc, _("invalid number after \\-escape: %s"),
+                   yytext+1);
     else
       obstack_1grow (&obstack_for_string, c);
   }
   \\(.|\n)     {
-    complain_at (*loc, _("unrecognized escape sequence: %s"), quote (yytext));
-    STRING_GROW;
+    char const *p = yytext + 1;
+    char quoted_ws[] = "` '";
+    if (isspace (*p) && isprint (*p))
+      {
+        quoted_ws[1] = *p;
+        p = quoted_ws;
+      }
+    else
+      p = quotearg_style_mem (escape_quoting_style, p, 1);
+    complain_at (*loc, _("invalid character after \\-escape: %s"), p);
   }
 }
 

diff --git a/tests/input.at b/tests/input.at
index 00c4b2be88249c6ecf52a6018a684e22c3233ed5..1a63d7e88f82836aab0c935528d580c4aebee875 100644 (file)
--- a/tests/input.at
+++ b/tests/input.at
@@ -940,3 +940,36 @@ AT_CHECK_NAMESPACE_ERROR([[::]],
                          [[namespace reference has a trailing "::"]])
 
 AT_CLEANUP
+
+## ------------------------- ##
+## Bad escapes in literals.  ##
+## ------------------------- ##
+
+AT_SETUP([[Bad escapes in literals]])
+
+AT_DATA([input.y],
+[[%%
+start: '\777' '\0' '\xfff' '\x0'
+       '\uffff' '\u0000' '\Uffffffff' '\U00000000'
+       '\ ' '\A';
+]])
+echo 'start: "\T\F\0\1" ;' | tr 'TF01' '\011\014\0\1' >> input.y
+
+AT_BISON_CHECK([input.y], [1], [],
+[[input.y:2.9-12: invalid number after \-escape: 777
+input.y:2.16-17: invalid number after \-escape: 0
+input.y:2.21-25: invalid number after \-escape: xfff
+input.y:2.29-31: invalid number after \-escape: x0
+input.y:3.9-14: invalid number after \-escape: uffff
+input.y:3.18-23: invalid number after \-escape: u0000
+input.y:3.27-36: invalid number after \-escape: Uffffffff
+input.y:3.40-49: invalid number after \-escape: U00000000
+input.y:4.9-10: invalid character after \-escape: ` '
+input.y:4.14-15: invalid character after \-escape: A
+input.y:5.9-16: invalid character after \-escape: \t
+input.y:5.17: invalid character after \-escape: \f
+input.y:5.18: invalid character after \-escape: \0
+input.y:5.19: invalid character after \-escape: \001
+]])
+
+AT_CLEANUP