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Fix complaints about escape sequences.

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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".
Consistently prefer "empty character literal" over "extra
characters in character literal" warning for invalid escape
sequences; that is, consistently discard those sequences.
* tests/input.at (Bad escapes in literals): New.
This commit is contained in:
Joel E. Denny
2009-08-19 20:37:28 -04:00
parent 17aed602c6
commit c2724603c9
3 changed files with 83 additions and 14 deletions
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20
ChangeLog
View File

@@ -1,3 +1,23 @@
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".
Consistently prefer "empty character literal" over "extra
characters in character literal" warning for invalid escape
sequences; that is, consistently discard those sequences.
* tests/input.at (Bad escapes in literals): New.
2009-08-19 Akim Demaille <demaille@gostai.com>
doc: fixes.

34
src/scan-gram.l
View File

@@ -37,6 +37,7 @@
#include <src/reader.h>
#include <src/uniqstr.h>
#include <ctype.h>
#include <mbswidth.h>
#include <quote.h>
@@ -578,10 +579,9 @@ 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);
}
@@ -589,10 +589,9 @@ 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);
}
@@ -610,16 +609,23 @@ 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);
}
}

43
tests/input.at
View File

@@ -1220,3 +1220,46 @@ three.y:4.8-11: missing `'' at end of file
]])
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:2.8-13: warning: empty character literal
input.y:2.16-17: invalid number after \-escape: 0
input.y:2.15-18: warning: empty character literal
input.y:2.21-25: invalid number after \-escape: xfff
input.y:2.20-26: warning: empty character literal
input.y:2.29-31: invalid number after \-escape: x0
input.y:2.28-32: warning: empty character literal
input.y:3.9-14: invalid number after \-escape: uffff
input.y:3.8-15: warning: empty character literal
input.y:3.18-23: invalid number after \-escape: u0000
input.y:3.17-24: warning: empty character literal
input.y:3.27-36: invalid number after \-escape: Uffffffff
input.y:3.26-37: warning: empty character literal
input.y:3.40-49: invalid number after \-escape: U00000000
input.y:3.39-50: warning: empty character literal
input.y:4.9-10: invalid character after \-escape: ` '
input.y:4.8-11: warning: empty character literal
input.y:4.14-15: invalid character after \-escape: A
input.y:4.13-16: warning: empty character literal
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