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author | Akim Demaille <akim.demaille@gmail.com> | 2020-05-03 17:00:41 +0200 |
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committer | Akim Demaille <akim.demaille@gmail.com> | 2020-05-03 17:06:13 +0200 |
commit | 6e2de439e69ee055d65c5832dccc81fe289e6e82 (patch) | |
tree | 5d1bbe3358bfc7a441d9ab27f8396b19d5596ba3 /examples | |
parent | e33cd4b8243a42d00de21e68be49509752393406 (diff) | |
download | bison-6e2de439e69ee055d65c5832dccc81fe289e6e82.tar.gz |
bistromathic: beware of portability issues with strndup
Reported by Dagobert Michelsen.
https://lists.gnu.org/r/bug-bison/2020-05/msg00026.html
* examples/c/bistromathic/parse.y (xstrndup): New.
Use it.
Diffstat (limited to 'examples')
-rw-r--r-- | examples/c/bistromathic/parse.y | 31 |
1 files changed, 23 insertions, 8 deletions
diff --git a/examples/c/bistromathic/parse.y b/examples/c/bistromathic/parse.y index 479d1bf4..d20d4857 100644 --- a/examples/c/bistromathic/parse.y +++ b/examples/c/bistromathic/parse.y @@ -1,6 +1,7 @@ %require "3.6" %code top { + #include <assert.h> #include <ctype.h> // isdigit #include <locale.h> // LC_ALL #include <math.h> // cos, sin, etc. @@ -316,7 +317,7 @@ error_format_string (int argc) { switch (argc) { - default: /* Avoid compiler warnings. */ + default: // Avoid compiler warnings. case 0: return _("%@: syntax error"); case 1: return _("%@: syntax error: unexpected %u"); // TRANSLATORS: '%@' is a location in a file, '%u' is an @@ -393,6 +394,20 @@ void yyerror (YYLTYPE *loc, char const *format, ...) } +// Return a newly allocated copy of at most N bytes of STRING. In +// other words, return a copy of the initial segment of length N of +// STRING. +static char * +xstrndup (const char *string, size_t n) +{ + size_t len = strnlen (string, n); + char *new = malloc (len + 1); + assert (new); + new[len] = '\0'; + return memcpy (new, string, len); +} + + /*-----------. | Readline. | `-----------*/ @@ -438,11 +453,11 @@ expected_tokens (const char *input, return res; } -/* Attempt to complete on the contents of TEXT. START and END bound the - region of rl_line_buffer that contains the word to complete. TEXT is - the word to complete. We can use the entire contents of rl_line_buffer - in case we want to do some simple parsing. Return the array of matches, - or NULL if there aren't any. */ +// Attempt to complete on the contents of TEXT. START and END bound +// the region of rl_line_buffer that contains the word to complete. +// TEXT is the word to complete. We can use the entire contents of +// rl_line_buffer in case we want to do some simple parsing. Return +// the array of matches, or NULL if there aren't any. char ** completion (const char *text, int start, int end) { @@ -453,7 +468,7 @@ completion (const char *text, int start, int end) // Get list of token numbers. int tokens[YYNTOKENS]; - char *line = strndup (rl_line_buffer, start); + char *line = xstrndup (rl_line_buffer, start); int ntokens = expected_tokens (line, tokens, YYNTOKENS); free (line); @@ -495,7 +510,7 @@ completion (const char *text, int start, int end) for (int j = 0; j < lcplen; ++j) if (matches[1][j] != matches[i][j]) lcplen = j; - matches[0] = strndup (matches[1], lcplen); + matches[0] = xstrndup (matches[1], lcplen); } if (yydebug) |