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| author | Akim Demaille <akim.demaille@gmail.com> | 2019-03-12 19:09:10 +0100 |
|---|---|---|
| committer | Akim Demaille <akim.demaille@gmail.com> | 2019-03-17 13:21:25 +0100 |
| commit | 35add841ee3d5e499af0f9cfae227dc3ce62227d (patch) | |
| tree | 3ce4c18bd378a70ee5e167bd2f7224d506f3f64d /src/location.c | |
| parent | f6e38d7ac97aaeb77a97e3dc0af047c89a7e4402 (diff) | |
| download | bison-35add841ee3d5e499af0f9cfae227dc3ce62227d.tar.gz | |
address warnings from GCC's UB sanitizer
Running with CC='gcc-mp-8 -fsanitize=undefined' revealed Undefined
Behaviors.
https://lists.gnu.org/archive/html/bison-patches/2019-03/msg00008.html
* src/state.c (errs_new): Don't call memcpy with NULL as source.
* src/location.c (add_column_width): Don't assume that the column
argument is nonnegative: the scanner sometimes "backtracks" (e.g., see
ROLLBACK_CURRENT_TOKEN and DEPRECATED) in which case we can have
negative column numbers (temporarily).
Found in test 3 (Invalid inputs).
Diffstat (limited to 'src/location.c')
| -rw-r--r-- | src/location.c | 23 |
1 files changed, 7 insertions, 16 deletions
diff --git a/src/location.c b/src/location.c index 3eae89be..38c84693 100644 --- a/src/location.c +++ b/src/location.c @@ -31,25 +31,16 @@ location const empty_location = EMPTY_LOCATION_INIT; /* If BUF is null, add BUFSIZE (which in this case must be less than INT_MAX) to COLUMN; otherwise, add mbsnwidth (BUF, BUFSIZE, 0) to - COLUMN. If an overflow occurs, or might occur but is undetectable, - return INT_MAX. Assume COLUMN is nonnegative. */ + COLUMN. If an overflow occurs, return INT_MAX. */ static inline int add_column_width (int column, char const *buf, size_t bufsize) { - size_t width; - unsigned remaining_columns = INT_MAX - column; - - if (buf) - { - if (INT_MAX / 2 <= bufsize) - return INT_MAX; - width = mbsnwidth (buf, bufsize, 0); - } - else - width = bufsize; - - return width <= remaining_columns ? column + width : INT_MAX; + int width + = buf ? mbsnwidth (buf, bufsize, 0) + : INT_MAX <= bufsize ? INT_MAX + : bufsize; + return column <= INT_MAX - width ? column + width : INT_MAX; } /* Set *LOC and adjust scanner cursor to account for token TOKEN of @@ -66,7 +57,7 @@ location_compute (location *loc, boundary *cur, char const *token, size_t size) loc->start = *cur; - for (p = token; p < lim; p++) + for (p = token; p < lim; ++p) switch (*p) { case '\n': |