diff options
Diffstat (limited to 'gdb/c-lang.c')
| -rw-r--r-- | gdb/c-lang.c | 25 |
1 files changed, 22 insertions, 3 deletions
diff --git a/gdb/c-lang.c b/gdb/c-lang.c index eecc76d..2c075f4 100644 --- a/gdb/c-lang.c +++ b/gdb/c-lang.c @@ -227,9 +227,13 @@ c_printstr (struct ui_file *stream, struct type *type, until a null character of the appropriate width is found, otherwise the string is read to the length of characters specified. The size of a character is determined by the length of the target type of - the pointer or array. If VALUE is an array with a known length, - the function will not read past the end of the array. On - completion, *LENGTH will be set to the size of the string read in + the pointer or array. + + If VALUE is an array with a known length, and *LENGTH is -1, + the function will not read past the end of the array. However, any + declared size of the array is ignored if *LENGTH > 0. + + On completion, *LENGTH will be set to the size of the string read in characters. (If a length of -1 is specified, the length returned will not include the null character). CHARSET is always set to the target charset. */ @@ -309,6 +313,21 @@ c_get_string (struct value *value, gdb_byte **buffer, { CORE_ADDR addr = value_as_address (value); + /* Prior to the fix for PR 16196 read_string would ignore fetchlimit + if length > 0. The old "broken" behaviour is the behaviour we want: + The caller may want to fetch 100 bytes from a variable length array + implemented using the common idiom of having an array of length 1 at + the end of a struct. In this case we want to ignore the declared + size of the array. However, it's counterintuitive to implement that + behaviour in read_string: what does fetchlimit otherwise mean if + length > 0. Therefore we implement the behaviour we want here: + If *length > 0, don't specify a fetchlimit. This preserves the + previous behaviour. We could move this check above where we know + whether the array is declared with a fixed size, but we only want + to apply this behaviour when calling read_string. PR 16286. */ + if (*length > 0) + fetchlimit = UINT_MAX; + err = read_string (addr, *length, width, fetchlimit, byte_order, buffer, length); if (err) |