| Message ID | 388ea759-1c59-9fad-5006-1f6f70c01378@gmail.com |
|---|---|
| State | New |
| Headers | show |
On 07/27/2017 05:29 PM, Martin Sebor wrote: > The pretty printer treats precision in %s directives as a request > to print exactly as many characters from the string argument when > what precision normally (in C) means is the maximum number of > characters to read from the string. It doesn't mean to read > past the terminating NUL. > > The attached patch fixes that. Tested on x86_64-linux. > > Martin > > gcc-81586.diff > > > PR c++/81586 - valgrind error in output_buffer_append_r with -Wall > > gcc/ChangeLog: > > PR c++/81586 > * pretty-print.c (pp_format): Correct the handling of %s precision. OK. jeff
PR c++/81586 - valgrind error in output_buffer_append_r with -Wall gcc/ChangeLog: PR c++/81586 * pretty-print.c (pp_format): Correct the handling of %s precision. diff --git a/gcc/pretty-print.c b/gcc/pretty-print.c index 570dec7..a79191b 100644 --- a/gcc/pretty-print.c +++ b/gcc/pretty-print.c @@ -667,7 +667,17 @@ pp_format (pretty_printer *pp, text_info *text) } s = va_arg (*text->args_ptr, const char *); - pp_append_text (pp, s, s + n); + + /* Negative precision is treated as if it were omitted. */ + if (n < 0) + n = INT_MAX; + + /* Append the lesser of precision and strlen (s) characters. */ + size_t len = strlen (s); + if ((unsigned) n < len) + len = n; + + pp_append_text (pp, s, s + len); } break;