[Discuss-gnuradio] bug in gri_fft.cc

[Marek Czerski]

Hi all,

I found a bug in gnuradio-core/src/lib/general/gri_fft.cc, in function:

static const char * wisdom_filename ()

It returns pointer to char string from temporary object created by call to path.string(). Obviously, this pointer is pointing to garbage after exit from wisdom_filename() function.

I propose something like this:

 gnuradio-core/src/lib/general/gri_fft.cc | 10 ++++++----

 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/gnuradio-core/src/lib/general/gri_fft.cc b/gnuradio-core/src/lib/general/gri_fft.cc

index 68e7e69..906279b 100644

--- a/gnuradio-core/src/lib/general/gri_fft.cc

+++ b/gnuradio-core/src/lib/general/gri_fft.cc

@@ -73,18 +73,19 @@ gri_fft_planner::mutex()

   return s_planning_mutex;

 }

 

-static const char *

+static std::string

 wisdom_filename ()

 {

   static fs::path path;

   path = fs::path(gr_appdata_path()) / ".gr_fftw_wisdom";

-  return path.string().c_str();

+  return path.string();

 }

 

 static void

 gri_fftw_import_wisdom ()

 {

-  const char *filename = wisdom_filename ();

+  const std::string & s = wisdom_filename ();

+  const char *filename = s.c_str ();

   FILE *fp = fopen (filename, "r");

   if (fp != 0){

     int r = fftwf_import_wisdom_from_file (fp);

@@ -114,7 +115,8 @@ gri_fftw_config_threading (int nthreads)

 static void

 gri_fftw_export_wisdom ()

 {

-  const char *filename = wisdom_filename ();

+  const std::string & s = wisdom_filename ();

+  const char *filename = s.c_str ();

   FILE *fp = fopen (filename, "w");

   if (fp != 0){

     fftwf_export_wisdom_to_file (fp);