Minor fix in safe_print function

This commit fixes two issues reported by Coverity:

- Fixes the check whether the buffer is full in safe_print_hex
- Removes dead code in safe_print for floating-point values

Additionally, it fixes an issue reported by Andy where the names of the
statistics were printed as "<unsupported>" due to calling the const char*
version instead of the std::string version of safe_print.

Finally, this fixes an issue where --segv-spin would not print the program name
because it was a const char*. The program name is now stored as a string.

NOTE: As a side effect, the last part also fixes Coverity issue 1362944, which
has been in CVC4 for a long time.

3 files changed, 6 insertions, 7 deletions

diff --git a/src/util/safe_print.cpp b/src/util/safe_print.cpp
index ff5a7aa7e..dc986e251 100644
--- a/src/util/safe_print.cpp
+++ b/src/util/safe_print.cpp
@@ -128,9 +128,8 @@ void safe_print(int fd, const double& _d) {
     d -= c;
     i++;
   }
-  if (i == 0) {
-    safe_print(fd, "0");
-  } else if (write(fd, buf, i) != i) {
+
+  if (write(fd, buf, i) != i) {
     abort();
   }
 }
@@ -172,7 +171,7 @@ void safe_print_hex(int fd, uint64_t i) {
 
   // This loop fills the buffer from the end. The number of elements in the
   // buffer is BUFER_SIZE - idx - 1 and they start at position idx + 1.
-  size_t idx = BUFFER_SIZE - 1;
+  ssize_t idx = BUFFER_SIZE - 1;
   while (i != 0 && idx >= 0) {
     char current = i % 16;
     if (current <= 9) {
diff --git a/src/util/statistics.cpp b/src/util/statistics.cpp
index 73ea5b1b1..9423c9379 100644
--- a/src/util/statistics.cpp
+++ b/src/util/statistics.cpp
@@ -122,8 +122,8 @@ void StatisticsBase::safeFlushInformation(int fd) const {
   for (StatSet::iterator i = d_stats.begin(); i != d_stats.end(); ++i) {
     Stat* s = *i;
     if (d_prefix.size() != 0) {
-      safe_print(fd, d_prefix.c_str());
-      safe_print(fd, s_regDelim.c_str());
+      safe_print(fd, d_prefix);
+      safe_print(fd, s_regDelim);
     }
     s->safeFlushStat(fd);
     safe_print(fd, "\n");
diff --git a/src/util/statistics_registry.h b/src/util/statistics_registry.h
index 1206a3e4a..bd7f87b44 100644
--- a/src/util/statistics_registry.h
+++ b/src/util/statistics_registry.h
@@ -137,7 +137,7 @@ public:
    */
   virtual void safeFlushStat(int fd) const {
     if (__CVC4_USE_STATISTICS) {
-      safe_print(fd, d_name.c_str());
+      safe_print(fd, d_name);
       safe_print(fd, ", ");
       safeFlushInformation(fd);
     }