#1495: check for libunwind errors

src/vt/configs/error/stack_out.cc

@@ -43,6 +43,7 @@
 
 #include "vt/configs/error/stack_out.h"
 
+#include <fmt/core.h>
 #define UNW_LOCAL_ONLY
 #include <libunwind.h>
 #include <cxxabi.h>
@@ -56,8 +57,12 @@ DumpStackType dumpStack(int skip) {
   unw_context_t context;
 
   // Initialize cursor to current frame for local unwinding.
-  unw_getcontext(&context);
-  unw_init_local(&cursor, &context);
+  if (unw_getcontext(&context) != 0) {
+    fmt::print("unw_getcontext failed");
+  }
+  if (unw_init_local(&cursor, &context) != 0) {
+    fmt::print("unw_init_local failed");
+  }
 
   // Unwind frames one by one, going up the frame stack.
   int i = 0;
@@ -67,7 +72,9 @@ DumpStackType dumpStack(int skip) {
     }
 
     unw_word_t offset, pc;
-    unw_get_reg(&cursor, UNW_REG_IP, &pc);
+    if (unw_get_reg(&cursor, UNW_REG_IP, &pc) != 0) {
+      fmt::print("unw_get_reg failed");
+    }
     if (pc == 0) {
       break;
     }
@@ -89,7 +96,7 @@ DumpStackType dumpStack(int skip) {
       std::free(demangled);
     } else {
       // FIXME!
-      std::printf(" -- error: unable to obtain symbol name for this frame\n");
+      fmt::print(" -- error: unable to obtain symbol name for this frame\n");
     }
   }
   while (unw_step(&cursor) > 0);