Refactor: handle in-output errors for string functions (Part 1)

velox/common/process/TraceContext.cpp

@@ -18,6 +18,7 @@
 
 #include "velox/common/process/TraceHistory.h"
 
+#include <iostream>
 #include <sstream>
 
 namespace facebook::velox::process {
@@ -41,7 +42,16 @@ TraceContext::TraceContext(std::string label, bool isTemporary)
     entry.time = enterTime_;
     entry.file = __FILE__;
     entry.line = __LINE__;
-    snprintf(entry.label, entry.kLabelCapacity, "%s", label_.c_str());
+    int result = snprintf(entry.label, entry.kLabelCapacity, "%s", label_.c_str());
+
+    if (result < 0) {
+      throw std::runtime_error("Encoding error in snprintf");
+    }
+
+    if (result >= entry.kLabelCapacity) {
+      std::cerr << "Warning: label truncated in snprintf" << std::endl;
+      entry.label[entry.kLabelCapacity - 1] = '\0';
+    }
   });
   traceData_->withValue([&](auto& counts) {
     auto& data = counts[label_];