feat(core): add utils function to get env var in a safe way

Author: GuillaumeLagrange

core/BUILD

@@ -6,7 +6,7 @@ CODSPEED_VERSION = "1.1.1"
 # Define the codspeed library
 cc_library(
     name = "codspeed",
-    srcs = glob(["src/**/*.cpp"]),
+    srcs = glob(["src/**/*.cpp"] + ["src/**/*.h"]),
     hdrs = glob(["include/**/*.h"] + ["include/**/*.hpp"]),
     includes = ["include"],
     defines = [

core/src/utils.h

@@ -0,0 +1,13 @@
+#ifndef CODSPEED_UTILS_H
+#define CODSPEED_UTILS_H
+
+#include <string>
+
+namespace codspeed {
+
+// Cross-platform getenv wrapper
+std::string safe_getenv(const char* var_name);
+
+}  // namespace codspeed
+
+#endif  // CODSPEED_UTILS_H

core/src/walltime.cpp

@@ -9,6 +9,7 @@
 #include <string>
 
 #include "codspeed.h"
+#include "utils.h"
 #ifdef _WIN32
 #include <process.h>
 #else
@@ -31,7 +32,7 @@ struct BenchmarkStats {
   double total_time;
   uint64_t iqr_outlier_rounds;
   uint64_t stdev_outlier_rounds;
-  long iter_per_round;
+  uint64_t iter_per_round;
   uint64_t warmup_iters;
 };
 
@@ -169,8 +170,8 @@ void write_codspeed_benchmarks_to_json(
   oss << "}";
 
   // Determine the directory path
-  const char *profile_folder = std::getenv("CODSPEED_PROFILE_FOLDER");
-  std::string directory = profile_folder ? profile_folder : ".";
+  std::string profile_folder = safe_getenv("CODSPEED_PROFILE_FOLDER");
+  std::string directory = profile_folder.empty() ? "." : profile_folder;
 
   // Create the results directory if it does not exist
   std::filesystem::path results_path = directory + "/results";

core/src/workspace.cpp

@@ -3,13 +3,32 @@
 #include <filesystem>
 
 #include "codspeed.h"
+#include "utils.h"
 
 namespace codspeed {
 
-std::string get_path_relative_to_workspace(const std::string &path) {
+std::string safe_getenv(const char* var_name) {
+#ifdef _WIN32
+  // On Windows, use _dupenv_s instead of std::getenv for thread safety
+  char* value;
+  size_t len;
+  errno_t err = _dupenv_s(&value, &len, var_name);
+  if (err == 0 && value) {
+    std::string result(value);
+    free(value);
+    return result;
+  }
+  return "";
+#else
+  const char* value = std::getenv(var_name);
+  return value ? value : "";
+#endif
+}
+
+std::string get_path_relative_to_workspace(const std::string& path) {
   // 1. Check for bazel usage, through the BUILD_WORKSPACE_DIRECTORY env var
   // If so, __FILE__ will already be relative to the bazel workspace root
-  if (std::getenv("BUILD_WORKSPACE_DIRECTORY") != NULL) {
+  if (!safe_getenv("BUILD_WORKSPACE_DIRECTORY").empty()) {
     return path;
   }