From 18902be6358e54a65c166a601be20ab7cc1b84c9 Mon Sep 17 00:00:00 2001
From: Jinzhe Zeng <jinzhe.zeng@rutgers.edu>
Date: Thu, 14 Dec 2023 19:58:35 -0500
Subject: [PATCH] fix memory leaks related to `char*` (#3063)

Make sure no leaks reported from `string_to_char` by LeakSanitizer.

Most memory leaks happen only once, but `DP_CHECK_OK` causes 1 byte
leaking every step, meaning 10 MB leaks for 10 million steps.

---------

Signed-off-by: Jinzhe Zeng <jinzhe.zeng@rutgers.edu>
---
 source/api_c/include/c_api.h         |  7 +++++++
 source/api_c/include/deepmd.hpp      | 18 ++++++++++++------
 source/api_c/src/c_api.cc            |  2 ++
 source/api_c/tests/test_deeppot_a.cc |  1 +
 4 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/source/api_c/include/c_api.h b/source/api_c/include/c_api.h
index b0c030962a..d05f790bf9 100644
--- a/source/api_c/include/c_api.h
+++ b/source/api_c/include/c_api.h
@@ -1271,6 +1271,13 @@ void DP_SelectMapInt(const int* in,
                      const int nall2,
                      int* out);
 
+/**
+ * @brief Destroy a char array.
+ *
+ * @param c_str The char array.
+ */
+void DP_DeleteChar(const char* c_str);
+
 #ifdef __cplusplus
 } /* end extern "C" */
 #endif
diff --git a/source/api_c/include/deepmd.hpp b/source/api_c/include/deepmd.hpp
index 90c1c1c918..4a376e0bec 100644
--- a/source/api_c/include/deepmd.hpp
+++ b/source/api_c/include/deepmd.hpp
@@ -35,10 +35,14 @@ struct deepmd_exception : public std::runtime_error {
 /**
  * @brief Check if any exceptions throw in the C++ API. Throw if possible.
  */
-#define DP_CHECK_OK(check_func, dp)     \
-  const char *err_msg = check_func(dp); \
-  if (std::strlen(err_msg))             \
-    throw deepmd::hpp::deepmd_exception(std::string(err_msg));
+#define DP_CHECK_OK(check_func, dp)                   \
+  const char *err_msg = check_func(dp);               \
+  if (std::strlen(err_msg)) {                         \
+    std::string err_msg_str = std::string(err_msg);   \
+    DP_DeleteChar(err_msg);                           \
+    throw deepmd::hpp::deepmd_exception(err_msg_str); \
+  }                                                   \
+  DP_DeleteChar(err_msg);
 
 template <typename FPTYPE>
 inline void _DP_DeepPotCompute(DP_DeepPot *dp,
@@ -1019,7 +1023,7 @@ class DeepPot {
   void get_type_map(std::string &type_map) {
     const char *type_map_c = DP_DeepPotGetTypeMap(dp);
     type_map.assign(type_map_c);
-    delete[] type_map_c;
+    DP_DeleteChar(type_map_c);
   };
   /**
    * @brief Print the summary of DeePMD-kit, including the version and the build
@@ -1864,7 +1868,7 @@ class DeepTensor {
   void get_type_map(std::string &type_map) {
     const char *type_map_c = DP_DeepTensorGetTypeMap(dt);
     type_map.assign(type_map_c);
-    delete[] type_map_c;
+    DP_DeleteChar(type_map_c);
   };
 
  private:
@@ -2009,9 +2013,11 @@ void inline read_file_to_string(std::string model, std::string &file_content) {
   if (size < 0) {
     // negtive size indicates error
     std::string error_message = std::string(c_file_content, -size);
+    DP_DeleteChar(c_file_content);
     throw deepmd::hpp::deepmd_exception(error_message);
   }
   file_content = std::string(c_file_content, size);
+  DP_DeleteChar(c_file_content);
 };
 
 /**
diff --git a/source/api_c/src/c_api.cc b/source/api_c/src/c_api.cc
index 9d1ed7d323..935e812cf0 100644
--- a/source/api_c/src/c_api.cc
+++ b/source/api_c/src/c_api.cc
@@ -1421,4 +1421,6 @@ void DP_SelectMapInt(const int* in,
   }
 }
 
+void DP_DeleteChar(const char* c_str) { delete[] c_str; }
+
 }  // extern "C"
diff --git a/source/api_c/tests/test_deeppot_a.cc b/source/api_c/tests/test_deeppot_a.cc
index 50e8131cc0..63f53e16e9 100644
--- a/source/api_c/tests/test_deeppot_a.cc
+++ b/source/api_c/tests/test_deeppot_a.cc
@@ -172,6 +172,7 @@ TEST_F(TestInferDeepPotA, type_map) {
   const char* type_map = DP_DeepPotGetTypeMap(dp);
   char expected_type_map[] = "O H";
   EXPECT_EQ(strcmp(type_map, expected_type_map), 0);
+  DP_DeleteChar(type_map);
 }
 
 class TestInferDeepPotANoPBC : public ::testing::Test {