diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6f50aca0797cb2d3a2b61796d43137fb417f76ee..fe2cc6b42ebe6661bdf942428757e8a19aef25ba 100755
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -42,13 +42,6 @@ INCLUDE(cmake/env.inc)
 INCLUDE(cmake/version.inc)
 INCLUDE(cmake/install.inc)
 
-IF (CMAKE_SYSTEM_NAME MATCHES "Linux")
-  SET(CMAKE_C_FLAGS   "${CMAKE_C_FLAGS} -pipe -Wall -Wshadow -Werror")
-  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -pipe -Wall -Wshadow -Werror")
-ENDIF ()
-MESSAGE(STATUS "CMAKE_C_FLAGS:   ${CMAKE_C_FLAGS}")
-MESSAGE(STATUS "CMAKE_CXX_FLAGS: ${CMAKE_CXX_FLAGS}")
-
 ADD_SUBDIRECTORY(deps)
 ADD_SUBDIRECTORY(src)
 ADD_SUBDIRECTORY(tests)
diff --git a/cmake/define.inc b/cmake/define.inc
index d6a3f2b915fca1a766c06abc412eb8ce60522ef0..dc3ea3a0b274c852eab048c172aac3b8a5758511 100755
--- a/cmake/define.inc
+++ b/cmake/define.inc
@@ -178,7 +178,7 @@ IF (TD_WINDOWS)
       MESSAGE("memory sanitizer detected as false")
       SET(DEBUG_FLAGS "/Zi /W3 /GL")
     ENDIF ()
-    SET(RELEASE_FLAGS "/W0 /O3 /GL")
+    SET(RELEASE_FLAGS "/W0 /O2 /GL")  # MSVC only support O2
   ENDIF ()
 
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/deps/pthread)
@@ -201,6 +201,10 @@ IF (TD_WINDOWS_32)
   MESSAGE(STATUS "windows32 is defined")
 ENDIF ()
 
+IF (TD_LINUX)
+  SET(COMMON_FLAGS "${COMMON_FLAGS} -pipe -Wshadow")
+ENDIF ()
+
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
diff --git a/src/os/src/detail/osSysinfo.c b/src/os/src/detail/osSysinfo.c
index 891dccaf9779016065013d4f59580026fb98352a..04b1efe7bf78d57a8806960995b0e34ff79e3abb 100644
--- a/src/os/src/detail/osSysinfo.c
+++ b/src/os/src/detail/osSysinfo.c
@@ -74,13 +74,14 @@ bool taosGetProcMemory(float *memoryUsedMB) {
     return false;
   }
 
+  ssize_t _bytes = 0;
   size_t len;
   char * line = NULL;
   while (!feof(fp)) {
     tfree(line);
     len = 0;
-    getline(&line, &len, fp);
-    if (line == NULL) {
+    _bytes = getline(&line, &len, fp);
+    if ((_bytes < 0) || (line == NULL)) {
       break;
     }
     if (strstr(line, "VmRSS:") != NULL) {
@@ -113,8 +114,8 @@ static bool taosGetSysCpuInfo(SysCpuInfo *cpuInfo) {
 
   size_t len;
   char * line = NULL;
-  getline(&line, &len, fp);
-  if (line == NULL) {
+  ssize_t _bytes = getline(&line, &len, fp);
+  if ((_bytes < 0) || (line == NULL)) {
     uError("read file:%s failed", tsSysCpuFile);
     fclose(fp);
     return false;
@@ -138,8 +139,8 @@ static bool taosGetProcCpuInfo(ProcCpuInfo *cpuInfo) {
 
   size_t len = 0;
   char * line = NULL;
-  getline(&line, &len, fp);
-  if (line == NULL) {
+  ssize_t _bytes = getline(&line, &len, fp);
+  if ((_bytes < 0) || (line == NULL)) {
     uError("read file:%s failed", tsProcCpuFile);
     fclose(fp);
     return false;
@@ -339,6 +340,7 @@ static bool taosGetCardInfo(int64_t *bytes) {
     return false;
   }
 
+  ssize_t _bytes = 0;
   size_t len = 2048;
   char * line = calloc(1, len);
 
@@ -357,7 +359,12 @@ static bool taosGetCardInfo(int64_t *bytes) {
     int64_t nouse6 = 0;
     char    nouse0[200] = {0};
 
-    getline(&line, &len, fp);
+    _bytes = getline(&line, &len, fp);
+    if (_bytes < 0)
+    {
+      break;
+    }
+
     line[len - 1] = 0;
 
     if (strstr(line, "lo:") != NULL) {
@@ -420,6 +427,7 @@ static bool taosReadProcIO(int64_t *readbyte, int64_t *writebyte) {
     return false;
   }
 
+  ssize_t _bytes = 0;
   size_t len;
   char * line = NULL;
   char   tmp[10];
@@ -428,8 +436,8 @@ static bool taosReadProcIO(int64_t *readbyte, int64_t *writebyte) {
   while (!feof(fp)) {
     tfree(line);
     len = 0;
-    getline(&line, &len, fp);
-    if (line == NULL) {
+    _bytes = getline(&line, &len, fp);
+    if ((_bytes < 0) || (line == NULL)) {
       break;
     }
     if (strstr(line, "rchar:") != NULL) {
diff --git a/src/plugins/http/src/httpJson.c b/src/plugins/http/src/httpJson.c
index df4c4fbc63d469c22ea13273564bec49562f35a9..10300e93670b5e10f56259d51b6ca31df3e90e39 100644
--- a/src/plugins/http/src/httpJson.c
+++ b/src/plugins/http/src/httpJson.c
@@ -297,6 +297,7 @@ void httpJsonTimestamp(JsonBuf* buf, int64_t t, int32_t timePrecision) {
     }
 
     default:
+      fractionLen = 0;
       assert(false);
   }
 
@@ -342,6 +343,7 @@ void httpJsonUtcTimestamp(JsonBuf* buf, int64_t t, int32_t timePrecision) {
     }
 
     default:
+      fractionLen = 0;
       assert(false);
   }
 
diff --git a/src/util/src/tbuffer.c b/src/util/src/tbuffer.c
index abfa35f42cc9798d3a8a7dd7d6b874705ace88ba..c06d1e59bd537bc009b462f0b17b9cdd00321d20 100644
--- a/src/util/src/tbuffer.c
+++ b/src/util/src/tbuffer.c
@@ -18,6 +18,24 @@
 #include "exception.h"
 #include "taoserror.h"
 
+typedef union Un4B {
+  uint32_t ui;
+  float     f;
+} Un4B;
+#if __STDC_VERSION__ >= 201112L
+static_assert(sizeof(Un4B) == sizeof(uint32_t), "sizeof(Un4B) must equal to sizeof(uint32_t)");
+static_assert(sizeof(Un4B) == sizeof(float), "sizeof(Un4B) must equal to sizeof(float)");
+#endif
+
+typedef union Un8B {
+  uint64_t ull;
+  double     d;
+} Un8B;
+#if __STDC_VERSION__ >= 201112L
+static_assert(sizeof(Un8B) == sizeof(uint64_t), "sizeof(Un8B) must equal to sizeof(uint64_t)");
+static_assert(sizeof(Un8B) == sizeof(double), "sizeof(Un8B) must equal to sizeof(double)");
+#endif
+
 ////////////////////////////////////////////////////////////////////////////////
 // reader functions
 
@@ -175,13 +193,21 @@ uint64_t tbufReadUint64( SBufferReader* buf ) {
 }
 
 float tbufReadFloat( SBufferReader* buf ) {
-  uint32_t ret = tbufReadUint32( buf );
-  return *(float*)( &ret );
+  Un4B _un;
+  tbufReadToBuffer( buf, &_un, sizeof(_un) );
+  if( buf->endian ) {
+    _un.ui = ntohl( _un.ui );
+  }
+  return _un.f;
 }
 
 double tbufReadDouble(SBufferReader* buf) {
-  uint64_t ret = tbufReadUint64( buf );
-  return *(double*)( &ret );
+  Un8B _un;
+  tbufReadToBuffer( buf, &_un, sizeof(_un) );
+  if( buf->endian ) {
+    _un.ull = htobe64( _un.ull );
+  }
+  return _un.d;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -381,17 +407,37 @@ void tbufWriteUint64At( SBufferWriter* buf, size_t pos, uint64_t data ) {
 }
 
 void tbufWriteFloat( SBufferWriter* buf, float data ) {
-  tbufWriteUint32( buf, *(uint32_t*)(&data) );
+  Un4B _un;
+  _un.f = data;
+  if( buf->endian ) {
+    _un.ui = htonl( _un.ui );
+  }
+  tbufWrite( buf, &_un, sizeof(_un) );
 }
 
 void tbufWriteFloatAt( SBufferWriter* buf, size_t pos, float data ) {
-  tbufWriteUint32At( buf, pos, *(uint32_t*)(&data) );
+  Un4B _un;
+  _un.f = data;
+  if( buf->endian ) {
+    _un.ui = htonl( _un.ui );
+  }
+  tbufWriteAt( buf, pos, &_un, sizeof(_un) );
 }
 
 void tbufWriteDouble( SBufferWriter* buf, double data ) {
-  tbufWriteUint64( buf, *(uint64_t*)(&data) );
+  Un8B _un;
+  _un.d = data;
+  if( buf->endian ) {
+    _un.ull = htobe64( _un.ull );
+  }
+  tbufWrite( buf, &_un, sizeof(_un) );
 }
 
 void tbufWriteDoubleAt( SBufferWriter* buf, size_t pos, double data ) {
-  tbufWriteUint64At( buf, pos, *(uint64_t*)(&data) );
+  Un8B _un;
+  _un.d = data;
+  if( buf->endian ) {
+    _un.ull = htobe64( _un.ull );
+  }
+  tbufWriteAt( buf, pos, &_un, sizeof(_un) );
 }
diff --git a/src/util/src/tconfig.c b/src/util/src/tconfig.c
index 442e83bb4f76499d7ce39792fc188d61536910c2..30d53af4b978c1c697a3ac892bad9b279af1252c 100644
--- a/src/util/src/tconfig.c
+++ b/src/util/src/tconfig.c
@@ -327,7 +327,8 @@ void taosReadGlobalLogCfg() {
     printf("\nconfig file:%s not found, all variables are set to default\n", fileName);
     return;
   }
-  
+
+  ssize_t _bytes = 0;
   size_t len = 1024;
   line = calloc(1, len);
   
@@ -337,7 +338,12 @@ void taosReadGlobalLogCfg() {
     option = value = NULL;
     olen = vlen = 0;
 
-    tgetline(&line, &len, fp);
+    _bytes = tgetline(&line, &len, fp);
+    if (_bytes < 0)
+    {
+      break;
+    }
+
     line[len - 1] = 0;
 
     paGetToken(line, &option, &olen);
@@ -373,7 +379,8 @@ bool taosReadGlobalCfg() {
       return false;
     }
   }
-  
+
+  ssize_t _bytes = 0;
   size_t len = 1024;
   line = calloc(1, len);
   
@@ -383,7 +390,12 @@ bool taosReadGlobalCfg() {
     option = value = value2 = value3 = NULL;
     olen = vlen = vlen2 = vlen3 = 0;
 
-    tgetline(&line, &len, fp);
+    _bytes = tgetline(&line, &len, fp);
+    if (_bytes < 0)
+    {
+      break;
+    }
+
     line[len - 1] = 0;
     
     paGetToken(line, &option, &olen);
diff --git a/src/util/src/tutil.c b/src/util/src/tutil.c
index bda52936f90d07b1fde598de9ca683c8a1b8b82a..1a73991ade1ea4617fc4d3dab3904652ff46d691 100644
--- a/src/util/src/tutil.c
+++ b/src/util/src/tutil.c
@@ -427,13 +427,23 @@ char *taosIpStr(uint32_t ipInt) {
 }
 
 FORCE_INLINE float taos_align_get_float(const char* pBuf) {
-  float fv = 0; 
-  *(int32_t*)(&fv) = *(int32_t*)pBuf;
+#if __STDC_VERSION__ >= 201112L
+  static_assert(sizeof(float) == sizeof(uint32_t), "sizeof(float) must equal to sizeof(uint32_t)");
+#else
+  assert(sizeof(float) == sizeof(uint32_t));
+#endif
+  float fv = 0;
+  memcpy(&fv, pBuf, sizeof(fv)); // in ARM, return *((const float*)(pBuf)) may cause problem
   return fv; 
 }
 
 FORCE_INLINE double taos_align_get_double(const char* pBuf) {
-  double dv = 0; 
-  *(int64_t*)(&dv) = *(int64_t*)pBuf;
+#if __STDC_VERSION__ >= 201112L
+  static_assert(sizeof(double) == sizeof(uint64_t), "sizeof(double) must equal to sizeof(uint64_t)");
+#else
+  assert(sizeof(double) == sizeof(uint64_t));
+#endif
+  double dv = 0;
+  memcpy(&dv, pBuf, sizeof(dv)); // in ARM, return *((const double*)(pBuf)) may cause problem
   return dv; 
 }